+# GCC flags
+
+test_gcc_flag() {
+ AC_LANG_CONFTEST([int main() {}])
+ $CC -c conftest.c $CFLAGS $@ > /dev/null 2> /dev/null
+ ret=$?
+ rm -f conftest.o
+ return $ret
+}
+
+# If using GCC specify some additional parameters
+if test "x$GCC" = "xyes" ; then
+
+ DESIRED_FLAGS="-Wall -W -Wextra -pedantic -pipe -Wformat -Wold-style-definition -Wdeclaration-after-statement -Wfloat-equal -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wmissing-noreturn -Wshadow -Wendif-labels -Wpointer-arith -Wbad-function-cast -Wcast-qual -Wcast-align -Wwrite-strings -Winline"
+
+ if test "x$HAVE_NETLINK" = "xyes" ; then
+ # Test whether rtnetlink.h can be included when compiled with -std=c99
+ # some distributions (e.g. archlinux) have broken headers that dont
+ # define __u64 with -std=c99
+ AC_MSG_CHECKING([checking whether rtnetlink.h can be included with -std=c99])
+ OLDCFLAGS="$CFLAGS"
+ CFLAGS="-std=c99"
+ AC_TRY_COMPILE([#include <linux/rtnetlink.h>], [],
+ use_stdc99=yes, use_stdc99=no)
+
+ if test x"$use_stdc99" = xyes; then
+ DESIRED_FLAGS="-std=c99 $DESIRED_FLAGS"
+ AC_MSG_RESULT([yes])
+ else
+ AC_MSG_RESULT([no])
+ fi
+
+ CFLAGS="$OLDCFLAGS"
+ else
+ DESIRED_FLAGS="-std=c99 $DESIRED_FLAGS"
+ fi
+
+ for flag in $DESIRED_FLAGS ; do
+ AC_MSG_CHECKING([whether $CC accepts $flag])
+ if test_gcc_flag $flag ; then
+ CFLAGS="$CFLAGS $flag"
+ AC_MSG_RESULT([yes])
+ else
+ AC_MSG_RESULT([no])
+ fi
+ done
+fi
+