From 7db79d9c13f1d643703e267f9886102bdbf6c9cf Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Mon, 3 Feb 2014 13:57:09 +0000 Subject: Don't use -ffunction-sections if -fno-function-sections is not supported in the compiler. This will disable -ffunction-sections in older versions of Clang where it breaks build of sanitizer runtime library. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200695 91177308-0d34-0410-b5e6-96231b3b80d8 --- cmake/modules/HandleLLVMOptions.cmake | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/cmake/modules/HandleLLVMOptions.cmake b/cmake/modules/HandleLLVMOptions.cmake index 47d3b2f79d..38bbd2ea7e 100644 --- a/cmake/modules/HandleLLVMOptions.cmake +++ b/cmake/modules/HandleLLVMOptions.cmake @@ -350,13 +350,23 @@ if (UNIX AND append("-fcolor-diagnostics" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) endif() +# Clang prior to 3.5 ignored -fno-function-sections. +# It's pretty hard to test directly, so we rely on the version number. +if( ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") AND (CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.5) ) + set(LLVM_COMPILER_HAS_BROKEN_FNO_FUNCTION_SECTIONS ON) +endif() + # Add flags for add_dead_strip(). # FIXME: With MSVS, consider compiling with /Gy and linking with /OPT:REF? # But MinSizeRel seems to add that automatically, so maybe disable these # flags instead if LLVM_NO_DEAD_STRIP is set. if(NOT CYGWIN AND NOT WIN32) if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin") - append("-ffunction-sections -fdata-sections" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) + # Don't add -ffunction-section if it can be disabled with -fno-function-sections. + # Doing so will break sanitizers. + if (NOT LLVM_COMPILER_HAS_BROKEN_FNO_FUNCTION_SECTIONS) + append("-ffunction-sections -fdata-sections" CMAKE_C_FLAGS CMAKE_CXX_FLAGS) + endif() endif() endif() -- cgit v1.2.3