Compile with -std=c11 along with _POSIX_C_SOURCE=200112L.

With gcc 5.1 released and defaulting to std=gnu11, the code will be compiled
according to different standards depending on the compiler version so we
should better specify explicitly what standard we are targetting.
C11 is now quite mature, it is supported in the just release Debian stable
(gcc 4.9) and also in old-stable (gcc 4.7), so there should be no reason to
use anything more ancient.
We also should have no reason to need any non-standard GNU extension.
So using only C11 + POSIX sounds like the best option right now.

diff --git a/configure.ac b/configure.ac
index bc9ce7128aaab2c50e4a3cd3fa98b39cb964ea4a..85087b5d6c8f5b75c2a06e16748fd7d0580dd491 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -45,7 +45,7 @@ AH_BOTTOM([#endif /* SR_CONFIG_H */])
 # Enable more compiler warnings via -Wall and -Wextra. Add -fvisibility=hidden
 # and enforce use of SR_API to explicitly mark all public API functions.
 COMMON_FLAGS="$CFLAGS -Wall -Wextra -fvisibility=hidden"
-CFLAGS="$COMMON_FLAGS -Wmissing-prototypes"
+CFLAGS="$COMMON_FLAGS -std=c11 -D_POSIX_C_SOURCE=200112L -Wmissing-prototypes"
 CXXFLAGS="-std=c++11 $COMMON_FLAGS"
 
 # Checks for programs.