Merge remote-tracking branch 'origin/mueller/add-lto-support' into mueller/refactor-logging-with-fmt

CHANGELOG.md

@@ -46,6 +46,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## 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.
+  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`

CMakeLists.txt

@@ -48,6 +48,13 @@ endif()
 
 option(FSFW_ENABLE_IPO "Enable interprocedural optimization or link-time optimization if available" ON)
 
+include(CheckIPOSupported)
+check_ipo_supported(RESULT IPO_SUPPORTED OUTPUT IPO_ERROR)
+if(NOT IPO_SUPPORTED)
+  message(STATUS "FSFW | IPO/LTO not supported: ${IPO_ERROR}")
+endif()
+
+option(FSFW_ENABLE_IPO "Enable interprocedural optimization or link-time optimization if available" ON)
 option(FSFW_GENERATE_SECTIONS
   "Generate function and data sections. Required to remove unused code" ON
   )
@@ -114,6 +121,9 @@ if(FSFW_BUILD_UNITTESTS)
   project(${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")
     message(STATUS "Targets linking against ${LIB_FSFW_NAME} "