z3/cmake/compiler_lto.cmake

52 lines
2.3 KiB
CMake

option(Z3_LINK_TIME_OPTIMIZATION "Use link time optimiziation" OFF)
if (Z3_LINK_TIME_OPTIMIZATION)
message(STATUS "LTO enabled")
set(build_types_with_lto "RELEASE" "RELWITHDEBINFO")
if (DEFINED CMAKE_CONFIGURATION_TYPES)
# Multi configuration generator
message(STATUS "Note LTO is only enabled for the following configurations: ${build_types_with_lto}")
else()
# Single configuration generator
string(TOUPPER "${CMAKE_BUILD_TYPE}" _build_type_upper)
list(FIND build_types_with_lto "${_build_type_upper}" _index)
if ("${_index}" EQUAL -1)
message(FATAL_ERROR "Configuration ${CMAKE_BUILD_TYPE} does not support LTO."
"You should set Z3_LINK_TIME_OPTIMIZATION to OFF.")
endif()
endif()
set(_lto_compiler_flag "")
set(_lto_linker_flag "")
if (("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") OR
("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU"))
set(_lto_compiler_flag "-flto")
set(_lto_linker_flag "-flto")
elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
set(_lto_compiler_flag "/GL")
set(_lto_linker_flag "/LTCG")
else()
message(FATAL_ERROR "Can't enable LTO for compiler \"${CMAKE_CXX_COMPILER_ID}\"."
"You should set Z3_LINK_TIME_OPTIMIZATION to OFF.")
endif()
CHECK_CXX_COMPILER_FLAG("${_lto_compiler_flag}" HAS_LTO)
if (NOT HAS_LTO)
message(FATAL_ERROR "Compiler does not support LTO")
endif()
foreach (_config ${build_types_with_lto})
# Set flags compiler and linker flags globally rather than using
# `Z3_COMPONENT_CXX_FLAGS` and `Z3_DEPENDENT_EXTRA_CXX_LINK_FLAGS`
# respectively. We need per configuration compiler and linker flags. The
# `LINK_FLAGS` property (which we populate with
# `Z3_DEPENDENT_EXTRA_CXX_LINK_FLAGS`) doesn't seem to support generator
# expressions so we can't do `$<$<CONFIG:Release>:${_lto_linker_flag}>`.
set(CMAKE_CXX_FLAGS_${_config} "${CMAKE_CXX_FLAGS_${_config}} ${_lto_compiler_flag}")
set(CMAKE_EXE_LINKER_FLAGS_${_config} "${CMAKE_EXE_LINKER_FLAGS_${_config}} ${_lto_linker_flag}")
set(CMAKE_SHARED_LINKER_FLAGS_${_config} "${CMAKE_SHARED_LINKER_FLAGS_${_config}} ${_lto_linker_flag}")
set(CMAKE_STATIC_LINKER_FLAGS_${_config} "${CMAKE_STATIC_LINKER_FLAGS_${_config}} ${_lto_linker_flag}")
endforeach()
else()
message(STATUS "LTO disabled")
endif()