merge trunk

[bpt/emacs.git] / m4 / gnulib-common.m4

diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 8fc448f..15d2b2b 100644 (file)
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,5 +1,5 @@
-# gnulib-common.m4 serial 30
-dnl Copyright (C) 2007-2011 Free Software Foundation, Inc.
+# gnulib-common.m4 serial 33
+dnl Copyright (C) 2007-2012 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.
@@ -13,12 +13,13 @@ AC_DEFUN([gl_COMMON], [
 ])
 AC_DEFUN([gl_COMMON_BODY], [
   AH_VERBATIM([_Noreturn],
-[/* The _Noreturn keyword of draft C1X.  */
-#ifndef _Noreturn
+[/* The _Noreturn keyword of C11.  */
+#if ! (defined _Noreturn \
+       || (defined __STDC_VERSION__ && 201112 <= __STDC_VERSION__))
 # if (3 <= __GNUC__ || (__GNUC__ == 2 && 8 <= __GNUC_MINOR__) \
       || 0x5110 <= __SUNPRO_C)
 #  define _Noreturn __attribute__ ((__noreturn__))
-# elif 1200 <= _MSC_VER
+# elif defined _MSC_VER && 1200 <= _MSC_VER
 #  define _Noreturn __declspec (noreturn)
 # else
 #  define _Noreturn
@@ -29,7 +30,7 @@ AC_DEFUN([gl_COMMON_BODY], [
 [/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
    the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
    earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
-   __APPLE__ && __MACH__ test for MacOS X.
+   __APPLE__ && __MACH__ test for Mac OS X.
    __APPLE_CC__ tests for the Apple compiler and its version.
    __STDC_VERSION__ tests for the C99 mode.  */
 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
@@ -211,6 +212,29 @@ m4_ifndef([AS_VAR_IF],
 [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 now that C11 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