build: refactor how lists of coreutils programs are defined

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 asks for them explicitly).  This is
useful to avoid duplicating the definitions of these lists 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 program 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.

1 files changed, 185 insertions, 0 deletions

diff --git a/build-aux/gen-lists-of-programs.sh b/build-aux/gen-lists-of-programs.sh
new file mode 100755
index 000000000..2db0745bc
--- /dev/null
+++ b/build-aux/gen-lists-of-programs.sh
@@ -0,0 +1,185 @@
+#!/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 neither 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.
+# If you would like to install programs from this list anyway, say A and B,
+# 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