+2011-09-30 Bruno Haible <bruno@clisp.org>
+
+ Centralize C99 requirement.
+ * m4/gnulib-common.m4 (gl_PROG_CC_C99): New macro.
+ * modules/stdarg (configure.ac-early): Invoke it instead of
+ AC_PROG_CC_STDC.
+ Reported by Gary V. Vaughan and Paul Eggert.
+
2011-09-29 Bruno Haible <bruno@clisp.org>
float: Fix LDBL_MAX value on Linux/PowerPC.
-# gnulib-common.m4 serial 30
+# gnulib-common.m4 serial 31
dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
[m4_define([AS_VAR_IF],
[AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
+# gl_PROG_CC_C99
+# Modifies the value of the shell variable CC in an attempt to make $CC
+# understand ISO C99 source code.
+# This is like AC_PROG_CC_C99, except that
+# - AC_PROG_CC_C99 did not exist in Autoconf versions < 2.60,
+# - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
+# <http://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00367.html>,
+# but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
+# <http://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00441.html>.
+# Remaining problems:
+# - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options
+# to CC twice
+# <http://lists.gnu.org/archive/html/bug-gnulib/2011-09/msg00431.html>.
+# - AC_PROG_CC_STDC is likely to change when C1X is an ISO standard.
+AC_DEFUN([gl_PROG_CC_C99],
+[
+ dnl Change that version number to the minimum Autoconf version that supports
+ dnl mixing AC_PROG_CC_C99 calls with AC_PROG_CC_STDC calls.
+ m4_version_prereq([9.0],
+ [AC_REQUIRE([AC_PROG_CC_C99])],
+ [AC_REQUIRE([AC_PROG_CC_STDC])])
+])
+
# gl_PROG_AR_RANLIB
# Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
# The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
configure.ac-early:
dnl Some compilers (e.g., AIX 5.3 cc) need to be in c99 mode
dnl for the builtin va_copy to work. With Autoconf 2.60 or later,
-dnl AC_PROG_CC_STDC arranges for this. With older Autoconf AC_PROG_CC_STDC
+dnl gl_PROG_CC_C99 arranges for this. With older Autoconf gl_PROG_CC_C99
dnl shouldn't hurt, though installers are on their own to set c99 mode.
-AC_REQUIRE([AC_PROG_CC_STDC])
+gl_PROG_CC_C99
configure.ac:
gl_STDARG_H