configure: Enable system extensions to define _GNU_SOURCE

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/configure.ac b/configure.ac
index f3a9c17d4c336fd66eed3d4fa52f017f4064f277..b8207945528fafe1a08b4a5764beecc0e92790b1 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -65,6 +65,8 @@ AC_PROG_CC_C99
 AC_PROG_CC_C_O
 AC_PROG_GCC_TRADITIONAL
 
+AC_USE_SYSTEM_EXTENSIONS
+
 CC_CHECK_FLAGS_APPEND([with_cflags], [CFLAGS], [\
        -pipe \
        -Wall \