1 files changed, 48 insertions, 0 deletions
diff --git a/m4/ac_valist.m4 b/m4/ac_valist.m4
new file mode 100644
index 000000000..a4d6a2493
--- /dev/null
+++ b/m4/ac_valist.m4
@@ -0,0 +1,48 @@
+dnl That code is public domain and can be freely used or copied.
+dnl Originally snatched from somewhere...
+
+dnl Macro for checking if va_list is an array
+
+dnl Usage: AC_C_VA_LIST_AS_ARRAY
+dnl call AC_DEFINE for HAVE_VA_LIST_AS_ARRAY
+dnl if for this architecture va_list is defined as an array
+
+AC_DEFUN([AC_C_VA_LIST_AS_ARRAY],
+[
+
+AC_MSG_CHECKING([whether va_list is defined as an array])
+
+AC_CACHE_VAL([ac_cv_valistasarray],
+   [AC_TRY_RUN(
+       [
+#include <stdlib.h>
+#include <stdarg.h>
+void foo(int i, ...)
+{
+	va_list ap1, ap2;
+	va_start(ap1, i);
+	ap2 = ap1;
+	if (va_arg(ap2, int) != 123 || va_arg(ap1, int) != 123)
+		exit(1);
+	va_end(ap1);
+}
+int main(void)
+{
+	foo(0, 123);
+	return(0);
+}
+       ],
+       [ac_cv_valistasarray="no"],
+       [ac_cv_valistasarray="yes"],
+       [ac_cv_valistasarray="no"]
+    )])
+
+AC_MSG_RESULT($ac_cv_valistasarray)
+
+if test "x${ac_cv_valistasarray}" = "xyes" ; then
+   AC_DEFINE([HAVE_VA_LIST_AS_ARRAY], [1], [Define to 1 if va_list is an array])
+fi
+
+])
+
+dnl End of ac_valist.m4