1
0
mirror of https://github.com/qTox/qTox.git synced 2024-03-22 14:00:36 +08:00
qTox/cmake/CheckAtomic.cmake
jenli669 04a9bc46f4
docs(copyright): update and add copyright info
zealously updates and adds qTox copyright information.

Fixes #5713
2019-06-28 01:18:26 +02:00

110 lines
3.8 KiB
CMake

# Copyright © 2019 by The qTox Project Contributors
#
# This file is part of qTox, a Qt-based graphical interface for Tox.
# qTox is libre software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qTox is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qTox. If not, see <http://www.gnu.org/licenses/>
# atomic builtins are required for threading support.
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)
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -std=c++11")
CHECK_CXX_SOURCE_COMPILES("
#include <atomic>
std::atomic<int> x;
int main() {
return x;
}
" ${varname})
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
endfunction(check_working_cxx_atomics)
function(check_working_cxx_atomics64 varname)
set(OLD_CMAKE_REQUIRED_FLAGS ${CMAKE_REQUIRED_FLAGS})
set(CMAKE_REQUIRED_FLAGS "-std=c++11 ${CMAKE_REQUIRED_FLAGS}")
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})
set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
endfunction(check_working_cxx_atomics64)
# Determine if the compiler has GCC-compatible command-line syntax.
if(NOT DEFINED COMPILER_IS_GCC_COMPATIBLE)
if(CMAKE_COMPILER_IS_GNUCXX)
set(COMPILER_IS_GCC_COMPATIBLE ON)
elseif( MSVC )
set(COMPILER_IS_GCC_COMPATIBLE OFF)
elseif( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
set(COMPILER_IS_GCC_COMPATIBLE ON)
elseif( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel" )
set(COMPILER_IS_GCC_COMPATIBLE ON)
else()
message(STATUS "Warning: Unknown compiler, assume GCC compatible")
set(COMPILER_IS_GCC_COMPATIBLE ON)
endif()
endif()
# This isn't necessary on MSVC, so avoid command-line switch annoyance
# by only running on GCC-like hosts.
if (COMPILER_IS_GCC_COMPATIBLE)
# 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 )
list(APPEND 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()
else()
message(FATAL_ERROR "Host compiler appears to require libatomic, but cannot find it.")
endif()
endif()
endif()
# Check for 64 bit atomic operations.
if(MSVC)
set(HAVE_CXX_ATOMICS64_WITHOUT_LIB True)
else()
check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITHOUT_LIB)
endif()
# 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)
list(APPEND CMAKE_REQUIRED_LIBRARIES "atomic")
check_working_cxx_atomics64(HAVE_CXX_ATOMICS64_WITH_LIB)
if (NOT HAVE_CXX_ATOMICS64_WITH_LIB)
message(FATAL_ERROR "Host compiler must support std::atomic!")
endif()
else()
message(FATAL_ERROR "Host compiler appears to require libatomic, but cannot find it.")
endif()
endif()