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[Guile-commits] GNU Guile branch, stable-2.0, updated. v2.0.5-18-geb4a14


From: Ludovic Courtès
Subject: [Guile-commits] GNU Guile branch, stable-2.0, updated. v2.0.5-18-geb4a14e
Date: Fri, 03 Feb 2012 09:56:54 +0000

This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU Guile".

http://git.savannah.gnu.org/cgit/guile.git/commit/?id=eb4a14ed47a34e03566261b02c77bfcc02b20134

The branch, stable-2.0 has been updated
       via  eb4a14ed47a34e03566261b02c77bfcc02b20134 (commit)
       via  1ba05158ebe033d7d0bdfcfef686eae2c9ea0103 (commit)
       via  6f63f118ef15d4c44ed87944735c0cf32153408a (commit)
      from  ec97a06f86f233c36c77e22eb43f38898c1fbdd7 (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit eb4a14ed47a34e03566261b02c77bfcc02b20134
Author: Ludovic Courtès <address@hidden>
Date:   Fri Feb 3 10:51:46 2012 +0100

    Use Gnulib's `regex' module.
    
    This should help with regex portability, as reported in
    <http://bugs.gnu.org/10684> for Darwin 8.11.
    
    * m4/gnulib-cache.m4 (gl_MODULES): Add `regex'.
    
    * configure.ac: Remove header checks for regex.h, rxposix.h, and
      rx/rxposix.h.  Remove check for the `regcomp' function.  Remove
      definition of `HAVE_REGCOMP'.  Define `ENABLE_REGEX'.
    
    * libguile/init.c: Check for `ENABLE_REGEX' instead of `HAVE_REGCOMP'.
    
    * libguile/regex-posix.c: Always include <regex.h>.  Remove #ifdefs for
      rxposix.h and co.

commit 1ba05158ebe033d7d0bdfcfef686eae2c9ea0103
Author: Ludovic Courtès <address@hidden>
Date:   Fri Feb 3 10:30:52 2012 +0100

    tests: Have `getaddrinfo' test work for Darwin 8.
    
    * doc/ref/posix.texi (Network Databases): Update description of
      `EAI_NODATA' to mention that Darwin provides it.
    
    * libguile/net_db.c (scm_getaddrinfo): Likewise.
    
    * test-suite/tests/net-db.test ("getaddrinfo")["wrong service name"]:
      Accept `EAI_NODATA' too.  Reported by David Fang <address@hidden>,
      see <http://bugs.gnu.org/10684>.

commit 6f63f118ef15d4c44ed87944735c0cf32153408a
Author: Ludovic Courtès <address@hidden>
Date:   Fri Feb 3 10:17:12 2012 +0100

    tests: Work around erroneous tr_TR locale in Darwin 8.
    
    * test-suite/tests/i18n.test (under-turkish-utf8-locale-or-unresolved):
      Add exception for Darwin 8.  Reported by David Fang <address@hidden>,
      see <http://bugs.gnu.org/10684>.

-----------------------------------------------------------------------

Summary of changes:
 configure.ac                 |   24 +-
 doc/ref/posix.texi           |   10 +-
 lib/Makefile.am              |  184 ++-
 lib/btowc.c                  |   39 +
 lib/langinfo.in.h            |  177 ++
 lib/mbrtowc.c                |  396 ++++
 lib/mbsinit.c                |   61 +
 lib/mbtowc-impl.h            |   44 +
 lib/mbtowc.c                 |   26 +
 lib/nl_langinfo.c            |  271 +++
 lib/regcomp.c                | 3876 ++++++++++++++++++++++++++++++++++++
 lib/regex.c                  |   72 +
 lib/regex.h                  |  675 +++++++
 lib/regex_internal.c         | 1741 +++++++++++++++++
 lib/regex_internal.h         |  866 +++++++++
 lib/regexec.c                | 4417 ++++++++++++++++++++++++++++++++++++++++++
 lib/strcasecmp.c             |   63 +
 lib/streq.h                  |  176 ++
 lib/strings.in.h             |  123 ++
 lib/strncasecmp.c            |   63 +
 lib/wcrtomb.c                |   53 +
 lib/wctype.in.h              |  499 +++++
 libguile/init.c              |    9 +-
 libguile/net_db.c            |   15 +-
 libguile/regex-posix.c       |   18 +-
 m4/btowc.m4                  |  116 ++
 m4/gnulib-cache.m4           |    3 +-
 m4/gnulib-comp.m4            |   98 +
 m4/langinfo_h.m4             |  105 +
 m4/locale-fr.m4              |  246 +++
 m4/locale-ja.m4              |  136 ++
 m4/locale-zh.m4              |  130 ++
 m4/mbrtowc.m4                |  572 ++++++
 m4/mbsinit.m4                |   51 +
 m4/mbstate_t.m4              |   41 +
 m4/mbtowc.m4                 |   19 +
 m4/nl_langinfo.m4            |   50 +
 m4/regex.m4                  |  223 +++
 m4/strcase.m4                |   45 +
 m4/strings_h.m4              |   52 +
 m4/wcrtomb.m4                |  112 ++
 m4/wctype_h.m4               |  211 ++
 test-suite/tests/i18n.test   |    9 +-
 test-suite/tests/net-db.test |   10 +-
 44 files changed, 16067 insertions(+), 60 deletions(-)
 create mode 100644 lib/btowc.c
 create mode 100644 lib/langinfo.in.h
 create mode 100644 lib/mbrtowc.c
 create mode 100644 lib/mbsinit.c
 create mode 100644 lib/mbtowc-impl.h
 create mode 100644 lib/mbtowc.c
 create mode 100644 lib/nl_langinfo.c
 create mode 100644 lib/regcomp.c
 create mode 100644 lib/regex.c
 create mode 100644 lib/regex.h
 create mode 100644 lib/regex_internal.c
 create mode 100644 lib/regex_internal.h
 create mode 100644 lib/regexec.c
 create mode 100644 lib/strcasecmp.c
 create mode 100644 lib/streq.h
 create mode 100644 lib/strings.in.h
 create mode 100644 lib/strncasecmp.c
 create mode 100644 lib/wcrtomb.c
 create mode 100644 lib/wctype.in.h
 create mode 100644 m4/btowc.m4
 create mode 100644 m4/langinfo_h.m4
 create mode 100644 m4/locale-fr.m4
 create mode 100644 m4/locale-ja.m4
 create mode 100644 m4/locale-zh.m4
 create mode 100644 m4/mbrtowc.m4
 create mode 100644 m4/mbsinit.m4
 create mode 100644 m4/mbstate_t.m4
 create mode 100644 m4/mbtowc.m4
 create mode 100644 m4/nl_langinfo.m4
 create mode 100644 m4/regex.m4
 create mode 100644 m4/strcase.m4
 create mode 100644 m4/strings_h.m4
 create mode 100644 m4/wcrtomb.m4
 create mode 100644 m4/wctype_h.m4

diff --git a/configure.ac b/configure.ac
index ccc5fa5..5ee942c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,7 @@ dnl
 define(GUILE_CONFIGURE_COPYRIGHT,[[
 
 Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
-  2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
+  2007, 2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 
 This file is part of GUILE
 
@@ -656,7 +656,7 @@ AC_SUBST([SCM_I_GSC_HAVE_STRUCT_DIRENT64])
 #   sched.h - missing on MinGW
 #
 AC_CHECK_HEADERS([complex.h fenv.h io.h libc.h limits.h memory.h process.h 
string.h \
-regex.h rxposix.h rx/rxposix.h sys/dir.h sys/ioctl.h sys/select.h \
+sys/dir.h sys/ioctl.h sys/select.h \
 sys/time.h sys/timeb.h sys/times.h sys/stdtypes.h sys/types.h \
 sys/utime.h time.h unistd.h utime.h pwd.h grp.h sys/utsname.h \
 direct.h langinfo.h nl_types.h machine/fpu.h poll.h sched.h])
@@ -1112,24 +1112,8 @@ if test $guile_cv_localtime_cache = yes; then
 fi
 
 if test "$enable_regex" = yes; then
-   if test "$ac_cv_header_regex_h" = yes ||
-      test "$ac_cv_header_rxposix_h" = yes ||
-      test "$ac_cv_header_rx_rxposix_h" = yes; then
-     GUILE_NAMED_CHECK_FUNC(regcomp, norx, [AC_LIBOBJ([regex-posix])],
-     [AC_CHECK_LIB(rx, main)
-      GUILE_NAMED_CHECK_FUNC(regcomp, rx, [AC_LIBOBJ([regex-posix])],
-     [AC_CHECK_LIB(regex, main)
-      GUILE_NAMED_CHECK_FUNC(regcomp, regex, [AC_LIBOBJ([regex-posix])])])]
-     )
-     dnl The following should not be necessary, but for some reason
-     dnl autoheader misses it if we don't include it!
-     if test "$ac_cv_func_regcomp_norx" = yes ||
-        test "$ac_cv_func_regcomp_regex" = yes ||
-        test "$ac_cv_func_regcomp_rx" = yes; then
-       AC_DEFINE([HAVE_REGCOMP], 1,
-         [This is included as part of a workaround for a autoheader bug.])
-     fi
-   fi
+   AC_LIBOBJ([regex-posix])
+   AC_DEFINE([ENABLE_REGEX], 1, [Define when regex support is enabled.])
 fi
 
 AC_REPLACE_FUNCS([strerror memmove mkstemp])
diff --git a/doc/ref/posix.texi b/doc/ref/posix.texi
index 0defc3f..9933495 100644
--- a/doc/ref/posix.texi
+++ b/doc/ref/posix.texi
@@ -1,7 +1,7 @@
 @c -*-texinfo-*-
 @c This is part of the GNU Guile Reference Manual.
address@hidden Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2006, 
2007, 2008, 2009, 2010, 2011
address@hidden   Free Software Foundation, Inc.
address@hidden Copyright (C)  1996, 1997, 2000, 2001, 2002, 2003, 2004, 2006, 
2007,
address@hidden   2008, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
 @c See the file guile.texi for copying conditions.
 
 @node POSIX
@@ -2502,9 +2502,9 @@ Either @var{name} does not resolve for the supplied 
parameters,
 or neither @var{name} nor @var{service} were supplied.
 
 @item EAI_NODATA
-This non-POSIX error code can be returned on GNU systems when a
-request was actually made but returned no data, meaning
-that no address is associated with @var{name}.  Error handling
+This non-POSIX error code can be returned on some systems (GNU
+and Darwin, at least), for example when @var{name} is known
+but requests that were made turned out no data.  Error handling
 code should be prepared to handle it when it is defined.
 
 @item EAI_SERVICE
diff --git a/lib/Makefile.am b/lib/Makefile.am
index a4a9960..17fb5b4 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local 
--lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests 
--aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool 
--macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen 
autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale 
environ extensions flock floor fpieee frexp full-read full-write func gendocs 
getaddrinfo getpeername getsockname getsockopt git-version-gen 
gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf 
inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility 
libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu 
malloca nproc open pipe2 putenv recv recvfrom rename send sendto setenv 
setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat 
trunc verify vsnprintf warnings wchar
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local 
--lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests 
--aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool 
--macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen 
autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale 
environ extensions flock floor fpieee frexp full-read full-write func gendocs 
getaddrinfo getpeername getsockname getsockopt git-version-gen 
gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf 
inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility 
libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu 
malloca nproc open pipe2 putenv recv recvfrom regex rename send sendto setenv 
setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat 
trunc verify vsnprintf warnings wchar
 
 AUTOMAKE_OPTIONS = 1.5 gnits subdir-objects
 
@@ -165,6 +165,15 @@ EXTRA_libgnu_la_SOURCES += bind.c
 
 ## end   gnulib module bind
 
+## begin gnulib module btowc
+
+
+EXTRA_DIST += btowc.c
+
+EXTRA_libgnu_la_SOURCES += btowc.c
+
+## end   gnulib module btowc
+
 ## begin gnulib module byteswap
 
 BUILT_SOURCES += $(BYTESWAP_H)
@@ -755,6 +764,39 @@ EXTRA_libgnu_la_SOURCES += isnan.c isnanl.c
 
 ## end   gnulib module isnanl
 
+## begin gnulib module langinfo
+
+BUILT_SOURCES += langinfo.h
+
+# We need the following in order to create an empty placeholder for
+# <langinfo.h> when the system doesn't have one.
+langinfo.h: langinfo.in.h $(top_builddir)/config.status $(CXXDEFS_H) 
$(WARN_ON_USE_H)
+       $(AM_V_GEN)rm -f address@hidden $@ && \
+       { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+         sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+             -e 's|@''HAVE_LANGINFO_H''@|$(HAVE_LANGINFO_H)|g' \
+             -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+             -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+             -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+             -e 's|@''NEXT_LANGINFO_H''@|$(NEXT_LANGINFO_H)|g' \
+             -e 's/@''GNULIB_NL_LANGINFO''@/$(GNULIB_NL_LANGINFO)/g' \
+             -e 's|@''HAVE_LANGINFO_CODESET''@|$(HAVE_LANGINFO_CODESET)|g' \
+             -e 
's|@''HAVE_LANGINFO_T_FMT_AMPM''@|$(HAVE_LANGINFO_T_FMT_AMPM)|g' \
+             -e 's|@''HAVE_LANGINFO_ERA''@|$(HAVE_LANGINFO_ERA)|g' \
+             -e 's|@''HAVE_LANGINFO_YESEXPR''@|$(HAVE_LANGINFO_YESEXPR)|g' \
+             -e 's|@''HAVE_NL_LANGINFO''@|$(HAVE_NL_LANGINFO)|g' \
+             -e 's|@''REPLACE_NL_LANGINFO''@|$(REPLACE_NL_LANGINFO)|g' \
+             -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+             -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+             < $(srcdir)/langinfo.in.h; \
+       } > address@hidden && \
+       mv address@hidden $@
+MOSTLYCLEANFILES += langinfo.h langinfo.h-t
+
+EXTRA_DIST += langinfo.in.h
+
+## end   gnulib module langinfo
+
 ## begin gnulib module lib-symbol-visibility
 
 # The value of $(CFLAG_VISIBILITY) needs to be added to the CFLAGS for the
@@ -1106,6 +1148,33 @@ EXTRA_DIST += math.in.h
 
 ## end   gnulib module math
 
+## begin gnulib module mbrtowc
+
+
+EXTRA_DIST += mbrtowc.c
+
+EXTRA_libgnu_la_SOURCES += mbrtowc.c
+
+## end   gnulib module mbrtowc
+
+## begin gnulib module mbsinit
+
+
+EXTRA_DIST += mbsinit.c
+
+EXTRA_libgnu_la_SOURCES += mbsinit.c
+
+## end   gnulib module mbsinit
+
+## begin gnulib module mbtowc
+
+
+EXTRA_DIST += mbtowc-impl.h mbtowc.c
+
+EXTRA_libgnu_la_SOURCES += mbtowc.c
+
+## end   gnulib module mbtowc
+
 ## begin gnulib module memchr
 
 
@@ -1198,6 +1267,15 @@ EXTRA_DIST += netinet_in.in.h
 
 ## end   gnulib module netinet_in
 
+## begin gnulib module nl_langinfo
+
+
+EXTRA_DIST += nl_langinfo.c
+
+EXTRA_libgnu_la_SOURCES += nl_langinfo.c
+
+## end   gnulib module nl_langinfo
+
 ## begin gnulib module nproc
 
 libgnu_la_SOURCES += nproc.c
@@ -1282,6 +1360,15 @@ EXTRA_libgnu_la_SOURCES += recvfrom.c
 
 ## end   gnulib module recvfrom
 
+## begin gnulib module regex
+
+
+EXTRA_DIST += regcomp.c regex.c regex.h regex_internal.c regex_internal.h 
regexec.c
+
+EXTRA_libgnu_la_SOURCES += regcomp.c regex.c regex_internal.c regexec.c
+
+## end   gnulib module regex
+
 ## begin gnulib module rename
 
 
@@ -1921,6 +2008,22 @@ EXTRA_DIST += stdlib.in.h
 
 ## end   gnulib module stdlib
 
+## begin gnulib module strcase
+
+
+EXTRA_DIST += strcasecmp.c strncasecmp.c
+
+EXTRA_libgnu_la_SOURCES += strcasecmp.c strncasecmp.c
+
+## end   gnulib module strcase
+
+## begin gnulib module streq
+
+
+EXTRA_DIST += streq.h
+
+## end   gnulib module streq
+
 ## begin gnulib module strftime
 
 libgnu_la_SOURCES += strftime.c
@@ -2040,6 +2143,37 @@ EXTRA_DIST += string.in.h
 
 ## end   gnulib module string
 
+## begin gnulib module strings
+
+BUILT_SOURCES += strings.h
+
+# We need the following in order to create <strings.h> when the system
+# doesn't have one that works with the given compiler.
+strings.h: strings.in.h $(top_builddir)/config.status $(CXXDEFS_H) 
$(WARN_ON_USE_H) $(ARG_NONNULL_H)
+       $(AM_V_GEN)rm -f address@hidden $@ && \
+       { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */' && \
+         sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+             -e 's|@''HAVE_STRINGS_H''@|$(HAVE_STRINGS_H)|g' \
+             -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+             -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+             -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+             -e 's|@''NEXT_STRINGS_H''@|$(NEXT_STRINGS_H)|g' \
+             -e 's|@''GNULIB_FFS''@|$(GNULIB_FFS)|g' \
+             -e 's|@''HAVE_FFS''@|$(HAVE_FFS)|g' \
+             -e 's|@''HAVE_STRCASECMP''@|$(HAVE_STRCASECMP)|g' \
+             -e 's|@''HAVE_DECL_STRNCASECMP''@|$(HAVE_DECL_STRNCASECMP)|g' \
+             -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+             -e '/definition of _GL_ARG_NONNULL/r $(ARG_NONNULL_H)' \
+             -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+             < $(srcdir)/strings.in.h; \
+       } > address@hidden && \
+       mv address@hidden $@
+MOSTLYCLEANFILES += strings.h strings.h-t
+
+EXTRA_DIST += strings.in.h
+
+## end   gnulib module strings
+
 ## begin gnulib module sys_file
 
 BUILT_SOURCES += sys/file.h
@@ -2704,6 +2838,54 @@ EXTRA_DIST += wchar.in.h
 
 ## end   gnulib module wchar
 
+## begin gnulib module wcrtomb
+
+
+EXTRA_DIST += wcrtomb.c
+
+EXTRA_libgnu_la_SOURCES += wcrtomb.c
+
+## end   gnulib module wcrtomb
+
+## begin gnulib module wctype-h
+
+BUILT_SOURCES += wctype.h
+
+# We need the following in order to create <wctype.h> when the system
+# doesn't have one that works with the given compiler.
+wctype.h: wctype.in.h $(top_builddir)/config.status $(CXXDEFS_H) 
$(WARN_ON_USE_H)
+       $(AM_V_GEN)rm -f address@hidden $@ && \
+       { echo '/* DO NOT EDIT! GENERATED AUTOMATICALLY! */'; \
+         sed -e 's|@''GUARD_PREFIX''@|GL|g' \
+             -e 's/@''HAVE_WCTYPE_H''@/$(HAVE_WCTYPE_H)/g' \
+             -e 's|@''INCLUDE_NEXT''@|$(INCLUDE_NEXT)|g' \
+             -e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
+             -e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
+             -e 's|@''NEXT_WCTYPE_H''@|$(NEXT_WCTYPE_H)|g' \
+             -e 's/@''GNULIB_ISWBLANK''@/$(GNULIB_ISWBLANK)/g' \
+             -e 's/@''GNULIB_WCTYPE''@/$(GNULIB_WCTYPE)/g' \
+             -e 's/@''GNULIB_ISWCTYPE''@/$(GNULIB_ISWCTYPE)/g' \
+             -e 's/@''GNULIB_WCTRANS''@/$(GNULIB_WCTRANS)/g' \
+             -e 's/@''GNULIB_TOWCTRANS''@/$(GNULIB_TOWCTRANS)/g' \
+             -e 's/@''HAVE_ISWBLANK''@/$(HAVE_ISWBLANK)/g' \
+             -e 's/@''HAVE_ISWCNTRL''@/$(HAVE_ISWCNTRL)/g' \
+             -e 's/@''HAVE_WCTYPE_T''@/$(HAVE_WCTYPE_T)/g' \
+             -e 's/@''HAVE_WCTRANS_T''@/$(HAVE_WCTRANS_T)/g' \
+             -e 's/@''HAVE_WINT_T''@/$(HAVE_WINT_T)/g' \
+             -e 's/@''REPLACE_ISWBLANK''@/$(REPLACE_ISWBLANK)/g' \
+             -e 's/@''REPLACE_ISWCNTRL''@/$(REPLACE_ISWCNTRL)/g' \
+             -e 's/@''REPLACE_TOWLOWER''@/$(REPLACE_TOWLOWER)/g' \
+             -e '/definitions of _GL_FUNCDECL_RPL/r $(CXXDEFS_H)' \
+             -e '/definition of _GL_WARN_ON_USE/r $(WARN_ON_USE_H)' \
+             < $(srcdir)/wctype.in.h; \
+       } > address@hidden && \
+       mv address@hidden $@
+MOSTLYCLEANFILES += wctype.h wctype.h-t
+
+EXTRA_DIST += wctype.in.h
+
+## end   gnulib module wctype-h
+
 ## begin gnulib module write
 
 
diff --git a/lib/btowc.c b/lib/btowc.c
new file mode 100644
index 0000000..485e995
--- /dev/null
+++ b/lib/btowc.c
@@ -0,0 +1,39 @@
+/* Convert unibyte character to wide character.
+   Copyright (C) 2008, 2010-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+wint_t
+btowc (int c)
+{
+  if (c != EOF)
+    {
+      char buf[1];
+      wchar_t wc;
+
+      buf[0] = c;
+      if (mbtowc (&wc, buf, 1) >= 0)
+        return wc;
+    }
+  return WEOF;
+}
diff --git a/lib/langinfo.in.h b/lib/langinfo.in.h
new file mode 100644
index 0000000..807b245
--- /dev/null
+++ b/lib/langinfo.in.h
@@ -0,0 +1,177 @@
+/* Substitute for and wrapper around <langinfo.h>.
+   Copyright (C) 2009-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/*
+ * POSIX <langinfo.h> for platforms that lack it or have an incomplete one.
+ * <http://www.opengroup.org/onlinepubs/9699919799/basedefs/langinfo.h.html>
+ */
+
+#ifndef address@hidden@_LANGINFO_H
+
+#if __GNUC__ >= 3
address@hidden@
+#endif
address@hidden@
+
+/* The include_next requires a split double-inclusion guard.  */
+#if @HAVE_LANGINFO_H@
+# @INCLUDE_NEXT@ @NEXT_LANGINFO_H@
+#endif
+
+#ifndef address@hidden@_LANGINFO_H
+#define address@hidden@_LANGINFO_H
+
+
+#if address@hidden@
+
+/* A platform that lacks <langinfo.h>.  */
+
+/* Assume that it also lacks <nl_types.h> and the nl_item type.  */
+# if !GNULIB_defined_nl_item
+typedef int nl_item;
+#  define GNULIB_defined_nl_item 1
+# endif
+
+/* nl_langinfo items of the LC_CTYPE category */
+# define CODESET     10000
+/* nl_langinfo items of the LC_NUMERIC category */
+# define RADIXCHAR   10001
+# define THOUSEP     10002
+/* nl_langinfo items of the LC_TIME category */
+# define D_T_FMT     10003
+# define D_FMT       10004
+# define T_FMT       10005
+# define T_FMT_AMPM  10006
+# define AM_STR      10007
+# define PM_STR      10008
+# define DAY_1       10009
+# define DAY_2       (DAY_1 + 1)
+# define DAY_3       (DAY_1 + 2)
+# define DAY_4       (DAY_1 + 3)
+# define DAY_5       (DAY_1 + 4)
+# define DAY_6       (DAY_1 + 5)
+# define DAY_7       (DAY_1 + 6)
+# define ABDAY_1     10016
+# define ABDAY_2     (ABDAY_1 + 1)
+# define ABDAY_3     (ABDAY_1 + 2)
+# define ABDAY_4     (ABDAY_1 + 3)
+# define ABDAY_5     (ABDAY_1 + 4)
+# define ABDAY_6     (ABDAY_1 + 5)
+# define ABDAY_7     (ABDAY_1 + 6)
+# define MON_1       10023
+# define MON_2       (MON_1 + 1)
+# define MON_3       (MON_1 + 2)
+# define MON_4       (MON_1 + 3)
+# define MON_5       (MON_1 + 4)
+# define MON_6       (MON_1 + 5)
+# define MON_7       (MON_1 + 6)
+# define MON_8       (MON_1 + 7)
+# define MON_9       (MON_1 + 8)
+# define MON_10      (MON_1 + 9)
+# define MON_11      (MON_1 + 10)
+# define MON_12      (MON_1 + 11)
+# define ABMON_1     10035
+# define ABMON_2     (ABMON_1 + 1)
+# define ABMON_3     (ABMON_1 + 2)
+# define ABMON_4     (ABMON_1 + 3)
+# define ABMON_5     (ABMON_1 + 4)
+# define ABMON_6     (ABMON_1 + 5)
+# define ABMON_7     (ABMON_1 + 6)
+# define ABMON_8     (ABMON_1 + 7)
+# define ABMON_9     (ABMON_1 + 8)
+# define ABMON_10    (ABMON_1 + 9)
+# define ABMON_11    (ABMON_1 + 10)
+# define ABMON_12    (ABMON_1 + 11)
+# define ERA         10047
+# define ERA_D_FMT   10048
+# define ERA_D_T_FMT 10049
+# define ERA_T_FMT   10050
+# define ALT_DIGITS  10051
+/* nl_langinfo items of the LC_MONETARY category */
+# define CRNCYSTR    10052
+/* nl_langinfo items of the LC_MESSAGES category */
+# define YESEXPR     10053
+# define NOEXPR      10054
+
+#else
+
+/* A platform that has <langinfo.h>.  */
+
+# if address@hidden@
+#  define CODESET     10000
+#  define GNULIB_defined_CODESET 1
+# endif
+
+# if address@hidden@
+#  define T_FMT_AMPM  10006
+#  define GNULIB_defined_T_FMT_AMPM 1
+# endif
+
+# if address@hidden@
+#  define ERA         10047
+#  define ERA_D_FMT   10048
+#  define ERA_D_T_FMT 10049
+#  define ERA_T_FMT   10050
+#  define ALT_DIGITS  10051
+#  define GNULIB_defined_ERA 1
+# endif
+
+# if address@hidden@
+#  define YESEXPR     10053
+#  define NOEXPR      10054
+#  define GNULIB_defined_YESEXPR 1
+# endif
+
+#endif
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+/* Declare overridden functions.  */
+
+
+/* Return a piece of locale dependent information.
+   Note: The difference between nl_langinfo (CODESET) and locale_charset ()
+   is that the latter normalizes the encoding names to GNU conventions.  */
+
+#if @GNULIB_NL_LANGINFO@
+# if @REPLACE_NL_LANGINFO@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef nl_langinfo
+#   define nl_langinfo rpl_nl_langinfo
+#  endif
+_GL_FUNCDECL_RPL (nl_langinfo, char *, (nl_item item));
+_GL_CXXALIAS_RPL (nl_langinfo, char *, (nl_item item));
+# else
+#  if address@hidden@
+_GL_FUNCDECL_SYS (nl_langinfo, char *, (nl_item item));
+#  endif
+_GL_CXXALIAS_SYS (nl_langinfo, char *, (nl_item item));
+# endif
+_GL_CXXALIASWARN (nl_langinfo);
+#elif defined GNULIB_POSIXCHECK
+# undef nl_langinfo
+# if HAVE_RAW_DECL_NL_LANGINFO
+_GL_WARN_ON_USE (nl_langinfo, "nl_langinfo is not portable - "
+                 "use gnulib module nl_langinfo for portability");
+# endif
+#endif
+
+
+#endif /* address@hidden@_LANGINFO_H */
+#endif /* address@hidden@_LANGINFO_H */
diff --git a/lib/mbrtowc.c b/lib/mbrtowc.c
new file mode 100644
index 0000000..05fb148
--- /dev/null
+++ b/lib/mbrtowc.c
@@ -0,0 +1,396 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 1999-2002, 2005-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#if GNULIB_defined_mbstate_t
+/* Implement mbrtowc() on top of mbtowc().  */
+
+# include <errno.h>
+# include <stdlib.h>
+
+# include "localcharset.h"
+# include "streq.h"
+# include "verify.h"
+
+
+verify (sizeof (mbstate_t) >= 4);
+
+static char internal_state[4];
+
+size_t
+mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
+{
+  char *pstate = (char *)ps;
+
+  if (s == NULL)
+    {
+      pwc = NULL;
+      s = "";
+      n = 1;
+    }
+
+  if (n == 0)
+    return (size_t)(-2);
+
+  /* Here n > 0.  */
+
+  if (pstate == NULL)
+    pstate = internal_state;
+
+  {
+    size_t nstate = pstate[0];
+    char buf[4];
+    const char *p;
+    size_t m;
+
+    switch (nstate)
+      {
+      case 0:
+        p = s;
+        m = n;
+        break;
+      case 3:
+        buf[2] = pstate[3];
+        /*FALLTHROUGH*/
+      case 2:
+        buf[1] = pstate[2];
+        /*FALLTHROUGH*/
+      case 1:
+        buf[0] = pstate[1];
+        p = buf;
+        m = nstate;
+        buf[m++] = s[0];
+        if (n >= 2 && m < 4)
+          {
+            buf[m++] = s[1];
+            if (n >= 3 && m < 4)
+              buf[m++] = s[2];
+          }
+        break;
+      default:
+        errno = EINVAL;
+        return (size_t)(-1);
+      }
+
+    /* Here m > 0.  */
+
+# if __GLIBC__ || defined __UCLIBC__
+    /* Work around bug <http://sourceware.org/bugzilla/show_bug.cgi?id=9674> */
+    mbtowc (NULL, NULL, 0);
+# endif
+    {
+      int res = mbtowc (pwc, p, m);
+
+      if (res >= 0)
+        {
+          if (pwc != NULL && ((*pwc == 0) != (res == 0)))
+            abort ();
+          if (nstate >= (res > 0 ? res : 1))
+            abort ();
+          res -= nstate;
+          pstate[0] = 0;
+          return res;
+        }
+
+      /* mbtowc does not distinguish between invalid and incomplete multibyte
+         sequences.  But mbrtowc needs to make this distinction.
+         There are two possible approaches:
+           - Use iconv() and its return value.
+           - Use built-in knowledge about the possible encodings.
+         Given the low quality of implementation of iconv() on the systems that
+         lack mbrtowc(), we use the second approach.
+         The possible encodings are:
+           - 8-bit encodings,
+           - EUC-JP, EUC-KR, GB2312, EUC-TW, BIG5, GB18030, SJIS,
+           - UTF-8.
+         Use specialized code for each.  */
+      if (m >= 4 || m >= MB_CUR_MAX)
+        goto invalid;
+      /* Here MB_CUR_MAX > 1 and 0 < m < 4.  */
+      {
+        const char *encoding = locale_charset ();
+
+        if (STREQ (encoding, "UTF-8", 'U', 'T', 'F', '-', '8', 0, 0, 0, 0))
+          {
+            /* Cf. unistr/u8-mblen.c.  */
+            unsigned char c = (unsigned char) p[0];
+
+            if (c >= 0xc2)
+              {
+                if (c < 0xe0)
+                  {
+                    if (m == 1)
+                      goto incomplete;
+                  }
+                else if (c < 0xf0)
+                  {
+                    if (m == 1)
+                      goto incomplete;
+                    if (m == 2)
+                      {
+                        unsigned char c2 = (unsigned char) p[1];
+
+                        if ((c2 ^ 0x80) < 0x40
+                            && (c >= 0xe1 || c2 >= 0xa0)
+                            && (c != 0xed || c2 < 0xa0))
+                          goto incomplete;
+                      }
+                  }
+                else if (c <= 0xf4)
+                  {
+                    if (m == 1)
+                      goto incomplete;
+                    else /* m == 2 || m == 3 */
+                      {
+                        unsigned char c2 = (unsigned char) p[1];
+
+                        if ((c2 ^ 0x80) < 0x40
+                            && (c >= 0xf1 || c2 >= 0x90)
+                            && (c < 0xf4 || (c == 0xf4 && c2 < 0x90)))
+                          {
+                            if (m == 2)
+                              goto incomplete;
+                            else /* m == 3 */
+                              {
+                                unsigned char c3 = (unsigned char) p[2];
+
+                                if ((c3 ^ 0x80) < 0x40)
+                                  goto incomplete;
+                              }
+                          }
+                      }
+                  }
+              }
+            goto invalid;
+          }
+
+        /* As a reference for this code, you can use the GNU libiconv
+           implementation.  Look for uses of the RET_TOOFEW macro.  */
+
+        if (STREQ (encoding, "EUC-JP", 'E', 'U', 'C', '-', 'J', 'P', 0, 0, 0))
+          {
+            if (m == 1)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if ((c >= 0xa1 && c < 0xff) || c == 0x8e || c == 0x8f)
+                  goto incomplete;
+              }
+            if (m == 2)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if (c == 0x8f)
+                  {
+                    unsigned char c2 = (unsigned char) p[1];
+
+                    if (c2 >= 0xa1 && c2 < 0xff)
+                      goto incomplete;
+                  }
+              }
+            goto invalid;
+          }
+        if (STREQ (encoding, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
+            || STREQ (encoding, "GB2312", 'G', 'B', '2', '3', '1', '2', 0, 0, 
0)
+            || STREQ (encoding, "BIG5", 'B', 'I', 'G', '5', 0, 0, 0, 0, 0))
+          {
+            if (m == 1)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if (c >= 0xa1 && c < 0xff)
+                  goto incomplete;
+              }
+            goto invalid;
+          }
+        if (STREQ (encoding, "EUC-TW", 'E', 'U', 'C', '-', 'T', 'W', 0, 0, 0))
+          {
+            if (m == 1)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if ((c >= 0xa1 && c < 0xff) || c == 0x8e)
+                  goto incomplete;
+              }
+            else /* m == 2 || m == 3 */
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if (c == 0x8e)
+                  goto incomplete;
+              }
+            goto invalid;
+          }
+        if (STREQ (encoding, "GB18030", 'G', 'B', '1', '8', '0', '3', '0', 0, 
0))
+          {
+            if (m == 1)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if ((c >= 0x90 && c <= 0xe3) || (c >= 0xf8 && c <= 0xfe))
+                  goto incomplete;
+              }
+            else /* m == 2 || m == 3 */
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if (c >= 0x90 && c <= 0xe3)
+                  {
+                    unsigned char c2 = (unsigned char) p[1];
+
+                    if (c2 >= 0x30 && c2 <= 0x39)
+                      {
+                        if (m == 2)
+                          goto incomplete;
+                        else /* m == 3 */
+                          {
+                            unsigned char c3 = (unsigned char) p[2];
+
+                            if (c3 >= 0x81 && c3 <= 0xfe)
+                              goto incomplete;
+                          }
+                      }
+                  }
+              }
+            goto invalid;
+          }
+        if (STREQ (encoding, "SJIS", 'S', 'J', 'I', 'S', 0, 0, 0, 0, 0))
+          {
+            if (m == 1)
+              {
+                unsigned char c = (unsigned char) p[0];
+
+                if ((c >= 0x81 && c <= 0x9f) || (c >= 0xe0 && c <= 0xea)
+                    || (c >= 0xf0 && c <= 0xf9))
+                  goto incomplete;
+              }
+            goto invalid;
+          }
+
+        /* An unknown multibyte encoding.  */
+        goto incomplete;
+      }
+
+     incomplete:
+      {
+        size_t k = nstate;
+        /* Here 0 <= k < m < 4.  */
+        pstate[++k] = s[0];
+        if (k < m)
+          {
+            pstate[++k] = s[1];
+            if (k < m)
+              pstate[++k] = s[2];
+          }
+        if (k != m)
+          abort ();
+      }
+      pstate[0] = m;
+      return (size_t)(-2);
+
+     invalid:
+      errno = EILSEQ;
+      /* The conversion state is undefined, says POSIX.  */
+      return (size_t)(-1);
+    }
+  }
+}
+
+#else
+/* Override the system's mbrtowc() function.  */
+
+# undef mbrtowc
+
+size_t
+rpl_mbrtowc (wchar_t *pwc, const char *s, size_t n, mbstate_t *ps)
+{
+# if MBRTOWC_NULL_ARG2_BUG || MBRTOWC_RETVAL_BUG
+  if (s == NULL)
+    {
+      pwc = NULL;
+      s = "";
+      n = 1;
+    }
+# endif
+
+# if MBRTOWC_RETVAL_BUG
+  {
+    static mbstate_t internal_state;
+
+    /* Override mbrtowc's internal state.  We cannot call mbsinit() on the
+       hidden internal state, but we can call it on our variable.  */
+    if (ps == NULL)
+      ps = &internal_state;
+
+    if (!mbsinit (ps))
+      {
+        /* Parse the rest of the multibyte character byte for byte.  */
+        size_t count = 0;
+        for (; n > 0; s++, n--)
+          {
+            wchar_t wc;
+            size_t ret = mbrtowc (&wc, s, 1, ps);
+
+            if (ret == (size_t)(-1))
+              return (size_t)(-1);
+            count++;
+            if (ret != (size_t)(-2))
+              {
+                /* The multibyte character has been completed.  */
+                if (pwc != NULL)
+                  *pwc = wc;
+                return (wc == 0 ? 0 : count);
+              }
+          }
+        return (size_t)(-2);
+      }
+  }
+# endif
+
+# if MBRTOWC_NUL_RETVAL_BUG
+  {
+    wchar_t wc;
+    size_t ret = mbrtowc (&wc, s, n, ps);
+
+    if (ret != (size_t)(-1) && ret != (size_t)(-2))
+      {
+        if (pwc != NULL)
+          *pwc = wc;
+        if (wc == 0)
+          ret = 0;
+      }
+    return ret;
+  }
+# else
+  {
+#   if MBRTOWC_NULL_ARG1_BUG
+    wchar_t dummy;
+
+    if (pwc == NULL)
+      pwc = &dummy;
+#   endif
+
+    return mbrtowc (pwc, s, n, ps);
+  }
+# endif
+}
+
+#endif
diff --git a/lib/mbsinit.c b/lib/mbsinit.c
new file mode 100644
index 0000000..79278d4
--- /dev/null
+++ b/lib/mbsinit.c
@@ -0,0 +1,61 @@
+/* Test for initial conversion state.
+   Copyright (C) 2008-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#include "verify.h"
+
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+
+/* On native Windows, 'mbstate_t' is defined as 'int'.  */
+
+int
+mbsinit (const mbstate_t *ps)
+{
+  return ps == NULL || *ps == 0;
+}
+
+#else
+
+/* Platforms that lack mbsinit() also lack mbrlen(), mbrtowc(), mbsrtowcs()
+   and wcrtomb(), wcsrtombs().
+   We assume that
+     - sizeof (mbstate_t) >= 4,
+     - only stateless encodings are supported (such as UTF-8 and EUC-JP, but
+       not ISO-2022 variants),
+     - for each encoding, the number of bytes for a wide character is <= 4.
+       (This maximum is attained for UTF-8, GB18030, EUC-TW.)
+   We define the meaning of mbstate_t as follows:
+     - In mb -> wc direction, mbstate_t's first byte contains the number of
+       buffered bytes (in the range 0..3), followed by up to 3 buffered bytes.
+     - In wc -> mb direction, mbstate_t contains no information. In other
+       words, it is always in the initial state.  */
+
+verify (sizeof (mbstate_t) >= 4);
+
+int
+mbsinit (const mbstate_t *ps)
+{
+  const char *pstate = (const char *)ps;
+
+  return pstate == NULL || pstate[0] == 0;
+}
+
+#endif
diff --git a/lib/mbtowc-impl.h b/lib/mbtowc-impl.h
new file mode 100644
index 0000000..3183f91
--- /dev/null
+++ b/lib/mbtowc-impl.h
@@ -0,0 +1,44 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 2011-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2011.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* We don't need a static internal state, because the encoding is not state
+   dependent, and when mbrtowc returns (size_t)(-2). we throw the result
+   away. */
+
+int
+mbtowc (wchar_t *pwc, const char *s, size_t n)
+{
+  if (s == NULL)
+    return 0;
+  else
+    {
+      mbstate_t state;
+      wchar_t wc;
+      size_t result;
+
+      memset (&state, 0, sizeof (mbstate_t));
+      result = mbrtowc (&wc, s, n, &state);
+      if (result == (size_t)-1 || result == (size_t)-2)
+        {
+          errno = EILSEQ;
+          return -1;
+        }
+      if (pwc != NULL)
+        *pwc = wc;
+      return (wc == 0 ? 0 : result);
+    }
+}
diff --git a/lib/mbtowc.c b/lib/mbtowc.c
new file mode 100644
index 0000000..e48b2f2
--- /dev/null
+++ b/lib/mbtowc.c
@@ -0,0 +1,26 @@
+/* Convert multibyte character to wide character.
+   Copyright (C) 2011-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2011.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+#include <stdlib.h>
+
+#include <errno.h>
+#include <string.h>
+#include <wchar.h>
+
+#include "mbtowc-impl.h"
diff --git a/lib/nl_langinfo.c b/lib/nl_langinfo.c
new file mode 100644
index 0000000..4b9bdbe
--- /dev/null
+++ b/lib/nl_langinfo.c
@@ -0,0 +1,271 @@
+/* nl_langinfo() replacement: query locale dependent information.
+
+   Copyright (C) 2007-2012 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <langinfo.h>
+
+#if REPLACE_NL_LANGINFO
+
+/* Override nl_langinfo with support for added nl_item values.  */
+
+# include <locale.h>
+# include <string.h>
+
+# undef nl_langinfo
+
+char *
+rpl_nl_langinfo (nl_item item)
+{
+  switch (item)
+    {
+# if GNULIB_defined_CODESET
+    case CODESET:
+      {
+        const char *locale;
+        static char buf[2 + 10 + 1];
+
+        locale = setlocale (LC_CTYPE, NULL);
+        if (locale != NULL && locale[0] != '\0')
+          {
+            /* If the locale name contains an encoding after the dot, return
+               it.  */
+            const char *dot = strchr (locale, '.');
+
+            if (dot != NULL)
+              {
+                const char *modifier;
+
+                dot++;
+                /* Look for the possible @... trailer and remove it, if any.  
*/
+                modifier = strchr (dot, '@');
+                if (modifier == NULL)
+                  return dot;
+                if (modifier - dot < sizeof (buf))
+                  {
+                    memcpy (buf, dot, modifier - dot);
+                    buf [modifier - dot] = '\0';
+                    return buf;
+                  }
+              }
+          }
+        return "";
+      }
+# endif
+# if GNULIB_defined_T_FMT_AMPM
+    case T_FMT_AMPM:
+      return "%I:%M:%S %p";
+# endif
+# if GNULIB_defined_ERA
+    case ERA:
+      /* The format is not standardized.  In glibc it is a sequence of strings
+         of the form "direction:offset:start_date:end_date:era_name:era_format"
+         with an empty string at the end.  */
+      return "";
+    case ERA_D_FMT:
+      /* The %Ex conversion in strftime behaves like %x if the locale does not
+         have an alternative time format.  */
+      item = D_FMT;
+      break;
+    case ERA_D_T_FMT:
+      /* The %Ec conversion in strftime behaves like %c if the locale does not
+         have an alternative time format.  */
+      item = D_T_FMT;
+      break;
+    case ERA_T_FMT:
+      /* The %EX conversion in strftime behaves like %X if the locale does not
+         have an alternative time format.  */
+      item = T_FMT;
+      break;
+    case ALT_DIGITS:
+      /* The format is not standardized.  In glibc it is a sequence of 10
+         strings, appended in memory.  */
+      return "\0\0\0\0\0\0\0\0\0\0";
+# endif
+# if GNULIB_defined_YESEXPR || !FUNC_NL_LANGINFO_YESEXPR_WORKS
+    case YESEXPR:
+      return "^[yY]";
+    case NOEXPR:
+      return "^[nN]";
+# endif
+    default:
+      break;
+    }
+  return nl_langinfo (item);
+}
+
+#else
+
+/* Provide nl_langinfo from scratch.  */
+
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+
+/* Native Windows platforms.  */
+
+#  define WIN32_LEAN_AND_MEAN  /* avoid including junk */
+#  include <windows.h>
+
+#  include <stdio.h>
+
+# else
+
+/* An old Unix platform without locales, such as Linux libc5 or BeOS.  */
+
+# endif
+
+# include <locale.h>
+
+char *
+nl_langinfo (nl_item item)
+{
+  switch (item)
+    {
+    /* nl_langinfo items of the LC_CTYPE category */
+    case CODESET:
+# if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+      {
+        static char buf[2 + 10 + 1];
+
+        /* The Windows API has a function returning the locale's codepage as
+           a number.  */
+        sprintf (buf, "CP%u", GetACP ());
+        return buf;
+      }
+# elif defined __BEOS__
+      return "UTF-8";
+# else
+      return "ISO-8859-1";
+# endif
+    /* nl_langinfo items of the LC_NUMERIC category */
+    case RADIXCHAR:
+      return localeconv () ->decimal_point;
+    case THOUSEP:
+      return localeconv () ->thousands_sep;
+    /* nl_langinfo items of the LC_TIME category.
+       TODO: Really use the locale.  */
+    case D_T_FMT:
+    case ERA_D_T_FMT:
+      return "%a %b %e %H:%M:%S %Y";
+    case D_FMT:
+    case ERA_D_FMT:
+      return "%m/%d/%y";
+    case T_FMT:
+    case ERA_T_FMT:
+      return "%H:%M:%S";
+    case T_FMT_AMPM:
+      return "%I:%M:%S %p";
+    case AM_STR:
+      return "AM";
+    case PM_STR:
+      return "PM";
+    case DAY_1:
+      return "Sunday";
+    case DAY_2:
+      return "Monday";
+    case DAY_3:
+      return "Tuesday";
+    case DAY_4:
+      return "Wednesday";
+    case DAY_5:
+      return "Thursday";
+    case DAY_6:
+      return "Friday";
+    case DAY_7:
+      return "Saturday";
+    case ABDAY_1:
+      return "Sun";
+    case ABDAY_2:
+      return "Mon";
+    case ABDAY_3:
+      return "Tue";
+    case ABDAY_4:
+      return "Wed";
+    case ABDAY_5:
+      return "Thu";
+    case ABDAY_6:
+      return "Fri";
+    case ABDAY_7:
+      return "Sat";
+    case MON_1:
+      return "January";
+    case MON_2:
+      return "February";
+    case MON_3:
+      return "March";
+    case MON_4:
+      return "April";
+    case MON_5:
+      return "May";
+    case MON_6:
+      return "June";
+    case MON_7:
+      return "July";
+    case MON_8:
+      return "August";
+    case MON_9:
+      return "September";
+    case MON_10:
+      return "October";
+    case MON_11:
+      return "November";
+    case MON_12:
+      return "December";
+    case ABMON_1:
+      return "Jan";
+    case ABMON_2:
+      return "Feb";
+    case ABMON_3:
+      return "Mar";
+    case ABMON_4:
+      return "Apr";
+    case ABMON_5:
+      return "May";
+    case ABMON_6:
+      return "Jun";
+    case ABMON_7:
+      return "Jul";
+    case ABMON_8:
+      return "Aug";
+    case ABMON_9:
+      return "Sep";
+    case ABMON_10:
+      return "Oct";
+    case ABMON_11:
+      return "Nov";
+    case ABMON_12:
+      return "Dec";
+    case ERA:
+      return "";
+    case ALT_DIGITS:
+      return "\0\0\0\0\0\0\0\0\0\0";
+    /* nl_langinfo items of the LC_MONETARY category
+       TODO: Really use the locale. */
+    case CRNCYSTR:
+      return "-";
+    /* nl_langinfo items of the LC_MESSAGES category
+       TODO: Really use the locale. */
+    case YESEXPR:
+      return "^[yY]";
+    case NOEXPR:
+      return "^[nN]";
+    default:
+      return "";
+    }
+}
+
+#endif
diff --git a/lib/regcomp.c b/lib/regcomp.c
new file mode 100644
index 0000000..ac13307
--- /dev/null
+++ b/lib/regcomp.c
@@ -0,0 +1,3876 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <address@hidden>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
+                                         size_t length, reg_syntax_t syntax);
+static void re_compile_fastmap_iter (regex_t *bufp,
+                                    const re_dfastate_t *init_state,
+                                    char *fastmap);
+static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
+#ifdef RE_ENABLE_I18N
+static void free_charset (re_charset_t *cset);
+#endif /* RE_ENABLE_I18N */
+static void free_workarea_compile (regex_t *preg);
+static reg_errcode_t create_initial_state (re_dfa_t *dfa);
+#ifdef RE_ENABLE_I18N
+static void optimize_utf8 (re_dfa_t *dfa);
+#endif
+static reg_errcode_t analyze (regex_t *preg);
+static reg_errcode_t preorder (bin_tree_t *root,
+                              reg_errcode_t (fn (void *, bin_tree_t *)),
+                              void *extra);
+static reg_errcode_t postorder (bin_tree_t *root,
+                               reg_errcode_t (fn (void *, bin_tree_t *)),
+                               void *extra);
+static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
+static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
+static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
+                                bin_tree_t *node);
+static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
+static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
+static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
+static Idx duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int 
constraint);
+static Idx search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
+                                  unsigned int constraint);
+static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
+static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
+                                        Idx node, bool root);
+static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
+static Idx fetch_number (re_string_t *input, re_token_t *token,
+                        reg_syntax_t syntax);
+static int peek_token (re_token_t *token, re_string_t *input,
+                       reg_syntax_t syntax) internal_function;
+static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
+                         reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
+                                 re_token_t *token, reg_syntax_t syntax,
+                                 Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg,
+                                re_token_t *token, reg_syntax_t syntax,
+                                Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg,
+                                    re_token_t *token, reg_syntax_t syntax,
+                                    Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg,
+                                 re_token_t *token, reg_syntax_t syntax,
+                                 Idx nest, reg_errcode_t *err);
+static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp,
+                                re_dfa_t *dfa, re_token_t *token,
+                                reg_syntax_t syntax, reg_errcode_t *err);
+static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa,
+                                     re_token_t *token, reg_syntax_t syntax,
+                                     reg_errcode_t *err);
+static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
+                                           re_string_t *regexp,
+                                           re_token_t *token, int token_len,
+                                           re_dfa_t *dfa,
+                                           reg_syntax_t syntax,
+                                           bool accept_hyphen);
+static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
+                                         re_string_t *regexp,
+                                         re_token_t *token);
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+                                       re_charset_t *mbcset,
+                                       Idx *equiv_class_alloc,
+                                       const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+                                     bitset_t sbcset,
+                                     re_charset_t *mbcset,
+                                     Idx *char_class_alloc,
+                                     const unsigned char *class_name,
+                                     reg_syntax_t syntax);
+#else  /* not RE_ENABLE_I18N */
+static reg_errcode_t build_equiv_class (bitset_t sbcset,
+                                       const unsigned char *name);
+static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
+                                     bitset_t sbcset,
+                                     const unsigned char *class_name,
+                                     reg_syntax_t syntax);
+#endif /* not RE_ENABLE_I18N */
+static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
+                                      RE_TRANSLATE_TYPE trans,
+                                      const unsigned char *class_name,
+                                      const unsigned char *extra,
+                                      bool non_match, reg_errcode_t *err);
+static bin_tree_t *create_tree (re_dfa_t *dfa,
+                               bin_tree_t *left, bin_tree_t *right,
+                               re_token_type_t type);
+static bin_tree_t *create_token_tree (re_dfa_t *dfa,
+                                     bin_tree_t *left, bin_tree_t *right,
+                                     const re_token_t *token);
+static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
+static void free_token (re_token_t *node);
+static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
+static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);
+
+/* This table gives an error message for each of the error codes listed
+   in regex.h.  Obviously the order here has to be same as there.
+   POSIX doesn't require that we do anything for REG_NOERROR,
+   but why not be nice?  */
+
+static const char __re_error_msgid[] =
+  {
+#define REG_NOERROR_IDX        0
+    gettext_noop ("Success")   /* REG_NOERROR */
+    "\0"
+#define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
+    gettext_noop ("No match")  /* REG_NOMATCH */
+    "\0"
+#define REG_BADPAT_IDX (REG_NOMATCH_IDX + sizeof "No match")
+    gettext_noop ("Invalid regular expression") /* REG_BADPAT */
+    "\0"
+#define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
+    gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
+    "\0"
+#define REG_ECTYPE_IDX (REG_ECOLLATE_IDX + sizeof "Invalid collation 
character")
+    gettext_noop ("Invalid character class name") /* REG_ECTYPE */
+    "\0"
+#define REG_EESCAPE_IDX        (REG_ECTYPE_IDX + sizeof "Invalid character 
class name")
+    gettext_noop ("Trailing backslash") /* REG_EESCAPE */
+    "\0"
+#define REG_ESUBREG_IDX        (REG_EESCAPE_IDX + sizeof "Trailing backslash")
+    gettext_noop ("Invalid back reference") /* REG_ESUBREG */
+    "\0"
+#define REG_EBRACK_IDX (REG_ESUBREG_IDX + sizeof "Invalid back reference")
+    gettext_noop ("Unmatched [ or [^") /* REG_EBRACK */
+    "\0"
+#define REG_EPAREN_IDX (REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
+    gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
+    "\0"
+#define REG_EBRACE_IDX (REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
+    gettext_noop ("Unmatched \\{") /* REG_EBRACE */
+    "\0"
+#define REG_BADBR_IDX  (REG_EBRACE_IDX + sizeof "Unmatched \\{")
+    gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
+    "\0"
+#define REG_ERANGE_IDX (REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
+    gettext_noop ("Invalid range end") /* REG_ERANGE */
+    "\0"
+#define REG_ESPACE_IDX (REG_ERANGE_IDX + sizeof "Invalid range end")
+    gettext_noop ("Memory exhausted") /* REG_ESPACE */
+    "\0"
+#define REG_BADRPT_IDX (REG_ESPACE_IDX + sizeof "Memory exhausted")
+    gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
+    "\0"
+#define REG_EEND_IDX   (REG_BADRPT_IDX + sizeof "Invalid preceding regular 
expression")
+    gettext_noop ("Premature end of regular expression") /* REG_EEND */
+    "\0"
+#define REG_ESIZE_IDX  (REG_EEND_IDX + sizeof "Premature end of regular 
expression")
+    gettext_noop ("Regular expression too big") /* REG_ESIZE */
+    "\0"
+#define REG_ERPAREN_IDX        (REG_ESIZE_IDX + sizeof "Regular expression too 
big")
+    gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
+  };
+
+static const size_t __re_error_msgid_idx[] =
+  {
+    REG_NOERROR_IDX,
+    REG_NOMATCH_IDX,
+    REG_BADPAT_IDX,
+    REG_ECOLLATE_IDX,
+    REG_ECTYPE_IDX,
+    REG_EESCAPE_IDX,
+    REG_ESUBREG_IDX,
+    REG_EBRACK_IDX,
+    REG_EPAREN_IDX,
+    REG_EBRACE_IDX,
+    REG_BADBR_IDX,
+    REG_ERANGE_IDX,
+    REG_ESPACE_IDX,
+    REG_BADRPT_IDX,
+    REG_EEND_IDX,
+    REG_ESIZE_IDX,
+    REG_ERPAREN_IDX
+  };
+
+/* Entry points for GNU code.  */
+
+/* re_compile_pattern is the GNU regular expression compiler: it
+   compiles PATTERN (of length LENGTH) and puts the result in BUFP.
+   Returns 0 if the pattern was valid, otherwise an error string.
+
+   Assumes the 'allocated' (and perhaps 'buffer') and 'translate' fields
+   are set in BUFP on entry.  */
+
+#ifdef _LIBC
+const char *
+re_compile_pattern (pattern, length, bufp)
+    const char *pattern;
+    size_t length;
+    struct re_pattern_buffer *bufp;
+#else /* size_t might promote */
+const char *
+re_compile_pattern (const char *pattern, size_t length,
+                   struct re_pattern_buffer *bufp)
+#endif
+{
+  reg_errcode_t ret;
+
+  /* And GNU code determines whether or not to get register information
+     by passing null for the REGS argument to re_match, etc., not by
+     setting no_sub, unless RE_NO_SUB is set.  */
+  bufp->no_sub = !!(re_syntax_options & RE_NO_SUB);
+
+  /* Match anchors at newline.  */
+  bufp->newline_anchor = 1;
+
+  ret = re_compile_internal (bufp, pattern, length, re_syntax_options);
+
+  if (!ret)
+    return NULL;
+  return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+#ifdef _LIBC
+weak_alias (__re_compile_pattern, re_compile_pattern)
+#endif
+
+/* Set by 're_set_syntax' to the current regexp syntax to recognize.  Can
+   also be assigned to arbitrarily: each pattern buffer stores its own
+   syntax, so it can be changed between regex compilations.  */
+/* This has no initializer because initialized variables in Emacs
+   become read-only after dumping.  */
+reg_syntax_t re_syntax_options;
+
+
+/* Specify the precise syntax of regexps for compilation.  This provides
+   for compatibility for various utilities which historically have
+   different, incompatible syntaxes.
+
+   The argument SYNTAX is a bit mask comprised of the various bits
+   defined in regex.h.  We return the old syntax.  */
+
+reg_syntax_t
+re_set_syntax (syntax)
+    reg_syntax_t syntax;
+{
+  reg_syntax_t ret = re_syntax_options;
+
+  re_syntax_options = syntax;
+  return ret;
+}
+#ifdef _LIBC
+weak_alias (__re_set_syntax, re_set_syntax)
+#endif
+
+int
+re_compile_fastmap (bufp)
+    struct re_pattern_buffer *bufp;
+{
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  char *fastmap = bufp->fastmap;
+
+  memset (fastmap, '\0', sizeof (char) * SBC_MAX);
+  re_compile_fastmap_iter (bufp, dfa->init_state, fastmap);
+  if (dfa->init_state != dfa->init_state_word)
+    re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap);
+  if (dfa->init_state != dfa->init_state_nl)
+    re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap);
+  if (dfa->init_state != dfa->init_state_begbuf)
+    re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap);
+  bufp->fastmap_accurate = 1;
+  return 0;
+}
+#ifdef _LIBC
+weak_alias (__re_compile_fastmap, re_compile_fastmap)
+#endif
+
+static inline void
+__attribute ((always_inline))
+re_set_fastmap (char *fastmap, bool icase, int ch)
+{
+  fastmap[ch] = 1;
+  if (icase)
+    fastmap[tolower (ch)] = 1;
+}
+
+/* Helper function for re_compile_fastmap.
+   Compile fastmap for the initial_state INIT_STATE.  */
+
+static void
+re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
+                        char *fastmap)
+{
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+  Idx node_cnt;
+  bool icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE));
+  for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt)
+    {
+      Idx node = init_state->nodes.elems[node_cnt];
+      re_token_type_t type = dfa->nodes[node].type;
+
+      if (type == CHARACTER)
+       {
+         re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c);
+#ifdef RE_ENABLE_I18N
+         if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+           {
+             unsigned char buf[MB_LEN_MAX];
+             unsigned char *p;
+             wchar_t wc;
+             mbstate_t state;
+
+             p = buf;
+             *p++ = dfa->nodes[node].opr.c;
+             while (++node < dfa->nodes_len
+                    && dfa->nodes[node].type == CHARACTER
+                    && dfa->nodes[node].mb_partial)
+               *p++ = dfa->nodes[node].opr.c;
+             memset (&state, '\0', sizeof (state));
+             if (__mbrtowc (&wc, (const char *) buf, p - buf,
+                            &state) == p - buf
+                 && (__wcrtomb ((char *) buf, towlower (wc), &state)
+                     != (size_t) -1))
+               re_set_fastmap (fastmap, false, buf[0]);
+           }
+#endif
+       }
+      else if (type == SIMPLE_BRACKET)
+       {
+         int i, ch;
+         for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+           {
+             int j;
+             bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
+             for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+               if (w & ((bitset_word_t) 1 << j))
+                 re_set_fastmap (fastmap, icase, ch);
+           }
+       }
+#ifdef RE_ENABLE_I18N
+      else if (type == COMPLEX_BRACKET)
+       {
+         re_charset_t *cset = dfa->nodes[node].opr.mbcset;
+         Idx i;
+
+# ifdef _LIBC
+         /* See if we have to try all bytes which start multiple collation
+            elements.
+            e.g. In da_DK, we want to catch 'a' since "aa" is a valid
+                 collation element, and don't catch 'b' since 'b' is
+                 the only collation element which starts from 'b' (and
+                 it is caught by SIMPLE_BRACKET).  */
+             if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0
+                 && (cset->ncoll_syms || cset->nranges))
+               {
+                 const int32_t *table = (const int32_t *)
+                   _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+                 for (i = 0; i < SBC_MAX; ++i)
+                   if (table[i] < 0)
+                     re_set_fastmap (fastmap, icase, i);
+               }
+# endif /* _LIBC */
+
+         /* See if we have to start the match at all multibyte characters,
+            i.e. where we would not find an invalid sequence.  This only
+            applies to multibyte character sets; for single byte character
+            sets, the SIMPLE_BRACKET again suffices.  */
+         if (dfa->mb_cur_max > 1
+             && (cset->nchar_classes || cset->non_match || cset->nranges
+# ifdef _LIBC
+                 || cset->nequiv_classes
+# endif /* _LIBC */
+                ))
+           {
+             unsigned char c = 0;
+             do
+               {
+                 mbstate_t mbs;
+                 memset (&mbs, 0, sizeof (mbs));
+                 if (__mbrtowc (NULL, (char *) &c, 1, &mbs) == (size_t) -2)
+                   re_set_fastmap (fastmap, false, (int) c);
+               }
+             while (++c != 0);
+           }
+
+         else
+           {
+             /* ... Else catch all bytes which can start the mbchars.  */
+             for (i = 0; i < cset->nmbchars; ++i)
+               {
+                 char buf[256];
+                 mbstate_t state;
+                 memset (&state, '\0', sizeof (state));
+                 if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
+                   re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
+                 if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
+                   {
+                     if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state)
+                         != (size_t) -1)
+                       re_set_fastmap (fastmap, false, *(unsigned char *) buf);
+                   }
+               }
+           }
+       }
+#endif /* RE_ENABLE_I18N */
+      else if (type == OP_PERIOD
+#ifdef RE_ENABLE_I18N
+              || type == OP_UTF8_PERIOD
+#endif /* RE_ENABLE_I18N */
+              || type == END_OF_RE)
+       {
+         memset (fastmap, '\1', sizeof (char) * SBC_MAX);
+         if (type == END_OF_RE)
+           bufp->can_be_null = 1;
+         return;
+       }
+    }
+}
+
+/* Entry point for POSIX code.  */
+/* regcomp takes a regular expression as a string and compiles it.
+
+   PREG is a regex_t *.  We do not expect any fields to be initialized,
+   since POSIX says we shouldn't.  Thus, we set
+
+     'buffer' to the compiled pattern;
+     'used' to the length of the compiled pattern;
+     'syntax' to RE_SYNTAX_POSIX_EXTENDED if the
+       REG_EXTENDED bit in CFLAGS is set; otherwise, to
+       RE_SYNTAX_POSIX_BASIC;
+     'newline_anchor' to REG_NEWLINE being set in CFLAGS;
+     'fastmap' to an allocated space for the fastmap;
+     'fastmap_accurate' to zero;
+     're_nsub' to the number of subexpressions in PATTERN.
+
+   PATTERN is the address of the pattern string.
+
+   CFLAGS is a series of bits which affect compilation.
+
+     If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
+     use POSIX basic syntax.
+
+     If REG_NEWLINE is set, then . and [^...] don't match newline.
+     Also, regexec will try a match beginning after every newline.
+
+     If REG_ICASE is set, then we considers upper- and lowercase
+     versions of letters to be equivalent when matching.
+
+     If REG_NOSUB is set, then when PREG is passed to regexec, that
+     routine will report only success or failure, and nothing about the
+     registers.
+
+   It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
+   the return codes and their meanings.)  */
+
+int
+regcomp (preg, pattern, cflags)
+    regex_t *_Restrict_ preg;
+    const char *_Restrict_ pattern;
+    int cflags;
+{
+  reg_errcode_t ret;
+  reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED
+                        : RE_SYNTAX_POSIX_BASIC);
+
+  preg->buffer = NULL;
+  preg->allocated = 0;
+  preg->used = 0;
+
+  /* Try to allocate space for the fastmap.  */
+  preg->fastmap = re_malloc (char, SBC_MAX);
+  if (BE (preg->fastmap == NULL, 0))
+    return REG_ESPACE;
+
+  syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0;
+
+  /* If REG_NEWLINE is set, newlines are treated differently.  */
+  if (cflags & REG_NEWLINE)
+    { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
+      syntax &= ~RE_DOT_NEWLINE;
+      syntax |= RE_HAT_LISTS_NOT_NEWLINE;
+      /* It also changes the matching behavior.  */
+      preg->newline_anchor = 1;
+    }
+  else
+    preg->newline_anchor = 0;
+  preg->no_sub = !!(cflags & REG_NOSUB);
+  preg->translate = NULL;
+
+  ret = re_compile_internal (preg, pattern, strlen (pattern), syntax);
+
+  /* POSIX doesn't distinguish between an unmatched open-group and an
+     unmatched close-group: both are REG_EPAREN.  */
+  if (ret == REG_ERPAREN)
+    ret = REG_EPAREN;
+
+  /* We have already checked preg->fastmap != NULL.  */
+  if (BE (ret == REG_NOERROR, 1))
+    /* Compute the fastmap now, since regexec cannot modify the pattern
+       buffer.  This function never fails in this implementation.  */
+    (void) re_compile_fastmap (preg);
+  else
+    {
+      /* Some error occurred while compiling the expression.  */
+      re_free (preg->fastmap);
+      preg->fastmap = NULL;
+    }
+
+  return (int) ret;
+}
+#ifdef _LIBC
+weak_alias (__regcomp, regcomp)
+#endif
+
+/* Returns a message corresponding to an error code, ERRCODE, returned
+   from either regcomp or regexec.   We don't use PREG here.  */
+
+#ifdef _LIBC
+size_t
+regerror (errcode, preg, errbuf, errbuf_size)
+    int errcode;
+    const regex_t *_Restrict_ preg;
+    char *_Restrict_ errbuf;
+    size_t errbuf_size;
+#else /* size_t might promote */
+size_t
+regerror (int errcode, const regex_t *_Restrict_ preg,
+         char *_Restrict_ errbuf, size_t errbuf_size)
+#endif
+{
+  const char *msg;
+  size_t msg_size;
+
+  if (BE (errcode < 0
+         || errcode >= (int) (sizeof (__re_error_msgid_idx)
+                              / sizeof (__re_error_msgid_idx[0])), 0))
+    /* Only error codes returned by the rest of the code should be passed
+       to this routine.  If we are given anything else, or if other regex
+       code generates an invalid error code, then the program has a bug.
+       Dump core so we can fix it.  */
+    abort ();
+
+  msg = gettext (__re_error_msgid + __re_error_msgid_idx[errcode]);
+
+  msg_size = strlen (msg) + 1; /* Includes the null.  */
+
+  if (BE (errbuf_size != 0, 1))
+    {
+      size_t cpy_size = msg_size;
+      if (BE (msg_size > errbuf_size, 0))
+       {
+         cpy_size = errbuf_size - 1;
+         errbuf[cpy_size] = '\0';
+       }
+      memcpy (errbuf, msg, cpy_size);
+    }
+
+  return msg_size;
+}
+#ifdef _LIBC
+weak_alias (__regerror, regerror)
+#endif
+
+
+#ifdef RE_ENABLE_I18N
+/* This static array is used for the map to single-byte characters when
+   UTF-8 is used.  Otherwise we would allocate memory just to initialize
+   it the same all the time.  UTF-8 is the preferred encoding so this is
+   a worthwhile optimization.  */
+static const bitset_t utf8_sb_map =
+{
+  /* Set the first 128 bits.  */
+# if 4 * BITSET_WORD_BITS < ASCII_CHARS
+#  error "bitset_word_t is narrower than 32 bits"
+# elif 3 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX, BITSET_WORD_MAX, BITSET_WORD_MAX,
+# elif 2 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX, BITSET_WORD_MAX,
+# elif 1 * BITSET_WORD_BITS < ASCII_CHARS
+  BITSET_WORD_MAX,
+# endif
+  (BITSET_WORD_MAX
+   >> (SBC_MAX % BITSET_WORD_BITS == 0
+       ? 0
+       : BITSET_WORD_BITS - SBC_MAX % BITSET_WORD_BITS))
+};
+#endif
+
+
+static void
+free_dfa_content (re_dfa_t *dfa)
+{
+  Idx i, j;
+
+  if (dfa->nodes)
+    for (i = 0; i < dfa->nodes_len; ++i)
+      free_token (dfa->nodes + i);
+  re_free (dfa->nexts);
+  for (i = 0; i < dfa->nodes_len; ++i)
+    {
+      if (dfa->eclosures != NULL)
+       re_node_set_free (dfa->eclosures + i);
+      if (dfa->inveclosures != NULL)
+       re_node_set_free (dfa->inveclosures + i);
+      if (dfa->edests != NULL)
+       re_node_set_free (dfa->edests + i);
+    }
+  re_free (dfa->edests);
+  re_free (dfa->eclosures);
+  re_free (dfa->inveclosures);
+  re_free (dfa->nodes);
+
+  if (dfa->state_table)
+    for (i = 0; i <= dfa->state_hash_mask; ++i)
+      {
+       struct re_state_table_entry *entry = dfa->state_table + i;
+       for (j = 0; j < entry->num; ++j)
+         {
+           re_dfastate_t *state = entry->array[j];
+           free_state (state);
+         }
+       re_free (entry->array);
+      }
+  re_free (dfa->state_table);
+#ifdef RE_ENABLE_I18N
+  if (dfa->sb_char != utf8_sb_map)
+    re_free (dfa->sb_char);
+#endif
+  re_free (dfa->subexp_map);
+#ifdef DEBUG
+  re_free (dfa->re_str);
+#endif
+
+  re_free (dfa);
+}
+
+
+/* Free dynamically allocated space used by PREG.  */
+
+void
+regfree (preg)
+    regex_t *preg;
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  if (BE (dfa != NULL, 1))
+    free_dfa_content (dfa);
+  preg->buffer = NULL;
+  preg->allocated = 0;
+
+  re_free (preg->fastmap);
+  preg->fastmap = NULL;
+
+  re_free (preg->translate);
+  preg->translate = NULL;
+}
+#ifdef _LIBC
+weak_alias (__regfree, regfree)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+
+/* BSD has one and only one pattern buffer.  */
+static struct re_pattern_buffer re_comp_buf;
+
+char *
+# ifdef _LIBC
+/* Make these definitions weak in libc, so POSIX programs can redefine
+   these names if they don't use our functions, and still use
+   regcomp/regexec above without link errors.  */
+weak_function
+# endif
+re_comp (s)
+     const char *s;
+{
+  reg_errcode_t ret;
+  char *fastmap;
+
+  if (!s)
+    {
+      if (!re_comp_buf.buffer)
+       return gettext ("No previous regular expression");
+      return 0;
+    }
+
+  if (re_comp_buf.buffer)
+    {
+      fastmap = re_comp_buf.fastmap;
+      re_comp_buf.fastmap = NULL;
+      __regfree (&re_comp_buf);
+      memset (&re_comp_buf, '\0', sizeof (re_comp_buf));
+      re_comp_buf.fastmap = fastmap;
+    }
+
+  if (re_comp_buf.fastmap == NULL)
+    {
+      re_comp_buf.fastmap = (char *) malloc (SBC_MAX);
+      if (re_comp_buf.fastmap == NULL)
+       return (char *) gettext (__re_error_msgid
+                                + __re_error_msgid_idx[(int) REG_ESPACE]);
+    }
+
+  /* Since 're_exec' always passes NULL for the 'regs' argument, we
+     don't need to initialize the pattern buffer fields which affect it.  */
+
+  /* Match anchors at newlines.  */
+  re_comp_buf.newline_anchor = 1;
+
+  ret = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options);
+
+  if (!ret)
+    return NULL;
+
+  /* Yes, we're discarding 'const' here if !HAVE_LIBINTL.  */
+  return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
+}
+
+#ifdef _LIBC
+libc_freeres_fn (free_mem)
+{
+  __regfree (&re_comp_buf);
+}
+#endif
+
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.
+   Compile the regular expression PATTERN, whose length is LENGTH.
+   SYNTAX indicate regular expression's syntax.  */
+
+static reg_errcode_t
+re_compile_internal (regex_t *preg, const char * pattern, size_t length,
+                    reg_syntax_t syntax)
+{
+  reg_errcode_t err = REG_NOERROR;
+  re_dfa_t *dfa;
+  re_string_t regexp;
+
+  /* Initialize the pattern buffer.  */
+  preg->fastmap_accurate = 0;
+  preg->syntax = syntax;
+  preg->not_bol = preg->not_eol = 0;
+  preg->used = 0;
+  preg->re_nsub = 0;
+  preg->can_be_null = 0;
+  preg->regs_allocated = REGS_UNALLOCATED;
+
+  /* Initialize the dfa.  */
+  dfa = (re_dfa_t *) preg->buffer;
+  if (BE (preg->allocated < sizeof (re_dfa_t), 0))
+    {
+      /* If zero allocated, but buffer is non-null, try to realloc
+        enough space.  This loses if buffer's address is bogus, but
+        that is the user's responsibility.  If ->buffer is NULL this
+        is a simple allocation.  */
+      dfa = re_realloc (preg->buffer, re_dfa_t, 1);
+      if (dfa == NULL)
+       return REG_ESPACE;
+      preg->allocated = sizeof (re_dfa_t);
+      preg->buffer = (unsigned char *) dfa;
+    }
+  preg->used = sizeof (re_dfa_t);
+
+  err = init_dfa (dfa, length);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+#ifdef DEBUG
+  /* Note: length+1 will not overflow since it is checked in init_dfa.  */
+  dfa->re_str = re_malloc (char, length + 1);
+  strncpy (dfa->re_str, pattern, length + 1);
+#endif
+
+  __libc_lock_init (dfa->lock);
+
+  err = re_string_construct (&regexp, pattern, length, preg->translate,
+                            (syntax & RE_ICASE) != 0, dfa);
+  if (BE (err != REG_NOERROR, 0))
+    {
+    re_compile_internal_free_return:
+      free_workarea_compile (preg);
+      re_string_destruct (&regexp);
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+      return err;
+    }
+
+  /* Parse the regular expression, and build a structure tree.  */
+  preg->re_nsub = 0;
+  dfa->str_tree = parse (&regexp, preg, syntax, &err);
+  if (BE (dfa->str_tree == NULL, 0))
+    goto re_compile_internal_free_return;
+
+  /* Analyze the tree and create the nfa.  */
+  err = analyze (preg);
+  if (BE (err != REG_NOERROR, 0))
+    goto re_compile_internal_free_return;
+
+#ifdef RE_ENABLE_I18N
+  /* If possible, do searching in single byte encoding to speed things up.  */
+  if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
+    optimize_utf8 (dfa);
+#endif
+
+  /* Then create the initial state of the dfa.  */
+  err = create_initial_state (dfa);
+
+  /* Release work areas.  */
+  free_workarea_compile (preg);
+  re_string_destruct (&regexp);
+
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_dfa_content (dfa);
+      preg->buffer = NULL;
+      preg->allocated = 0;
+    }
+
+  return err;
+}
+
+/* Initialize DFA.  We use the length of the regular expression PAT_LEN
+   as the initial length of some arrays.  */
+
+static reg_errcode_t
+init_dfa (re_dfa_t *dfa, size_t pat_len)
+{
+  __re_size_t table_size;
+#ifndef _LIBC
+  char *codeset_name;
+#endif
+#ifdef RE_ENABLE_I18N
+  size_t max_i18n_object_size = MAX (sizeof (wchar_t), sizeof (wctype_t));
+#else
+  size_t max_i18n_object_size = 0;
+#endif
+  size_t max_object_size =
+    MAX (sizeof (struct re_state_table_entry),
+        MAX (sizeof (re_token_t),
+             MAX (sizeof (re_node_set),
+                  MAX (sizeof (regmatch_t),
+                       max_i18n_object_size))));
+
+  memset (dfa, '\0', sizeof (re_dfa_t));
+
+  /* Force allocation of str_tree_storage the first time.  */
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+
+  /* Avoid overflows.  The extra "/ 2" is for the table_size doubling
+     calculation below, and for similar doubling calculations
+     elsewhere.  And it's <= rather than <, because some of the
+     doubling calculations add 1 afterwards.  */
+  if (BE (SIZE_MAX / max_object_size / 2 <= pat_len, 0))
+    return REG_ESPACE;
+
+  dfa->nodes_alloc = pat_len + 1;
+  dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
+
+  /*  table_size = 2 ^ ceil(log pat_len) */
+  for (table_size = 1; ; table_size <<= 1)
+    if (table_size > pat_len)
+      break;
+
+  dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size);
+  dfa->state_hash_mask = table_size - 1;
+
+  dfa->mb_cur_max = MB_CUR_MAX;
+#ifdef _LIBC
+  if (dfa->mb_cur_max == 6
+      && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0)
+    dfa->is_utf8 = 1;
+  dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII)
+                      != 0);
+#else
+  codeset_name = nl_langinfo (CODESET);
+  if (strcasecmp (codeset_name, "UTF-8") == 0
+      || strcasecmp (codeset_name, "UTF8") == 0)
+    dfa->is_utf8 = 1;
+
+  /* We check exhaustively in the loop below if this charset is a
+     superset of ASCII.  */
+  dfa->map_notascii = 0;
+#endif
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      if (dfa->is_utf8)
+       dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map;
+      else
+       {
+         int i, j, ch;
+
+         dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+         if (BE (dfa->sb_char == NULL, 0))
+           return REG_ESPACE;
+
+         /* Set the bits corresponding to single byte chars.  */
+         for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+           for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+             {
+               wint_t wch = __btowc (ch);
+               if (wch != WEOF)
+                 dfa->sb_char[i] |= (bitset_word_t) 1 << j;
+# ifndef _LIBC
+               if (isascii (ch) && wch != ch)
+                 dfa->map_notascii = 1;
+# endif
+             }
+       }
+    }
+#endif
+
+  if (BE (dfa->nodes == NULL || dfa->state_table == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+/* Initialize WORD_CHAR table, which indicate which character is
+   "word".  In this case "word" means that it is the word construction
+   character used by some operators like "\<", "\>", etc.  */
+
+static void
+internal_function
+init_word_char (re_dfa_t *dfa)
+{
+  int i, j, ch;
+  dfa->word_ops_used = 1;
+  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
+    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
+      if (isalnum (ch) || ch == '_')
+       dfa->word_char[i] |= (bitset_word_t) 1 << j;
+}
+
+/* Free the work area which are only used while compiling.  */
+
+static void
+free_workarea_compile (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_storage_t *storage, *next;
+  for (storage = dfa->str_tree_storage; storage; storage = next)
+    {
+      next = storage->next;
+      re_free (storage);
+    }
+  dfa->str_tree_storage = NULL;
+  dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
+  dfa->str_tree = NULL;
+  re_free (dfa->org_indices);
+  dfa->org_indices = NULL;
+}
+
+/* Create initial states for all contexts.  */
+
+static reg_errcode_t
+create_initial_state (re_dfa_t *dfa)
+{
+  Idx first, i;
+  reg_errcode_t err;
+  re_node_set init_nodes;
+
+  /* Initial states have the epsilon closure of the node which is
+     the first node of the regular expression.  */
+  first = dfa->str_tree->first->node_idx;
+  dfa->init_node = first;
+  err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* The back-references which are in initial states can epsilon transit,
+     since in this case all of the subexpressions can be null.
+     Then we add epsilon closures of the nodes which are the next nodes of
+     the back-references.  */
+  if (dfa->nbackref > 0)
+    for (i = 0; i < init_nodes.nelem; ++i)
+      {
+       Idx node_idx = init_nodes.elems[i];
+       re_token_type_t type = dfa->nodes[node_idx].type;
+
+       Idx clexp_idx;
+       if (type != OP_BACK_REF)
+         continue;
+       for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx)
+         {
+           re_token_t *clexp_node;
+           clexp_node = dfa->nodes + init_nodes.elems[clexp_idx];
+           if (clexp_node->type == OP_CLOSE_SUBEXP
+               && clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx)
+             break;
+         }
+       if (clexp_idx == init_nodes.nelem)
+         continue;
+
+       if (type == OP_BACK_REF)
+         {
+           Idx dest_idx = dfa->edests[node_idx].elems[0];
+           if (!re_node_set_contains (&init_nodes, dest_idx))
+             {
+               reg_errcode_t merge_err
+                  = re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
+               if (merge_err != REG_NOERROR)
+                 return merge_err;
+               i = 0;
+             }
+         }
+      }
+
+  /* It must be the first time to invoke acquire_state.  */
+  dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
+  /* We don't check ERR here, since the initial state must not be NULL.  */
+  if (BE (dfa->init_state == NULL, 0))
+    return err;
+  if (dfa->init_state->has_constraint)
+    {
+      dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
+                                                      CONTEXT_WORD);
+      dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes,
+                                                    CONTEXT_NEWLINE);
+      dfa->init_state_begbuf = re_acquire_state_context (&err, dfa,
+                                                        &init_nodes,
+                                                        CONTEXT_NEWLINE
+                                                        | CONTEXT_BEGBUF);
+      if (BE (dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+             || dfa->init_state_begbuf == NULL, 0))
+       return err;
+    }
+  else
+    dfa->init_state_word = dfa->init_state_nl
+      = dfa->init_state_begbuf = dfa->init_state;
+
+  re_node_set_free (&init_nodes);
+  return REG_NOERROR;
+}
+
+#ifdef RE_ENABLE_I18N
+/* If it is possible to do searching in single byte encoding instead of UTF-8
+   to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change
+   DFA nodes where needed.  */
+
+static void
+optimize_utf8 (re_dfa_t *dfa)
+{
+  Idx node;
+  int i;
+  bool mb_chars = false;
+  bool has_period = false;
+
+  for (node = 0; node < dfa->nodes_len; ++node)
+    switch (dfa->nodes[node].type)
+      {
+      case CHARACTER:
+       if (dfa->nodes[node].opr.c >= ASCII_CHARS)
+         mb_chars = true;
+       break;
+      case ANCHOR:
+       switch (dfa->nodes[node].opr.ctx_type)
+         {
+         case LINE_FIRST:
+         case LINE_LAST:
+         case BUF_FIRST:
+         case BUF_LAST:
+           break;
+         default:
+           /* Word anchors etc. cannot be handled.  It's okay to test
+              opr.ctx_type since constraints (for all DFA nodes) are
+              created by ORing one or more opr.ctx_type values.  */
+           return;
+         }
+       break;
+      case OP_PERIOD:
+       has_period = true;
+       break;
+      case OP_BACK_REF:
+      case OP_ALT:
+      case END_OF_RE:
+      case OP_DUP_ASTERISK:
+      case OP_OPEN_SUBEXP:
+      case OP_CLOSE_SUBEXP:
+       break;
+      case COMPLEX_BRACKET:
+       return;
+      case SIMPLE_BRACKET:
+       /* Just double check.  */
+       {
+         int rshift = (ASCII_CHARS % BITSET_WORD_BITS == 0
+                       ? 0
+                       : BITSET_WORD_BITS - ASCII_CHARS % BITSET_WORD_BITS);
+         for (i = ASCII_CHARS / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
+           {
+             if (dfa->nodes[node].opr.sbcset[i] >> rshift != 0)
+               return;
+             rshift = 0;
+           }
+       }
+       break;
+      default:
+       abort ();
+      }
+
+  if (mb_chars || has_period)
+    for (node = 0; node < dfa->nodes_len; ++node)
+      {
+       if (dfa->nodes[node].type == CHARACTER
+           && dfa->nodes[node].opr.c >= ASCII_CHARS)
+         dfa->nodes[node].mb_partial = 0;
+       else if (dfa->nodes[node].type == OP_PERIOD)
+         dfa->nodes[node].type = OP_UTF8_PERIOD;
+      }
+
+  /* The search can be in single byte locale.  */
+  dfa->mb_cur_max = 1;
+  dfa->is_utf8 = 0;
+  dfa->has_mb_node = dfa->nbackref > 0 || has_period;
+}
+#endif
+
+/* Analyze the structure tree, and calculate "first", "next", "edest",
+   "eclosure", and "inveclosure".  */
+
+static reg_errcode_t
+analyze (regex_t *preg)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  reg_errcode_t ret;
+
+  /* Allocate arrays.  */
+  dfa->nexts = re_malloc (Idx, dfa->nodes_alloc);
+  dfa->org_indices = re_malloc (Idx, dfa->nodes_alloc);
+  dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
+  dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
+  if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL
+         || dfa->eclosures == NULL, 0))
+    return REG_ESPACE;
+
+  dfa->subexp_map = re_malloc (Idx, preg->re_nsub);
+  if (dfa->subexp_map != NULL)
+    {
+      Idx i;
+      for (i = 0; i < preg->re_nsub; i++)
+       dfa->subexp_map[i] = i;
+      preorder (dfa->str_tree, optimize_subexps, dfa);
+      for (i = 0; i < preg->re_nsub; i++)
+       if (dfa->subexp_map[i] != i)
+         break;
+      if (i == preg->re_nsub)
+       {
+         free (dfa->subexp_map);
+         dfa->subexp_map = NULL;
+       }
+    }
+
+  ret = postorder (dfa->str_tree, lower_subexps, preg);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = postorder (dfa->str_tree, calc_first, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  preorder (dfa->str_tree, calc_next, dfa);
+  ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+  ret = calc_eclosure (dfa);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  /* We only need this during the prune_impossible_nodes pass in regexec.c;
+     skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
+  if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
+      || dfa->nbackref)
+    {
+      dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
+      if (BE (dfa->inveclosures == NULL, 0))
+       return REG_ESPACE;
+      ret = calc_inveclosure (dfa);
+    }
+
+  return ret;
+}
+
+/* Our parse trees are very unbalanced, so we cannot use a stack to
+   implement parse tree visits.  Instead, we use parent pointers and
+   some hairy code in these two functions.  */
+static reg_errcode_t
+postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+          void *extra)
+{
+  bin_tree_t *node, *prev;
+
+  for (node = root; ; )
+    {
+      /* Descend down the tree, preferably to the left (or to the right
+        if that's the only child).  */
+      while (node->left || node->right)
+       if (node->left)
+         node = node->left;
+       else
+         node = node->right;
+
+      do
+       {
+         reg_errcode_t err = fn (extra, node);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+         if (node->parent == NULL)
+           return REG_NOERROR;
+         prev = node;
+         node = node->parent;
+       }
+      /* Go up while we have a node that is reached from the right.  */
+      while (node->right == prev || node->right == NULL);
+      node = node->right;
+    }
+}
+
+static reg_errcode_t
+preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
+         void *extra)
+{
+  bin_tree_t *node;
+
+  for (node = root; ; )
+    {
+      reg_errcode_t err = fn (extra, node);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+       node = node->left;
+      else
+       {
+         bin_tree_t *prev = NULL;
+         while (node->right == prev || node->right == NULL)
+           {
+             prev = node;
+             node = node->parent;
+             if (!node)
+               return REG_NOERROR;
+           }
+         node = node->right;
+       }
+    }
+}
+
+/* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
+   re_search_internal to map the inner one's opr.idx to this one's.  Adjust
+   backreferences as well.  Requires a preorder visit.  */
+static reg_errcode_t
+optimize_subexps (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+
+  if (node->token.type == OP_BACK_REF && dfa->subexp_map)
+    {
+      int idx = node->token.opr.idx;
+      node->token.opr.idx = dfa->subexp_map[idx];
+      dfa->used_bkref_map |= 1 << node->token.opr.idx;
+    }
+
+  else if (node->token.type == SUBEXP
+          && node->left && node->left->token.type == SUBEXP)
+    {
+      Idx other_idx = node->left->token.opr.idx;
+
+      node->left = node->left->left;
+      if (node->left)
+       node->left->parent = node;
+
+      dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
+      if (other_idx < BITSET_WORD_BITS)
+       dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
+    }
+
+  return REG_NOERROR;
+}
+
+/* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
+   of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
+static reg_errcode_t
+lower_subexps (void *extra, bin_tree_t *node)
+{
+  regex_t *preg = (regex_t *) extra;
+  reg_errcode_t err = REG_NOERROR;
+
+  if (node->left && node->left->token.type == SUBEXP)
+    {
+      node->left = lower_subexp (&err, preg, node->left);
+      if (node->left)
+       node->left->parent = node;
+    }
+  if (node->right && node->right->token.type == SUBEXP)
+    {
+      node->right = lower_subexp (&err, preg, node->right);
+      if (node->right)
+       node->right->parent = node;
+    }
+
+  return err;
+}
+
+static bin_tree_t *
+lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *body = node->left;
+  bin_tree_t *op, *cls, *tree1, *tree;
+
+  if (preg->no_sub
+      /* We do not optimize empty subexpressions, because otherwise we may
+        have bad CONCAT nodes with NULL children.  This is obviously not
+        very common, so we do not lose much.  An example that triggers
+        this case is the sed "script" /\(\)/x.  */
+      && node->left != NULL
+      && (node->token.opr.idx >= BITSET_WORD_BITS
+         || !(dfa->used_bkref_map
+              & ((bitset_word_t) 1 << node->token.opr.idx))))
+    return node->left;
+
+  /* Convert the SUBEXP node to the concatenation of an
+     OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
+  op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
+  cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
+  tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
+  tree = create_tree (dfa, op, tree1, CONCAT);
+  if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
+  op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
+  return tree;
+}
+
+/* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
+   nodes.  Requires a postorder visit.  */
+static reg_errcode_t
+calc_first (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  if (node->token.type == CONCAT)
+    {
+      node->first = node->left->first;
+      node->node_idx = node->left->node_idx;
+    }
+  else
+    {
+      node->first = node;
+      node->node_idx = re_dfa_add_node (dfa, node->token);
+      if (BE (node->node_idx == REG_MISSING, 0))
+       return REG_ESPACE;
+      if (node->token.type == ANCHOR)
+       dfa->nodes[node->node_idx].constraint = node->token.opr.ctx_type;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 2: compute NEXT on the tree.  Preorder visit.  */
+static reg_errcode_t
+calc_next (void *extra, bin_tree_t *node)
+{
+  switch (node->token.type)
+    {
+    case OP_DUP_ASTERISK:
+      node->left->next = node;
+      break;
+    case CONCAT:
+      node->left->next = node->right->first;
+      node->right->next = node->next;
+      break;
+    default:
+      if (node->left)
+       node->left->next = node->next;
+      if (node->right)
+       node->right->next = node->next;
+      break;
+    }
+  return REG_NOERROR;
+}
+
+/* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
+static reg_errcode_t
+link_nfa_nodes (void *extra, bin_tree_t *node)
+{
+  re_dfa_t *dfa = (re_dfa_t *) extra;
+  Idx idx = node->node_idx;
+  reg_errcode_t err = REG_NOERROR;
+
+  switch (node->token.type)
+    {
+    case CONCAT:
+      break;
+
+    case END_OF_RE:
+      assert (node->next == NULL);
+      break;
+
+    case OP_DUP_ASTERISK:
+    case OP_ALT:
+      {
+       Idx left, right;
+       dfa->has_plural_match = 1;
+       if (node->left != NULL)
+         left = node->left->first->node_idx;
+       else
+         left = node->next->node_idx;
+       if (node->right != NULL)
+         right = node->right->first->node_idx;
+       else
+         right = node->next->node_idx;
+       assert (REG_VALID_INDEX (left));
+       assert (REG_VALID_INDEX (right));
+       err = re_node_set_init_2 (dfa->edests + idx, left, right);
+      }
+      break;
+
+    case ANCHOR:
+    case OP_OPEN_SUBEXP:
+    case OP_CLOSE_SUBEXP:
+      err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
+      break;
+
+    case OP_BACK_REF:
+      dfa->nexts[idx] = node->next->node_idx;
+      if (node->token.type == OP_BACK_REF)
+       err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
+      break;
+
+    default:
+      assert (!IS_EPSILON_NODE (node->token.type));
+      dfa->nexts[idx] = node->next->node_idx;
+      break;
+    }
+
+  return err;
+}
+
+/* Duplicate the epsilon closure of the node ROOT_NODE.
+   Note that duplicated nodes have constraint INIT_CONSTRAINT in addition
+   to their own constraint.  */
+
+static reg_errcode_t
+internal_function
+duplicate_node_closure (re_dfa_t *dfa, Idx top_org_node, Idx top_clone_node,
+                       Idx root_node, unsigned int init_constraint)
+{
+  Idx org_node, clone_node;
+  bool ok;
+  unsigned int constraint = init_constraint;
+  for (org_node = top_org_node, clone_node = top_clone_node;;)
+    {
+      Idx org_dest, clone_dest;
+      if (dfa->nodes[org_node].type == OP_BACK_REF)
+       {
+         /* If the back reference epsilon-transit, its destination must
+            also have the constraint.  Then duplicate the epsilon closure
+            of the destination of the back reference, and store it in
+            edests of the back reference.  */
+         org_dest = dfa->nexts[org_node];
+         re_node_set_empty (dfa->edests + clone_node);
+         clone_dest = duplicate_node (dfa, org_dest, constraint);
+         if (BE (clone_dest == REG_MISSING, 0))
+           return REG_ESPACE;
+         dfa->nexts[clone_node] = dfa->nexts[org_node];
+         ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+         if (BE (! ok, 0))
+           return REG_ESPACE;
+       }
+      else if (dfa->edests[org_node].nelem == 0)
+       {
+         /* In case of the node can't epsilon-transit, don't duplicate the
+            destination and store the original destination as the
+            destination of the node.  */
+         dfa->nexts[clone_node] = dfa->nexts[org_node];
+         break;
+       }
+      else if (dfa->edests[org_node].nelem == 1)
+       {
+         /* In case of the node can epsilon-transit, and it has only one
+            destination.  */
+         org_dest = dfa->edests[org_node].elems[0];
+         re_node_set_empty (dfa->edests + clone_node);
+         /* If the node is root_node itself, it means the epsilon closure
+            has a loop.  Then tie it to the destination of the root_node.  */
+         if (org_node == root_node && clone_node != org_node)
+           {
+             ok = re_node_set_insert (dfa->edests + clone_node, org_dest);
+             if (BE (! ok, 0))
+               return REG_ESPACE;
+             break;
+           }
+         /* In case the node has another constraint, append it.  */
+         constraint |= dfa->nodes[org_node].constraint;
+         clone_dest = duplicate_node (dfa, org_dest, constraint);
+         if (BE (clone_dest == REG_MISSING, 0))
+           return REG_ESPACE;
+         ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+         if (BE (! ok, 0))
+           return REG_ESPACE;
+       }
+      else /* dfa->edests[org_node].nelem == 2 */
+       {
+         /* In case of the node can epsilon-transit, and it has two
+            destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
+         org_dest = dfa->edests[org_node].elems[0];
+         re_node_set_empty (dfa->edests + clone_node);
+         /* Search for a duplicated node which satisfies the constraint.  */
+         clone_dest = search_duplicated_node (dfa, org_dest, constraint);
+         if (clone_dest == REG_MISSING)
+           {
+             /* There is no such duplicated node, create a new one.  */
+             reg_errcode_t err;
+             clone_dest = duplicate_node (dfa, org_dest, constraint);
+             if (BE (clone_dest == REG_MISSING, 0))
+               return REG_ESPACE;
+             ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+             if (BE (! ok, 0))
+               return REG_ESPACE;
+             err = duplicate_node_closure (dfa, org_dest, clone_dest,
+                                           root_node, constraint);
+             if (BE (err != REG_NOERROR, 0))
+               return err;
+           }
+         else
+           {
+             /* There is a duplicated node which satisfies the constraint,
+                use it to avoid infinite loop.  */
+             ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+             if (BE (! ok, 0))
+               return REG_ESPACE;
+           }
+
+         org_dest = dfa->edests[org_node].elems[1];
+         clone_dest = duplicate_node (dfa, org_dest, constraint);
+         if (BE (clone_dest == REG_MISSING, 0))
+           return REG_ESPACE;
+         ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
+         if (BE (! ok, 0))
+           return REG_ESPACE;
+       }
+      org_node = org_dest;
+      clone_node = clone_dest;
+    }
+  return REG_NOERROR;
+}
+
+/* Search for a node which is duplicated from the node ORG_NODE, and
+   satisfies the constraint CONSTRAINT.  */
+
+static Idx
+search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
+                       unsigned int constraint)
+{
+  Idx idx;
+  for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
+    {
+      if (org_node == dfa->org_indices[idx]
+         && constraint == dfa->nodes[idx].constraint)
+       return idx; /* Found.  */
+    }
+  return REG_MISSING; /* Not found.  */
+}
+
+/* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
+   Return the index of the new node, or REG_MISSING if insufficient storage is
+   available.  */
+
+static Idx
+duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint)
+{
+  Idx dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
+  if (BE (dup_idx != REG_MISSING, 1))
+    {
+      dfa->nodes[dup_idx].constraint = constraint;
+      dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].constraint;
+      dfa->nodes[dup_idx].duplicated = 1;
+
+      /* Store the index of the original node.  */
+      dfa->org_indices[dup_idx] = org_idx;
+    }
+  return dup_idx;
+}
+
+static reg_errcode_t
+calc_inveclosure (re_dfa_t *dfa)
+{
+  Idx src, idx;
+  bool ok;
+  for (idx = 0; idx < dfa->nodes_len; ++idx)
+    re_node_set_init_empty (dfa->inveclosures + idx);
+
+  for (src = 0; src < dfa->nodes_len; ++src)
+    {
+      Idx *elems = dfa->eclosures[src].elems;
+      for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
+       {
+         ok = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
+         if (BE (! ok, 0))
+           return REG_ESPACE;
+       }
+    }
+
+  return REG_NOERROR;
+}
+
+/* Calculate "eclosure" for all the node in DFA.  */
+
+static reg_errcode_t
+calc_eclosure (re_dfa_t *dfa)
+{
+  Idx node_idx;
+  bool incomplete;
+#ifdef DEBUG
+  assert (dfa->nodes_len > 0);
+#endif
+  incomplete = false;
+  /* For each nodes, calculate epsilon closure.  */
+  for (node_idx = 0; ; ++node_idx)
+    {
+      reg_errcode_t err;
+      re_node_set eclosure_elem;
+      if (node_idx == dfa->nodes_len)
+       {
+         if (!incomplete)
+           break;
+         incomplete = false;
+         node_idx = 0;
+       }
+
+#ifdef DEBUG
+      assert (dfa->eclosures[node_idx].nelem != REG_MISSING);
+#endif
+
+      /* If we have already calculated, skip it.  */
+      if (dfa->eclosures[node_idx].nelem != 0)
+       continue;
+      /* Calculate epsilon closure of 'node_idx'.  */
+      err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, true);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+
+      if (dfa->eclosures[node_idx].nelem == 0)
+       {
+         incomplete = true;
+         re_node_set_free (&eclosure_elem);
+       }
+    }
+  return REG_NOERROR;
+}
+
+/* Calculate epsilon closure of NODE.  */
+
+static reg_errcode_t
+calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
+{
+  reg_errcode_t err;
+  Idx i;
+  re_node_set eclosure;
+  bool ok;
+  bool incomplete = false;
+  err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  /* This indicates that we are calculating this node now.
+     We reference this value to avoid infinite loop.  */
+  dfa->eclosures[node].nelem = REG_MISSING;
+
+  /* If the current node has constraints, duplicate all nodes
+     since they must inherit the constraints.  */
+  if (dfa->nodes[node].constraint
+      && dfa->edests[node].nelem
+      && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
+    {
+      err = duplicate_node_closure (dfa, node, node, node,
+                                   dfa->nodes[node].constraint);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+    }
+
+  /* Expand each epsilon destination nodes.  */
+  if (IS_EPSILON_NODE(dfa->nodes[node].type))
+    for (i = 0; i < dfa->edests[node].nelem; ++i)
+      {
+       re_node_set eclosure_elem;
+       Idx edest = dfa->edests[node].elems[i];
+       /* If calculating the epsilon closure of 'edest' is in progress,
+          return intermediate result.  */
+       if (dfa->eclosures[edest].nelem == REG_MISSING)
+         {
+           incomplete = true;
+           continue;
+         }
+       /* If we haven't calculated the epsilon closure of 'edest' yet,
+          calculate now. Otherwise use calculated epsilon closure.  */
+       if (dfa->eclosures[edest].nelem == 0)
+         {
+           err = calc_eclosure_iter (&eclosure_elem, dfa, edest, false);
+           if (BE (err != REG_NOERROR, 0))
+             return err;
+         }
+       else
+         eclosure_elem = dfa->eclosures[edest];
+       /* Merge the epsilon closure of 'edest'.  */
+       err = re_node_set_merge (&eclosure, &eclosure_elem);
+       if (BE (err != REG_NOERROR, 0))
+         return err;
+       /* If the epsilon closure of 'edest' is incomplete,
+          the epsilon closure of this node is also incomplete.  */
+       if (dfa->eclosures[edest].nelem == 0)
+         {
+           incomplete = true;
+           re_node_set_free (&eclosure_elem);
+         }
+      }
+
+  /* An epsilon closure includes itself.  */
+  ok = re_node_set_insert (&eclosure, node);
+  if (BE (! ok, 0))
+    return REG_ESPACE;
+  if (incomplete && !root)
+    dfa->eclosures[node].nelem = 0;
+  else
+    dfa->eclosures[node] = eclosure;
+  *new_set = eclosure;
+  return REG_NOERROR;
+}
+
+/* Functions for token which are used in the parser.  */
+
+/* Fetch a token from INPUT.
+   We must not use this function inside bracket expressions.  */
+
+static void
+internal_function
+fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
+{
+  re_string_skip_bytes (input, peek_token (result, input, syntax));
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function inside bracket expressions.  */
+
+static int
+internal_function
+peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+  token->word_char = 0;
+#ifdef RE_ENABLE_I18N
+  token->mb_partial = 0;
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      token->mb_partial = 1;
+      return 1;
+    }
+#endif
+  if (c == '\\')
+    {
+      unsigned char c2;
+      if (re_string_cur_idx (input) + 1 >= re_string_length (input))
+       {
+         token->type = BACK_SLASH;
+         return 1;
+       }
+
+      c2 = re_string_peek_byte_case (input, 1);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+      if (input->mb_cur_max > 1)
+       {
+         wint_t wc = re_string_wchar_at (input,
+                                         re_string_cur_idx (input) + 1);
+         token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+       }
+      else
+#endif
+       token->word_char = IS_WORD_CHAR (c2) != 0;
+
+      switch (c2)
+       {
+       case '|':
+         if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR))
+           token->type = OP_ALT;
+         break;
+       case '1': case '2': case '3': case '4': case '5':
+       case '6': case '7': case '8': case '9':
+         if (!(syntax & RE_NO_BK_REFS))
+           {
+             token->type = OP_BACK_REF;
+             token->opr.idx = c2 - '1';
+           }
+         break;
+       case '<':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = WORD_FIRST;
+           }
+         break;
+       case '>':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = WORD_LAST;
+           }
+         break;
+       case 'b':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = WORD_DELIM;
+           }
+         break;
+       case 'B':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = NOT_WORD_DELIM;
+           }
+         break;
+       case 'w':
+         if (!(syntax & RE_NO_GNU_OPS))
+           token->type = OP_WORD;
+         break;
+       case 'W':
+         if (!(syntax & RE_NO_GNU_OPS))
+           token->type = OP_NOTWORD;
+         break;
+       case 's':
+         if (!(syntax & RE_NO_GNU_OPS))
+           token->type = OP_SPACE;
+         break;
+       case 'S':
+         if (!(syntax & RE_NO_GNU_OPS))
+           token->type = OP_NOTSPACE;
+         break;
+       case '`':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = BUF_FIRST;
+           }
+         break;
+       case '\'':
+         if (!(syntax & RE_NO_GNU_OPS))
+           {
+             token->type = ANCHOR;
+             token->opr.ctx_type = BUF_LAST;
+           }
+         break;
+       case '(':
+         if (!(syntax & RE_NO_BK_PARENS))
+           token->type = OP_OPEN_SUBEXP;
+         break;
+       case ')':
+         if (!(syntax & RE_NO_BK_PARENS))
+           token->type = OP_CLOSE_SUBEXP;
+         break;
+       case '+':
+         if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+           token->type = OP_DUP_PLUS;
+         break;
+       case '?':
+         if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
+           token->type = OP_DUP_QUESTION;
+         break;
+       case '{':
+         if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+           token->type = OP_OPEN_DUP_NUM;
+         break;
+       case '}':
+         if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
+           token->type = OP_CLOSE_DUP_NUM;
+         break;
+       default:
+         break;
+       }
+      return 2;
+    }
+
+  token->type = CHARACTER;
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input));
+      token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
+    }
+  else
+#endif
+    token->word_char = IS_WORD_CHAR (token->opr.c);
+
+  switch (c)
+    {
+    case '\n':
+      if (syntax & RE_NEWLINE_ALT)
+       token->type = OP_ALT;
+      break;
+    case '|':
+      if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR))
+       token->type = OP_ALT;
+      break;
+    case '*':
+      token->type = OP_DUP_ASTERISK;
+      break;
+    case '+':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+       token->type = OP_DUP_PLUS;
+      break;
+    case '?':
+      if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
+       token->type = OP_DUP_QUESTION;
+      break;
+    case '{':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+       token->type = OP_OPEN_DUP_NUM;
+      break;
+    case '}':
+      if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
+       token->type = OP_CLOSE_DUP_NUM;
+      break;
+    case '(':
+      if (syntax & RE_NO_BK_PARENS)
+       token->type = OP_OPEN_SUBEXP;
+      break;
+    case ')':
+      if (syntax & RE_NO_BK_PARENS)
+       token->type = OP_CLOSE_SUBEXP;
+      break;
+    case '[':
+      token->type = OP_OPEN_BRACKET;
+      break;
+    case '.':
+      token->type = OP_PERIOD;
+      break;
+    case '^':
+      if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE)) &&
+         re_string_cur_idx (input) != 0)
+       {
+         char prev = re_string_peek_byte (input, -1);
+         if (!(syntax & RE_NEWLINE_ALT) || prev != '\n')
+           break;
+       }
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_FIRST;
+      break;
+    case '$':
+      if (!(syntax & RE_CONTEXT_INDEP_ANCHORS) &&
+         re_string_cur_idx (input) + 1 != re_string_length (input))
+       {
+         re_token_t next;
+         re_string_skip_bytes (input, 1);
+         peek_token (&next, input, syntax);
+         re_string_skip_bytes (input, -1);
+         if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP)
+           break;
+       }
+      token->type = ANCHOR;
+      token->opr.ctx_type = LINE_LAST;
+      break;
+    default:
+      break;
+    }
+  return 1;
+}
+
+/* Peek a token from INPUT, and return the length of the token.
+   We must not use this function out of bracket expressions.  */
+
+static int
+internal_function
+peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
+{
+  unsigned char c;
+  if (re_string_eoi (input))
+    {
+      token->type = END_OF_RE;
+      return 0;
+    }
+  c = re_string_peek_byte (input, 0);
+  token->opr.c = c;
+
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1 &&
+      !re_string_first_byte (input, re_string_cur_idx (input)))
+    {
+      token->type = CHARACTER;
+      return 1;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS)
+      && re_string_cur_idx (input) + 1 < re_string_length (input))
+    {
+      /* In this case, '\' escape a character.  */
+      unsigned char c2;
+      re_string_skip_bytes (input, 1);
+      c2 = re_string_peek_byte (input, 0);
+      token->opr.c = c2;
+      token->type = CHARACTER;
+      return 1;
+    }
+  if (c == '[') /* '[' is a special char in a bracket exps.  */
+    {
+      unsigned char c2;
+      int token_len;
+      if (re_string_cur_idx (input) + 1 < re_string_length (input))
+       c2 = re_string_peek_byte (input, 1);
+      else
+       c2 = 0;
+      token->opr.c = c2;
+      token_len = 2;
+      switch (c2)
+       {
+       case '.':
+         token->type = OP_OPEN_COLL_ELEM;
+         break;
+       case '=':
+         token->type = OP_OPEN_EQUIV_CLASS;
+         break;
+       case ':':
+         if (syntax & RE_CHAR_CLASSES)
+           {
+             token->type = OP_OPEN_CHAR_CLASS;
+             break;
+           }
+         /* else fall through.  */
+       default:
+         token->type = CHARACTER;
+         token->opr.c = c;
+         token_len = 1;
+         break;
+       }
+      return token_len;
+    }
+  switch (c)
+    {
+    case '-':
+      token->type = OP_CHARSET_RANGE;
+      break;
+    case ']':
+      token->type = OP_CLOSE_BRACKET;
+      break;
+    case '^':
+      token->type = OP_NON_MATCH_LIST;
+      break;
+    default:
+      token->type = CHARACTER;
+    }
+  return 1;
+}
+
+/* Functions for parser.  */
+
+/* Entry point of the parser.
+   Parse the regular expression REGEXP and return the structure tree.
+   If an error is occured, ERR is set by error code, and return NULL.
+   This function build the following tree, from regular expression <reg_exp>:
+          CAT
+          / \
+         /   \
+   <reg_exp>  EOR
+
+   CAT means concatenation.
+   EOR means end of regular expression.  */
+
+static bin_tree_t *
+parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
+       reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *eor, *root;
+  re_token_t current_token;
+  dfa->syntax = syntax;
+  fetch_token (&current_token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+  tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+  eor = create_tree (dfa, NULL, NULL, END_OF_RE);
+  if (tree != NULL)
+    root = create_tree (dfa, tree, eor, CONCAT);
+  else
+    root = eor;
+  if (BE (eor == NULL || root == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  return root;
+}
+
+/* This function build the following tree, from regular expression
+   <branch1>|<branch2>:
+          ALT
+          / \
+         /   \
+   <branch1> <branch2>
+
+   ALT means alternative, which represents the operator '|'.  */
+
+static bin_tree_t *
+parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+              reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree, *branch = NULL;
+  tree = parse_branch (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type == OP_ALT)
+    {
+      fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+      if (token->type != OP_ALT && token->type != END_OF_RE
+         && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+       {
+         branch = parse_branch (regexp, preg, token, syntax, nest, err);
+         if (BE (*err != REG_NOERROR && branch == NULL, 0))
+           return NULL;
+       }
+      else
+       branch = NULL;
+      tree = create_tree (dfa, tree, branch, OP_ALT);
+      if (BE (tree == NULL, 0))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   <exp1><exp2>:
+       CAT
+       / \
+       /   \
+   <exp1> <exp2>
+
+   CAT means concatenation.  */
+
+static bin_tree_t *
+parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
+             reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  bin_tree_t *tree, *expr;
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  tree = parse_expression (regexp, preg, token, syntax, nest, err);
+  if (BE (*err != REG_NOERROR && tree == NULL, 0))
+    return NULL;
+
+  while (token->type != OP_ALT && token->type != END_OF_RE
+        && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
+    {
+      expr = parse_expression (regexp, preg, token, syntax, nest, err);
+      if (BE (*err != REG_NOERROR && expr == NULL, 0))
+       {
+         return NULL;
+       }
+      if (tree != NULL && expr != NULL)
+       {
+         tree = create_tree (dfa, tree, expr, CONCAT);
+         if (tree == NULL)
+           {
+             *err = REG_ESPACE;
+             return NULL;
+           }
+       }
+      else if (tree == NULL)
+       tree = expr;
+      /* Otherwise expr == NULL, we don't need to create new tree.  */
+    }
+  return tree;
+}
+
+/* This function build the following tree, from regular expression a*:
+        *
+        |
+        a
+*/
+
+static bin_tree_t *
+parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
+                 reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  switch (token->type)
+    {
+    case CHARACTER:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+       {
+         while (!re_string_eoi (regexp)
+                && !re_string_first_byte (regexp, re_string_cur_idx (regexp)))
+           {
+             bin_tree_t *mbc_remain;
+             fetch_token (token, regexp, syntax);
+             mbc_remain = create_token_tree (dfa, NULL, NULL, token);
+             tree = create_tree (dfa, tree, mbc_remain, CONCAT);
+             if (BE (mbc_remain == NULL || tree == NULL, 0))
+               {
+                 *err = REG_ESPACE;
+                 return NULL;
+               }
+           }
+       }
+#endif
+      break;
+    case OP_OPEN_SUBEXP:
+      tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+       return NULL;
+      break;
+    case OP_OPEN_BRACKET:
+      tree = parse_bracket_exp (regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+       return NULL;
+      break;
+    case OP_BACK_REF:
+      if (!BE (dfa->completed_bkref_map & (1 << token->opr.idx), 1))
+       {
+         *err = REG_ESUBREG;
+         return NULL;
+       }
+      dfa->used_bkref_map |= 1 << token->opr.idx;
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+      ++dfa->nbackref;
+      dfa->has_mb_node = 1;
+      break;
+    case OP_OPEN_DUP_NUM:
+      if (syntax & RE_CONTEXT_INVALID_DUP)
+       {
+         *err = REG_BADRPT;
+         return NULL;
+       }
+      /* FALLTHROUGH */
+    case OP_DUP_ASTERISK:
+    case OP_DUP_PLUS:
+    case OP_DUP_QUESTION:
+      if (syntax & RE_CONTEXT_INVALID_OPS)
+       {
+         *err = REG_BADRPT;
+         return NULL;
+       }
+      else if (syntax & RE_CONTEXT_INDEP_OPS)
+       {
+         fetch_token (token, regexp, syntax);
+         return parse_expression (regexp, preg, token, syntax, nest, err);
+       }
+      /* else fall through  */
+    case OP_CLOSE_SUBEXP:
+      if ((token->type == OP_CLOSE_SUBEXP) &&
+         !(syntax & RE_UNMATCHED_RIGHT_PAREN_ORD))
+       {
+         *err = REG_ERPAREN;
+         return NULL;
+       }
+      /* else fall through  */
+    case OP_CLOSE_DUP_NUM:
+      /* We treat it as a normal character.  */
+
+      /* Then we can these characters as normal characters.  */
+      token->type = CHARACTER;
+      /* mb_partial and word_char bits should be initialized already
+        by peek_token.  */
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+      break;
+    case ANCHOR:
+      if ((token->opr.ctx_type
+          & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
+         && dfa->word_ops_used == 0)
+       init_word_char (dfa);
+      if (token->opr.ctx_type == WORD_DELIM
+         || token->opr.ctx_type == NOT_WORD_DELIM)
+       {
+         bin_tree_t *tree_first, *tree_last;
+         if (token->opr.ctx_type == WORD_DELIM)
+           {
+             token->opr.ctx_type = WORD_FIRST;
+             tree_first = create_token_tree (dfa, NULL, NULL, token);
+             token->opr.ctx_type = WORD_LAST;
+           }
+         else
+           {
+             token->opr.ctx_type = INSIDE_WORD;
+             tree_first = create_token_tree (dfa, NULL, NULL, token);
+             token->opr.ctx_type = INSIDE_NOTWORD;
+           }
+         tree_last = create_token_tree (dfa, NULL, NULL, token);
+         tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
+         if (BE (tree_first == NULL || tree_last == NULL || tree == NULL, 0))
+           {
+             *err = REG_ESPACE;
+             return NULL;
+           }
+       }
+      else
+       {
+         tree = create_token_tree (dfa, NULL, NULL, token);
+         if (BE (tree == NULL, 0))
+           {
+             *err = REG_ESPACE;
+             return NULL;
+           }
+       }
+      /* We must return here, since ANCHORs can't be followed
+        by repetition operators.
+        eg. RE"^*" is invalid or "<ANCHOR(^)><CHAR(*)>",
+            it must not be "<ANCHOR(^)><REPEAT(*)>".  */
+      fetch_token (token, regexp, syntax);
+      return tree;
+    case OP_PERIOD:
+      tree = create_token_tree (dfa, NULL, NULL, token);
+      if (BE (tree == NULL, 0))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+      if (dfa->mb_cur_max > 1)
+       dfa->has_mb_node = 1;
+      break;
+    case OP_WORD:
+    case OP_NOTWORD:
+      tree = build_charclass_op (dfa, regexp->trans,
+                                (const unsigned char *) "alnum",
+                                (const unsigned char *) "_",
+                                token->type == OP_NOTWORD, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+       return NULL;
+      break;
+    case OP_SPACE:
+    case OP_NOTSPACE:
+      tree = build_charclass_op (dfa, regexp->trans,
+                                (const unsigned char *) "space",
+                                (const unsigned char *) "",
+                                token->type == OP_NOTSPACE, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+       return NULL;
+      break;
+    case OP_ALT:
+    case END_OF_RE:
+      return NULL;
+    case BACK_SLASH:
+      *err = REG_EESCAPE;
+      return NULL;
+    default:
+      /* Must not happen?  */
+#ifdef DEBUG
+      assert (0);
+#endif
+      return NULL;
+    }
+  fetch_token (token, regexp, syntax);
+
+  while (token->type == OP_DUP_ASTERISK || token->type == OP_DUP_PLUS
+        || token->type == OP_DUP_QUESTION || token->type == OP_OPEN_DUP_NUM)
+    {
+      tree = parse_dup_op (tree, regexp, dfa, token, syntax, err);
+      if (BE (*err != REG_NOERROR && tree == NULL, 0))
+       return NULL;
+      /* In BRE consecutive duplications are not allowed.  */
+      if ((syntax & RE_CONTEXT_INVALID_DUP)
+         && (token->type == OP_DUP_ASTERISK
+             || token->type == OP_OPEN_DUP_NUM))
+       {
+         *err = REG_BADRPT;
+         return NULL;
+       }
+    }
+
+  return tree;
+}
+
+/* This function build the following tree, from regular expression
+   (<reg_exp>):
+        SUBEXP
+           |
+       <reg_exp>
+*/
+
+static bin_tree_t *
+parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
+              reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
+{
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+  bin_tree_t *tree;
+  size_t cur_nsub;
+  cur_nsub = preg->re_nsub++;
+
+  fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
+
+  /* The subexpression may be a null string.  */
+  if (token->type == OP_CLOSE_SUBEXP)
+    tree = NULL;
+  else
+    {
+      tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
+      if (BE (*err == REG_NOERROR && token->type != OP_CLOSE_SUBEXP, 0))
+       *err = REG_EPAREN;
+      if (BE (*err != REG_NOERROR, 0))
+       return NULL;
+    }
+
+  if (cur_nsub <= '9' - '1')
+    dfa->completed_bkref_map |= 1 << cur_nsub;
+
+  tree = create_tree (dfa, tree, NULL, SUBEXP);
+  if (BE (tree == NULL, 0))
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+  tree->token.opr.idx = cur_nsub;
+  return tree;
+}
+
+/* This function parse repetition operators like "*", "+", "{1,3}" etc.  */
+
+static bin_tree_t *
+parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
+             re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
+{
+  bin_tree_t *tree = NULL, *old_tree = NULL;
+  Idx i, start, end, start_idx = re_string_cur_idx (regexp);
+  re_token_t start_token = *token;
+
+  if (token->type == OP_OPEN_DUP_NUM)
+    {
+      end = 0;
+      start = fetch_number (regexp, token, syntax);
+      if (start == REG_MISSING)
+       {
+         if (token->type == CHARACTER && token->opr.c == ',')
+           start = 0; /* We treat "{,m}" as "{0,m}".  */
+         else
+           {
+             *err = REG_BADBR; /* <re>{} is invalid.  */
+             return NULL;
+           }
+       }
+      if (BE (start != REG_ERROR, 1))
+       {
+         /* We treat "{n}" as "{n,n}".  */
+         end = ((token->type == OP_CLOSE_DUP_NUM) ? start
+                : ((token->type == CHARACTER && token->opr.c == ',')
+                   ? fetch_number (regexp, token, syntax) : REG_ERROR));
+       }
+      if (BE (start == REG_ERROR || end == REG_ERROR, 0))
+       {
+         /* Invalid sequence.  */
+         if (BE (!(syntax & RE_INVALID_INTERVAL_ORD), 0))
+           {
+             if (token->type == END_OF_RE)
+               *err = REG_EBRACE;
+             else
+               *err = REG_BADBR;
+
+             return NULL;
+           }
+
+         /* If the syntax bit is set, rollback.  */
+         re_string_set_index (regexp, start_idx);
+         *token = start_token;
+         token->type = CHARACTER;
+         /* mb_partial and word_char bits should be already initialized by
+            peek_token.  */
+         return elem;
+       }
+
+      if (BE ((end != REG_MISSING && start > end)
+             || token->type != OP_CLOSE_DUP_NUM, 0))
+       {
+         /* First number greater than second.  */
+         *err = REG_BADBR;
+         return NULL;
+       }
+    }
+  else
+    {
+      start = (token->type == OP_DUP_PLUS) ? 1 : 0;
+      end = (token->type == OP_DUP_QUESTION) ? 1 : REG_MISSING;
+    }
+
+  fetch_token (token, regexp, syntax);
+
+  if (BE (elem == NULL, 0))
+    return NULL;
+  if (BE (start == 0 && end == 0, 0))
+    {
+      postorder (elem, free_tree, NULL);
+      return NULL;
+    }
+
+  /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
+  if (BE (start > 0, 0))
+    {
+      tree = elem;
+      for (i = 2; i <= start; ++i)
+       {
+         elem = duplicate_tree (elem, dfa);
+         tree = create_tree (dfa, tree, elem, CONCAT);
+         if (BE (elem == NULL || tree == NULL, 0))
+           goto parse_dup_op_espace;
+       }
+
+      if (start == end)
+       return tree;
+
+      /* Duplicate ELEM before it is marked optional.  */
+      elem = duplicate_tree (elem, dfa);
+      old_tree = tree;
+    }
+  else
+    old_tree = NULL;
+
+  if (elem->token.type == SUBEXP)
+    postorder (elem, mark_opt_subexp, (void *) (long) elem->token.opr.idx);
+
+  tree = create_tree (dfa, elem, NULL,
+                     (end == REG_MISSING ? OP_DUP_ASTERISK : OP_ALT));
+  if (BE (tree == NULL, 0))
+    goto parse_dup_op_espace;
+
+/* From gnulib's "intprops.h":
+   True if the arithmetic type T is signed.  */
+#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
+
+  /* This loop is actually executed only when end != REG_MISSING,
+     to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?...  We have
+     already created the start+1-th copy.  */
+  if (TYPE_SIGNED (Idx) || end != REG_MISSING)
+    for (i = start + 2; i <= end; ++i)
+      {
+       elem = duplicate_tree (elem, dfa);
+       tree = create_tree (dfa, tree, elem, CONCAT);
+       if (BE (elem == NULL || tree == NULL, 0))
+         goto parse_dup_op_espace;
+
+       tree = create_tree (dfa, tree, NULL, OP_ALT);
+       if (BE (tree == NULL, 0))
+         goto parse_dup_op_espace;
+      }
+
+  if (old_tree)
+    tree = create_tree (dfa, old_tree, tree, CONCAT);
+
+  return tree;
+
+ parse_dup_op_espace:
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* Size of the names for collating symbol/equivalence_class/character_class.
+   I'm not sure, but maybe enough.  */
+#define BRACKET_NAME_BUF_SIZE 32
+
+#ifndef _LIBC
+  /* Local function for parse_bracket_exp only used in case of NOT _LIBC.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+static reg_errcode_t
+internal_function
+# ifdef RE_ENABLE_I18N
+build_range_exp (const reg_syntax_t syntax,
+                 bitset_t sbcset,
+                 re_charset_t *mbcset,
+                 Idx *range_alloc,
+                 const bracket_elem_t *start_elem,
+                 const bracket_elem_t *end_elem)
+# else /* not RE_ENABLE_I18N */
+build_range_exp (const reg_syntax_t syntax,
+                 bitset_t sbcset,
+                 const bracket_elem_t *start_elem,
+                 const bracket_elem_t *end_elem)
+# endif /* not RE_ENABLE_I18N */
+{
+  unsigned int start_ch, end_ch;
+  /* Equivalence Classes and Character Classes can't be a range start/end.  */
+  if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+         || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+         0))
+    return REG_ERANGE;
+
+  /* We can handle no multi character collating elements without libc
+     support.  */
+  if (BE ((start_elem->type == COLL_SYM
+          && strlen ((char *) start_elem->opr.name) > 1)
+         || (end_elem->type == COLL_SYM
+             && strlen ((char *) end_elem->opr.name) > 1), 0))
+    return REG_ECOLLATE;
+
+# ifdef RE_ENABLE_I18N
+  {
+    wchar_t wc;
+    wint_t start_wc;
+    wint_t end_wc;
+    wchar_t cmp_buf[6] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+
+    start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
+               : ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+                  : 0));
+    end_ch = ((end_elem->type == SB_CHAR) ? end_elem->opr.ch
+             : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+                : 0));
+    start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
+               ? __btowc (start_ch) : start_elem->opr.wch);
+    end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
+             ? __btowc (end_ch) : end_elem->opr.wch);
+    if (start_wc == WEOF || end_wc == WEOF)
+      return REG_ECOLLATE;
+    cmp_buf[0] = start_wc;
+    cmp_buf[4] = end_wc;
+
+    if (BE ((syntax & RE_NO_EMPTY_RANGES)
+            && wcscoll (cmp_buf, cmp_buf + 4) > 0, 0))
+      return REG_ERANGE;
+
+    /* Got valid collation sequence values, add them as a new entry.
+       However, for !_LIBC we have no collation elements: if the
+       character set is single byte, the single byte character set
+       that we build below suffices.  parse_bracket_exp passes
+       no MBCSET if dfa->mb_cur_max == 1.  */
+    if (mbcset)
+      {
+       /* Check the space of the arrays.  */
+       if (BE (*range_alloc == mbcset->nranges, 0))
+         {
+           /* There is not enough space, need realloc.  */
+           wchar_t *new_array_start, *new_array_end;
+           Idx new_nranges;
+
+           /* +1 in case of mbcset->nranges is 0.  */
+           new_nranges = 2 * mbcset->nranges + 1;
+           /* Use realloc since mbcset->range_starts and mbcset->range_ends
+              are NULL if *range_alloc == 0.  */
+           new_array_start = re_realloc (mbcset->range_starts, wchar_t,
+                                         new_nranges);
+           new_array_end = re_realloc (mbcset->range_ends, wchar_t,
+                                       new_nranges);
+
+           if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+             return REG_ESPACE;
+
+           mbcset->range_starts = new_array_start;
+           mbcset->range_ends = new_array_end;
+           *range_alloc = new_nranges;
+         }
+
+       mbcset->range_starts[mbcset->nranges] = start_wc;
+       mbcset->range_ends[mbcset->nranges++] = end_wc;
+      }
+
+    /* Build the table for single byte characters.  */
+    for (wc = 0; wc < SBC_MAX; ++wc)
+      {
+       cmp_buf[2] = wc;
+       if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+           && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+         bitset_set (sbcset, wc);
+      }
+  }
+# else /* not RE_ENABLE_I18N */
+  {
+    unsigned int ch;
+    start_ch = ((start_elem->type == SB_CHAR ) ? start_elem->opr.ch
+               : ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
+                  : 0));
+    end_ch = ((end_elem->type == SB_CHAR ) ? end_elem->opr.ch
+             : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
+                : 0));
+    if (start_ch > end_ch)
+      return REG_ERANGE;
+    /* Build the table for single byte characters.  */
+    for (ch = 0; ch < SBC_MAX; ++ch)
+      if (start_ch <= ch  && ch <= end_ch)
+       bitset_set (sbcset, ch);
+  }
+# endif /* not RE_ENABLE_I18N */
+  return REG_NOERROR;
+}
+#endif /* not _LIBC */
+
+#ifndef _LIBC
+/* Helper function for parse_bracket_exp only used in case of NOT _LIBC..
+   Build the collating element which is represented by NAME.
+   The result are written to MBCSET and SBCSET.
+   COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+   pointer argument since we may update it.  */
+
+static reg_errcode_t
+internal_function
+build_collating_symbol (bitset_t sbcset,
+# ifdef RE_ENABLE_I18N
+                       re_charset_t *mbcset, Idx *coll_sym_alloc,
+# endif
+                       const unsigned char *name)
+{
+  size_t name_len = strlen ((const char *) name);
+  if (BE (name_len != 1, 0))
+    return REG_ECOLLATE;
+  else
+    {
+      bitset_set (sbcset, name[0]);
+      return REG_NOERROR;
+    }
+}
+#endif /* not _LIBC */
+
+/* This function parse bracket expression like "[abc]", "[a-c]",
+   "[[.a-a.]]" etc.  */
+
+static bin_tree_t *
+parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
+                  reg_syntax_t syntax, reg_errcode_t *err)
+{
+#ifdef _LIBC
+  const unsigned char *collseqmb;
+  const char *collseqwc;
+  uint32_t nrules;
+  int32_t table_size;
+  const int32_t *symb_table;
+  const unsigned char *extra;
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Seek the collating symbol entry correspondings to NAME.
+     Return the index of the symbol in the SYMB_TABLE.  */
+
+  auto inline int32_t
+  __attribute ((always_inline))
+  seek_collating_symbol_entry (name, name_len)
+        const unsigned char *name;
+        size_t name_len;
+    {
+      int32_t hash = elem_hash ((const char *) name, name_len);
+      int32_t elem = hash % table_size;
+      if (symb_table[2 * elem] != 0)
+       {
+         int32_t second = hash % (table_size - 2) + 1;
+
+         do
+           {
+             /* First compare the hashing value.  */
+             if (symb_table[2 * elem] == hash
+                 /* Compare the length of the name.  */
+                 && name_len == extra[symb_table[2 * elem + 1]]
+                 /* Compare the name.  */
+                 && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
+                            name_len) == 0)
+               {
+                 /* Yep, this is the entry.  */
+                 break;
+               }
+
+             /* Next entry.  */
+             elem += second;
+           }
+         while (symb_table[2 * elem] != 0);
+       }
+      return elem;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environment.
+     Look up the collation sequence value of BR_ELEM.
+     Return the value if succeeded, UINT_MAX otherwise.  */
+
+  auto inline unsigned int
+  __attribute ((always_inline))
+  lookup_collation_sequence_value (br_elem)
+        bracket_elem_t *br_elem;
+    {
+      if (br_elem->type == SB_CHAR)
+       {
+         /*
+         if (MB_CUR_MAX == 1)
+         */
+         if (nrules == 0)
+           return collseqmb[br_elem->opr.ch];
+         else
+           {
+             wint_t wc = __btowc (br_elem->opr.ch);
+             return __collseq_table_lookup (collseqwc, wc);
+           }
+       }
+      else if (br_elem->type == MB_CHAR)
+       {
+         if (nrules != 0)
+           return __collseq_table_lookup (collseqwc, br_elem->opr.wch);
+       }
+      else if (br_elem->type == COLL_SYM)
+       {
+         size_t sym_name_len = strlen ((char *) br_elem->opr.name);
+         if (nrules != 0)
+           {
+             int32_t elem, idx;
+             elem = seek_collating_symbol_entry (br_elem->opr.name,
+                                                 sym_name_len);
+             if (symb_table[2 * elem] != 0)
+               {
+                 /* We found the entry.  */
+                 idx = symb_table[2 * elem + 1];
+                 /* Skip the name of collating element name.  */
+                 idx += 1 + extra[idx];
+                 /* Skip the byte sequence of the collating element.  */
+                 idx += 1 + extra[idx];
+                 /* Adjust for the alignment.  */
+                 idx = (idx + 3) & ~3;
+                 /* Skip the multibyte collation sequence value.  */
+                 idx += sizeof (unsigned int);
+                 /* Skip the wide char sequence of the collating element.  */
+                 idx += sizeof (unsigned int) *
+                   (1 + *(unsigned int *) (extra + idx));
+                 /* Return the collation sequence value.  */
+                 return *(unsigned int *) (extra + idx);
+               }
+             else if (symb_table[2 * elem] == 0 && sym_name_len == 1)
+               {
+                 /* No valid character.  Match it as a single byte
+                    character.  */
+                 return collseqmb[br_elem->opr.name[0]];
+               }
+           }
+         else if (sym_name_len == 1)
+           return collseqmb[br_elem->opr.name[0]];
+       }
+      return UINT_MAX;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the range expression which starts from START_ELEM, and ends
+     at END_ELEM.  The result are written to MBCSET and SBCSET.
+     RANGE_ALLOC is the allocated size of mbcset->range_starts, and
+     mbcset->range_ends, is a pointer argument sinse we may
+     update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
+        re_charset_t *mbcset;
+        Idx *range_alloc;
+        bitset_t sbcset;
+        bracket_elem_t *start_elem, *end_elem;
+    {
+      unsigned int ch;
+      uint32_t start_collseq;
+      uint32_t end_collseq;
+
+      /* Equivalence Classes and Character Classes can't be a range
+        start/end.  */
+      if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
+             || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
+             0))
+       return REG_ERANGE;
+
+      start_collseq = lookup_collation_sequence_value (start_elem);
+      end_collseq = lookup_collation_sequence_value (end_elem);
+      /* Check start/end collation sequence values.  */
+      if (BE (start_collseq == UINT_MAX || end_collseq == UINT_MAX, 0))
+       return REG_ECOLLATE;
+      if (BE ((syntax & RE_NO_EMPTY_RANGES) && start_collseq > end_collseq, 0))
+       return REG_ERANGE;
+
+      /* Got valid collation sequence values, add them as a new entry.
+        However, if we have no collation elements, and the character set
+        is single byte, the single byte character set that we
+        build below suffices. */
+      if (nrules > 0 || dfa->mb_cur_max > 1)
+       {
+         /* Check the space of the arrays.  */
+         if (BE (*range_alloc == mbcset->nranges, 0))
+           {
+             /* There is not enough space, need realloc.  */
+             uint32_t *new_array_start;
+             uint32_t *new_array_end;
+             Idx new_nranges;
+
+             /* +1 in case of mbcset->nranges is 0.  */
+             new_nranges = 2 * mbcset->nranges + 1;
+             new_array_start = re_realloc (mbcset->range_starts, uint32_t,
+                                           new_nranges);
+             new_array_end = re_realloc (mbcset->range_ends, uint32_t,
+                                         new_nranges);
+
+             if (BE (new_array_start == NULL || new_array_end == NULL, 0))
+               return REG_ESPACE;
+
+             mbcset->range_starts = new_array_start;
+             mbcset->range_ends = new_array_end;
+             *range_alloc = new_nranges;
+           }
+
+         mbcset->range_starts[mbcset->nranges] = start_collseq;
+         mbcset->range_ends[mbcset->nranges++] = end_collseq;
+       }
+
+      /* Build the table for single byte characters.  */
+      for (ch = 0; ch < SBC_MAX; ch++)
+       {
+         uint32_t ch_collseq;
+         /*
+         if (MB_CUR_MAX == 1)
+         */
+         if (nrules == 0)
+           ch_collseq = collseqmb[ch];
+         else
+           ch_collseq = __collseq_table_lookup (collseqwc, __btowc (ch));
+         if (start_collseq <= ch_collseq && ch_collseq <= end_collseq)
+           bitset_set (sbcset, ch);
+       }
+      return REG_NOERROR;
+    }
+
+  /* Local function for parse_bracket_exp used in _LIBC environement.
+     Build the collating element which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
+     pointer argument sinse we may update it.  */
+
+  auto inline reg_errcode_t
+  __attribute ((always_inline))
+  build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
+        re_charset_t *mbcset;
+        Idx *coll_sym_alloc;
+        bitset_t sbcset;
+        const unsigned char *name;
+    {
+      int32_t elem, idx;
+      size_t name_len = strlen ((const char *) name);
+      if (nrules != 0)
+       {
+         elem = seek_collating_symbol_entry (name, name_len);
+         if (symb_table[2 * elem] != 0)
+           {
+             /* We found the entry.  */
+             idx = symb_table[2 * elem + 1];
+             /* Skip the name of collating element name.  */
+             idx += 1 + extra[idx];
+           }
+         else if (symb_table[2 * elem] == 0 && name_len == 1)
+           {
+             /* No valid character, treat it as a normal
+                character.  */
+             bitset_set (sbcset, name[0]);
+             return REG_NOERROR;
+           }
+         else
+           return REG_ECOLLATE;
+
+         /* Got valid collation sequence, add it as a new entry.  */
+         /* Check the space of the arrays.  */
+         if (BE (*coll_sym_alloc == mbcset->ncoll_syms, 0))
+           {
+             /* Not enough, realloc it.  */
+             /* +1 in case of mbcset->ncoll_syms is 0.  */
+             Idx new_coll_sym_alloc = 2 * mbcset->ncoll_syms + 1;
+             /* Use realloc since mbcset->coll_syms is NULL
+                if *alloc == 0.  */
+             int32_t *new_coll_syms = re_realloc (mbcset->coll_syms, int32_t,
+                                                  new_coll_sym_alloc);
+             if (BE (new_coll_syms == NULL, 0))
+               return REG_ESPACE;
+             mbcset->coll_syms = new_coll_syms;
+             *coll_sym_alloc = new_coll_sym_alloc;
+           }
+         mbcset->coll_syms[mbcset->ncoll_syms++] = idx;
+         return REG_NOERROR;
+       }
+      else
+       {
+         if (BE (name_len != 1, 0))
+           return REG_ECOLLATE;
+         else
+           {
+             bitset_set (sbcset, name[0]);
+             return REG_NOERROR;
+           }
+       }
+    }
+#endif
+
+  re_token_t br_token;
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  Idx coll_sym_alloc = 0, range_alloc = 0, mbchar_alloc = 0;
+  Idx equiv_class_alloc = 0, char_class_alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  bool non_match = false;
+  bin_tree_t *work_tree;
+  int token_len;
+  bool first_round = true;
+#ifdef _LIBC
+  collseqmb = (const unsigned char *)
+    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+  nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules)
+    {
+      /*
+      if (MB_CUR_MAX > 1)
+      */
+      collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+      table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
+      symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+                                                 _NL_COLLATE_SYMB_TABLEMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+                                                  _NL_COLLATE_SYMB_EXTRAMB);
+    }
+#endif
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else
+  if (BE (sbcset == NULL, 0))
+#endif /* RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  token_len = peek_token_bracket (token, regexp, syntax);
+  if (BE (token->type == END_OF_RE, 0))
+    {
+      *err = REG_BADPAT;
+      goto parse_bracket_exp_free_return;
+    }
+  if (token->type == OP_NON_MATCH_LIST)
+    {
+#ifdef RE_ENABLE_I18N
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+      non_match = true;
+      if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
+       bitset_set (sbcset, '\n');
+      re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+      if (BE (token->type == END_OF_RE, 0))
+       {
+         *err = REG_BADPAT;
+         goto parse_bracket_exp_free_return;
+       }
+    }
+
+  /* We treat the first ']' as a normal character.  */
+  if (token->type == OP_CLOSE_BRACKET)
+    token->type = CHARACTER;
+
+  while (1)
+    {
+      bracket_elem_t start_elem, end_elem;
+      unsigned char start_name_buf[BRACKET_NAME_BUF_SIZE];
+      unsigned char end_name_buf[BRACKET_NAME_BUF_SIZE];
+      reg_errcode_t ret;
+      int token_len2 = 0;
+      bool is_range_exp = false;
+      re_token_t token2;
+
+      start_elem.opr.name = start_name_buf;
+      ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
+                                  syntax, first_round);
+      if (BE (ret != REG_NOERROR, 0))
+       {
+         *err = ret;
+         goto parse_bracket_exp_free_return;
+       }
+      first_round = false;
+
+      /* Get information about the next token.  We need it in any case.  */
+      token_len = peek_token_bracket (token, regexp, syntax);
+
+      /* Do not check for ranges if we know they are not allowed.  */
+      if (start_elem.type != CHAR_CLASS && start_elem.type != EQUIV_CLASS)
+       {
+         if (BE (token->type == END_OF_RE, 0))
+           {
+             *err = REG_EBRACK;
+             goto parse_bracket_exp_free_return;
+           }
+         if (token->type == OP_CHARSET_RANGE)
+           {
+             re_string_skip_bytes (regexp, token_len); /* Skip '-'.  */
+             token_len2 = peek_token_bracket (&token2, regexp, syntax);
+             if (BE (token2.type == END_OF_RE, 0))
+               {
+                 *err = REG_EBRACK;
+                 goto parse_bracket_exp_free_return;
+               }
+             if (token2.type == OP_CLOSE_BRACKET)
+               {
+                 /* We treat the last '-' as a normal character.  */
+                 re_string_skip_bytes (regexp, -token_len);
+                 token->type = CHARACTER;
+               }
+             else
+               is_range_exp = true;
+           }
+       }
+
+      if (is_range_exp == true)
+       {
+         end_elem.opr.name = end_name_buf;
+         ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
+                                      dfa, syntax, true);
+         if (BE (ret != REG_NOERROR, 0))
+           {
+             *err = ret;
+             goto parse_bracket_exp_free_return;
+           }
+
+         token_len = peek_token_bracket (token, regexp, syntax);
+
+#ifdef _LIBC
+         *err = build_range_exp (sbcset, mbcset, &range_alloc,
+                                 &start_elem, &end_elem);
+#else
+# ifdef RE_ENABLE_I18N
+         *err = build_range_exp (syntax, sbcset,
+                                 dfa->mb_cur_max > 1 ? mbcset : NULL,
+                                 &range_alloc, &start_elem, &end_elem);
+# else
+         *err = build_range_exp (syntax, sbcset, &start_elem, &end_elem);
+# endif
+#endif /* RE_ENABLE_I18N */
+         if (BE (*err != REG_NOERROR, 0))
+           goto parse_bracket_exp_free_return;
+       }
+      else
+       {
+         switch (start_elem.type)
+           {
+           case SB_CHAR:
+             bitset_set (sbcset, start_elem.opr.ch);
+             break;
+#ifdef RE_ENABLE_I18N
+           case MB_CHAR:
+             /* Check whether the array has enough space.  */
+             if (BE (mbchar_alloc == mbcset->nmbchars, 0))
+               {
+                 wchar_t *new_mbchars;
+                 /* Not enough, realloc it.  */
+                 /* +1 in case of mbcset->nmbchars is 0.  */
+                 mbchar_alloc = 2 * mbcset->nmbchars + 1;
+                 /* Use realloc since array is NULL if *alloc == 0.  */
+                 new_mbchars = re_realloc (mbcset->mbchars, wchar_t,
+                                           mbchar_alloc);
+                 if (BE (new_mbchars == NULL, 0))
+                   goto parse_bracket_exp_espace;
+                 mbcset->mbchars = new_mbchars;
+               }
+             mbcset->mbchars[mbcset->nmbchars++] = start_elem.opr.wch;
+             break;
+#endif /* RE_ENABLE_I18N */
+           case EQUIV_CLASS:
+             *err = build_equiv_class (sbcset,
+#ifdef RE_ENABLE_I18N
+                                       mbcset, &equiv_class_alloc,
+#endif /* RE_ENABLE_I18N */
+                                       start_elem.opr.name);
+             if (BE (*err != REG_NOERROR, 0))
+               goto parse_bracket_exp_free_return;
+             break;
+           case COLL_SYM:
+             *err = build_collating_symbol (sbcset,
+#ifdef RE_ENABLE_I18N
+                                            mbcset, &coll_sym_alloc,
+#endif /* RE_ENABLE_I18N */
+                                            start_elem.opr.name);
+             if (BE (*err != REG_NOERROR, 0))
+               goto parse_bracket_exp_free_return;
+             break;
+           case CHAR_CLASS:
+             *err = build_charclass (regexp->trans, sbcset,
+#ifdef RE_ENABLE_I18N
+                                     mbcset, &char_class_alloc,
+#endif /* RE_ENABLE_I18N */
+                                     start_elem.opr.name, syntax);
+             if (BE (*err != REG_NOERROR, 0))
+              goto parse_bracket_exp_free_return;
+             break;
+           default:
+             assert (0);
+             break;
+           }
+       }
+      if (BE (token->type == END_OF_RE, 0))
+       {
+         *err = REG_EBRACK;
+         goto parse_bracket_exp_free_return;
+       }
+      if (token->type == OP_CLOSE_BRACKET)
+       break;
+    }
+
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+
+  if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
+      || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
+                                                    || mbcset->non_match)))
+    {
+      bin_tree_t *mbc_tree;
+      int sbc_idx;
+      /* Build a tree for complex bracket.  */
+      dfa->has_mb_node = 1;
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+       goto parse_bracket_exp_espace;
+      for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
+       if (sbcset[sbc_idx])
+         break;
+      /* If there are no bits set in sbcset, there is no point
+        of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
+      if (sbc_idx < BITSET_WORDS)
+       {
+         /* Build a tree for simple bracket.  */
+         br_token.type = SIMPLE_BRACKET;
+         br_token.opr.sbcset = sbcset;
+         work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+         if (BE (work_tree == NULL, 0))
+           goto parse_bracket_exp_espace;
+
+         /* Then join them by ALT node.  */
+         work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
+         if (BE (work_tree == NULL, 0))
+           goto parse_bracket_exp_espace;
+       }
+      else
+       {
+         re_free (sbcset);
+         work_tree = mbc_tree;
+       }
+    }
+  else
+#endif /* not RE_ENABLE_I18N */
+    {
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif
+      /* Build a tree for simple bracket.  */
+      br_token.type = SIMPLE_BRACKET;
+      br_token.opr.sbcset = sbcset;
+      work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (work_tree == NULL, 0))
+       goto parse_bracket_exp_espace;
+    }
+  return work_tree;
+
+ parse_bracket_exp_espace:
+  *err = REG_ESPACE;
+ parse_bracket_exp_free_return:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  return NULL;
+}
+
+/* Parse an element in the bracket expression.  */
+
+static reg_errcode_t
+parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
+                      re_token_t *token, int token_len, re_dfa_t *dfa,
+                      reg_syntax_t syntax, bool accept_hyphen)
+{
+#ifdef RE_ENABLE_I18N
+  int cur_char_size;
+  cur_char_size = re_string_char_size_at (regexp, re_string_cur_idx (regexp));
+  if (cur_char_size > 1)
+    {
+      elem->type = MB_CHAR;
+      elem->opr.wch = re_string_wchar_at (regexp, re_string_cur_idx (regexp));
+      re_string_skip_bytes (regexp, cur_char_size);
+      return REG_NOERROR;
+    }
+#endif /* RE_ENABLE_I18N */
+  re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
+  if (token->type == OP_OPEN_COLL_ELEM || token->type == OP_OPEN_CHAR_CLASS
+      || token->type == OP_OPEN_EQUIV_CLASS)
+    return parse_bracket_symbol (elem, regexp, token);
+  if (BE (token->type == OP_CHARSET_RANGE, 0) && !accept_hyphen)
+    {
+      /* A '-' must only appear as anything but a range indicator before
+        the closing bracket.  Everything else is an error.  */
+      re_token_t token2;
+      (void) peek_token_bracket (&token2, regexp, syntax);
+      if (token2.type != OP_CLOSE_BRACKET)
+       /* The actual error value is not standardized since this whole
+          case is undefined.  But ERANGE makes good sense.  */
+       return REG_ERANGE;
+    }
+  elem->type = SB_CHAR;
+  elem->opr.ch = token->opr.c;
+  return REG_NOERROR;
+}
+
+/* Parse a bracket symbol in the bracket expression.  Bracket symbols are
+   such as [:<character_class>:], [.<collating_element>.], and
+   [=<equivalent_class>=].  */
+
+static reg_errcode_t
+parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
+                     re_token_t *token)
+{
+  unsigned char ch, delim = token->opr.c;
+  int i = 0;
+  if (re_string_eoi(regexp))
+    return REG_EBRACK;
+  for (;; ++i)
+    {
+      if (i >= BRACKET_NAME_BUF_SIZE)
+       return REG_EBRACK;
+      if (token->type == OP_OPEN_CHAR_CLASS)
+       ch = re_string_fetch_byte_case (regexp);
+      else
+       ch = re_string_fetch_byte (regexp);
+      if (re_string_eoi(regexp))
+       return REG_EBRACK;
+      if (ch == delim && re_string_peek_byte (regexp, 0) == ']')
+       break;
+      elem->opr.name[i] = ch;
+    }
+  re_string_skip_bytes (regexp, 1);
+  elem->opr.name[i] = '\0';
+  switch (token->type)
+    {
+    case OP_OPEN_COLL_ELEM:
+      elem->type = COLL_SYM;
+      break;
+    case OP_OPEN_EQUIV_CLASS:
+      elem->type = EQUIV_CLASS;
+      break;
+    case OP_OPEN_CHAR_CLASS:
+      elem->type = CHAR_CLASS;
+      break;
+    default:
+      break;
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the equivalence class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     EQUIV_CLASS_ALLOC is the allocated size of mbcset->equiv_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_equiv_class (bitset_t sbcset, re_charset_t *mbcset,
+                  Idx *equiv_class_alloc, const unsigned char *name)
+#else /* not RE_ENABLE_I18N */
+build_equiv_class (bitset_t sbcset, const unsigned char *name)
+#endif /* not RE_ENABLE_I18N */
+{
+#ifdef _LIBC
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules != 0)
+    {
+      const int32_t *table, *indirect;
+      const unsigned char *weights, *extra, *cp;
+      unsigned char char_buf[2];
+      int32_t idx1, idx2;
+      unsigned int ch;
+      size_t len;
+      /* This #include defines a local function!  */
+# include <locale/weight.h>
+      /* Calculate the index for equivalence class.  */
+      cp = name;
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      weights = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+                                              _NL_COLLATE_WEIGHTMB);
+      extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
+                                                  _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+                                               _NL_COLLATE_INDIRECTMB);
+      idx1 = findidx (&cp);
+      if (BE (idx1 == 0 || cp < name + strlen ((const char *) name), 0))
+       /* This isn't a valid character.  */
+       return REG_ECOLLATE;
+
+      /* Build single byte matcing table for this equivalence class.  */
+      char_buf[1] = (unsigned char) '\0';
+      len = weights[idx1 & 0xffffff];
+      for (ch = 0; ch < SBC_MAX; ++ch)
+       {
+         char_buf[0] = ch;
+         cp = char_buf;
+         idx2 = findidx (&cp);
+/*
+         idx2 = table[ch];
+*/
+         if (idx2 == 0)
+           /* This isn't a valid character.  */
+           continue;
+         /* Compare only if the length matches and the collation rule
+            index is the same.  */
+         if (len == weights[idx2 & 0xffffff] && (idx1 >> 24) == (idx2 >> 24))
+           {
+             int cnt = 0;
+
+             while (cnt <= len &&
+                    weights[(idx1 & 0xffffff) + 1 + cnt]
+                    == weights[(idx2 & 0xffffff) + 1 + cnt])
+               ++cnt;
+
+             if (cnt > len)
+               bitset_set (sbcset, ch);
+           }
+       }
+      /* Check whether the array has enough space.  */
+      if (BE (*equiv_class_alloc == mbcset->nequiv_classes, 0))
+       {
+         /* Not enough, realloc it.  */
+         /* +1 in case of mbcset->nequiv_classes is 0.  */
+         Idx new_equiv_class_alloc = 2 * mbcset->nequiv_classes + 1;
+         /* Use realloc since the array is NULL if *alloc == 0.  */
+         int32_t *new_equiv_classes = re_realloc (mbcset->equiv_classes,
+                                                  int32_t,
+                                                  new_equiv_class_alloc);
+         if (BE (new_equiv_classes == NULL, 0))
+           return REG_ESPACE;
+         mbcset->equiv_classes = new_equiv_classes;
+         *equiv_class_alloc = new_equiv_class_alloc;
+       }
+      mbcset->equiv_classes[mbcset->nequiv_classes++] = idx1;
+    }
+  else
+#endif /* _LIBC */
+    {
+      if (BE (strlen ((const char *) name) != 1, 0))
+       return REG_ECOLLATE;
+      bitset_set (sbcset, *name);
+    }
+  return REG_NOERROR;
+}
+
+  /* Helper function for parse_bracket_exp.
+     Build the character class which is represented by NAME.
+     The result are written to MBCSET and SBCSET.
+     CHAR_CLASS_ALLOC is the allocated size of mbcset->char_classes,
+     is a pointer argument sinse we may update it.  */
+
+static reg_errcode_t
+#ifdef RE_ENABLE_I18N
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+                re_charset_t *mbcset, Idx *char_class_alloc,
+                const unsigned char *class_name, reg_syntax_t syntax)
+#else /* not RE_ENABLE_I18N */
+build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
+                const unsigned char *class_name, reg_syntax_t syntax)
+#endif /* not RE_ENABLE_I18N */
+{
+  int i;
+  const char *name = (const char *) class_name;
+
+  /* In case of REG_ICASE "upper" and "lower" match the both of
+     upper and lower cases.  */
+  if ((syntax & RE_ICASE)
+      && (strcmp (name, "upper") == 0 || strcmp (name, "lower") == 0))
+    name = "alpha";
+
+#ifdef RE_ENABLE_I18N
+  /* Check the space of the arrays.  */
+  if (BE (*char_class_alloc == mbcset->nchar_classes, 0))
+    {
+      /* Not enough, realloc it.  */
+      /* +1 in case of mbcset->nchar_classes is 0.  */
+      Idx new_char_class_alloc = 2 * mbcset->nchar_classes + 1;
+      /* Use realloc since array is NULL if *alloc == 0.  */
+      wctype_t *new_char_classes = re_realloc (mbcset->char_classes, wctype_t,
+                                              new_char_class_alloc);
+      if (BE (new_char_classes == NULL, 0))
+       return REG_ESPACE;
+      mbcset->char_classes = new_char_classes;
+      *char_class_alloc = new_char_class_alloc;
+    }
+  mbcset->char_classes[mbcset->nchar_classes++] = __wctype (name);
+#endif /* RE_ENABLE_I18N */
+
+#define BUILD_CHARCLASS_LOOP(ctype_func)       \
+  do {                                         \
+    if (BE (trans != NULL, 0))                 \
+      {                                                \
+       for (i = 0; i < SBC_MAX; ++i)           \
+         if (ctype_func (i))                   \
+           bitset_set (sbcset, trans[i]);      \
+      }                                                \
+    else                                       \
+      {                                                \
+       for (i = 0; i < SBC_MAX; ++i)           \
+         if (ctype_func (i))                   \
+           bitset_set (sbcset, i);             \
+      }                                                \
+  } while (0)
+
+  if (strcmp (name, "alnum") == 0)
+    BUILD_CHARCLASS_LOOP (isalnum);
+  else if (strcmp (name, "cntrl") == 0)
+    BUILD_CHARCLASS_LOOP (iscntrl);
+  else if (strcmp (name, "lower") == 0)
+    BUILD_CHARCLASS_LOOP (islower);
+  else if (strcmp (name, "space") == 0)
+    BUILD_CHARCLASS_LOOP (isspace);
+  else if (strcmp (name, "alpha") == 0)
+    BUILD_CHARCLASS_LOOP (isalpha);
+  else if (strcmp (name, "digit") == 0)
+    BUILD_CHARCLASS_LOOP (isdigit);
+  else if (strcmp (name, "print") == 0)
+    BUILD_CHARCLASS_LOOP (isprint);
+  else if (strcmp (name, "upper") == 0)
+    BUILD_CHARCLASS_LOOP (isupper);
+  else if (strcmp (name, "blank") == 0)
+    BUILD_CHARCLASS_LOOP (isblank);
+  else if (strcmp (name, "graph") == 0)
+    BUILD_CHARCLASS_LOOP (isgraph);
+  else if (strcmp (name, "punct") == 0)
+    BUILD_CHARCLASS_LOOP (ispunct);
+  else if (strcmp (name, "xdigit") == 0)
+    BUILD_CHARCLASS_LOOP (isxdigit);
+  else
+    return REG_ECTYPE;
+
+  return REG_NOERROR;
+}
+
+static bin_tree_t *
+build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
+                   const unsigned char *class_name,
+                   const unsigned char *extra, bool non_match,
+                   reg_errcode_t *err)
+{
+  re_bitset_ptr_t sbcset;
+#ifdef RE_ENABLE_I18N
+  re_charset_t *mbcset;
+  Idx alloc = 0;
+#endif /* not RE_ENABLE_I18N */
+  reg_errcode_t ret;
+  re_token_t br_token;
+  bin_tree_t *tree;
+
+  sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
+#ifdef RE_ENABLE_I18N
+  mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
+#endif /* RE_ENABLE_I18N */
+
+#ifdef RE_ENABLE_I18N
+  if (BE (sbcset == NULL || mbcset == NULL, 0))
+#else /* not RE_ENABLE_I18N */
+  if (BE (sbcset == NULL, 0))
+#endif /* not RE_ENABLE_I18N */
+    {
+      *err = REG_ESPACE;
+      return NULL;
+    }
+
+  if (non_match)
+    {
+#ifdef RE_ENABLE_I18N
+      mbcset->non_match = 1;
+#endif /* not RE_ENABLE_I18N */
+    }
+
+  /* We don't care the syntax in this case.  */
+  ret = build_charclass (trans, sbcset,
+#ifdef RE_ENABLE_I18N
+                        mbcset, &alloc,
+#endif /* RE_ENABLE_I18N */
+                        class_name, 0);
+
+  if (BE (ret != REG_NOERROR, 0))
+    {
+      re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+      free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+      *err = ret;
+      return NULL;
+    }
+  /* \w match '_' also.  */
+  for (; *extra; extra++)
+    bitset_set (sbcset, *extra);
+
+  /* If it is non-matching list.  */
+  if (non_match)
+    bitset_not (sbcset);
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure only single byte characters are set.  */
+  if (dfa->mb_cur_max > 1)
+    bitset_mask (sbcset, dfa->sb_char);
+#endif
+
+  /* Build a tree for simple bracket.  */
+  br_token.type = SIMPLE_BRACKET;
+  br_token.opr.sbcset = sbcset;
+  tree = create_token_tree (dfa, NULL, NULL, &br_token);
+  if (BE (tree == NULL, 0))
+    goto build_word_op_espace;
+
+#ifdef RE_ENABLE_I18N
+  if (dfa->mb_cur_max > 1)
+    {
+      bin_tree_t *mbc_tree;
+      /* Build a tree for complex bracket.  */
+      br_token.type = COMPLEX_BRACKET;
+      br_token.opr.mbcset = mbcset;
+      dfa->has_mb_node = 1;
+      mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
+      if (BE (mbc_tree == NULL, 0))
+       goto build_word_op_espace;
+      /* Then join them by ALT node.  */
+      tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
+      if (BE (mbc_tree != NULL, 1))
+       return tree;
+    }
+  else
+    {
+      free_charset (mbcset);
+      return tree;
+    }
+#else /* not RE_ENABLE_I18N */
+  return tree;
+#endif /* not RE_ENABLE_I18N */
+
+ build_word_op_espace:
+  re_free (sbcset);
+#ifdef RE_ENABLE_I18N
+  free_charset (mbcset);
+#endif /* RE_ENABLE_I18N */
+  *err = REG_ESPACE;
+  return NULL;
+}
+
+/* This is intended for the expressions like "a{1,3}".
+   Fetch a number from 'input', and return the number.
+   Return REG_MISSING if the number field is empty like "{,1}".
+   Return REG_ERROR if an error occurred.  */
+
+static Idx
+fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
+{
+  Idx num = REG_MISSING;
+  unsigned char c;
+  while (1)
+    {
+      fetch_token (token, input, syntax);
+      c = token->opr.c;
+      if (BE (token->type == END_OF_RE, 0))
+       return REG_ERROR;
+      if (token->type == OP_CLOSE_DUP_NUM || c == ',')
+       break;
+      num = ((token->type != CHARACTER || c < '0' || '9' < c
+             || num == REG_ERROR)
+            ? REG_ERROR
+            : ((num == REG_MISSING) ? c - '0' : num * 10 + c - '0'));
+      num = (num > RE_DUP_MAX) ? REG_ERROR : num;
+    }
+  return num;
+}
+
+#ifdef RE_ENABLE_I18N
+static void
+free_charset (re_charset_t *cset)
+{
+  re_free (cset->mbchars);
+# ifdef _LIBC
+  re_free (cset->coll_syms);
+  re_free (cset->equiv_classes);
+  re_free (cset->range_starts);
+  re_free (cset->range_ends);
+# endif
+  re_free (cset->char_classes);
+  re_free (cset);
+}
+#endif /* RE_ENABLE_I18N */
+
+/* Functions for binary tree operation.  */
+
+/* Create a tree node.  */
+
+static bin_tree_t *
+create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+            re_token_type_t type)
+{
+  re_token_t t;
+  t.type = type;
+  return create_token_tree (dfa, left, right, &t);
+}
+
+static bin_tree_t *
+create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
+                  const re_token_t *token)
+{
+  bin_tree_t *tree;
+  if (BE (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE, 0))
+    {
+      bin_tree_storage_t *storage = re_malloc (bin_tree_storage_t, 1);
+
+      if (storage == NULL)
+       return NULL;
+      storage->next = dfa->str_tree_storage;
+      dfa->str_tree_storage = storage;
+      dfa->str_tree_storage_idx = 0;
+    }
+  tree = &dfa->str_tree_storage->data[dfa->str_tree_storage_idx++];
+
+  tree->parent = NULL;
+  tree->left = left;
+  tree->right = right;
+  tree->token = *token;
+  tree->token.duplicated = 0;
+  tree->token.opt_subexp = 0;
+  tree->first = NULL;
+  tree->next = NULL;
+  tree->node_idx = REG_MISSING;
+
+  if (left != NULL)
+    left->parent = tree;
+  if (right != NULL)
+    right->parent = tree;
+  return tree;
+}
+
+/* Mark the tree SRC as an optional subexpression.
+   To be called from preorder or postorder.  */
+
+static reg_errcode_t
+mark_opt_subexp (void *extra, bin_tree_t *node)
+{
+  Idx idx = (Idx) (long) extra;
+  if (node->token.type == SUBEXP && node->token.opr.idx == idx)
+    node->token.opt_subexp = 1;
+
+  return REG_NOERROR;
+}
+
+/* Free the allocated memory inside NODE. */
+
+static void
+free_token (re_token_t *node)
+{
+#ifdef RE_ENABLE_I18N
+  if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
+    free_charset (node->opr.mbcset);
+  else
+#endif /* RE_ENABLE_I18N */
+    if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
+      re_free (node->opr.sbcset);
+}
+
+/* Worker function for tree walking.  Free the allocated memory inside NODE
+   and its children. */
+
+static reg_errcode_t
+free_tree (void *extra, bin_tree_t *node)
+{
+  free_token (&node->token);
+  return REG_NOERROR;
+}
+
+
+/* Duplicate the node SRC, and return new node.  This is a preorder
+   visit similar to the one implemented by the generic visitor, but
+   we need more infrastructure to maintain two parallel trees --- so,
+   it's easier to duplicate.  */
+
+static bin_tree_t *
+duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
+{
+  const bin_tree_t *node;
+  bin_tree_t *dup_root;
+  bin_tree_t **p_new = &dup_root, *dup_node = root->parent;
+
+  for (node = root; ; )
+    {
+      /* Create a new tree and link it back to the current parent.  */
+      *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
+      if (*p_new == NULL)
+       return NULL;
+      (*p_new)->parent = dup_node;
+      (*p_new)->token.duplicated = 1;
+      dup_node = *p_new;
+
+      /* Go to the left node, or up and to the right.  */
+      if (node->left)
+       {
+         node = node->left;
+         p_new = &dup_node->left;
+       }
+      else
+       {
+         const bin_tree_t *prev = NULL;
+         while (node->right == prev || node->right == NULL)
+           {
+             prev = node;
+             node = node->parent;
+             dup_node = dup_node->parent;
+             if (!node)
+               return dup_root;
+           }
+         node = node->right;
+         p_new = &dup_node->right;
+       }
+    }
+}
diff --git a/lib/regex.c b/lib/regex.c
new file mode 100644
index 0000000..6e0f752
--- /dev/null
+++ b/lib/regex.c
@@ -0,0 +1,72 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2003, 2005-2006, 2009-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <address@hidden>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include <config.h>
+
+/* Make sure noone compiles this code with a C++ compiler.  */
+#if defined __cplusplus && defined _LIBC
+# error "This is C code, use a C compiler"
+#endif
+
+#ifdef _LIBC
+/* We have to keep the namespace clean.  */
+# define regfree(preg) __regfree (preg)
+# define regexec(pr, st, nm, pm, ef) __regexec (pr, st, nm, pm, ef)
+# define regcomp(preg, pattern, cflags) __regcomp (preg, pattern, cflags)
+# define regerror(errcode, preg, errbuf, errbuf_size) \
+       __regerror(errcode, preg, errbuf, errbuf_size)
+# define re_set_registers(bu, re, nu, st, en) \
+       __re_set_registers (bu, re, nu, st, en)
+# define re_match_2(bufp, string1, size1, string2, size2, pos, regs, stop) \
+       __re_match_2 (bufp, string1, size1, string2, size2, pos, regs, stop)
+# define re_match(bufp, string, size, pos, regs) \
+       __re_match (bufp, string, size, pos, regs)
+# define re_search(bufp, string, size, startpos, range, regs) \
+       __re_search (bufp, string, size, startpos, range, regs)
+# define re_compile_pattern(pattern, length, bufp) \
+       __re_compile_pattern (pattern, length, bufp)
+# define re_set_syntax(syntax) __re_set_syntax (syntax)
+# define re_search_2(bufp, st1, s1, st2, s2, startpos, range, regs, stop) \
+       __re_search_2 (bufp, st1, s1, st2, s2, startpos, range, regs, stop)
+# define re_compile_fastmap(bufp) __re_compile_fastmap (bufp)
+
+# include "../locale/localeinfo.h"
+#endif
+
+/* On some systems, limits.h sets RE_DUP_MAX to a lower value than
+   GNU regex allows.  Include it before <regex.h>, which correctly
+   #undefs RE_DUP_MAX and sets it to the right value.  */
+#include <limits.h>
+#include <strings.h>
+
+#include <regex.h>
+#include "regex_internal.h"
+
+#include "regex_internal.c"
+#include "regcomp.c"
+#include "regexec.c"
+
+/* Binary backward compatibility.  */
+#if _LIBC
+# include <shlib-compat.h>
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3)
+link_warning (re_max_failures, "the 're_max_failures' variable is obsolete and 
will go away.")
+int re_max_failures = 2000;
+# endif
+#endif
diff --git a/lib/regex.h b/lib/regex.h
new file mode 100644
index 0000000..b612adb
--- /dev/null
+++ b/lib/regex.h
@@ -0,0 +1,675 @@
+/* Definitions for data structures and routines for the regular
+   expression library.
+   Copyright (C) 1985, 1989-1993, 1995-1998, 2000-2003, 2005-2006, 2009-2012
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifndef _REGEX_H
+#define _REGEX_H 1
+
+#include <sys/types.h>
+
+/* Allow the use in C++ code.  */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Define __USE_GNU_REGEX to declare GNU extensions that violate the
+   POSIX name space rules.  */
+#undef __USE_GNU_REGEX
+#if (defined _GNU_SOURCE                                       \
+     || (!defined _POSIX_C_SOURCE && !defined _POSIX_SOURCE    \
+        && !defined _XOPEN_SOURCE))
+# define __USE_GNU_REGEX 1
+#endif
+
+#ifdef _REGEX_LARGE_OFFSETS
+
+/* Use types and values that are wide enough to represent signed and
+   unsigned byte offsets in memory.  This currently works only when
+   the regex code is used outside of the GNU C library; it is not yet
+   supported within glibc itself, and glibc users should not define
+   _REGEX_LARGE_OFFSETS.  */
+
+/* The type of the offset of a byte within a string.
+   For historical reasons POSIX 1003.1-2004 requires that regoff_t be
+   at least as wide as off_t.  However, many common POSIX platforms set
+   regoff_t to the more-sensible ssize_t and the Open Group has
+   signalled its intention to change the requirement to be that
+   regoff_t be at least as wide as ptrdiff_t and ssize_t; see XBD ERN
+   60 (2005-08-25).  We don't know of any hosts where ssize_t or
+   ptrdiff_t is wider than ssize_t, so ssize_t is safe.  */
+typedef ssize_t regoff_t;
+
+/* The type of nonnegative object indexes.  Traditionally, GNU regex
+   uses 'int' for these.  Code that uses __re_idx_t should work
+   regardless of whether the type is signed.  */
+typedef size_t __re_idx_t;
+
+/* The type of object sizes.  */
+typedef size_t __re_size_t;
+
+/* The type of object sizes, in places where the traditional code
+   uses unsigned long int.  */
+typedef size_t __re_long_size_t;
+
+#else
+
+/* Use types that are binary-compatible with the traditional GNU regex
+   implementation, which mishandles strings longer than INT_MAX.  */
+
+typedef int regoff_t;
+typedef int __re_idx_t;
+typedef unsigned int __re_size_t;
+typedef unsigned long int __re_long_size_t;
+
+#endif
+
+/* The following two types have to be signed and unsigned integer type
+   wide enough to hold a value of a pointer.  For most ANSI compilers
+   ptrdiff_t and size_t should be likely OK.  Still size of these two
+   types is 2 for Microsoft C.  Ugh... */
+typedef long int s_reg_t;
+typedef unsigned long int active_reg_t;
+
+/* The following bits are used to determine the regexp syntax we
+   recognize.  The set/not-set meanings are chosen so that Emacs syntax
+   remains the value 0.  The bits are given in alphabetical order, and
+   the definitions shifted by one from the previous bit; thus, when we
+   add or remove a bit, only one other definition need change.  */
+typedef unsigned long int reg_syntax_t;
+
+#ifdef __USE_GNU_REGEX
+
+/* If this bit is not set, then \ inside a bracket expression is literal.
+   If set, then such a \ quotes the following character.  */
+# define RE_BACKSLASH_ESCAPE_IN_LISTS ((unsigned long int) 1)
+
+/* If this bit is not set, then + and ? are operators, and \+ and \? are
+     literals.
+   If set, then \+ and \? are operators and + and ? are literals.  */
+# define RE_BK_PLUS_QM (RE_BACKSLASH_ESCAPE_IN_LISTS << 1)
+
+/* If this bit is set, then character classes are supported.  They are:
+     [:alpha:], [:upper:], [:lower:],  [:digit:], [:alnum:], [:xdigit:],
+     [:space:], [:print:], [:punct:], [:graph:], and [:cntrl:].
+   If not set, then character classes are not supported.  */
+# define RE_CHAR_CLASSES (RE_BK_PLUS_QM << 1)
+
+/* If this bit is set, then ^ and $ are always anchors (outside bracket
+     expressions, of course).
+   If this bit is not set, then it depends:
+       ^  is an anchor if it is at the beginning of a regular
+          expression or after an open-group or an alternation operator;
+       $  is an anchor if it is at the end of a regular expression, or
+          before a close-group or an alternation operator.
+
+   This bit could be (re)combined with RE_CONTEXT_INDEP_OPS, because
+   POSIX draft 11.2 says that * etc. in leading positions is undefined.
+   We already implemented a previous draft which made those constructs
+   invalid, though, so we haven't changed the code back.  */
+# define RE_CONTEXT_INDEP_ANCHORS (RE_CHAR_CLASSES << 1)
+
+/* If this bit is set, then special characters are always special
+     regardless of where they are in the pattern.
+   If this bit is not set, then special characters are special only in
+     some contexts; otherwise they are ordinary.  Specifically,
+     * + ? and intervals are only special when not after the beginning,
+     open-group, or alternation operator.  */
+# define RE_CONTEXT_INDEP_OPS (RE_CONTEXT_INDEP_ANCHORS << 1)
+
+/* If this bit is set, then *, +, ?, and { cannot be first in an re or
+     immediately after an alternation or begin-group operator.  */
+# define RE_CONTEXT_INVALID_OPS (RE_CONTEXT_INDEP_OPS << 1)
+
+/* If this bit is set, then . matches newline.
+   If not set, then it doesn't.  */
+# define RE_DOT_NEWLINE (RE_CONTEXT_INVALID_OPS << 1)
+
+/* If this bit is set, then . doesn't match NUL.
+   If not set, then it does.  */
+# define RE_DOT_NOT_NULL (RE_DOT_NEWLINE << 1)
+
+/* If this bit is set, nonmatching lists [^...] do not match newline.
+   If not set, they do.  */
+# define RE_HAT_LISTS_NOT_NEWLINE (RE_DOT_NOT_NULL << 1)
+
+/* If this bit is set, either \{...\} or {...} defines an
+     interval, depending on RE_NO_BK_BRACES.
+   If not set, \{, \}, {, and } are literals.  */
+# define RE_INTERVALS (RE_HAT_LISTS_NOT_NEWLINE << 1)
+
+/* If this bit is set, +, ? and | aren't recognized as operators.
+   If not set, they are.  */
+# define RE_LIMITED_OPS (RE_INTERVALS << 1)
+
+/* If this bit is set, newline is an alternation operator.
+   If not set, newline is literal.  */
+# define RE_NEWLINE_ALT (RE_LIMITED_OPS << 1)
+
+/* If this bit is set, then '{...}' defines an interval, and \{ and \}
+     are literals.
+  If not set, then '\{...\}' defines an interval.  */
+# define RE_NO_BK_BRACES (RE_NEWLINE_ALT << 1)
+
+/* If this bit is set, (...) defines a group, and \( and \) are literals.
+   If not set, \(...\) defines a group, and ( and ) are literals.  */
+# define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
+
+/* If this bit is set, then \<digit> matches <digit>.
+   If not set, then \<digit> is a back-reference.  */
+# define RE_NO_BK_REFS (RE_NO_BK_PARENS << 1)
+
+/* If this bit is set, then | is an alternation operator, and \| is literal.
+   If not set, then \| is an alternation operator, and | is literal.  */
+# define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
+
+/* If this bit is set, then an ending range point collating higher
+     than the starting range point, as in [z-a], is invalid.
+   If not set, then when ending range point collates higher than the
+     starting range point, the range is ignored.  */
+# define RE_NO_EMPTY_RANGES (RE_NO_BK_VBAR << 1)
+
+/* If this bit is set, then an unmatched ) is ordinary.
+   If not set, then an unmatched ) is invalid.  */
+# define RE_UNMATCHED_RIGHT_PAREN_ORD (RE_NO_EMPTY_RANGES << 1)
+
+/* If this bit is set, succeed as soon as we match the whole pattern,
+   without further backtracking.  */
+# define RE_NO_POSIX_BACKTRACKING (RE_UNMATCHED_RIGHT_PAREN_ORD << 1)
+
+/* If this bit is set, do not process the GNU regex operators.
+   If not set, then the GNU regex operators are recognized. */
+# define RE_NO_GNU_OPS (RE_NO_POSIX_BACKTRACKING << 1)
+
+/* If this bit is set, turn on internal regex debugging.
+   If not set, and debugging was on, turn it off.
+   This only works if regex.c is compiled -DDEBUG.
+   We define this bit always, so that all that's needed to turn on
+   debugging is to recompile regex.c; the calling code can always have
+   this bit set, and it won't affect anything in the normal case. */
+# define RE_DEBUG (RE_NO_GNU_OPS << 1)
+
+/* If this bit is set, a syntactically invalid interval is treated as
+   a string of ordinary characters.  For example, the ERE 'a{1' is
+   treated as 'a\{1'.  */
+# define RE_INVALID_INTERVAL_ORD (RE_DEBUG << 1)
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+# define RE_ICASE (RE_INVALID_INTERVAL_ORD << 1)
+
+/* This bit is used internally like RE_CONTEXT_INDEP_ANCHORS but only
+   for ^, because it is difficult to scan the regex backwards to find
+   whether ^ should be special.  */
+# define RE_CARET_ANCHORS_HERE (RE_ICASE << 1)
+
+/* If this bit is set, then \{ cannot be first in a regex or
+   immediately after an alternation, open-group or \} operator.  */
+# define RE_CONTEXT_INVALID_DUP (RE_CARET_ANCHORS_HERE << 1)
+
+/* If this bit is set, then no_sub will be set to 1 during
+   re_compile_pattern.  */
+# define RE_NO_SUB (RE_CONTEXT_INVALID_DUP << 1)
+
+#endif /* defined __USE_GNU_REGEX */
+
+/* This global variable defines the particular regexp syntax to use (for
+   some interfaces).  When a regexp is compiled, the syntax used is
+   stored in the pattern buffer, so changing this does not affect
+   already-compiled regexps.  */
+extern reg_syntax_t re_syntax_options;
+
+#ifdef __USE_GNU_REGEX
+/* Define combinations of the above bits for the standard possibilities.
+   (The [[[ comments delimit what gets put into the Texinfo file, so
+   don't delete them!)  */
+/* [[[begin syntaxes]]] */
+# define RE_SYNTAX_EMACS 0
+
+# define RE_SYNTAX_AWK                                                 \
+  (RE_BACKSLASH_ESCAPE_IN_LISTS   | RE_DOT_NOT_NULL                    \
+   | RE_NO_BK_PARENS              | RE_NO_BK_REFS                      \
+   | RE_NO_BK_VBAR                | RE_NO_EMPTY_RANGES                 \
+   | RE_DOT_NEWLINE              | RE_CONTEXT_INDEP_ANCHORS            \
+   | RE_UNMATCHED_RIGHT_PAREN_ORD | RE_NO_GNU_OPS)
+
+# define RE_SYNTAX_GNU_AWK                                             \
+  ((RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DEBUG)        
\
+   & ~(RE_DOT_NOT_NULL | RE_INTERVALS | RE_CONTEXT_INDEP_OPS           \
+       | RE_CONTEXT_INVALID_OPS ))
+
+# define RE_SYNTAX_POSIX_AWK                                           \
+  (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS             \
+   | RE_INTERVALS          | RE_NO_GNU_OPS)
+
+# define RE_SYNTAX_GREP                                                        
\
+  (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                                
\
+   | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                           \
+   | RE_NEWLINE_ALT)
+
+# define RE_SYNTAX_EGREP                                               \
+  (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                   \
+   | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                   \
+   | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                            \
+   | RE_NO_BK_VBAR)
+
+# define RE_SYNTAX_POSIX_EGREP                                         \
+  (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES                    \
+   | RE_INVALID_INTERVAL_ORD)
+
+/* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
+# define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC
+
+# define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC
+
+/* Syntax bits common to both basic and extended POSIX regex syntax.  */
+# define _RE_SYNTAX_POSIX_COMMON                                       \
+  (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL             \
+   | RE_INTERVALS  | RE_NO_EMPTY_RANGES)
+
+# define RE_SYNTAX_POSIX_BASIC                                         \
+  (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM | RE_CONTEXT_INVALID_DUP)
+
+/* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
+   RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
+   isn't minimal, since other operators, such as \`, aren't disabled.  */
+# define RE_SYNTAX_POSIX_MINIMAL_BASIC                                 \
+  (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)
+
+# define RE_SYNTAX_POSIX_EXTENDED                                      \
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                 \
+   | RE_CONTEXT_INDEP_OPS   | RE_NO_BK_BRACES                          \
+   | RE_NO_BK_PARENS        | RE_NO_BK_VBAR                            \
+   | RE_CONTEXT_INVALID_OPS | RE_UNMATCHED_RIGHT_PAREN_ORD)
+
+/* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INDEP_OPS is
+   removed and RE_NO_BK_REFS is added.  */
+# define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                              \
+  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                 \
+   | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                          \
+   | RE_NO_BK_PARENS        | RE_NO_BK_REFS                            \
+   | RE_NO_BK_VBAR         | RE_UNMATCHED_RIGHT_PAREN_ORD)
+/* [[[end syntaxes]]] */
+
+#endif /* defined __USE_GNU_REGEX */
+
+#ifdef __USE_GNU_REGEX
+
+/* Maximum number of duplicates an interval can allow.  POSIX-conforming
+   systems might define this in <limits.h>, but we want our
+   value, so remove any previous define.  */
+# ifdef RE_DUP_MAX
+#  undef RE_DUP_MAX
+# endif
+
+/* RE_DUP_MAX is 2**15 - 1 because an earlier implementation stored
+   the counter as a 2-byte signed integer.  This is no longer true, so
+   RE_DUP_MAX could be increased to (INT_MAX / 10 - 1), or to
+   ((SIZE_MAX - 2) / 10 - 1) if _REGEX_LARGE_OFFSETS is defined.
+   However, there would be a huge performance problem if someone
+   actually used a pattern like a\{214748363\}, so RE_DUP_MAX retains
+   its historical value.  */
+# define RE_DUP_MAX (0x7fff)
+
+#endif /* defined __USE_GNU_REGEX */
+
+
+/* POSIX 'cflags' bits (i.e., information for 'regcomp').  */
+
+/* If this bit is set, then use extended regular expression syntax.
+   If not set, then use basic regular expression syntax.  */
+#define REG_EXTENDED 1
+
+/* If this bit is set, then ignore case when matching.
+   If not set, then case is significant.  */
+#define REG_ICASE (1 << 1)
+
+/* If this bit is set, then anchors do not match at newline
+     characters in the string.
+   If not set, then anchors do match at newlines.  */
+#define REG_NEWLINE (1 << 2)
+
+/* If this bit is set, then report only success or fail in regexec.
+   If not set, then returns differ between not matching and errors.  */
+#define REG_NOSUB (1 << 3)
+
+
+/* POSIX 'eflags' bits (i.e., information for regexec).  */
+
+/* If this bit is set, then the beginning-of-line operator doesn't match
+     the beginning of the string (presumably because it's not the
+     beginning of a line).
+   If not set, then the beginning-of-line operator does match the
+     beginning of the string.  */
+#define REG_NOTBOL 1
+
+/* Like REG_NOTBOL, except for the end-of-line.  */
+#define REG_NOTEOL (1 << 1)
+
+/* Use PMATCH[0] to delimit the start and end of the search in the
+   buffer.  */
+#define REG_STARTEND (1 << 2)
+
+
+/* If any error codes are removed, changed, or added, update the
+   '__re_error_msgid' table in regcomp.c.  */
+
+typedef enum
+{
+  _REG_ENOSYS = -1,    /* This will never happen for this implementation.  */
+  _REG_NOERROR = 0,    /* Success.  */
+  _REG_NOMATCH,                /* Didn't find a match (for regexec).  */
+
+  /* POSIX regcomp return error codes.  (In the order listed in the
+     standard.)  */
+  _REG_BADPAT,         /* Invalid pattern.  */
+  _REG_ECOLLATE,       /* Invalid collating element.  */
+  _REG_ECTYPE,         /* Invalid character class name.  */
+  _REG_EESCAPE,                /* Trailing backslash.  */
+  _REG_ESUBREG,                /* Invalid back reference.  */
+  _REG_EBRACK,         /* Unmatched left bracket.  */
+  _REG_EPAREN,         /* Parenthesis imbalance.  */
+  _REG_EBRACE,         /* Unmatched \{.  */
+  _REG_BADBR,          /* Invalid contents of \{\}.  */
+  _REG_ERANGE,         /* Invalid range end.  */
+  _REG_ESPACE,         /* Ran out of memory.  */
+  _REG_BADRPT,         /* No preceding re for repetition op.  */
+
+  /* Error codes we've added.  */
+  _REG_EEND,           /* Premature end.  */
+  _REG_ESIZE,          /* Compiled pattern bigger than 2^16 bytes.  */
+  _REG_ERPAREN         /* Unmatched ) or \); not returned from regcomp.  */
+} reg_errcode_t;
+
+#ifdef _XOPEN_SOURCE
+# define REG_ENOSYS    _REG_ENOSYS
+#endif
+#define REG_NOERROR    _REG_NOERROR
+#define REG_NOMATCH    _REG_NOMATCH
+#define REG_BADPAT     _REG_BADPAT
+#define REG_ECOLLATE   _REG_ECOLLATE
+#define REG_ECTYPE     _REG_ECTYPE
+#define REG_EESCAPE    _REG_EESCAPE
+#define REG_ESUBREG    _REG_ESUBREG
+#define REG_EBRACK     _REG_EBRACK
+#define REG_EPAREN     _REG_EPAREN
+#define REG_EBRACE     _REG_EBRACE
+#define REG_BADBR      _REG_BADBR
+#define REG_ERANGE     _REG_ERANGE
+#define REG_ESPACE     _REG_ESPACE
+#define REG_BADRPT     _REG_BADRPT
+#define REG_EEND       _REG_EEND
+#define REG_ESIZE      _REG_ESIZE
+#define REG_ERPAREN    _REG_ERPAREN
+
+/* struct re_pattern_buffer normally uses member names like 'buffer'
+   that POSIX does not allow.  In POSIX mode these members have names
+   with leading 're_' (e.g., 're_buffer').  */
+#ifdef __USE_GNU_REGEX
+# define _REG_RE_NAME(id) id
+# define _REG_RM_NAME(id) id
+#else
+# define _REG_RE_NAME(id) re_##id
+# define _REG_RM_NAME(id) rm_##id
+#endif
+
+/* The user can specify the type of the re_translate member by
+   defining the macro RE_TRANSLATE_TYPE, which defaults to unsigned
+   char *.  This pollutes the POSIX name space, so in POSIX mode just
+   use unsigned char *.  */
+#ifdef __USE_GNU_REGEX
+# ifndef RE_TRANSLATE_TYPE
+#  define RE_TRANSLATE_TYPE unsigned char *
+# endif
+# define REG_TRANSLATE_TYPE RE_TRANSLATE_TYPE
+#else
+# define REG_TRANSLATE_TYPE unsigned char *
+#endif
+
+/* This data structure represents a compiled pattern.  Before calling
+   the pattern compiler, the fields 'buffer', 'allocated', 'fastmap',
+   'translate', and 'no_sub' can be set.  After the pattern has been
+   compiled, the 're_nsub' field is available.  All other fields are
+   private to the regex routines.  */
+
+struct re_pattern_buffer
+{
+  /* Space that holds the compiled pattern.  It is declared as
+     'unsigned char *' because its elements are sometimes used as
+     array indexes.  */
+  unsigned char *_REG_RE_NAME (buffer);
+
+  /* Number of bytes to which 'buffer' points.  */
+  __re_long_size_t _REG_RE_NAME (allocated);
+
+  /* Number of bytes actually used in 'buffer'.  */
+  __re_long_size_t _REG_RE_NAME (used);
+
+  /* Syntax setting with which the pattern was compiled.  */
+  reg_syntax_t _REG_RE_NAME (syntax);
+
+  /* Pointer to a fastmap, if any, otherwise zero.  re_search uses the
+     fastmap, if there is one, to skip over impossible starting points
+     for matches.  */
+  char *_REG_RE_NAME (fastmap);
+
+  /* Either a translate table to apply to all characters before
+     comparing them, or zero for no translation.  The translation is
+     applied to a pattern when it is compiled and to a string when it
+     is matched.  */
+  REG_TRANSLATE_TYPE _REG_RE_NAME (translate);
+
+  /* Number of subexpressions found by the compiler.  */
+  size_t re_nsub;
+
+  /* Zero if this pattern cannot match the empty string, one else.
+     Well, in truth it's used only in 're_search_2', to see whether or
+     not we should use the fastmap, so we don't set this absolutely
+     perfectly; see 're_compile_fastmap' (the "duplicate" case).  */
+  unsigned int _REG_RE_NAME (can_be_null) : 1;
+
+  /* If REGS_UNALLOCATED, allocate space in the 'regs' structure
+     for 'max (RE_NREGS, re_nsub + 1)' groups.
+     If REGS_REALLOCATE, reallocate space if necessary.
+     If REGS_FIXED, use what's there.  */
+#ifdef __USE_GNU_REGEX
+# define REGS_UNALLOCATED 0
+# define REGS_REALLOCATE 1
+# define REGS_FIXED 2
+#endif
+  unsigned int _REG_RE_NAME (regs_allocated) : 2;
+
+  /* Set to zero when 're_compile_pattern' compiles a pattern; set to
+     one by 're_compile_fastmap' if it updates the fastmap.  */
+  unsigned int _REG_RE_NAME (fastmap_accurate) : 1;
+
+  /* If set, 're_match_2' does not return information about
+     subexpressions.  */
+  unsigned int _REG_RE_NAME (no_sub) : 1;
+
+  /* If set, a beginning-of-line anchor doesn't match at the beginning
+     of the string.  */
+  unsigned int _REG_RE_NAME (not_bol) : 1;
+
+  /* Similarly for an end-of-line anchor.  */
+  unsigned int _REG_RE_NAME (not_eol) : 1;
+
+  /* If true, an anchor at a newline matches.  */
+  unsigned int _REG_RE_NAME (newline_anchor) : 1;
+
+/* [[[end pattern_buffer]]] */
+};
+
+typedef struct re_pattern_buffer regex_t;
+
+/* This is the structure we store register match data in.  See
+   regex.texinfo for a full description of what registers match.  */
+struct re_registers
+{
+  __re_size_t _REG_RM_NAME (num_regs);
+  regoff_t *_REG_RM_NAME (start);
+  regoff_t *_REG_RM_NAME (end);
+};
+
+
+/* If 'regs_allocated' is REGS_UNALLOCATED in the pattern buffer,
+   're_match_2' returns information about at least this many registers
+   the first time a 'regs' structure is passed.  */
+#if !defined RE_NREGS && defined __USE_GNU_REGEX
+# define RE_NREGS 30
+#endif
+
+
+/* POSIX specification for registers.  Aside from the different names than
+   're_registers', POSIX uses an array of structures, instead of a
+   structure of arrays.  */
+typedef struct
+{
+  regoff_t rm_so;  /* Byte offset from string's start to substring's start.  */
+  regoff_t rm_eo;  /* Byte offset from string's start to substring's end.  */
+} regmatch_t;
+
+/* Declarations for routines.  */
+
+/* Sets the current default syntax to SYNTAX, and return the old syntax.
+   You can also simply assign to the 're_syntax_options' variable.  */
+extern reg_syntax_t re_set_syntax (reg_syntax_t __syntax);
+
+/* Compile the regular expression PATTERN, with length LENGTH
+   and syntax given by the global 're_syntax_options', into the buffer
+   BUFFER.  Return NULL if successful, and an error string if not.  */
+extern const char *re_compile_pattern (const char *__pattern, size_t __length,
+                                      struct re_pattern_buffer *__buffer);
+
+
+/* Compile a fastmap for the compiled pattern in BUFFER; used to
+   accelerate searches.  Return 0 if successful and -2 if was an
+   internal error.  */
+extern int re_compile_fastmap (struct re_pattern_buffer *__buffer);
+
+
+/* Search in the string STRING (with length LENGTH) for the pattern
+   compiled into BUFFER.  Start searching at position START, for RANGE
+   characters.  Return the starting position of the match, -1 for no
+   match, or -2 for an internal error.  Also return register
+   information in REGS (if REGS and BUFFER->no_sub are nonzero).  */
+extern regoff_t re_search (struct re_pattern_buffer *__buffer,
+                          const char *__string, __re_idx_t __length,
+                          __re_idx_t __start, regoff_t __range,
+                          struct re_registers *__regs);
+
+
+/* Like 're_search', but search in the concatenation of STRING1 and
+   STRING2.  Also, stop searching at index START + STOP.  */
+extern regoff_t re_search_2 (struct re_pattern_buffer *__buffer,
+                            const char *__string1, __re_idx_t __length1,
+                            const char *__string2, __re_idx_t __length2,
+                            __re_idx_t __start, regoff_t __range,
+                            struct re_registers *__regs,
+                            __re_idx_t __stop);
+
+
+/* Like 're_search', but return how many characters in STRING the regexp
+   in BUFFER matched, starting at position START.  */
+extern regoff_t re_match (struct re_pattern_buffer *__buffer,
+                         const char *__string, __re_idx_t __length,
+                         __re_idx_t __start, struct re_registers *__regs);
+
+
+/* Relates to 're_match' as 're_search_2' relates to 're_search'.  */
+extern regoff_t re_match_2 (struct re_pattern_buffer *__buffer,
+                           const char *__string1, __re_idx_t __length1,
+                           const char *__string2, __re_idx_t __length2,
+                           __re_idx_t __start, struct re_registers *__regs,
+                           __re_idx_t __stop);
+
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using BUFFER and REGS will use this memory
+   for recording register information.  STARTS and ENDS must be
+   allocated with malloc, and must each be at least 'NUM_REGS * sizeof
+   (regoff_t)' bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   BUFFER will allocate its own register data, without freeing the old
+   data.  */
+extern void re_set_registers (struct re_pattern_buffer *__buffer,
+                             struct re_registers *__regs,
+                             __re_size_t __num_regs,
+                             regoff_t *__starts, regoff_t *__ends);
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+# ifndef _CRAY
+/* 4.2 bsd compatibility.  */
+extern char *re_comp (const char *);
+extern int re_exec (const char *);
+# endif
+#endif
+
+/* GCC 2.95 and later have "__restrict"; C99 compilers have
+   "restrict", and "configure" may have defined "restrict".
+   Other compilers use __restrict, __restrict__, and _Restrict, and
+   'configure' might #define 'restrict' to those words, so pick a
+   different name.  */
+#ifndef _Restrict_
+# if 199901L <= __STDC_VERSION__
+#  define _Restrict_ restrict
+# elif 2 < __GNUC__ || (2 == __GNUC__ && 95 <= __GNUC_MINOR__)
+#  define _Restrict_ __restrict
+# else
+#  define _Restrict_
+# endif
+#endif
+/* gcc 3.1 and up support the [restrict] syntax.  Don't trust
+   sys/cdefs.h's definition of __restrict_arr, though, as it
+   mishandles gcc -ansi -pedantic.  */
+#ifndef _Restrict_arr_
+# if ((199901L <= __STDC_VERSION__                                     \
+       || ((3 < __GNUC__ || (3 == __GNUC__ && 1 <= __GNUC_MINOR__))    \
+          && !defined __STRICT_ANSI__))                                        
\
+      && !defined __GNUG__)
+#  define _Restrict_arr_ _Restrict_
+# else
+#  define _Restrict_arr_
+# endif
+#endif
+
+/* POSIX compatibility.  */
+extern int regcomp (regex_t *_Restrict_ __preg,
+                   const char *_Restrict_ __pattern,
+                   int __cflags);
+
+extern int regexec (const regex_t *_Restrict_ __preg,
+                   const char *_Restrict_ __string, size_t __nmatch,
+                   regmatch_t __pmatch[_Restrict_arr_],
+                   int __eflags);
+
+extern size_t regerror (int __errcode, const regex_t *_Restrict_ __preg,
+                       char *_Restrict_ __errbuf, size_t __errbuf_size);
+
+extern void regfree (regex_t *__preg);
+
+
+#ifdef __cplusplus
+}
+#endif /* C++ */
+
+#endif /* regex.h */
diff --git a/lib/regex_internal.c b/lib/regex_internal.c
new file mode 100644
index 0000000..c029c23
--- /dev/null
+++ b/lib/regex_internal.c
@@ -0,0 +1,1741 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <address@hidden>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static void re_string_construct_common (const char *str, Idx len,
+                                       re_string_t *pstr,
+                                       RE_TRANSLATE_TYPE trans, bool icase,
+                                       const re_dfa_t *dfa) internal_function;
+static re_dfastate_t *create_ci_newstate (const re_dfa_t *dfa,
+                                         const re_node_set *nodes,
+                                         re_hashval_t hash) internal_function;
+static re_dfastate_t *create_cd_newstate (const re_dfa_t *dfa,
+                                         const re_node_set *nodes,
+                                         unsigned int context,
+                                         re_hashval_t hash) internal_function;
+
+/* Functions for string operation.  */
+
+/* This function allocate the buffers.  It is necessary to call
+   re_string_reconstruct before using the object.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_string_allocate (re_string_t *pstr, const char *str, Idx len, Idx init_len,
+                   RE_TRANSLATE_TYPE trans, bool icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  Idx init_buf_len;
+
+  /* Ensure at least one character fits into the buffers.  */
+  if (init_len < dfa->mb_cur_max)
+    init_len = dfa->mb_cur_max;
+  init_buf_len = (len + 1 < init_len) ? len + 1: init_len;
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  ret = re_string_realloc_buffers (pstr, init_buf_len);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  pstr->word_char = dfa->word_char;
+  pstr->word_ops_used = dfa->word_ops_used;
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+  pstr->valid_len = (pstr->mbs_allocated || dfa->mb_cur_max > 1) ? 0 : len;
+  pstr->valid_raw_len = pstr->valid_len;
+  return REG_NOERROR;
+}
+
+/* This function allocate the buffers, and initialize them.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_string_construct (re_string_t *pstr, const char *str, Idx len,
+                    RE_TRANSLATE_TYPE trans, bool icase, const re_dfa_t *dfa)
+{
+  reg_errcode_t ret;
+  memset (pstr, '\0', sizeof (re_string_t));
+  re_string_construct_common (str, len, pstr, trans, icase, dfa);
+
+  if (len > 0)
+    {
+      ret = re_string_realloc_buffers (pstr, len + 1);
+      if (BE (ret != REG_NOERROR, 0))
+       return ret;
+    }
+  pstr->mbs = pstr->mbs_allocated ? pstr->mbs : (unsigned char *) str;
+
+  if (icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+       {
+         while (1)
+           {
+             ret = build_wcs_upper_buffer (pstr);
+             if (BE (ret != REG_NOERROR, 0))
+               return ret;
+             if (pstr->valid_raw_len >= len)
+               break;
+             if (pstr->bufs_len > pstr->valid_len + dfa->mb_cur_max)
+               break;
+             ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+             if (BE (ret != REG_NOERROR, 0))
+               return ret;
+           }
+       }
+      else
+#endif /* RE_ENABLE_I18N  */
+       build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (dfa->mb_cur_max > 1)
+       build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+       {
+         if (trans != NULL)
+           re_string_translate_buffer (pstr);
+         else
+           {
+             pstr->valid_len = pstr->bufs_len;
+             pstr->valid_raw_len = pstr->bufs_len;
+           }
+       }
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions for re_string_allocate, and re_string_construct.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_string_realloc_buffers (re_string_t *pstr, Idx new_buf_len)
+{
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      wint_t *new_wcs;
+
+      /* Avoid overflow.  */
+      size_t max_object_size = MAX (sizeof (wint_t), sizeof (Idx));
+      if (BE (SIZE_MAX / max_object_size < new_buf_len, 0))
+       return REG_ESPACE;
+
+      new_wcs = re_realloc (pstr->wcs, wint_t, new_buf_len);
+      if (BE (new_wcs == NULL, 0))
+       return REG_ESPACE;
+      pstr->wcs = new_wcs;
+      if (pstr->offsets != NULL)
+       {
+         Idx *new_offsets = re_realloc (pstr->offsets, Idx, new_buf_len);
+         if (BE (new_offsets == NULL, 0))
+           return REG_ESPACE;
+         pstr->offsets = new_offsets;
+       }
+    }
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    {
+      unsigned char *new_mbs = re_realloc (pstr->mbs, unsigned char,
+                                          new_buf_len);
+      if (BE (new_mbs == NULL, 0))
+       return REG_ESPACE;
+      pstr->mbs = new_mbs;
+    }
+  pstr->bufs_len = new_buf_len;
+  return REG_NOERROR;
+}
+
+
+static void
+internal_function
+re_string_construct_common (const char *str, Idx len, re_string_t *pstr,
+                           RE_TRANSLATE_TYPE trans, bool icase,
+                           const re_dfa_t *dfa)
+{
+  pstr->raw_mbs = (const unsigned char *) str;
+  pstr->len = len;
+  pstr->raw_len = len;
+  pstr->trans = trans;
+  pstr->icase = icase;
+  pstr->mbs_allocated = (trans != NULL || icase);
+  pstr->mb_cur_max = dfa->mb_cur_max;
+  pstr->is_utf8 = dfa->is_utf8;
+  pstr->map_notascii = dfa->map_notascii;
+  pstr->stop = pstr->len;
+  pstr->raw_stop = pstr->stop;
+}
+
+#ifdef RE_ENABLE_I18N
+
+/* Build wide character buffer PSTR->WCS.
+   If the byte sequence of the string are:
+     <mb1>(0), <mb1>(1), <mb2>(0), <mb2>(1), <sb3>
+   Then wide character buffer will be:
+     <wc1>   , WEOF    , <wc2>   , WEOF    , <wc3>
+   We use WEOF for padding, they indicate that the position isn't
+   a first byte of a multibyte character.
+
+   Note that this function assumes PSTR->VALID_LEN elements are already
+   built and starts from PSTR->VALID_LEN.  */
+
+static void
+internal_function
+build_wcs_buffer (re_string_t *pstr)
+{
+#ifdef _LIBC
+  unsigned char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  unsigned char buf[64];
+#endif
+  mbstate_t prev_st;
+  Idx byte_idx, end_idx, remain_len;
+  size_t mbclen;
+
+  /* Build the buffers from pstr->valid_len to either pstr->len or
+     pstr->bufs_len.  */
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+  for (byte_idx = pstr->valid_len; byte_idx < end_idx;)
+    {
+      wchar_t wc;
+      const char *p;
+
+      remain_len = end_idx - byte_idx;
+      prev_st = pstr->cur_state;
+      /* Apply the translation if we need.  */
+      if (BE (pstr->trans != NULL, 0))
+       {
+         int i, ch;
+
+         for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+           {
+             ch = pstr->raw_mbs [pstr->raw_mbs_idx + byte_idx + i];
+             buf[i] = pstr->mbs[byte_idx + i] = pstr->trans[ch];
+           }
+         p = (const char *) buf;
+       }
+      else
+       p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx;
+      mbclen = __mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2, 0))
+       {
+         /* The buffer doesn't have enough space, finish to build.  */
+         pstr->cur_state = prev_st;
+         break;
+       }
+      else if (BE (mbclen == (size_t) -1 || mbclen == 0, 0))
+       {
+         /* We treat these cases as a singlebyte character.  */
+         mbclen = 1;
+         wc = (wchar_t) pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+         if (BE (pstr->trans != NULL, 0))
+           wc = pstr->trans[wc];
+         pstr->cur_state = prev_st;
+       }
+
+      /* Write wide character and padding.  */
+      pstr->wcs[byte_idx++] = wc;
+      /* Write paddings.  */
+      for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+       pstr->wcs[byte_idx++] = WEOF;
+    }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = byte_idx;
+}
+
+/* Build wide character buffer PSTR->WCS like build_wcs_buffer,
+   but for REG_ICASE.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+build_wcs_upper_buffer (re_string_t *pstr)
+{
+  mbstate_t prev_st;
+  Idx src_idx, byte_idx, end_idx, remain_len;
+  size_t mbclen;
+#ifdef _LIBC
+  char buf[MB_LEN_MAX];
+  assert (MB_LEN_MAX >= pstr->mb_cur_max);
+#else
+  char buf[64];
+#endif
+
+  byte_idx = pstr->valid_len;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  /* The following optimization assumes that ASCII characters can be
+     mapped to wide characters with a simple cast.  */
+  if (! pstr->map_notascii && pstr->trans == NULL && !pstr->offsets_needed)
+    {
+      while (byte_idx < end_idx)
+       {
+         wchar_t wc;
+
+         if (isascii (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx])
+             && mbsinit (&pstr->cur_state))
+           {
+             /* In case of a singlebyte character.  */
+             pstr->mbs[byte_idx]
+               = toupper (pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx]);
+             /* The next step uses the assumption that wchar_t is encoded
+                ASCII-safe: all ASCII values can be converted like this.  */
+             pstr->wcs[byte_idx] = (wchar_t) pstr->mbs[byte_idx];
+             ++byte_idx;
+             continue;
+           }
+
+         remain_len = end_idx - byte_idx;
+         prev_st = pstr->cur_state;
+         mbclen = __mbrtowc (&wc,
+                             ((const char *) pstr->raw_mbs + pstr->raw_mbs_idx
+                              + byte_idx), remain_len, &pstr->cur_state);
+         if (BE (mbclen < (size_t) -2, 1))
+           {
+             wchar_t wcu = wc;
+             if (iswlower (wc))
+               {
+                 size_t mbcdlen;
+
+                 wcu = towupper (wc);
+                 mbcdlen = wcrtomb (buf, wcu, &prev_st);
+                 if (BE (mbclen == mbcdlen, 1))
+                   memcpy (pstr->mbs + byte_idx, buf, mbclen);
+                 else
+                   {
+                     src_idx = byte_idx;
+                     goto offsets_needed;
+                   }
+               }
+             else
+               memcpy (pstr->mbs + byte_idx,
+                       pstr->raw_mbs + pstr->raw_mbs_idx + byte_idx, mbclen);
+             pstr->wcs[byte_idx++] = wcu;
+             /* Write paddings.  */
+             for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+               pstr->wcs[byte_idx++] = WEOF;
+           }
+         else if (mbclen == (size_t) -1 || mbclen == 0)
+           {
+             /* It is an invalid character or '\0'.  Just use the byte.  */
+             int ch = pstr->raw_mbs[pstr->raw_mbs_idx + byte_idx];
+             pstr->mbs[byte_idx] = ch;
+             /* And also cast it to wide char.  */
+             pstr->wcs[byte_idx++] = (wchar_t) ch;
+             if (BE (mbclen == (size_t) -1, 0))
+               pstr->cur_state = prev_st;
+           }
+         else
+           {
+             /* The buffer doesn't have enough space, finish to build.  */
+             pstr->cur_state = prev_st;
+             break;
+           }
+       }
+      pstr->valid_len = byte_idx;
+      pstr->valid_raw_len = byte_idx;
+      return REG_NOERROR;
+    }
+  else
+    for (src_idx = pstr->valid_raw_len; byte_idx < end_idx;)
+      {
+       wchar_t wc;
+       const char *p;
+      offsets_needed:
+       remain_len = end_idx - byte_idx;
+       prev_st = pstr->cur_state;
+       if (BE (pstr->trans != NULL, 0))
+         {
+           int i, ch;
+
+           for (i = 0; i < pstr->mb_cur_max && i < remain_len; ++i)
+             {
+               ch = pstr->raw_mbs [pstr->raw_mbs_idx + src_idx + i];
+               buf[i] = pstr->trans[ch];
+             }
+           p = (const char *) buf;
+         }
+       else
+         p = (const char *) pstr->raw_mbs + pstr->raw_mbs_idx + src_idx;
+       mbclen = __mbrtowc (&wc, p, remain_len, &pstr->cur_state);
+       if (BE (mbclen < (size_t) -2, 1))
+         {
+           wchar_t wcu = wc;
+           if (iswlower (wc))
+             {
+               size_t mbcdlen;
+
+               wcu = towupper (wc);
+               mbcdlen = wcrtomb ((char *) buf, wcu, &prev_st);
+               if (BE (mbclen == mbcdlen, 1))
+                 memcpy (pstr->mbs + byte_idx, buf, mbclen);
+               else if (mbcdlen != (size_t) -1)
+                 {
+                   size_t i;
+
+                   if (byte_idx + mbcdlen > pstr->bufs_len)
+                     {
+                       pstr->cur_state = prev_st;
+                       break;
+                     }
+
+                   if (pstr->offsets == NULL)
+                     {
+                       pstr->offsets = re_malloc (Idx, pstr->bufs_len);
+
+                       if (pstr->offsets == NULL)
+                         return REG_ESPACE;
+                     }
+                   if (!pstr->offsets_needed)
+                     {
+                       for (i = 0; i < (size_t) byte_idx; ++i)
+                         pstr->offsets[i] = i;
+                       pstr->offsets_needed = 1;
+                     }
+
+                   memcpy (pstr->mbs + byte_idx, buf, mbcdlen);
+                   pstr->wcs[byte_idx] = wcu;
+                   pstr->offsets[byte_idx] = src_idx;
+                   for (i = 1; i < mbcdlen; ++i)
+                     {
+                       pstr->offsets[byte_idx + i]
+                         = src_idx + (i < mbclen ? i : mbclen - 1);
+                       pstr->wcs[byte_idx + i] = WEOF;
+                     }
+                   pstr->len += mbcdlen - mbclen;
+                   if (pstr->raw_stop > src_idx)
+                     pstr->stop += mbcdlen - mbclen;
+                   end_idx = (pstr->bufs_len > pstr->len)
+                             ? pstr->len : pstr->bufs_len;
+                   byte_idx += mbcdlen;
+                   src_idx += mbclen;
+                   continue;
+                 }
+               else
+                 memcpy (pstr->mbs + byte_idx, p, mbclen);
+             }
+           else
+             memcpy (pstr->mbs + byte_idx, p, mbclen);
+
+           if (BE (pstr->offsets_needed != 0, 0))
+             {
+               size_t i;
+               for (i = 0; i < mbclen; ++i)
+                 pstr->offsets[byte_idx + i] = src_idx + i;
+             }
+           src_idx += mbclen;
+
+           pstr->wcs[byte_idx++] = wcu;
+           /* Write paddings.  */
+           for (remain_len = byte_idx + mbclen - 1; byte_idx < remain_len ;)
+             pstr->wcs[byte_idx++] = WEOF;
+         }
+       else if (mbclen == (size_t) -1 || mbclen == 0)
+         {
+           /* It is an invalid character or '\0'.  Just use the byte.  */
+           int ch = pstr->raw_mbs[pstr->raw_mbs_idx + src_idx];
+
+           if (BE (pstr->trans != NULL, 0))
+             ch = pstr->trans [ch];
+           pstr->mbs[byte_idx] = ch;
+
+           if (BE (pstr->offsets_needed != 0, 0))
+             pstr->offsets[byte_idx] = src_idx;
+           ++src_idx;
+
+           /* And also cast it to wide char.  */
+           pstr->wcs[byte_idx++] = (wchar_t) ch;
+           if (BE (mbclen == (size_t) -1, 0))
+             pstr->cur_state = prev_st;
+         }
+       else
+         {
+           /* The buffer doesn't have enough space, finish to build.  */
+           pstr->cur_state = prev_st;
+           break;
+         }
+      }
+  pstr->valid_len = byte_idx;
+  pstr->valid_raw_len = src_idx;
+  return REG_NOERROR;
+}
+
+/* Skip characters until the index becomes greater than NEW_RAW_IDX.
+   Return the index.  */
+
+static Idx
+internal_function
+re_string_skip_chars (re_string_t *pstr, Idx new_raw_idx, wint_t *last_wc)
+{
+  mbstate_t prev_st;
+  Idx rawbuf_idx;
+  size_t mbclen;
+  wint_t wc = WEOF;
+
+  /* Skip the characters which are not necessary to check.  */
+  for (rawbuf_idx = pstr->raw_mbs_idx + pstr->valid_raw_len;
+       rawbuf_idx < new_raw_idx;)
+    {
+      wchar_t wc2;
+      Idx remain_len;
+      remain_len = pstr->len - rawbuf_idx;
+      prev_st = pstr->cur_state;
+      mbclen = __mbrtowc (&wc2, (const char *) pstr->raw_mbs + rawbuf_idx,
+                         remain_len, &pstr->cur_state);
+      if (BE (mbclen == (size_t) -2 || mbclen == (size_t) -1 || mbclen == 0, 
0))
+       {
+         /* We treat these cases as a single byte character.  */
+         if (mbclen == 0 || remain_len == 0)
+           wc = L'\0';
+         else
+           wc = *(unsigned char *) (pstr->raw_mbs + rawbuf_idx);
+         mbclen = 1;
+         pstr->cur_state = prev_st;
+       }
+      else
+       wc = wc2;
+      /* Then proceed the next character.  */
+      rawbuf_idx += mbclen;
+    }
+  *last_wc = wc;
+  return rawbuf_idx;
+}
+#endif /* RE_ENABLE_I18N  */
+
+/* Build the buffer PSTR->MBS, and apply the translation if we need.
+   This function is used in case of REG_ICASE.  */
+
+static void
+internal_function
+build_upper_buffer (re_string_t *pstr)
+{
+  Idx char_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (char_idx = pstr->valid_len; char_idx < end_idx; ++char_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + char_idx];
+      if (BE (pstr->trans != NULL, 0))
+       ch = pstr->trans[ch];
+      if (islower (ch))
+       pstr->mbs[char_idx] = toupper (ch);
+      else
+       pstr->mbs[char_idx] = ch;
+    }
+  pstr->valid_len = char_idx;
+  pstr->valid_raw_len = char_idx;
+}
+
+/* Apply TRANS to the buffer in PSTR.  */
+
+static void
+internal_function
+re_string_translate_buffer (re_string_t *pstr)
+{
+  Idx buf_idx, end_idx;
+  end_idx = (pstr->bufs_len > pstr->len) ? pstr->len : pstr->bufs_len;
+
+  for (buf_idx = pstr->valid_len; buf_idx < end_idx; ++buf_idx)
+    {
+      int ch = pstr->raw_mbs[pstr->raw_mbs_idx + buf_idx];
+      pstr->mbs[buf_idx] = pstr->trans[ch];
+    }
+
+  pstr->valid_len = buf_idx;
+  pstr->valid_raw_len = buf_idx;
+}
+
+/* This function re-construct the buffers.
+   Concretely, convert to wide character in case of pstr->mb_cur_max > 1,
+   convert to upper case in case of REG_ICASE, apply translation.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_string_reconstruct (re_string_t *pstr, Idx idx, int eflags)
+{
+  Idx offset;
+
+  if (BE (pstr->raw_mbs_idx <= idx, 0))
+    offset = idx - pstr->raw_mbs_idx;
+  else
+    {
+      /* Reset buffer.  */
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+       memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+#endif /* RE_ENABLE_I18N */
+      pstr->len = pstr->raw_len;
+      pstr->stop = pstr->raw_stop;
+      pstr->valid_len = 0;
+      pstr->raw_mbs_idx = 0;
+      pstr->valid_raw_len = 0;
+      pstr->offsets_needed = 0;
+      pstr->tip_context = ((eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+                          : CONTEXT_NEWLINE | CONTEXT_BEGBUF);
+      if (!pstr->mbs_allocated)
+       pstr->mbs = (unsigned char *) pstr->raw_mbs;
+      offset = idx;
+    }
+
+  if (BE (offset != 0, 1))
+    {
+      /* Should the already checked characters be kept?  */
+      if (BE (offset < pstr->valid_raw_len, 1))
+       {
+         /* Yes, move them to the front of the buffer.  */
+#ifdef RE_ENABLE_I18N
+         if (BE (pstr->offsets_needed, 0))
+           {
+             Idx low = 0, high = pstr->valid_len, mid;
+             do
+               {
+                 mid = (high + low) / 2;
+                 if (pstr->offsets[mid] > offset)
+                   high = mid;
+                 else if (pstr->offsets[mid] < offset)
+                   low = mid + 1;
+                 else
+                   break;
+               }
+             while (low < high);
+             if (pstr->offsets[mid] < offset)
+               ++mid;
+             pstr->tip_context = re_string_context_at (pstr, mid - 1,
+                                                       eflags);
+             /* This can be quite complicated, so handle specially
+                only the common and easy case where the character with
+                different length representation of lower and upper
+                case is present at or after offset.  */
+             if (pstr->valid_len > offset
+                 && mid == offset && pstr->offsets[mid] == offset)
+               {
+                 memmove (pstr->wcs, pstr->wcs + offset,
+                          (pstr->valid_len - offset) * sizeof (wint_t));
+                 memmove (pstr->mbs, pstr->mbs + offset, pstr->valid_len - 
offset);
+                 pstr->valid_len -= offset;
+                 pstr->valid_raw_len -= offset;
+                 for (low = 0; low < pstr->valid_len; low++)
+                   pstr->offsets[low] = pstr->offsets[low + offset] - offset;
+               }
+             else
+               {
+                 /* Otherwise, just find out how long the partial multibyte
+                    character at offset is and fill it with WEOF/255.  */
+                 pstr->len = pstr->raw_len - idx + offset;
+                 pstr->stop = pstr->raw_stop - idx + offset;
+                 pstr->offsets_needed = 0;
+                 while (mid > 0 && pstr->offsets[mid - 1] == offset)
+                   --mid;
+                 while (mid < pstr->valid_len)
+                   if (pstr->wcs[mid] != WEOF)
+                     break;
+                   else
+                     ++mid;
+                 if (mid == pstr->valid_len)
+                   pstr->valid_len = 0;
+                 else
+                   {
+                     pstr->valid_len = pstr->offsets[mid] - offset;
+                     if (pstr->valid_len)
+                       {
+                         for (low = 0; low < pstr->valid_len; ++low)
+                           pstr->wcs[low] = WEOF;
+                         memset (pstr->mbs, 255, pstr->valid_len);
+                       }
+                   }
+                 pstr->valid_raw_len = pstr->valid_len;
+               }
+           }
+         else
+#endif
+           {
+             pstr->tip_context = re_string_context_at (pstr, offset - 1,
+                                                       eflags);
+#ifdef RE_ENABLE_I18N
+             if (pstr->mb_cur_max > 1)
+               memmove (pstr->wcs, pstr->wcs + offset,
+                        (pstr->valid_len - offset) * sizeof (wint_t));
+#endif /* RE_ENABLE_I18N */
+             if (BE (pstr->mbs_allocated, 0))
+               memmove (pstr->mbs, pstr->mbs + offset,
+                        pstr->valid_len - offset);
+             pstr->valid_len -= offset;
+             pstr->valid_raw_len -= offset;
+#if DEBUG
+             assert (pstr->valid_len > 0);
+#endif
+           }
+       }
+      else
+       {
+#ifdef RE_ENABLE_I18N
+         /* No, skip all characters until IDX.  */
+         Idx prev_valid_len = pstr->valid_len;
+
+         if (BE (pstr->offsets_needed, 0))
+           {
+             pstr->len = pstr->raw_len - idx + offset;
+             pstr->stop = pstr->raw_stop - idx + offset;
+             pstr->offsets_needed = 0;
+           }
+#endif
+         pstr->valid_len = 0;
+#ifdef RE_ENABLE_I18N
+         if (pstr->mb_cur_max > 1)
+           {
+             Idx wcs_idx;
+             wint_t wc = WEOF;
+
+             if (pstr->is_utf8)
+               {
+                 const unsigned char *raw, *p, *end;
+
+                 /* Special case UTF-8.  Multi-byte chars start with any
+                    byte other than 0x80 - 0xbf.  */
+                 raw = pstr->raw_mbs + pstr->raw_mbs_idx;
+                 end = raw + (offset - pstr->mb_cur_max);
+                 if (end < pstr->raw_mbs)
+                   end = pstr->raw_mbs;
+                 p = raw + offset - 1;
+#ifdef _LIBC
+                 /* We know the wchar_t encoding is UCS4, so for the simple
+                    case, ASCII characters, skip the conversion step.  */
+                 if (isascii (*p) && BE (pstr->trans == NULL, 1))
+                   {
+                     memset (&pstr->cur_state, '\0', sizeof (mbstate_t));
+                     /* pstr->valid_len = 0; */
+                     wc = (wchar_t) *p;
+                   }
+                 else
+#endif
+                   for (; p >= end; --p)
+                     if ((*p & 0xc0) != 0x80)
+                       {
+                         mbstate_t cur_state;
+                         wchar_t wc2;
+                         Idx mlen = raw + pstr->len - p;
+                         size_t mbclen;
+
+#if 0 /* dead code: buf is set but never used */
+                         unsigned char buf[6];
+                         if (BE (pstr->trans != NULL, 0))
+                           {
+                             int i = mlen < 6 ? mlen : 6;
+                             while (--i >= 0)
+                               buf[i] = pstr->trans[p[i]];
+                           }
+#endif
+                         /* XXX Don't use mbrtowc, we know which conversion
+                            to use (UTF-8 -> UCS4).  */
+                         memset (&cur_state, 0, sizeof (cur_state));
+                         mbclen = __mbrtowc (&wc2, (const char *) p, mlen,
+                                             &cur_state);
+                         if (raw + offset - p <= mbclen
+                             && mbclen < (size_t) -2)
+                           {
+                             memset (&pstr->cur_state, '\0',
+                                     sizeof (mbstate_t));
+                             pstr->valid_len = mbclen - (raw + offset - p);
+                             wc = wc2;
+                           }
+                         break;
+                       }
+               }
+
+             if (wc == WEOF)
+               pstr->valid_len = re_string_skip_chars (pstr, idx, &wc) - idx;
+             if (wc == WEOF)
+               pstr->tip_context
+                 = re_string_context_at (pstr, prev_valid_len - 1, eflags);
+             else
+               pstr->tip_context = ((BE (pstr->word_ops_used != 0, 0)
+                                     && IS_WIDE_WORD_CHAR (wc))
+                                    ? CONTEXT_WORD
+                                    : ((IS_WIDE_NEWLINE (wc)
+                                        && pstr->newline_anchor)
+                                       ? CONTEXT_NEWLINE : 0));
+             if (BE (pstr->valid_len, 0))
+               {
+                 for (wcs_idx = 0; wcs_idx < pstr->valid_len; ++wcs_idx)
+                   pstr->wcs[wcs_idx] = WEOF;
+                 if (pstr->mbs_allocated)
+                   memset (pstr->mbs, 255, pstr->valid_len);
+               }
+             pstr->valid_raw_len = pstr->valid_len;
+           }
+         else
+#endif /* RE_ENABLE_I18N */
+           {
+             int c = pstr->raw_mbs[pstr->raw_mbs_idx + offset - 1];
+             pstr->valid_raw_len = 0;
+             if (pstr->trans)
+               c = pstr->trans[c];
+             pstr->tip_context = (bitset_contain (pstr->word_char, c)
+                                  ? CONTEXT_WORD
+                                  : ((IS_NEWLINE (c) && pstr->newline_anchor)
+                                     ? CONTEXT_NEWLINE : 0));
+           }
+       }
+      if (!BE (pstr->mbs_allocated, 0))
+       pstr->mbs += offset;
+    }
+  pstr->raw_mbs_idx = idx;
+  pstr->len -= offset;
+  pstr->stop -= offset;
+
+  /* Then build the buffers.  */
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1)
+    {
+      if (pstr->icase)
+       {
+         reg_errcode_t ret = build_wcs_upper_buffer (pstr);
+         if (BE (ret != REG_NOERROR, 0))
+           return ret;
+       }
+      else
+       build_wcs_buffer (pstr);
+    }
+  else
+#endif /* RE_ENABLE_I18N */
+    if (BE (pstr->mbs_allocated, 0))
+      {
+       if (pstr->icase)
+         build_upper_buffer (pstr);
+       else if (pstr->trans != NULL)
+         re_string_translate_buffer (pstr);
+      }
+    else
+      pstr->valid_len = pstr->len;
+
+  pstr->cur_idx = 0;
+  return REG_NOERROR;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_peek_byte_case (const re_string_t *pstr, Idx idx)
+{
+  int ch;
+  Idx off;
+
+  /* Handle the common (easiest) cases first.  */
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_peek_byte (pstr, idx);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->mb_cur_max > 1
+      && ! re_string_is_single_byte_char (pstr, pstr->cur_idx + idx))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  off = pstr->cur_idx + idx;
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    off = pstr->offsets[off];
+#endif
+
+  ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+#ifdef RE_ENABLE_I18N
+  /* Ensure that e.g. for tr_TR.UTF-8 BACKSLASH DOTLESS SMALL LETTER I
+     this function returns CAPITAL LETTER I instead of first byte of
+     DOTLESS SMALL LETTER I.  The latter would confuse the parser,
+     since peek_byte_case doesn't advance cur_idx in any way.  */
+  if (pstr->offsets_needed && !isascii (ch))
+    return re_string_peek_byte (pstr, idx);
+#endif
+
+  return ch;
+}
+
+static unsigned char
+internal_function __attribute ((pure))
+re_string_fetch_byte_case (re_string_t *pstr)
+{
+  if (BE (!pstr->mbs_allocated, 1))
+    return re_string_fetch_byte (pstr);
+
+#ifdef RE_ENABLE_I18N
+  if (pstr->offsets_needed)
+    {
+      Idx off;
+      int ch;
+
+      /* For tr_TR.UTF-8 [[:islower:]] there is
+        [[: CAPITAL LETTER I WITH DOT lower:]] in mbs.  Skip
+        in that case the whole multi-byte character and return
+        the original letter.  On the other side, with
+        [[: DOTLESS SMALL LETTER I return [[:I, as doing
+        anything else would complicate things too much.  */
+
+      if (!re_string_first_byte (pstr, pstr->cur_idx))
+       return re_string_fetch_byte (pstr);
+
+      off = pstr->offsets[pstr->cur_idx];
+      ch = pstr->raw_mbs[pstr->raw_mbs_idx + off];
+
+      if (! isascii (ch))
+       return re_string_fetch_byte (pstr);
+
+      re_string_skip_bytes (pstr,
+                           re_string_char_size_at (pstr, pstr->cur_idx));
+      return ch;
+    }
+#endif
+
+  return pstr->raw_mbs[pstr->raw_mbs_idx + pstr->cur_idx++];
+}
+
+static void
+internal_function
+re_string_destruct (re_string_t *pstr)
+{
+#ifdef RE_ENABLE_I18N
+  re_free (pstr->wcs);
+  re_free (pstr->offsets);
+#endif /* RE_ENABLE_I18N  */
+  if (pstr->mbs_allocated)
+    re_free (pstr->mbs);
+}
+
+/* Return the context at IDX in INPUT.  */
+
+static unsigned int
+internal_function
+re_string_context_at (const re_string_t *input, Idx idx, int eflags)
+{
+  int c;
+  if (BE (! REG_VALID_INDEX (idx), 0))
+    /* In this case, we use the value stored in input->tip_context,
+       since we can't know the character in input->mbs[-1] here.  */
+    return input->tip_context;
+  if (BE (idx == input->len, 0))
+    return ((eflags & REG_NOTEOL) ? CONTEXT_ENDBUF
+           : CONTEXT_NEWLINE | CONTEXT_ENDBUF);
+#ifdef RE_ENABLE_I18N
+  if (input->mb_cur_max > 1)
+    {
+      wint_t wc;
+      Idx wc_idx = idx;
+      while(input->wcs[wc_idx] == WEOF)
+       {
+#ifdef DEBUG
+         /* It must not happen.  */
+         assert (REG_VALID_INDEX (wc_idx));
+#endif
+         --wc_idx;
+         if (! REG_VALID_INDEX (wc_idx))
+           return input->tip_context;
+       }
+      wc = input->wcs[wc_idx];
+      if (BE (input->word_ops_used != 0, 0) && IS_WIDE_WORD_CHAR (wc))
+       return CONTEXT_WORD;
+      return (IS_WIDE_NEWLINE (wc) && input->newline_anchor
+             ? CONTEXT_NEWLINE : 0);
+    }
+  else
+#endif
+    {
+      c = re_string_byte_at (input, idx);
+      if (bitset_contain (input->word_char, c))
+       return CONTEXT_WORD;
+      return IS_NEWLINE (c) && input->newline_anchor ? CONTEXT_NEWLINE : 0;
+    }
+}
+
+/* Functions for set operation.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_alloc (re_node_set *set, Idx size)
+{
+  set->alloc = size;
+  set->nelem = 0;
+  set->elems = re_malloc (Idx, size);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_init_1 (re_node_set *set, Idx elem)
+{
+  set->alloc = 1;
+  set->nelem = 1;
+  set->elems = re_malloc (Idx, 1);
+  if (BE (set->elems == NULL, 0))
+    {
+      set->alloc = set->nelem = 0;
+      return REG_ESPACE;
+    }
+  set->elems[0] = elem;
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_init_2 (re_node_set *set, Idx elem1, Idx elem2)
+{
+  set->alloc = 2;
+  set->elems = re_malloc (Idx, 2);
+  if (BE (set->elems == NULL, 0))
+    return REG_ESPACE;
+  if (elem1 == elem2)
+    {
+      set->nelem = 1;
+      set->elems[0] = elem1;
+    }
+  else
+    {
+      set->nelem = 2;
+      if (elem1 < elem2)
+       {
+         set->elems[0] = elem1;
+         set->elems[1] = elem2;
+       }
+      else
+       {
+         set->elems[0] = elem2;
+         set->elems[1] = elem1;
+       }
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_init_copy (re_node_set *dest, const re_node_set *src)
+{
+  dest->nelem = src->nelem;
+  if (src->nelem > 0)
+    {
+      dest->alloc = dest->nelem;
+      dest->elems = re_malloc (Idx, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+       {
+         dest->alloc = dest->nelem = 0;
+         return REG_ESPACE;
+       }
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (Idx));
+    }
+  else
+    re_node_set_init_empty (dest);
+  return REG_NOERROR;
+}
+
+/* Calculate the intersection of the sets SRC1 and SRC2. And merge it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.
+   Note: We assume dest->elems is NULL, when dest->alloc is 0.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_add_intersect (re_node_set *dest, const re_node_set *src1,
+                          const re_node_set *src2)
+{
+  Idx i1, i2, is, id, delta, sbase;
+  if (src1->nelem == 0 || src2->nelem == 0)
+    return REG_NOERROR;
+
+  /* We need dest->nelem + 2 * elems_in_intersection; this is a
+     conservative estimate.  */
+  if (src1->nelem + src2->nelem + dest->nelem > dest->alloc)
+    {
+      Idx new_alloc = src1->nelem + src2->nelem + dest->alloc;
+      Idx *new_elems = re_realloc (dest->elems, Idx, new_alloc);
+      if (BE (new_elems == NULL, 0))
+       return REG_ESPACE;
+      dest->elems = new_elems;
+      dest->alloc = new_alloc;
+    }
+
+  /* Find the items in the intersection of SRC1 and SRC2, and copy
+     into the top of DEST those that are not already in DEST itself.  */
+  sbase = dest->nelem + src1->nelem + src2->nelem;
+  i1 = src1->nelem - 1;
+  i2 = src2->nelem - 1;
+  id = dest->nelem - 1;
+  for (;;)
+    {
+      if (src1->elems[i1] == src2->elems[i2])
+       {
+         /* Try to find the item in DEST.  Maybe we could binary search?  */
+         while (REG_VALID_INDEX (id) && dest->elems[id] > src1->elems[i1])
+           --id;
+
+          if (! REG_VALID_INDEX (id) || dest->elems[id] != src1->elems[i1])
+            dest->elems[--sbase] = src1->elems[i1];
+
+         if (! REG_VALID_INDEX (--i1) || ! REG_VALID_INDEX (--i2))
+           break;
+       }
+
+      /* Lower the highest of the two items.  */
+      else if (src1->elems[i1] < src2->elems[i2])
+       {
+         if (! REG_VALID_INDEX (--i2))
+           break;
+       }
+      else
+       {
+         if (! REG_VALID_INDEX (--i1))
+           break;
+       }
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + src1->nelem + src2->nelem - 1;
+  delta = is - sbase + 1;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place; this is more or
+     less the same loop that is in re_node_set_merge.  */
+  dest->nelem += delta;
+  if (delta > 0 && REG_VALID_INDEX (id))
+    for (;;)
+      {
+       if (dest->elems[is] > dest->elems[id])
+         {
+           /* Copy from the top.  */
+           dest->elems[id + delta--] = dest->elems[is--];
+           if (delta == 0)
+             break;
+         }
+       else
+         {
+           /* Slide from the bottom.  */
+           dest->elems[id + delta] = dest->elems[id];
+           if (! REG_VALID_INDEX (--id))
+             break;
+         }
+      }
+
+  /* Copy remaining SRC elements.  */
+  memcpy (dest->elems, dest->elems + sbase, delta * sizeof (Idx));
+
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets SRC1 and SRC2. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_init_union (re_node_set *dest, const re_node_set *src1,
+                       const re_node_set *src2)
+{
+  Idx i1, i2, id;
+  if (src1 != NULL && src1->nelem > 0 && src2 != NULL && src2->nelem > 0)
+    {
+      dest->alloc = src1->nelem + src2->nelem;
+      dest->elems = re_malloc (Idx, dest->alloc);
+      if (BE (dest->elems == NULL, 0))
+       return REG_ESPACE;
+    }
+  else
+    {
+      if (src1 != NULL && src1->nelem > 0)
+       return re_node_set_init_copy (dest, src1);
+      else if (src2 != NULL && src2->nelem > 0)
+       return re_node_set_init_copy (dest, src2);
+      else
+       re_node_set_init_empty (dest);
+      return REG_NOERROR;
+    }
+  for (i1 = i2 = id = 0 ; i1 < src1->nelem && i2 < src2->nelem ;)
+    {
+      if (src1->elems[i1] > src2->elems[i2])
+       {
+         dest->elems[id++] = src2->elems[i2++];
+         continue;
+       }
+      if (src1->elems[i1] == src2->elems[i2])
+       ++i2;
+      dest->elems[id++] = src1->elems[i1++];
+    }
+  if (i1 < src1->nelem)
+    {
+      memcpy (dest->elems + id, src1->elems + i1,
+            (src1->nelem - i1) * sizeof (Idx));
+      id += src1->nelem - i1;
+    }
+  else if (i2 < src2->nelem)
+    {
+      memcpy (dest->elems + id, src2->elems + i2,
+            (src2->nelem - i2) * sizeof (Idx));
+      id += src2->nelem - i2;
+    }
+  dest->nelem = id;
+  return REG_NOERROR;
+}
+
+/* Calculate the union set of the sets DEST and SRC. And store it to
+   DEST. Return value indicate the error code or REG_NOERROR if succeeded.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_node_set_merge (re_node_set *dest, const re_node_set *src)
+{
+  Idx is, id, sbase, delta;
+  if (src == NULL || src->nelem == 0)
+    return REG_NOERROR;
+  if (dest->alloc < 2 * src->nelem + dest->nelem)
+    {
+      Idx new_alloc = 2 * (src->nelem + dest->alloc);
+      Idx *new_buffer = re_realloc (dest->elems, Idx, new_alloc);
+      if (BE (new_buffer == NULL, 0))
+       return REG_ESPACE;
+      dest->elems = new_buffer;
+      dest->alloc = new_alloc;
+    }
+
+  if (BE (dest->nelem == 0, 0))
+    {
+      dest->nelem = src->nelem;
+      memcpy (dest->elems, src->elems, src->nelem * sizeof (Idx));
+      return REG_NOERROR;
+    }
+
+  /* Copy into the top of DEST the items of SRC that are not
+     found in DEST.  Maybe we could binary search in DEST?  */
+  for (sbase = dest->nelem + 2 * src->nelem,
+       is = src->nelem - 1, id = dest->nelem - 1;
+       REG_VALID_INDEX (is) && REG_VALID_INDEX (id); )
+    {
+      if (dest->elems[id] == src->elems[is])
+       is--, id--;
+      else if (dest->elems[id] < src->elems[is])
+       dest->elems[--sbase] = src->elems[is--];
+      else /* if (dest->elems[id] > src->elems[is]) */
+       --id;
+    }
+
+  if (REG_VALID_INDEX (is))
+    {
+      /* If DEST is exhausted, the remaining items of SRC must be unique.  */
+      sbase -= is + 1;
+      memcpy (dest->elems + sbase, src->elems, (is + 1) * sizeof (Idx));
+    }
+
+  id = dest->nelem - 1;
+  is = dest->nelem + 2 * src->nelem - 1;
+  delta = is - sbase + 1;
+  if (delta == 0)
+    return REG_NOERROR;
+
+  /* Now copy.  When DELTA becomes zero, the remaining
+     DEST elements are already in place.  */
+  dest->nelem += delta;
+  for (;;)
+    {
+      if (dest->elems[is] > dest->elems[id])
+       {
+         /* Copy from the top.  */
+         dest->elems[id + delta--] = dest->elems[is--];
+         if (delta == 0)
+           break;
+       }
+      else
+       {
+         /* Slide from the bottom.  */
+         dest->elems[id + delta] = dest->elems[id];
+         if (! REG_VALID_INDEX (--id))
+           {
+             /* Copy remaining SRC elements.  */
+             memcpy (dest->elems, dest->elems + sbase,
+                     delta * sizeof (Idx));
+             break;
+           }
+       }
+    }
+
+  return REG_NOERROR;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have ELEM.
+   Return true if successful.  */
+
+static bool
+internal_function __attribute_warn_unused_result__
+re_node_set_insert (re_node_set *set, Idx elem)
+{
+  Idx idx;
+  /* In case the set is empty.  */
+  if (set->alloc == 0)
+    return BE (re_node_set_init_1 (set, elem) == REG_NOERROR, 1);
+
+  if (BE (set->nelem, 0) == 0)
+    {
+      /* We already guaranteed above that set->alloc != 0.  */
+      set->elems[0] = elem;
+      ++set->nelem;
+      return true;
+    }
+
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      Idx *new_elems;
+      set->alloc = set->alloc * 2;
+      new_elems = re_realloc (set->elems, Idx, set->alloc);
+      if (BE (new_elems == NULL, 0))
+       return false;
+      set->elems = new_elems;
+    }
+
+  /* Move the elements which follows the new element.  Test the
+     first element separately to skip a check in the inner loop.  */
+  if (elem < set->elems[0])
+    {
+      idx = 0;
+      for (idx = set->nelem; idx > 0; idx--)
+       set->elems[idx] = set->elems[idx - 1];
+    }
+  else
+    {
+      for (idx = set->nelem; set->elems[idx - 1] > elem; idx--)
+       set->elems[idx] = set->elems[idx - 1];
+    }
+
+  /* Insert the new element.  */
+  set->elems[idx] = elem;
+  ++set->nelem;
+  return true;
+}
+
+/* Insert the new element ELEM to the re_node_set* SET.
+   SET should not already have any element greater than or equal to ELEM.
+   Return true if successful.  */
+
+static bool
+internal_function __attribute_warn_unused_result__
+re_node_set_insert_last (re_node_set *set, Idx elem)
+{
+  /* Realloc if we need.  */
+  if (set->alloc == set->nelem)
+    {
+      Idx *new_elems;
+      set->alloc = (set->alloc + 1) * 2;
+      new_elems = re_realloc (set->elems, Idx, set->alloc);
+      if (BE (new_elems == NULL, 0))
+       return false;
+      set->elems = new_elems;
+    }
+
+  /* Insert the new element.  */
+  set->elems[set->nelem++] = elem;
+  return true;
+}
+
+/* Compare two node sets SET1 and SET2.
+   Return true if SET1 and SET2 are equivalent.  */
+
+static bool
+internal_function __attribute ((pure))
+re_node_set_compare (const re_node_set *set1, const re_node_set *set2)
+{
+  Idx i;
+  if (set1 == NULL || set2 == NULL || set1->nelem != set2->nelem)
+    return false;
+  for (i = set1->nelem ; REG_VALID_INDEX (--i) ; )
+    if (set1->elems[i] != set2->elems[i])
+      return false;
+  return true;
+}
+
+/* Return (idx + 1) if SET contains the element ELEM, return 0 otherwise.  */
+
+static Idx
+internal_function __attribute ((pure))
+re_node_set_contains (const re_node_set *set, Idx elem)
+{
+  __re_size_t idx, right, mid;
+  if (! REG_VALID_NONZERO_INDEX (set->nelem))
+    return 0;
+
+  /* Binary search the element.  */
+  idx = 0;
+  right = set->nelem - 1;
+  while (idx < right)
+    {
+      mid = (idx + right) / 2;
+      if (set->elems[mid] < elem)
+       idx = mid + 1;
+      else
+       right = mid;
+    }
+  return set->elems[idx] == elem ? idx + 1 : 0;
+}
+
+static void
+internal_function
+re_node_set_remove_at (re_node_set *set, Idx idx)
+{
+  if (idx < 0 || idx >= set->nelem)
+    return;
+  --set->nelem;
+  for (; idx < set->nelem; idx++)
+    set->elems[idx] = set->elems[idx + 1];
+}
+
+
+/* Add the token TOKEN to dfa->nodes, and return the index of the token.
+   Or return REG_MISSING if an error occurred.  */
+
+static Idx
+internal_function
+re_dfa_add_node (re_dfa_t *dfa, re_token_t token)
+{
+  if (BE (dfa->nodes_len >= dfa->nodes_alloc, 0))
+    {
+      size_t new_nodes_alloc = dfa->nodes_alloc * 2;
+      Idx *new_nexts, *new_indices;
+      re_node_set *new_edests, *new_eclosures;
+      re_token_t *new_nodes;
+      size_t max_object_size =
+       MAX (sizeof (re_token_t),
+            MAX (sizeof (re_node_set),
+                 sizeof (Idx)));
+
+      /* Avoid overflows.  */
+      if (BE (SIZE_MAX / 2 / max_object_size < dfa->nodes_alloc, 0))
+       return REG_MISSING;
+
+      new_nodes = re_realloc (dfa->nodes, re_token_t, new_nodes_alloc);
+      if (BE (new_nodes == NULL, 0))
+       return REG_MISSING;
+      dfa->nodes = new_nodes;
+      new_nexts = re_realloc (dfa->nexts, Idx, new_nodes_alloc);
+      new_indices = re_realloc (dfa->org_indices, Idx, new_nodes_alloc);
+      new_edests = re_realloc (dfa->edests, re_node_set, new_nodes_alloc);
+      new_eclosures = re_realloc (dfa->eclosures, re_node_set, 
new_nodes_alloc);
+      if (BE (new_nexts == NULL || new_indices == NULL
+             || new_edests == NULL || new_eclosures == NULL, 0))
+       return REG_MISSING;
+      dfa->nexts = new_nexts;
+      dfa->org_indices = new_indices;
+      dfa->edests = new_edests;
+      dfa->eclosures = new_eclosures;
+      dfa->nodes_alloc = new_nodes_alloc;
+    }
+  dfa->nodes[dfa->nodes_len] = token;
+  dfa->nodes[dfa->nodes_len].constraint = 0;
+#ifdef RE_ENABLE_I18N
+  {
+  int type = token.type;
+  dfa->nodes[dfa->nodes_len].accept_mb =
+    (type == OP_PERIOD && dfa->mb_cur_max > 1) || type == COMPLEX_BRACKET;
+  }
+#endif
+  dfa->nexts[dfa->nodes_len] = REG_MISSING;
+  re_node_set_init_empty (dfa->edests + dfa->nodes_len);
+  re_node_set_init_empty (dfa->eclosures + dfa->nodes_len);
+  return dfa->nodes_len++;
+}
+
+static inline re_hashval_t
+internal_function
+calc_state_hash (const re_node_set *nodes, unsigned int context)
+{
+  re_hashval_t hash = nodes->nelem + context;
+  Idx i;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    hash += nodes->elems[i];
+  return hash;
+}
+
+/* Search for the state whose node_set is equivalent to NODES.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+          return value is NULL and ERR is REG_NOERROR.
+        - We never return non-NULL value in case of any errors, it is for
+          optimization.  */
+
+static re_dfastate_t *
+internal_function __attribute_warn_unused_result__
+re_acquire_state (reg_errcode_t *err, const re_dfa_t *dfa,
+                 const re_node_set *nodes)
+{
+  re_hashval_t hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  Idx i;
+#ifdef lint
+  /* Suppress bogus uninitialized-variable warnings.  */
+  *err = REG_NOERROR;
+#endif
+  if (BE (nodes->nelem == 0, 0))
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, 0);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (hash != state->hash)
+       continue;
+      if (re_node_set_compare (&state->nodes, nodes))
+       return state;
+    }
+
+  /* There are no appropriate state in the dfa, create the new one.  */
+  new_state = create_ci_newstate (dfa, nodes, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Search for the state whose node_set is equivalent to NODES and
+   whose context is equivalent to CONTEXT.
+   Return the pointer to the state, if we found it in the DFA.
+   Otherwise create the new one and return it.  In case of an error
+   return NULL and set the error code in ERR.
+   Note: - We assume NULL as the invalid state, then it is possible that
+          return value is NULL and ERR is REG_NOERROR.
+        - We never return non-NULL value in case of any errors, it is for
+          optimization.  */
+
+static re_dfastate_t *
+internal_function __attribute_warn_unused_result__
+re_acquire_state_context (reg_errcode_t *err, const re_dfa_t *dfa,
+                         const re_node_set *nodes, unsigned int context)
+{
+  re_hashval_t hash;
+  re_dfastate_t *new_state;
+  struct re_state_table_entry *spot;
+  Idx i;
+#ifdef lint
+  /* Suppress bogus uninitialized-variable warnings.  */
+  *err = REG_NOERROR;
+#endif
+  if (nodes->nelem == 0)
+    {
+      *err = REG_NOERROR;
+      return NULL;
+    }
+  hash = calc_state_hash (nodes, context);
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+
+  for (i = 0 ; i < spot->num ; i++)
+    {
+      re_dfastate_t *state = spot->array[i];
+      if (state->hash == hash
+         && state->context == context
+         && re_node_set_compare (state->entrance_nodes, nodes))
+       return state;
+    }
+  /* There are no appropriate state in 'dfa', create the new one.  */
+  new_state = create_cd_newstate (dfa, nodes, context, hash);
+  if (BE (new_state == NULL, 0))
+    *err = REG_ESPACE;
+
+  return new_state;
+}
+
+/* Finish initialization of the new state NEWSTATE, and using its hash value
+   HASH put in the appropriate bucket of DFA's state table.  Return value
+   indicates the error code if failed.  */
+
+static reg_errcode_t
+__attribute_warn_unused_result__
+register_state (const re_dfa_t *dfa, re_dfastate_t *newstate,
+               re_hashval_t hash)
+{
+  struct re_state_table_entry *spot;
+  reg_errcode_t err;
+  Idx i;
+
+  newstate->hash = hash;
+  err = re_node_set_alloc (&newstate->non_eps_nodes, newstate->nodes.nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return REG_ESPACE;
+  for (i = 0; i < newstate->nodes.nelem; i++)
+    {
+      Idx elem = newstate->nodes.elems[i];
+      if (!IS_EPSILON_NODE (dfa->nodes[elem].type))
+       if (BE (! re_node_set_insert_last (&newstate->non_eps_nodes, elem), 0))
+         return REG_ESPACE;
+    }
+
+  spot = dfa->state_table + (hash & dfa->state_hash_mask);
+  if (BE (spot->alloc <= spot->num, 0))
+    {
+      Idx new_alloc = 2 * spot->num + 2;
+      re_dfastate_t **new_array = re_realloc (spot->array, re_dfastate_t *,
+                                             new_alloc);
+      if (BE (new_array == NULL, 0))
+       return REG_ESPACE;
+      spot->array = new_array;
+      spot->alloc = new_alloc;
+    }
+  spot->array[spot->num++] = newstate;
+  return REG_NOERROR;
+}
+
+static void
+free_state (re_dfastate_t *state)
+{
+  re_node_set_free (&state->non_eps_nodes);
+  re_node_set_free (&state->inveclosure);
+  if (state->entrance_nodes != &state->nodes)
+    {
+      re_node_set_free (state->entrance_nodes);
+      re_free (state->entrance_nodes);
+    }
+  re_node_set_free (&state->nodes);
+  re_free (state->word_trtable);
+  re_free (state->trtable);
+  re_free (state);
+}
+
+/* Create the new state which is independ of contexts.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function __attribute_warn_unused_result__
+create_ci_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+                   re_hashval_t hash)
+{
+  Idx i;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->entrance_nodes = &newstate->nodes;
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      if (type == CHARACTER && !node->constraint)
+       continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+       newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+       newstate->has_backref = 1;
+      else if (type == ANCHOR || node->constraint)
+       newstate->has_constraint = 1;
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return newstate;
+}
+
+/* Create the new state which is depend on the context CONTEXT.
+   Return the new state if succeeded, otherwise return NULL.  */
+
+static re_dfastate_t *
+internal_function __attribute_warn_unused_result__
+create_cd_newstate (const re_dfa_t *dfa, const re_node_set *nodes,
+                   unsigned int context, re_hashval_t hash)
+{
+  Idx i, nctx_nodes = 0;
+  reg_errcode_t err;
+  re_dfastate_t *newstate;
+
+  newstate = (re_dfastate_t *) calloc (sizeof (re_dfastate_t), 1);
+  if (BE (newstate == NULL, 0))
+    return NULL;
+  err = re_node_set_init_copy (&newstate->nodes, nodes);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      re_free (newstate);
+      return NULL;
+    }
+
+  newstate->context = context;
+  newstate->entrance_nodes = &newstate->nodes;
+
+  for (i = 0 ; i < nodes->nelem ; i++)
+    {
+      re_token_t *node = dfa->nodes + nodes->elems[i];
+      re_token_type_t type = node->type;
+      unsigned int constraint = node->constraint;
+
+      if (type == CHARACTER && !constraint)
+       continue;
+#ifdef RE_ENABLE_I18N
+      newstate->accept_mb |= node->accept_mb;
+#endif /* RE_ENABLE_I18N */
+
+      /* If the state has the halt node, the state is a halt state.  */
+      if (type == END_OF_RE)
+       newstate->halt = 1;
+      else if (type == OP_BACK_REF)
+       newstate->has_backref = 1;
+
+      if (constraint)
+       {
+         if (newstate->entrance_nodes == &newstate->nodes)
+           {
+             newstate->entrance_nodes = re_malloc (re_node_set, 1);
+             if (BE (newstate->entrance_nodes == NULL, 0))
+               {
+                 free_state (newstate);
+                 return NULL;
+               }
+             if (re_node_set_init_copy (newstate->entrance_nodes, nodes)
+                 != REG_NOERROR)
+               return NULL;
+             nctx_nodes = 0;
+             newstate->has_constraint = 1;
+           }
+
+         if (NOT_SATISFY_PREV_CONSTRAINT (constraint,context))
+           {
+             re_node_set_remove_at (&newstate->nodes, i - nctx_nodes);
+             ++nctx_nodes;
+           }
+       }
+    }
+  err = register_state (dfa, newstate, hash);
+  if (BE (err != REG_NOERROR, 0))
+    {
+      free_state (newstate);
+      newstate = NULL;
+    }
+  return  newstate;
+}
diff --git a/lib/regex_internal.h b/lib/regex_internal.h
new file mode 100644
index 0000000..7261192
--- /dev/null
+++ b/lib/regex_internal.h
@@ -0,0 +1,866 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <address@hidden>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifndef _REGEX_INTERNAL_H
+#define _REGEX_INTERNAL_H 1
+
+#include <assert.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <langinfo.h>
+#ifndef _LIBC
+# include "localcharset.h"
+#endif
+#include <locale.h>
+
+#include <wchar.h>
+#include <wctype.h>
+#include <stdint.h>
+#if defined _LIBC
+# include <bits/libc-lock.h>
+#else
+# define __libc_lock_init(NAME) do { } while (0)
+# define __libc_lock_lock(NAME) do { } while (0)
+# define __libc_lock_unlock(NAME) do { } while (0)
+#endif
+
+/* In case that the system doesn't have isblank().  */
+#if !defined _LIBC && ! (defined isblank || (HAVE_ISBLANK && 
HAVE_DECL_ISBLANK))
+# define isblank(ch) ((ch) == ' ' || (ch) == '\t')
+#endif
+
+#ifdef _LIBC
+# ifndef _RE_DEFINE_LOCALE_FUNCTIONS
+#  define _RE_DEFINE_LOCALE_FUNCTIONS 1
+#   include <locale/localeinfo.h>
+#   include <locale/elem-hash.h>
+#   include <locale/coll-lookup.h>
+# endif
+#endif
+
+/* This is for other GNU distributions with internationalized messages.  */
+#if (HAVE_LIBINTL_H && ENABLE_NLS) || defined _LIBC
+# include <libintl.h>
+# ifdef _LIBC
+#  undef gettext
+#  define gettext(msgid) \
+  INTUSE(__dcgettext) (_libc_intl_domainname, msgid, LC_MESSAGES)
+# endif
+#else
+# define gettext(msgid) (msgid)
+#endif
+
+#ifndef gettext_noop
+/* This define is so xgettext can find the internationalizable
+   strings.  */
+# define gettext_noop(String) String
+#endif
+
+/* For loser systems without the definition.  */
+#ifndef SIZE_MAX
+# define SIZE_MAX ((size_t) -1)
+#endif
+
+#if (defined MB_CUR_MAX && HAVE_WCTYPE_H && HAVE_ISWCTYPE && HAVE_WCSCOLL) || 
_LIBC
+# define RE_ENABLE_I18N
+#endif
+
+#if __GNUC__ >= 3
+# define BE(expr, val) __builtin_expect (expr, val)
+#else
+# define BE(expr, val) (expr)
+# ifdef _LIBC
+#  define inline
+# endif
+#endif
+
+/* Number of ASCII characters.  */
+#define ASCII_CHARS 0x80
+
+/* Number of single byte characters.  */
+#define SBC_MAX (UCHAR_MAX + 1)
+
+#define COLL_ELEM_LEN_MAX 8
+
+/* The character which represents newline.  */
+#define NEWLINE_CHAR '\n'
+#define WIDE_NEWLINE_CHAR L'\n'
+
+/* Rename to standard API for using out of glibc.  */
+#ifndef _LIBC
+# define __wctype wctype
+# define __iswctype iswctype
+# define __btowc btowc
+# define __wcrtomb wcrtomb
+# define __mbrtowc mbrtowc
+# define __regfree regfree
+# define attribute_hidden
+#endif /* not _LIBC */
+
+#if __GNUC__ >= 4 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1)
+# define __attribute(arg) __attribute__ (arg)
+#else
+# define __attribute(arg)
+#endif
+
+typedef __re_idx_t Idx;
+
+/* Special return value for failure to match.  */
+#define REG_MISSING ((Idx) -1)
+
+/* Special return value for internal error.  */
+#define REG_ERROR ((Idx) -2)
+
+/* Test whether N is a valid index, and is not one of the above.  */
+#ifdef _REGEX_LARGE_OFFSETS
+# define REG_VALID_INDEX(n) ((Idx) (n) < REG_ERROR)
+#else
+# define REG_VALID_INDEX(n) (0 <= (n))
+#endif
+
+/* Test whether N is a valid nonzero index.  */
+#ifdef _REGEX_LARGE_OFFSETS
+# define REG_VALID_NONZERO_INDEX(n) ((Idx) ((n) - 1) < (Idx) (REG_ERROR - 1))
+#else
+# define REG_VALID_NONZERO_INDEX(n) (0 < (n))
+#endif
+
+/* A hash value, suitable for computing hash tables.  */
+typedef __re_size_t re_hashval_t;
+
+/* An integer used to represent a set of bits.  It must be unsigned,
+   and must be at least as wide as unsigned int.  */
+typedef unsigned long int bitset_word_t;
+/* All bits set in a bitset_word_t.  */
+#define BITSET_WORD_MAX ULONG_MAX
+
+/* Number of bits in a bitset_word_t.  For portability to hosts with
+   padding bits, do not use '(sizeof (bitset_word_t) * CHAR_BIT)';
+   instead, deduce it directly from BITSET_WORD_MAX.  Avoid
+   greater-than-32-bit integers and unconditional shifts by more than
+   31 bits, as they're not portable.  */
+#if BITSET_WORD_MAX == 0xffffffffUL
+# define BITSET_WORD_BITS 32
+#elif BITSET_WORD_MAX >> 31 >> 4 == 1
+# define BITSET_WORD_BITS 36
+#elif BITSET_WORD_MAX >> 31 >> 16 == 1
+# define BITSET_WORD_BITS 48
+#elif BITSET_WORD_MAX >> 31 >> 28 == 1
+# define BITSET_WORD_BITS 60
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 1 == 1
+# define BITSET_WORD_BITS 64
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 9 == 1
+# define BITSET_WORD_BITS 72
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 3 == 1
+# define BITSET_WORD_BITS 128
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 == 1
+# define BITSET_WORD_BITS 256
+#elif BITSET_WORD_MAX >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 31 >> 7 > 1
+# define BITSET_WORD_BITS 257 /* any value > SBC_MAX will do here */
+# if BITSET_WORD_BITS <= SBC_MAX
+#  error "Invalid SBC_MAX"
+# endif
+#else
+# error "Add case for new bitset_word_t size"
+#endif
+
+/* Number of bitset_word_t values in a bitset_t.  */
+#define BITSET_WORDS ((SBC_MAX + BITSET_WORD_BITS - 1) / BITSET_WORD_BITS)
+
+typedef bitset_word_t bitset_t[BITSET_WORDS];
+typedef bitset_word_t *re_bitset_ptr_t;
+typedef const bitset_word_t *re_const_bitset_ptr_t;
+
+#define PREV_WORD_CONSTRAINT 0x0001
+#define PREV_NOTWORD_CONSTRAINT 0x0002
+#define NEXT_WORD_CONSTRAINT 0x0004
+#define NEXT_NOTWORD_CONSTRAINT 0x0008
+#define PREV_NEWLINE_CONSTRAINT 0x0010
+#define NEXT_NEWLINE_CONSTRAINT 0x0020
+#define PREV_BEGBUF_CONSTRAINT 0x0040
+#define NEXT_ENDBUF_CONSTRAINT 0x0080
+#define WORD_DELIM_CONSTRAINT 0x0100
+#define NOT_WORD_DELIM_CONSTRAINT 0x0200
+
+typedef enum
+{
+  INSIDE_WORD = PREV_WORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_FIRST = PREV_NOTWORD_CONSTRAINT | NEXT_WORD_CONSTRAINT,
+  WORD_LAST = PREV_WORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  INSIDE_NOTWORD = PREV_NOTWORD_CONSTRAINT | NEXT_NOTWORD_CONSTRAINT,
+  LINE_FIRST = PREV_NEWLINE_CONSTRAINT,
+  LINE_LAST = NEXT_NEWLINE_CONSTRAINT,
+  BUF_FIRST = PREV_BEGBUF_CONSTRAINT,
+  BUF_LAST = NEXT_ENDBUF_CONSTRAINT,
+  WORD_DELIM = WORD_DELIM_CONSTRAINT,
+  NOT_WORD_DELIM = NOT_WORD_DELIM_CONSTRAINT
+} re_context_type;
+
+typedef struct
+{
+  Idx alloc;
+  Idx nelem;
+  Idx *elems;
+} re_node_set;
+
+typedef enum
+{
+  NON_TYPE = 0,
+
+  /* Node type, These are used by token, node, tree.  */
+  CHARACTER = 1,
+  END_OF_RE = 2,
+  SIMPLE_BRACKET = 3,
+  OP_BACK_REF = 4,
+  OP_PERIOD = 5,
+#ifdef RE_ENABLE_I18N
+  COMPLEX_BRACKET = 6,
+  OP_UTF8_PERIOD = 7,
+#endif /* RE_ENABLE_I18N */
+
+  /* We define EPSILON_BIT as a macro so that OP_OPEN_SUBEXP is used
+     when the debugger shows values of this enum type.  */
+#define EPSILON_BIT 8
+  OP_OPEN_SUBEXP = EPSILON_BIT | 0,
+  OP_CLOSE_SUBEXP = EPSILON_BIT | 1,
+  OP_ALT = EPSILON_BIT | 2,
+  OP_DUP_ASTERISK = EPSILON_BIT | 3,
+  ANCHOR = EPSILON_BIT | 4,
+
+  /* Tree type, these are used only by tree. */
+  CONCAT = 16,
+  SUBEXP = 17,
+
+  /* Token type, these are used only by token.  */
+  OP_DUP_PLUS = 18,
+  OP_DUP_QUESTION,
+  OP_OPEN_BRACKET,
+  OP_CLOSE_BRACKET,
+  OP_CHARSET_RANGE,
+  OP_OPEN_DUP_NUM,
+  OP_CLOSE_DUP_NUM,
+  OP_NON_MATCH_LIST,
+  OP_OPEN_COLL_ELEM,
+  OP_CLOSE_COLL_ELEM,
+  OP_OPEN_EQUIV_CLASS,
+  OP_CLOSE_EQUIV_CLASS,
+  OP_OPEN_CHAR_CLASS,
+  OP_CLOSE_CHAR_CLASS,
+  OP_WORD,
+  OP_NOTWORD,
+  OP_SPACE,
+  OP_NOTSPACE,
+  BACK_SLASH
+
+} re_token_type_t;
+
+#ifdef RE_ENABLE_I18N
+typedef struct
+{
+  /* Multibyte characters.  */
+  wchar_t *mbchars;
+
+  /* Collating symbols.  */
+# ifdef _LIBC
+  int32_t *coll_syms;
+# endif
+
+  /* Equivalence classes. */
+# ifdef _LIBC
+  int32_t *equiv_classes;
+# endif
+
+  /* Range expressions. */
+# ifdef _LIBC
+  uint32_t *range_starts;
+  uint32_t *range_ends;
+# else /* not _LIBC */
+  wchar_t *range_starts;
+  wchar_t *range_ends;
+# endif /* not _LIBC */
+
+  /* Character classes. */
+  wctype_t *char_classes;
+
+  /* If this character set is the non-matching list.  */
+  unsigned int non_match : 1;
+
+  /* # of multibyte characters.  */
+  Idx nmbchars;
+
+  /* # of collating symbols.  */
+  Idx ncoll_syms;
+
+  /* # of equivalence classes. */
+  Idx nequiv_classes;
+
+  /* # of range expressions. */
+  Idx nranges;
+
+  /* # of character classes. */
+  Idx nchar_classes;
+} re_charset_t;
+#endif /* RE_ENABLE_I18N */
+
+typedef struct
+{
+  union
+  {
+    unsigned char c;           /* for CHARACTER */
+    re_bitset_ptr_t sbcset;    /* for SIMPLE_BRACKET */
+#ifdef RE_ENABLE_I18N
+    re_charset_t *mbcset;      /* for COMPLEX_BRACKET */
+#endif /* RE_ENABLE_I18N */
+    Idx idx;                   /* for BACK_REF */
+    re_context_type ctx_type;  /* for ANCHOR */
+  } opr;
+#if __GNUC__ >= 2 && !defined __STRICT_ANSI__
+  re_token_type_t type : 8;
+#else
+  re_token_type_t type;
+#endif
+  unsigned int constraint : 10;        /* context constraint */
+  unsigned int duplicated : 1;
+  unsigned int opt_subexp : 1;
+#ifdef RE_ENABLE_I18N
+  unsigned int accept_mb : 1;
+  /* These 2 bits can be moved into the union if needed (e.g. if running out
+     of bits; move opr.c to opr.c.c and move the flags to opr.c.flags).  */
+  unsigned int mb_partial : 1;
+#endif
+  unsigned int word_char : 1;
+} re_token_t;
+
+#define IS_EPSILON_NODE(type) ((type) & EPSILON_BIT)
+
+struct re_string_t
+{
+  /* Indicate the raw buffer which is the original string passed as an
+     argument of regexec(), re_search(), etc..  */
+  const unsigned char *raw_mbs;
+  /* Store the multibyte string.  In case of "case insensitive mode" like
+     REG_ICASE, upper cases of the string are stored, otherwise MBS points
+     the same address that RAW_MBS points.  */
+  unsigned char *mbs;
+#ifdef RE_ENABLE_I18N
+  /* Store the wide character string which is corresponding to MBS.  */
+  wint_t *wcs;
+  Idx *offsets;
+  mbstate_t cur_state;
+#endif
+  /* Index in RAW_MBS.  Each character mbs[i] corresponds to
+     raw_mbs[raw_mbs_idx + i].  */
+  Idx raw_mbs_idx;
+  /* The length of the valid characters in the buffers.  */
+  Idx valid_len;
+  /* The corresponding number of bytes in raw_mbs array.  */
+  Idx valid_raw_len;
+  /* The length of the buffers MBS and WCS.  */
+  Idx bufs_len;
+  /* The index in MBS, which is updated by re_string_fetch_byte.  */
+  Idx cur_idx;
+  /* length of RAW_MBS array.  */
+  Idx raw_len;
+  /* This is RAW_LEN - RAW_MBS_IDX + VALID_LEN - VALID_RAW_LEN.  */
+  Idx len;
+  /* End of the buffer may be shorter than its length in the cases such
+     as re_match_2, re_search_2.  Then, we use STOP for end of the buffer
+     instead of LEN.  */
+  Idx raw_stop;
+  /* This is RAW_STOP - RAW_MBS_IDX adjusted through OFFSETS.  */
+  Idx stop;
+
+  /* The context of mbs[0].  We store the context independently, since
+     the context of mbs[0] may be different from raw_mbs[0], which is
+     the beginning of the input string.  */
+  unsigned int tip_context;
+  /* The translation passed as a part of an argument of re_compile_pattern.  */
+  RE_TRANSLATE_TYPE trans;
+  /* Copy of re_dfa_t's word_char.  */
+  re_const_bitset_ptr_t word_char;
+  /* true if REG_ICASE.  */
+  unsigned char icase;
+  unsigned char is_utf8;
+  unsigned char map_notascii;
+  unsigned char mbs_allocated;
+  unsigned char offsets_needed;
+  unsigned char newline_anchor;
+  unsigned char word_ops_used;
+  int mb_cur_max;
+};
+typedef struct re_string_t re_string_t;
+
+
+struct re_dfa_t;
+typedef struct re_dfa_t re_dfa_t;
+
+#ifndef _LIBC
+# define internal_function
+#endif
+
+static reg_errcode_t re_string_realloc_buffers (re_string_t *pstr,
+                                               Idx new_buf_len)
+     internal_function;
+#ifdef RE_ENABLE_I18N
+static void build_wcs_buffer (re_string_t *pstr) internal_function;
+static reg_errcode_t build_wcs_upper_buffer (re_string_t *pstr)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static void build_upper_buffer (re_string_t *pstr) internal_function;
+static void re_string_translate_buffer (re_string_t *pstr) internal_function;
+static unsigned int re_string_context_at (const re_string_t *input, Idx idx,
+                                         int eflags)
+     internal_function __attribute ((pure));
+#define re_string_peek_byte(pstr, offset) \
+  ((pstr)->mbs[(pstr)->cur_idx + offset])
+#define re_string_fetch_byte(pstr) \
+  ((pstr)->mbs[(pstr)->cur_idx++])
+#define re_string_first_byte(pstr, idx) \
+  ((idx) == (pstr)->valid_len || (pstr)->wcs[idx] != WEOF)
+#define re_string_is_single_byte_char(pstr, idx) \
+  ((pstr)->wcs[idx] != WEOF && ((pstr)->valid_len == (idx) + 1 \
+                               || (pstr)->wcs[(idx) + 1] != WEOF))
+#define re_string_eoi(pstr) ((pstr)->stop <= (pstr)->cur_idx)
+#define re_string_cur_idx(pstr) ((pstr)->cur_idx)
+#define re_string_get_buffer(pstr) ((pstr)->mbs)
+#define re_string_length(pstr) ((pstr)->len)
+#define re_string_byte_at(pstr,idx) ((pstr)->mbs[idx])
+#define re_string_skip_bytes(pstr,idx) ((pstr)->cur_idx += (idx))
+#define re_string_set_index(pstr,idx) ((pstr)->cur_idx = (idx))
+
+#include <alloca.h>
+
+#ifndef _LIBC
+# if HAVE_ALLOCA
+/* The OS usually guarantees only one guard page at the bottom of the stack,
+   and a page size can be as small as 4096 bytes.  So we cannot safely
+   allocate anything larger than 4096 bytes.  Also care for the possibility
+   of a few compiler-allocated temporary stack slots.  */
+#  define __libc_use_alloca(n) ((n) < 4032)
+# else
+/* alloca is implemented with malloc, so just use malloc.  */
+#  define __libc_use_alloca(n) 0
+#  undef alloca
+#  define alloca(n) malloc (n)
+# endif
+#endif
+
+#ifndef MAX
+# define MAX(a,b) ((a) < (b) ? (b) : (a))
+#endif
+
+#define re_malloc(t,n) ((t *) malloc ((n) * sizeof (t)))
+#define re_realloc(p,t,n) ((t *) realloc (p, (n) * sizeof (t)))
+#define re_free(p) free (p)
+
+struct bin_tree_t
+{
+  struct bin_tree_t *parent;
+  struct bin_tree_t *left;
+  struct bin_tree_t *right;
+  struct bin_tree_t *first;
+  struct bin_tree_t *next;
+
+  re_token_t token;
+
+  /* 'node_idx' is the index in dfa->nodes, if 'type' == 0.
+     Otherwise 'type' indicate the type of this node.  */
+  Idx node_idx;
+};
+typedef struct bin_tree_t bin_tree_t;
+
+#define BIN_TREE_STORAGE_SIZE \
+  ((1024 - sizeof (void *)) / sizeof (bin_tree_t))
+
+struct bin_tree_storage_t
+{
+  struct bin_tree_storage_t *next;
+  bin_tree_t data[BIN_TREE_STORAGE_SIZE];
+};
+typedef struct bin_tree_storage_t bin_tree_storage_t;
+
+#define CONTEXT_WORD 1
+#define CONTEXT_NEWLINE (CONTEXT_WORD << 1)
+#define CONTEXT_BEGBUF (CONTEXT_NEWLINE << 1)
+#define CONTEXT_ENDBUF (CONTEXT_BEGBUF << 1)
+
+#define IS_WORD_CONTEXT(c) ((c) & CONTEXT_WORD)
+#define IS_NEWLINE_CONTEXT(c) ((c) & CONTEXT_NEWLINE)
+#define IS_BEGBUF_CONTEXT(c) ((c) & CONTEXT_BEGBUF)
+#define IS_ENDBUF_CONTEXT(c) ((c) & CONTEXT_ENDBUF)
+#define IS_ORDINARY_CONTEXT(c) ((c) == 0)
+
+#define IS_WORD_CHAR(ch) (isalnum (ch) || (ch) == '_')
+#define IS_NEWLINE(ch) ((ch) == NEWLINE_CHAR)
+#define IS_WIDE_WORD_CHAR(ch) (iswalnum (ch) || (ch) == L'_')
+#define IS_WIDE_NEWLINE(ch) ((ch) == WIDE_NEWLINE_CHAR)
+
+#define NOT_SATISFY_PREV_CONSTRAINT(constraint,context) \
+ ((((constraint) & PREV_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || ((constraint & PREV_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT (context))\
+  || ((constraint & PREV_BEGBUF_CONSTRAINT) && !IS_BEGBUF_CONTEXT (context)))
+
+#define NOT_SATISFY_NEXT_CONSTRAINT(constraint,context) \
+ ((((constraint) & NEXT_WORD_CONSTRAINT) && !IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NOTWORD_CONSTRAINT) && IS_WORD_CONTEXT (context)) \
+  || (((constraint) & NEXT_NEWLINE_CONSTRAINT) && !IS_NEWLINE_CONTEXT 
(context)) \
+  || (((constraint) & NEXT_ENDBUF_CONSTRAINT) && !IS_ENDBUF_CONTEXT (context)))
+
+struct re_dfastate_t
+{
+  re_hashval_t hash;
+  re_node_set nodes;
+  re_node_set non_eps_nodes;
+  re_node_set inveclosure;
+  re_node_set *entrance_nodes;
+  struct re_dfastate_t **trtable, **word_trtable;
+  unsigned int context : 4;
+  unsigned int halt : 1;
+  /* If this state can accept "multi byte".
+     Note that we refer to multibyte characters, and multi character
+     collating elements as "multi byte".  */
+  unsigned int accept_mb : 1;
+  /* If this state has backreference node(s).  */
+  unsigned int has_backref : 1;
+  unsigned int has_constraint : 1;
+};
+typedef struct re_dfastate_t re_dfastate_t;
+
+struct re_state_table_entry
+{
+  Idx num;
+  Idx alloc;
+  re_dfastate_t **array;
+};
+
+/* Array type used in re_sub_match_last_t and re_sub_match_top_t.  */
+
+typedef struct
+{
+  Idx next_idx;
+  Idx alloc;
+  re_dfastate_t **array;
+} state_array_t;
+
+/* Store information about the node NODE whose type is OP_CLOSE_SUBEXP.  */
+
+typedef struct
+{
+  Idx node;
+  Idx str_idx; /* The position NODE match at.  */
+  state_array_t path;
+} re_sub_match_last_t;
+
+/* Store information about the node NODE whose type is OP_OPEN_SUBEXP.
+   And information about the node, whose type is OP_CLOSE_SUBEXP,
+   corresponding to NODE is stored in LASTS.  */
+
+typedef struct
+{
+  Idx str_idx;
+  Idx node;
+  state_array_t *path;
+  Idx alasts; /* Allocation size of LASTS.  */
+  Idx nlasts; /* The number of LASTS.  */
+  re_sub_match_last_t **lasts;
+} re_sub_match_top_t;
+
+struct re_backref_cache_entry
+{
+  Idx node;
+  Idx str_idx;
+  Idx subexp_from;
+  Idx subexp_to;
+  char more;
+  char unused;
+  unsigned short int eps_reachable_subexps_map;
+};
+
+typedef struct
+{
+  /* The string object corresponding to the input string.  */
+  re_string_t input;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  const re_dfa_t *const dfa;
+#else
+  const re_dfa_t *dfa;
+#endif
+  /* EFLAGS of the argument of regexec.  */
+  int eflags;
+  /* Where the matching ends.  */
+  Idx match_last;
+  Idx last_node;
+  /* The state log used by the matcher.  */
+  re_dfastate_t **state_log;
+  Idx state_log_top;
+  /* Back reference cache.  */
+  Idx nbkref_ents;
+  Idx abkref_ents;
+  struct re_backref_cache_entry *bkref_ents;
+  int max_mb_elem_len;
+  Idx nsub_tops;
+  Idx asub_tops;
+  re_sub_match_top_t **sub_tops;
+} re_match_context_t;
+
+typedef struct
+{
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **limited_states;
+  Idx last_node;
+  Idx last_str_idx;
+  re_node_set limits;
+} re_sift_context_t;
+
+struct re_fail_stack_ent_t
+{
+  Idx idx;
+  Idx node;
+  regmatch_t *regs;
+  re_node_set eps_via_nodes;
+};
+
+struct re_fail_stack_t
+{
+  Idx num;
+  Idx alloc;
+  struct re_fail_stack_ent_t *stack;
+};
+
+struct re_dfa_t
+{
+  re_token_t *nodes;
+  size_t nodes_alloc;
+  size_t nodes_len;
+  Idx *nexts;
+  Idx *org_indices;
+  re_node_set *edests;
+  re_node_set *eclosures;
+  re_node_set *inveclosures;
+  struct re_state_table_entry *state_table;
+  re_dfastate_t *init_state;
+  re_dfastate_t *init_state_word;
+  re_dfastate_t *init_state_nl;
+  re_dfastate_t *init_state_begbuf;
+  bin_tree_t *str_tree;
+  bin_tree_storage_t *str_tree_storage;
+  re_bitset_ptr_t sb_char;
+  int str_tree_storage_idx;
+
+  /* number of subexpressions 're_nsub' is in regex_t.  */
+  re_hashval_t state_hash_mask;
+  Idx init_node;
+  Idx nbackref; /* The number of backreference in this dfa.  */
+
+  /* Bitmap expressing which backreference is used.  */
+  bitset_word_t used_bkref_map;
+  bitset_word_t completed_bkref_map;
+
+  unsigned int has_plural_match : 1;
+  /* If this dfa has "multibyte node", which is a backreference or
+     a node which can accept multibyte character or multi character
+     collating element.  */
+  unsigned int has_mb_node : 1;
+  unsigned int is_utf8 : 1;
+  unsigned int map_notascii : 1;
+  unsigned int word_ops_used : 1;
+  int mb_cur_max;
+  bitset_t word_char;
+  reg_syntax_t syntax;
+  Idx *subexp_map;
+#ifdef DEBUG
+  char* re_str;
+#endif
+#ifdef _LIBC
+  __libc_lock_define (, lock)
+#endif
+};
+
+#define re_node_set_init_empty(set) memset (set, '\0', sizeof (re_node_set))
+#define re_node_set_remove(set,id) \
+  (re_node_set_remove_at (set, re_node_set_contains (set, id) - 1))
+#define re_node_set_empty(p) ((p)->nelem = 0)
+#define re_node_set_free(set) re_free ((set)->elems)
+
+
+typedef enum
+{
+  SB_CHAR,
+  MB_CHAR,
+  EQUIV_CLASS,
+  COLL_SYM,
+  CHAR_CLASS
+} bracket_elem_type;
+
+typedef struct
+{
+  bracket_elem_type type;
+  union
+  {
+    unsigned char ch;
+    unsigned char *name;
+    wchar_t wch;
+  } opr;
+} bracket_elem_t;
+
+
+/* Inline functions for bitset_t operation.  */
+
+static inline void
+bitset_set (bitset_t set, Idx i)
+{
+  set[i / BITSET_WORD_BITS] |= (bitset_word_t) 1 << i % BITSET_WORD_BITS;
+}
+
+static inline void
+bitset_clear (bitset_t set, Idx i)
+{
+  set[i / BITSET_WORD_BITS] &= ~ ((bitset_word_t) 1 << i % BITSET_WORD_BITS);
+}
+
+static inline bool
+bitset_contain (const bitset_t set, Idx i)
+{
+  return (set[i / BITSET_WORD_BITS] >> i % BITSET_WORD_BITS) & 1;
+}
+
+static inline void
+bitset_empty (bitset_t set)
+{
+  memset (set, '\0', sizeof (bitset_t));
+}
+
+static inline void
+bitset_set_all (bitset_t set)
+{
+  memset (set, -1, sizeof (bitset_word_t) * (SBC_MAX / BITSET_WORD_BITS));
+  if (SBC_MAX % BITSET_WORD_BITS != 0)
+    set[BITSET_WORDS - 1] =
+      ((bitset_word_t) 1 << SBC_MAX % BITSET_WORD_BITS) - 1;
+}
+
+static inline void
+bitset_copy (bitset_t dest, const bitset_t src)
+{
+  memcpy (dest, src, sizeof (bitset_t));
+}
+
+static inline void
+bitset_not (bitset_t set)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < SBC_MAX / BITSET_WORD_BITS; ++bitset_i)
+    set[bitset_i] = ~set[bitset_i];
+  if (SBC_MAX % BITSET_WORD_BITS != 0)
+    set[BITSET_WORDS - 1] =
+      ((((bitset_word_t) 1 << SBC_MAX % BITSET_WORD_BITS) - 1)
+       & ~set[BITSET_WORDS - 1]);
+}
+
+static inline void
+bitset_merge (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] |= src[bitset_i];
+}
+
+static inline void
+bitset_mask (bitset_t dest, const bitset_t src)
+{
+  int bitset_i;
+  for (bitset_i = 0; bitset_i < BITSET_WORDS; ++bitset_i)
+    dest[bitset_i] &= src[bitset_i];
+}
+
+#ifdef RE_ENABLE_I18N
+/* Inline functions for re_string.  */
+static inline int
+internal_function __attribute ((pure))
+re_string_char_size_at (const re_string_t *pstr, Idx idx)
+{
+  int byte_idx;
+  if (pstr->mb_cur_max == 1)
+    return 1;
+  for (byte_idx = 1; idx + byte_idx < pstr->valid_len; ++byte_idx)
+    if (pstr->wcs[idx + byte_idx] != WEOF)
+      break;
+  return byte_idx;
+}
+
+static inline wint_t
+internal_function __attribute ((pure))
+re_string_wchar_at (const re_string_t *pstr, Idx idx)
+{
+  if (pstr->mb_cur_max == 1)
+    return (wint_t) pstr->mbs[idx];
+  return (wint_t) pstr->wcs[idx];
+}
+
+static int
+internal_function __attribute ((pure))
+re_string_elem_size_at (const re_string_t *pstr, Idx idx)
+{
+# ifdef _LIBC
+  const unsigned char *p, *extra;
+  const int32_t *table, *indirect;
+  int32_t tmp;
+#  include <locale/weight.h>
+  uint_fast32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+
+  if (nrules != 0)
+    {
+      table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+      extra = (const unsigned char *)
+       _NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+      indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
+                                               _NL_COLLATE_INDIRECTMB);
+      p = pstr->mbs + idx;
+      tmp = findidx (&p);
+      return p - pstr->mbs - idx;
+    }
+  else
+# endif /* _LIBC */
+    return 1;
+}
+#endif /* RE_ENABLE_I18N */
+
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+#  define __GNUC_PREREQ(maj, min) \
+         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+# else
+#  define __GNUC_PREREQ(maj, min) 0
+# endif
+#endif
+
+#if __GNUC_PREREQ (3,4)
+# undef __attribute_warn_unused_result__
+# define __attribute_warn_unused_result__ \
+   __attribute__ ((__warn_unused_result__))
+#else
+# define __attribute_warn_unused_result__ /* empty */
+#endif
+
+#endif /*  _REGEX_INTERNAL_H */
diff --git a/lib/regexec.c b/lib/regexec.c
new file mode 100644
index 0000000..7130f2a
--- /dev/null
+++ b/lib/regexec.c
@@ -0,0 +1,4417 @@
+/* Extended regular expression matching and search library.
+   Copyright (C) 2002-2012 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Isamu Hasegawa <address@hidden>.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License 
along
+   with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+static reg_errcode_t match_ctx_init (re_match_context_t *cache, int eflags,
+                                    Idx n) internal_function;
+static void match_ctx_clean (re_match_context_t *mctx) internal_function;
+static void match_ctx_free (re_match_context_t *cache) internal_function;
+static reg_errcode_t match_ctx_add_entry (re_match_context_t *cache, Idx node,
+                                         Idx str_idx, Idx from, Idx to)
+     internal_function;
+static Idx search_cur_bkref_entry (const re_match_context_t *mctx, Idx str_idx)
+     internal_function;
+static reg_errcode_t match_ctx_add_subtop (re_match_context_t *mctx, Idx node,
+                                          Idx str_idx) internal_function;
+static re_sub_match_last_t * match_ctx_add_sublast (re_sub_match_top_t *subtop,
+                                                   Idx node, Idx str_idx)
+     internal_function;
+static void sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+                          re_dfastate_t **limited_sts, Idx last_node,
+                          Idx last_str_idx)
+     internal_function;
+static reg_errcode_t re_search_internal (const regex_t *preg,
+                                        const char *string, Idx length,
+                                        Idx start, Idx last_start, Idx stop,
+                                        size_t nmatch, regmatch_t pmatch[],
+                                        int eflags) internal_function;
+static regoff_t re_search_2_stub (struct re_pattern_buffer *bufp,
+                                 const char *string1, Idx length1,
+                                 const char *string2, Idx length2,
+                                 Idx start, regoff_t range,
+                                 struct re_registers *regs,
+                                 Idx stop, bool ret_len) internal_function;
+static regoff_t re_search_stub (struct re_pattern_buffer *bufp,
+                               const char *string, Idx length, Idx start,
+                               regoff_t range, Idx stop,
+                               struct re_registers *regs,
+                               bool ret_len) internal_function;
+static unsigned int re_copy_regs (struct re_registers *regs, regmatch_t 
*pmatch,
+                                 Idx nregs, int regs_allocated)
+     internal_function;
+static reg_errcode_t prune_impossible_nodes (re_match_context_t *mctx)
+     internal_function;
+static Idx check_matching (re_match_context_t *mctx, bool fl_longest_match,
+                          Idx *p_match_first) internal_function;
+static Idx check_halt_state_context (const re_match_context_t *mctx,
+                                    const re_dfastate_t *state, Idx idx)
+     internal_function;
+static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+                        regmatch_t *prev_idx_match, Idx cur_node,
+                        Idx cur_idx, Idx nmatch) internal_function;
+static reg_errcode_t push_fail_stack (struct re_fail_stack_t *fs,
+                                     Idx str_idx, Idx dest_node, Idx nregs,
+                                     regmatch_t *regs,
+                                     re_node_set *eps_via_nodes)
+     internal_function;
+static reg_errcode_t set_regs (const regex_t *preg,
+                              const re_match_context_t *mctx,
+                              size_t nmatch, regmatch_t *pmatch,
+                              bool fl_backtrack) internal_function;
+static reg_errcode_t free_fail_stack_return (struct re_fail_stack_t *fs)
+     internal_function;
+
+#ifdef RE_ENABLE_I18N
+static int sift_states_iter_mb (const re_match_context_t *mctx,
+                               re_sift_context_t *sctx,
+                               Idx node_idx, Idx str_idx, Idx max_str_idx)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t sift_states_backward (const re_match_context_t *mctx,
+                                          re_sift_context_t *sctx)
+     internal_function;
+static reg_errcode_t build_sifted_states (const re_match_context_t *mctx,
+                                         re_sift_context_t *sctx, Idx str_idx,
+                                         re_node_set *cur_dest)
+     internal_function;
+static reg_errcode_t update_cur_sifted_state (const re_match_context_t *mctx,
+                                             re_sift_context_t *sctx,
+                                             Idx str_idx,
+                                             re_node_set *dest_nodes)
+     internal_function;
+static reg_errcode_t add_epsilon_src_nodes (const re_dfa_t *dfa,
+                                           re_node_set *dest_nodes,
+                                           const re_node_set *candidates)
+     internal_function;
+static bool check_dst_limits (const re_match_context_t *mctx,
+                             const re_node_set *limits,
+                             Idx dst_node, Idx dst_idx, Idx src_node,
+                             Idx src_idx) internal_function;
+static int check_dst_limits_calc_pos_1 (const re_match_context_t *mctx,
+                                       int boundaries, Idx subexp_idx,
+                                       Idx from_node, Idx bkref_idx)
+     internal_function;
+static int check_dst_limits_calc_pos (const re_match_context_t *mctx,
+                                     Idx limit, Idx subexp_idx,
+                                     Idx node, Idx str_idx,
+                                     Idx bkref_idx) internal_function;
+static reg_errcode_t check_subexp_limits (const re_dfa_t *dfa,
+                                         re_node_set *dest_nodes,
+                                         const re_node_set *candidates,
+                                         re_node_set *limits,
+                                         struct re_backref_cache_entry 
*bkref_ents,
+                                         Idx str_idx) internal_function;
+static reg_errcode_t sift_states_bkref (const re_match_context_t *mctx,
+                                       re_sift_context_t *sctx,
+                                       Idx str_idx, const re_node_set 
*candidates)
+     internal_function;
+static reg_errcode_t merge_state_array (const re_dfa_t *dfa,
+                                       re_dfastate_t **dst,
+                                       re_dfastate_t **src, Idx num)
+     internal_function;
+static re_dfastate_t *find_recover_state (reg_errcode_t *err,
+                                        re_match_context_t *mctx) 
internal_function;
+static re_dfastate_t *transit_state (reg_errcode_t *err,
+                                    re_match_context_t *mctx,
+                                    re_dfastate_t *state) internal_function;
+static re_dfastate_t *merge_state_with_log (reg_errcode_t *err,
+                                           re_match_context_t *mctx,
+                                           re_dfastate_t *next_state)
+     internal_function;
+static reg_errcode_t check_subexp_matching_top (re_match_context_t *mctx,
+                                               re_node_set *cur_nodes,
+                                               Idx str_idx) internal_function;
+#if 0
+static re_dfastate_t *transit_state_sb (reg_errcode_t *err,
+                                       re_match_context_t *mctx,
+                                       re_dfastate_t *pstate)
+     internal_function;
+#endif
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t transit_state_mb (re_match_context_t *mctx,
+                                      re_dfastate_t *pstate)
+     internal_function;
+#endif /* RE_ENABLE_I18N */
+static reg_errcode_t transit_state_bkref (re_match_context_t *mctx,
+                                         const re_node_set *nodes)
+     internal_function;
+static reg_errcode_t get_subexp (re_match_context_t *mctx,
+                                Idx bkref_node, Idx bkref_str_idx)
+     internal_function;
+static reg_errcode_t get_subexp_sub (re_match_context_t *mctx,
+                                    const re_sub_match_top_t *sub_top,
+                                    re_sub_match_last_t *sub_last,
+                                    Idx bkref_node, Idx bkref_str)
+     internal_function;
+static Idx find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+                            Idx subexp_idx, int type) internal_function;
+static reg_errcode_t check_arrival (re_match_context_t *mctx,
+                                   state_array_t *path, Idx top_node,
+                                   Idx top_str, Idx last_node, Idx last_str,
+                                   int type) internal_function;
+static reg_errcode_t check_arrival_add_next_nodes (re_match_context_t *mctx,
+                                                  Idx str_idx,
+                                                  re_node_set *cur_nodes,
+                                                  re_node_set *next_nodes)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl (const re_dfa_t *dfa,
+                                              re_node_set *cur_nodes,
+                                              Idx ex_subexp, int type)
+     internal_function;
+static reg_errcode_t check_arrival_expand_ecl_sub (const re_dfa_t *dfa,
+                                                  re_node_set *dst_nodes,
+                                                  Idx target, Idx ex_subexp,
+                                                  int type) internal_function;
+static reg_errcode_t expand_bkref_cache (re_match_context_t *mctx,
+                                        re_node_set *cur_nodes, Idx cur_str,
+                                        Idx subexp_num, int type)
+     internal_function;
+static bool build_trtable (const re_dfa_t *dfa,
+                          re_dfastate_t *state) internal_function;
+#ifdef RE_ENABLE_I18N
+static int check_node_accept_bytes (const re_dfa_t *dfa, Idx node_idx,
+                                   const re_string_t *input, Idx idx)
+     internal_function;
+# ifdef _LIBC
+static unsigned int find_collation_sequence_value (const unsigned char *mbs,
+                                                  size_t name_len)
+     internal_function;
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+static Idx group_nodes_into_DFAstates (const re_dfa_t *dfa,
+                                      const re_dfastate_t *state,
+                                      re_node_set *states_node,
+                                      bitset_t *states_ch) internal_function;
+static bool check_node_accept (const re_match_context_t *mctx,
+                              const re_token_t *node, Idx idx)
+     internal_function;
+static reg_errcode_t extend_buffers (re_match_context_t *mctx)
+     internal_function;
+
+/* Entry point for POSIX code.  */
+
+/* regexec searches for a given pattern, specified by PREG, in the
+   string STRING.
+
+   If NMATCH is zero or REG_NOSUB was set in the cflags argument to
+   'regcomp', we ignore PMATCH.  Otherwise, we assume PMATCH has at
+   least NMATCH elements, and we set them to the offsets of the
+   corresponding matched substrings.
+
+   EFLAGS specifies "execution flags" which affect matching: if
+   REG_NOTBOL is set, then ^ does not match at the beginning of the
+   string; if REG_NOTEOL is set, then $ does not match at the end.
+
+   We return 0 if we find a match and REG_NOMATCH if not.  */
+
+int
+regexec (preg, string, nmatch, pmatch, eflags)
+    const regex_t *_Restrict_ preg;
+    const char *_Restrict_ string;
+    size_t nmatch;
+    regmatch_t pmatch[_Restrict_arr_];
+    int eflags;
+{
+  reg_errcode_t err;
+  Idx start, length;
+#ifdef _LIBC
+  re_dfa_t *dfa = (re_dfa_t *) preg->buffer;
+#endif
+
+  if (eflags & ~(REG_NOTBOL | REG_NOTEOL | REG_STARTEND))
+    return REG_BADPAT;
+
+  if (eflags & REG_STARTEND)
+    {
+      start = pmatch[0].rm_so;
+      length = pmatch[0].rm_eo;
+    }
+  else
+    {
+      start = 0;
+      length = strlen (string);
+    }
+
+  __libc_lock_lock (dfa->lock);
+  if (preg->no_sub)
+    err = re_search_internal (preg, string, length, start, length,
+                             length, 0, NULL, eflags);
+  else
+    err = re_search_internal (preg, string, length, start, length,
+                             length, nmatch, pmatch, eflags);
+  __libc_lock_unlock (dfa->lock);
+  return err != REG_NOERROR;
+}
+
+#ifdef _LIBC
+# include <shlib-compat.h>
+versioned_symbol (libc, __regexec, regexec, GLIBC_2_3_4);
+
+# if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4)
+__typeof__ (__regexec) __compat_regexec;
+
+int
+attribute_compat_text_section
+__compat_regexec (const regex_t *_Restrict_ preg,
+                 const char *_Restrict_ string, size_t nmatch,
+                 regmatch_t pmatch[], int eflags)
+{
+  return regexec (preg, string, nmatch, pmatch,
+                 eflags & (REG_NOTBOL | REG_NOTEOL));
+}
+compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0);
+# endif
+#endif
+
+/* Entry points for GNU code.  */
+
+/* re_match, re_search, re_match_2, re_search_2
+
+   The former two functions operate on STRING with length LENGTH,
+   while the later two operate on concatenation of STRING1 and STRING2
+   with lengths LENGTH1 and LENGTH2, respectively.
+
+   re_match() matches the compiled pattern in BUFP against the string,
+   starting at index START.
+
+   re_search() first tries matching at index START, then it tries to match
+   starting from index START + 1, and so on.  The last start position tried
+   is START + RANGE.  (Thus RANGE = 0 forces re_search to operate the same
+   way as re_match().)
+
+   The parameter STOP of re_{match,search}_2 specifies that no match exceeding
+   the first STOP characters of the concatenation of the strings should be
+   concerned.
+
+   If REGS is not NULL, and BUFP->no_sub is not set, the offsets of the match
+   and all groups is stored in REGS.  (For the "_2" variants, the offsets are
+   computed relative to the concatenation, not relative to the individual
+   strings.)
+
+   On success, re_match* functions return the length of the match, re_search*
+   return the position of the start of the match.  Return value -1 means no
+   match was found and -2 indicates an internal error.  */
+
+regoff_t
+re_match (bufp, string, length, start, regs)
+    struct re_pattern_buffer *bufp;
+    const char *string;
+    Idx length, start;
+    struct re_registers *regs;
+{
+  return re_search_stub (bufp, string, length, start, 0, length, regs, true);
+}
+#ifdef _LIBC
+weak_alias (__re_match, re_match)
+#endif
+
+regoff_t
+re_search (bufp, string, length, start, range, regs)
+    struct re_pattern_buffer *bufp;
+    const char *string;
+    Idx length, start;
+    regoff_t range;
+    struct re_registers *regs;
+{
+  return re_search_stub (bufp, string, length, start, range, length, regs,
+                        false);
+}
+#ifdef _LIBC
+weak_alias (__re_search, re_search)
+#endif
+
+regoff_t
+re_match_2 (bufp, string1, length1, string2, length2, start, regs, stop)
+    struct re_pattern_buffer *bufp;
+    const char *string1, *string2;
+    Idx length1, length2, start, stop;
+    struct re_registers *regs;
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+                          start, 0, regs, stop, true);
+}
+#ifdef _LIBC
+weak_alias (__re_match_2, re_match_2)
+#endif
+
+regoff_t
+re_search_2 (bufp, string1, length1, string2, length2, start, range, regs, 
stop)
+    struct re_pattern_buffer *bufp;
+    const char *string1, *string2;
+    Idx length1, length2, start, stop;
+    regoff_t range;
+    struct re_registers *regs;
+{
+  return re_search_2_stub (bufp, string1, length1, string2, length2,
+                          start, range, regs, stop, false);
+}
+#ifdef _LIBC
+weak_alias (__re_search_2, re_search_2)
+#endif
+
+static regoff_t
+internal_function
+re_search_2_stub (struct re_pattern_buffer *bufp,
+                 const char *string1, Idx length1,
+                 const char *string2, Idx length2,
+                 Idx start, regoff_t range, struct re_registers *regs,
+                 Idx stop, bool ret_len)
+{
+  const char *str;
+  regoff_t rval;
+  Idx len = length1 + length2;
+  char *s = NULL;
+
+  if (BE (length1 < 0 || length2 < 0 || stop < 0 || len < length1, 0))
+    return -2;
+
+  /* Concatenate the strings.  */
+  if (length2 > 0)
+    if (length1 > 0)
+      {
+       s = re_malloc (char, len);
+
+       if (BE (s == NULL, 0))
+         return -2;
+#ifdef _LIBC
+       memcpy (__mempcpy (s, string1, length1), string2, length2);
+#else
+       memcpy (s, string1, length1);
+       memcpy (s + length1, string2, length2);
+#endif
+       str = s;
+      }
+    else
+      str = string2;
+  else
+    str = string1;
+
+  rval = re_search_stub (bufp, str, len, start, range, stop, regs,
+                        ret_len);
+  re_free (s);
+  return rval;
+}
+
+/* The parameters have the same meaning as those of re_search.
+   Additional parameters:
+   If RET_LEN is true the length of the match is returned (re_match style);
+   otherwise the position of the match is returned.  */
+
+static regoff_t
+internal_function
+re_search_stub (struct re_pattern_buffer *bufp,
+               const char *string, Idx length,
+               Idx start, regoff_t range, Idx stop, struct re_registers *regs,
+               bool ret_len)
+{
+  reg_errcode_t result;
+  regmatch_t *pmatch;
+  Idx nregs;
+  regoff_t rval;
+  int eflags = 0;
+#ifdef _LIBC
+  re_dfa_t *dfa = (re_dfa_t *) bufp->buffer;
+#endif
+  Idx last_start = start + range;
+
+  /* Check for out-of-range.  */
+  if (BE (start < 0 || start > length, 0))
+    return -1;
+  if (BE (length < last_start || (0 <= range && last_start < start), 0))
+    last_start = length;
+  else if (BE (last_start < 0 || (range < 0 && start <= last_start), 0))
+    last_start = 0;
+
+  __libc_lock_lock (dfa->lock);
+
+  eflags |= (bufp->not_bol) ? REG_NOTBOL : 0;
+  eflags |= (bufp->not_eol) ? REG_NOTEOL : 0;
+
+  /* Compile fastmap if we haven't yet.  */
+  if (start < last_start && bufp->fastmap != NULL && !bufp->fastmap_accurate)
+    re_compile_fastmap (bufp);
+
+  if (BE (bufp->no_sub, 0))
+    regs = NULL;
+
+  /* We need at least 1 register.  */
+  if (regs == NULL)
+    nregs = 1;
+  else if (BE (bufp->regs_allocated == REGS_FIXED
+              && regs->num_regs <= bufp->re_nsub, 0))
+    {
+      nregs = regs->num_regs;
+      if (BE (nregs < 1, 0))
+       {
+         /* Nothing can be copied to regs.  */
+         regs = NULL;
+         nregs = 1;
+       }
+    }
+  else
+    nregs = bufp->re_nsub + 1;
+  pmatch = re_malloc (regmatch_t, nregs);
+  if (BE (pmatch == NULL, 0))
+    {
+      rval = -2;
+      goto out;
+    }
+
+  result = re_search_internal (bufp, string, length, start, last_start, stop,
+                              nregs, pmatch, eflags);
+
+  rval = 0;
+
+  /* I hope we needn't fill ther regs with -1's when no match was found.  */
+  if (result != REG_NOERROR)
+    rval = -1;
+  else if (regs != NULL)
+    {
+      /* If caller wants register contents data back, copy them.  */
+      bufp->regs_allocated = re_copy_regs (regs, pmatch, nregs,
+                                          bufp->regs_allocated);
+      if (BE (bufp->regs_allocated == REGS_UNALLOCATED, 0))
+       rval = -2;
+    }
+
+  if (BE (rval == 0, 1))
+    {
+      if (ret_len)
+       {
+         assert (pmatch[0].rm_so == start);
+         rval = pmatch[0].rm_eo - start;
+       }
+      else
+       rval = pmatch[0].rm_so;
+    }
+  re_free (pmatch);
+ out:
+  __libc_lock_unlock (dfa->lock);
+  return rval;
+}
+
+static unsigned int
+internal_function
+re_copy_regs (struct re_registers *regs, regmatch_t *pmatch, Idx nregs,
+             int regs_allocated)
+{
+  int rval = REGS_REALLOCATE;
+  Idx i;
+  Idx need_regs = nregs + 1;
+  /* We need one extra element beyond 'num_regs' for the '-1' marker GNU code
+     uses.  */
+
+  /* Have the register data arrays been allocated?  */
+  if (regs_allocated == REGS_UNALLOCATED)
+    { /* No.  So allocate them with malloc.  */
+      regs->start = re_malloc (regoff_t, need_regs);
+      if (BE (regs->start == NULL, 0))
+       return REGS_UNALLOCATED;
+      regs->end = re_malloc (regoff_t, need_regs);
+      if (BE (regs->end == NULL, 0))
+       {
+         re_free (regs->start);
+         return REGS_UNALLOCATED;
+       }
+      regs->num_regs = need_regs;
+    }
+  else if (regs_allocated == REGS_REALLOCATE)
+    { /* Yes.  If we need more elements than were already
+        allocated, reallocate them.  If we need fewer, just
+        leave it alone.  */
+      if (BE (need_regs > regs->num_regs, 0))
+       {
+         regoff_t *new_start = re_realloc (regs->start, regoff_t, need_regs);
+         regoff_t *new_end;
+         if (BE (new_start == NULL, 0))
+           return REGS_UNALLOCATED;
+         new_end = re_realloc (regs->end, regoff_t, need_regs);
+         if (BE (new_end == NULL, 0))
+           {
+             re_free (new_start);
+             return REGS_UNALLOCATED;
+           }
+         regs->start = new_start;
+         regs->end = new_end;
+         regs->num_regs = need_regs;
+       }
+    }
+  else
+    {
+      assert (regs_allocated == REGS_FIXED);
+      /* This function may not be called with REGS_FIXED and nregs too big.  */
+      assert (regs->num_regs >= nregs);
+      rval = REGS_FIXED;
+    }
+
+  /* Copy the regs.  */
+  for (i = 0; i < nregs; ++i)
+    {
+      regs->start[i] = pmatch[i].rm_so;
+      regs->end[i] = pmatch[i].rm_eo;
+    }
+  for ( ; i < regs->num_regs; ++i)
+    regs->start[i] = regs->end[i] = -1;
+
+  return rval;
+}
+
+/* Set REGS to hold NUM_REGS registers, storing them in STARTS and
+   ENDS.  Subsequent matches using PATTERN_BUFFER and REGS will use
+   this memory for recording register information.  STARTS and ENDS
+   must be allocated using the malloc library routine, and must each
+   be at least NUM_REGS * sizeof (regoff_t) bytes long.
+
+   If NUM_REGS == 0, then subsequent matches should allocate their own
+   register data.
+
+   Unless this function is called, the first search or match using
+   PATTERN_BUFFER will allocate its own register data, without
+   freeing the old data.  */
+
+void
+re_set_registers (bufp, regs, num_regs, starts, ends)
+    struct re_pattern_buffer *bufp;
+    struct re_registers *regs;
+    __re_size_t num_regs;
+    regoff_t *starts, *ends;
+{
+  if (num_regs)
+    {
+      bufp->regs_allocated = REGS_REALLOCATE;
+      regs->num_regs = num_regs;
+      regs->start = starts;
+      regs->end = ends;
+    }
+  else
+    {
+      bufp->regs_allocated = REGS_UNALLOCATED;
+      regs->num_regs = 0;
+      regs->start = regs->end = NULL;
+    }
+}
+#ifdef _LIBC
+weak_alias (__re_set_registers, re_set_registers)
+#endif
+
+/* Entry points compatible with 4.2 BSD regex library.  We don't define
+   them unless specifically requested.  */
+
+#if defined _REGEX_RE_COMP || defined _LIBC
+int
+# ifdef _LIBC
+weak_function
+# endif
+re_exec (s)
+     const char *s;
+{
+  return 0 == regexec (&re_comp_buf, s, 0, NULL, 0);
+}
+#endif /* _REGEX_RE_COMP */
+
+/* Internal entry point.  */
+
+/* Searches for a compiled pattern PREG in the string STRING, whose
+   length is LENGTH.  NMATCH, PMATCH, and EFLAGS have the same
+   meaning as with regexec.  LAST_START is START + RANGE, where
+   START and RANGE have the same meaning as with re_search.
+   Return REG_NOERROR if we find a match, and REG_NOMATCH if not,
+   otherwise return the error code.
+   Note: We assume front end functions already check ranges.
+   (0 <= LAST_START && LAST_START <= LENGTH)  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+re_search_internal (const regex_t *preg,
+                   const char *string, Idx length,
+                   Idx start, Idx last_start, Idx stop,
+                   size_t nmatch, regmatch_t pmatch[],
+                   int eflags)
+{
+  reg_errcode_t err;
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  Idx left_lim, right_lim;
+  int incr;
+  bool fl_longest_match;
+  int match_kind;
+  Idx match_first;
+  Idx match_last = REG_MISSING;
+  Idx extra_nmatch;
+  bool sb;
+  int ch;
+#if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)
+  re_match_context_t mctx = { .dfa = dfa };
+#else
+  re_match_context_t mctx;
+#endif
+  char *fastmap = ((preg->fastmap != NULL && preg->fastmap_accurate
+                   && start != last_start && !preg->can_be_null)
+                  ? preg->fastmap : NULL);
+  RE_TRANSLATE_TYPE t = preg->translate;
+
+#if !(defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 
199901L))
+  memset (&mctx, '\0', sizeof (re_match_context_t));
+  mctx.dfa = dfa;
+#endif
+
+  extra_nmatch = (nmatch > preg->re_nsub) ? nmatch - (preg->re_nsub + 1) : 0;
+  nmatch -= extra_nmatch;
+
+  /* Check if the DFA haven't been compiled.  */
+  if (BE (preg->used == 0 || dfa->init_state == NULL
+         || dfa->init_state_word == NULL || dfa->init_state_nl == NULL
+         || dfa->init_state_begbuf == NULL, 0))
+    return REG_NOMATCH;
+
+#ifdef DEBUG
+  /* We assume front-end functions already check them.  */
+  assert (0 <= last_start && last_start <= length);
+#endif
+
+  /* If initial states with non-begbuf contexts have no elements,
+     the regex must be anchored.  If preg->newline_anchor is set,
+     we'll never use init_state_nl, so do not check it.  */
+  if (dfa->init_state->nodes.nelem == 0
+      && dfa->init_state_word->nodes.nelem == 0
+      && (dfa->init_state_nl->nodes.nelem == 0
+         || !preg->newline_anchor))
+    {
+      if (start != 0 && last_start != 0)
+        return REG_NOMATCH;
+      start = last_start = 0;
+    }
+
+  /* We must check the longest matching, if nmatch > 0.  */
+  fl_longest_match = (nmatch != 0 || dfa->nbackref);
+
+  err = re_string_allocate (&mctx.input, string, length, dfa->nodes_len + 1,
+                           preg->translate, (preg->syntax & RE_ICASE) != 0,
+                           dfa);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+  mctx.input.stop = stop;
+  mctx.input.raw_stop = stop;
+  mctx.input.newline_anchor = preg->newline_anchor;
+
+  err = match_ctx_init (&mctx, eflags, dfa->nbackref * 2);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* We will log all the DFA states through which the dfa pass,
+     if nmatch > 1, or this dfa has "multibyte node", which is a
+     back-reference or a node which can accept multibyte character or
+     multi character collating element.  */
+  if (nmatch > 1 || dfa->has_mb_node)
+    {
+      /* Avoid overflow.  */
+      if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= mctx.input.bufs_len, 0))
+       {
+         err = REG_ESPACE;
+         goto free_return;
+       }
+
+      mctx.state_log = re_malloc (re_dfastate_t *, mctx.input.bufs_len + 1);
+      if (BE (mctx.state_log == NULL, 0))
+       {
+         err = REG_ESPACE;
+         goto free_return;
+       }
+    }
+  else
+    mctx.state_log = NULL;
+
+  match_first = start;
+  mctx.input.tip_context = (eflags & REG_NOTBOL) ? CONTEXT_BEGBUF
+                          : CONTEXT_NEWLINE | CONTEXT_BEGBUF;
+
+  /* Check incrementally whether of not the input string match.  */
+  incr = (last_start < start) ? -1 : 1;
+  left_lim = (last_start < start) ? last_start : start;
+  right_lim = (last_start < start) ? start : last_start;
+  sb = dfa->mb_cur_max == 1;
+  match_kind =
+    (fastmap
+     ? ((sb || !(preg->syntax & RE_ICASE || t) ? 4 : 0)
+       | (start <= last_start ? 2 : 0)
+       | (t != NULL ? 1 : 0))
+     : 8);
+
+  for (;; match_first += incr)
+    {
+      err = REG_NOMATCH;
+      if (match_first < left_lim || right_lim < match_first)
+       goto free_return;
+
+      /* Advance as rapidly as possible through the string, until we
+        find a plausible place to start matching.  This may be done
+        with varying efficiency, so there are various possibilities:
+        only the most common of them are specialized, in order to
+        save on code size.  We use a switch statement for speed.  */
+      switch (match_kind)
+       {
+       case 8:
+         /* No fastmap.  */
+         break;
+
+       case 7:
+         /* Fastmap with single-byte translation, match forward.  */
+         while (BE (match_first < right_lim, 1)
+                && !fastmap[t[(unsigned char) string[match_first]]])
+           ++match_first;
+         goto forward_match_found_start_or_reached_end;
+
+       case 6:
+         /* Fastmap without translation, match forward.  */
+         while (BE (match_first < right_lim, 1)
+                && !fastmap[(unsigned char) string[match_first]])
+           ++match_first;
+
+       forward_match_found_start_or_reached_end:
+         if (BE (match_first == right_lim, 0))
+           {
+             ch = match_first >= length
+                      ? 0 : (unsigned char) string[match_first];
+             if (!fastmap[t ? t[ch] : ch])
+               goto free_return;
+           }
+         break;
+
+       case 4:
+       case 5:
+         /* Fastmap without multi-byte translation, match backwards.  */
+         while (match_first >= left_lim)
+           {
+             ch = match_first >= length
+                      ? 0 : (unsigned char) string[match_first];
+             if (fastmap[t ? t[ch] : ch])
+               break;
+             --match_first;
+           }
+         if (match_first < left_lim)
+           goto free_return;
+         break;
+
+       default:
+         /* In this case, we can't determine easily the current byte,
+            since it might be a component byte of a multibyte
+            character.  Then we use the constructed buffer instead.  */
+         for (;;)
+           {
+             /* If MATCH_FIRST is out of the valid range, reconstruct the
+                buffers.  */
+             __re_size_t offset = match_first - mctx.input.raw_mbs_idx;
+             if (BE (offset >= (__re_size_t) mctx.input.valid_raw_len, 0))
+               {
+                 err = re_string_reconstruct (&mctx.input, match_first,
+                                              eflags);
+                 if (BE (err != REG_NOERROR, 0))
+                   goto free_return;
+
+                 offset = match_first - mctx.input.raw_mbs_idx;
+               }
+             /* If MATCH_FIRST is out of the buffer, leave it as '\0'.
+                Note that MATCH_FIRST must not be smaller than 0.  */
+             ch = (match_first >= length
+                   ? 0 : re_string_byte_at (&mctx.input, offset));
+             if (fastmap[ch])
+               break;
+             match_first += incr;
+             if (match_first < left_lim || match_first > right_lim)
+               {
+                 err = REG_NOMATCH;
+                 goto free_return;
+               }
+           }
+         break;
+       }
+
+      /* Reconstruct the buffers so that the matcher can assume that
+        the matching starts from the beginning of the buffer.  */
+      err = re_string_reconstruct (&mctx.input, match_first, eflags);
+      if (BE (err != REG_NOERROR, 0))
+       goto free_return;
+
+#ifdef RE_ENABLE_I18N
+     /* Don't consider this char as a possible match start if it part,
+       yet isn't the head, of a multibyte character.  */
+      if (!sb && !re_string_first_byte (&mctx.input, 0))
+       continue;
+#endif
+
+      /* It seems to be appropriate one, then use the matcher.  */
+      /* We assume that the matching starts from 0.  */
+      mctx.state_log_top = mctx.nbkref_ents = mctx.max_mb_elem_len = 0;
+      match_last = check_matching (&mctx, fl_longest_match,
+                                  start <= last_start ? &match_first : NULL);
+      if (match_last != REG_MISSING)
+       {
+         if (BE (match_last == REG_ERROR, 0))
+           {
+             err = REG_ESPACE;
+             goto free_return;
+           }
+         else
+           {
+             mctx.match_last = match_last;
+             if ((!preg->no_sub && nmatch > 1) || dfa->nbackref)
+               {
+                 re_dfastate_t *pstate = mctx.state_log[match_last];
+                 mctx.last_node = check_halt_state_context (&mctx, pstate,
+                                                            match_last);
+               }
+             if ((!preg->no_sub && nmatch > 1 && dfa->has_plural_match)
+                 || dfa->nbackref)
+               {
+                 err = prune_impossible_nodes (&mctx);
+                 if (err == REG_NOERROR)
+                   break;
+                 if (BE (err != REG_NOMATCH, 0))
+                   goto free_return;
+                 match_last = REG_MISSING;
+               }
+             else
+               break; /* We found a match.  */
+           }
+       }
+
+      match_ctx_clean (&mctx);
+    }
+
+#ifdef DEBUG
+  assert (match_last != REG_MISSING);
+  assert (err == REG_NOERROR);
+#endif
+
+  /* Set pmatch[] if we need.  */
+  if (nmatch > 0)
+    {
+      Idx reg_idx;
+
+      /* Initialize registers.  */
+      for (reg_idx = 1; reg_idx < nmatch; ++reg_idx)
+       pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1;
+
+      /* Set the points where matching start/end.  */
+      pmatch[0].rm_so = 0;
+      pmatch[0].rm_eo = mctx.match_last;
+      /* FIXME: This function should fail if mctx.match_last exceeds
+        the maximum possible regoff_t value.  We need a new error
+        code REG_OVERFLOW.  */
+
+      if (!preg->no_sub && nmatch > 1)
+       {
+         err = set_regs (preg, &mctx, nmatch, pmatch,
+                         dfa->has_plural_match && dfa->nbackref > 0);
+         if (BE (err != REG_NOERROR, 0))
+           goto free_return;
+       }
+
+      /* At last, add the offset to the each registers, since we slided
+        the buffers so that we could assume that the matching starts
+        from 0.  */
+      for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+       if (pmatch[reg_idx].rm_so != -1)
+         {
+#ifdef RE_ENABLE_I18N
+           if (BE (mctx.input.offsets_needed != 0, 0))
+             {
+               pmatch[reg_idx].rm_so =
+                 (pmatch[reg_idx].rm_so == mctx.input.valid_len
+                  ? mctx.input.valid_raw_len
+                  : mctx.input.offsets[pmatch[reg_idx].rm_so]);
+               pmatch[reg_idx].rm_eo =
+                 (pmatch[reg_idx].rm_eo == mctx.input.valid_len
+                  ? mctx.input.valid_raw_len
+                  : mctx.input.offsets[pmatch[reg_idx].rm_eo]);
+             }
+#else
+           assert (mctx.input.offsets_needed == 0);
+#endif
+           pmatch[reg_idx].rm_so += match_first;
+           pmatch[reg_idx].rm_eo += match_first;
+         }
+      for (reg_idx = 0; reg_idx < extra_nmatch; ++reg_idx)
+       {
+         pmatch[nmatch + reg_idx].rm_so = -1;
+         pmatch[nmatch + reg_idx].rm_eo = -1;
+       }
+
+      if (dfa->subexp_map)
+       for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++)
+         if (dfa->subexp_map[reg_idx] != reg_idx)
+           {
+             pmatch[reg_idx + 1].rm_so
+               = pmatch[dfa->subexp_map[reg_idx] + 1].rm_so;
+             pmatch[reg_idx + 1].rm_eo
+               = pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo;
+           }
+    }
+
+ free_return:
+  re_free (mctx.state_log);
+  if (dfa->nbackref)
+    match_ctx_free (&mctx);
+  re_string_destruct (&mctx.input);
+  return err;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+prune_impossible_nodes (re_match_context_t *mctx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx halt_node, match_last;
+  reg_errcode_t ret;
+  re_dfastate_t **sifted_states;
+  re_dfastate_t **lim_states = NULL;
+  re_sift_context_t sctx;
+#ifdef DEBUG
+  assert (mctx->state_log != NULL);
+#endif
+  match_last = mctx->match_last;
+  halt_node = mctx->last_node;
+
+  /* Avoid overflow.  */
+  if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= match_last, 0))
+    return REG_ESPACE;
+
+  sifted_states = re_malloc (re_dfastate_t *, match_last + 1);
+  if (BE (sifted_states == NULL, 0))
+    {
+      ret = REG_ESPACE;
+      goto free_return;
+    }
+  if (dfa->nbackref)
+    {
+      lim_states = re_malloc (re_dfastate_t *, match_last + 1);
+      if (BE (lim_states == NULL, 0))
+       {
+         ret = REG_ESPACE;
+         goto free_return;
+       }
+      while (1)
+       {
+         memset (lim_states, '\0',
+                 sizeof (re_dfastate_t *) * (match_last + 1));
+         sift_ctx_init (&sctx, sifted_states, lim_states, halt_node,
+                        match_last);
+         ret = sift_states_backward (mctx, &sctx);
+         re_node_set_free (&sctx.limits);
+         if (BE (ret != REG_NOERROR, 0))
+             goto free_return;
+         if (sifted_states[0] != NULL || lim_states[0] != NULL)
+           break;
+         do
+           {
+             --match_last;
+             if (! REG_VALID_INDEX (match_last))
+               {
+                 ret = REG_NOMATCH;
+                 goto free_return;
+               }
+           } while (mctx->state_log[match_last] == NULL
+                    || !mctx->state_log[match_last]->halt);
+         halt_node = check_halt_state_context (mctx,
+                                               mctx->state_log[match_last],
+                                               match_last);
+       }
+      ret = merge_state_array (dfa, sifted_states, lim_states,
+                              match_last + 1);
+      re_free (lim_states);
+      lim_states = NULL;
+      if (BE (ret != REG_NOERROR, 0))
+       goto free_return;
+    }
+  else
+    {
+      sift_ctx_init (&sctx, sifted_states, lim_states, halt_node, match_last);
+      ret = sift_states_backward (mctx, &sctx);
+      re_node_set_free (&sctx.limits);
+      if (BE (ret != REG_NOERROR, 0))
+       goto free_return;
+      if (sifted_states[0] == NULL)
+       {
+         ret = REG_NOMATCH;
+         goto free_return;
+       }
+    }
+  re_free (mctx->state_log);
+  mctx->state_log = sifted_states;
+  sifted_states = NULL;
+  mctx->last_node = halt_node;
+  mctx->match_last = match_last;
+  ret = REG_NOERROR;
+ free_return:
+  re_free (sifted_states);
+  re_free (lim_states);
+  return ret;
+}
+
+/* Acquire an initial state and return it.
+   We must select appropriate initial state depending on the context,
+   since initial states may have constraints like "\<", "^", etc..  */
+
+static inline re_dfastate_t *
+__attribute ((always_inline)) internal_function
+acquire_init_state_context (reg_errcode_t *err, const re_match_context_t *mctx,
+                           Idx idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  if (dfa->init_state->has_constraint)
+    {
+      unsigned int context;
+      context = re_string_context_at (&mctx->input, idx - 1, mctx->eflags);
+      if (IS_WORD_CONTEXT (context))
+       return dfa->init_state_word;
+      else if (IS_ORDINARY_CONTEXT (context))
+       return dfa->init_state;
+      else if (IS_BEGBUF_CONTEXT (context) && IS_NEWLINE_CONTEXT (context))
+       return dfa->init_state_begbuf;
+      else if (IS_NEWLINE_CONTEXT (context))
+       return dfa->init_state_nl;
+      else if (IS_BEGBUF_CONTEXT (context))
+       {
+         /* It is relatively rare case, then calculate on demand.  */
+         return re_acquire_state_context (err, dfa,
+                                          dfa->init_state->entrance_nodes,
+                                          context);
+       }
+      else
+       /* Must not happen?  */
+       return dfa->init_state;
+    }
+  else
+    return dfa->init_state;
+}
+
+/* Check whether the regular expression match input string INPUT or not,
+   and return the index where the matching end.  Return REG_MISSING if
+   there is no match, and return REG_ERROR in case of an error.
+   FL_LONGEST_MATCH means we want the POSIX longest matching.
+   If P_MATCH_FIRST is not NULL, and the match fails, it is set to the
+   next place where we may want to try matching.
+   Note that the matcher assume that the maching starts from the current
+   index of the buffer.  */
+
+static Idx
+internal_function __attribute_warn_unused_result__
+check_matching (re_match_context_t *mctx, bool fl_longest_match,
+               Idx *p_match_first)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx match = 0;
+  Idx match_last = REG_MISSING;
+  Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+  re_dfastate_t *cur_state;
+  bool at_init_state = p_match_first != NULL;
+  Idx next_start_idx = cur_str_idx;
+
+  err = REG_NOERROR;
+  cur_state = acquire_init_state_context (&err, mctx, cur_str_idx);
+  /* An initial state must not be NULL (invalid).  */
+  if (BE (cur_state == NULL, 0))
+    {
+      assert (err == REG_ESPACE);
+      return REG_ERROR;
+    }
+
+  if (mctx->state_log != NULL)
+    {
+      mctx->state_log[cur_str_idx] = cur_state;
+
+      /* Check OP_OPEN_SUBEXP in the initial state in case that we use them
+        later.  E.g. Processing back references.  */
+      if (BE (dfa->nbackref, 0))
+       {
+         at_init_state = false;
+         err = check_subexp_matching_top (mctx, &cur_state->nodes, 0);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+
+         if (cur_state->has_backref)
+           {
+             err = transit_state_bkref (mctx, &cur_state->nodes);
+             if (BE (err != REG_NOERROR, 0))
+               return err;
+           }
+       }
+    }
+
+  /* If the RE accepts NULL string.  */
+  if (BE (cur_state->halt, 0))
+    {
+      if (!cur_state->has_constraint
+         || check_halt_state_context (mctx, cur_state, cur_str_idx))
+       {
+         if (!fl_longest_match)
+           return cur_str_idx;
+         else
+           {
+             match_last = cur_str_idx;
+             match = 1;
+           }
+       }
+    }
+
+  while (!re_string_eoi (&mctx->input))
+    {
+      re_dfastate_t *old_state = cur_state;
+      Idx next_char_idx = re_string_cur_idx (&mctx->input) + 1;
+
+      if (BE (next_char_idx >= mctx->input.bufs_len, 0)
+         || (BE (next_char_idx >= mctx->input.valid_len, 0)
+             && mctx->input.valid_len < mctx->input.len))
+       {
+         err = extend_buffers (mctx);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             assert (err == REG_ESPACE);
+             return REG_ERROR;
+           }
+       }
+
+      cur_state = transit_state (&err, mctx, cur_state);
+      if (mctx->state_log != NULL)
+       cur_state = merge_state_with_log (&err, mctx, cur_state);
+
+      if (cur_state == NULL)
+       {
+         /* Reached the invalid state or an error.  Try to recover a valid
+            state using the state log, if available and if we have not
+            already found a valid (even if not the longest) match.  */
+         if (BE (err != REG_NOERROR, 0))
+           return REG_ERROR;
+
+         if (mctx->state_log == NULL
+             || (match && !fl_longest_match)
+             || (cur_state = find_recover_state (&err, mctx)) == NULL)
+           break;
+       }
+
+      if (BE (at_init_state, 0))
+       {
+         if (old_state == cur_state)
+           next_start_idx = next_char_idx;
+         else
+           at_init_state = false;
+       }
+
+      if (cur_state->halt)
+       {
+         /* Reached a halt state.
+            Check the halt state can satisfy the current context.  */
+         if (!cur_state->has_constraint
+             || check_halt_state_context (mctx, cur_state,
+                                          re_string_cur_idx (&mctx->input)))
+           {
+             /* We found an appropriate halt state.  */
+             match_last = re_string_cur_idx (&mctx->input);
+             match = 1;
+
+             /* We found a match, do not modify match_first below.  */
+             p_match_first = NULL;
+             if (!fl_longest_match)
+               break;
+           }
+       }
+    }
+
+  if (p_match_first)
+    *p_match_first += next_start_idx;
+
+  return match_last;
+}
+
+/* Check NODE match the current context.  */
+
+static bool
+internal_function
+check_halt_node_context (const re_dfa_t *dfa, Idx node, unsigned int context)
+{
+  re_token_type_t type = dfa->nodes[node].type;
+  unsigned int constraint = dfa->nodes[node].constraint;
+  if (type != END_OF_RE)
+    return false;
+  if (!constraint)
+    return true;
+  if (NOT_SATISFY_NEXT_CONSTRAINT (constraint, context))
+    return false;
+  return true;
+}
+
+/* Check the halt state STATE match the current context.
+   Return 0 if not match, if the node, STATE has, is a halt node and
+   match the context, return the node.  */
+
+static Idx
+internal_function
+check_halt_state_context (const re_match_context_t *mctx,
+                         const re_dfastate_t *state, Idx idx)
+{
+  Idx i;
+  unsigned int context;
+#ifdef DEBUG
+  assert (state->halt);
+#endif
+  context = re_string_context_at (&mctx->input, idx, mctx->eflags);
+  for (i = 0; i < state->nodes.nelem; ++i)
+    if (check_halt_node_context (mctx->dfa, state->nodes.elems[i], context))
+      return state->nodes.elems[i];
+  return 0;
+}
+
+/* Compute the next node to which "NFA" transit from NODE("NFA" is a NFA
+   corresponding to the DFA).
+   Return the destination node, and update EPS_VIA_NODES;
+   return REG_MISSING in case of errors.  */
+
+static Idx
+internal_function
+proceed_next_node (const re_match_context_t *mctx, Idx nregs, regmatch_t *regs,
+                  Idx *pidx, Idx node, re_node_set *eps_via_nodes,
+                  struct re_fail_stack_t *fs)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx i;
+  bool ok;
+  if (IS_EPSILON_NODE (dfa->nodes[node].type))
+    {
+      re_node_set *cur_nodes = &mctx->state_log[*pidx]->nodes;
+      re_node_set *edests = &dfa->edests[node];
+      Idx dest_node;
+      ok = re_node_set_insert (eps_via_nodes, node);
+      if (BE (! ok, 0))
+       return REG_ERROR;
+      /* Pick up a valid destination, or return REG_MISSING if none
+        is found.  */
+      for (dest_node = REG_MISSING, i = 0; i < edests->nelem; ++i)
+       {
+         Idx candidate = edests->elems[i];
+         if (!re_node_set_contains (cur_nodes, candidate))
+           continue;
+          if (dest_node == REG_MISSING)
+           dest_node = candidate;
+
+         else
+           {
+             /* In order to avoid infinite loop like "(a*)*", return the second
+                epsilon-transition if the first was already considered.  */
+             if (re_node_set_contains (eps_via_nodes, dest_node))
+               return candidate;
+
+             /* Otherwise, push the second epsilon-transition on the fail 
stack.  */
+             else if (fs != NULL
+                      && push_fail_stack (fs, *pidx, candidate, nregs, regs,
+                                          eps_via_nodes))
+               return REG_ERROR;
+
+             /* We know we are going to exit.  */
+             break;
+           }
+       }
+      return dest_node;
+    }
+  else
+    {
+      Idx naccepted = 0;
+      re_token_type_t type = dfa->nodes[node].type;
+
+#ifdef RE_ENABLE_I18N
+      if (dfa->nodes[node].accept_mb)
+       naccepted = check_node_accept_bytes (dfa, node, &mctx->input, *pidx);
+      else
+#endif /* RE_ENABLE_I18N */
+      if (type == OP_BACK_REF)
+       {
+         Idx subexp_idx = dfa->nodes[node].opr.idx + 1;
+         naccepted = regs[subexp_idx].rm_eo - regs[subexp_idx].rm_so;
+         if (fs != NULL)
+           {
+             if (regs[subexp_idx].rm_so == -1 || regs[subexp_idx].rm_eo == -1)
+               return REG_MISSING;
+             else if (naccepted)
+               {
+                 char *buf = (char *) re_string_get_buffer (&mctx->input);
+                 if (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx,
+                             naccepted) != 0)
+                   return REG_MISSING;
+               }
+           }
+
+         if (naccepted == 0)
+           {
+             Idx dest_node;
+             ok = re_node_set_insert (eps_via_nodes, node);
+             if (BE (! ok, 0))
+               return REG_ERROR;
+             dest_node = dfa->edests[node].elems[0];
+             if (re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+                                       dest_node))
+               return dest_node;
+           }
+       }
+
+      if (naccepted != 0
+         || check_node_accept (mctx, dfa->nodes + node, *pidx))
+       {
+         Idx dest_node = dfa->nexts[node];
+         *pidx = (naccepted == 0) ? *pidx + 1 : *pidx + naccepted;
+         if (fs && (*pidx > mctx->match_last || mctx->state_log[*pidx] == NULL
+                    || !re_node_set_contains (&mctx->state_log[*pidx]->nodes,
+                                              dest_node)))
+           return REG_MISSING;
+         re_node_set_empty (eps_via_nodes);
+         return dest_node;
+       }
+    }
+  return REG_MISSING;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+push_fail_stack (struct re_fail_stack_t *fs, Idx str_idx, Idx dest_node,
+                Idx nregs, regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  reg_errcode_t err;
+  Idx num = fs->num++;
+  if (fs->num == fs->alloc)
+    {
+      struct re_fail_stack_ent_t *new_array;
+      new_array = realloc (fs->stack, (sizeof (struct re_fail_stack_ent_t)
+                                      * fs->alloc * 2));
+      if (new_array == NULL)
+       return REG_ESPACE;
+      fs->alloc *= 2;
+      fs->stack = new_array;
+    }
+  fs->stack[num].idx = str_idx;
+  fs->stack[num].node = dest_node;
+  fs->stack[num].regs = re_malloc (regmatch_t, nregs);
+  if (fs->stack[num].regs == NULL)
+    return REG_ESPACE;
+  memcpy (fs->stack[num].regs, regs, sizeof (regmatch_t) * nregs);
+  err = re_node_set_init_copy (&fs->stack[num].eps_via_nodes, eps_via_nodes);
+  return err;
+}
+
+static Idx
+internal_function
+pop_fail_stack (struct re_fail_stack_t *fs, Idx *pidx, Idx nregs,
+               regmatch_t *regs, re_node_set *eps_via_nodes)
+{
+  Idx num = --fs->num;
+  assert (REG_VALID_INDEX (num));
+  *pidx = fs->stack[num].idx;
+  memcpy (regs, fs->stack[num].regs, sizeof (regmatch_t) * nregs);
+  re_node_set_free (eps_via_nodes);
+  re_free (fs->stack[num].regs);
+  *eps_via_nodes = fs->stack[num].eps_via_nodes;
+  return fs->stack[num].node;
+}
+
+/* Set the positions where the subexpressions are starts/ends to registers
+   PMATCH.
+   Note: We assume that pmatch[0] is already set, and
+   pmatch[i].rm_so == pmatch[i].rm_eo == -1 for 0 < i < nmatch.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch,
+         regmatch_t *pmatch, bool fl_backtrack)
+{
+  const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer;
+  Idx idx, cur_node;
+  re_node_set eps_via_nodes;
+  struct re_fail_stack_t *fs;
+  struct re_fail_stack_t fs_body = { 0, 2, NULL };
+  regmatch_t *prev_idx_match;
+  bool prev_idx_match_malloced = false;
+
+#ifdef DEBUG
+  assert (nmatch > 1);
+  assert (mctx->state_log != NULL);
+#endif
+  if (fl_backtrack)
+    {
+      fs = &fs_body;
+      fs->stack = re_malloc (struct re_fail_stack_ent_t, fs->alloc);
+      if (fs->stack == NULL)
+       return REG_ESPACE;
+    }
+  else
+    fs = NULL;
+
+  cur_node = dfa->init_node;
+  re_node_set_init_empty (&eps_via_nodes);
+
+  if (__libc_use_alloca (nmatch * sizeof (regmatch_t)))
+    prev_idx_match = (regmatch_t *) alloca (nmatch * sizeof (regmatch_t));
+  else
+    {
+      prev_idx_match = re_malloc (regmatch_t, nmatch);
+      if (prev_idx_match == NULL)
+       {
+         free_fail_stack_return (fs);
+         return REG_ESPACE;
+       }
+      prev_idx_match_malloced = true;
+    }
+  memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+
+  for (idx = pmatch[0].rm_so; idx <= pmatch[0].rm_eo ;)
+    {
+      update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch);
+
+      if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node)
+       {
+         Idx reg_idx;
+         if (fs)
+           {
+             for (reg_idx = 0; reg_idx < nmatch; ++reg_idx)
+               if (pmatch[reg_idx].rm_so > -1 && pmatch[reg_idx].rm_eo == -1)
+                 break;
+             if (reg_idx == nmatch)
+               {
+                 re_node_set_free (&eps_via_nodes);
+                 if (prev_idx_match_malloced)
+                   re_free (prev_idx_match);
+                 return free_fail_stack_return (fs);
+               }
+             cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+                                        &eps_via_nodes);
+           }
+         else
+           {
+             re_node_set_free (&eps_via_nodes);
+             if (prev_idx_match_malloced)
+               re_free (prev_idx_match);
+             return REG_NOERROR;
+           }
+       }
+
+      /* Proceed to next node.  */
+      cur_node = proceed_next_node (mctx, nmatch, pmatch, &idx, cur_node,
+                                   &eps_via_nodes, fs);
+
+      if (BE (! REG_VALID_INDEX (cur_node), 0))
+       {
+         if (BE (cur_node == REG_ERROR, 0))
+           {
+             re_node_set_free (&eps_via_nodes);
+             if (prev_idx_match_malloced)
+               re_free (prev_idx_match);
+             free_fail_stack_return (fs);
+             return REG_ESPACE;
+           }
+         if (fs)
+           cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch,
+                                      &eps_via_nodes);
+         else
+           {
+             re_node_set_free (&eps_via_nodes);
+             if (prev_idx_match_malloced)
+               re_free (prev_idx_match);
+             return REG_NOMATCH;
+           }
+       }
+    }
+  re_node_set_free (&eps_via_nodes);
+  if (prev_idx_match_malloced)
+    re_free (prev_idx_match);
+  return free_fail_stack_return (fs);
+}
+
+static reg_errcode_t
+internal_function
+free_fail_stack_return (struct re_fail_stack_t *fs)
+{
+  if (fs)
+    {
+      Idx fs_idx;
+      for (fs_idx = 0; fs_idx < fs->num; ++fs_idx)
+       {
+         re_node_set_free (&fs->stack[fs_idx].eps_via_nodes);
+         re_free (fs->stack[fs_idx].regs);
+       }
+      re_free (fs->stack);
+    }
+  return REG_NOERROR;
+}
+
+static void
+internal_function
+update_regs (const re_dfa_t *dfa, regmatch_t *pmatch,
+            regmatch_t *prev_idx_match, Idx cur_node, Idx cur_idx, Idx nmatch)
+{
+  int type = dfa->nodes[cur_node].type;
+  if (type == OP_OPEN_SUBEXP)
+    {
+      Idx reg_num = dfa->nodes[cur_node].opr.idx + 1;
+
+      /* We are at the first node of this sub expression.  */
+      if (reg_num < nmatch)
+       {
+         pmatch[reg_num].rm_so = cur_idx;
+         pmatch[reg_num].rm_eo = -1;
+       }
+    }
+  else if (type == OP_CLOSE_SUBEXP)
+    {
+      Idx reg_num = dfa->nodes[cur_node].opr.idx + 1;
+      if (reg_num < nmatch)
+       {
+         /* We are at the last node of this sub expression.  */
+         if (pmatch[reg_num].rm_so < cur_idx)
+           {
+             pmatch[reg_num].rm_eo = cur_idx;
+             /* This is a non-empty match or we are not inside an optional
+                subexpression.  Accept this right away.  */
+             memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch);
+           }
+         else
+           {
+             if (dfa->nodes[cur_node].opt_subexp
+                 && prev_idx_match[reg_num].rm_so != -1)
+               /* We transited through an empty match for an optional
+                  subexpression, like (a?)*, and this is not the subexp's
+                  first match.  Copy back the old content of the registers
+                  so that matches of an inner subexpression are undone as
+                  well, like in ((a?))*.  */
+               memcpy (pmatch, prev_idx_match, sizeof (regmatch_t) * nmatch);
+             else
+               /* We completed a subexpression, but it may be part of
+                  an optional one, so do not update PREV_IDX_MATCH.  */
+               pmatch[reg_num].rm_eo = cur_idx;
+           }
+       }
+    }
+}
+
+/* This function checks the STATE_LOG from the SCTX->last_str_idx to 0
+   and sift the nodes in each states according to the following rules.
+   Updated state_log will be wrote to STATE_LOG.
+
+   Rules: We throw away the Node 'a' in the STATE_LOG[STR_IDX] if...
+     1. When STR_IDX == MATCH_LAST(the last index in the state_log):
+       If 'a' isn't the LAST_NODE and 'a' can't epsilon transit to
+       the LAST_NODE, we throw away the node 'a'.
+     2. When 0 <= STR_IDX < MATCH_LAST and 'a' accepts
+       string 's' and transit to 'b':
+       i. If 'b' isn't in the STATE_LOG[STR_IDX+strlen('s')], we throw
+          away the node 'a'.
+       ii. If 'b' is in the STATE_LOG[STR_IDX+strlen('s')] but 'b' is
+           thrown away, we throw away the node 'a'.
+     3. When 0 <= STR_IDX < MATCH_LAST and 'a' epsilon transit to 'b':
+       i. If 'b' isn't in the STATE_LOG[STR_IDX], we throw away the
+          node 'a'.
+       ii. If 'b' is in the STATE_LOG[STR_IDX] but 'b' is thrown away,
+           we throw away the node 'a'.  */
+
+#define STATE_NODE_CONTAINS(state,node) \
+  ((state) != NULL && re_node_set_contains (&(state)->nodes, node))
+
+static reg_errcode_t
+internal_function
+sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx)
+{
+  reg_errcode_t err;
+  int null_cnt = 0;
+  Idx str_idx = sctx->last_str_idx;
+  re_node_set cur_dest;
+
+#ifdef DEBUG
+  assert (mctx->state_log != NULL && mctx->state_log[str_idx] != NULL);
+#endif
+
+  /* Build sifted state_log[str_idx].  It has the nodes which can epsilon
+     transit to the last_node and the last_node itself.  */
+  err = re_node_set_init_1 (&cur_dest, sctx->last_node);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+  if (BE (err != REG_NOERROR, 0))
+    goto free_return;
+
+  /* Then check each states in the state_log.  */
+  while (str_idx > 0)
+    {
+      /* Update counters.  */
+      null_cnt = (sctx->sifted_states[str_idx] == NULL) ? null_cnt + 1 : 0;
+      if (null_cnt > mctx->max_mb_elem_len)
+       {
+         memset (sctx->sifted_states, '\0',
+                 sizeof (re_dfastate_t *) * str_idx);
+         re_node_set_free (&cur_dest);
+         return REG_NOERROR;
+       }
+      re_node_set_empty (&cur_dest);
+      --str_idx;
+
+      if (mctx->state_log[str_idx])
+       {
+         err = build_sifted_states (mctx, sctx, str_idx, &cur_dest);
+         if (BE (err != REG_NOERROR, 0))
+           goto free_return;
+       }
+
+      /* Add all the nodes which satisfy the following conditions:
+        - It can epsilon transit to a node in CUR_DEST.
+        - It is in CUR_SRC.
+        And update state_log.  */
+      err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest);
+      if (BE (err != REG_NOERROR, 0))
+       goto free_return;
+    }
+  err = REG_NOERROR;
+ free_return:
+  re_node_set_free (&cur_dest);
+  return err;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+build_sifted_states (const re_match_context_t *mctx, re_sift_context_t *sctx,
+                    Idx str_idx, re_node_set *cur_dest)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *cur_src = &mctx->state_log[str_idx]->non_eps_nodes;
+  Idx i;
+
+  /* Then build the next sifted state.
+     We build the next sifted state on 'cur_dest', and update
+     'sifted_states[str_idx]' with 'cur_dest'.
+     Note:
+     'cur_dest' is the sifted state from 'state_log[str_idx + 1]'.
+     'cur_src' points the node_set of the old 'state_log[str_idx]'
+     (with the epsilon nodes pre-filtered out).  */
+  for (i = 0; i < cur_src->nelem; i++)
+    {
+      Idx prev_node = cur_src->elems[i];
+      int naccepted = 0;
+      bool ok;
+
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[prev_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept "multi byte".  */
+      if (dfa->nodes[prev_node].accept_mb)
+       naccepted = sift_states_iter_mb (mctx, sctx, prev_node,
+                                        str_idx, sctx->last_str_idx);
+#endif /* RE_ENABLE_I18N */
+
+      /* We don't check backreferences here.
+        See update_cur_sifted_state().  */
+      if (!naccepted
+         && check_node_accept (mctx, dfa->nodes + prev_node, str_idx)
+         && STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + 1],
+                                 dfa->nexts[prev_node]))
+       naccepted = 1;
+
+      if (naccepted == 0)
+       continue;
+
+      if (sctx->limits.nelem)
+       {
+         Idx to_idx = str_idx + naccepted;
+         if (check_dst_limits (mctx, &sctx->limits,
+                               dfa->nexts[prev_node], to_idx,
+                               prev_node, str_idx))
+           continue;
+       }
+      ok = re_node_set_insert (cur_dest, prev_node);
+      if (BE (! ok, 0))
+       return REG_ESPACE;
+    }
+
+  return REG_NOERROR;
+}
+
+/* Helper functions.  */
+
+static reg_errcode_t
+internal_function
+clean_state_log_if_needed (re_match_context_t *mctx, Idx next_state_log_idx)
+{
+  Idx top = mctx->state_log_top;
+
+  if (next_state_log_idx >= mctx->input.bufs_len
+      || (next_state_log_idx >= mctx->input.valid_len
+         && mctx->input.valid_len < mctx->input.len))
+    {
+      reg_errcode_t err;
+      err = extend_buffers (mctx);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+    }
+
+  if (top < next_state_log_idx)
+    {
+      memset (mctx->state_log + top + 1, '\0',
+             sizeof (re_dfastate_t *) * (next_state_log_idx - top));
+      mctx->state_log_top = next_state_log_idx;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+merge_state_array (const re_dfa_t *dfa, re_dfastate_t **dst,
+                  re_dfastate_t **src, Idx num)
+{
+  Idx st_idx;
+  reg_errcode_t err;
+  for (st_idx = 0; st_idx < num; ++st_idx)
+    {
+      if (dst[st_idx] == NULL)
+       dst[st_idx] = src[st_idx];
+      else if (src[st_idx] != NULL)
+       {
+         re_node_set merged_set;
+         err = re_node_set_init_union (&merged_set, &dst[st_idx]->nodes,
+                                       &src[st_idx]->nodes);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+         dst[st_idx] = re_acquire_state (&err, dfa, &merged_set);
+         re_node_set_free (&merged_set);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function
+update_cur_sifted_state (const re_match_context_t *mctx,
+                        re_sift_context_t *sctx, Idx str_idx,
+                        re_node_set *dest_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  const re_node_set *candidates;
+  candidates = ((mctx->state_log[str_idx] == NULL) ? NULL
+               : &mctx->state_log[str_idx]->nodes);
+
+  if (dest_nodes->nelem == 0)
+    sctx->sifted_states[str_idx] = NULL;
+  else
+    {
+      if (candidates)
+       {
+         /* At first, add the nodes which can epsilon transit to a node in
+            DEST_NODE.  */
+         err = add_epsilon_src_nodes (dfa, dest_nodes, candidates);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+
+         /* Then, check the limitations in the current sift_context.  */
+         if (sctx->limits.nelem)
+           {
+             err = check_subexp_limits (dfa, dest_nodes, candidates, 
&sctx->limits,
+                                        mctx->bkref_ents, str_idx);
+             if (BE (err != REG_NOERROR, 0))
+               return err;
+           }
+       }
+
+      sctx->sifted_states[str_idx] = re_acquire_state (&err, dfa, dest_nodes);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+    }
+
+  if (candidates && mctx->state_log[str_idx]->has_backref)
+    {
+      err = sift_states_bkref (mctx, sctx, str_idx, candidates);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes,
+                      const re_node_set *candidates)
+{
+  reg_errcode_t err = REG_NOERROR;
+  Idx i;
+
+  re_dfastate_t *state = re_acquire_state (&err, dfa, dest_nodes);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+
+  if (!state->inveclosure.alloc)
+    {
+      err = re_node_set_alloc (&state->inveclosure, dest_nodes->nelem);
+      if (BE (err != REG_NOERROR, 0))
+       return REG_ESPACE;
+      for (i = 0; i < dest_nodes->nelem; i++)
+       {
+         err = re_node_set_merge (&state->inveclosure,
+                                  dfa->inveclosures + dest_nodes->elems[i]);
+         if (BE (err != REG_NOERROR, 0))
+           return REG_ESPACE;
+       }
+    }
+  return re_node_set_add_intersect (dest_nodes, candidates,
+                                   &state->inveclosure);
+}
+
+static reg_errcode_t
+internal_function
+sub_epsilon_src_nodes (const re_dfa_t *dfa, Idx node, re_node_set *dest_nodes,
+                      const re_node_set *candidates)
+{
+    Idx ecl_idx;
+    reg_errcode_t err;
+    re_node_set *inv_eclosure = dfa->inveclosures + node;
+    re_node_set except_nodes;
+    re_node_set_init_empty (&except_nodes);
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+       Idx cur_node = inv_eclosure->elems[ecl_idx];
+       if (cur_node == node)
+         continue;
+       if (IS_EPSILON_NODE (dfa->nodes[cur_node].type))
+         {
+           Idx edst1 = dfa->edests[cur_node].elems[0];
+           Idx edst2 = ((dfa->edests[cur_node].nelem > 1)
+                        ? dfa->edests[cur_node].elems[1] : REG_MISSING);
+           if ((!re_node_set_contains (inv_eclosure, edst1)
+                && re_node_set_contains (dest_nodes, edst1))
+               || (REG_VALID_NONZERO_INDEX (edst2)
+                   && !re_node_set_contains (inv_eclosure, edst2)
+                   && re_node_set_contains (dest_nodes, edst2)))
+             {
+               err = re_node_set_add_intersect (&except_nodes, candidates,
+                                                dfa->inveclosures + cur_node);
+               if (BE (err != REG_NOERROR, 0))
+                 {
+                   re_node_set_free (&except_nodes);
+                   return err;
+                 }
+             }
+         }
+      }
+    for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx)
+      {
+       Idx cur_node = inv_eclosure->elems[ecl_idx];
+       if (!re_node_set_contains (&except_nodes, cur_node))
+         {
+           Idx idx = re_node_set_contains (dest_nodes, cur_node) - 1;
+           re_node_set_remove_at (dest_nodes, idx);
+         }
+      }
+    re_node_set_free (&except_nodes);
+    return REG_NOERROR;
+}
+
+static bool
+internal_function
+check_dst_limits (const re_match_context_t *mctx, const re_node_set *limits,
+                 Idx dst_node, Idx dst_idx, Idx src_node, Idx src_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx lim_idx, src_pos, dst_pos;
+
+  Idx dst_bkref_idx = search_cur_bkref_entry (mctx, dst_idx);
+  Idx src_bkref_idx = search_cur_bkref_entry (mctx, src_idx);
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      Idx subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = mctx->bkref_ents + limits->elems[lim_idx];
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+
+      dst_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+                                          subexp_idx, dst_node, dst_idx,
+                                          dst_bkref_idx);
+      src_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx],
+                                          subexp_idx, src_node, src_idx,
+                                          src_bkref_idx);
+
+      /* In case of:
+        <src> <dst> ( <subexp> )
+        ( <subexp> ) <src> <dst>
+        ( <subexp1> <src> <subexp2> <dst> <subexp3> )  */
+      if (src_pos == dst_pos)
+       continue; /* This is unrelated limitation.  */
+      else
+       return true;
+    }
+  return false;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries,
+                            Idx subexp_idx, Idx from_node, Idx bkref_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  const re_node_set *eclosures = dfa->eclosures + from_node;
+  Idx node_idx;
+
+  /* Else, we are on the boundary: examine the nodes on the epsilon
+     closure.  */
+  for (node_idx = 0; node_idx < eclosures->nelem; ++node_idx)
+    {
+      Idx node = eclosures->elems[node_idx];
+      switch (dfa->nodes[node].type)
+       {
+       case OP_BACK_REF:
+         if (bkref_idx != REG_MISSING)
+           {
+             struct re_backref_cache_entry *ent = mctx->bkref_ents + bkref_idx;
+             do
+               {
+                 Idx dst;
+                 int cpos;
+
+                 if (ent->node != node)
+                   continue;
+
+                 if (subexp_idx < BITSET_WORD_BITS
+                     && !(ent->eps_reachable_subexps_map
+                          & ((bitset_word_t) 1 << subexp_idx)))
+                   continue;
+
+                 /* Recurse trying to reach the OP_OPEN_SUBEXP and
+                    OP_CLOSE_SUBEXP cases below.  But, if the
+                    destination node is the same node as the source
+                    node, don't recurse because it would cause an
+                    infinite loop: a regex that exhibits this behavior
+                    is ()\1*\1*  */
+                 dst = dfa->edests[node].elems[0];
+                 if (dst == from_node)
+                   {
+                     if (boundaries & 1)
+                       return -1;
+                     else /* if (boundaries & 2) */
+                       return 0;
+                   }
+
+                 cpos =
+                   check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+                                                dst, bkref_idx);
+                 if (cpos == -1 /* && (boundaries & 1) */)
+                   return -1;
+                 if (cpos == 0 && (boundaries & 2))
+                   return 0;
+
+                 if (subexp_idx < BITSET_WORD_BITS)
+                   ent->eps_reachable_subexps_map
+                     &= ~((bitset_word_t) 1 << subexp_idx);
+               }
+             while (ent++->more);
+           }
+         break;
+
+       case OP_OPEN_SUBEXP:
+         if ((boundaries & 1) && subexp_idx == dfa->nodes[node].opr.idx)
+           return -1;
+         break;
+
+       case OP_CLOSE_SUBEXP:
+         if ((boundaries & 2) && subexp_idx == dfa->nodes[node].opr.idx)
+           return 0;
+         break;
+
+       default:
+           break;
+       }
+    }
+
+  return (boundaries & 2) ? 1 : 0;
+}
+
+static int
+internal_function
+check_dst_limits_calc_pos (const re_match_context_t *mctx, Idx limit,
+                          Idx subexp_idx, Idx from_node, Idx str_idx,
+                          Idx bkref_idx)
+{
+  struct re_backref_cache_entry *lim = mctx->bkref_ents + limit;
+  int boundaries;
+
+  /* If we are outside the range of the subexpression, return -1 or 1.  */
+  if (str_idx < lim->subexp_from)
+    return -1;
+
+  if (lim->subexp_to < str_idx)
+    return 1;
+
+  /* If we are within the subexpression, return 0.  */
+  boundaries = (str_idx == lim->subexp_from);
+  boundaries |= (str_idx == lim->subexp_to) << 1;
+  if (boundaries == 0)
+    return 0;
+
+  /* Else, examine epsilon closure.  */
+  return check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx,
+                                     from_node, bkref_idx);
+}
+
+/* Check the limitations of sub expressions LIMITS, and remove the nodes
+   which are against limitations from DEST_NODES. */
+
+static reg_errcode_t
+internal_function
+check_subexp_limits (const re_dfa_t *dfa, re_node_set *dest_nodes,
+                    const re_node_set *candidates, re_node_set *limits,
+                    struct re_backref_cache_entry *bkref_ents, Idx str_idx)
+{
+  reg_errcode_t err;
+  Idx node_idx, lim_idx;
+
+  for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx)
+    {
+      Idx subexp_idx;
+      struct re_backref_cache_entry *ent;
+      ent = bkref_ents + limits->elems[lim_idx];
+
+      if (str_idx <= ent->subexp_from || ent->str_idx < str_idx)
+       continue; /* This is unrelated limitation.  */
+
+      subexp_idx = dfa->nodes[ent->node].opr.idx;
+      if (ent->subexp_to == str_idx)
+       {
+         Idx ops_node = REG_MISSING;
+         Idx cls_node = REG_MISSING;
+         for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+           {
+             Idx node = dest_nodes->elems[node_idx];
+             re_token_type_t type = dfa->nodes[node].type;
+             if (type == OP_OPEN_SUBEXP
+                 && subexp_idx == dfa->nodes[node].opr.idx)
+               ops_node = node;
+             else if (type == OP_CLOSE_SUBEXP
+                      && subexp_idx == dfa->nodes[node].opr.idx)
+               cls_node = node;
+           }
+
+         /* Check the limitation of the open subexpression.  */
+         /* Note that (ent->subexp_to = str_idx != ent->subexp_from).  */
+         if (REG_VALID_INDEX (ops_node))
+           {
+             err = sub_epsilon_src_nodes (dfa, ops_node, dest_nodes,
+                                          candidates);
+             if (BE (err != REG_NOERROR, 0))
+               return err;
+           }
+
+         /* Check the limitation of the close subexpression.  */
+         if (REG_VALID_INDEX (cls_node))
+           for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+             {
+               Idx node = dest_nodes->elems[node_idx];
+               if (!re_node_set_contains (dfa->inveclosures + node,
+                                          cls_node)
+                   && !re_node_set_contains (dfa->eclosures + node,
+                                             cls_node))
+                 {
+                   /* It is against this limitation.
+                      Remove it form the current sifted state.  */
+                   err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+                                                candidates);
+                   if (BE (err != REG_NOERROR, 0))
+                     return err;
+                   --node_idx;
+                 }
+             }
+       }
+      else /* (ent->subexp_to != str_idx)  */
+       {
+         for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx)
+           {
+             Idx node = dest_nodes->elems[node_idx];
+             re_token_type_t type = dfa->nodes[node].type;
+             if (type == OP_CLOSE_SUBEXP || type == OP_OPEN_SUBEXP)
+               {
+                 if (subexp_idx != dfa->nodes[node].opr.idx)
+                   continue;
+                 /* It is against this limitation.
+                    Remove it form the current sifted state.  */
+                 err = sub_epsilon_src_nodes (dfa, node, dest_nodes,
+                                              candidates);
+                 if (BE (err != REG_NOERROR, 0))
+                   return err;
+               }
+           }
+       }
+    }
+  return REG_NOERROR;
+}
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx,
+                  Idx str_idx, const re_node_set *candidates)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx node_idx, node;
+  re_sift_context_t local_sctx;
+  Idx first_idx = search_cur_bkref_entry (mctx, str_idx);
+
+  if (first_idx == REG_MISSING)
+    return REG_NOERROR;
+
+  local_sctx.sifted_states = NULL; /* Mark that it hasn't been initialized.  */
+
+  for (node_idx = 0; node_idx < candidates->nelem; ++node_idx)
+    {
+      Idx enabled_idx;
+      re_token_type_t type;
+      struct re_backref_cache_entry *entry;
+      node = candidates->elems[node_idx];
+      type = dfa->nodes[node].type;
+      /* Avoid infinite loop for the REs like "()\1+".  */
+      if (node == sctx->last_node && str_idx == sctx->last_str_idx)
+       continue;
+      if (type != OP_BACK_REF)
+       continue;
+
+      entry = mctx->bkref_ents + first_idx;
+      enabled_idx = first_idx;
+      do
+       {
+         Idx subexp_len;
+         Idx to_idx;
+         Idx dst_node;
+         bool ok;
+         re_dfastate_t *cur_state;
+
+         if (entry->node != node)
+           continue;
+         subexp_len = entry->subexp_to - entry->subexp_from;
+         to_idx = str_idx + subexp_len;
+         dst_node = (subexp_len ? dfa->nexts[node]
+                     : dfa->edests[node].elems[0]);
+
+         if (to_idx > sctx->last_str_idx
+             || sctx->sifted_states[to_idx] == NULL
+             || !STATE_NODE_CONTAINS (sctx->sifted_states[to_idx], dst_node)
+             || check_dst_limits (mctx, &sctx->limits, node,
+                                  str_idx, dst_node, to_idx))
+           continue;
+
+         if (local_sctx.sifted_states == NULL)
+           {
+             local_sctx = *sctx;
+             err = re_node_set_init_copy (&local_sctx.limits, &sctx->limits);
+             if (BE (err != REG_NOERROR, 0))
+               goto free_return;
+           }
+         local_sctx.last_node = node;
+         local_sctx.last_str_idx = str_idx;
+         ok = re_node_set_insert (&local_sctx.limits, enabled_idx);
+         if (BE (! ok, 0))
+           {
+             err = REG_ESPACE;
+             goto free_return;
+           }
+         cur_state = local_sctx.sifted_states[str_idx];
+         err = sift_states_backward (mctx, &local_sctx);
+         if (BE (err != REG_NOERROR, 0))
+           goto free_return;
+         if (sctx->limited_states != NULL)
+           {
+             err = merge_state_array (dfa, sctx->limited_states,
+                                      local_sctx.sifted_states,
+                                      str_idx + 1);
+             if (BE (err != REG_NOERROR, 0))
+               goto free_return;
+           }
+         local_sctx.sifted_states[str_idx] = cur_state;
+         re_node_set_remove (&local_sctx.limits, enabled_idx);
+
+         /* mctx->bkref_ents may have changed, reload the pointer.  */
+         entry = mctx->bkref_ents + enabled_idx;
+       }
+      while (enabled_idx++, entry++->more);
+    }
+  err = REG_NOERROR;
+ free_return:
+  if (local_sctx.sifted_states != NULL)
+    {
+      re_node_set_free (&local_sctx.limits);
+    }
+
+  return err;
+}
+
+
+#ifdef RE_ENABLE_I18N
+static int
+internal_function
+sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx,
+                    Idx node_idx, Idx str_idx, Idx max_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  int naccepted;
+  /* Check the node can accept "multi byte".  */
+  naccepted = check_node_accept_bytes (dfa, node_idx, &mctx->input, str_idx);
+  if (naccepted > 0 && str_idx + naccepted <= max_str_idx &&
+      !STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + naccepted],
+                           dfa->nexts[node_idx]))
+    /* The node can't accept the "multi byte", or the
+       destination was already thrown away, then the node
+       could't accept the current input "multi byte".   */
+    naccepted = 0;
+  /* Otherwise, it is sure that the node could accept
+     'naccepted' bytes input.  */
+  return naccepted;
+}
+#endif /* RE_ENABLE_I18N */
+
+
+/* Functions for state transition.  */
+
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte, and update STATE_LOG if necessary.
+   If STATE can accept a multibyte char/collating element/back reference
+   update the destination of STATE_LOG.  */
+
+static re_dfastate_t *
+internal_function __attribute_warn_unused_result__
+transit_state (reg_errcode_t *err, re_match_context_t *mctx,
+              re_dfastate_t *state)
+{
+  re_dfastate_t **trtable;
+  unsigned char ch;
+
+#ifdef RE_ENABLE_I18N
+  /* If the current state can accept multibyte.  */
+  if (BE (state->accept_mb, 0))
+    {
+      *err = transit_state_mb (mctx, state);
+      if (BE (*err != REG_NOERROR, 0))
+       return NULL;
+    }
+#endif /* RE_ENABLE_I18N */
+
+  /* Then decide the next state with the single byte.  */
+#if 0
+  if (0)
+    /* don't use transition table  */
+    return transit_state_sb (err, mctx, state);
+#endif
+
+  /* Use transition table  */
+  ch = re_string_fetch_byte (&mctx->input);
+  for (;;)
+    {
+      trtable = state->trtable;
+      if (BE (trtable != NULL, 1))
+       return trtable[ch];
+
+      trtable = state->word_trtable;
+      if (BE (trtable != NULL, 1))
+       {
+         unsigned int context;
+         context
+           = re_string_context_at (&mctx->input,
+                                   re_string_cur_idx (&mctx->input) - 1,
+                                   mctx->eflags);
+         if (IS_WORD_CONTEXT (context))
+           return trtable[ch + SBC_MAX];
+         else
+           return trtable[ch];
+       }
+
+      if (!build_trtable (mctx->dfa, state))
+       {
+         *err = REG_ESPACE;
+         return NULL;
+       }
+
+      /* Retry, we now have a transition table.  */
+    }
+}
+
+/* Update the state_log if we need */
+static re_dfastate_t *
+internal_function
+merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx,
+                     re_dfastate_t *next_state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx cur_idx = re_string_cur_idx (&mctx->input);
+
+  if (cur_idx > mctx->state_log_top)
+    {
+      mctx->state_log[cur_idx] = next_state;
+      mctx->state_log_top = cur_idx;
+    }
+  else if (mctx->state_log[cur_idx] == 0)
+    {
+      mctx->state_log[cur_idx] = next_state;
+    }
+  else
+    {
+      re_dfastate_t *pstate;
+      unsigned int context;
+      re_node_set next_nodes, *log_nodes, *table_nodes = NULL;
+      /* If (state_log[cur_idx] != 0), it implies that cur_idx is
+        the destination of a multibyte char/collating element/
+        back reference.  Then the next state is the union set of
+        these destinations and the results of the transition table.  */
+      pstate = mctx->state_log[cur_idx];
+      log_nodes = pstate->entrance_nodes;
+      if (next_state != NULL)
+       {
+         table_nodes = next_state->entrance_nodes;
+         *err = re_node_set_init_union (&next_nodes, table_nodes,
+                                            log_nodes);
+         if (BE (*err != REG_NOERROR, 0))
+           return NULL;
+       }
+      else
+       next_nodes = *log_nodes;
+      /* Note: We already add the nodes of the initial state,
+        then we don't need to add them here.  */
+
+      context = re_string_context_at (&mctx->input,
+                                     re_string_cur_idx (&mctx->input) - 1,
+                                     mctx->eflags);
+      next_state = mctx->state_log[cur_idx]
+       = re_acquire_state_context (err, dfa, &next_nodes, context);
+      /* We don't need to check errors here, since the return value of
+        this function is next_state and ERR is already set.  */
+
+      if (table_nodes != NULL)
+       re_node_set_free (&next_nodes);
+    }
+
+  if (BE (dfa->nbackref, 0) && next_state != NULL)
+    {
+      /* Check OP_OPEN_SUBEXP in the current state in case that we use them
+        later.  We must check them here, since the back references in the
+        next state might use them.  */
+      *err = check_subexp_matching_top (mctx, &next_state->nodes,
+                                       cur_idx);
+      if (BE (*err != REG_NOERROR, 0))
+       return NULL;
+
+      /* If the next state has back references.  */
+      if (next_state->has_backref)
+       {
+         *err = transit_state_bkref (mctx, &next_state->nodes);
+         if (BE (*err != REG_NOERROR, 0))
+           return NULL;
+         next_state = mctx->state_log[cur_idx];
+       }
+    }
+
+  return next_state;
+}
+
+/* Skip bytes in the input that correspond to part of a
+   multi-byte match, then look in the log for a state
+   from which to restart matching.  */
+static re_dfastate_t *
+internal_function
+find_recover_state (reg_errcode_t *err, re_match_context_t *mctx)
+{
+  re_dfastate_t *cur_state;
+  do
+    {
+      Idx max = mctx->state_log_top;
+      Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+
+      do
+       {
+         if (++cur_str_idx > max)
+           return NULL;
+         re_string_skip_bytes (&mctx->input, 1);
+       }
+      while (mctx->state_log[cur_str_idx] == NULL);
+
+      cur_state = merge_state_with_log (err, mctx, NULL);
+    }
+  while (*err == REG_NOERROR && cur_state == NULL);
+  return cur_state;
+}
+
+/* Helper functions for transit_state.  */
+
+/* From the node set CUR_NODES, pick up the nodes whose types are
+   OP_OPEN_SUBEXP and which have corresponding back references in the regular
+   expression. And register them to use them later for evaluating the
+   correspoding back references.  */
+
+static reg_errcode_t
+internal_function
+check_subexp_matching_top (re_match_context_t *mctx, re_node_set *cur_nodes,
+                          Idx str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx node_idx;
+  reg_errcode_t err;
+
+  /* TODO: This isn't efficient.
+          Because there might be more than one nodes whose types are
+          OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+          nodes.
+          E.g. RE: (a){2}  */
+  for (node_idx = 0; node_idx < cur_nodes->nelem; ++node_idx)
+    {
+      Idx node = cur_nodes->elems[node_idx];
+      if (dfa->nodes[node].type == OP_OPEN_SUBEXP
+         && dfa->nodes[node].opr.idx < BITSET_WORD_BITS
+         && (dfa->used_bkref_map
+             & ((bitset_word_t) 1 << dfa->nodes[node].opr.idx)))
+       {
+         err = match_ctx_add_subtop (mctx, node, str_idx);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+    }
+  return REG_NOERROR;
+}
+
+#if 0
+/* Return the next state to which the current state STATE will transit by
+   accepting the current input byte.  */
+
+static re_dfastate_t *
+transit_state_sb (reg_errcode_t *err, re_match_context_t *mctx,
+                 re_dfastate_t *state)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  re_node_set next_nodes;
+  re_dfastate_t *next_state;
+  Idx node_cnt, cur_str_idx = re_string_cur_idx (&mctx->input);
+  unsigned int context;
+
+  *err = re_node_set_alloc (&next_nodes, state->nodes.nelem + 1);
+  if (BE (*err != REG_NOERROR, 0))
+    return NULL;
+  for (node_cnt = 0; node_cnt < state->nodes.nelem; ++node_cnt)
+    {
+      Idx cur_node = state->nodes.elems[node_cnt];
+      if (check_node_accept (mctx, dfa->nodes + cur_node, cur_str_idx))
+       {
+         *err = re_node_set_merge (&next_nodes,
+                                   dfa->eclosures + dfa->nexts[cur_node]);
+         if (BE (*err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return NULL;
+           }
+       }
+    }
+  context = re_string_context_at (&mctx->input, cur_str_idx, mctx->eflags);
+  next_state = re_acquire_state_context (err, dfa, &next_nodes, context);
+  /* We don't need to check errors here, since the return value of
+     this function is next_state and ERR is already set.  */
+
+  re_node_set_free (&next_nodes);
+  re_string_skip_bytes (&mctx->input, 1);
+  return next_state;
+}
+#endif
+
+#ifdef RE_ENABLE_I18N
+static reg_errcode_t
+internal_function
+transit_state_mb (re_match_context_t *mctx, re_dfastate_t *pstate)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx i;
+
+  for (i = 0; i < pstate->nodes.nelem; ++i)
+    {
+      re_node_set dest_nodes, *new_nodes;
+      Idx cur_node_idx = pstate->nodes.elems[i];
+      int naccepted;
+      Idx dest_idx;
+      unsigned int context;
+      re_dfastate_t *dest_state;
+
+      if (!dfa->nodes[cur_node_idx].accept_mb)
+       continue;
+
+      if (dfa->nodes[cur_node_idx].constraint)
+       {
+         context = re_string_context_at (&mctx->input,
+                                         re_string_cur_idx (&mctx->input),
+                                         mctx->eflags);
+         if (NOT_SATISFY_NEXT_CONSTRAINT (dfa->nodes[cur_node_idx].constraint,
+                                          context))
+           continue;
+       }
+
+      /* How many bytes the node can accept?  */
+      naccepted = check_node_accept_bytes (dfa, cur_node_idx, &mctx->input,
+                                          re_string_cur_idx (&mctx->input));
+      if (naccepted == 0)
+       continue;
+
+      /* The node can accepts 'naccepted' bytes.  */
+      dest_idx = re_string_cur_idx (&mctx->input) + naccepted;
+      mctx->max_mb_elem_len = ((mctx->max_mb_elem_len < naccepted) ? naccepted
+                              : mctx->max_mb_elem_len);
+      err = clean_state_log_if_needed (mctx, dest_idx);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+#ifdef DEBUG
+      assert (dfa->nexts[cur_node_idx] != REG_MISSING);
+#endif
+      new_nodes = dfa->eclosures + dfa->nexts[cur_node_idx];
+
+      dest_state = mctx->state_log[dest_idx];
+      if (dest_state == NULL)
+       dest_nodes = *new_nodes;
+      else
+       {
+         err = re_node_set_init_union (&dest_nodes,
+                                       dest_state->entrance_nodes, new_nodes);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+      context = re_string_context_at (&mctx->input, dest_idx - 1,
+                                     mctx->eflags);
+      mctx->state_log[dest_idx]
+       = re_acquire_state_context (&err, dfa, &dest_nodes, context);
+      if (dest_state != NULL)
+       re_node_set_free (&dest_nodes);
+      if (BE (mctx->state_log[dest_idx] == NULL && err != REG_NOERROR, 0))
+       return err;
+    }
+  return REG_NOERROR;
+}
+#endif /* RE_ENABLE_I18N */
+
+static reg_errcode_t
+internal_function
+transit_state_bkref (re_match_context_t *mctx, const re_node_set *nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx i;
+  Idx cur_str_idx = re_string_cur_idx (&mctx->input);
+
+  for (i = 0; i < nodes->nelem; ++i)
+    {
+      Idx dest_str_idx, prev_nelem, bkc_idx;
+      Idx node_idx = nodes->elems[i];
+      unsigned int context;
+      const re_token_t *node = dfa->nodes + node_idx;
+      re_node_set *new_dest_nodes;
+
+      /* Check whether 'node' is a backreference or not.  */
+      if (node->type != OP_BACK_REF)
+       continue;
+
+      if (node->constraint)
+       {
+         context = re_string_context_at (&mctx->input, cur_str_idx,
+                                         mctx->eflags);
+         if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+           continue;
+       }
+
+      /* 'node' is a backreference.
+        Check the substring which the substring matched.  */
+      bkc_idx = mctx->nbkref_ents;
+      err = get_subexp (mctx, node_idx, cur_str_idx);
+      if (BE (err != REG_NOERROR, 0))
+       goto free_return;
+
+      /* And add the epsilon closures (which is 'new_dest_nodes') of
+        the backreference to appropriate state_log.  */
+#ifdef DEBUG
+      assert (dfa->nexts[node_idx] != REG_MISSING);
+#endif
+      for (; bkc_idx < mctx->nbkref_ents; ++bkc_idx)
+       {
+         Idx subexp_len;
+         re_dfastate_t *dest_state;
+         struct re_backref_cache_entry *bkref_ent;
+         bkref_ent = mctx->bkref_ents + bkc_idx;
+         if (bkref_ent->node != node_idx || bkref_ent->str_idx != cur_str_idx)
+           continue;
+         subexp_len = bkref_ent->subexp_to - bkref_ent->subexp_from;
+         new_dest_nodes = (subexp_len == 0
+                           ? dfa->eclosures + dfa->edests[node_idx].elems[0]
+                           : dfa->eclosures + dfa->nexts[node_idx]);
+         dest_str_idx = (cur_str_idx + bkref_ent->subexp_to
+                         - bkref_ent->subexp_from);
+         context = re_string_context_at (&mctx->input, dest_str_idx - 1,
+                                         mctx->eflags);
+         dest_state = mctx->state_log[dest_str_idx];
+         prev_nelem = ((mctx->state_log[cur_str_idx] == NULL) ? 0
+                       : mctx->state_log[cur_str_idx]->nodes.nelem);
+         /* Add 'new_dest_node' to state_log.  */
+         if (dest_state == NULL)
+           {
+             mctx->state_log[dest_str_idx]
+               = re_acquire_state_context (&err, dfa, new_dest_nodes,
+                                           context);
+             if (BE (mctx->state_log[dest_str_idx] == NULL
+                     && err != REG_NOERROR, 0))
+               goto free_return;
+           }
+         else
+           {
+             re_node_set dest_nodes;
+             err = re_node_set_init_union (&dest_nodes,
+                                           dest_state->entrance_nodes,
+                                           new_dest_nodes);
+             if (BE (err != REG_NOERROR, 0))
+               {
+                 re_node_set_free (&dest_nodes);
+                 goto free_return;
+               }
+             mctx->state_log[dest_str_idx]
+               = re_acquire_state_context (&err, dfa, &dest_nodes, context);
+             re_node_set_free (&dest_nodes);
+             if (BE (mctx->state_log[dest_str_idx] == NULL
+                     && err != REG_NOERROR, 0))
+               goto free_return;
+           }
+         /* We need to check recursively if the backreference can epsilon
+            transit.  */
+         if (subexp_len == 0
+             && mctx->state_log[cur_str_idx]->nodes.nelem > prev_nelem)
+           {
+             err = check_subexp_matching_top (mctx, new_dest_nodes,
+                                              cur_str_idx);
+             if (BE (err != REG_NOERROR, 0))
+               goto free_return;
+             err = transit_state_bkref (mctx, new_dest_nodes);
+             if (BE (err != REG_NOERROR, 0))
+               goto free_return;
+           }
+       }
+    }
+  err = REG_NOERROR;
+ free_return:
+  return err;
+}
+
+/* Enumerate all the candidates which the backreference BKREF_NODE can match
+   at BKREF_STR_IDX, and register them by match_ctx_add_entry().
+   Note that we might collect inappropriate candidates here.
+   However, the cost of checking them strictly here is too high, then we
+   delay these checking for prune_impossible_nodes().  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+get_subexp (re_match_context_t *mctx, Idx bkref_node, Idx bkref_str_idx)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  Idx subexp_num, sub_top_idx;
+  const char *buf = (const char *) re_string_get_buffer (&mctx->input);
+  /* Return if we have already checked BKREF_NODE at BKREF_STR_IDX.  */
+  Idx cache_idx = search_cur_bkref_entry (mctx, bkref_str_idx);
+  if (cache_idx != REG_MISSING)
+    {
+      const struct re_backref_cache_entry *entry
+       = mctx->bkref_ents + cache_idx;
+      do
+       if (entry->node == bkref_node)
+         return REG_NOERROR; /* We already checked it.  */
+      while (entry++->more);
+    }
+
+  subexp_num = dfa->nodes[bkref_node].opr.idx;
+
+  /* For each sub expression  */
+  for (sub_top_idx = 0; sub_top_idx < mctx->nsub_tops; ++sub_top_idx)
+    {
+      reg_errcode_t err;
+      re_sub_match_top_t *sub_top = mctx->sub_tops[sub_top_idx];
+      re_sub_match_last_t *sub_last;
+      Idx sub_last_idx, sl_str, bkref_str_off;
+
+      if (dfa->nodes[sub_top->node].opr.idx != subexp_num)
+       continue; /* It isn't related.  */
+
+      sl_str = sub_top->str_idx;
+      bkref_str_off = bkref_str_idx;
+      /* At first, check the last node of sub expressions we already
+        evaluated.  */
+      for (sub_last_idx = 0; sub_last_idx < sub_top->nlasts; ++sub_last_idx)
+       {
+         regoff_t sl_str_diff;
+         sub_last = sub_top->lasts[sub_last_idx];
+         sl_str_diff = sub_last->str_idx - sl_str;
+         /* The matched string by the sub expression match with the substring
+            at the back reference?  */
+         if (sl_str_diff > 0)
+           {
+             if (BE (bkref_str_off + sl_str_diff > mctx->input.valid_len, 0))
+               {
+                 /* Not enough chars for a successful match.  */
+                 if (bkref_str_off + sl_str_diff > mctx->input.len)
+                   break;
+
+                 err = clean_state_log_if_needed (mctx,
+                                                  bkref_str_off
+                                                  + sl_str_diff);
+                 if (BE (err != REG_NOERROR, 0))
+                   return err;
+                 buf = (const char *) re_string_get_buffer (&mctx->input);
+               }
+             if (memcmp (buf + bkref_str_off, buf + sl_str, sl_str_diff) != 0)
+               /* We don't need to search this sub expression any more.  */
+               break;
+           }
+         bkref_str_off += sl_str_diff;
+         sl_str += sl_str_diff;
+         err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+                               bkref_str_idx);
+
+         /* Reload buf, since the preceding call might have reallocated
+            the buffer.  */
+         buf = (const char *) re_string_get_buffer (&mctx->input);
+
+         if (err == REG_NOMATCH)
+           continue;
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+
+      if (sub_last_idx < sub_top->nlasts)
+       continue;
+      if (sub_last_idx > 0)
+       ++sl_str;
+      /* Then, search for the other last nodes of the sub expression.  */
+      for (; sl_str <= bkref_str_idx; ++sl_str)
+       {
+         Idx cls_node;
+         regoff_t sl_str_off;
+         const re_node_set *nodes;
+         sl_str_off = sl_str - sub_top->str_idx;
+         /* The matched string by the sub expression match with the substring
+            at the back reference?  */
+         if (sl_str_off > 0)
+           {
+             if (BE (bkref_str_off >= mctx->input.valid_len, 0))
+               {
+                 /* If we are at the end of the input, we cannot match.  */
+                 if (bkref_str_off >= mctx->input.len)
+                   break;
+
+                 err = extend_buffers (mctx);
+                 if (BE (err != REG_NOERROR, 0))
+                   return err;
+
+                 buf = (const char *) re_string_get_buffer (&mctx->input);
+               }
+             if (buf [bkref_str_off++] != buf[sl_str - 1])
+               break; /* We don't need to search this sub expression
+                         any more.  */
+           }
+         if (mctx->state_log[sl_str] == NULL)
+           continue;
+         /* Does this state have a ')' of the sub expression?  */
+         nodes = &mctx->state_log[sl_str]->nodes;
+         cls_node = find_subexp_node (dfa, nodes, subexp_num,
+                                      OP_CLOSE_SUBEXP);
+         if (cls_node == REG_MISSING)
+           continue; /* No.  */
+         if (sub_top->path == NULL)
+           {
+             sub_top->path = calloc (sizeof (state_array_t),
+                                     sl_str - sub_top->str_idx + 1);
+             if (sub_top->path == NULL)
+               return REG_ESPACE;
+           }
+         /* Can the OP_OPEN_SUBEXP node arrive the OP_CLOSE_SUBEXP node
+            in the current context?  */
+         err = check_arrival (mctx, sub_top->path, sub_top->node,
+                              sub_top->str_idx, cls_node, sl_str,
+                              OP_CLOSE_SUBEXP);
+         if (err == REG_NOMATCH)
+             continue;
+         if (BE (err != REG_NOERROR, 0))
+             return err;
+         sub_last = match_ctx_add_sublast (sub_top, cls_node, sl_str);
+         if (BE (sub_last == NULL, 0))
+           return REG_ESPACE;
+         err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node,
+                               bkref_str_idx);
+         if (err == REG_NOMATCH)
+           continue;
+       }
+    }
+  return REG_NOERROR;
+}
+
+/* Helper functions for get_subexp().  */
+
+/* Check SUB_LAST can arrive to the back reference BKREF_NODE at BKREF_STR.
+   If it can arrive, register the sub expression expressed with SUB_TOP
+   and SUB_LAST.  */
+
+static reg_errcode_t
+internal_function
+get_subexp_sub (re_match_context_t *mctx, const re_sub_match_top_t *sub_top,
+               re_sub_match_last_t *sub_last, Idx bkref_node, Idx bkref_str)
+{
+  reg_errcode_t err;
+  Idx to_idx;
+  /* Can the subexpression arrive the back reference?  */
+  err = check_arrival (mctx, &sub_last->path, sub_last->node,
+                      sub_last->str_idx, bkref_node, bkref_str,
+                      OP_OPEN_SUBEXP);
+  if (err != REG_NOERROR)
+    return err;
+  err = match_ctx_add_entry (mctx, bkref_node, bkref_str, sub_top->str_idx,
+                            sub_last->str_idx);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  to_idx = bkref_str + sub_last->str_idx - sub_top->str_idx;
+  return clean_state_log_if_needed (mctx, to_idx);
+}
+
+/* Find the first node which is '(' or ')' and whose index is SUBEXP_IDX.
+   Search '(' if FL_OPEN, or search ')' otherwise.
+   TODO: This function isn't efficient...
+        Because there might be more than one nodes whose types are
+        OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all
+        nodes.
+        E.g. RE: (a){2}  */
+
+static Idx
+internal_function
+find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes,
+                 Idx subexp_idx, int type)
+{
+  Idx cls_idx;
+  for (cls_idx = 0; cls_idx < nodes->nelem; ++cls_idx)
+    {
+      Idx cls_node = nodes->elems[cls_idx];
+      const re_token_t *node = dfa->nodes + cls_node;
+      if (node->type == type
+         && node->opr.idx == subexp_idx)
+       return cls_node;
+    }
+  return REG_MISSING;
+}
+
+/* Check whether the node TOP_NODE at TOP_STR can arrive to the node
+   LAST_NODE at LAST_STR.  We record the path onto PATH since it will be
+   heavily reused.
+   Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+check_arrival (re_match_context_t *mctx, state_array_t *path, Idx top_node,
+              Idx top_str, Idx last_node, Idx last_str, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err = REG_NOERROR;
+  Idx subexp_num, backup_cur_idx, str_idx, null_cnt;
+  re_dfastate_t *cur_state = NULL;
+  re_node_set *cur_nodes, next_nodes;
+  re_dfastate_t **backup_state_log;
+  unsigned int context;
+
+  subexp_num = dfa->nodes[top_node].opr.idx;
+  /* Extend the buffer if we need.  */
+  if (BE (path->alloc < last_str + mctx->max_mb_elem_len + 1, 0))
+    {
+      re_dfastate_t **new_array;
+      Idx old_alloc = path->alloc;
+      Idx new_alloc = old_alloc + last_str + mctx->max_mb_elem_len + 1;
+      if (BE (new_alloc < old_alloc, 0)
+         || BE (SIZE_MAX / sizeof (re_dfastate_t *) < new_alloc, 0))
+       return REG_ESPACE;
+      new_array = re_realloc (path->array, re_dfastate_t *, new_alloc);
+      if (BE (new_array == NULL, 0))
+       return REG_ESPACE;
+      path->array = new_array;
+      path->alloc = new_alloc;
+      memset (new_array + old_alloc, '\0',
+             sizeof (re_dfastate_t *) * (path->alloc - old_alloc));
+    }
+
+  str_idx = path->next_idx ? path->next_idx : top_str;
+
+  /* Temporary modify MCTX.  */
+  backup_state_log = mctx->state_log;
+  backup_cur_idx = mctx->input.cur_idx;
+  mctx->state_log = path->array;
+  mctx->input.cur_idx = str_idx;
+
+  /* Setup initial node set.  */
+  context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+  if (str_idx == top_str)
+    {
+      err = re_node_set_init_1 (&next_nodes, top_node);
+      if (BE (err != REG_NOERROR, 0))
+       return err;
+      err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+      if (BE (err != REG_NOERROR, 0))
+       {
+         re_node_set_free (&next_nodes);
+         return err;
+       }
+    }
+  else
+    {
+      cur_state = mctx->state_log[str_idx];
+      if (cur_state && cur_state->has_backref)
+       {
+         err = re_node_set_init_copy (&next_nodes, &cur_state->nodes);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+      else
+       re_node_set_init_empty (&next_nodes);
+    }
+  if (str_idx == top_str || (cur_state && cur_state->has_backref))
+    {
+      if (next_nodes.nelem)
+       {
+         err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+                                   subexp_num, type);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return err;
+           }
+       }
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+       {
+         re_node_set_free (&next_nodes);
+         return err;
+       }
+      mctx->state_log[str_idx] = cur_state;
+    }
+
+  for (null_cnt = 0; str_idx < last_str && null_cnt <= mctx->max_mb_elem_len;)
+    {
+      re_node_set_empty (&next_nodes);
+      if (mctx->state_log[str_idx + 1])
+       {
+         err = re_node_set_merge (&next_nodes,
+                                  &mctx->state_log[str_idx + 1]->nodes);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return err;
+           }
+       }
+      if (cur_state)
+       {
+         err = check_arrival_add_next_nodes (mctx, str_idx,
+                                             &cur_state->non_eps_nodes,
+                                             &next_nodes);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return err;
+           }
+       }
+      ++str_idx;
+      if (next_nodes.nelem)
+       {
+         err = check_arrival_expand_ecl (dfa, &next_nodes, subexp_num, type);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return err;
+           }
+         err = expand_bkref_cache (mctx, &next_nodes, str_idx,
+                                   subexp_num, type);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&next_nodes);
+             return err;
+           }
+       }
+      context = re_string_context_at (&mctx->input, str_idx - 1, mctx->eflags);
+      cur_state = re_acquire_state_context (&err, dfa, &next_nodes, context);
+      if (BE (cur_state == NULL && err != REG_NOERROR, 0))
+       {
+         re_node_set_free (&next_nodes);
+         return err;
+       }
+      mctx->state_log[str_idx] = cur_state;
+      null_cnt = cur_state == NULL ? null_cnt + 1 : 0;
+    }
+  re_node_set_free (&next_nodes);
+  cur_nodes = (mctx->state_log[last_str] == NULL ? NULL
+              : &mctx->state_log[last_str]->nodes);
+  path->next_idx = str_idx;
+
+  /* Fix MCTX.  */
+  mctx->state_log = backup_state_log;
+  mctx->input.cur_idx = backup_cur_idx;
+
+  /* Then check the current node set has the node LAST_NODE.  */
+  if (cur_nodes != NULL && re_node_set_contains (cur_nodes, last_node))
+    return REG_NOERROR;
+
+  return REG_NOMATCH;
+}
+
+/* Helper functions for check_arrival.  */
+
+/* Calculate the destination nodes of CUR_NODES at STR_IDX, and append them
+   to NEXT_NODES.
+   TODO: This function is similar to the functions transit_state*(),
+        however this function has many additional works.
+        Can't we unify them?  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+check_arrival_add_next_nodes (re_match_context_t *mctx, Idx str_idx,
+                             re_node_set *cur_nodes, re_node_set *next_nodes)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  bool ok;
+  Idx cur_idx;
+#ifdef RE_ENABLE_I18N
+  reg_errcode_t err = REG_NOERROR;
+#endif
+  re_node_set union_set;
+  re_node_set_init_empty (&union_set);
+  for (cur_idx = 0; cur_idx < cur_nodes->nelem; ++cur_idx)
+    {
+      int naccepted = 0;
+      Idx cur_node = cur_nodes->elems[cur_idx];
+#ifdef DEBUG
+      re_token_type_t type = dfa->nodes[cur_node].type;
+      assert (!IS_EPSILON_NODE (type));
+#endif
+#ifdef RE_ENABLE_I18N
+      /* If the node may accept "multi byte".  */
+      if (dfa->nodes[cur_node].accept_mb)
+       {
+         naccepted = check_node_accept_bytes (dfa, cur_node, &mctx->input,
+                                              str_idx);
+         if (naccepted > 1)
+           {
+             re_dfastate_t *dest_state;
+             Idx next_node = dfa->nexts[cur_node];
+             Idx next_idx = str_idx + naccepted;
+             dest_state = mctx->state_log[next_idx];
+             re_node_set_empty (&union_set);
+             if (dest_state)
+               {
+                 err = re_node_set_merge (&union_set, &dest_state->nodes);
+                 if (BE (err != REG_NOERROR, 0))
+                   {
+                     re_node_set_free (&union_set);
+                     return err;
+                   }
+               }
+             ok = re_node_set_insert (&union_set, next_node);
+             if (BE (! ok, 0))
+               {
+                 re_node_set_free (&union_set);
+                 return REG_ESPACE;
+               }
+             mctx->state_log[next_idx] = re_acquire_state (&err, dfa,
+                                                           &union_set);
+             if (BE (mctx->state_log[next_idx] == NULL
+                     && err != REG_NOERROR, 0))
+               {
+                 re_node_set_free (&union_set);
+                 return err;
+               }
+           }
+       }
+#endif /* RE_ENABLE_I18N */
+      if (naccepted
+         || check_node_accept (mctx, dfa->nodes + cur_node, str_idx))
+       {
+         ok = re_node_set_insert (next_nodes, dfa->nexts[cur_node]);
+         if (BE (! ok, 0))
+           {
+             re_node_set_free (&union_set);
+             return REG_ESPACE;
+           }
+       }
+    }
+  re_node_set_free (&union_set);
+  return REG_NOERROR;
+}
+
+/* For all the nodes in CUR_NODES, add the epsilon closures of them to
+   CUR_NODES, however exclude the nodes which are:
+    - inside the sub expression whose number is EX_SUBEXP, if FL_OPEN.
+    - out of the sub expression whose number is EX_SUBEXP, if !FL_OPEN.
+*/
+
+static reg_errcode_t
+internal_function
+check_arrival_expand_ecl (const re_dfa_t *dfa, re_node_set *cur_nodes,
+                         Idx ex_subexp, int type)
+{
+  reg_errcode_t err;
+  Idx idx, outside_node;
+  re_node_set new_nodes;
+#ifdef DEBUG
+  assert (cur_nodes->nelem);
+#endif
+  err = re_node_set_alloc (&new_nodes, cur_nodes->nelem);
+  if (BE (err != REG_NOERROR, 0))
+    return err;
+  /* Create a new node set NEW_NODES with the nodes which are epsilon
+     closures of the node in CUR_NODES.  */
+
+  for (idx = 0; idx < cur_nodes->nelem; ++idx)
+    {
+      Idx cur_node = cur_nodes->elems[idx];
+      const re_node_set *eclosure = dfa->eclosures + cur_node;
+      outside_node = find_subexp_node (dfa, eclosure, ex_subexp, type);
+      if (outside_node == REG_MISSING)
+       {
+         /* There are no problematic nodes, just merge them.  */
+         err = re_node_set_merge (&new_nodes, eclosure);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&new_nodes);
+             return err;
+           }
+       }
+      else
+       {
+         /* There are problematic nodes, re-calculate incrementally.  */
+         err = check_arrival_expand_ecl_sub (dfa, &new_nodes, cur_node,
+                                             ex_subexp, type);
+         if (BE (err != REG_NOERROR, 0))
+           {
+             re_node_set_free (&new_nodes);
+             return err;
+           }
+       }
+    }
+  re_node_set_free (cur_nodes);
+  *cur_nodes = new_nodes;
+  return REG_NOERROR;
+}
+
+/* Helper function for check_arrival_expand_ecl.
+   Check incrementally the epsilon closure of TARGET, and if it isn't
+   problematic append it to DST_NODES.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+check_arrival_expand_ecl_sub (const re_dfa_t *dfa, re_node_set *dst_nodes,
+                             Idx target, Idx ex_subexp, int type)
+{
+  Idx cur_node;
+  for (cur_node = target; !re_node_set_contains (dst_nodes, cur_node);)
+    {
+      bool ok;
+
+      if (dfa->nodes[cur_node].type == type
+         && dfa->nodes[cur_node].opr.idx == ex_subexp)
+       {
+         if (type == OP_CLOSE_SUBEXP)
+           {
+             ok = re_node_set_insert (dst_nodes, cur_node);
+             if (BE (! ok, 0))
+               return REG_ESPACE;
+           }
+         break;
+       }
+      ok = re_node_set_insert (dst_nodes, cur_node);
+      if (BE (! ok, 0))
+       return REG_ESPACE;
+      if (dfa->edests[cur_node].nelem == 0)
+       break;
+      if (dfa->edests[cur_node].nelem == 2)
+       {
+         reg_errcode_t err;
+         err = check_arrival_expand_ecl_sub (dfa, dst_nodes,
+                                             dfa->edests[cur_node].elems[1],
+                                             ex_subexp, type);
+         if (BE (err != REG_NOERROR, 0))
+           return err;
+       }
+      cur_node = dfa->edests[cur_node].elems[0];
+    }
+  return REG_NOERROR;
+}
+
+
+/* For all the back references in the current state, calculate the
+   destination of the back references by the appropriate entry
+   in MCTX->BKREF_ENTS.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+expand_bkref_cache (re_match_context_t *mctx, re_node_set *cur_nodes,
+                   Idx cur_str, Idx subexp_num, int type)
+{
+  const re_dfa_t *const dfa = mctx->dfa;
+  reg_errcode_t err;
+  Idx cache_idx_start = search_cur_bkref_entry (mctx, cur_str);
+  struct re_backref_cache_entry *ent;
+
+  if (cache_idx_start == REG_MISSING)
+    return REG_NOERROR;
+
+ restart:
+  ent = mctx->bkref_ents + cache_idx_start;
+  do
+    {
+      Idx to_idx, next_node;
+
+      /* Is this entry ENT is appropriate?  */
+      if (!re_node_set_contains (cur_nodes, ent->node))
+       continue; /* No.  */
+
+      to_idx = cur_str + ent->subexp_to - ent->subexp_from;
+      /* Calculate the destination of the back reference, and append it
+        to MCTX->STATE_LOG.  */
+      if (to_idx == cur_str)
+       {
+         /* The backreference did epsilon transit, we must re-check all the
+            node in the current state.  */
+         re_node_set new_dests;
+         reg_errcode_t err2, err3;
+         next_node = dfa->edests[ent->node].elems[0];
+         if (re_node_set_contains (cur_nodes, next_node))
+           continue;
+         err = re_node_set_init_1 (&new_dests, next_node);
+         err2 = check_arrival_expand_ecl (dfa, &new_dests, subexp_num, type);
+         err3 = re_node_set_merge (cur_nodes, &new_dests);
+         re_node_set_free (&new_dests);
+         if (BE (err != REG_NOERROR || err2 != REG_NOERROR
+                 || err3 != REG_NOERROR, 0))
+           {
+             err = (err != REG_NOERROR ? err
+                    : (err2 != REG_NOERROR ? err2 : err3));
+             return err;
+           }
+         /* TODO: It is still inefficient...  */
+         goto restart;
+       }
+      else
+       {
+         re_node_set union_set;
+         next_node = dfa->nexts[ent->node];
+         if (mctx->state_log[to_idx])
+           {
+             bool ok;
+             if (re_node_set_contains (&mctx->state_log[to_idx]->nodes,
+                                       next_node))
+               continue;
+             err = re_node_set_init_copy (&union_set,
+                                          &mctx->state_log[to_idx]->nodes);
+             ok = re_node_set_insert (&union_set, next_node);
+             if (BE (err != REG_NOERROR || ! ok, 0))
+               {
+                 re_node_set_free (&union_set);
+                 err = err != REG_NOERROR ? err : REG_ESPACE;
+                 return err;
+               }
+           }
+         else
+           {
+             err = re_node_set_init_1 (&union_set, next_node);
+             if (BE (err != REG_NOERROR, 0))
+               return err;
+           }
+         mctx->state_log[to_idx] = re_acquire_state (&err, dfa, &union_set);
+         re_node_set_free (&union_set);
+         if (BE (mctx->state_log[to_idx] == NULL
+                 && err != REG_NOERROR, 0))
+           return err;
+       }
+    }
+  while (ent++->more);
+  return REG_NOERROR;
+}
+
+/* Build transition table for the state.
+   Return true if successful.  */
+
+static bool
+internal_function
+build_trtable (const re_dfa_t *dfa, re_dfastate_t *state)
+{
+  reg_errcode_t err;
+  Idx i, j;
+  int ch;
+  bool need_word_trtable = false;
+  bitset_word_t elem, mask;
+  bool dests_node_malloced = false;
+  bool dest_states_malloced = false;
+  Idx ndests; /* Number of the destination states from 'state'.  */
+  re_dfastate_t **trtable;
+  re_dfastate_t **dest_states = NULL, **dest_states_word, **dest_states_nl;
+  re_node_set follows, *dests_node;
+  bitset_t *dests_ch;
+  bitset_t acceptable;
+
+  struct dests_alloc
+  {
+    re_node_set dests_node[SBC_MAX];
+    bitset_t dests_ch[SBC_MAX];
+  } *dests_alloc;
+
+  /* We build DFA states which corresponds to the destination nodes
+     from 'state'.  'dests_node[i]' represents the nodes which i-th
+     destination state contains, and 'dests_ch[i]' represents the
+     characters which i-th destination state accepts.  */
+  if (__libc_use_alloca (sizeof (struct dests_alloc)))
+    dests_alloc = (struct dests_alloc *) alloca (sizeof (struct dests_alloc));
+  else
+    {
+      dests_alloc = re_malloc (struct dests_alloc, 1);
+      if (BE (dests_alloc == NULL, 0))
+       return false;
+      dests_node_malloced = true;
+    }
+  dests_node = dests_alloc->dests_node;
+  dests_ch = dests_alloc->dests_ch;
+
+  /* Initialize transiton table.  */
+  state->word_trtable = state->trtable = NULL;
+
+  /* At first, group all nodes belonging to 'state' into several
+     destinations.  */
+  ndests = group_nodes_into_DFAstates (dfa, state, dests_node, dests_ch);
+  if (BE (! REG_VALID_NONZERO_INDEX (ndests), 0))
+    {
+      if (dests_node_malloced)
+       free (dests_alloc);
+      if (ndests == 0)
+       {
+         state->trtable = (re_dfastate_t **)
+           calloc (sizeof (re_dfastate_t *), SBC_MAX);
+          if (BE (state->trtable == NULL, 0))
+            return false;
+         return true;
+       }
+      return false;
+    }
+
+  err = re_node_set_alloc (&follows, ndests + 1);
+  if (BE (err != REG_NOERROR, 0))
+    goto out_free;
+
+  /* Avoid arithmetic overflow in size calculation.  */
+  if (BE ((((SIZE_MAX - (sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX)
+           / (3 * sizeof (re_dfastate_t *)))
+          < ndests),
+         0))
+    goto out_free;
+
+  if (__libc_use_alloca ((sizeof (re_node_set) + sizeof (bitset_t)) * SBC_MAX
+                        + ndests * 3 * sizeof (re_dfastate_t *)))
+    dest_states = (re_dfastate_t **)
+      alloca (ndests * 3 * sizeof (re_dfastate_t *));
+  else
+    {
+      dest_states = (re_dfastate_t **)
+       malloc (ndests * 3 * sizeof (re_dfastate_t *));
+      if (BE (dest_states == NULL, 0))
+       {
+out_free:
+         if (dest_states_malloced)
+           free (dest_states);
+         re_node_set_free (&follows);
+         for (i = 0; i < ndests; ++i)
+           re_node_set_free (dests_node + i);
+         if (dests_node_malloced)
+           free (dests_alloc);
+         return false;
+       }
+      dest_states_malloced = true;
+    }
+  dest_states_word = dest_states + ndests;
+  dest_states_nl = dest_states_word + ndests;
+  bitset_empty (acceptable);
+
+  /* Then build the states for all destinations.  */
+  for (i = 0; i < ndests; ++i)
+    {
+      Idx next_node;
+      re_node_set_empty (&follows);
+      /* Merge the follows of this destination states.  */
+      for (j = 0; j < dests_node[i].nelem; ++j)
+       {
+         next_node = dfa->nexts[dests_node[i].elems[j]];
+         if (next_node != REG_MISSING)
+           {
+             err = re_node_set_merge (&follows, dfa->eclosures + next_node);
+             if (BE (err != REG_NOERROR, 0))
+               goto out_free;
+           }
+       }
+      dest_states[i] = re_acquire_state_context (&err, dfa, &follows, 0);
+      if (BE (dest_states[i] == NULL && err != REG_NOERROR, 0))
+       goto out_free;
+      /* If the new state has context constraint,
+        build appropriate states for these contexts.  */
+      if (dest_states[i]->has_constraint)
+       {
+         dest_states_word[i] = re_acquire_state_context (&err, dfa, &follows,
+                                                         CONTEXT_WORD);
+         if (BE (dest_states_word[i] == NULL && err != REG_NOERROR, 0))
+           goto out_free;
+
+         if (dest_states[i] != dest_states_word[i] && dfa->mb_cur_max > 1)
+           need_word_trtable = true;
+
+         dest_states_nl[i] = re_acquire_state_context (&err, dfa, &follows,
+                                                       CONTEXT_NEWLINE);
+         if (BE (dest_states_nl[i] == NULL && err != REG_NOERROR, 0))
+           goto out_free;
+       }
+      else
+       {
+         dest_states_word[i] = dest_states[i];
+         dest_states_nl[i] = dest_states[i];
+       }
+      bitset_merge (acceptable, dests_ch[i]);
+    }
+
+  if (!BE (need_word_trtable, 0))
+    {
+      /* We don't care about whether the following character is a word
+        character, or we are in a single-byte character set so we can
+        discern by looking at the character code: allocate a
+        256-entry transition table.  */
+      trtable = state->trtable =
+       (re_dfastate_t **) calloc (sizeof (re_dfastate_t *), SBC_MAX);
+      if (BE (trtable == NULL, 0))
+       goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+       for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+            elem;
+            mask <<= 1, elem >>= 1, ++ch)
+         if (BE (elem & 1, 0))
+           {
+             /* There must be exactly one destination which accepts
+                character ch.  See group_nodes_into_DFAstates.  */
+             for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+               ;
+
+             /* j-th destination accepts the word character ch.  */
+             if (dfa->word_char[i] & mask)
+               trtable[ch] = dest_states_word[j];
+             else
+               trtable[ch] = dest_states[j];
+           }
+    }
+  else
+    {
+      /* We care about whether the following character is a word
+        character, and we are in a multi-byte character set: discern
+        by looking at the character code: build two 256-entry
+        transition tables, one starting at trtable[0] and one
+        starting at trtable[SBC_MAX].  */
+      trtable = state->word_trtable =
+       (re_dfastate_t **) calloc (sizeof (re_dfastate_t *), 2 * SBC_MAX);
+      if (BE (trtable == NULL, 0))
+       goto out_free;
+
+      /* For all characters ch...:  */
+      for (i = 0; i < BITSET_WORDS; ++i)
+       for (ch = i * BITSET_WORD_BITS, elem = acceptable[i], mask = 1;
+            elem;
+            mask <<= 1, elem >>= 1, ++ch)
+         if (BE (elem & 1, 0))
+           {
+             /* There must be exactly one destination which accepts
+                character ch.  See group_nodes_into_DFAstates.  */
+             for (j = 0; (dests_ch[j][i] & mask) == 0; ++j)
+               ;
+
+             /* j-th destination accepts the word character ch.  */
+             trtable[ch] = dest_states[j];
+             trtable[ch + SBC_MAX] = dest_states_word[j];
+           }
+    }
+
+  /* new line */
+  if (bitset_contain (acceptable, NEWLINE_CHAR))
+    {
+      /* The current state accepts newline character.  */
+      for (j = 0; j < ndests; ++j)
+       if (bitset_contain (dests_ch[j], NEWLINE_CHAR))
+         {
+           /* k-th destination accepts newline character.  */
+           trtable[NEWLINE_CHAR] = dest_states_nl[j];
+           if (need_word_trtable)
+             trtable[NEWLINE_CHAR + SBC_MAX] = dest_states_nl[j];
+           /* There must be only one destination which accepts
+              newline.  See group_nodes_into_DFAstates.  */
+           break;
+         }
+    }
+
+  if (dest_states_malloced)
+    free (dest_states);
+
+  re_node_set_free (&follows);
+  for (i = 0; i < ndests; ++i)
+    re_node_set_free (dests_node + i);
+
+  if (dests_node_malloced)
+    free (dests_alloc);
+
+  return true;
+}
+
+/* Group all nodes belonging to STATE into several destinations.
+   Then for all destinations, set the nodes belonging to the destination
+   to DESTS_NODE[i] and set the characters accepted by the destination
+   to DEST_CH[i].  This function return the number of destinations.  */
+
+static Idx
+internal_function
+group_nodes_into_DFAstates (const re_dfa_t *dfa, const re_dfastate_t *state,
+                           re_node_set *dests_node, bitset_t *dests_ch)
+{
+  reg_errcode_t err;
+  bool ok;
+  Idx i, j, k;
+  Idx ndests; /* Number of the destinations from 'state'.  */
+  bitset_t accepts; /* Characters a node can accept.  */
+  const re_node_set *cur_nodes = &state->nodes;
+  bitset_empty (accepts);
+  ndests = 0;
+
+  /* For all the nodes belonging to 'state',  */
+  for (i = 0; i < cur_nodes->nelem; ++i)
+    {
+      re_token_t *node = &dfa->nodes[cur_nodes->elems[i]];
+      re_token_type_t type = node->type;
+      unsigned int constraint = node->constraint;
+
+      /* Enumerate all single byte character this node can accept.  */
+      if (type == CHARACTER)
+       bitset_set (accepts, node->opr.c);
+      else if (type == SIMPLE_BRACKET)
+       {
+         bitset_merge (accepts, node->opr.sbcset);
+       }
+      else if (type == OP_PERIOD)
+       {
+#ifdef RE_ENABLE_I18N
+         if (dfa->mb_cur_max > 1)
+           bitset_merge (accepts, dfa->sb_char);
+         else
+#endif
+           bitset_set_all (accepts);
+         if (!(dfa->syntax & RE_DOT_NEWLINE))
+           bitset_clear (accepts, '\n');
+         if (dfa->syntax & RE_DOT_NOT_NULL)
+           bitset_clear (accepts, '\0');
+       }
+#ifdef RE_ENABLE_I18N
+      else if (type == OP_UTF8_PERIOD)
+       {
+         if (ASCII_CHARS % BITSET_WORD_BITS == 0)
+           memset (accepts, -1, ASCII_CHARS / CHAR_BIT);
+         else
+           bitset_merge (accepts, utf8_sb_map);
+         if (!(dfa->syntax & RE_DOT_NEWLINE))
+           bitset_clear (accepts, '\n');
+         if (dfa->syntax & RE_DOT_NOT_NULL)
+           bitset_clear (accepts, '\0');
+       }
+#endif
+      else
+       continue;
+
+      /* Check the 'accepts' and sift the characters which are not
+        match it the context.  */
+      if (constraint)
+       {
+         if (constraint & NEXT_NEWLINE_CONSTRAINT)
+           {
+             bool accepts_newline = bitset_contain (accepts, NEWLINE_CHAR);
+             bitset_empty (accepts);
+             if (accepts_newline)
+               bitset_set (accepts, NEWLINE_CHAR);
+             else
+               continue;
+           }
+         if (constraint & NEXT_ENDBUF_CONSTRAINT)
+           {
+             bitset_empty (accepts);
+             continue;
+           }
+
+         if (constraint & NEXT_WORD_CONSTRAINT)
+           {
+             bitset_word_t any_set = 0;
+             if (type == CHARACTER && !node->word_char)
+               {
+                 bitset_empty (accepts);
+                 continue;
+               }
+#ifdef RE_ENABLE_I18N
+             if (dfa->mb_cur_max > 1)
+               for (j = 0; j < BITSET_WORDS; ++j)
+                 any_set |= (accepts[j] &= (dfa->word_char[j] | 
~dfa->sb_char[j]));
+             else
+#endif
+               for (j = 0; j < BITSET_WORDS; ++j)
+                 any_set |= (accepts[j] &= dfa->word_char[j]);
+             if (!any_set)
+               continue;
+           }
+         if (constraint & NEXT_NOTWORD_CONSTRAINT)
+           {
+             bitset_word_t any_set = 0;
+             if (type == CHARACTER && node->word_char)
+               {
+                 bitset_empty (accepts);
+                 continue;
+               }
+#ifdef RE_ENABLE_I18N
+             if (dfa->mb_cur_max > 1)
+               for (j = 0; j < BITSET_WORDS; ++j)
+                 any_set |= (accepts[j] &= ~(dfa->word_char[j] & 
dfa->sb_char[j]));
+             else
+#endif
+               for (j = 0; j < BITSET_WORDS; ++j)
+                 any_set |= (accepts[j] &= ~dfa->word_char[j]);
+             if (!any_set)
+               continue;
+           }
+       }
+
+      /* Then divide 'accepts' into DFA states, or create a new
+        state.  Above, we make sure that accepts is not empty.  */
+      for (j = 0; j < ndests; ++j)
+       {
+         bitset_t intersec; /* Intersection sets, see below.  */
+         bitset_t remains;
+         /* Flags, see below.  */
+         bitset_word_t has_intersec, not_subset, not_consumed;
+
+         /* Optimization, skip if this state doesn't accept the character.  */
+         if (type == CHARACTER && !bitset_contain (dests_ch[j], node->opr.c))
+           continue;
+
+         /* Enumerate the intersection set of this state and 'accepts'.  */
+         has_intersec = 0;
+         for (k = 0; k < BITSET_WORDS; ++k)
+           has_intersec |= intersec[k] = accepts[k] & dests_ch[j][k];
+         /* And skip if the intersection set is empty.  */
+         if (!has_intersec)
+           continue;
+
+         /* Then check if this state is a subset of 'accepts'.  */
+         not_subset = not_consumed = 0;
+         for (k = 0; k < BITSET_WORDS; ++k)
+           {
+             not_subset |= remains[k] = ~accepts[k] & dests_ch[j][k];
+             not_consumed |= accepts[k] = accepts[k] & ~dests_ch[j][k];
+           }
+
+         /* If this state isn't a subset of 'accepts', create a
+            new group state, which has the 'remains'. */
+         if (not_subset)
+           {
+             bitset_copy (dests_ch[ndests], remains);
+             bitset_copy (dests_ch[j], intersec);
+             err = re_node_set_init_copy (dests_node + ndests, &dests_node[j]);
+             if (BE (err != REG_NOERROR, 0))
+               goto error_return;
+             ++ndests;
+           }
+
+         /* Put the position in the current group. */
+         ok = re_node_set_insert (&dests_node[j], cur_nodes->elems[i]);
+         if (BE (! ok, 0))
+           goto error_return;
+
+         /* If all characters are consumed, go to next node. */
+         if (!not_consumed)
+           break;
+       }
+      /* Some characters remain, create a new group. */
+      if (j == ndests)
+       {
+         bitset_copy (dests_ch[ndests], accepts);
+         err = re_node_set_init_1 (dests_node + ndests, cur_nodes->elems[i]);
+         if (BE (err != REG_NOERROR, 0))
+           goto error_return;
+         ++ndests;
+         bitset_empty (accepts);
+       }
+    }
+  return ndests;
+ error_return:
+  for (j = 0; j < ndests; ++j)
+    re_node_set_free (dests_node + j);
+  return REG_MISSING;
+}
+
+#ifdef RE_ENABLE_I18N
+/* Check how many bytes the node 'dfa->nodes[node_idx]' accepts.
+   Return the number of the bytes the node accepts.
+   STR_IDX is the current index of the input string.
+
+   This function handles the nodes which can accept one character, or
+   one collating element like '.', '[a-z]', opposite to the other nodes
+   can only accept one byte.  */
+
+static int
+internal_function
+check_node_accept_bytes (const re_dfa_t *dfa, Idx node_idx,
+                        const re_string_t *input, Idx str_idx)
+{
+  const re_token_t *node = dfa->nodes + node_idx;
+  int char_len, elem_len;
+  Idx i;
+
+  if (BE (node->type == OP_UTF8_PERIOD, 0))
+    {
+      unsigned char c = re_string_byte_at (input, str_idx), d;
+      if (BE (c < 0xc2, 1))
+       return 0;
+
+      if (str_idx + 2 > input->len)
+       return 0;
+
+      d = re_string_byte_at (input, str_idx + 1);
+      if (c < 0xe0)
+       return (d < 0x80 || d > 0xbf) ? 0 : 2;
+      else if (c < 0xf0)
+       {
+         char_len = 3;
+         if (c == 0xe0 && d < 0xa0)
+           return 0;
+       }
+      else if (c < 0xf8)
+       {
+         char_len = 4;
+         if (c == 0xf0 && d < 0x90)
+           return 0;
+       }
+      else if (c < 0xfc)
+       {
+         char_len = 5;
+         if (c == 0xf8 && d < 0x88)
+           return 0;
+       }
+      else if (c < 0xfe)
+       {
+         char_len = 6;
+         if (c == 0xfc && d < 0x84)
+           return 0;
+       }
+      else
+       return 0;
+
+      if (str_idx + char_len > input->len)
+       return 0;
+
+      for (i = 1; i < char_len; ++i)
+       {
+         d = re_string_byte_at (input, str_idx + i);
+         if (d < 0x80 || d > 0xbf)
+           return 0;
+       }
+      return char_len;
+    }
+
+  char_len = re_string_char_size_at (input, str_idx);
+  if (node->type == OP_PERIOD)
+    {
+      if (char_len <= 1)
+       return 0;
+      /* FIXME: I don't think this if is needed, as both '\n'
+        and '\0' are char_len == 1.  */
+      /* '.' accepts any one character except the following two cases.  */
+      if ((!(dfa->syntax & RE_DOT_NEWLINE) &&
+          re_string_byte_at (input, str_idx) == '\n') ||
+         ((dfa->syntax & RE_DOT_NOT_NULL) &&
+          re_string_byte_at (input, str_idx) == '\0'))
+       return 0;
+      return char_len;
+    }
+
+  elem_len = re_string_elem_size_at (input, str_idx);
+  if ((elem_len <= 1 && char_len <= 1) || char_len == 0)
+    return 0;
+
+  if (node->type == COMPLEX_BRACKET)
+    {
+      const re_charset_t *cset = node->opr.mbcset;
+# ifdef _LIBC
+      const unsigned char *pin
+       = ((const unsigned char *) re_string_get_buffer (input) + str_idx);
+      Idx j;
+      uint32_t nrules;
+# endif /* _LIBC */
+      int match_len = 0;
+      wchar_t wc = ((cset->nranges || cset->nchar_classes || cset->nmbchars)
+                   ? re_string_wchar_at (input, str_idx) : 0);
+
+      /* match with multibyte character?  */
+      for (i = 0; i < cset->nmbchars; ++i)
+       if (wc == cset->mbchars[i])
+         {
+           match_len = char_len;
+           goto check_node_accept_bytes_match;
+         }
+      /* match with character_class?  */
+      for (i = 0; i < cset->nchar_classes; ++i)
+       {
+         wctype_t wt = cset->char_classes[i];
+         if (__iswctype (wc, wt))
+           {
+             match_len = char_len;
+             goto check_node_accept_bytes_match;
+           }
+       }
+
+# ifdef _LIBC
+      nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+      if (nrules != 0)
+       {
+         unsigned int in_collseq = 0;
+         const int32_t *table, *indirect;
+         const unsigned char *weights, *extra;
+         const char *collseqwc;
+         int32_t idx;
+         /* This #include defines a local function!  */
+#  include <locale/weight.h>
+
+         /* match with collating_symbol?  */
+         if (cset->ncoll_syms)
+           extra = (const unsigned char *)
+             _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+         for (i = 0; i < cset->ncoll_syms; ++i)
+           {
+             const unsigned char *coll_sym = extra + cset->coll_syms[i];
+             /* Compare the length of input collating element and
+                the length of current collating element.  */
+             if (*coll_sym != elem_len)
+               continue;
+             /* Compare each bytes.  */
+             for (j = 0; j < *coll_sym; j++)
+               if (pin[j] != coll_sym[1 + j])
+                 break;
+             if (j == *coll_sym)
+               {
+                 /* Match if every bytes is equal.  */
+                 match_len = j;
+                 goto check_node_accept_bytes_match;
+               }
+           }
+
+         if (cset->nranges)
+           {
+             if (elem_len <= char_len)
+               {
+                 collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
+                 in_collseq = __collseq_table_lookup (collseqwc, wc);
+               }
+             else
+               in_collseq = find_collation_sequence_value (pin, elem_len);
+           }
+         /* match with range expression?  */
+         for (i = 0; i < cset->nranges; ++i)
+           if (cset->range_starts[i] <= in_collseq
+               && in_collseq <= cset->range_ends[i])
+             {
+               match_len = elem_len;
+               goto check_node_accept_bytes_match;
+             }
+
+         /* match with equivalence_class?  */
+         if (cset->nequiv_classes)
+           {
+             const unsigned char *cp = pin;
+             table = (const int32_t *)
+               _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
+             weights = (const unsigned char *)
+               _NL_CURRENT (LC_COLLATE, _NL_COLLATE_WEIGHTMB);
+             extra = (const unsigned char *)
+               _NL_CURRENT (LC_COLLATE, _NL_COLLATE_EXTRAMB);
+             indirect = (const int32_t *)
+               _NL_CURRENT (LC_COLLATE, _NL_COLLATE_INDIRECTMB);
+             int32_t idx = findidx (&cp);
+             if (idx > 0)
+               for (i = 0; i < cset->nequiv_classes; ++i)
+                 {
+                   int32_t equiv_class_idx = cset->equiv_classes[i];
+                   size_t weight_len = weights[idx & 0xffffff];
+                   if (weight_len == weights[equiv_class_idx & 0xffffff]
+                       && (idx >> 24) == (equiv_class_idx >> 24))
+                     {
+                       Idx cnt = 0;
+
+                       idx &= 0xffffff;
+                       equiv_class_idx &= 0xffffff;
+
+                       while (cnt <= weight_len
+                              && (weights[equiv_class_idx + 1 + cnt]
+                                  == weights[idx + 1 + cnt]))
+                         ++cnt;
+                       if (cnt > weight_len)
+                         {
+                           match_len = elem_len;
+                           goto check_node_accept_bytes_match;
+                         }
+                     }
+                 }
+           }
+       }
+      else
+# endif /* _LIBC */
+       {
+         /* match with range expression?  */
+#if __GNUC__ >= 2 && ! (__STDC_VERSION__ < 199901L && defined __STRICT_ANSI__)
+         wchar_t cmp_buf[] = {L'\0', L'\0', wc, L'\0', L'\0', L'\0'};
+#else
+         wchar_t cmp_buf[] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
+         cmp_buf[2] = wc;
+#endif
+         for (i = 0; i < cset->nranges; ++i)
+           {
+             cmp_buf[0] = cset->range_starts[i];
+             cmp_buf[4] = cset->range_ends[i];
+             if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
+                 && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
+               {
+                 match_len = char_len;
+                 goto check_node_accept_bytes_match;
+               }
+           }
+       }
+    check_node_accept_bytes_match:
+      if (!cset->non_match)
+       return match_len;
+      else
+       {
+         if (match_len > 0)
+           return 0;
+         else
+           return (elem_len > char_len) ? elem_len : char_len;
+       }
+    }
+  return 0;
+}
+
+# ifdef _LIBC
+static unsigned int
+internal_function
+find_collation_sequence_value (const unsigned char *mbs, size_t mbs_len)
+{
+  uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
+  if (nrules == 0)
+    {
+      if (mbs_len == 1)
+       {
+         /* No valid character.  Match it as a single byte character.  */
+         const unsigned char *collseq = (const unsigned char *)
+           _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
+         return collseq[mbs[0]];
+       }
+      return UINT_MAX;
+    }
+  else
+    {
+      int32_t idx;
+      const unsigned char *extra = (const unsigned char *)
+       _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+      int32_t extrasize = (const unsigned char *)
+       _NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB + 1) - extra;
+
+      for (idx = 0; idx < extrasize;)
+       {
+         int mbs_cnt;
+         bool found = false;
+         int32_t elem_mbs_len;
+         /* Skip the name of collating element name.  */
+         idx = idx + extra[idx] + 1;
+         elem_mbs_len = extra[idx++];
+         if (mbs_len == elem_mbs_len)
+           {
+             for (mbs_cnt = 0; mbs_cnt < elem_mbs_len; ++mbs_cnt)
+               if (extra[idx + mbs_cnt] != mbs[mbs_cnt])
+                 break;
+             if (mbs_cnt == elem_mbs_len)
+               /* Found the entry.  */
+               found = true;
+           }
+         /* Skip the byte sequence of the collating element.  */
+         idx += elem_mbs_len;
+         /* Adjust for the alignment.  */
+         idx = (idx + 3) & ~3;
+         /* Skip the collation sequence value.  */
+         idx += sizeof (uint32_t);
+         /* Skip the wide char sequence of the collating element.  */
+         idx = idx + sizeof (uint32_t) * (extra[idx] + 1);
+         /* If we found the entry, return the sequence value.  */
+         if (found)
+           return *(uint32_t *) (extra + idx);
+         /* Skip the collation sequence value.  */
+         idx += sizeof (uint32_t);
+       }
+      return UINT_MAX;
+    }
+}
+# endif /* _LIBC */
+#endif /* RE_ENABLE_I18N */
+
+/* Check whether the node accepts the byte which is IDX-th
+   byte of the INPUT.  */
+
+static bool
+internal_function
+check_node_accept (const re_match_context_t *mctx, const re_token_t *node,
+                  Idx idx)
+{
+  unsigned char ch;
+  ch = re_string_byte_at (&mctx->input, idx);
+  switch (node->type)
+    {
+    case CHARACTER:
+      if (node->opr.c != ch)
+        return false;
+      break;
+
+    case SIMPLE_BRACKET:
+      if (!bitset_contain (node->opr.sbcset, ch))
+        return false;
+      break;
+
+#ifdef RE_ENABLE_I18N
+    case OP_UTF8_PERIOD:
+      if (ch >= ASCII_CHARS)
+        return false;
+      /* FALLTHROUGH */
+#endif
+    case OP_PERIOD:
+      if ((ch == '\n' && !(mctx->dfa->syntax & RE_DOT_NEWLINE))
+         || (ch == '\0' && (mctx->dfa->syntax & RE_DOT_NOT_NULL)))
+       return false;
+      break;
+
+    default:
+      return false;
+    }
+
+  if (node->constraint)
+    {
+      /* The node has constraints.  Check whether the current context
+        satisfies the constraints.  */
+      unsigned int context = re_string_context_at (&mctx->input, idx,
+                                                  mctx->eflags);
+      if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context))
+       return false;
+    }
+
+  return true;
+}
+
+/* Extend the buffers, if the buffers have run out.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+extend_buffers (re_match_context_t *mctx)
+{
+  reg_errcode_t ret;
+  re_string_t *pstr = &mctx->input;
+
+  /* Avoid overflow.  */
+  if (BE (SIZE_MAX / 2 / sizeof (re_dfastate_t *) <= pstr->bufs_len, 0))
+    return REG_ESPACE;
+
+  /* Double the lengthes of the buffers.  */
+  ret = re_string_realloc_buffers (pstr, pstr->bufs_len * 2);
+  if (BE (ret != REG_NOERROR, 0))
+    return ret;
+
+  if (mctx->state_log != NULL)
+    {
+      /* And double the length of state_log.  */
+      /* XXX We have no indication of the size of this buffer.  If this
+        allocation fail we have no indication that the state_log array
+        does not have the right size.  */
+      re_dfastate_t **new_array = re_realloc (mctx->state_log, re_dfastate_t *,
+                                             pstr->bufs_len + 1);
+      if (BE (new_array == NULL, 0))
+       return REG_ESPACE;
+      mctx->state_log = new_array;
+    }
+
+  /* Then reconstruct the buffers.  */
+  if (pstr->icase)
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+       {
+         ret = build_wcs_upper_buffer (pstr);
+         if (BE (ret != REG_NOERROR, 0))
+           return ret;
+       }
+      else
+#endif /* RE_ENABLE_I18N  */
+       build_upper_buffer (pstr);
+    }
+  else
+    {
+#ifdef RE_ENABLE_I18N
+      if (pstr->mb_cur_max > 1)
+       build_wcs_buffer (pstr);
+      else
+#endif /* RE_ENABLE_I18N  */
+       {
+         if (pstr->trans != NULL)
+           re_string_translate_buffer (pstr);
+       }
+    }
+  return REG_NOERROR;
+}
+
+
+/* Functions for matching context.  */
+
+/* Initialize MCTX.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+match_ctx_init (re_match_context_t *mctx, int eflags, Idx n)
+{
+  mctx->eflags = eflags;
+  mctx->match_last = REG_MISSING;
+  if (n > 0)
+    {
+      /* Avoid overflow.  */
+      size_t max_object_size =
+       MAX (sizeof (struct re_backref_cache_entry),
+            sizeof (re_sub_match_top_t *));
+      if (BE (SIZE_MAX / max_object_size < n, 0))
+       return REG_ESPACE;
+
+      mctx->bkref_ents = re_malloc (struct re_backref_cache_entry, n);
+      mctx->sub_tops = re_malloc (re_sub_match_top_t *, n);
+      if (BE (mctx->bkref_ents == NULL || mctx->sub_tops == NULL, 0))
+       return REG_ESPACE;
+    }
+  /* Already zero-ed by the caller.
+     else
+       mctx->bkref_ents = NULL;
+     mctx->nbkref_ents = 0;
+     mctx->nsub_tops = 0;  */
+  mctx->abkref_ents = n;
+  mctx->max_mb_elem_len = 1;
+  mctx->asub_tops = n;
+  return REG_NOERROR;
+}
+
+/* Clean the entries which depend on the current input in MCTX.
+   This function must be invoked when the matcher changes the start index
+   of the input, or changes the input string.  */
+
+static void
+internal_function
+match_ctx_clean (re_match_context_t *mctx)
+{
+  Idx st_idx;
+  for (st_idx = 0; st_idx < mctx->nsub_tops; ++st_idx)
+    {
+      Idx sl_idx;
+      re_sub_match_top_t *top = mctx->sub_tops[st_idx];
+      for (sl_idx = 0; sl_idx < top->nlasts; ++sl_idx)
+       {
+         re_sub_match_last_t *last = top->lasts[sl_idx];
+         re_free (last->path.array);
+         re_free (last);
+       }
+      re_free (top->lasts);
+      if (top->path)
+       {
+         re_free (top->path->array);
+         re_free (top->path);
+       }
+      free (top);
+    }
+
+  mctx->nsub_tops = 0;
+  mctx->nbkref_ents = 0;
+}
+
+/* Free all the memory associated with MCTX.  */
+
+static void
+internal_function
+match_ctx_free (re_match_context_t *mctx)
+{
+  /* First, free all the memory associated with MCTX->SUB_TOPS.  */
+  match_ctx_clean (mctx);
+  re_free (mctx->sub_tops);
+  re_free (mctx->bkref_ents);
+}
+
+/* Add a new backreference entry to MCTX.
+   Note that we assume that caller never call this function with duplicate
+   entry, and call with STR_IDX which isn't smaller than any existing entry.
+*/
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+match_ctx_add_entry (re_match_context_t *mctx, Idx node, Idx str_idx, Idx from,
+                    Idx to)
+{
+  if (mctx->nbkref_ents >= mctx->abkref_ents)
+    {
+      struct re_backref_cache_entry* new_entry;
+      new_entry = re_realloc (mctx->bkref_ents, struct re_backref_cache_entry,
+                             mctx->abkref_ents * 2);
+      if (BE (new_entry == NULL, 0))
+       {
+         re_free (mctx->bkref_ents);
+         return REG_ESPACE;
+       }
+      mctx->bkref_ents = new_entry;
+      memset (mctx->bkref_ents + mctx->nbkref_ents, '\0',
+             sizeof (struct re_backref_cache_entry) * mctx->abkref_ents);
+      mctx->abkref_ents *= 2;
+    }
+  if (mctx->nbkref_ents > 0
+      && mctx->bkref_ents[mctx->nbkref_ents - 1].str_idx == str_idx)
+    mctx->bkref_ents[mctx->nbkref_ents - 1].more = 1;
+
+  mctx->bkref_ents[mctx->nbkref_ents].node = node;
+  mctx->bkref_ents[mctx->nbkref_ents].str_idx = str_idx;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_from = from;
+  mctx->bkref_ents[mctx->nbkref_ents].subexp_to = to;
+
+  /* This is a cache that saves negative results of check_dst_limits_calc_pos.
+     If bit N is clear, means that this entry won't epsilon-transition to
+     an OP_OPEN_SUBEXP or OP_CLOSE_SUBEXP for the N+1-th subexpression.  If
+     it is set, check_dst_limits_calc_pos_1 will recurse and try to find one
+     such node.
+
+     A backreference does not epsilon-transition unless it is empty, so set
+     to all zeros if FROM != TO.  */
+  mctx->bkref_ents[mctx->nbkref_ents].eps_reachable_subexps_map
+    = (from == to ? -1 : 0);
+
+  mctx->bkref_ents[mctx->nbkref_ents++].more = 0;
+  if (mctx->max_mb_elem_len < to - from)
+    mctx->max_mb_elem_len = to - from;
+  return REG_NOERROR;
+}
+
+/* Return the first entry with the same str_idx, or REG_MISSING if none is
+   found.  Note that MCTX->BKREF_ENTS is already sorted by MCTX->STR_IDX.  */
+
+static Idx
+internal_function
+search_cur_bkref_entry (const re_match_context_t *mctx, Idx str_idx)
+{
+  Idx left, right, mid, last;
+  last = right = mctx->nbkref_ents;
+  for (left = 0; left < right;)
+    {
+      mid = (left + right) / 2;
+      if (mctx->bkref_ents[mid].str_idx < str_idx)
+       left = mid + 1;
+      else
+       right = mid;
+    }
+  if (left < last && mctx->bkref_ents[left].str_idx == str_idx)
+    return left;
+  else
+    return REG_MISSING;
+}
+
+/* Register the node NODE, whose type is OP_OPEN_SUBEXP, and which matches
+   at STR_IDX.  */
+
+static reg_errcode_t
+internal_function __attribute_warn_unused_result__
+match_ctx_add_subtop (re_match_context_t *mctx, Idx node, Idx str_idx)
+{
+#ifdef DEBUG
+  assert (mctx->sub_tops != NULL);
+  assert (mctx->asub_tops > 0);
+#endif
+  if (BE (mctx->nsub_tops == mctx->asub_tops, 0))
+    {
+      Idx new_asub_tops = mctx->asub_tops * 2;
+      re_sub_match_top_t **new_array = re_realloc (mctx->sub_tops,
+                                                  re_sub_match_top_t *,
+                                                  new_asub_tops);
+      if (BE (new_array == NULL, 0))
+       return REG_ESPACE;
+      mctx->sub_tops = new_array;
+      mctx->asub_tops = new_asub_tops;
+    }
+  mctx->sub_tops[mctx->nsub_tops] = calloc (1, sizeof (re_sub_match_top_t));
+  if (BE (mctx->sub_tops[mctx->nsub_tops] == NULL, 0))
+    return REG_ESPACE;
+  mctx->sub_tops[mctx->nsub_tops]->node = node;
+  mctx->sub_tops[mctx->nsub_tops++]->str_idx = str_idx;
+  return REG_NOERROR;
+}
+
+/* Register the node NODE, whose type is OP_CLOSE_SUBEXP, and which matches
+   at STR_IDX, whose corresponding OP_OPEN_SUBEXP is SUB_TOP.  */
+
+static re_sub_match_last_t *
+internal_function
+match_ctx_add_sublast (re_sub_match_top_t *subtop, Idx node, Idx str_idx)
+{
+  re_sub_match_last_t *new_entry;
+  if (BE (subtop->nlasts == subtop->alasts, 0))
+    {
+      Idx new_alasts = 2 * subtop->alasts + 1;
+      re_sub_match_last_t **new_array = re_realloc (subtop->lasts,
+                                                   re_sub_match_last_t *,
+                                                   new_alasts);
+      if (BE (new_array == NULL, 0))
+       return NULL;
+      subtop->lasts = new_array;
+      subtop->alasts = new_alasts;
+    }
+  new_entry = calloc (1, sizeof (re_sub_match_last_t));
+  if (BE (new_entry != NULL, 1))
+    {
+      subtop->lasts[subtop->nlasts] = new_entry;
+      new_entry->node = node;
+      new_entry->str_idx = str_idx;
+      ++subtop->nlasts;
+    }
+  return new_entry;
+}
+
+static void
+internal_function
+sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts,
+              re_dfastate_t **limited_sts, Idx last_node, Idx last_str_idx)
+{
+  sctx->sifted_states = sifted_sts;
+  sctx->limited_states = limited_sts;
+  sctx->last_node = last_node;
+  sctx->last_str_idx = last_str_idx;
+  re_node_set_init_empty (&sctx->limits);
+}
diff --git a/lib/strcasecmp.c b/lib/strcasecmp.c
new file mode 100644
index 0000000..1ed5175
--- /dev/null
+++ b/lib/strcasecmp.c
@@ -0,0 +1,63 @@
+/* Case-insensitive string comparison function.
+   Copyright (C) 1998-1999, 2005-2007, 2009-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <string.h>
+
+#include <ctype.h>
+#include <limits.h>
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less than, equal to or greater
+   than S2.
+   Note: This function does not work with multibyte strings!  */
+
+int
+strcasecmp (const char *s1, const char *s2)
+{
+  const unsigned char *p1 = (const unsigned char *) s1;
+  const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+
+  if (p1 == p2)
+    return 0;
+
+  do
+    {
+      c1 = TOLOWER (*p1);
+      c2 = TOLOWER (*p2);
+
+      if (c1 == '\0')
+        break;
+
+      ++p1;
+      ++p2;
+    }
+  while (c1 == c2);
+
+  if (UCHAR_MAX <= INT_MAX)
+    return c1 - c2;
+  else
+    /* On machines where 'char' and 'int' are types of the same size, the
+       difference of two 'unsigned char' values - including the sign bit -
+       doesn't fit in an 'int'.  */
+    return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
+}
diff --git a/lib/streq.h b/lib/streq.h
new file mode 100644
index 0000000..b649411
--- /dev/null
+++ b/lib/streq.h
@@ -0,0 +1,176 @@
+/* Optimized string comparison.
+   Copyright (C) 2001-2002, 2007, 2009-2012 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Lesser General Public License as published
+   by the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible <address@hidden>.  */
+
+#ifndef _GL_STREQ_H
+#define _GL_STREQ_H
+
+#include <string.h>
+
+/* STREQ allows to optimize string comparison with a small literal string.
+     STREQ (s, "EUC-KR", 'E', 'U', 'C', '-', 'K', 'R', 0, 0, 0)
+   is semantically equivalent to
+     strcmp (s, "EUC-KR") == 0
+   just faster.  */
+
+/* Help GCC to generate good code for string comparisons with
+   immediate strings. */
+#if defined (__GNUC__) && defined (__OPTIMIZE__)
+
+static inline int
+streq9 (const char *s1, const char *s2)
+{
+  return strcmp (s1 + 9, s2 + 9) == 0;
+}
+
+static inline int
+streq8 (const char *s1, const char *s2, char s28)
+{
+  if (s1[8] == s28)
+    {
+      if (s28 == 0)
+        return 1;
+      else
+        return streq9 (s1, s2);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq7 (const char *s1, const char *s2, char s27, char s28)
+{
+  if (s1[7] == s27)
+    {
+      if (s27 == 0)
+        return 1;
+      else
+        return streq8 (s1, s2, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq6 (const char *s1, const char *s2, char s26, char s27, char s28)
+{
+  if (s1[6] == s26)
+    {
+      if (s26 == 0)
+        return 1;
+      else
+        return streq7 (s1, s2, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq5 (const char *s1, const char *s2, char s25, char s26, char s27, char s28)
+{
+  if (s1[5] == s25)
+    {
+      if (s25 == 0)
+        return 1;
+      else
+        return streq6 (s1, s2, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq4 (const char *s1, const char *s2, char s24, char s25, char s26, char 
s27, char s28)
+{
+  if (s1[4] == s24)
+    {
+      if (s24 == 0)
+        return 1;
+      else
+        return streq5 (s1, s2, s25, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq3 (const char *s1, const char *s2, char s23, char s24, char s25, char 
s26, char s27, char s28)
+{
+  if (s1[3] == s23)
+    {
+      if (s23 == 0)
+        return 1;
+      else
+        return streq4 (s1, s2, s24, s25, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq2 (const char *s1, const char *s2, char s22, char s23, char s24, char 
s25, char s26, char s27, char s28)
+{
+  if (s1[2] == s22)
+    {
+      if (s22 == 0)
+        return 1;
+      else
+        return streq3 (s1, s2, s23, s24, s25, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq1 (const char *s1, const char *s2, char s21, char s22, char s23, char 
s24, char s25, char s26, char s27, char s28)
+{
+  if (s1[1] == s21)
+    {
+      if (s21 == 0)
+        return 1;
+      else
+        return streq2 (s1, s2, s22, s23, s24, s25, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+static inline int
+streq0 (const char *s1, const char *s2, char s20, char s21, char s22, char 
s23, char s24, char s25, char s26, char s27, char s28)
+{
+  if (s1[0] == s20)
+    {
+      if (s20 == 0)
+        return 1;
+      else
+        return streq1 (s1, s2, s21, s22, s23, s24, s25, s26, s27, s28);
+    }
+  else
+    return 0;
+}
+
+#define STREQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
+  streq0 (s1, s2, s20, s21, s22, s23, s24, s25, s26, s27, s28)
+
+#else
+
+#define STREQ(s1,s2,s20,s21,s22,s23,s24,s25,s26,s27,s28) \
+  (strcmp (s1, s2) == 0)
+
+#endif
+
+#endif /* _GL_STREQ_H */
diff --git a/lib/strings.in.h b/lib/strings.in.h
new file mode 100644
index 0000000..fc60919
--- /dev/null
+++ b/lib/strings.in.h
@@ -0,0 +1,123 @@
+/* A substitute <strings.h>.
+
+   Copyright (C) 2007-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef address@hidden@_STRINGS_H
+
+#if __GNUC__ >= 3
address@hidden@
+#endif
address@hidden@
+
+/* Minix 3.1.8 has a bug: <sys/types.h> must be included before <strings.h>.
+   But avoid namespace pollution on glibc systems.  */
+#if defined __minix && !defined __GLIBC__
+# include <sys/types.h>
+#endif
+
+/* The include_next requires a split double-inclusion guard.  */
+#if @HAVE_STRINGS_H@
+# @INCLUDE_NEXT@ @NEXT_STRINGS_H@
+#endif
+
+#ifndef address@hidden@_STRINGS_H
+#define address@hidden@_STRINGS_H
+
+#if ! @HAVE_DECL_STRNCASECMP@
+/* Get size_t.  */
+# include <stddef.h>
+#endif
+
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_ARG_NONNULL is copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+  /* Find the index of the least-significant set bit.  */
+#if @GNULIB_FFS@
+# if address@hidden@
+_GL_FUNCDECL_SYS (ffs, int, (int i));
+# endif
+_GL_CXXALIAS_SYS (ffs, int, (int i));
+_GL_CXXALIASWARN (ffs);
+#elif defined GNULIB_POSIXCHECK
+# undef ffs
+# if HAVE_RAW_DECL_FFS
+_GL_WARN_ON_USE (ffs, "ffs is not portable - use the ffs module");
+# endif
+#endif
+
+/* Compare strings S1 and S2, ignoring case, returning less than, equal to or
+   greater than zero if S1 is lexicographically less than, equal to or greater
+   than S2.
+   Note: This function does not work in multibyte locales.  */
+#if ! @HAVE_STRCASECMP@
+extern int strcasecmp (char const *s1, char const *s2)
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+#if defined GNULIB_POSIXCHECK
+/* strcasecmp() does not work with multibyte strings:
+   POSIX says that it operates on "strings", and "string" in POSIX is defined
+   as a sequence of bytes, not of characters.   */
+# undef strcasecmp
+# if HAVE_RAW_DECL_STRCASECMP
+_GL_WARN_ON_USE (strcasecmp, "strcasecmp cannot work correctly on character "
+                 "strings in multibyte locales - "
+                 "use mbscasecmp if you care about "
+                 "internationalization, or use c_strcasecmp , "
+                 "gnulib module c-strcase) if you want a locale "
+                 "independent function");
+# endif
+#endif
+
+/* Compare no more than N bytes of strings S1 and S2, ignoring case,
+   returning less than, equal to or greater than zero if S1 is
+   lexicographically less than, equal to or greater than S2.
+   Note: This function cannot work correctly in multibyte locales.  */
+#if ! @HAVE_DECL_STRNCASECMP@
+extern int strncasecmp (char const *s1, char const *s2, size_t n)
+     _GL_ARG_NONNULL ((1, 2));
+#endif
+#if defined GNULIB_POSIXCHECK
+/* strncasecmp() does not work with multibyte strings:
+   POSIX says that it operates on "strings", and "string" in POSIX is defined
+   as a sequence of bytes, not of characters.  */
+# undef strncasecmp
+# if HAVE_RAW_DECL_STRNCASECMP
+_GL_WARN_ON_USE (strncasecmp, "strncasecmp cannot work correctly on character "
+                 "strings in multibyte locales - "
+                 "use mbsncasecmp or mbspcasecmp if you care about "
+                 "internationalization, or use c_strncasecmp , "
+                 "gnulib module c-strcase) if you want a locale "
+                 "independent function");
+# endif
+#endif
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* address@hidden@_STRING_H */
+#endif /* address@hidden@_STRING_H */
diff --git a/lib/strncasecmp.c b/lib/strncasecmp.c
new file mode 100644
index 0000000..d330ff6
--- /dev/null
+++ b/lib/strncasecmp.c
@@ -0,0 +1,63 @@
+/* strncasecmp.c -- case insensitive string comparator
+   Copyright (C) 1998-1999, 2005-2007, 2009-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <string.h>
+
+#include <ctype.h>
+#include <limits.h>
+
+#define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
+
+/* Compare no more than N bytes of strings S1 and S2, ignoring case,
+   returning less than, equal to or greater than zero if S1 is
+   lexicographically less than, equal to or greater than S2.
+   Note: This function cannot work correctly in multibyte locales.  */
+
+int
+strncasecmp (const char *s1, const char *s2, size_t n)
+{
+  register const unsigned char *p1 = (const unsigned char *) s1;
+  register const unsigned char *p2 = (const unsigned char *) s2;
+  unsigned char c1, c2;
+
+  if (p1 == p2 || n == 0)
+    return 0;
+
+  do
+    {
+      c1 = TOLOWER (*p1);
+      c2 = TOLOWER (*p2);
+
+      if (--n == 0 || c1 == '\0')
+        break;
+
+      ++p1;
+      ++p2;
+    }
+  while (c1 == c2);
+
+  if (UCHAR_MAX <= INT_MAX)
+    return c1 - c2;
+  else
+    /* On machines where 'char' and 'int' are types of the same size, the
+       difference of two 'unsigned char' values - including the sign bit -
+       doesn't fit in an 'int'.  */
+    return (c1 > c2 ? 1 : c1 < c2 ? -1 : 0);
+}
diff --git a/lib/wcrtomb.c b/lib/wcrtomb.c
new file mode 100644
index 0000000..a4d6bcd
--- /dev/null
+++ b/lib/wcrtomb.c
@@ -0,0 +1,53 @@
+/* Convert wide character to multibyte character.
+   Copyright (C) 2008-2012 Free Software Foundation, Inc.
+   Written by Bruno Haible <address@hidden>, 2008.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <wchar.h>
+
+#include <errno.h>
+#include <stdlib.h>
+
+
+size_t
+wcrtomb (char *s, wchar_t wc, mbstate_t *ps)
+{
+  /* This implementation of wcrtomb on top of wctomb() supports only
+     stateless encodings.  ps must be in the initial state.  */
+  if (ps != NULL && !mbsinit (ps))
+    {
+      errno = EINVAL;
+      return (size_t)(-1);
+    }
+
+  if (s == NULL)
+    /* We know the NUL wide character corresponds to the NUL character.  */
+    return 1;
+  else
+    {
+      int ret = wctomb (s, wc);
+
+      if (ret >= 0)
+        return ret;
+      else
+        {
+          errno = EILSEQ;
+          return (size_t)(-1);
+        }
+    }
+}
diff --git a/lib/wctype.in.h b/lib/wctype.in.h
new file mode 100644
index 0000000..f25ad30
--- /dev/null
+++ b/lib/wctype.in.h
@@ -0,0 +1,499 @@
+/* A substitute for ISO C99 <wctype.h>, for platforms that lack it.
+
+   Copyright (C) 2006-2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Bruno Haible and Paul Eggert.  */
+
+/*
+ * ISO C 99 <wctype.h> for platforms that lack it.
+ * <http://www.opengroup.org/susv3xbd/wctype.h.html>
+ *
+ * iswctype, towctrans, towlower, towupper, wctrans, wctype,
+ * wctrans_t, and wctype_t are not yet implemented.
+ */
+
+#ifndef address@hidden@_WCTYPE_H
+
+#if __GNUC__ >= 3
address@hidden@
+#endif
address@hidden@
+
+#if @HAVE_WINT_T@
+/* Solaris 2.5 has a bug: <wchar.h> must be included before <wctype.h>.
+   Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+# include <stddef.h>
+# include <stdio.h>
+# include <time.h>
+# include <wchar.h>
+#endif
+
+/* Include the original <wctype.h> if it exists.
+   BeOS 5 has the functions but no <wctype.h>.  */
+/* The include_next requires a split double-inclusion guard.  */
+#if @HAVE_WCTYPE_H@
+# @INCLUDE_NEXT@ @NEXT_WCTYPE_H@
+#endif
+
+#ifndef address@hidden@_WCTYPE_H
+#define address@hidden@_WCTYPE_H
+
+/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */
+
+/* The definition of _GL_WARN_ON_USE is copied here.  */
+
+/* Solaris 2.6 <wctype.h> includes <widec.h> which includes <euc.h> which
+   #defines a number of identifiers in the application namespace.  Revert
+   these #defines.  */
+#ifdef __sun
+# undef multibyte
+# undef eucw1
+# undef eucw2
+# undef eucw3
+# undef scrw1
+# undef scrw2
+# undef scrw3
+#endif
+
+/* Define wint_t and WEOF.  (Also done in wchar.in.h.)  */
+#if address@hidden@ && !defined wint_t
+# define wint_t int
+# ifndef WEOF
+#  define WEOF -1
+# endif
+#else
+/* MSVC defines wint_t as 'unsigned short' in <crtdefs.h>.
+   This is too small: ISO C 99 section 7.24.1.(2) says that wint_t must be
+   "unchanged by default argument promotions".  Override it.  */
+# if defined _MSC_VER
+#  if !GNULIB_defined_wint_t
+#   include <crtdefs.h>
+typedef unsigned int rpl_wint_t;
+#   undef wint_t
+#   define wint_t rpl_wint_t
+#   define GNULIB_defined_wint_t 1
+#  endif
+# endif
+# ifndef WEOF
+#  define WEOF ((wint_t) -1)
+# endif
+#endif
+
+
+#if !GNULIB_defined_wctype_functions
+
+/* FreeBSD 4.4 to 4.11 has <wctype.h> but lacks the functions.
+   Linux libc5 has <wctype.h> and the functions but they are broken.
+   Assume all 11 functions (all isw* except iswblank) are implemented the
+   same way, or not at all.  */
+# if ! @HAVE_ISWCNTRL@ || @REPLACE_ISWCNTRL@
+
+/* IRIX 5.3 has macros but no functions, its isw* macros refer to an
+   undefined variable _ctmp_ and to <ctype.h> macros like _P, and they
+   refer to system functions like _iswctype that are not in the
+   standard C library.  Rather than try to get ancient buggy
+   implementations like this to work, just disable them.  */
+#  undef iswalnum
+#  undef iswalpha
+#  undef iswblank
+#  undef iswcntrl
+#  undef iswdigit
+#  undef iswgraph
+#  undef iswlower
+#  undef iswprint
+#  undef iswpunct
+#  undef iswspace
+#  undef iswupper
+#  undef iswxdigit
+#  undef towlower
+#  undef towupper
+
+/* Linux libc5 has <wctype.h> and the functions but they are broken.  */
+#  if @REPLACE_ISWCNTRL@
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    define iswalnum rpl_iswalnum
+#    define iswalpha rpl_iswalpha
+#    define iswblank rpl_iswblank
+#    define iswcntrl rpl_iswcntrl
+#    define iswdigit rpl_iswdigit
+#    define iswgraph rpl_iswgraph
+#    define iswlower rpl_iswlower
+#    define iswprint rpl_iswprint
+#    define iswpunct rpl_iswpunct
+#    define iswspace rpl_iswspace
+#    define iswupper rpl_iswupper
+#    define iswxdigit rpl_iswxdigit
+#   endif
+#  endif
+#  if @REPLACE_TOWLOWER@
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    define towlower rpl_towlower
+#    define towupper rpl_towupper
+#   endif
+#  endif
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswalnum
+#  else
+iswalnum
+#  endif
+         (wint_t wc)
+{
+  return ((wc >= '0' && wc <= '9')
+          || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z'));
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswalpha
+#  else
+iswalpha
+#  endif
+         (wint_t wc)
+{
+  return (wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswblank
+#  else
+iswblank
+#  endif
+         (wint_t wc)
+{
+  return wc == ' ' || wc == '\t';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswcntrl
+#  else
+iswcntrl
+#  endif
+        (wint_t wc)
+{
+  return (wc & ~0x1f) == 0 || wc == 0x7f;
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswdigit
+#  else
+iswdigit
+#  endif
+         (wint_t wc)
+{
+  return wc >= '0' && wc <= '9';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswgraph
+#  else
+iswgraph
+#  endif
+         (wint_t wc)
+{
+  return wc >= '!' && wc <= '~';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswlower
+#  else
+iswlower
+#  endif
+         (wint_t wc)
+{
+  return wc >= 'a' && wc <= 'z';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswprint
+#  else
+iswprint
+#  endif
+         (wint_t wc)
+{
+  return wc >= ' ' && wc <= '~';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswpunct
+#  else
+iswpunct
+#  endif
+         (wint_t wc)
+{
+  return (wc >= '!' && wc <= '~'
+          && !((wc >= '0' && wc <= '9')
+               || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'Z')));
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswspace
+#  else
+iswspace
+#  endif
+         (wint_t wc)
+{
+  return (wc == ' ' || wc == '\t'
+          || wc == '\n' || wc == '\v' || wc == '\f' || wc == '\r');
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswupper
+#  else
+iswupper
+#  endif
+         (wint_t wc)
+{
+  return wc >= 'A' && wc <= 'Z';
+}
+
+static inline int
+#  if @REPLACE_ISWCNTRL@
+rpl_iswxdigit
+#  else
+iswxdigit
+#  endif
+          (wint_t wc)
+{
+  return ((wc >= '0' && wc <= '9')
+          || ((wc & ~0x20) >= 'A' && (wc & ~0x20) <= 'F'));
+}
+
+static inline wint_t
+#  if @REPLACE_TOWLOWER@
+rpl_towlower
+#  else
+towlower
+#  endif
+         (wint_t wc)
+{
+  return (wc >= 'A' && wc <= 'Z' ? wc - 'A' + 'a' : wc);
+}
+
+static inline wint_t
+#  if @REPLACE_TOWLOWER@
+rpl_towupper
+#  else
+towupper
+#  endif
+         (wint_t wc)
+{
+  return (wc >= 'a' && wc <= 'z' ? wc - 'a' + 'A' : wc);
+}
+
+# elif @GNULIB_ISWBLANK@ && (! @HAVE_ISWBLANK@ || @REPLACE_ISWBLANK@)
+/* Only the iswblank function is missing.  */
+
+#  if @REPLACE_ISWBLANK@
+#   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#    define iswblank rpl_iswblank
+#   endif
+_GL_FUNCDECL_RPL (iswblank, int, (wint_t wc));
+#  else
+_GL_FUNCDECL_SYS (iswblank, int, (wint_t wc));
+#  endif
+
+# endif
+
+# if defined __MINGW32__
+
+/* On native Windows, wchar_t is uint16_t, and wint_t is uint32_t.
+   The functions towlower and towupper are implemented in the MSVCRT library
+   to take a wchar_t argument and return a wchar_t result.  mingw declares
+   these functions to take a wint_t argument and return a wint_t result.
+   This means that:
+   1. When the user passes an argument outside the range 0x0000..0xFFFF, the
+      function will look only at the lower 16 bits.  This is allowed according
+      to POSIX.
+   2. The return value is returned in the lower 16 bits of the result register.
+      The upper 16 bits are random: whatever happened to be in that part of the
+      result register.  We need to fix this by adding a zero-extend from
+      wchar_t to wint_t after the call.  */
+
+static inline wint_t
+rpl_towlower (wint_t wc)
+{
+  return (wint_t) (wchar_t) towlower (wc);
+}
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define towlower rpl_towlower
+#  endif
+
+static inline wint_t
+rpl_towupper (wint_t wc)
+{
+  return (wint_t) (wchar_t) towupper (wc);
+}
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   define towupper rpl_towupper
+#  endif
+
+# endif /* __MINGW32__ */
+
+# define GNULIB_defined_wctype_functions 1
+#endif
+
+#if @REPLACE_ISWCNTRL@
+_GL_CXXALIAS_RPL (iswalnum, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswalpha, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswcntrl, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswdigit, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswgraph, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswlower, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswprint, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswpunct, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswspace, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswupper, int, (wint_t wc));
+_GL_CXXALIAS_RPL (iswxdigit, int, (wint_t wc));
+#else
+_GL_CXXALIAS_SYS (iswalnum, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswalpha, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswcntrl, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswdigit, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswgraph, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswlower, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswprint, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswpunct, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswspace, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswupper, int, (wint_t wc));
+_GL_CXXALIAS_SYS (iswxdigit, int, (wint_t wc));
+#endif
+_GL_CXXALIASWARN (iswalnum);
+_GL_CXXALIASWARN (iswalpha);
+_GL_CXXALIASWARN (iswcntrl);
+_GL_CXXALIASWARN (iswdigit);
+_GL_CXXALIASWARN (iswgraph);
+_GL_CXXALIASWARN (iswlower);
+_GL_CXXALIASWARN (iswprint);
+_GL_CXXALIASWARN (iswpunct);
+_GL_CXXALIASWARN (iswspace);
+_GL_CXXALIASWARN (iswupper);
+_GL_CXXALIASWARN (iswxdigit);
+
+#if @GNULIB_ISWBLANK@
+# if @REPLACE_ISWCNTRL@ || @REPLACE_ISWBLANK@
+_GL_CXXALIAS_RPL (iswblank, int, (wint_t wc));
+# else
+_GL_CXXALIAS_SYS (iswblank, int, (wint_t wc));
+# endif
+_GL_CXXALIASWARN (iswblank);
+#endif
+
+#if address@hidden@
+# if !GNULIB_defined_wctype_t
+typedef void * wctype_t;
+#  define GNULIB_defined_wctype_t 1
+# endif
+#endif
+
+/* Get a descriptor for a wide character property.  */
+#if @GNULIB_WCTYPE@
+# if address@hidden@
+_GL_FUNCDECL_SYS (wctype, wctype_t, (const char *name));
+# endif
+_GL_CXXALIAS_SYS (wctype, wctype_t, (const char *name));
+_GL_CXXALIASWARN (wctype);
+#elif defined GNULIB_POSIXCHECK
+# undef wctype
+# if HAVE_RAW_DECL_WCTYPE
+_GL_WARN_ON_USE (wctype, "wctype is unportable - "
+                 "use gnulib module wctype for portability");
+# endif
+#endif
+
+/* Test whether a wide character has a given property.
+   The argument WC must be either a wchar_t value or WEOF.
+   The argument DESC must have been returned by the wctype() function.  */
+#if @GNULIB_ISWCTYPE@
+# if address@hidden@
+_GL_FUNCDECL_SYS (iswctype, int, (wint_t wc, wctype_t desc));
+# endif
+_GL_CXXALIAS_SYS (iswctype, int, (wint_t wc, wctype_t desc));
+_GL_CXXALIASWARN (iswctype);
+#elif defined GNULIB_POSIXCHECK
+# undef iswctype
+# if HAVE_RAW_DECL_ISWCTYPE
+_GL_WARN_ON_USE (iswctype, "iswctype is unportable - "
+                 "use gnulib module iswctype for portability");
+# endif
+#endif
+
+#if @REPLACE_TOWLOWER@ || defined __MINGW32__
+_GL_CXXALIAS_RPL (towlower, wint_t, (wint_t wc));
+_GL_CXXALIAS_RPL (towupper, wint_t, (wint_t wc));
+#else
+_GL_CXXALIAS_SYS (towlower, wint_t, (wint_t wc));
+_GL_CXXALIAS_SYS (towupper, wint_t, (wint_t wc));
+#endif
+_GL_CXXALIASWARN (towlower);
+_GL_CXXALIASWARN (towupper);
+
+#if address@hidden@
+# if !GNULIB_defined_wctrans_t
+typedef void * wctrans_t;
+#  define GNULIB_defined_wctrans_t 1
+# endif
+#endif
+
+/* Get a descriptor for a wide character case conversion.  */
+#if @GNULIB_WCTRANS@
+# if address@hidden@
+_GL_FUNCDECL_SYS (wctrans, wctrans_t, (const char *name));
+# endif
+_GL_CXXALIAS_SYS (wctrans, wctrans_t, (const char *name));
+_GL_CXXALIASWARN (wctrans);
+#elif defined GNULIB_POSIXCHECK
+# undef wctrans
+# if HAVE_RAW_DECL_WCTRANS
+_GL_WARN_ON_USE (wctrans, "wctrans is unportable - "
+                 "use gnulib module wctrans for portability");
+# endif
+#endif
+
+/* Perform a given case conversion on a wide character.
+   The argument WC must be either a wchar_t value or WEOF.
+   The argument DESC must have been returned by the wctrans() function.  */
+#if @GNULIB_TOWCTRANS@
+# if address@hidden@
+_GL_FUNCDECL_SYS (towctrans, wint_t, (wint_t wc, wctrans_t desc));
+# endif
+_GL_CXXALIAS_SYS (towctrans, wint_t, (wint_t wc, wctrans_t desc));
+_GL_CXXALIASWARN (towctrans);
+#elif defined GNULIB_POSIXCHECK
+# undef towctrans
+# if HAVE_RAW_DECL_TOWCTRANS
+_GL_WARN_ON_USE (towctrans, "towctrans is unportable - "
+                 "use gnulib module towctrans for portability");
+# endif
+#endif
+
+
+#endif /* address@hidden@_WCTYPE_H */
+#endif /* address@hidden@_WCTYPE_H */
diff --git a/libguile/init.c b/libguile/init.c
index 633f8c6..f171950 100644
--- a/libguile/init.c
+++ b/libguile/init.c
@@ -1,5 +1,6 @@
-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2004, 2006, 
2009, 2010, 2011 Free Software Foundation, Inc.
- * 
+/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
+ *   2004, 2006, 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either version 3 of
@@ -91,7 +92,7 @@
 #include "libguile/poll.h"
 #include "libguile/ports.h"
 #include "libguile/posix.h"
-#ifdef HAVE_REGCOMP
+#ifdef ENABLE_REGEX
 #include "libguile/regex-posix.h"
 #endif
 #include "libguile/print.h"
@@ -453,7 +454,7 @@ scm_i_init_guile (void *base)
 #ifdef HAVE_POSIX
   scm_init_posix ();
 #endif
-#ifdef HAVE_REGCOMP
+#ifdef ENABLE_REGEX
   scm_init_regex_posix (); /* Requires smob_prehistory */
 #endif
   scm_init_procs ();
diff --git a/libguile/net_db.c b/libguile/net_db.c
index 61dd2f3..4d63aab 100644
--- a/libguile/net_db.c
+++ b/libguile/net_db.c
@@ -1,6 +1,7 @@
 /* "net_db.c" network database support
- * Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2006, 2009, 2010, 2011 
Free Software Foundation, Inc.
- * 
+ * Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2006, 2009,
+ *   2010, 2011, 2012 Free Software Foundation, Inc.
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either version 3 of
@@ -590,10 +591,14 @@ SCM_DEFINE (scm_getaddrinfo, "getaddrinfo", 1, 5, 0,
            "@item EAI_NONAME\n"
            "Either @var{name} does not resolve for the supplied parameters, "
            "or neither @var{name} nor @var{service} were supplied.\n\n"
+
+           /* See `sysdeps/posix/getaddrinfo.c' in the GNU libc, and
+              
<http://www.opensource.apple.com/source/Libinfo/Libinfo-324.1/lookup.subproj/netdb.h>,
+              for details on EAI_NODATA.  */
            "@item EAI_NODATA\n"
-           "This non-POSIX error code can be returned on GNU systems when a\n"
-           "request was actually made but returned no data, meaning\n"
-           "that no address is associated with @var{name}.  Error handling\n"
+           "This non-POSIX error code can be returned on some systems (GNU "
+           "and Darwin, at least), for example when @var{name} is known "
+           "but requests that were made turned out no data.  Error handling\n"
            "code should be prepared to handle it when it is defined.\n\n"
            "@item EAI_SERVICE\n"
            "@var{service} was not recognized for the specified socket 
type.\n\n"
diff --git a/libguile/regex-posix.c b/libguile/regex-posix.c
index 3423099..bec0f89 100644
--- a/libguile/regex-posix.c
+++ b/libguile/regex-posix.c
@@ -1,4 +1,4 @@
-/*     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2006, 2007, 2010, 
2011 Free Software Foundation, Inc.
+/*     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2004, 2006, 2007, 2010, 
2011, 2012 Free Software Foundation, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
@@ -35,23 +35,7 @@
 
 #include "libguile/_scm.h"
 
-/* Supposedly, this file is never compiled unless we know we have
-   POSIX regular expressions.  But we still put this in an #ifdef so
-   the file is CPP'able (for dependency scanning) even on systems that
-   don't have a <regex.h> header.  */
-#ifdef HAVE_REGCOMP
-#ifdef HAVE_REGEX_H
 #include <regex.h>
-#else
-#ifdef HAVE_RXPOSIX_H
-#include <rxposix.h>           /* GNU Rx library */
-#else
-#ifdef HAVE_RX_RXPOSIX_H
-#include <rx/rxposix.h>                /* GNU Rx library on Linux */
-#endif
-#endif
-#endif
-#endif
 
 #ifdef HAVE_WCHAR_H
 #include <wchar.h>
diff --git a/m4/btowc.m4 b/m4/btowc.m4
new file mode 100644
index 0000000..e565321
--- /dev/null
+++ b/m4/btowc.m4
@@ -0,0 +1,116 @@
+# btowc.m4 serial 10
+dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_BTOWC],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+
+  dnl Check whether <wchar.h> is usable at all, first. Otherwise the test
+  dnl program below may lead to an endless loop. See
+  dnl <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42440>.
+  AC_REQUIRE([gl_WCHAR_H_INLINE_OK])
+
+  AC_CHECK_FUNCS_ONCE([btowc])
+  if test $ac_cv_func_btowc = no; then
+    HAVE_BTOWC=0
+  else
+
+    AC_REQUIRE([AC_PROG_CC])
+    AC_REQUIRE([gt_LOCALE_FR])
+    AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+    dnl Cygwin 1.7.2 btowc('\0') is WEOF, not 0.
+    AC_CACHE_CHECK([whether btowc(0) is correct],
+      [gl_cv_func_btowc_nul],
+      [
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  if (btowc ('\0') != 0)
+    return 1;
+  return 0;
+}]])],
+          [gl_cv_func_btowc_nul=yes],
+          [gl_cv_func_btowc_nul=no],
+          [
+changequote(,)dnl
+           case "$host_os" in
+                      # Guess no on Cygwin.
+             cygwin*) gl_cv_func_btowc_nul="guessing no" ;;
+                      # Guess yes otherwise.
+             *)       gl_cv_func_btowc_nul="guessing yes" ;;
+           esac
+changequote([,])dnl
+          ])
+      ])
+
+    dnl IRIX 6.5 btowc(EOF) is 0xFF, not WEOF.
+    AC_CACHE_CHECK([whether btowc(EOF) is correct],
+      [gl_cv_func_btowc_eof],
+      [
+        dnl Initial guess, used when cross-compiling or when no suitable locale
+        dnl is present.
+changequote(,)dnl
+        case "$host_os" in
+                 # Guess no on IRIX.
+          irix*) gl_cv_func_btowc_eof="guessing no" ;;
+                 # Guess yes otherwise.
+          *)     gl_cv_func_btowc_eof="guessing yes" ;;
+        esac
+changequote([,])dnl
+        if test $LOCALE_FR != none; then
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
+    {
+      if (btowc (EOF) != WEOF)
+        return 1;
+    }
+  return 0;
+}]])],
+            [gl_cv_func_btowc_eof=yes],
+            [gl_cv_func_btowc_eof=no],
+            [:])
+        fi
+      ])
+
+    case "$gl_cv_func_btowc_nul" in
+      *yes) ;;
+      *) REPLACE_BTOWC=1 ;;
+    esac
+    case "$gl_cv_func_btowc_eof" in
+      *yes) ;;
+      *) REPLACE_BTOWC=1 ;;
+    esac
+  fi
+])
+
+# Prerequisites of lib/btowc.c.
+AC_DEFUN([gl_PREREQ_BTOWC], [
+  :
+])
diff --git a/m4/gnulib-cache.m4 b/m4/gnulib-cache.m4
index 5aa46ab..4ab00dd 100644
--- a/m4/gnulib-cache.m4
+++ b/m4/gnulib-cache.m4
@@ -27,7 +27,7 @@
 
 
 # Specification in the form of a command-line invocation:
-#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu 
--source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests 
--aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool 
--macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen 
autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale 
environ extensions flock floor fpieee frexp full-read full-write func gendocs 
getaddrinfo getpeername getsockname getsockopt git-version-gen 
gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf 
inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility 
libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu 
malloca nproc open pipe2 putenv recv recvfrom rename send sendto setenv 
setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat 
trunc verify vsnprintf warnings wchar
+#   gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu 
--source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests 
--aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool 
--macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen 
autobuild bind byteswap canonicalize-lgpl ceil close connect dirfd duplocale 
environ extensions flock floor fpieee frexp full-read full-write func gendocs 
getaddrinfo getpeername getsockname getsockopt git-version-gen 
gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf 
inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility 
libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu 
malloca nproc open pipe2 putenv recv recvfrom regex rename send sendto setenv 
setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat 
trunc verify vsnprintf warnings wchar
 
 # Specification in the form of a few gnulib-tool.m4 macro invocations:
 gl_LOCAL_DIR([gnulib-local])
@@ -86,6 +86,7 @@ gl_MODULES([
   putenv
   recv
   recvfrom
+  regex
   rename
   send
   sendto
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index 9ec19f0..498c5fa 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -48,6 +48,7 @@ AC_DEFUN([gl_EARLY],
   AB_INIT
   # Code from module binary-io:
   # Code from module bind:
+  # Code from module btowc:
   # Code from module byteswap:
   # Code from module c-ctype:
   # Code from module c-strcase:
@@ -108,6 +109,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module isnand-nolibm:
   # Code from module isnanf:
   # Code from module isnanl:
+  # Code from module langinfo:
   # Code from module largefile:
   AC_REQUIRE([AC_SYS_LARGEFILE])
   # Code from module ldexp:
@@ -124,12 +126,16 @@ AC_DEFUN([gl_EARLY],
   # Code from module malloc-posix:
   # Code from module malloca:
   # Code from module math:
+  # Code from module mbrtowc:
+  # Code from module mbsinit:
+  # Code from module mbtowc:
   # Code from module memchr:
   # Code from module msvc-inval:
   # Code from module msvc-nothrow:
   # Code from module multiarch:
   # Code from module netdb:
   # Code from module netinet_in:
+  # Code from module nl_langinfo:
   # Code from module nocrash:
   # Code from module nproc:
   # Code from module open:
@@ -141,6 +147,7 @@ AC_DEFUN([gl_EARLY],
   # Code from module readlink:
   # Code from module recv:
   # Code from module recvfrom:
+  # Code from module regex:
   # Code from module rename:
   # Code from module rmdir:
   # Code from module safe-read:
@@ -173,9 +180,12 @@ AC_DEFUN([gl_EARLY],
   # Code from module stdint:
   # Code from module stdio:
   # Code from module stdlib:
+  # Code from module strcase:
+  # Code from module streq:
   # Code from module strftime:
   # Code from module striconveh:
   # Code from module string:
+  # Code from module strings:
   # Code from module sys_file:
   # Code from module sys_socket:
   # Code from module sys_stat:
@@ -200,6 +210,8 @@ AC_DEFUN([gl_EARLY],
   # Code from module vsnprintf:
   # Code from module warnings:
   # Code from module wchar:
+  # Code from module wcrtomb:
+  # Code from module wctype-h:
   # Code from module write:
   # Code from module xsize:
 ])
@@ -231,6 +243,12 @@ if test "$ac_cv_header_winsock2_h" = yes; then
   AC_LIBOBJ([bind])
 fi
 gl_SYS_SOCKET_MODULE_INDICATOR([bind])
+gl_FUNC_BTOWC
+if test $HAVE_BTOWC = 0 || test $REPLACE_BTOWC = 1; then
+  AC_LIBOBJ([btowc])
+  gl_PREREQ_BTOWC
+fi
+gl_WCHAR_MODULE_INDICATOR([btowc])
 gl_BYTESWAP
 gl_CANONICALIZE_LGPL
 if test $HAVE_CANONICALIZE_FILE_NAME = 0 || test 
$REPLACE_CANONICALIZE_FILE_NAME = 1; then
@@ -406,6 +424,7 @@ if test $HAVE_ISNANL = 0 || test $REPLACE_ISNAN = 1; then
   gl_PREREQ_ISNANL
 fi
 gl_MATH_MODULE_INDICATOR([isnanl])
+gl_LANGINFO_H
 gl_FUNC_LDEXP
 gl_LD_VERSION_SCRIPT
 gl_VISIBILITY
@@ -440,6 +459,24 @@ fi
 gl_STDLIB_MODULE_INDICATOR([malloc-posix])
 gl_MALLOCA
 gl_MATH_H
+gl_FUNC_MBRTOWC
+if test $HAVE_MBRTOWC = 0 || test $REPLACE_MBRTOWC = 1; then
+  AC_LIBOBJ([mbrtowc])
+  gl_PREREQ_MBRTOWC
+fi
+gl_WCHAR_MODULE_INDICATOR([mbrtowc])
+gl_FUNC_MBSINIT
+if test $HAVE_MBSINIT = 0 || test $REPLACE_MBSINIT = 1; then
+  AC_LIBOBJ([mbsinit])
+  gl_PREREQ_MBSINIT
+fi
+gl_WCHAR_MODULE_INDICATOR([mbsinit])
+gl_FUNC_MBTOWC
+if test $REPLACE_MBTOWC = 1; then
+  AC_LIBOBJ([mbtowc])
+  gl_PREREQ_MBTOWC
+fi
+gl_STDLIB_MODULE_INDICATOR([mbtowc])
 gl_FUNC_MEMCHR
 if test $HAVE_MEMCHR = 0 || test $REPLACE_MEMCHR = 1; then
   AC_LIBOBJ([memchr])
@@ -458,6 +495,11 @@ gl_MULTIARCH
 gl_HEADER_NETDB
 gl_HEADER_NETINET_IN
 AC_PROG_MKDIR_P
+gl_FUNC_NL_LANGINFO
+if test $HAVE_NL_LANGINFO = 0 || test $REPLACE_NL_LANGINFO = 1; then
+  AC_LIBOBJ([nl_langinfo])
+fi
+gl_LANGINFO_MODULE_INDICATOR([nl_langinfo])
 gl_NPROC
 gl_FUNC_OPEN
 if test $REPLACE_OPEN = 1; then
@@ -501,6 +543,11 @@ if test "$ac_cv_header_winsock2_h" = yes; then
   AC_LIBOBJ([recvfrom])
 fi
 gl_SYS_SOCKET_MODULE_INDICATOR([recvfrom])
+gl_REGEX
+if test $ac_use_included_regex = yes; then
+  AC_LIBOBJ([regex])
+  gl_PREREQ_REGEX
+fi
 gl_FUNC_RENAME
 if test $REPLACE_RENAME = 1; then
   AC_LIBOBJ([rename])
@@ -576,12 +623,22 @@ gl_STDDEF_H
 gl_STDINT_H
 gl_STDIO_H
 gl_STDLIB_H
+gl_STRCASE
+if test $HAVE_STRCASECMP = 0; then
+  AC_LIBOBJ([strcasecmp])
+  gl_PREREQ_STRCASECMP
+fi
+if test $HAVE_STRNCASECMP = 0; then
+  AC_LIBOBJ([strncasecmp])
+  gl_PREREQ_STRNCASECMP
+fi
 gl_FUNC_GNU_STRFTIME
 if test $gl_cond_libtool = false; then
   gl_ltlibdeps="$gl_ltlibdeps $LTLIBICONV"
   gl_libdeps="$gl_libdeps $LIBICONV"
 fi
 gl_HEADER_STRING_H
+gl_HEADER_STRINGS_H
 gl_HEADER_SYS_FILE_H
 AC_PROG_MKDIR_P
 gl_HEADER_SYS_SOCKET
@@ -623,6 +680,13 @@ gl_FUNC_VSNPRINTF
 gl_STDIO_MODULE_INDICATOR([vsnprintf])
 AC_SUBST([WARN_CFLAGS])
 gl_WCHAR_H
+gl_FUNC_WCRTOMB
+if test $HAVE_WCRTOMB = 0 || test $REPLACE_WCRTOMB = 1; then
+  AC_LIBOBJ([wcrtomb])
+  gl_PREREQ_WCRTOMB
+fi
+gl_WCHAR_MODULE_INDICATOR([wcrtomb])
+gl_WCTYPE_H
 gl_FUNC_WRITE
 if test $REPLACE_WRITE = 1; then
   AC_LIBOBJ([write])
@@ -789,6 +853,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/basename-lgpl.c
   lib/binary-io.h
   lib/bind.c
+  lib/btowc.c
   lib/byteswap.in.h
   lib/c-ctype.c
   lib/c-ctype.h
@@ -847,6 +912,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/isnanf.c
   lib/isnanl.c
   lib/itold.c
+  lib/langinfo.in.h
   lib/libunistring.valgrind
   lib/listen.c
   lib/localcharset.c
@@ -858,6 +924,10 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/malloca.h
   lib/malloca.valgrind
   lib/math.in.h
+  lib/mbrtowc.c
+  lib/mbsinit.c
+  lib/mbtowc-impl.h
+  lib/mbtowc.c
   lib/memchr.c
   lib/memchr.valgrind
   lib/msvc-inval.c
@@ -866,6 +936,7 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/msvc-nothrow.h
   lib/netdb.in.h
   lib/netinet_in.in.h
+  lib/nl_langinfo.c
   lib/nproc.c
   lib/nproc.h
   lib/open.c
@@ -883,6 +954,12 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/recvfrom.c
   lib/ref-add.sin
   lib/ref-del.sin
+  lib/regcomp.c
+  lib/regex.c
+  lib/regex.h
+  lib/regex_internal.c
+  lib/regex_internal.h
+  lib/regexec.c
   lib/rename.c
   lib/rmdir.c
   lib/safe-read.c
@@ -909,12 +986,16 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/stdint.in.h
   lib/stdio.in.h
   lib/stdlib.in.h
+  lib/strcasecmp.c
+  lib/streq.h
   lib/strftime.c
   lib/strftime.h
   lib/striconveh.c
   lib/striconveh.h
   lib/string.in.h
+  lib/strings.in.h
   lib/stripslash.c
+  lib/strncasecmp.c
   lib/sys_file.in.h
   lib/sys_socket.in.h
   lib/sys_stat.in.h
@@ -941,6 +1022,8 @@ AC_DEFUN([gl_FILE_LIST], [
   lib/vsnprintf.c
   lib/w32sock.h
   lib/wchar.in.h
+  lib/wcrtomb.c
+  lib/wctype.in.h
   lib/write.c
   lib/xsize.h
   m4/00gnulib.m4
@@ -948,6 +1031,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/alloca.m4
   m4/arpa_inet_h.m4
   m4/autobuild.m4
+  m4/btowc.m4
   m4/byteswap.m4
   m4/canonicalize.m4
   m4/ceil.m4
@@ -995,6 +1079,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/isnand.m4
   m4/isnanf.m4
   m4/isnanl.m4
+  m4/langinfo_h.m4
   m4/largefile.m4
   m4/ld-version-script.m4
   m4/ldexp.m4
@@ -1004,6 +1089,9 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/libunistring-base.m4
   m4/libunistring.m4
   m4/localcharset.m4
+  m4/locale-fr.m4
+  m4/locale-ja.m4
+  m4/locale-zh.m4
   m4/locale_h.m4
   m4/longlong.m4
   m4/lstat.m4
@@ -1011,6 +1099,10 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/malloca.m4
   m4/math_h.m4
   m4/mathfunc.m4
+  m4/mbrtowc.m4
+  m4/mbsinit.m4
+  m4/mbstate_t.m4
+  m4/mbtowc.m4
   m4/memchr.m4
   m4/mmap-anon.m4
   m4/mode_t.m4
@@ -1019,6 +1111,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/multiarch.m4
   m4/netdb_h.m4
   m4/netinet_in_h.m4
+  m4/nl_langinfo.m4
   m4/nocrash.m4
   m4/nproc.m4
   m4/open.m4
@@ -1029,6 +1122,7 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/raise.m4
   m4/read.m4
   m4/readlink.m4
+  m4/regex.m4
   m4/rename.m4
   m4/rmdir.m4
   m4/safe-read.m4
@@ -1052,8 +1146,10 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/stdint_h.m4
   m4/stdio_h.m4
   m4/stdlib_h.m4
+  m4/strcase.m4
   m4/strftime.m4
   m4/string_h.m4
+  m4/strings_h.m4
   m4/sys_file_h.m4
   m4/sys_socket_h.m4
   m4/sys_stat_h.m4
@@ -1072,6 +1168,8 @@ AC_DEFUN([gl_FILE_LIST], [
   m4/warnings.m4
   m4/wchar_h.m4
   m4/wchar_t.m4
+  m4/wcrtomb.m4
+  m4/wctype_h.m4
   m4/wint_t.m4
   m4/write.m4
   m4/xsize.m4
diff --git a/m4/langinfo_h.m4 b/m4/langinfo_h.m4
new file mode 100644
index 0000000..b93fe70
--- /dev/null
+++ b/m4/langinfo_h.m4
@@ -0,0 +1,105 @@
+# langinfo_h.m4 serial 7
+dnl Copyright (C) 2009-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_LANGINFO_H],
+[
+  AC_REQUIRE([gl_LANGINFO_H_DEFAULTS])
+
+  dnl Persuade glibc-2.0.6 <langinfo.h> to define CODESET.
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+  dnl <langinfo.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([langinfo.h])
+
+  dnl Determine whether <langinfo.h> exists. It is missing on mingw and BeOS.
+  HAVE_LANGINFO_CODESET=0
+  HAVE_LANGINFO_T_FMT_AMPM=0
+  HAVE_LANGINFO_ERA=0
+  HAVE_LANGINFO_YESEXPR=0
+  AC_CHECK_HEADERS_ONCE([langinfo.h])
+  if test $ac_cv_header_langinfo_h = yes; then
+    HAVE_LANGINFO_H=1
+    dnl Determine what <langinfo.h> defines. CODESET and ERA etc. are missing
+    dnl on OpenBSD 3.8. T_FMT_AMPM and YESEXPR, NOEXPR are missing on IRIX 5.3.
+    AC_CACHE_CHECK([whether langinfo.h defines CODESET],
+      [gl_cv_header_langinfo_codeset],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[#include <langinfo.h>
+int a = CODESET;
+]])],
+         [gl_cv_header_langinfo_codeset=yes],
+         [gl_cv_header_langinfo_codeset=no])
+      ])
+    if test $gl_cv_header_langinfo_codeset = yes; then
+      HAVE_LANGINFO_CODESET=1
+    fi
+    AC_CACHE_CHECK([whether langinfo.h defines T_FMT_AMPM],
+      [gl_cv_header_langinfo_t_fmt_ampm],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[#include <langinfo.h>
+int a = T_FMT_AMPM;
+]])],
+         [gl_cv_header_langinfo_t_fmt_ampm=yes],
+         [gl_cv_header_langinfo_t_fmt_ampm=no])
+      ])
+    if test $gl_cv_header_langinfo_t_fmt_ampm = yes; then
+      HAVE_LANGINFO_T_FMT_AMPM=1
+    fi
+    AC_CACHE_CHECK([whether langinfo.h defines ERA],
+      [gl_cv_header_langinfo_era],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[#include <langinfo.h>
+int a = ERA;
+]])],
+         [gl_cv_header_langinfo_era=yes],
+         [gl_cv_header_langinfo_era=no])
+      ])
+    if test $gl_cv_header_langinfo_era = yes; then
+      HAVE_LANGINFO_ERA=1
+    fi
+    AC_CACHE_CHECK([whether langinfo.h defines YESEXPR],
+      [gl_cv_header_langinfo_yesexpr],
+      [AC_COMPILE_IFELSE(
+         [AC_LANG_PROGRAM([[#include <langinfo.h>
+int a = YESEXPR;
+]])],
+         [gl_cv_header_langinfo_yesexpr=yes],
+         [gl_cv_header_langinfo_yesexpr=no])
+      ])
+    if test $gl_cv_header_langinfo_yesexpr = yes; then
+      HAVE_LANGINFO_YESEXPR=1
+    fi
+  else
+    HAVE_LANGINFO_H=0
+  fi
+  AC_SUBST([HAVE_LANGINFO_H])
+  AC_SUBST([HAVE_LANGINFO_CODESET])
+  AC_SUBST([HAVE_LANGINFO_T_FMT_AMPM])
+  AC_SUBST([HAVE_LANGINFO_ERA])
+  AC_SUBST([HAVE_LANGINFO_YESEXPR])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[#include <langinfo.h>
+    ]], [nl_langinfo])
+])
+
+AC_DEFUN([gl_LANGINFO_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_LANGINFO_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_LANGINFO_H_DEFAULTS],
+[
+  GNULIB_NL_LANGINFO=0;  AC_SUBST([GNULIB_NL_LANGINFO])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_NL_LANGINFO=1;    AC_SUBST([HAVE_NL_LANGINFO])
+  REPLACE_NL_LANGINFO=0; AC_SUBST([REPLACE_NL_LANGINFO])
+])
diff --git a/m4/locale-fr.m4 b/m4/locale-fr.m4
new file mode 100644
index 0000000..4cb14b5
--- /dev/null
+++ b/m4/locale-fr.m4
@@ -0,0 +1,246 @@
+# locale-fr.m4 serial 14
+dnl Copyright (C) 2003, 2005-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Determine the name of a french locale with traditional encoding.
+AC_DEFUN([gt_LOCALE_FR],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a traditional french locale], [gt_cv_locale_fr], [
+    AC_LANG_CONFTEST([AC_LANG_SOURCE([
+changequote(,)dnl
+#include <locale.h>
+#include <time.h>
+#if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+struct tm t;
+char buf[16];
+int main () {
+  /* Check whether the given locale name is recognized by the system.  */
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+  /* On native Windows, setlocale(category, "") looks at the system settings,
+     not at the environment variables.  Also, when an encoding suffix such
+     as ".65001" or ".54936" is speficied, it succeeds but sets the LC_CTYPE
+     category of the locale to "C".  */
+  if (setlocale (LC_ALL, getenv ("LC_ALL")) == NULL
+      || strcmp (setlocale (LC_CTYPE, NULL), "C") == 0)
+    return 1;
+#else
+  if (setlocale (LC_ALL, "") == NULL) return 1;
+#endif
+  /* Check whether nl_langinfo(CODESET) is nonempty and not "ASCII" or "646".
+     On MacOS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.
+     On MirBSD 10, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "UTF-8".  */
+#if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 0
+        || strcmp (cs, "UTF-8") == 0)
+      return 1;
+  }
+#endif
+#ifdef __CYGWIN__
+  /* On Cygwin, avoid locale names without encoding suffix, because the
+     locale_charset() function relies on the encoding suffix.  Note that
+     LC_ALL is set on the command line.  */
+  if (strchr (getenv ("LC_ALL"), '.') == NULL) return 1;
+#endif
+  /* Check whether in the abbreviation of the second month, the second
+     character (should be U+00E9: LATIN SMALL LETTER E WITH ACUTE) is only
+     one byte long. This excludes the UTF-8 encoding.  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%b", &t) < 3 || buf[2] != 'v') return 1;
+  /* Check whether the decimal separator is a comma.
+     On NetBSD 3.0 in the fr_FR.ISO8859-1 locale, localeconv()->decimal_point
+     are nl_langinfo(RADIXCHAR) are both ".".  */
+  if (localeconv () ->decimal_point[0] != ',') return 1;
+  return 0;
+}
+changequote([,])dnl
+      ])])
+    if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+      case "$host_os" in
+        # Handle native Windows specially, because there setlocale() interprets
+        # "ar" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Test for the native Windows locale name.
+          if (LC_ALL=French_France.1252 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+            gt_cv_locale_fr=French_France.1252
+          else
+            # None found.
+            gt_cv_locale_fr=none
+          fi
+          ;;
+        *)
+          # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+          # otherwise on MacOS X 10.3.5 the LC_TIME=C from the beginning of the
+          # configure script would override the LC_ALL setting. Likewise for
+          # LC_CTYPE, which is also set at the beginning of the configure 
script.
+          # Test for the usual locale name.
+          if (LC_ALL=fr_FR LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; 
then
+            gt_cv_locale_fr=fr_FR
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=fr_FR.ISO-8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+              gt_cv_locale_fr=fr_FR.ISO-8859-1
+            else
+              # Test for the AIX, OSF/1, FreeBSD, NetBSD, OpenBSD locale name.
+              if (LC_ALL=fr_FR.ISO8859-1 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                gt_cv_locale_fr=fr_FR.ISO8859-1
+              else
+                # Test for the HP-UX locale name.
+                if (LC_ALL=fr_FR.iso88591 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                  gt_cv_locale_fr=fr_FR.iso88591
+                else
+                  # Test for the Solaris 7 locale name.
+                  if (LC_ALL=fr LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                    gt_cv_locale_fr=fr
+                  else
+                    # None found.
+                    gt_cv_locale_fr=none
+                  fi
+                fi
+              fi
+            fi
+          fi
+          ;;
+      esac
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_FR=$gt_cv_locale_fr
+  AC_SUBST([LOCALE_FR])
+])
+
+dnl Determine the name of a french locale with UTF-8 encoding.
+AC_DEFUN([gt_LOCALE_FR_UTF8],
+[
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a french Unicode locale], [gt_cv_locale_fr_utf8], [
+    AC_LANG_CONFTEST([AC_LANG_SOURCE([
+changequote(,)dnl
+#include <locale.h>
+#include <time.h>
+#if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+struct tm t;
+char buf[16];
+int main () {
+  /* On BeOS and Haiku, locales are not implemented in libc.  Rather, libintl
+     imitates locale dependent behaviour by looking at the environment
+     variables, and all locales use the UTF-8 encoding.  */
+#if !(defined __BEOS__ || defined __HAIKU__)
+  /* Check whether the given locale name is recognized by the system.  */
+# if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+  /* On native Windows, setlocale(category, "") looks at the system settings,
+     not at the environment variables.  Also, when an encoding suffix such
+     as ".65001" or ".54936" is speficied, it succeeds but sets the LC_CTYPE
+     category of the locale to "C".  */
+  if (setlocale (LC_ALL, getenv ("LC_ALL")) == NULL
+      || strcmp (setlocale (LC_CTYPE, NULL), "C") == 0)
+    return 1;
+# else
+  if (setlocale (LC_ALL, "") == NULL) return 1;
+# endif
+  /* Check whether nl_langinfo(CODESET) is nonempty and not "ASCII" or "646".
+     On MacOS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.  */
+# if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 0)
+      return 1;
+  }
+# endif
+# ifdef __CYGWIN__
+  /* On Cygwin, avoid locale names without encoding suffix, because the
+     locale_charset() function relies on the encoding suffix.  Note that
+     LC_ALL is set on the command line.  */
+  if (strchr (getenv ("LC_ALL"), '.') == NULL) return 1;
+# endif
+  /* Check whether in the abbreviation of the second month, the second
+     character (should be U+00E9: LATIN SMALL LETTER E WITH ACUTE) is
+     two bytes long, with UTF-8 encoding.  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%b", &t) < 4
+      || buf[1] != (char) 0xc3 || buf[2] != (char) 0xa9 || buf[3] != 'v')
+    return 1;
+#endif
+  /* Check whether the decimal separator is a comma.
+     On NetBSD 3.0 in the fr_FR.ISO8859-1 locale, localeconv()->decimal_point
+     are nl_langinfo(RADIXCHAR) are both ".".  */
+  if (localeconv () ->decimal_point[0] != ',') return 1;
+  return 0;
+}
+changequote([,])dnl
+      ])])
+    if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+      case "$host_os" in
+        # Handle native Windows specially, because there setlocale() interprets
+        # "ar" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Test for the hypothetical native Windows locale name.
+          if (LC_ALL=French_France.65001 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+            gt_cv_locale_fr_utf8=French_France.65001
+          else
+            # None found.
+            gt_cv_locale_fr_utf8=none
+          fi
+          ;;
+        *)
+          # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+          # otherwise on MacOS X 10.3.5 the LC_TIME=C from the beginning of the
+          # configure script would override the LC_ALL setting. Likewise for
+          # LC_CTYPE, which is also set at the beginning of the configure 
script.
+          # Test for the usual locale name.
+          if (LC_ALL=fr_FR LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; 
then
+            gt_cv_locale_fr_utf8=fr_FR
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=fr_FR.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+              gt_cv_locale_fr_utf8=fr_FR.UTF-8
+            else
+              # Test for the Solaris 7 locale name.
+              if (LC_ALL=fr.UTF-8 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                gt_cv_locale_fr_utf8=fr.UTF-8
+              else
+                # None found.
+                gt_cv_locale_fr_utf8=none
+              fi
+            fi
+          fi
+          ;;
+      esac
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_FR_UTF8=$gt_cv_locale_fr_utf8
+  AC_SUBST([LOCALE_FR_UTF8])
+])
diff --git a/m4/locale-ja.m4 b/m4/locale-ja.m4
new file mode 100644
index 0000000..b427f09
--- /dev/null
+++ b/m4/locale-ja.m4
@@ -0,0 +1,136 @@
+# locale-ja.m4 serial 10
+dnl Copyright (C) 2003, 2005-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Determine the name of a japanese locale with EUC-JP encoding.
+AC_DEFUN([gt_LOCALE_JA],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a traditional japanese locale], [gt_cv_locale_ja], [
+    AC_LANG_CONFTEST([AC_LANG_SOURCE([
+changequote(,)dnl
+#include <locale.h>
+#include <time.h>
+#if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+struct tm t;
+char buf[16];
+int main ()
+{
+  const char *p;
+  /* Check whether the given locale name is recognized by the system.  */
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+  /* On native Windows, setlocale(category, "") looks at the system settings,
+     not at the environment variables.  Also, when an encoding suffix such
+     as ".65001" or ".54936" is speficied, it succeeds but sets the LC_CTYPE
+     category of the locale to "C".  */
+  if (setlocale (LC_ALL, getenv ("LC_ALL")) == NULL
+      || strcmp (setlocale (LC_CTYPE, NULL), "C") == 0)
+    return 1;
+#else
+  if (setlocale (LC_ALL, "") == NULL) return 1;
+#endif
+  /* Check whether nl_langinfo(CODESET) is nonempty and not "ASCII" or "646".
+     On MacOS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.
+     On MirBSD 10, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "UTF-8".  */
+#if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 0
+        || strcmp (cs, "UTF-8") == 0)
+      return 1;
+  }
+#endif
+#ifdef __CYGWIN__
+  /* On Cygwin, avoid locale names without encoding suffix, because the
+     locale_charset() function relies on the encoding suffix.  Note that
+     LC_ALL is set on the command line.  */
+  if (strchr (getenv ("LC_ALL"), '.') == NULL) return 1;
+#endif
+  /* Check whether MB_CUR_MAX is > 1.  This excludes the dysfunctional locales
+     on Cygwin 1.5.x.  */
+  if (MB_CUR_MAX == 1)
+    return 1;
+  /* Check whether in a month name, no byte in the range 0x80..0x9F occurs.
+     This excludes the UTF-8 encoding (except on MirBSD).  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%B", &t) < 2) return 1;
+  for (p = buf; *p != '\0'; p++)
+    if ((unsigned char) *p >= 0x80 && (unsigned char) *p < 0xa0)
+      return 1;
+  return 0;
+}
+changequote([,])dnl
+      ])])
+    if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+      case "$host_os" in
+        # Handle native Windows specially, because there setlocale() interprets
+        # "ar" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Note that on native Windows, the Japanese locale is
+          # Japanese_Japan.932, and CP932 is very different from EUC-JP, so we
+          # cannot use it here.
+          gt_cv_locale_ja=none
+          ;;
+        *)
+          # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+          # otherwise on MacOS X 10.3.5 the LC_TIME=C from the beginning of the
+          # configure script would override the LC_ALL setting. Likewise for
+          # LC_CTYPE, which is also set at the beginning of the configure 
script.
+          # Test for the AIX locale name.
+          if (LC_ALL=ja_JP LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; 
then
+            gt_cv_locale_ja=ja_JP
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=ja_JP.EUC-JP LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+              gt_cv_locale_ja=ja_JP.EUC-JP
+            else
+              # Test for the HP-UX, OSF/1, NetBSD locale name.
+              if (LC_ALL=ja_JP.eucJP LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                gt_cv_locale_ja=ja_JP.eucJP
+              else
+                # Test for the IRIX, FreeBSD locale name.
+                if (LC_ALL=ja_JP.EUC LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                  gt_cv_locale_ja=ja_JP.EUC
+                else
+                  # Test for the Solaris 7 locale name.
+                  if (LC_ALL=ja LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+                    gt_cv_locale_ja=ja
+                  else
+                    # Special test for NetBSD 1.6.
+                    if test -f /usr/share/locale/ja_JP.eucJP/LC_CTYPE; then
+                      gt_cv_locale_ja=ja_JP.eucJP
+                    else
+                      # None found.
+                      gt_cv_locale_ja=none
+                    fi
+                  fi
+                fi
+              fi
+            fi
+          fi
+          ;;
+      esac
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_JA=$gt_cv_locale_ja
+  AC_SUBST([LOCALE_JA])
+])
diff --git a/m4/locale-zh.m4 b/m4/locale-zh.m4
new file mode 100644
index 0000000..de1a43b
--- /dev/null
+++ b/m4/locale-zh.m4
@@ -0,0 +1,130 @@
+# locale-zh.m4 serial 10
+dnl Copyright (C) 2003, 2005-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Determine the name of a chinese locale with GB18030 encoding.
+AC_DEFUN([gt_LOCALE_ZH_CN],
+[
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_REQUIRE([AM_LANGINFO_CODESET])
+  AC_CACHE_CHECK([for a transitional chinese locale], [gt_cv_locale_zh_CN], [
+    AC_LANG_CONFTEST([AC_LANG_SOURCE([
+changequote(,)dnl
+#include <locale.h>
+#include <stdlib.h>
+#include <time.h>
+#if HAVE_LANGINFO_CODESET
+# include <langinfo.h>
+#endif
+#include <stdlib.h>
+#include <string.h>
+struct tm t;
+char buf[16];
+int main ()
+{
+  const char *p;
+  /* Check whether the given locale name is recognized by the system.  */
+#if (defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__
+  /* On native Windows, setlocale(category, "") looks at the system settings,
+     not at the environment variables.  Also, when an encoding suffix such
+     as ".65001" or ".54936" is speficied, it succeeds but sets the LC_CTYPE
+     category of the locale to "C".  */
+  if (setlocale (LC_ALL, getenv ("LC_ALL")) == NULL
+      || strcmp (setlocale (LC_CTYPE, NULL), "C") == 0)
+    return 1;
+#else
+  if (setlocale (LC_ALL, "") == NULL) return 1;
+#endif
+  /* Check whether nl_langinfo(CODESET) is nonempty and not "ASCII" or "646".
+     On MacOS X 10.3.5 (Darwin 7.5) in the fr_FR locale, nl_langinfo(CODESET)
+     is empty, and the behaviour of Tcl 8.4 in this locale is not useful.
+     On OpenBSD 4.0, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "646". In this situation,
+     some unit tests fail.
+     On MirBSD 10, when an unsupported locale is specified, setlocale()
+     succeeds but then nl_langinfo(CODESET) is "UTF-8".  */
+#if HAVE_LANGINFO_CODESET
+  {
+    const char *cs = nl_langinfo (CODESET);
+    if (cs[0] == '\0' || strcmp (cs, "ASCII") == 0 || strcmp (cs, "646") == 0
+        || strcmp (cs, "UTF-8") == 0)
+      return 1;
+  }
+#endif
+#ifdef __CYGWIN__
+  /* On Cygwin, avoid locale names without encoding suffix, because the
+     locale_charset() function relies on the encoding suffix.  Note that
+     LC_ALL is set on the command line.  */
+  if (strchr (getenv ("LC_ALL"), '.') == NULL) return 1;
+#endif
+  /* Check whether in a month name, no byte in the range 0x80..0x9F occurs.
+     This excludes the UTF-8 encoding (except on MirBSD).  */
+  t.tm_year = 1975 - 1900; t.tm_mon = 2 - 1; t.tm_mday = 4;
+  if (strftime (buf, sizeof (buf), "%B", &t) < 2) return 1;
+  for (p = buf; *p != '\0'; p++)
+    if ((unsigned char) *p >= 0x80 && (unsigned char) *p < 0xa0)
+      return 1;
+  /* Check whether a typical GB18030 multibyte sequence is recognized as a
+     single wide character.  This excludes the GB2312 and GBK encodings.  */
+  if (mblen ("\203\062\332\066", 5) != 4)
+    return 1;
+  return 0;
+}
+changequote([,])dnl
+      ])])
+    if AC_TRY_EVAL([ac_link]) && test -s conftest$ac_exeext; then
+      case "$host_os" in
+        # Handle native Windows specially, because there setlocale() interprets
+        # "ar" as "Arabic" or "Arabic_Saudi Arabia.1256",
+        # "fr" or "fra" as "French" or "French_France.1252",
+        # "ge"(!) or "deu"(!) as "German" or "German_Germany.1252",
+        # "ja" as "Japanese" or "Japanese_Japan.932",
+        # and similar.
+        mingw*)
+          # Test for the hypothetical native Windows locale name.
+          if (LC_ALL=Chinese_China.54936 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+            gt_cv_locale_zh_CN=Chinese_China.54936
+          else
+            # None found.
+            gt_cv_locale_zh_CN=none
+          fi
+          ;;
+        solaris2.8)
+          # On Solaris 8, the locales zh_CN.GB18030, zh_CN.GBK, zh.GBK are
+          # broken. One witness is the test case in gl_MBRTOWC_SANITYCHECK.
+          # Another witness is that "LC_ALL=zh_CN.GB18030 bash -c true" dumps 
core.
+          gt_cv_locale_zh_CN=none
+          ;;
+        *)
+          # Setting LC_ALL is not enough. Need to set LC_TIME to empty, because
+          # otherwise on MacOS X 10.3.5 the LC_TIME=C from the beginning of the
+          # configure script would override the LC_ALL setting. Likewise for
+          # LC_CTYPE, which is also set at the beginning of the configure 
script.
+          # Test for the locale name without encoding suffix.
+          if (LC_ALL=zh_CN LC_TIME= LC_CTYPE= ./conftest; exit) 2>/dev/null; 
then
+            gt_cv_locale_zh_CN=zh_CN
+          else
+            # Test for the locale name with explicit encoding suffix.
+            if (LC_ALL=zh_CN.GB18030 LC_TIME= LC_CTYPE= ./conftest; exit) 
2>/dev/null; then
+              gt_cv_locale_zh_CN=zh_CN.GB18030
+            else
+              # None found.
+              gt_cv_locale_zh_CN=none
+            fi
+          fi
+          ;;
+      esac
+    else
+      # If there was a link error, due to mblen(), the system is so old that
+      # it certainly doesn't have a chinese locale.
+      gt_cv_locale_zh_CN=none
+    fi
+    rm -fr conftest*
+  ])
+  LOCALE_ZH_CN=$gt_cv_locale_zh_CN
+  AC_SUBST([LOCALE_ZH_CN])
+])
diff --git a/m4/mbrtowc.m4 b/m4/mbrtowc.m4
new file mode 100644
index 0000000..8f829c8
--- /dev/null
+++ b/m4/mbrtowc.m4
@@ -0,0 +1,572 @@
+# mbrtowc.m4 serial 25
+dnl Copyright (C) 2001-2002, 2004-2005, 2008-2012 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_MBRTOWC],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  gl_MBSTATE_T_BROKEN
+
+  AC_CHECK_FUNCS_ONCE([mbrtowc])
+  if test $ac_cv_func_mbrtowc = no; then
+    HAVE_MBRTOWC=0
+    AC_CHECK_DECLS([mbrtowc],,, [[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+]])
+    if test $ac_cv_have_decl_mbrtowc = yes; then
+      dnl On Minix 3.1.8, the system's <wchar.h> declares mbrtowc() although
+      dnl it does not have the function. Avoid a collision with gnulib's
+      dnl replacement.
+      REPLACE_MBRTOWC=1
+    fi
+  else
+    if test $REPLACE_MBSTATE_T = 1; then
+      REPLACE_MBRTOWC=1
+    else
+      gl_MBRTOWC_NULL_ARG1
+      gl_MBRTOWC_NULL_ARG2
+      gl_MBRTOWC_RETVAL
+      gl_MBRTOWC_NUL_RETVAL
+      case "$gl_cv_func_mbrtowc_null_arg1" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_NULL_ARG1_BUG], [1],
+             [Define if the mbrtowc function has the NULL pwc argument bug.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+      case "$gl_cv_func_mbrtowc_null_arg2" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_NULL_ARG2_BUG], [1],
+             [Define if the mbrtowc function has the NULL string argument 
bug.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+      case "$gl_cv_func_mbrtowc_retval" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_RETVAL_BUG], [1],
+             [Define if the mbrtowc function returns a wrong return value.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+      case "$gl_cv_func_mbrtowc_nul_retval" in
+        *yes) ;;
+        *) AC_DEFINE([MBRTOWC_NUL_RETVAL_BUG], [1],
+             [Define if the mbrtowc function does not return 0 for a NUL 
character.])
+           REPLACE_MBRTOWC=1
+           ;;
+      esac
+    fi
+  fi
+])
+
+dnl Test whether mbsinit() and mbrtowc() need to be overridden in a way that
+dnl redefines the semantics of the given mbstate_t type.
+dnl Result is REPLACE_MBSTATE_T.
+dnl When this is set to 1, we replace both mbsinit() and mbrtowc(), in order to
+dnl avoid inconsistencies.
+
+AC_DEFUN([gl_MBSTATE_T_BROKEN],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  AC_CHECK_FUNCS_ONCE([mbsinit])
+  AC_CHECK_FUNCS_ONCE([mbrtowc])
+  if test $ac_cv_func_mbsinit = yes && test $ac_cv_func_mbrtowc = yes; then
+    gl_MBRTOWC_INCOMPLETE_STATE
+    gl_MBRTOWC_SANITYCHECK
+    REPLACE_MBSTATE_T=0
+    case "$gl_cv_func_mbrtowc_incomplete_state" in
+      *yes) ;;
+      *) REPLACE_MBSTATE_T=1 ;;
+    esac
+    case "$gl_cv_func_mbrtowc_sanitycheck" in
+      *yes) ;;
+      *) REPLACE_MBSTATE_T=1 ;;
+    esac
+  else
+    REPLACE_MBSTATE_T=1
+  fi
+])
+
+dnl Test whether mbrtowc puts the state into non-initial state when parsing an
+dnl incomplete multibyte character.
+dnl Result is gl_cv_func_mbrtowc_incomplete_state.
+
+AC_DEFUN([gl_MBRTOWC_INCOMPLETE_STATE],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_JA])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc handles incomplete characters],
+    [gl_cv_func_mbrtowc_incomplete_state],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                     # Guess no on AIX and OSF/1.
+        aix* | osf*) gl_cv_func_mbrtowc_incomplete_state="guessing no" ;;
+                     # Guess yes otherwise.
+        *)           gl_cv_func_mbrtowc_incomplete_state="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_JA != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_JA") != NULL)
+    {
+      const char input[] = "B\217\253\344\217\251\316er"; /* "Büßer" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 1, 1, &state) == (size_t)(-2))
+        if (mbsinit (&state))
+          return 1;
+    }
+  return 0;
+}]])],
+          [gl_cv_func_mbrtowc_incomplete_state=yes],
+          [gl_cv_func_mbrtowc_incomplete_state=no],
+          [:])
+      fi
+    ])
+])
+
+dnl Test whether mbrtowc works not worse than mbtowc.
+dnl Result is gl_cv_func_mbrtowc_sanitycheck.
+
+AC_DEFUN([gl_MBRTOWC_SANITYCHECK],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_ZH_CN])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc works as well as mbtowc],
+    [gl_cv_func_mbrtowc_sanitycheck],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                    # Guess no on Solaris 8.
+        solaris2.8) gl_cv_func_mbrtowc_sanitycheck="guessing no" ;;
+                    # Guess yes otherwise.
+        *)          gl_cv_func_mbrtowc_sanitycheck="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_ZH_CN != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  /* This fails on Solaris 8:
+     mbrtowc returns 2, and sets wc to 0x00F0.
+     mbtowc returns 4 (correct) and sets wc to 0x5EDC.  */
+  if (setlocale (LC_ALL, "$LOCALE_ZH_CN") != NULL)
+    {
+      char input[] = "B\250\271\201\060\211\070er"; /* "Büßer" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 3, 6, &state) != 4
+          && mbtowc (&wc, input + 3, 6) == 4)
+        return 1;
+    }
+  return 0;
+}]])],
+          [gl_cv_func_mbrtowc_sanitycheck=yes],
+          [gl_cv_func_mbrtowc_sanitycheck=no],
+          [:])
+      fi
+    ])
+])
+
+dnl Test whether mbrtowc supports a NULL pwc argument correctly.
+dnl Result is gl_cv_func_mbrtowc_null_arg1.
+
+AC_DEFUN([gl_MBRTOWC_NULL_ARG1],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_FR_UTF8])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc handles a NULL pwc argument],
+    [gl_cv_func_mbrtowc_null_arg1],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                  # Guess no on Solaris.
+        solaris*) gl_cv_func_mbrtowc_null_arg1="guessing no" ;;
+                  # Guess yes otherwise.
+        *)        gl_cv_func_mbrtowc_null_arg1="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_FR_UTF8 != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  int result = 0;
+
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      char input[] = "\303\237er";
+      mbstate_t state;
+      wchar_t wc;
+      size_t ret;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      wc = (wchar_t) 0xBADFACE;
+      ret = mbrtowc (&wc, input, 5, &state);
+      if (ret != 2)
+        result |= 1;
+      if (!mbsinit (&state))
+        result |= 2;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      ret = mbrtowc (NULL, input, 5, &state);
+      if (ret != 2) /* Solaris 7 fails here: ret is -1.  */
+        result |= 4;
+      if (!mbsinit (&state))
+        result |= 8;
+    }
+  return result;
+}]])],
+          [gl_cv_func_mbrtowc_null_arg1=yes],
+          [gl_cv_func_mbrtowc_null_arg1=no],
+          [:])
+      fi
+    ])
+])
+
+dnl Test whether mbrtowc supports a NULL string argument correctly.
+dnl Result is gl_cv_func_mbrtowc_null_arg2.
+
+AC_DEFUN([gl_MBRTOWC_NULL_ARG2],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_FR_UTF8])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc handles a NULL string argument],
+    [gl_cv_func_mbrtowc_null_arg2],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+              # Guess no on OSF/1.
+        osf*) gl_cv_func_mbrtowc_null_arg2="guessing no" ;;
+              # Guess yes otherwise.
+        *)    gl_cv_func_mbrtowc_null_arg2="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_FR_UTF8 != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      mbstate_t state;
+      wchar_t wc;
+      int ret;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      wc = (wchar_t) 0xBADFACE;
+      mbrtowc (&wc, NULL, 5, &state);
+      /* Check that wc was not modified.  */
+      if (wc != (wchar_t) 0xBADFACE)
+        return 1;
+    }
+  return 0;
+}]])],
+          [gl_cv_func_mbrtowc_null_arg2=yes],
+          [gl_cv_func_mbrtowc_null_arg2=no],
+          [:])
+      fi
+    ])
+])
+
+dnl Test whether mbrtowc, when parsing the end of a multibyte character,
+dnl correctly returns the number of bytes that were needed to complete the
+dnl character (not the total number of bytes of the multibyte character).
+dnl Result is gl_cv_func_mbrtowc_retval.
+
+AC_DEFUN([gl_MBRTOWC_RETVAL],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_FR_UTF8])
+  AC_REQUIRE([gt_LOCALE_JA])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CACHE_CHECK([whether mbrtowc has a correct return value],
+    [gl_cv_func_mbrtowc_retval],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                                   # Guess no on HP-UX, Solaris, native 
Windows.
+        hpux* | solaris* | mingw*) gl_cv_func_mbrtowc_retval="guessing no" ;;
+                                   # Guess yes otherwise.
+        *)                         gl_cv_func_mbrtowc_retval="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_FR_UTF8 != none || test $LOCALE_JA != none \
+         || { case "$host_os" in mingw*) true;; *) false;; esac; }; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  int result = 0;
+  int found_some_locale = 0;
+  /* This fails on Solaris.  */
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      char input[] = "B\303\274\303\237er"; /* "Büßer" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 1, 1, &state) == (size_t)(-2))
+        {
+          input[1] = '\0';
+          if (mbrtowc (&wc, input + 2, 5, &state) != 1)
+            result |= 1;
+        }
+      found_some_locale = 1;
+    }
+  /* This fails on HP-UX 11.11.  */
+  if (setlocale (LC_ALL, "$LOCALE_JA") != NULL)
+    {
+      char input[] = "B\217\253\344\217\251\316er"; /* "Büßer" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 1, 1, &state) == (size_t)(-2))
+        {
+          input[1] = '\0';
+          if (mbrtowc (&wc, input + 2, 5, &state) != 2)
+            result |= 2;
+        }
+      found_some_locale = 1;
+    }
+  /* This fails on native Windows.  */
+  if (setlocale (LC_ALL, "Japanese_Japan.932") != NULL)
+    {
+      char input[] = "<\223\372\226\173\214\352>"; /* "<日本語>" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 3, 1, &state) == (size_t)(-2))
+        {
+          input[3] = '\0';
+          if (mbrtowc (&wc, input + 4, 4, &state) != 1)
+            result |= 4;
+        }
+      found_some_locale = 1;
+    }
+  if (setlocale (LC_ALL, "Chinese_Taiwan.950") != NULL)
+    {
+      char input[] = "<\244\351\245\273\273\171>"; /* "<日本語>" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 3, 1, &state) == (size_t)(-2))
+        {
+          input[3] = '\0';
+          if (mbrtowc (&wc, input + 4, 4, &state) != 1)
+            result |= 8;
+        }
+      found_some_locale = 1;
+    }
+  if (setlocale (LC_ALL, "Chinese_China.936") != NULL)
+    {
+      char input[] = "<\310\325\261\276\325\132>"; /* "<日本語>" */
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, input + 3, 1, &state) == (size_t)(-2))
+        {
+          input[3] = '\0';
+          if (mbrtowc (&wc, input + 4, 4, &state) != 1)
+            result |= 16;
+        }
+      found_some_locale = 1;
+    }
+  return (found_some_locale ? result : 77);
+}]])],
+          [gl_cv_func_mbrtowc_retval=yes],
+          [if test $? != 77; then
+             gl_cv_func_mbrtowc_retval=no
+           fi
+          ],
+          [:])
+      fi
+    ])
+])
+
+dnl Test whether mbrtowc, when parsing a NUL character, correctly returns 0.
+dnl Result is gl_cv_func_mbrtowc_nul_retval.
+
+AC_DEFUN([gl_MBRTOWC_NUL_RETVAL],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([gt_LOCALE_ZH_CN])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  AC_CACHE_CHECK([whether mbrtowc returns 0 when parsing a NUL character],
+    [gl_cv_func_mbrtowc_nul_retval],
+    [
+      dnl Initial guess, used when cross-compiling or when no suitable locale
+      dnl is present.
+changequote(,)dnl
+      case "$host_os" in
+                       # Guess no on Solaris 8 and 9.
+        solaris2.[89]) gl_cv_func_mbrtowc_nul_retval="guessing no" ;;
+                       # Guess yes otherwise.
+        *)             gl_cv_func_mbrtowc_nul_retval="guessing yes" ;;
+      esac
+changequote([,])dnl
+      if test $LOCALE_ZH_CN != none; then
+        AC_RUN_IFELSE(
+          [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  /* This fails on Solaris 8 and 9.  */
+  if (setlocale (LC_ALL, "$LOCALE_ZH_CN") != NULL)
+    {
+      mbstate_t state;
+      wchar_t wc;
+
+      memset (&state, '\0', sizeof (mbstate_t));
+      if (mbrtowc (&wc, "", 1, &state) != 0)
+        return 1;
+    }
+  return 0;
+}]])],
+          [gl_cv_func_mbrtowc_nul_retval=yes],
+          [gl_cv_func_mbrtowc_nul_retval=no],
+          [:])
+      fi
+    ])
+])
+
+# Prerequisites of lib/mbrtowc.c.
+AC_DEFUN([gl_PREREQ_MBRTOWC], [
+  :
+])
+
+
+dnl From Paul Eggert
+
+dnl This is an override of an autoconf macro.
+
+AC_DEFUN([AC_FUNC_MBRTOWC],
+[
+  dnl Same as AC_FUNC_MBRTOWC in autoconf-2.60.
+  AC_CACHE_CHECK([whether mbrtowc and mbstate_t are properly declared],
+    gl_cv_func_mbrtowc,
+    [AC_LINK_IFELSE(
+       [AC_LANG_PROGRAM(
+            [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
+                 included before <wchar.h>.
+                 BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
+                 must be included before <wchar.h>.  */
+              #include <stddef.h>
+              #include <stdio.h>
+              #include <time.h>
+              #include <wchar.h>]],
+            [[wchar_t wc;
+              char const s[] = "";
+              size_t n = 1;
+              mbstate_t state;
+              return ! (sizeof state && (mbrtowc) (&wc, s, n, &state));]])],
+       gl_cv_func_mbrtowc=yes,
+       gl_cv_func_mbrtowc=no)])
+  if test $gl_cv_func_mbrtowc = yes; then
+    AC_DEFINE([HAVE_MBRTOWC], [1],
+      [Define to 1 if mbrtowc and mbstate_t are properly declared.])
+  fi
+])
diff --git a/m4/mbsinit.m4 b/m4/mbsinit.m4
new file mode 100644
index 0000000..da56c3d
--- /dev/null
+++ b/m4/mbsinit.m4
@@ -0,0 +1,51 @@
+# mbsinit.m4 serial 8
+dnl Copyright (C) 2008, 2010-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_MBSINIT],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  gl_MBSTATE_T_BROKEN
+
+  AC_CHECK_FUNCS_ONCE([mbsinit])
+  if test $ac_cv_func_mbsinit = no; then
+    HAVE_MBSINIT=0
+    AC_CHECK_DECLS([mbsinit],,, [[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+]])
+    if test $ac_cv_have_decl_mbsinit = yes; then
+      dnl On Minix 3.1.8, the system's <wchar.h> declares mbsinit() although
+      dnl it does not have the function. Avoid a collision with gnulib's
+      dnl replacement.
+      REPLACE_MBSINIT=1
+    fi
+  else
+    if test $REPLACE_MBSTATE_T = 1; then
+      REPLACE_MBSINIT=1
+    else
+      dnl On mingw, mbsinit() always returns 1, which is inappropriate for
+      dnl states produced by mbrtowc() for an incomplete multibyte character
+      dnl in multibyte locales.
+      case "$host_os" in
+        mingw*) REPLACE_MBSINIT=1 ;;
+      esac
+    fi
+  fi
+])
+
+# Prerequisites of lib/mbsinit.c.
+AC_DEFUN([gl_PREREQ_MBSINIT], [
+  :
+])
diff --git a/m4/mbstate_t.m4 b/m4/mbstate_t.m4
new file mode 100644
index 0000000..61a8190
--- /dev/null
+++ b/m4/mbstate_t.m4
@@ -0,0 +1,41 @@
+# mbstate_t.m4 serial 13
+dnl Copyright (C) 2000-2002, 2008-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# From Paul Eggert.
+
+# BeOS 5 has <wchar.h> but does not define mbstate_t,
+# so you can't declare an object of that type.
+# Check for this incompatibility with Standard C.
+
+# AC_TYPE_MBSTATE_T
+# -----------------
+AC_DEFUN([AC_TYPE_MBSTATE_T],
+[
+   AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) dnl for HP-UX 11.11
+
+   AC_CACHE_CHECK([for mbstate_t], [ac_cv_type_mbstate_t],
+     [AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM(
+           [AC_INCLUDES_DEFAULT[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>]],
+           [[mbstate_t x; return sizeof x;]])],
+        [ac_cv_type_mbstate_t=yes],
+        [ac_cv_type_mbstate_t=no])])
+   if test $ac_cv_type_mbstate_t = yes; then
+     AC_DEFINE([HAVE_MBSTATE_T], [1],
+               [Define to 1 if <wchar.h> declares mbstate_t.])
+   else
+     AC_DEFINE([mbstate_t], [int],
+               [Define to a type if <wchar.h> does not define.])
+   fi
+])
diff --git a/m4/mbtowc.m4 b/m4/mbtowc.m4
new file mode 100644
index 0000000..fec0d25
--- /dev/null
+++ b/m4/mbtowc.m4
@@ -0,0 +1,19 @@
+# mbtowc.m4 serial 2
+dnl Copyright (C) 2011-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_MBTOWC],
+[
+  AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
+
+  if false; then
+    REPLACE_MBTOWC=1
+  fi
+])
+
+# Prerequisites of lib/mbtowc.c.
+AC_DEFUN([gl_PREREQ_MBTOWC], [
+  :
+])
diff --git a/m4/nl_langinfo.m4 b/m4/nl_langinfo.m4
new file mode 100644
index 0000000..80fe60d
--- /dev/null
+++ b/m4/nl_langinfo.m4
@@ -0,0 +1,50 @@
+# nl_langinfo.m4 serial 5
+dnl Copyright (C) 2009-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_NL_LANGINFO],
+[
+  AC_REQUIRE([gl_LANGINFO_H_DEFAULTS])
+  AC_REQUIRE([gl_LANGINFO_H])
+  AC_CHECK_FUNCS_ONCE([nl_langinfo])
+  AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+  if test $ac_cv_func_nl_langinfo = yes; then
+    # On Irix 6.5, YESEXPR is defined, but nl_langinfo(YESEXPR) is broken.
+    AC_CACHE_CHECK([whether YESEXPR works],
+      [gl_cv_func_nl_langinfo_yesexpr_works],
+      [AC_RUN_IFELSE(
+         [AC_LANG_PROGRAM([[#include <langinfo.h>
+]], [[return !*nl_langinfo(YESEXPR);
+]])],
+         [gl_cv_func_nl_langinfo_yesexpr_works=yes],
+         [gl_cv_func_nl_langinfo_yesexpr_works=no],
+         [
+         case "$host_os" in
+                   # Guess no on irix systems.
+           irix*)  gl_cv_func_nl_langinfo_yesexpr_works="guessing no";;
+                   # Guess yes elsewhere.
+           *)      gl_cv_func_nl_langinfo_yesexpr_works="guessing yes";;
+         esac
+         ])
+      ])
+    case $gl_cv_func_nl_langinfo_yesexpr_works in
+      *yes) FUNC_NL_LANGINFO_YESEXPR_WORKS=1 ;;
+      *)    FUNC_NL_LANGINFO_YESEXPR_WORKS=0 ;;
+    esac
+    AC_DEFINE_UNQUOTED([FUNC_NL_LANGINFO_YESEXPR_WORKS],
+      [$FUNC_NL_LANGINFO_YESEXPR_WORKS],
+      [Define to 1 if nl_langinfo (YESEXPR) returns a non-empty string.])
+    if test $HAVE_LANGINFO_CODESET = 1 && test $HAVE_LANGINFO_ERA = 1 \
+        && test $FUNC_NL_LANGINFO_YESEXPR_WORKS = 1; then
+      :
+    else
+      REPLACE_NL_LANGINFO=1
+      AC_DEFINE([REPLACE_NL_LANGINFO], [1],
+        [Define if nl_langinfo exists but is overridden by gnulib.])
+    fi
+  else
+    HAVE_NL_LANGINFO=0
+  fi
+])
diff --git a/m4/regex.m4 b/m4/regex.m4
new file mode 100644
index 0000000..08f1352
--- /dev/null
+++ b/m4/regex.m4
@@ -0,0 +1,223 @@
+# serial 60
+
+# Copyright (C) 1996-2001, 2003-2012 Free Software Foundation, Inc.
+#
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+dnl Initially derived from code in GNU grep.
+dnl Mostly written by Jim Meyering.
+
+AC_PREREQ([2.50])
+
+AC_DEFUN([gl_REGEX],
+[
+  AC_ARG_WITH([included-regex],
+    [AS_HELP_STRING([--without-included-regex],
+                    [don't compile regex; this is the default on systems
+                     with recent-enough versions of the GNU C Library
+                     (use with caution on other systems).])])
+
+  case $with_included_regex in #(
+  yes|no) ac_use_included_regex=$with_included_regex
+        ;;
+  '')
+    # If the system regex support is good enough that it passes the
+    # following run test, then default to *not* using the included regex.c.
+    # If cross compiling, assume the test would fail and use the included
+    # regex.c.
+    AC_CACHE_CHECK([for working re_compile_pattern],
+                   [gl_cv_func_re_compile_pattern_working],
+      [AC_RUN_IFELSE(
+        [AC_LANG_PROGRAM(
+          [AC_INCLUDES_DEFAULT[
+           #include <locale.h>
+           #include <limits.h>
+           #include <regex.h>
+           ]],
+          [[int result = 0;
+            static struct re_pattern_buffer regex;
+            unsigned char folded_chars[UCHAR_MAX + 1];
+            int i;
+            const char *s;
+            struct re_registers regs;
+
+            /* http://sourceware.org/ml/libc-hacker/2006-09/msg00008.html
+               This test needs valgrind to catch the bug on Debian
+               GNU/Linux 3.1 x86, but it might catch the bug better
+               on other platforms and it shouldn't hurt to try the
+               test here.  */
+            if (setlocale (LC_ALL, "en_US.UTF-8"))
+              {
+                static char const pat[] = "insert into";
+                static char const data[] =
+                  "\xFF\0\x12\xA2\xAA\xC4\xB1,K\x12\xC4\xB1*\xACK";
+                re_set_syntax (RE_SYNTAX_GREP | RE_HAT_LISTS_NOT_NEWLINE
+                               | RE_ICASE);
+                memset (&regex, 0, sizeof regex);
+                s = re_compile_pattern (pat, sizeof pat - 1, &regex);
+                if (s)
+                  result |= 1;
+                else if (re_search (&regex, data, sizeof data - 1,
+                                    0, sizeof data - 1, &regs)
+                         != -1)
+                  result |= 1;
+                if (! setlocale (LC_ALL, "C"))
+                  return 1;
+              }
+
+            /* This test is from glibc bug 3957, reported by Andrew Mackey.  */
+            re_set_syntax (RE_SYNTAX_EGREP | RE_HAT_LISTS_NOT_NEWLINE);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("a[^x]b", 6, &regex);
+            if (s)
+              result |= 2;
+            /* This should fail, but succeeds for glibc-2.5.  */
+            else if (re_search (&regex, "a\nb", 3, 0, 3, &regs) != -1)
+              result |= 2;
+
+            /* This regular expression is from Spencer ere test number 75
+               in grep-2.3.  */
+            re_set_syntax (RE_SYNTAX_POSIX_EGREP);
+            memset (&regex, 0, sizeof regex);
+            for (i = 0; i <= UCHAR_MAX; i++)
+              folded_chars[i] = i;
+            regex.translate = folded_chars;
+            s = re_compile_pattern ("a[[:@:>@:]]b\n", 11, &regex);
+            /* This should fail with _Invalid character class name_ error.  */
+            if (!s)
+              result |= 4;
+
+            /* Ensure that [b-a] is diagnosed as invalid, when
+               using RE_NO_EMPTY_RANGES. */
+            re_set_syntax (RE_SYNTAX_POSIX_EGREP | RE_NO_EMPTY_RANGES);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("a[b-a]", 6, &regex);
+            if (s == 0)
+              result |= 8;
+
+            /* This should succeed, but does not for glibc-2.1.3.  */
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("{1", 2, &regex);
+            if (s)
+              result |= 8;
+
+            /* The following example is derived from a problem report
+               against gawk from Jorge Stolfi <address@hidden>.  */
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("[an\371]*n", 7, &regex);
+            if (s)
+              result |= 8;
+            /* This should match, but does not for glibc-2.2.1.  */
+            else if (re_match (&regex, "an", 2, 0, &regs) != 2)
+              result |= 8;
+
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("x", 1, &regex);
+            if (s)
+              result |= 8;
+            /* glibc-2.2.93 does not work with a negative RANGE argument.  */
+            else if (re_search (&regex, "wxy", 3, 2, -2, &regs) != 1)
+              result |= 8;
+
+            /* The version of regex.c in older versions of gnulib
+               ignored RE_ICASE.  Detect that problem too.  */
+            re_set_syntax (RE_SYNTAX_EMACS | RE_ICASE);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("x", 1, &regex);
+            if (s)
+              result |= 16;
+            else if (re_search (&regex, "WXY", 3, 0, 3, &regs) < 0)
+              result |= 16;
+
+            /* Catch a bug reported by Vin Shelton in
+               
http://lists.gnu.org/archive/html/bug-coreutils/2007-06/msg00089.html
+               */
+            re_set_syntax (RE_SYNTAX_POSIX_BASIC
+                           & ~RE_CONTEXT_INVALID_DUP
+                           & ~RE_NO_EMPTY_RANGES);
+            memset (&regex, 0, sizeof regex);
+            s = re_compile_pattern ("[[:alnum:]_-]\\\\+$", 16, &regex);
+            if (s)
+              result |= 32;
+
+            /* REG_STARTEND was added to glibc on 2004-01-15.
+               Reject older versions.  */
+            if (! REG_STARTEND)
+              result |= 64;
+
+#if 0
+            /* It would be nice to reject hosts whose regoff_t values are too
+               narrow (including glibc on hosts with 64-bit ptrdiff_t and
+               32-bit int), but we should wait until glibc implements this
+               feature.  Otherwise, support for equivalence classes and
+               multibyte collation symbols would always be broken except
+               when compiling --without-included-regex.   */
+            if (sizeof (regoff_t) < sizeof (ptrdiff_t)
+                || sizeof (regoff_t) < sizeof (ssize_t))
+              result |= 64;
+#endif
+
+            return result;
+          ]])],
+       [gl_cv_func_re_compile_pattern_working=yes],
+       [gl_cv_func_re_compile_pattern_working=no],
+       dnl When crosscompiling, assume it is not working.
+       [gl_cv_func_re_compile_pattern_working=no])])
+    case $gl_cv_func_re_compile_pattern_working in #(
+    yes) ac_use_included_regex=no;; #(
+    no) ac_use_included_regex=yes;;
+    esac
+    ;;
+  *) AC_MSG_ERROR([Invalid value for --with-included-regex: 
$with_included_regex])
+    ;;
+  esac
+
+  if test $ac_use_included_regex = yes; then
+    AC_DEFINE([_REGEX_LARGE_OFFSETS], [1],
+      [Define if you want regoff_t to be at least as wide POSIX requires.])
+    AC_DEFINE([re_syntax_options], [rpl_re_syntax_options],
+      [Define to rpl_re_syntax_options if the replacement should be used.])
+    AC_DEFINE([re_set_syntax], [rpl_re_set_syntax],
+      [Define to rpl_re_set_syntax if the replacement should be used.])
+    AC_DEFINE([re_compile_pattern], [rpl_re_compile_pattern],
+      [Define to rpl_re_compile_pattern if the replacement should be used.])
+    AC_DEFINE([re_compile_fastmap], [rpl_re_compile_fastmap],
+      [Define to rpl_re_compile_fastmap if the replacement should be used.])
+    AC_DEFINE([re_search], [rpl_re_search],
+      [Define to rpl_re_search if the replacement should be used.])
+    AC_DEFINE([re_search_2], [rpl_re_search_2],
+      [Define to rpl_re_search_2 if the replacement should be used.])
+    AC_DEFINE([re_match], [rpl_re_match],
+      [Define to rpl_re_match if the replacement should be used.])
+    AC_DEFINE([re_match_2], [rpl_re_match_2],
+      [Define to rpl_re_match_2 if the replacement should be used.])
+    AC_DEFINE([re_set_registers], [rpl_re_set_registers],
+      [Define to rpl_re_set_registers if the replacement should be used.])
+    AC_DEFINE([re_comp], [rpl_re_comp],
+      [Define to rpl_re_comp if the replacement should be used.])
+    AC_DEFINE([re_exec], [rpl_re_exec],
+      [Define to rpl_re_exec if the replacement should be used.])
+    AC_DEFINE([regcomp], [rpl_regcomp],
+      [Define to rpl_regcomp if the replacement should be used.])
+    AC_DEFINE([regexec], [rpl_regexec],
+      [Define to rpl_regexec if the replacement should be used.])
+    AC_DEFINE([regerror], [rpl_regerror],
+      [Define to rpl_regerror if the replacement should be used.])
+    AC_DEFINE([regfree], [rpl_regfree],
+      [Define to rpl_regfree if the replacement should be used.])
+  fi
+])
+
+# Prerequisites of lib/regex.c and lib/regex_internal.c.
+AC_DEFUN([gl_PREREQ_REGEX],
+[
+  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+  AC_REQUIRE([AC_C_INLINE])
+  AC_REQUIRE([AC_C_RESTRICT])
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  AC_CHECK_HEADERS([libintl.h])
+  AC_CHECK_FUNCS_ONCE([isblank iswctype wcscoll])
+  AC_CHECK_DECLS([isblank], [], [], [[#include <ctype.h>]])
+])
diff --git a/m4/strcase.m4 b/m4/strcase.m4
new file mode 100644
index 0000000..717fa9c
--- /dev/null
+++ b/m4/strcase.m4
@@ -0,0 +1,45 @@
+# strcase.m4 serial 11
+dnl Copyright (C) 2002, 2005-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_STRCASE],
+[
+  gl_FUNC_STRCASECMP
+  gl_FUNC_STRNCASECMP
+])
+
+AC_DEFUN([gl_FUNC_STRCASECMP],
+[
+  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
+  AC_CHECK_FUNCS([strcasecmp])
+  if test $ac_cv_func_strcasecmp = no; then
+    HAVE_STRCASECMP=0
+  fi
+])
+
+AC_DEFUN([gl_FUNC_STRNCASECMP],
+[
+  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
+  AC_CHECK_FUNCS([strncasecmp])
+  if test $ac_cv_func_strncasecmp = yes; then
+    HAVE_STRNCASECMP=1
+  else
+    HAVE_STRNCASECMP=0
+  fi
+  AC_CHECK_DECLS([strncasecmp])
+  if test $ac_cv_have_decl_strncasecmp = no; then
+    HAVE_DECL_STRNCASECMP=0
+  fi
+])
+
+# Prerequisites of lib/strcasecmp.c.
+AC_DEFUN([gl_PREREQ_STRCASECMP], [
+  :
+])
+
+# Prerequisites of lib/strncasecmp.c.
+AC_DEFUN([gl_PREREQ_STRNCASECMP], [
+  :
+])
diff --git a/m4/strings_h.m4 b/m4/strings_h.m4
new file mode 100644
index 0000000..a057e1c
--- /dev/null
+++ b/m4/strings_h.m4
@@ -0,0 +1,52 @@
+# Configure a replacement for <strings.h>.
+# serial 6
+
+# Copyright (C) 2007, 2009-2012 Free Software Foundation, Inc.
+# This file is free software; the Free Software Foundation
+# gives unlimited permission to copy and/or distribute it,
+# with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_HEADER_STRINGS_H],
+[
+  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
+  dnl once only, before all statements that occur in other macros.
+  AC_REQUIRE([gl_HEADER_STRINGS_H_BODY])
+])
+
+AC_DEFUN([gl_HEADER_STRINGS_H_BODY],
+[
+  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
+
+  gl_CHECK_NEXT_HEADERS([strings.h])
+  if test $ac_cv_header_strings_h = yes; then
+    HAVE_STRINGS_H=1
+  else
+    HAVE_STRINGS_H=0
+  fi
+  AC_SUBST([HAVE_STRINGS_H])
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+    /* Minix 3.1.8 has a bug: <sys/types.h> must be included before
+       <strings.h>.  */
+    #include <sys/types.h>
+    #include <strings.h>
+    ]], [ffs strcasecmp strncasecmp])
+])
+
+AC_DEFUN([gl_STRINGS_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+])
+
+AC_DEFUN([gl_HEADER_STRINGS_H_DEFAULTS],
+[
+  GNULIB_FFS=0;            AC_SUBST([GNULIB_FFS])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_FFS=1;              AC_SUBST([HAVE_FFS])
+  HAVE_STRCASECMP=1;       AC_SUBST([HAVE_STRCASECMP])
+  HAVE_DECL_STRNCASECMP=1; AC_SUBST([HAVE_DECL_STRNCASECMP])
+])
diff --git a/m4/wcrtomb.m4 b/m4/wcrtomb.m4
new file mode 100644
index 0000000..00d7302
--- /dev/null
+++ b/m4/wcrtomb.m4
@@ -0,0 +1,112 @@
+# wcrtomb.m4 serial 11
+dnl Copyright (C) 2008-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_FUNC_WCRTOMB],
+[
+  AC_REQUIRE([gl_WCHAR_H_DEFAULTS])
+
+  AC_REQUIRE([AC_TYPE_MBSTATE_T])
+  gl_MBSTATE_T_BROKEN
+
+  AC_CHECK_FUNCS_ONCE([wcrtomb])
+  if test $ac_cv_func_wcrtomb = no; then
+    HAVE_WCRTOMB=0
+    AC_CHECK_DECLS([wcrtomb],,, [[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+]])
+    if test $ac_cv_have_decl_wcrtomb = yes; then
+      dnl On Minix 3.1.8, the system's <wchar.h> declares wcrtomb() although
+      dnl it does not have the function. Avoid a collision with gnulib's
+      dnl replacement.
+      REPLACE_WCRTOMB=1
+    fi
+  else
+    if test $REPLACE_MBSTATE_T = 1; then
+      REPLACE_WCRTOMB=1
+    else
+      dnl On AIX 4.3, OSF/1 5.1 and Solaris 10, wcrtomb (NULL, 0, NULL) 
sometimes
+      dnl returns 0 instead of 1.
+      AC_REQUIRE([AC_PROG_CC])
+      AC_REQUIRE([gt_LOCALE_FR])
+      AC_REQUIRE([gt_LOCALE_FR_UTF8])
+      AC_REQUIRE([gt_LOCALE_JA])
+      AC_REQUIRE([gt_LOCALE_ZH_CN])
+      AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+      AC_CACHE_CHECK([whether wcrtomb return value is correct],
+        [gl_cv_func_wcrtomb_retval],
+        [
+          dnl Initial guess, used when cross-compiling or when no suitable 
locale
+          dnl is present.
+changequote(,)dnl
+          case "$host_os" in
+                                     # Guess no on AIX 4, OSF/1 and Solaris.
+            aix4* | osf* | solaris*) gl_cv_func_wcrtomb_retval="guessing no" ;;
+                                     # Guess yes otherwise.
+            *)                       gl_cv_func_wcrtomb_retval="guessing yes" 
;;
+          esac
+changequote([,])dnl
+          if test $LOCALE_FR != none || test $LOCALE_FR_UTF8 != none || test 
$LOCALE_JA != none || test $LOCALE_ZH_CN != none; then
+            AC_RUN_IFELSE(
+              [AC_LANG_SOURCE([[
+#include <locale.h>
+#include <string.h>
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#include <stddef.h>
+#include <stdio.h>
+#include <time.h>
+#include <wchar.h>
+int main ()
+{
+  int result = 0;
+  if (setlocale (LC_ALL, "$LOCALE_FR") != NULL)
+    {
+      if (wcrtomb (NULL, 0, NULL) != 1)
+        result |= 1;
+    }
+  if (setlocale (LC_ALL, "$LOCALE_FR_UTF8") != NULL)
+    {
+      if (wcrtomb (NULL, 0, NULL) != 1)
+        result |= 2;
+    }
+  if (setlocale (LC_ALL, "$LOCALE_JA") != NULL)
+    {
+      if (wcrtomb (NULL, 0, NULL) != 1)
+        result |= 4;
+    }
+  if (setlocale (LC_ALL, "$LOCALE_ZH_CN") != NULL)
+    {
+      if (wcrtomb (NULL, 0, NULL) != 1)
+        result |= 8;
+    }
+  return result;
+}]])],
+              [gl_cv_func_wcrtomb_retval=yes],
+              [gl_cv_func_wcrtomb_retval=no],
+              [:])
+          fi
+        ])
+      case "$gl_cv_func_wcrtomb_retval" in
+        *yes) ;;
+        *) REPLACE_WCRTOMB=1 ;;
+      esac
+    fi
+  fi
+])
+
+# Prerequisites of lib/wcrtomb.c.
+AC_DEFUN([gl_PREREQ_WCRTOMB], [
+  :
+])
diff --git a/m4/wctype_h.m4 b/m4/wctype_h.m4
new file mode 100644
index 0000000..a109383
--- /dev/null
+++ b/m4/wctype_h.m4
@@ -0,0 +1,211 @@
+# wctype_h.m4 serial 16
+
+dnl A placeholder for ISO C99 <wctype.h>, for platforms that lack it.
+
+dnl Copyright (C) 2006-2012 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl Written by Paul Eggert.
+
+AC_DEFUN([gl_WCTYPE_H],
+[
+  AC_REQUIRE([gl_WCTYPE_H_DEFAULTS])
+  AC_REQUIRE([AC_PROG_CC])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CHECK_FUNCS_ONCE([iswcntrl])
+  if test $ac_cv_func_iswcntrl = yes; then
+    HAVE_ISWCNTRL=1
+  else
+    HAVE_ISWCNTRL=0
+  fi
+  AC_SUBST([HAVE_ISWCNTRL])
+
+  AC_REQUIRE([AC_C_INLINE])
+
+  AC_REQUIRE([gt_TYPE_WINT_T])
+  if test $gt_cv_c_wint_t = yes; then
+    HAVE_WINT_T=1
+  else
+    HAVE_WINT_T=0
+  fi
+  AC_SUBST([HAVE_WINT_T])
+
+  gl_CHECK_NEXT_HEADERS([wctype.h])
+  if test $ac_cv_header_wctype_h = yes; then
+    if test $ac_cv_func_iswcntrl = yes; then
+      dnl Linux libc5 has an iswprint function that returns 0 for all 
arguments.
+      dnl The other functions are likely broken in the same way.
+      AC_CACHE_CHECK([whether iswcntrl works], [gl_cv_func_iswcntrl_works],
+        [
+          AC_RUN_IFELSE(
+            [AC_LANG_SOURCE([[
+               /* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
+                  included before <wchar.h>.
+                  BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
+                  must be included before <wchar.h>.  */
+               #include <stddef.h>
+               #include <stdio.h>
+               #include <time.h>
+               #include <wchar.h>
+               #include <wctype.h>
+               int main () { return iswprint ('x') == 0; }
+            ]])],
+            [gl_cv_func_iswcntrl_works=yes], [gl_cv_func_iswcntrl_works=no],
+            [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stdlib.h>
+                          #if __GNU_LIBRARY__ == 1
+                          Linux libc5 i18n is broken.
+                          #endif]], [])],
+              [gl_cv_func_iswcntrl_works=yes], [gl_cv_func_iswcntrl_works=no])
+            ])
+        ])
+    fi
+    HAVE_WCTYPE_H=1
+  else
+    HAVE_WCTYPE_H=0
+  fi
+  AC_SUBST([HAVE_WCTYPE_H])
+
+  if test "$gl_cv_func_iswcntrl_works" = no; then
+    REPLACE_ISWCNTRL=1
+  else
+    REPLACE_ISWCNTRL=0
+  fi
+  AC_SUBST([REPLACE_ISWCNTRL])
+
+  if test $HAVE_ISWCNTRL = 0 || test $REPLACE_ISWCNTRL = 1; then
+    dnl Redefine all of iswcntrl, ..., iswxdigit in <wctype.h>.
+    :
+  fi
+
+  if test $REPLACE_ISWCNTRL = 1; then
+    REPLACE_TOWLOWER=1
+  else
+    AC_CHECK_FUNCS([towlower])
+    if test $ac_cv_func_towlower = yes; then
+      REPLACE_TOWLOWER=0
+    else
+      AC_CHECK_DECLS([towlower],,,
+        [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
+             included before <wchar.h>.
+             BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
+             must be included before <wchar.h>.  */
+          #include <stddef.h>
+          #include <stdio.h>
+          #include <time.h>
+          #include <wchar.h>
+          #if HAVE_WCTYPE_H
+          # include <wctype.h>
+          #endif
+        ]])
+      if test $ac_cv_have_decl_towlower = yes; then
+        dnl On Minix 3.1.8, the system's <wctype.h> declares towlower() and
+        dnl towupper() although it does not have the functions. Avoid a
+        dnl collision with gnulib's replacement.
+        REPLACE_TOWLOWER=1
+      else
+        REPLACE_TOWLOWER=0
+      fi
+    fi
+  fi
+  AC_SUBST([REPLACE_TOWLOWER])
+
+  if test $HAVE_ISWCNTRL = 0 || test $REPLACE_TOWLOWER = 1; then
+    dnl Redefine towlower, towupper in <wctype.h>.
+    :
+  fi
+
+  dnl We assume that the wctype() and iswctype() functions exist if and only
+  dnl if the type wctype_t is defined in <wchar.h> or in <wctype.h> if that
+  dnl exists.
+  dnl HP-UX 11.00 declares all these in <wchar.h> and lacks <wctype.h>.
+  AC_CACHE_CHECK([for wctype_t], [gl_cv_type_wctype_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
+               included before <wchar.h>.
+               BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
+               must be included before <wchar.h>.  */
+            #include <stddef.h>
+            #include <stdio.h>
+            #include <time.h>
+            #include <wchar.h>
+            #if HAVE_WCTYPE_H
+            # include <wctype.h>
+            #endif
+            wctype_t a;
+          ]],
+          [[]])],
+       [gl_cv_type_wctype_t=yes],
+       [gl_cv_type_wctype_t=no])
+    ])
+  if test $gl_cv_type_wctype_t = no; then
+    HAVE_WCTYPE_T=0
+  fi
+
+  dnl We assume that the wctrans() and towctrans() functions exist if and only
+  dnl if the type wctrans_t is defined in <wctype.h>.
+  AC_CACHE_CHECK([for wctrans_t], [gl_cv_type_wctrans_t],
+    [AC_COMPILE_IFELSE(
+       [AC_LANG_PROGRAM(
+          [[/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be
+               included before <wchar.h>.
+               BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h>
+               must be included before <wchar.h>.  */
+            #include <stddef.h>
+            #include <stdio.h>
+            #include <time.h>
+            #include <wchar.h>
+            #include <wctype.h>
+            wctrans_t a;
+          ]],
+          [[]])],
+       [gl_cv_type_wctrans_t=yes],
+       [gl_cv_type_wctrans_t=no])
+    ])
+  if test $gl_cv_type_wctrans_t = no; then
+    HAVE_WCTRANS_T=0
+  fi
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Tru64 with Desktop Toolkit C has a bug: <stdio.h> must be included before
+   <wchar.h>.
+   BSD/OS 4.0.1 has a bug: <stddef.h>, <stdio.h> and <time.h> must be
+   included before <wchar.h>.  */
+#if !(defined __GLIBC__ && !defined __UCLIBC__)
+# include <stddef.h>
+# include <stdio.h>
+# include <time.h>
+# include <wchar.h>
+#endif
+#include <wctype.h>
+    ]],
+    [wctype iswctype wctrans towctrans
+    ])
+])
+
+AC_DEFUN([gl_WCTYPE_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_WCTYPE_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_WCTYPE_H_DEFAULTS],
+[
+  GNULIB_ISWBLANK=0;    AC_SUBST([GNULIB_ISWBLANK])
+  GNULIB_WCTYPE=0;      AC_SUBST([GNULIB_WCTYPE])
+  GNULIB_ISWCTYPE=0;    AC_SUBST([GNULIB_ISWCTYPE])
+  GNULIB_WCTRANS=0;     AC_SUBST([GNULIB_WCTRANS])
+  GNULIB_TOWCTRANS=0;   AC_SUBST([GNULIB_TOWCTRANS])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  HAVE_ISWBLANK=1;      AC_SUBST([HAVE_ISWBLANK])
+  HAVE_WCTYPE_T=1;      AC_SUBST([HAVE_WCTYPE_T])
+  HAVE_WCTRANS_T=1;     AC_SUBST([HAVE_WCTRANS_T])
+  REPLACE_ISWBLANK=0;   AC_SUBST([REPLACE_ISWBLANK])
+])
diff --git a/test-suite/tests/i18n.test b/test-suite/tests/i18n.test
index da23080..d1b0a54 100644
--- a/test-suite/tests/i18n.test
+++ b/test-suite/tests/i18n.test
@@ -138,11 +138,12 @@
   (under-locale-or-unresolved %french-utf8-locale thunk))
 
 (define (under-turkish-utf8-locale-or-unresolved thunk)
-  ;; FreeBSD 8.2 and Solaris 2.10 have a broken tr_TR locale where `i'
-  ;; is mapped to uppercase `I' instead of `Ä°', so disable tests on that
-  ;; platform.
+  ;; FreeBSD 8.2, Solaris 2.10, and Darwin 8.11.0 have a broken tr_TR
+  ;; locale where `i' is mapped to uppercase `I' instead of `Ä°', so
+  ;; disable tests on that platform.
   (if (or (string-contains %host-type "freebsd8")
-          (string-contains %host-type "solaris2.10"))
+          (string-contains %host-type "solaris2.10")
+          (string-contains %host-type "darwin8"))
       (throw 'unresolved)
       (under-locale-or-unresolved %turkish-utf8-locale thunk)))
 
diff --git a/test-suite/tests/net-db.test b/test-suite/tests/net-db.test
index 89ebb1b..edd87ce 100644
--- a/test-suite/tests/net-db.test
+++ b/test-suite/tests/net-db.test
@@ -1,7 +1,7 @@
 ;;;; net-db.test --- Test suite for `net-db' -*- mode: scheme; coding: utf-8; 
-*-
 ;;;; Ludovic Courtès <address@hidden>
 ;;;;
-;;;;   Copyright (C) 2010, 2011 Free Software Foundation, Inc.
+;;;;   Copyright (C) 2010, 2011, 2012 Free Software Foundation, Inc.
 ;;;;
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -100,7 +100,11 @@
                 #f))
           (lambda (key errcode)
             ;; According to POSIX, both error codes are valid (glibc 2.11
-            ;; chooses `EAI_SERVICE'; Darwin chooses `EAI_NONAME'.)
+            ;; chooses `EAI_SERVICE'; Darwin 8.11.0 chooses the non-POSIX
+            ;; `EAI_NODATA', and more recent Darwin versions choose
+            ;; `EAI_NONAME'.)
             (and (or (= errcode EAI_SERVICE)
-                     (= errcode EAI_NONAME))
+                     (= errcode EAI_NONAME)
+                     (and (defined? 'EAI_NODATA)
+                          (= errcode EAI_NODATA)))
                  (string? (gai-strerror errcode))))))))


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