diff options
Diffstat (limited to 'host/cmake')
| -rw-r--r-- | host/cmake/Modules/UHDAtomics.cmake | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/host/cmake/Modules/UHDAtomics.cmake b/host/cmake/Modules/UHDAtomics.cmake new file mode 100644 index 000000000..4d53a2d0b --- /dev/null +++ b/host/cmake/Modules/UHDAtomics.cmake @@ -0,0 +1,80 @@ +# +# This file is mostly inspired by +# https://github.com/llvm-mirror/llvm/blob/master/cmake/modules/CheckAtomic.cmake +# +# SPDX-License-Identifier: GPL-3.0-or-later +# + +include(CheckCXXSourceCompiles) +include(CheckLibraryExists) + +# Sometimes linking against libatomic is required for atomic ops, if +# the platform doesn't support lock-free atomics. + +function(CHECK_WORKING_CXX_ATOMICS varname) + CHECK_CXX_SOURCE_COMPILES(" + #include <atomic> + std::atomic<int> x; + int main() { + return x; + } + " ${varname}) +endfunction(CHECK_WORKING_CXX_ATOMICS) + +function(CHECK_WORKING_CXX_ATOMICS64 varname) + CHECK_CXX_SOURCE_COMPILES(" + #include <atomic> + #include <cstdint> + std::atomic<uint64_t> x (0); + int main() { + uint64_t i = x.load(std::memory_order_relaxed); + return 0; + } + " ${varname}) +endfunction(CHECK_WORKING_CXX_ATOMICS64) + +macro(CHECK_ATOMICS_LIB_REQUIRED required_var) + set(${required_var} FALSE) + if(MSVC) + set(${required_var} FALSE) + else() + # First check if atomics work without the library. + CHECK_WORKING_CXX_ATOMICS(HAVE_CXX_ATOMICS_WITHOUT_LIB) + # If not, check if the library exists, and atomics work with it. + if(NOT HAVE_CXX_ATOMICS_WITHOUT_LIB) + check_library_exists(atomic __atomic_fetch_add_4 "" HAVE_LIBATOMIC) + if(HAVE_LIBATOMIC) + set(${required_var} TRUE) + set(CMAKE_REQUIRED_LIBRARIES "atomic") + CHECK_WORKING_CXX_ATOMICS(HAVE_CXX_ATOMICS_WITH_LIB) + if (NOT HAVE_CXX_ATOMICS_WITH_LIB) + message(FATAL_ERROR "Host compiler must support std::atomic!") + endif() + unset(CMAKE_REQUIRED_LIBRARIES) + else() + message( + FATAL_ERROR + "Host compiler appears to require libatomic, but cannot find it.") + endif() + endif() + # Same check, but for 64-bit atomics. + CHECK_WORKING_CXX_ATOMICS64(HAVE_CXX_ATOMICS64_WITHOUT_LIB) + # If not, check if the library exists, and atomics work with it. + if(NOT HAVE_CXX_ATOMICS64_WITHOUT_LIB) + check_library_exists(atomic __atomic_load_8 "" HAVE_CXX_LIBATOMICS64) + if(HAVE_CXX_LIBATOMICS64) + set(${required_var} TRUE) + set(CMAKE_REQUIRED_LIBRARIES "atomic") + CHECK_WORKING_CXX_ATOMICS64(HAVE_CXX_ATOMICS64_WITH_LIB) + unset(CMAKE_REQUIRED_LIBRARIES) + if (NOT HAVE_CXX_ATOMICS64_WITH_LIB) + message(FATAL_ERROR "Host compiler must support 64-bit std::atomic!") + endif() + else() + message( + FATAL_ERROR + "Host compiler appears to require libatomic for 64-bit operations, but cannot find it.") + endif() + endif() + endif() +endmacro(CHECK_ATOMICS_LIB_REQUIRED) |