From 2fbb28ece62c8e9a29bdd4e1665a62ece315fd42 Mon Sep 17 00:00:00 2001
From: Eric Leblond <eric@regit.org>
Date: Wed, 31 Oct 2012 15:30:38 +0100
Subject: [PATCH] build: error on implicit function declaration

This patch modifies gcc options to error in case of implicit
declaration. Bug #612 has shown this kind of bugs can be very
costly.
---
 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index a0c7af72e4..c8236539ae 100644
--- a/configure.ac
+++ b/configure.ac
@@ -45,7 +45,7 @@ AC_INIT(configure.ac)
 
     if test "$gccvernum" -ge "400"; then
             dnl gcc 4.0 or later
-            CFLAGS="$CFLAGS -Wextra"
+            CFLAGS="$CFLAGS -Wextra -Werror=implicit-function-declaration"
     else
             CFLAGS="$CFLAGS -W"
     fi