use m4 -g when available

M4sugar requires GNU m4 extensions to be enabled.  Override
POSIXLY_CORRECT using -g.

* m4/m4.m4: Unset POSIXLY_CORRECT during first test.  Test for -g.
Warn user if he has POSIXLY_CORRECT set but -g is not supported.
* bin/Makefile.am: Substitute @M4_GNU@ into generated files.
* bin/autom4te.in: Pass @M4_GNU@ to m4.

diff --git a/ChangeLog b/ChangeLog
index f5434bda7116df35036cb8f169d6c1b6a892c7c0..67520c05c6411a7da2d936eb05d1383a1bd87bcf 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-07-13  Paolo Bonzini  <bonzini@gnu.org>
+
+       Use m4 -g when available.
+       * m4/m4.m4: Unset POSIXLY_CORRECT during first test.  Test for -g.
+       Warn user if he has POSIXLY_CORRECT set but -g is not supported.
+       * bin/Makefile.am: Substitute @M4_GNU@ into generated files.
+       * bin/autom4te.in: Pass @M4_GNU@ to m4.
+
 2009-07-13  Eric Blake  <ebb9@byu.net>
 
        Fix previous patch.

diff --git a/bin/Makefile.am b/bin/Makefile.am
index ba88ab01f5899b1bd1349fad0523131b9cb6c7ef..da65b85ff4a0fb419cd50fbae2164e773d65746f 100644 (file)
--- a/bin/Makefile.am
+++ b/bin/Makefile.am
@@ -46,6 +46,7 @@ edit = sed \
        -e 's|@autom4te-name[@]|'`echo autom4te | sed '$(transform)'`'|g' \
        -e 's|@M4[@]|$(M4)|g' \
        -e 's|@M4_DEBUGFILE[@]|$(M4_DEBUGFILE)|g' \
+       -e 's|@M4_GNU[@]|$(M4_GNU)|g' \
        -e 's|@AWK[@]|$(AWK)|g' \
        -e 's|@RELEASE_YEAR[@]|'$(RELEASE_YEAR)'|g' \
        -e 's|@VERSION[@]|$(VERSION)|g' \

diff --git a/bin/autom4te.in b/bin/autom4te.in
index cf425bb43f5a50e2daaf4a44f54cecbe89a3a778..1baf507ffcd51e289a9c506414c75b888fa821d0 100644 (file)
--- a/bin/autom4te.in
+++ b/bin/autom4te.in
@@ -463,7 +463,7 @@ sub handle_m4 ($@)
   #
   # We don't output directly to the cache files, to avoid problems
   # when we are interrupted (that leaves corrupted files).
-  xsystem ("$m4"
+  xsystem ("$m4 @M4_GNU@"
           . join (' --include=', '', map { shell_quote ($_) } @include)
           . ' --debug=aflq'
           . (!exists $ENV{'AUTOM4TE_NO_FATAL'} ? ' --fatal-warning' : '')

diff --git a/m4/m4.m4 b/m4/m4.m4
index dd90cca5e0871142921f21acdd115c0ac7dc2ce9..975f24a84206188c0bc1b3ecd9b43e1dcdf46c30 100644 (file)
--- a/m4/m4.m4
+++ b/m4/m4.m4
@@ -1,4 +1,4 @@
-# m4.m4 serial 6
+# m4.m4 serial 7
 
 # Copyright (C) 2000, 2006, 2007, 2008, 2009 Free Software Foundation,
 # Inc.
@@ -20,6 +20,8 @@ AC_DEFUN([AC_PROG_GNU_M4],
     program of `m4', `gm4', or `gnum4' on PATH that meets Autoconf needs.])
   AC_CACHE_CHECK([for GNU M4 that supports accurate traces], [ac_cv_path_M4],
     [rm -f conftest.m4f
+ac_had_posixly_correct=${POSIXLY_CORRECT:+yes}
+AS_UNSET([POSIXLY_CORRECT])
 AC_PATH_PROGS_FEATURE_CHECK([M4], [m4 gm4 gnum4],
       [dnl Creative quoting here to avoid raw dnl and ifdef in configure.
       # Root out GNU M4 1.4.4, as well as non-GNU m4 that ignore -t, -F.
@@ -32,6 +34,24 @@ AC_PATH_PROGS_FEATURE_CHECK([M4], [m4 gm4 gnum4],
       [AC_MSG_ERROR([no acceptable m4 could be found in \$PATH.
 GNU M4 1.4.5 or later is required; 1.4.11 is recommended])])])
   M4=$ac_cv_path_M4
+  AC_CACHE_CHECK([whether $ac_cv_path_M4 accepts -g], [ac_cv_prog_gnu_m4_gnu],
+    [case `$M4 --help < /dev/null 2>&1` in
+      *--gnu*) ac_cv_prog_gnu_m4_gnu=yes ;;
+      *) ac_cv_prog_gnu_m4_gnu=no ;;
+    esac])
+  if test "$ac_cv_prog_gnu_m4_gnu" = yes; then
+    M4_GNU=-g
+  else
+    M4_GNU=
+  fi
+  AC_SUBST([M4_GNU])
+  if test x$ac_had_posixly_correct = xyes; then
+    POSIXLY_CORRECT=:
+    if test $ac_cv_prog_gnu_m4_gnu = no; then
+      AC_MSG_WARN([The version of M4 that was found does not support -g.])
+      AC_MSG_WARN([Using it with POSIXLY_CORRECT set may cause problems.])
+    fi
+  fi
   AC_CACHE_CHECK([how m4 supports trace files], [ac_cv_prog_gnu_m4_debugfile],
     [case `$M4 --help < /dev/null 2>&1` in
       *debugfile*) ac_cv_prog_gnu_m4_debugfile=--debugfile ;;