From 490c32c425e7909b8351932857a448ac953131ac Mon Sep 17 00:00:00 2001 From: Nathan Craddock Date: Mon, 27 Apr 2020 14:10:56 +1000 Subject: [PATCH] CMake: add WITH_LINKER_LLD option for unix platforms Can give considerably faster linking, especially for debug builds. This may be enabled by default but needs to be more thoroughly tested. --- CMakeLists.txt | 2 ++ build_files/cmake/platform/platform_unix.cmake | 13 +++++++++++++ 2 files changed, 15 insertions(+) diff --git a/CMakeLists.txt b/CMakeLists.txt index 521dfdf4f02..9f0ff3d1427 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -475,6 +475,8 @@ endif() if(CMAKE_COMPILER_IS_GNUCC) option(WITH_LINKER_GOLD "Use ld.gold linker which is usually faster than ld.bfd" ON) mark_as_advanced(WITH_LINKER_GOLD) + option(WITH_LINKER_LLD "Use ld.lld linker which is usually faster than ld.gold" OFF) + mark_as_advanced(WITH_LINKER_LLD) endif() if(CMAKE_COMPILER_IS_GNUCC OR CMAKE_C_COMPILER_ID MATCHES "Clang") diff --git a/build_files/cmake/platform/platform_unix.cmake b/build_files/cmake/platform/platform_unix.cmake index 050ab8f3ba1..8a89ce40432 100644 --- a/build_files/cmake/platform/platform_unix.cmake +++ b/build_files/cmake/platform/platform_unix.cmake @@ -575,6 +575,19 @@ if(CMAKE_COMPILER_IS_GNUCC) unset(LD_VERSION) endif() + if(WITH_LINKER_LLD) + execute_process( + COMMAND ${CMAKE_C_COMPILER} -fuse-ld=lld -Wl,--version + ERROR_QUIET OUTPUT_VARIABLE LD_VERSION) + if("${LD_VERSION}" MATCHES "LLD") + set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fuse-ld=lld") + set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fuse-ld=lld") + else() + message(STATUS "LLD linker isn't available, using the default system linker.") + endif() + unset(LD_VERSION) + endif() + # CLang is the same as GCC for now. elseif(CMAKE_C_COMPILER_ID MATCHES "Clang") set(PLATFORM_CFLAGS "-pipe -fPIC -funsigned-char -fno-strict-aliasing")