Change language specification to c11 in the autoconf builds

Fixes an issue with certain glibc versions using the emulated
`_Static_assert` (allowing only one assertion per scope) despite the
compiler having built-in support for the c11 version.

Fixes builds in Debian stretch and other distributions.

Signed-off-by: Haru <haru@dotalux.com>

1 files changed, 45 insertions, 2 deletions

diff --git a/configure b/configure
index 3a33cebd3..180fe971d 100755
--- a/configure
+++ b/configure
@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.ac 515eed8ee.
+# From configure.ac 234189f34.
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.69.
 #
@@ -4776,7 +4776,50 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 #   -Werror-implicit-function-declaration -Wtrampolines
 #   -Wjump-misses-init
 
-CFLAGS="$CFLAGS -pipe -ffast-math -Wall -Wextra -Wno-sign-compare -std=c99"
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC supports -std=c11" >&5
+$as_echo_n "checking whether $CC supports -std=c11... " >&6; }
+OLD_CFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -std=c11"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+int foo;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+else
+
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+		{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CC supports -std=c1x" >&5
+$as_echo_n "checking whether $CC supports -std=c1x... " >&6; }
+		CFLAGS="$OLD_CFLAGS -std=c1x"
+		cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+int foo;
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+				{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+else
+
+				{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no, falling back to -std=c99" >&5
+$as_echo "no, falling back to -std=c99" >&6; }
+				CFLAGS="$OLD_CFLAGS -std=c99"
+
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+CFLAGS="$CFLAGS -pipe -ffast-math -Wall -Wextra -Wno-sign-compare"
 CPPFLAGS="$CPPFLAGS -I../common"
 LDFLAGS="$LDFLAGS"