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| author | Mike Taves <mwtoews@gmail.com> | 2019-04-21 16:46:29 +1200 |
|---|---|---|
| committer | Mike Taves <mwtoews@gmail.com> | 2019-04-21 21:29:31 +1200 |
| commit | f54f4556234dda885777343ae9b4594aba36c428 (patch) | |
| tree | da88611c6aacc38f25d8c58408845432e1f1656d /src/lib_proj.cmake | |
| parent | cf0a6384741354811f821f1cc63bb7f2b69b9924 (diff) | |
| download | PROJ-f54f4556234dda885777343ae9b4594aba36c428.tar.gz PROJ-f54f4556234dda885777343ae9b4594aba36c428.zip | |
CMake: enable LTO using a flag or property method
Diffstat (limited to 'src/lib_proj.cmake')
| -rw-r--r-- | src/lib_proj.cmake | 51 |
1 files changed, 31 insertions, 20 deletions
diff --git a/src/lib_proj.cmake b/src/lib_proj.cmake index f52f5327..5a0a8070 100644 --- a/src/lib_proj.cmake +++ b/src/lib_proj.cmake @@ -35,23 +35,36 @@ elseif(USE_THREAD AND NOT Threads_FOUND) "required by USE_THREAD option") endif() -option(ENABLE_LTO "Build library with LTO optimization (if available)." OFF) +option(ENABLE_LTO + "Build library with LTO/IPO optimization (if available)." OFF) if(ENABLE_LTO) - # TODO: CMake v3.9 use CheckIPOSupported and set property; see - # https://cmake.org/cmake/help/v3.9/module/CheckIPOSupported.html - if("${CMAKE_C_COMPILER_ID}" STREQUAL "Clang") - include(CheckCXXSourceCompiles) - set(CMAKE_REQUIRED_FLAGS "-Wl,-flto") - check_cxx_source_compiles("int main(){ return 0; }" - COMPILER_SUPPORTS_FLTO_FLAG) - elseif("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel") - # Set INTERPROCEDURAL_OPTIMIZATION property later - set(COMPILER_SUPPORTS_FLTO_FLAG TRUE) - else() - include(CheckCXXCompilerFlag) - check_cxx_compiler_flag("-flto" COMPILER_SUPPORTS_FLTO_FLAG) + # Determine ENABLE_LTO_METHOD to either "flag" or "property" + if(CMAKE_C_COMPILER_ID STREQUAL "Intel" + AND CMAKE_SYSTEM_NAME STREQUAL "Linux") + set(ENABLE_LTO_METHOD "property") + elseif(CMAKE_VERSION VERSION_LESS 3.9) + # Maual checks required + if(CMAKE_C_COMPILER_ID STREQUAL "Clang") + include(CheckCXXSourceCompiles) + set(CMAKE_REQUIRED_FLAGS "-Wl,-flto") + check_cxx_source_compiles("int main(){ return 0; }" + COMPILER_SUPPORTS_FLTO_FLAG) + else() + include(CheckCXXCompilerFlag) + check_cxx_compiler_flag("-flto" COMPILER_SUPPORTS_FLTO_FLAG) + endif() + set(ENABLE_LTO_METHOD "flag") + if(NOT COMPILER_SUPPORTS_FLTO_FLAG) + set(ENABLE_LTO OFF) + endif() + else() # CMake v3.9 + cmake_policy(SET CMP0069 NEW) + include(CheckIPOSupported) + check_ipo_supported(RESULT ENABLE_LTO) + set(ENABLE_LTO_METHOD "property") endif() endif() +boost_report_value(ENABLE_LTO) ############################################## @@ -370,14 +383,12 @@ if("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel") PROPERTIES COMPILE_FLAGS ${FP_PRECISE}) endif() -if(COMPILER_SUPPORTS_FLTO_FLAG) - if("${CMAKE_C_COMPILER_ID}" STREQUAL "Intel") - # Intel supported only, before v3.9 +if(ENABLE_LTO) + if(ENABLE_LTO_METHOD STREQUAL "property") set_property(TARGET ${PROJ_CORE_TARGET} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE) - else() - # Pre CMake v3.9 needs to set flag for other compilers - # see https://gitlab.kitware.com/cmake/cmake/issues/15245 + elseif(ENABLE_LTO_METHOD STREQUAL "flag") + # pre-CMake 3.9 workaround target_compile_options(${PROJ_CORE_TARGET} PRIVATE -flto) endif() endif() |