From: Lucas De Marchi <lucas.demarchi@intel.com>
Date: Thu, 26 Feb 2015 16:02:04 +0000 (-0300)
Subject: shared: avoid checking for __STDC_VERSION__
X-Git-Tag: v20~10
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=16a62c7ab3846a1996624cccc0e16dd4adb5deb0;p=thirdparty%2Fkmod.git

shared: avoid checking for __STDC_VERSION__

Since we pass -std=gnu99 to the compiler __STDC_VERSION__ is defined to
199901. Even in this case we can use _Noreturn. Delegate the testing to
the configure phase with a compile test.

In future we want to stop using AC_PROG_CC_99 and start using the new
AC_PROG_CC from autoconf 2.70, which tries to choose the most recent
standard.
---

diff --git a/configure.ac b/configure.ac
index 3ba65cca..ecf3e838 100644
--- a/configure.ac
+++ b/configure.ac
@@ -65,6 +65,14 @@ AC_COMPILE_IFELSE(
 	 AC_MSG_RESULT([yes])],
 	[AC_MSG_RESULT([no])])
 
+AC_MSG_CHECKING([whether _Noreturn is supported])
+AC_COMPILE_IFELSE(
+	[AC_LANG_SOURCE([[_Noreturn int foo(void) { exit(0); }]])],
+        [AC_DEFINE([HAVE_NORETURN], [1], [Define if _Noreturn is available])
+	 AC_MSG_RESULT([yes])],
+	[AC_MSG_RESULT([no])])
+
+
 #####################################################################
 # --with-
 #####################################################################
diff --git a/shared/macro.h b/shared/macro.h
index a081a495..4fc54059 100644
--- a/shared/macro.h
+++ b/shared/macro.h
@@ -63,7 +63,7 @@
 /* Define C11 noreturn without <stdnoreturn.h> and even on older gcc
  * compiler versions */
 #ifndef noreturn
-#if __STDC_VERSION__ >= 201112L
+#if defined(HAVE_NORETURN)
 #define noreturn _Noreturn
 #else
 #define noreturn __attribute__((noreturn))