[PATCH 3/4] maint: pick XSI funcs at runtime, not configure time.

[Gary V. Vaughan]

Determine, on a function by function basis, what XSI features
are available in the shell that is actually running the script,
rather than the one that was picked at configure time by the
re-execution engine.
* m4/libtool.m4 (_LT_PROG_FUNCTION_REPLACE)
(_LT_PROG_REPLACE_SHELLFNS): Remove.
(_LT_CHECK_SHELL_FEATURES): Remove tests for XSI and += support.
* build-aux/general.m4sh (func_append, func_append_quoted)
(func_arith, func_len, func_basename, func_dirname)
(func_dirname_and_basename, func_stripname): List both enhanced
and fallback implementations, and choose one based on whether
the enhanced features required by the fastest version are
available.
* build-aux/getopt.m4sh (func_split_short_opt)
(func_split_long_opt): Ditto.
* build-aux/ltmain.m4sh (func_lo2o, func_xform): Ditto.
* tests/getopt-m4sh.at: Add tests for enhanced and fallback
implementations of func_arith, func_len, func_stripname and
func_dirname_and_basename.
* NEWS: Updated.

Signed-off-by: Gary V. Vaughan <address@hidden>
---
 NEWS                   |    4 +
 build-aux/general.m4sh |  162 ++++++++++++++++++++++++++++++++---------------
 build-aux/getopt.m4sh  |   38 ++++++++++--
 build-aux/ltmain.m4sh  |   33 ++++++++--
 m4/libtool.m4          |  117 +----------------------------------
 tests/getopt-m4sh.at   |  116 ++++++++++++++++++++++++----------
 6 files changed, 256 insertions(+), 214 deletions(-)

diff --git a/NEWS b/NEWS
index 0479a34..ecd4fa1 100644
--- a/NEWS
+++ b/NEWS
@@ -49,6 +49,10 @@ NEWS - list of user-visible changes between releases of GNU 
Libtool
     mode is selected; `--standalone' never worked, and is no longer
     accepted.
   - Libtool and libtoolize no longer choke on paths with a comma in them.
+  - In the case where $SHELL does not have the same enhanced features
+    (e.g. the ability to parse `var+=append') as $CONFIG_SHELL, libtool
+    will now correctly fallback to using only vanilla shell features
+    instead of failing with a parse at startup.
 
 ** Important incompatible changes:
 
diff --git a/build-aux/general.m4sh b/build-aux/general.m4sh
index eeda222..648315d 100644
--- a/build-aux/general.m4sh
+++ b/build-aux/general.m4sh
@@ -73,63 +73,114 @@ IFS="       $lt_nl"
 dirname='s|/[^/]*$||'
 basename='s|^.*/||'
 
-
-# func_append var value
-# Append VALUE to the end of shell variable VAR.
-func_append ()
-{
+: ${_use_fast_funcs=":"}
+
+if $_use_fast_funcs && (eval 'x=a; x+=" b"; test "a b" = "$x"') 2>/dev/null
+then
+  # func_append var value
+  # Append VALUE to the end of shell variable VAR.
+  eval 'func_append ()
+  {
+    eval "$1+=\$2"
+  }'
+
+  # func_append_quoted var value
+  # Quote VALUE and append to the end of shell variable VAR, separated
+  # by a space.
+  eval 'func_append_quoted ()
+  {
+    func_quote_for_eval "$2"
+    eval "$1+=\\ \$func_quote_for_eval_result"
+  }'
+else
+  func_append ()
+  {
     eval "$1=\$$1\$2"
-} # func_append may be replaced by extended shell implementation
+  }
 
-
-# func_append_quoted var value
-# Quote VALUE and append to the end of shell variable VAR, separated
-# by a space.
-func_append_quoted ()
-{
+  func_append_quoted ()
+  {
     func_quote_for_eval "$2"
     eval "$1=\$$1\\ \$func_quote_for_eval_result"
-} # func_append_quoted may be replaced by extended shell implementation
+  }
+fi
 
 
 # func_arith arithmetic-term...
-func_arith ()
-{
+if $_use_fast_funcs && (eval 'x=$(( 1 + 1 )); test 2 = "$x"') 2>/dev/null
+then
+  eval 'func_arith ()
+  {
+    func_arith_result=$(( $* ))
+  }'
+else
+  func_arith ()
+  {
     func_arith_result=`expr "$@"`
-} # func_arith may be replaced by extended shell implementation
+  }
+fi
 
 
 # func_len string
 # STRING may not start with a hyphen.
-func_len ()
-{
+if $_use_fast_funcs && (eval 'x=12; test 2 = "${#x}"') 2>/dev/null
+then
+  eval 'func_len ()
+  {
+    func_len_result=${#1}
+  }'
+else
+  func_len ()
+  {
     func_len_result=`expr "$1" : ".*" 2>/dev/null || echo $max_cmd_len`
-} # func_len may be replaced by extended shell implementation
+  }
+fi
 
 
-# func_dirname file append nondir_replacement
-# Compute the dirname of FILE.  If nonempty, add APPEND to the result,
-# otherwise set result to NONDIR_REPLACEMENT.
-func_dirname ()
-{
-    func_dirname_result=`$ECHO "$1" | $SED "$dirname"`
-    if test "X$func_dirname_result" = "X$1"; then
-      func_dirname_result=$3
-    else
-      func_append func_dirname_result $2
-    fi
-} # func_dirname may be replaced by extended shell implementation
+if $_use_fast_funcs \
+    && (eval 'x=a/x/b; a=${x%/*}; b=${x##*/}; test ba/x = "$a$b"') 2>/dev/null
+then
+  # If this shell supports suffix pattern removal, then use it to avoid
+  # forking. Hide the definitions single quotes in case the shell chokes
+  # on unsupported syntax...
+
+  _b='func_basename_result=${1##*/}'
+  _d='case $1 in
+        */*) func_dirname_result=${1%/*}$2 ;;
+        *  ) func_dirname_result=$3        ;;
+      esac'
+
+else
+  # ...otherwise fall back to using sed.
+
+  _b='func_basename_result=`$ECHO "$1" |$SED "$basename"`'
+  _d='func_dirname_result=`$ECHO "$1"  |$SED "$dirname"`
+      if test "X$func_dirname_result" = "X$1"; then
+        func_dirname_result=$3
+      else
+        func_append func_dirname_result "$2"
+      fi'
+fi
 
 
 # func_basename file
-func_basename ()
+eval 'func_basename ()
 {
-    func_basename_result=`$ECHO "$1" | $SED "$basename"`
-} # func_basename may be replaced by extended shell implementation
+    $debug_cmd
+    '"$_b"'
+}'
 
+# func_dirname file append nondir_replacement
+# Compute the dirname of FILE.  If nonempty, add APPEND to the result,
+# otherwise set result to NONDIR_REPLACEMENT.
+eval 'func_dirname ()
+{
+    $debug_cmd
+    '"$_d"'
+}'
 
-# func_dirname_and_basename file append nondir_replacement
-# perform func_basename and func_dirname in a single function
+# func_dirname_and_basename file append nondir_replacement perform
+# func_basename and func_dirname in a single function
 # call:
 #   dirname:  Compute the dirname of FILE.  If nonempty,
 #             add APPEND to the result, otherwise set result
@@ -137,20 +188,14 @@ func_basename ()
 #             value returned in "$func_dirname_result"
 #   basename: Compute filename of FILE.
 #             value retuned in "$func_basename_result"
-# Implementation must be kept synchronized with func_dirname
-# and func_basename. For efficiency, we do not delegate to
-# those functions but instead duplicate the functionality here.
-func_dirname_and_basename ()
+# For efficiency, we do not delegate to the functions above but instead
+# duplicate the functionality here.
+eval 'func_dirname_and_basename ()
 {
-    # Extract subdirectory from the argument.
-    func_dirname_result=`$ECHO "$1" | $SED -e "$dirname"`
-    if test "X$func_dirname_result" = "X$1"; then
-      func_dirname_result=$3
-    else
-      func_append func_dirname_result $2
-    fi
-    func_basename_result=`$ECHO "$1" | $SED -e "$basename"`
-} # func_dirname_and_basename may be replaced by extended shell implementation
+    $debug_cmd
+    '"$_b"'
+    '"$_d"'
+}'
 
 
 # func_stripname prefix suffix name
@@ -159,13 +204,26 @@ func_dirname_and_basename ()
 # characters, hashes, percent signs, but SUFFIX may contain a leading
 # dot (in which case that matches only a dot).
 # func_strip_suffix prefix name
-func_stripname ()
-{
+if $_use_fast_funcs \
+    &&(eval 'x=p/x.s; x=${x#.s}; x=${x%p/}; test x = "$x"') 2>/dev/null
+then
+  eval 'func_stripname ()
+  {
+    # pdksh 5.2.14 does not do ${X%$Y} correctly if both X and Y are
+    # positional parameters, so assign one to ordinary variable first.
+    func_stripname_result=$3
+    func_stripname_result=${func_stripname_result#"$1"}
+    func_stripname_result=${func_stripname_result%"$2"}
+  }'
+else
+  func_stripname ()
+  {
     case $2 in
       .*) func_stripname_result=`$ECHO "$3" | $SED "s%^$1%%; s%\\\\$2\$%%"`;;
       *)  func_stripname_result=`$ECHO "$3" | $SED "s%^$1%%; s%$2\$%%"`;;
     esac
-} # func_stripname may be replaced by extended shell implementation
+  }
+fi
 
 
 # These SED scripts presuppose an absolute path with a trailing slash.
diff --git a/build-aux/getopt.m4sh b/build-aux/getopt.m4sh
index 27a8352..4d7e9ff 100644
--- a/build-aux/getopt.m4sh
+++ b/build-aux/getopt.m4sh
@@ -621,27 +621,53 @@ func_missing_arg ()
 # func_split_short_opt shortopt
 # Set func_split_short_opt_name and func_split_short_opt_arg shell
 # variables after splitting SHORTOPT after the 2nd character.
-func_split_short_opt ()
-{
+if (eval 'x=ab; b=${x#?}; a=${x%"$b"}; test ba = "$b$a"') 2>/dev/null
+then
+  # If this shell supports prefix and suffix pattern removal, then
+  # use them to avoid forking. Hide the definition in an eval in case
+  # the shell chokes on unsupported syntax...
+  eval 'func_split_short_opt ()
+  {
+    $debug_cmd
+
+    func_split_short_opt_arg=${1#??}
+    func_split_short_opt_name=${1%"$func_split_short_opt_arg"}
+  }'
+else
+  # ...otherwise fall back to using sed.
+  func_split_short_opt ()
+  {
     my_sed_short_opt='1s/^\(..\).*$/\1/;q'
     my_sed_short_rest='1s/^..\(.*\)$/\1/;q'
 
     func_split_short_opt_name=`$ECHO "$1" | $SED "$my_sed_short_opt"`
     func_split_short_opt_arg=`$ECHO "$1" | $SED "$my_sed_short_rest"`
-} # func_split_short_opt may be replaced by extended shell implementation
+  }
+fi
 
 
 # func_split_long_opt longopt
 # Set func_split_long_opt_name and func_split_long_opt_arg shell
 # variables after splitting LONGOPT at the `=' sign.
-func_split_long_opt ()
-{
+if (eval 'x=aa=bb; a=${x%%=*}; b=${x#*=}; test bbaa = "$b$a"') 2>/dev/null
+then
+  # Faster implementation if this shell supports it...
+  eval 'func_split_long_opt ()
+  {
+    func_split_long_opt_name=${1%%=*}
+    func_split_long_opt_arg=${1#*=}
+  }'
+else
+  # ...otherwise fall back to using sed.
+  func_split_long_opt ()
+  {
     my_sed_long_opt='1s/^\(--[^=]*\)=.*/\1/;q'
     my_sed_long_arg='1s/^--[^=]*=//'
 
     func_split_long_opt_name=`$ECHO "$1" | $SED "$my_sed_long_opt"`
     func_split_long_opt_arg=`$ECHO "$1" | $SED "$my_sed_long_arg"`
-} # func_split_long_opt may be replaced by extended shell implementation
+  }
+fi
 
 exit_cmd=:
 ]])
diff --git a/build-aux/ltmain.m4sh b/build-aux/ltmain.m4sh
index b88c984..4a0b132 100644
--- a/build-aux/ltmain.m4sh
+++ b/build-aux/ltmain.m4sh
@@ -150,17 +150,36 @@ exec_cmd=
 
 
 # func_lo2o object
-func_lo2o ()
-{
+if (eval 'x=a/b.xx; test a/b.c = "${x%.xx}.c"') 2>/dev/null
+then
+  eval 'func_lo2o ()
+  {
+    case $1 in
+      *.lo) func_lo2o_result=${1%.lo}.$objext ;;
+      *   ) func_lo2o_result=$1               ;;
+    esac
+  }'
+else
+  func_lo2o ()
+  {
     func_lo2o_result=`$ECHO "$1" | $SED "$lo2o"`
-} # func_lo2o may be replaced by extended shell implementation
+  }
+fi
 
 
 # func_xform libobj-or-source
-func_xform ()
-{
-    func_xform_result=`$ECHO "$1" | $SED 's/\.[^.]*$/.lo/'`
-} # func_xform may be replaced by extended shell implementation
+if (eval 'x=a/b.xx; test a/b.c = "${x%.*}.c"') 2>/dev/null
+then
+  eval 'func_xform ()
+  {
+    func_xform_result=${1%.*}.lo
+  }'
+else
+  func_xform ()
+  {
+    func_xform_result=`$ECHO "$1" | $SED 's|\.[^.]*$|.lo|'`
+  }
+fi
 
 
 # func_fatal_configuration arg...
diff --git a/m4/libtool.m4 b/m4/libtool.m4
index 007492c..ede8319 100644
--- a/m4/libtool.m4
+++ b/m4/libtool.m4
@@ -756,8 +756,6 @@ _LT_EOF
   sed '$q' "$ltmain" >> "$cfgfile" \
      || (rm -f "$cfgfile"; exit 1)
 
-  _LT_PROG_REPLACE_SHELLFNS
-
    mv -f "$cfgfile" "$ofile" ||
     (rm -f "$ofile" && cp "$cfgfile" "$ofile" && rm -f "$cfgfile")
   chmod +x "$ofile"
@@ -7776,27 +7774,7 @@ dnl AC_DEFUN([LT_AC_PROG_SED], [])
 # Find out whether the shell is Bourne or XSI compatible,
 # or has some other useful features.
 m4_defun([_LT_CHECK_SHELL_FEATURES],
-[AC_MSG_CHECKING([whether the shell understands some XSI constructs])
-# Try some XSI features
-xsi_shell=no
-( _lt_dummy=a/b/c
-  test 
"${_lt_dummy##*/},${_lt_dummy%/*},${_lt_dummy#??}"${_lt_dummy%"$_lt_dummy"}, \
-      = c,a/b,b/c, \
-    && eval 'test 2 -eq $(( 1 + 1 )) \
-    && test "${#_lt_dummy}" -eq 5' ) >/dev/null 2>&1 \
-  && xsi_shell=yes
-AC_MSG_RESULT([$xsi_shell])
-_LT_CONFIG_LIBTOOL_INIT([xsi_shell='$xsi_shell'])
-
-AC_MSG_CHECKING([whether the shell understands "+="])
-lt_shell_append=no
-( foo=bar; set foo baz; eval "$[1]+=\$[2]" && test "$foo" = barbaz ) \
-    >/dev/null 2>&1 \
-  && lt_shell_append=yes
-AC_MSG_RESULT([$lt_shell_append])
-_LT_CONFIG_LIBTOOL_INIT([lt_shell_append='$lt_shell_append'])
-
-if ( (MAIL=60; unset MAIL) || exit) >/dev/null 2>&1; then
+[if ( (MAIL=60; unset MAIL) || exit) >/dev/null 2>&1; then
   lt_unset=unset
 else
   lt_unset=false
@@ -7820,99 +7798,6 @@ _LT_DECL([NL2SP], [lt_NL2SP], [1], [turn newlines into 
spaces])dnl
 ])# _LT_CHECK_SHELL_FEATURES
 
 
-# _LT_PROG_FUNCTION_REPLACE (FUNCNAME, REPLACEMENT-BODY)
-# ------------------------------------------------------
-# In `$cfgfile', look for function FUNCNAME delimited by `^FUNCNAME ()$' and
-# '^} FUNCNAME ', and replace its body with REPLACEMENT-BODY.
-m4_defun([_LT_PROG_FUNCTION_REPLACE],
-[dnl {
-sed -e '/^$1 ()$/,/^} # $1 /c\
-$1 ()\
-{\
-m4_bpatsubsts([$2], [$], [\\], [^\([    ]\)], [\\\1])
-} # Extended-shell $1 implementation' "$cfgfile" > $cfgfile.tmp \
-  && mv -f "$cfgfile.tmp" "$cfgfile" \
-    || (rm -f "$cfgfile" && cp "$cfgfile.tmp" "$cfgfile" && rm -f 
"$cfgfile.tmp")
-test 0 -eq $? || _lt_function_replace_fail=:
-])
-
-
-# _LT_PROG_REPLACE_SHELLFNS
-# -------------------------
-# Replace existing portable implementations of several shell functions with
-# equivalent extended shell implementations where those features are 
available..
-m4_defun([_LT_PROG_REPLACE_SHELLFNS],
-[if test x"$xsi_shell" = xyes; then
-  _LT_PROG_FUNCTION_REPLACE([func_dirname], [dnl
-    case @S|@1 in
-      */*) func_dirname_result=${1%/address@hidden|@2 ;;
-      *  ) address@hidden|@3 ;;
-    esac])
-
-  _LT_PROG_FUNCTION_REPLACE([func_basename], [dnl
-    func_basename_result=${1##*/}])
-
-  _LT_PROG_FUNCTION_REPLACE([func_dirname_and_basename], [dnl
-    case @S|@1 in
-      */*) func_dirname_result=${1%/address@hidden|@2 ;;
-      *  ) address@hidden|@3 ;;
-    esac
-    func_basename_result=${1##*/}])
-
-  _LT_PROG_FUNCTION_REPLACE([func_stripname], [dnl
-    # pdksh 5.2.14 does not do ${X%$Y} correctly if both X and Y are
-    # positional parameters, so assign one to ordinary parameter first.
-    address@hidden|@3
-    func_stripname_result=${func_stripname_result#"@S|@1"}
-    func_stripname_result=${func_stripname_result%"@S|@2"}])
-
-  _LT_PROG_FUNCTION_REPLACE([func_split_long_opt], [dnl
-    func_split_long_opt_name=${1%%=*}
-    func_split_long_opt_arg=${1#*=}])
-
-  _LT_PROG_FUNCTION_REPLACE([func_split_short_opt], [dnl
-    func_split_short_opt_arg=${1#??}
-    func_split_short_opt_name=${1%"$func_split_short_opt_arg"}])
-
-  _LT_PROG_FUNCTION_REPLACE([func_lo2o], [dnl
-    case @S|@1 in
-      *.lo) func_lo2o_result=${1%.lo}.$objext ;;
-      *)    address@hidden|@1 ;;
-    esac])
-
-  _LT_PROG_FUNCTION_REPLACE([func_xform], [    func_xform_result=${1%.*}.lo])
-
-  _LT_PROG_FUNCTION_REPLACE([func_arith], [    func_arith_result=$(( $[*] ))])
-
-  _LT_PROG_FUNCTION_REPLACE([func_len], [    func_len_result=${#1}])
-fi
-
-if test x"$lt_shell_append" = xyes; then
-  _LT_PROG_FUNCTION_REPLACE([func_append], [    eval "@S|@address@hidden|@2"])
-
-  _LT_PROG_FUNCTION_REPLACE([func_append_quoted], [dnl
-    func_quote_for_eval "@S|@2"
-dnl m4 expansion turns \\\\ into \\, and then the shell eval turns that into \
-    eval "@S|@1+=\\\\ \\$func_quote_for_eval_result"])
-
-  # Save a `func_append' function call where possible by direct use of '+='
-  sed -e 's%func_append \([[a-zA-Z_]]\{1,\}\) "%\1+="%g' $cfgfile > 
$cfgfile.tmp \
-    && mv -f "$cfgfile.tmp" "$cfgfile" \
-      || (rm -f "$cfgfile" && cp "$cfgfile.tmp" "$cfgfile" && rm -f 
"$cfgfile.tmp")
-  test 0 -eq $? || _lt_function_replace_fail=:
-else
-  # Save a `func_append' function call even when '+=' is not available
-  sed -e 's%func_append \([[a-zA-Z_]]\{1,\}\) "%\1="$\1%g' $cfgfile > 
$cfgfile.tmp \
-    && mv -f "$cfgfile.tmp" "$cfgfile" \
-      || (rm -f "$cfgfile" && cp "$cfgfile.tmp" "$cfgfile" && rm -f 
"$cfgfile.tmp")
-  test 0 -eq $? || _lt_function_replace_fail=:
-fi
-
-if test x"$_lt_function_replace_fail" = x":"; then
-  AC_MSG_WARN([Unable to substitute extended shell functions in $ofile])
-fi
-])
-
 # _LT_PATH_CONVERSION_FUNCTIONS
 # -----------------------------
 # Determine which file name conversion functions should be used by
diff --git a/tests/getopt-m4sh.at b/tests/getopt-m4sh.at
index 81160db..6b50edc 100644
--- a/tests/getopt-m4sh.at
+++ b/tests/getopt-m4sh.at
@@ -40,9 +40,22 @@ M4SH_GETOPTS(
   [a!],        [--append],     [],     [func_append list "$optarg$nl"],
   [f], [--force],      [],     [opts="$opts force"],
   [i], [--install],    [],     [opts="$opts install"],
+  [l;],        [--length],     [],     [],
+  [p!],        [--path],       [],     [func_dirname_and_basename "$optarg"],
   [v], [--verbose],    [],     [opts="$opts verbose"],
   [!], [--ltdl],       [false],[opts="$opts ltdl=$optarg"],
-[echo "$list" $opts])
+[test -z "$opt_length" || {
+  for s in $opt_length; do
+    func_len "$s"
+    func_arith ${len-0} + $func_len_result; len=$func_arith_result
+  done
+  echo len=$len
+}
+test -z "$opt_path" || {
+  func_stripname b_ .d "$func_basename_result"
+  echo "$func_dirname_result:$func_stripname_result"
+}
+test -z "$list$opts" || echo "$list" $opts])
 ]])
 m4_pattern_forbid([m4_include])
 m4_pattern_forbid([AS_INIT])
@@ -53,22 +66,11 @@ $SED "s|@LN_S\@|$LN_S|g;s|@SED\@|$SED|g" t-options > options
 ])# _LT_AT_GETOPT_M4SH_SETUP
 
 
-# _LT_AT_EXTENDED_SHELL_FUNC_EXTRACT(FUNC-NAME)
-# ---------------------------------------------
-# Extract the 'Extended-shell'-decorated function FUNC-NAME from libtool
-m4_define([_LT_AT_XSI_FUNC_EXTRACT],
-[dnl {{
-$SED '/^# $1/q' options > options.tmp
-$SED -n '/^$1 ()/,/^} # Extended-shell $1 /p' $abs_top_builddir/libtool >> 
options.tmp
-$SED '1,/^} # $1 /d' options >> options.tmp
-rm -f options && mv options.tmp options])
-
-
 ## ----------------------- ##
 ## Short option splitting. ##
 ## ----------------------- ##
 
-AT_SETUP([short option splitting])
+AT_SETUP([fallback short option splitting])
 
 AT_DATA(expout,
 [[ force verbose install
@@ -76,22 +78,18 @@ AT_DATA(expout,
 
 _LT_AT_GETOPT_M4SH_SETUP
 
-AT_CHECK([$SHELL ./options -fvi], 0, [expout])
+AT_CHECK([_use_fast_funcs=false $SHELL ./options -fvi], 0, [expout])
 
 AT_CLEANUP
 
 
-AT_SETUP([enhanced shell short option splitting])
-
-# Don't bother with additional XSI checks unless functions were substituted
-AT_CHECK([fgrep '@%:@ Extended-shell func_split_short_opt' 
$abs_top_builddir/libtool >/dev/null 2>&1 || (exit 77)])
+AT_SETUP([enhanced short option splitting])
 
 AT_DATA(expout,
 [[ force verbose install
 ]])
 
 _LT_AT_GETOPT_M4SH_SETUP
-_LT_AT_XSI_FUNC_EXTRACT(func_split_short_opt)
 
 AT_CHECK([$SHELL ./options -fvi], 0, [expout])
 
@@ -102,7 +100,7 @@ AT_CLEANUP
 ## Long option splitting. ##
 ## ---------------------- ##
 
-AT_SETUP([long option splitting])
+AT_SETUP([fallback long option splitting])
 
 AT_DATA(expout,
 [[ ltdl=long
@@ -110,22 +108,18 @@ AT_DATA(expout,
 
 _LT_AT_GETOPT_M4SH_SETUP
 
-AT_CHECK([$SHELL ./options --ltdl=long], 0, [expout])
+AT_CHECK([_use_fast_funcs=false $SHELL ./options --ltdl=long], 0, [expout])
 
 AT_CLEANUP
 
 
-AT_SETUP([XSI long option splitting])
-
-# Don't bother with additional XSI checks unless functions were substituted
-AT_CHECK([fgrep '@%:@ Extended-shell func_split_long_opt' 
$abs_top_builddir/libtool >/dev/null 2>&1 || (exit 77)])
+AT_SETUP([enhanced long option splitting])
 
 AT_DATA(expout,
 [[ ltdl=long
 ]])
 
 _LT_AT_GETOPT_M4SH_SETUP
-_LT_AT_XSI_FUNC_EXTRACT(func_split_long_opt)
 
 AT_CHECK([$SHELL ./options --ltdl=long], 0, [expout])
 
@@ -136,7 +130,7 @@ AT_CLEANUP
 ## Option appending. ##
 ## ----------------- ##
 
-AT_SETUP([option appending])
+AT_SETUP([fallback option appending])
 
 AT_DATA(expout,
 [[first   --append second
@@ -146,15 +140,12 @@ third
 
 _LT_AT_GETOPT_M4SH_SETUP
 
-AT_CHECK([$SHELL ./options -a "first   --append second" -athird], 0, [expout])
+AT_CHECK([_use_fast_funcs=false $SHELL ./options -a "first   --append second" 
-athird], 0, [expout])
 
 AT_CLEANUP
 
 
-AT_SETUP([enhanced shell option appending])
-
-# Don't bother with additional += check unless functions were substituted
-AT_CHECK([fgrep '@%:@ Extended-shell func_append ' $abs_top_builddir/libtool 
>/dev/null 2>&1 || (exit 77)])
+AT_SETUP([enhanced option appending])
 
 AT_DATA(expout,
 [[first   --append second
@@ -163,8 +154,67 @@ third
 ]])
 
 _LT_AT_GETOPT_M4SH_SETUP
-_LT_AT_XSI_FUNC_EXTRACT(func_append)
 
 AT_CHECK([$SHELL ./options -a "first   --append second" -athird], 0, [expout])
 
 AT_CLEANUP
+
+
+## ----------------- ##
+## Shell arithmetic. ##
+## ----------------- ##
+
+AT_SETUP([fallback arithmetic])
+
+AT_DATA(expout,
+[[len=9
+]])
+
+_LT_AT_GETOPT_M4SH_SETUP
+
+AT_CHECK([_use_fast_funcs=false $SHELL ./options -l short --length long], 0, 
[expout])
+
+AT_CLEANUP
+
+
+AT_SETUP([enhanced arithmetic])
+
+AT_DATA(expout,
+[[len=9
+]])
+
+_LT_AT_GETOPT_M4SH_SETUP
+
+AT_CHECK([$SHELL ./options -l short --length long], 0, [expout])
+
+AT_CLEANUP
+
+
+## ------------- ##
+## Path slicing. ##
+## ------------- ##
+
+AT_SETUP([fallback path slicing])
+
+AT_DATA(expout,
+[[a:c
+]])
+
+_LT_AT_GETOPT_M4SH_SETUP
+
+AT_CHECK([_use_fast_funcs=false $SHELL ./options -p a/b_c.d], 0, [expout])
+
+AT_CLEANUP
+
+
+AT_SETUP([enhanced path slicing])
+
+AT_DATA(expout,
+[[a:c
+]])
+
+_LT_AT_GETOPT_M4SH_SETUP
+
+AT_CHECK([$SHELL ./options -p a/b_c.d], 0, [expout])
+
+AT_CLEANUP
-- 
1.7.7.4

Cheers,
-- 
Gary V. Vaughan (gary AT gnu DOT org)