This was introduced in cmake 3.9, but we still support 3.5, so some bits will be removed later
# Basic checks on cmake
cmake_minimum_required(VERSION 3.5)
# Basic checks on cmake
cmake_minimum_required(VERSION 3.5)
+#for lto, to avoid warning (should be removed when switching to requiring cmake >= 3.9)
+cmake_policy(SET CMP0069 NEW)
message(STATUS "Cmake version ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION}")
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_HOME_DIRECTORY}/tools/cmake/Modules)
message(STATUS "Cmake version ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}.${CMAKE_PATCH_VERSION}")
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} ${CMAKE_HOME_DIRECTORY}/tools/cmake/Modules)
-# NOTE, cmake 3.0 has a INTERPROCEDURAL_OPTIMIZATION target
-# property for this (http://www.cmake.org/cmake/help/v3.0/prop_tgt/INTERPROCEDURAL_OPTIMIZATION.html)
if(enable_lto) # User wants LTO. Try if we can do that
set(enable_lto OFF)
if(enable_compile_optimizations
if(enable_lto) # User wants LTO. Try if we can do that
set(enable_lto OFF)
if(enable_compile_optimizations
- AND CMAKE_COMPILER_IS_GNUCC
AND (NOT enable_model-checking))
AND (NOT enable_model-checking))
- # On windows, we need 4.8 or higher to enable lto because of http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50293
- # We are experiencing assertion failures even with 4.8 on MinGW.
- # Push the support forward: will see if 4.9 works when we test it.
- #
- # On Linux, we got the following with GCC 4.8.4 on Centos and Ubuntu
- # lto1: internal compiler error: in output_die, at dwarf2out.c:8478
- # Please submit a full bug report, with preprocessed source if appropriate.
- # So instead, we push the support forward
-
- if ( (CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.8.5")
+ if(CMAKE_VERSION VERSION_LESS "3.9")
+ if ( CMAKE_COMPILER_IS_GNUCC
+ AND (CMAKE_C_COMPILER_VERSION VERSION_GREATER "4.8.5")
AND (LINKER_VERSION VERSION_GREATER "2.22"))
AND (LINKER_VERSION VERSION_GREATER "2.22"))
+ set(enable_lto ON)
+ endif()
+ else()
+ include(CheckIPOSupported)
+ check_ipo_supported(RESULT ipo)
+ if(ipo)
+ set(enable_lto ON)
+ endif()
if(enable_lto)
message(STATUS "LTO seems usable.")
else()
if(enable_lto)
message(STATUS "LTO seems usable.")
else()
message(STATUS "LTO disabled on the command line.")
endif()
if(enable_lto) # User wants LTO, and it seems usable. Go for it
message(STATUS "LTO disabled on the command line.")
endif()
if(enable_lto) # User wants LTO, and it seems usable. Go for it
- set(optCFLAGS "${optCFLAGS} -flto ")
- # See https://gcc.gnu.org/wiki/LinkTimeOptimizationFAQ#ar.2C_nm_and_ranlib:
+ set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
# "Since version 4.9 gcc produces slim object files that only contain
# the intermediate representation. In order to handle archives of
# these objects you have to use the gcc wrappers:
# "Since version 4.9 gcc produces slim object files that only contain
# the intermediate representation. In order to handle archives of
# these objects you have to use the gcc wrappers: