configure: request/set the compiler in C99 mode
Required by intel and drmstat at least. Considering that every compiler
used to build libdrm is C99 compatible, just enable it for the whole
build.
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
diff --git a/configure.ac b/configure.ac
index e715262..320e482 100644
--- a/configure.ac
+++ b/configure.ac
@@ -36,6 +36,11 @@
# Check for programs
AC_PROG_CC
+AC_PROG_CC_C99
+
+if test "x$ac_cv_prog_cc_c99" = xno; then
+ AC_MSG_ERROR([Building libdrm requires C99 enabled compiler])
+fi
AC_USE_SYSTEM_EXTENSIONS
AC_SYS_LARGEFILE