ChangeLog (2006-09-15): add Odd Arild Olsen's role for push.c.

[bison.git] / m4 / m4.m4

diff --git a/m4/m4.m4 b/m4/m4.m4
index f27d8c052013489d7d842c3f12a294569b11d868..a67b902b776771c6627ab88aa7a818432af7bdc6 100644 (file)
--- a/m4/m4.m4
+++ b/m4/m4.m4
@@ -1,33 +1,59 @@
-# m4.m4 serial 5
-dnl Copyright (C) 2000, 2006, 2007, 2008 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.
+# m4.m4 serial 10
+
+# Copyright (C) 2000, 2006-2010 Free Software Foundation, Inc.
+
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.  This file is offered as-is,
+# without warranty of any kind.
 
 # AC_PROG_GNU_M4
 # --------------
-# Check for GNU M4, at least 1.4.5 (all earlier versions had a bug in
-# trace support:
-# http://lists.gnu.org/archive/html/bug-gnu-utils/2006-11/msg00096.html)
+# Check for GNU M4, at least 1.4.6 (all earlier versions had bugs in
+# trace support and regexp support):
+# http://lists.gnu.org/archive/html/bug-gnu-utils/2006-11/msg00096.html
+# http://lists.gnu.org/archive/html/bug-autoconf/2009-07/msg00023.html
 # Also, check whether --error-output (through 1.4.x) or --debugfile (2.0)
 # is supported, and AC_SUBST M4_DEBUGFILE accordingly.
 AC_DEFUN([AC_PROG_GNU_M4],
-  [AC_ARG_VAR([M4], [Location of GNU M4 1.4.5 or later.  Defaults to the first
+  [AC_ARG_VAR([M4], [Location of GNU M4 1.4.6 or later.  Defaults to the first
     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=${POSIXLY_CORRECT:+yes}
+AS_UNSET([POSIXLY_CORRECT])
 AC_PATH_PROGS_FEATURE_CHECK([M4], [m4 gm4 gnum4],
       [dnl Creative quoting here to avoid raw dnl and ifdef in configure.
-      # Root out GNU M4 1.4.4, as well as non-GNU m4 that ignore -t, -F.
-      ac_snippet=change'quote(<,>)in''dir(<if''def>,mac,bug)d'nl
+      # Root out GNU M4 1.4.5, as well as non-GNU m4 that ignore -t, -F.
+      ac_snippet=change'quote(<,>)in''dir(<if''def>,mac,bug)'
+      ac_snippet=${ac_snippet}pat'subst(a,\(b\)\|\(a\),\1)d'nl
       test -z "`$ac_path_M4 -F conftest.m4f </dev/null 2>&1`" \
-      && test -z "`echo $ac_snippet | $ac_path_M4 --trace=mac 2>&1`" \
+      && test -z "`AS_ECHO([$ac_snippet]) | $ac_path_M4 --trace=mac 2>&1`" \
       && test -f conftest.m4f \
       && ac_cv_path_M4=$ac_path_M4 ac_path_M4_found=:
       rm -f conftest.m4f],
       [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])])])
+GNU M4 1.4.6 or later is required; 1.4.13 is recommended])])])
   M4=$ac_cv_path_M4
+  AC_CACHE_CHECK([whether $ac_cv_path_M4 accepts --gnu],
+    [ac_cv_prog_gnu_m4_gnu],
+    [case `$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 "$ac_cv_prog_gnu_m4_gnu" = yes; then
+    M4_GNU=--gnu
+  else
+    M4_GNU=
+  fi
+  AC_SUBST([M4_GNU])
+  if test x$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 ;;