[PATCH v2 2/9] build: refactor how lists of coreutils programs are defined

[Stefano Lattarini]

This is in preparation of future changes.  Still, this patch
leaves the build system in a better shape; true, with more
indirections, but also with less convoluted and brittle hacks.

Unfortunately, this commit also makes some rebuild rules
incomplete; that will son be fixed by follow-up patches.

* build-aux/gen-lists-of-programs.sh: New, generates autoconf
and automake input fragments that define "lists" of all coreutils
programs, with further distinctions about how and when these
programs should be built (by default; if the system is capable
enough; only if the user ask for them explicitly).  This is
useful to avoid duplicating the definitions of these list among
several files (at least 'configure.ac' 'src/Makefile.am'); such
duplication had proved a source of inconsistencies and bugs in
the past.  And the pre-existing way to avoid such duplication,
as implemented in 'configure.ac' before this patch, was overly
complex and brittle.
* Makefile.am (EXTRA_DIST): Distribute the new script.
* bootstrap.conf (bootstrap_post_import_hook): Run the new script
to generate 'm4/cu-progs.m4' and 'src/cu-progs.mk'.
* .gitignore: Ignore those files.
* configure.ac: Include 'm4/cu-progs.m4', and decidedly simplify
most of the programs' lists definition and processing accordingly.
* src/Makefile.am: Similarly include 'src/cu-progs.mk', containing
definition of variables $(default__progs), $(no_install__progs)
and $(build_if_possible__progs). Accordingly ...
(no_install__progs, build_if_possible__progs): ... remove.
(EXTRA_DIST): Adjust definition.
Adjust a comment.
---
 .gitignore                         |   2 +
 Makefile.am                        |   1 +
 bootstrap.conf                     |   6 +-
 build-aux/gen-lists-of-programs.sh | 186 +++++++++++++++++++++++++++++++++++++
 configure.ac                       |  62 ++-----------
 src/Makefile.am                    | 125 ++-----------------------
 6 files changed, 212 insertions(+), 170 deletions(-)
 create mode 100755 build-aux/gen-lists-of-programs.sh

diff --git a/.gitignore b/.gitignore
index aad59bd..56a9bf4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -96,6 +96,7 @@
 /m4/.cvsignore
 /m4/.gitignore
 /m4/codeset.m4
+/m4/cu-progs.m4
 /m4/fcntl-o.m4
 /m4/gettext.m4
 /m4/glibc2.m4
@@ -150,6 +151,7 @@
 /po/remove-potcdate.sed
 /po/remove-potcdate.sin
 /po/stamp-po
+/src/cu-progs.mk
 /src/version.c
 /src/version.h
 /stamp-h1
diff --git a/Makefile.am b/Makefile.am
index b47b1c1..f3d6eda 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -49,6 +49,7 @@ EXTRA_DIST =                          \
   THANKStt.in                          \
   bootstrap                            \
   bootstrap.conf                       \
+  build-aux/gen-lists-of-programs.sh   \
   cfg.mk                               \
   dist-check.mk                                \
   maint.mk                             \
diff --git a/bootstrap.conf b/bootstrap.conf
index 4fc4e67..4ef3fc8 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -327,7 +327,11 @@ xz         -
 bootstrap_post_import_hook ()
 {
   # Automake requires that ChangeLog exist.
-  touch ChangeLog || exit 1
+  touch ChangeLog || return 1
+  # List of coreutils programs.  See heading comments in the invoked
+  # script for more info.
+  build-aux/gen-lists-of-programs.sh --autoconf >m4/cu-progs.m4  || return 1
+  build-aux/gen-lists-of-programs.sh --automake >src/cu-progs.mk || return 1
 }
 
 bootstrap_epilogue()
diff --git a/build-aux/gen-lists-of-programs.sh 
b/build-aux/gen-lists-of-programs.sh
new file mode 100755
index 0000000..ec43ee8
--- /dev/null
+++ b/build-aux/gen-lists-of-programs.sh
@@ -0,0 +1,186 @@
+#!/bin/sh
+# Generate lists of all coreutils programs, to be fed both to Autoconf
+# and Automake, and with further distinctions about how and when these
+# programs should be built.  This is useful to avoid duplicating the
+# definitions of these list among several files ('configure.ac' and
+# 'src/Makefile.am' at least); such duplication had proved a source of
+# inconsistencies and bugs in the past.
+
+set -u
+set -e
+
+# These are the names of programs that are not built nor installed
+# by default.  This list is *not* intended for programs like 'who',
+# 'nice', 'chroot', etc., that are built only when certain requisite
+# system features are detected.
+# Hence, if the user wants to install programs from this list anyway,
+# say A and B, he'll have to use "--enable-install-program=A,B" when
+# invoking configure.
+disabled_by_default_progs='
+    arch
+    hostname
+'
+
+# Programs that can be built only when certain requisite system
+# features are detected.  These prerequisites will be looked for
+# at configure runtime.
+build_if_possible_progs='
+    chroot
+    df
+    hostid
+    libstdbuf.so
+    nice
+    pinky
+    stdbuf
+    stty
+    uptime
+    users
+    who
+'
+
+# All the other programs, to be built by default, and that should
+# be buildable without problems on any target system.
+normal_progs='
+    [
+    base64
+    basename
+    cat
+    chcon
+    chgrp
+    chmod
+    chown
+    cksum
+    comm
+    cp
+    csplit
+    cut
+    date
+    dd
+    dir
+    dircolors
+    dirname
+    du
+    echo
+    env
+    expand
+    expr
+    factor
+    false
+    fmt
+    fold
+    ginstall
+    groups
+    head
+    id
+    join
+    kill
+    link
+    ln
+    logname
+    ls
+    md5sum
+    mkdir
+    mkfifo
+    mknod
+    mktemp
+    mv
+    nl
+    nproc
+    nohup
+    od
+    paste
+    pathchk
+    pr
+    printenv
+    printf
+    ptx
+    pwd
+    readlink
+    realpath
+    rm
+    rmdir
+    runcon
+    seq
+    sha1sum
+    sha224sum
+    sha256sum
+    sha384sum
+    sha512sum
+    shred
+    shuf
+    sleep
+    sort
+    split
+    stat
+    sum
+    sync
+    tac
+    tail
+    tee
+    test
+    timeout
+    touch
+    tr
+    true
+    truncate
+    tsort
+    tty
+    uname
+    unexpand
+    uniq
+    unlink
+    vdir
+    wc
+    whoami
+    yes
+'
+
+me=`echo "$0" | sed 's,.*/,,'`
+msg="Automatically generated by $me.  DO NOT EDIT BY HAND!"
+
+case $#,$1 in
+  1,--autoconf|1,--for-autoconf)
+    echo "dnl $msg"
+    for p in $normal_progs; do
+      test x"$p" = x"[" && p='@<:@'
+      echo "gl_ADD_PROG([optional_bin_progs], [$p])"
+    done
+    # Extra 'echo' to normalize whitespace.
+    echo "no_install_progs_default='`echo $disabled_by_default_progs`'"
+    sed 's/^ *//' <<END
+        # Given the name of a variable containing a space-separated
+        # list of install-by-default programs and the actual list
+        # do-not-install-by-default programs, modify the former variable
+        # to reflect any "do-install" and "don't-install" requests.
+        # That is, add any program specified via --enable-install-program,
+        # and remove any program specified via --enable-no-install-program.
+        # Note how the second argument below is a literal, with ","
+        # separators.  That is required due to the way the macro works,
+        # and since the corresponding ./configure option argument is
+        # comma-separated on input.
+        gl_INCLUDE_EXCLUDE_PROG([optional_bin_progs], [`\
+          echo $disabled_by_default_progs \
+                                    | sed 's/ /,/g'`])
+END
+    ;;
+  1,--automake|1,--for-automake)
+    echo "## $msg"
+    echo no_install__progs =
+    for p in $disabled_by_default_progs; do
+      echo no_install__progs += $p
+    done
+    echo build_if_possible__progs =
+    for p in $build_if_possible_progs; do
+      echo build_if_possible__progs += $p
+    done
+    echo default__progs =
+    for p in $normal_progs; do
+      echo default__progs += $p
+    done
+    ;;
+  *)
+    echo "$0: invalid usage" >&2; exit 2
+    ;;
+esac
+
+exit 0
diff --git a/configure.ac b/configure.ac
index 083fd34..ca038c8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -407,55 +407,13 @@ if test "$elf_sys" = "yes" && \
 fi
 
 ############################################################################
-mk="$srcdir/src/Makefile.am"
-# Extract all literal names from the definition of $(EXTRA_PROGRAMS)
-# in $mk but don't expand the variable references.
-# Append each literal name to $optional_bin_progs.
-v=EXTRA_PROGRAMS
-for gl_i in `sed -n '/^'$v' =/,/[[^\]]$/p' $mk \
-    | sed 's/^  *//;/^\$.*/d;/^'$v' =/d' \
-    | tr -s '\\015\\012\\\\' '   '`; do
-  gl_ADD_PROG([optional_bin_progs], $gl_i)
-done
-
-# As above, extract literal names from the definition of $(no_install__progs)
-# in $mk but don't expand the variable references.
-v=no_install__progs
-t=`sed -n '/^'$v' =/,/[[^\]]$/p' $mk \
-    | sed 's/^  *//;/^\$.*/d;/^'$v' =/d' \
-    | tr -s '\\015\\012\\\\' '   '`
-# Remove any trailing space.
-no_install_progs_default=`echo "$t"|sed 's/ $//'`
-
-# Unfortunately, due to the way autoconf's AS_HELP_STRING works, the list
-# of default-not-installed programs, "arch hostname", must appear in two
-# places: in this file below, and in $mk.  Using "$no_install_progs_default"
-# below cannot work.  And we can't substitute the names into $mk because
-# automake needs the literals, too.
-# The compromise is to ensure that the space-separated list extracted
-# above matches the literal 2nd argument below.
-c="$srcdir/configure.ac"
-re='^g''l_INCLUDE_EXCLUDE_PROG(.* [\[\(.*\)\]])'
-t=`sed -n '/'"$re"'/{s/'"$re"'/\1/;s/,/ /gp
-}' $c`
-case $t in
-  $no_install_progs_default) ;;
-  *) AC_MSG_ERROR([[internal error: g'l_INCLUDE_EXCLUDE_PROG's 2nd arg, $t,
-                   does not match the list of default-not-installed programs
-                   ($no_install_progs_default) also recorded in $mk]],
-                   1) ;;
-esac
 
-# Given the name of a variable containing a space-separated list of
-# install-by-default programs and the actual list do-not-install-by-default
-# programs, modify the former variable to reflect any "do-install" and
-# "don't-install" requests.
-# I.e., add any program name specified via --enable-install-program=..., and
-# remove any program name specified via --enable-no-install-program=...
-# Note how the second argument below is a literal, with "," separators.
-# That is required due to the way the macro works, and since the
-# corresponding ./configure option argument is comma-separated on input.
-gl_INCLUDE_EXCLUDE_PROG([optional_bin_progs], [arch,hostname])
+dnl Autogenerated by the 'gen-lists-of-programs.sh' auxiliary script.
+dnl Issue proper calls to the macros gl_INCLUDE_EXCLUDE_PROG and
+dnl gl_ADD_PROG (updating $optional_bin_progs), and generate the list
+dnl of coreutils programs to be built only upon explicit user request,
+dnl saving that list in the $no_install_progs_default shell variable.
+m4_include([m4/cu-progs.m4])
 
 # Now that we know which programs will actually be built up, figure out
 # which optional helper progs should be compiled.
@@ -478,19 +436,15 @@ MAN=`
 # Normalize whitespace.
 MAN=`echo $MAN`
 
+NO_INSTALL_PROGS_DEFAULT=$no_install_progs_default
+AC_SUBST([NO_INSTALL_PROGS_DEFAULT])
 OPTIONAL_BIN_PROGS=`echo "$optional_bin_progs "|sed 's/ /\$(EXEEXT) /g;s/ $//'`
 AC_SUBST([OPTIONAL_BIN_PROGS])
 OPTIONAL_PKGLIB_PROGS=`echo "$optional_pkglib_progs " | sed 's/ $//'`
 AC_SUBST([OPTIONAL_PKGLIB_PROGS])
-NO_INSTALL_PROGS_DEFAULT=$no_install_progs_default
-AC_SUBST([NO_INSTALL_PROGS_DEFAULT])
 
 AM_CONDITIONAL([CROSS_COMPILING], [test "$cross_compiling" = yes])
 
-# Arrange to rerun configure whenever the file, src/Makefile.am,
-# containing the list of program names changes.
-CONFIG_STATUS_DEPENDENCIES='$(top_srcdir)/src/Makefile.am'
-AC_SUBST([CONFIG_STATUS_DEPENDENCIES])
 ############################################################################
 
 # As long as "grep 'PRI[diouxX]' po/*.pot" reports matches in
diff --git a/src/Makefile.am b/src/Makefile.am
index 9be3acf..3b0ef65 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -15,124 +15,18 @@
 ## You should have received a copy of the GNU General Public License
 ## along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# These are the names of programs that are not installed by default.
-# This list is *not* intended for programs like who, nice, chroot, etc.,
-# that are built only when certain requisite system features are detected.
-# Hence, if you want to install programs from this list anyway, say A and B,
-# use --enable-install-program=A,B
-no_install__progs = \
-  arch hostname
-
-build_if_possible__progs = \
-  chroot       \
-  df           \
-  hostid       \
-  libstdbuf.so \
-  nice         \
-  pinky                \
-  stdbuf       \
-  stty         \
-  uptime       \
-  users                \
-  who
-
 AM_CFLAGS = $(WARN_CFLAGS) $(WERROR_CFLAGS)
 
+# The list of all programs (separated in different variables to express
+# the how and when they should be installed) is defined in this makefile
+# fragment, autogenerated by the 'gen-lists-of-programs.sh' auxiliary
+# script.
+include $(srcdir)/cu-progs.mk
+
 EXTRA_PROGRAMS = \
   $(no_install__progs) \
   $(build_if_possible__progs) \
-  [            \
-  base64       \
-  basename     \
-  cat          \
-  chcon                \
-  chgrp                \
-  chmod                \
-  chown                \
-  cksum                \
-  comm         \
-  cp           \
-  csplit       \
-  cut          \
-  date         \
-  dd           \
-  dir          \
-  dircolors    \
-  dirname      \
-  du           \
-  echo         \
-  env          \
-  expand       \
-  expr         \
-  factor       \
-  false                \
-  fmt          \
-  fold         \
-  ginstall     \
-  groups       \
-  head         \
-  id           \
-  join         \
-  kill         \
-  link         \
-  ln           \
-  logname      \
-  ls           \
-  md5sum       \
-  mkdir                \
-  mkfifo       \
-  mknod                \
-  mktemp       \
-  mv           \
-  nl           \
-  nproc                \
-  nohup                \
-  od           \
-  paste                \
-  pathchk      \
-  pr           \
-  printenv     \
-  printf       \
-  ptx          \
-  pwd          \
-  readlink     \
-  realpath     \
-  rm           \
-  rmdir                \
-  runcon       \
-  seq          \
-  sha1sum      \
-  sha224sum    \
-  sha256sum    \
-  sha384sum    \
-  sha512sum    \
-  shred                \
-  shuf         \
-  sleep                \
-  sort         \
-  split                \
-  stat         \
-  sum          \
-  sync         \
-  tac          \
-  tail         \
-  tee          \
-  test         \
-  timeout      \
-  touch                \
-  tr           \
-  true         \
-  truncate     \
-  tsort                \
-  tty          \
-  uname                \
-  unexpand     \
-  uniq         \
-  unlink       \
-  vdir         \
-  wc           \
-  whoami       \
-  yes
+  $(default__progs)
 
 bin_PROGRAMS = $(OPTIONAL_BIN_PROGS)
 
@@ -620,8 +514,9 @@ check-README:
        $(AM_V_at)diff $(pm) $(pr) && rm -rf $(pr) $(pm)
 
 # Ensure that a by-default-not-installed program (listed in
-# $(no_install__progs) is not also listed in $(EXTRA_PROGRAMS), because
-# if that were to happen, it *would* be installed by default.
+# $(no_install__progs) is not also listed as another $(EXTRA_PROGRAMS)
+# entry, because if that were to happen, it *would* be installed
+# by default.
 .PHONY: check-duplicate-no-install
 check-duplicate-no-install: tr
        $(AM_V_GEN)test -z "`echo '$(EXTRA_PROGRAMS)'| ./tr ' ' '\n' | uniq -d`"
-- 
1.7.12