* m4/gnulib-common.m4 (gl_COMMON_BODY): Add _Noreturn.

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

diff --git a/m4/gnulib-common.m4 b/m4/gnulib-common.m4
index 8b73f1d..f3f0a7d 100644 (file)
--- a/m4/gnulib-common.m4
+++ b/m4/gnulib-common.m4
@@ -1,4 +1,4 @@
-# gnulib-common.m4 serial 25
+# gnulib-common.m4 serial 27
 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,
@@ -12,6 +12,17 @@ AC_DEFUN([gl_COMMON], [
   AC_REQUIRE([gl_COMMON_BODY])
 ])
 AC_DEFUN([gl_COMMON_BODY], [
+  AH_VERBATIM([_Noreturn],
+[/* The _Noreturn keyword of draft C1X.  */
+#if ! defined _Noreturn && __STDC_VERSION__ < 201000L
+# if (3 <= __GNUC__ || __GNUC__ == 2 && 8 <= __GNUC_MINOR__ \
+      || 0x5110 <= __SUNPRO_C)
+#  define _Noreturn __attribute__ ((__noreturn__))
+# else
+#  define _Noreturn
+# endif
+#endif
+])
   AH_VERBATIM([isoc99_inline],
 [/* 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
@@ -61,16 +72,49 @@ AC_DEFUN([gl_COMMON_BODY], [
 # expands to a C preprocessor expression that evaluates to 1 or 0, depending
 # whether a gnulib module that has been requested shall be considered present
 # or not.
-AC_DEFUN([gl_MODULE_INDICATOR_CONDITION], [1])
+m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
 
 # gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
 # sets the shell variable that indicates the presence of the given module to
 # a C preprocessor expression that will evaluate to 1.
 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
 [
-  GNULIB_[]m4_translit([[$1]],
-    [abcdefghijklmnopqrstuvwxyz./-],
-    [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])=gl_MODULE_INDICATOR_CONDITION
+  gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
+    [GNULIB_[]m4_translit([[$1]],
+                          [abcdefghijklmnopqrstuvwxyz./-],
+                          [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
+    [gl_MODULE_INDICATOR_CONDITION])
+])
+
+# gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
+# modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
+# The shell variable's value is a C preprocessor expression that evaluates
+# to 0 or 1.
+AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
+[
+  m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
+    [
+     dnl Simplify the expression VALUE || 1 to 1.
+     $1=1
+    ],
+    [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
+                                             [gl_MODULE_INDICATOR_CONDITION])])
+])
+
+# gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
+# modifies the shell variable to include the given condition.  The shell
+# variable's value is a C preprocessor expression that evaluates to 0 or 1.
+AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
+[
+  dnl Simplify the expression 1 || CONDITION to 1.
+  if test "$[]$1" != 1; then
+    dnl Simplify the expression 0 || CONDITION to CONDITION.
+    if test "$[]$1" = 0; then
+      $1=$2
+    else
+      $1="($[]$1 || $2)"
+    fi
+  fi
 ])
 
 # gl_MODULE_INDICATOR([modulename])