From 4d1c117f5bc0200b7484b95ad07c856c6b9003cd Mon Sep 17 00:00:00 2001
From: Johann <johannkoenig@google.com>
Date: Wed, 31 Aug 2016 22:17:38 -0700
Subject: [PATCH] Enable -Wundef by default

BUG=webm:1069

Change-Id: I43728f9fd007542718a55d5fdcbc63a8d2f86682
---
 configure | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/configure b/configure
index e88e5698c..638e19750 100755
--- a/configure
+++ b/configure
@@ -574,6 +574,9 @@ process_toolchain() {
         check_add_cflags -Wimplicit-function-declaration
         check_add_cflags -Wuninitialized
         check_add_cflags -Wunused
+        # check_add_cflags also adds to cxxflags. gtest does not do well with
+        # -Wundef so add it explicitly to CFLAGS only.
+        check_cflags -Wundef && add_cflags_only -Wundef
         case ${CC} in
           *clang*)
               # libvpx and/or clang have issues with aliasing: