From 6f5457d33b8e74f1848e57b10fb8370a3cc99a28 Mon Sep 17 00:00:00 2001
From: Chris Bieneman <beanz@apple.com>
Date: Tue, 18 Aug 2015 16:15:44 +0000
Subject: [PATCH] We shouldn't need to pass -fno-strict-aliasing when building
 clang with clang.

Summary: The code comments in the Makefile indicate this was put in place to support issues when building clang with GCC. Today clang's strict aliasing works, so we shouldn't pass -fno-strict-aliasing when building with clang.

Reviewers: bogner, echristo

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D12036

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@245304 91177308-0d34-0410-b5e6-96231b3b80d8
---
 CMakeLists.txt | 5 ++++-
 Makefile       | 5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d808844b14..382770b106 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -253,7 +253,10 @@ configure_file(
 
 # Add appropriate flags for GCC
 if (LLVM_COMPILER_IS_GCC_COMPATIBLE)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-common -Woverloaded-virtual -fno-strict-aliasing")
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-common -Woverloaded-virtual")
+  if (NOT "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-strict-aliasing")
+  endif ()
 
   # Enable -pedantic for Clang even if it's not enabled for LLVM.
   if (NOT LLVM_ENABLE_PEDANTIC)
diff --git a/Makefile b/Makefile
index bbc521f4c0..38b6fd1ada 100644
--- a/Makefile
+++ b/Makefile
@@ -67,8 +67,11 @@ endif
 #   http://gcc.gnu.org/PR41874
 #   http://gcc.gnu.org/PR41838
 #
-# We can revisit this when LLVM/Clang support it.
+# We don't need to do this if the host compiler is clang.
+ifeq ($(CXX_COMPILER), "clang")
 CXX.Flags += -fno-strict-aliasing
+endif
+
 
 # Set up Clang's tblgen.
 ifndef CLANG_TBLGEN
-- 
2.40.0