qt5base-lts/cmake/FindWrapAtomic.cmake
Moody Liu 4088b27b93 Explicitly check for atomic addition and relaxed load operation support
...and properly find and link against `libatomic` using find_library.
This fixes the qtdeclarative build on the RISC-V platform.

Initial-patch-by: Sprite <SpriteOvO@gmail.com>
Pick-to: 6.2
Pick-to: 6.3
Task-number: QTBUG-99234
Change-Id: I2b5e4812886ce45cb02bed3106ce8c519b294cbe
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
2022-04-18 15:01:53 +00:00

52 lines
1.5 KiB
CMake

# We can't create the same interface imported target multiple times, CMake will complain if we do
# that. This can happen if the find_package call is done in multiple different subdirectories.
if(TARGET WrapAtomic::WrapAtomic)
set(WrapAtomic_FOUND ON)
return()
endif()
include(CheckCXXSourceCompiles)
set (atomic_test_sources "#include <atomic>
#include <cstdint>
int main(int, char **)
{
volatile std::atomic<char> size_1;
volatile std::atomic<short> size_2;
volatile std::atomic<int> size_4;
volatile std::atomic<int64_t> size_8;
++size_1;
++size_2;
++size_4;
++size_8;
(void)size_1.load(std::memory_order_relaxed);
(void)size_2.load(std::memory_order_relaxed);
(void)size_4.load(std::memory_order_relaxed);
(void)size_8.load(std::memory_order_relaxed);
return 0;
}")
check_cxx_source_compiles("${atomic_test_sources}" HAVE_STDATOMIC)
if(NOT HAVE_STDATOMIC)
set(_req_libraries "${CMAKE_REQUIRED_LIBRARIES}")
find_library(atomic_LIB atomic REQUIRED)
set(CMAKE_REQUIRED_LIBRARIES ${atomic_LIB})
check_cxx_source_compiles("${atomic_test_sources}" HAVE_STDATOMIC_WITH_LIB)
set(CMAKE_REQUIRED_LIBRARIES "${_req_libraries}")
endif()
add_library(WrapAtomic::WrapAtomic INTERFACE IMPORTED)
if(HAVE_STDATOMIC_WITH_LIB)
# atomic_LIB is already found above.
target_link_libraries(WrapAtomic::WrapAtomic INTERFACE ${atomic_LIB})
endif()
set(WrapAtomic_FOUND 1)
include(FindPackageHandleStandardArgs)
find_package_handle_standard_args(WrapAtomic DEFAULT_MSG WrapAtomic_FOUND)