From 1c334db4c818eb4175e9e246f3fc5d91bcfe1eef Mon Sep 17 00:00:00 2001
From: George Peter Banyard <girgias@php.net>
Date: Wed, 5 Feb 2020 17:36:41 +0100
Subject: [PATCH] Add -Wextra compiler warnings and exclude the trigger happy
 ones

The compile warnings which are explicitly suppressed are:
 * -Wno-implicit-fallthrough
 * -Wno-unused-parameter
 * -Wno-sign-compare
 * -Wno-clobbered, only with GCC

Closes GH-5151
---
 Zend/Zend.m4 | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Zend/Zend.m4 b/Zend/Zend.m4
index fc4634580ec..7c715e853bf 100644
--- a/Zend/Zend.m4
+++ b/Zend/Zend.m4
@@ -221,7 +221,10 @@ else
   AC_DEFINE(ZEND_DEBUG,0,[ ])
 fi
 
-test -n "$GCC" && CFLAGS="$CFLAGS -Wall -Wno-strict-aliasing"
+test -n "$GCC" && CFLAGS="$CFLAGS -Wall -Wextra -Wno-strict-aliasing -Wno-implicit-fallthrough -Wno-unused-parameter -Wno-sign-compare"
+dnl Check if compiler supports -Wno-clobbered (only GCC)
+AX_CHECK_COMPILE_FLAG([-Wno-clobbered], CFLAGS="$CFLAGS -Wno-clobbered", , [-Werror])
+
 test -n "$DEBUG_CFLAGS" && CFLAGS="$CFLAGS $DEBUG_CFLAGS"
 
 if test "$ZEND_ZTS" = "yes"; then