From 2cb42c9d446459635733924462430946fb17bbca Mon Sep 17 00:00:00 2001
From: Hans-Christian Ebke <ebke@cs.rwth-aachen.de>
Date: Wed, 14 Sep 2016 12:11:21 +0200
Subject: [PATCH] Added a little safeguard against GCC optimizer bug to
 CMakeLists.txt.

---
 CMakeLists.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index c05a6284..ac86b67e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -7,6 +7,14 @@ if("${PROJECT_NAME}" STREQUAL "")
     project (OpenMesh)
 endif()
 
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+	if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS "6.0" AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER "4.9" OR CMAKE_CXX_COMPILER_VERSION VERSION_EQUAL "4.9")
+		message(WARNING "Your version of GCC contains an optimizer bug. Please verify that you do not use -O3!")
+		string(REPLACE "-O3" "-O2" CMAKE_CXX_FLAGS_RELEASE_NEW "${CMAKE_CXX_FLAGS_RELEASE}")
+		set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE_NEW}" CACHE STRING "" FORCE)
+	endif()
+endif()
+
 if ( WIN32 )
   # This is the base directory for windows library search used in the finders we ship.
   set(CMAKE_WINDOWS_LIBS_DIR "c:/libs" CACHE STRING "Default Library search dir on windows." )