diff --git a/CHANGELOG.md b/CHANGELOG.md index 95a12f1c..3dfe22fc 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -69,6 +69,20 @@ https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/593 ## Additions +- LTO support: Allow using LTO/IPO by setting `FSFW_ENABLE_LTO=1`. CMake is able to detect whether + the user compiler supports IPO/LPO. LTO is on by default now. Most modern compilers support it, + can make good use of it and it usually makes the code faster and/or smaller. + After some more research: + Enabling LTO will actually cause the compiler to only produce thin LTO by adding + `-flto -fno-fat-lto-objects` to the compiler options. I am not sure this is an ideal choice + because if an application linking against the FSFW does not use LTO, there can be compile + issues (e.g. observed when compiling the FSFW tests without LTO). This is a known issue as + can be seen in the multiple CMake issues for it: + - https://gitlab.kitware.com/cmake/cmake/-/issues/22913, + - https://gitlab.kitware.com/cmake/cmake/-/issues/16808, + - https://gitlab.kitware.com/cmake/cmake/-/issues/21696 + Easiest solution for now: Keep this option OFF by default. + PR: https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/616 - Linux HAL: Add wiretapping option for I2C. Enabled with `FSFW_HAL_I2C_WIRETAPPING` defined to 1 - Dedicated Version class and constant `fsfw::FSFW_VERSION` containing version information inside `fsfw/version.h` diff --git a/CMakeLists.txt b/CMakeLists.txt index 1df1008b..3cca727e 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -17,11 +17,12 @@ set(FSFW_REVISION 0) # Add the cmake folder so the FindSphinx module is found set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake" ${CMAKE_MODULE_PATH}) +set(FSFW_ETL_LIB_NAME etl) set(FSFW_ETL_LIB_MAJOR_VERSION 20 CACHE STRING - "ETL library major version requirement" + "ETL library major version requirement" ) set(FSFW_ETL_LIB_VERSION ${FSFW_ETL_LIB_MAJOR_VERSION}.27.3 CACHE STRING - "ETL library exact version requirement" + "ETL library exact version requirement" ) set(FSFW_ETL_LINK_TARGET etl::etl) @@ -32,19 +33,28 @@ set(FSFW_CATCH2_LIB_VERSION v${FSFW_CATCH2_LIB_MAJOR_VERSION}.0.0-preview5 CACHE "Catch2 library exact version requirement" ) -set(FSFW_ETL_LIB_NAME etl) +# Keep this off by default for now. See PR: https://egit.irs.uni-stuttgart.de/fsfw/fsfw/pulls/616 +# for information which keeping this on by default is problematic +option(FSFW_ENABLE_IPO "Enable interprocedural optimization or link-time optimization if available" OFF) +if(FSFW_ENABLE_IPO) + include(CheckIPOSupported) + check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_ERROR) + if(NOT IPO_SUPPORTED) + message(STATUS "FSFW | IPO/LTO not supported: ${IPO_ERROR}") + endif() +endif() option(FSFW_GENERATE_SECTIONS - "Generate function and data sections. Required to remove unused code" ON + "Generate function and data sections. Required to remove unused code" ON ) if(FSFW_GENERATE_SECTIONS) - option(FSFW_REMOVE_UNUSED_CODE "Remove unused code" ON) + option(FSFW_REMOVE_UNUSED_CODE "Remove unused code" ON) endif() option(FSFW_BUILD_UNITTESTS "Build unittest binary in addition to static library" OFF) option(FSFW_BUILD_DOCS "Build documentation with Sphinx and Doxygen" OFF) if(FSFW_BUILD_UNITTESTS) - option(FSFW_TESTS_GEN_COV "Generate coverage data for unittests" ON) + option(FSFW_TESTS_GEN_COV "Generate coverage data for unittests" ON) endif() option(FSFW_WARNING_SHADOW_LOCAL_GCC "Enable -Wshadow=local warning in GCC" ON) @@ -71,6 +81,10 @@ set(FSFW_DUMMY_TGT fsfw-dummy) add_library(${LIB_FSFW_NAME}) +if(IPO_SUPPORTED AND FSFW_ENABLE_IPO) + set_property(TARGET ${LIB_FSFW_NAME} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE) +endif() + if(FSFW_BUILD_UNITTESTS) message(STATUS "Building the FSFW unittests in addition to the static library") # Check whether the user has already installed Catch2 first @@ -95,6 +109,9 @@ if(FSFW_BUILD_UNITTESTS) project(${FSFW_TEST_TGT} CXX C) add_executable(${FSFW_TEST_TGT}) + if(IPO_SUPPORTED AND FSFW_ENABLE_IPO) + set_property(TARGET ${FSFW_TEST_TGT} PROPERTY INTERPROCEDURAL_OPTIMIZATION TRUE) + endif() if(FSFW_TESTS_GEN_COV) message(STATUS "Generating coverage data for the library")