Subject: cmake: Check for and use -latomic if needed. Forwarded: https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2458 From: Rylie Pavlik Date: Thu, 24 Apr 2025 11:39:44 -0500 Fixes builds on armel, etc. --- CMakeLists.txt | 1 + cmake/FindCxxAtomics.cmake | 180 ++++++++++++++++++++++++++++++++++ src/xrt/auxiliary/util/CMakeLists.txt | 1 + 3 files changed, 182 insertions(+) create mode 100644 cmake/FindCxxAtomics.cmake diff --git a/CMakeLists.txt b/CMakeLists.txt index 14c2086..d863ab3 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -86,6 +86,7 @@ endif() # Redundant mention of version is required because module defaults to looking for 2.91-compatible, # which the config file for a 3.x says it's not compatible with. find_package(Eigen3 3 REQUIRED) +find_package(CxxAtomics COMPONENTS atomic_uint_fast64_t REQUIRED) find_package(Vulkan MODULE) find_package(HIDAPI MODULE) find_package(bluetooth MODULE) diff --git a/cmake/FindCxxAtomics.cmake b/cmake/FindCxxAtomics.cmake new file mode 100644 index 0000000..ae8e698 --- /dev/null +++ b/cmake/FindCxxAtomics.cmake @@ -0,0 +1,180 @@ +# Copyright 2023-2025, Collabora, Ltd. +# +# SPDX-License-Identifier: BSL-1.0 +# +# Distributed under the Boost Software License, Version 1.0. +# (See accompanying file LICENSE_1_0.txt or copy at +# http://www.boost.org/LICENSE_1_0.txt) +# +# Original Author: +# 2025 Rylie Pavlik + +#[=======================================================================[.rst: +FindCxxAtomics +-------------- + +Find the library to link for atomics in C++, if any. +Components are the atomic typenames. + +Targets +^^^^^^^ + +If successful, import targets are created in the following format: + +``CxxAtomics::TYPENAME`` + +e.g. + +``CxxAtomics::atomic_char`` + +``CxxAtomics::atomic_uint_fast64`` + + +#]=======================================================================] + +include(CheckCXXSourceCompiles) +include(FindPackageHandleStandardArgs) +# find_library(CxxAtomics_LIBRARY NAMES atomic libatomic.so.1) +set(CxxAtomics_LIBRARY atomic) + +# Wraps check_cxx_source_compiles +function(_cxxatomics_check_compiles _typename _cachevar) + set(cxx_atomic_check_code + [[ +#include +static std::${_typename} generator{}; +int main() { + ++generator; + return 0; +} +]]) + check_cxx_source_compiles("${cxx_atomic_check_code}" ${_cachevar}) +endfunction() + +# Set the outvar to true if you need to build with the lib, false if you do not. +function(_cxxatomics_find_needs_lib _typename _outvar) + + _cxxatomics_check_compiles(${_typename} CxxAtomics_${_typename}_NO_LIB) + if(CxxAtomics_${_typename}_NO_LIB) + set(${_outvar} + FALSE + PARENT_SCOPE) + return() + endif() + + set(${_outvar} + TRUE + PARENT_SCOPE) +endfunction() + +function(_cxxatomics_check_typename _typename) + set(CxxAtomics_${_typename}_FOUND FALSE) + + _cxxatomics_find_needs_lib(${_typename} CxxAtomics_${_typename}_NEEDS_LIB) + if(CxxAtomics_${_typename}_NEEDS_LIB) + + if(CxxAtomics_LIBRARY) + set(CMAKE_REQUIRED_LIBRARIES ${CxxAtomics_LIBRARY}) + _cxxatomics_check_compiles(${_typename} + CxxAtomics_${_typename}_WITH_LIB) + if(CxxAtomics_${_typename}_WITH_LIB) + set(CxxAtomics_${_typename}_FOUND TRUE) + endif() + endif() + + if(CxxAtomics_${_typename}_FOUND AND NOT TARGET + CxxAtomics::${_typename}) + add_library(CxxAtomics::${_typename} INTERFACE IMPORTED GLOBAL) + target_link_libraries(CxxAtomics::${_typename} + INTERFACE ${CxxAtomics_LIBRARY}) + endif() + else() + # no lib needed + set(CxxAtomics_${_typename}_FOUND TRUE) + + if(NOT TARGET CxxAtomics::${_typename}) + # no extra requirements + add_library(CxxAtomics::${_typename} INTERFACE IMPORTED GLOBAL) + endif() + endif() + list(APPEND _cxxatomics_required_vars CxxAtomics_${_typename}_FOUND) + set(CxxAtomics_${_typename}_FOUND + "${CxxAtomics_${_typename}_FOUND}" + PARENT_SCOPE) + set(_cxxatomics_required_vars + "${_cxxatomics_required_vars}" + PARENT_SCOPE) +endfunction() + +set(cxxatomics_possible_components + atomic_flag + atomic_ref + atomic_bool + atomic_char + atomic_schar + atomic_uchar + atomic_short + atomic_ushort + atomic_int + atomic_uint + atomic_long + atomic_ulong + atomic_llong + atomic_ullong + atomic_char8_t + atomic_char16_t + atomic_char32_t + atomic_wchar_t + atomic_int8_t + atomic_uint8_t + atomic_int16_t + atomic_uint16_t + atomic_int32_t + atomic_uint32_t + atomic_int64_t + atomic_uint64_t + atomic_int_least8_t + atomic_uint_least8_t + atomic_int_least16_t + atomic_uint_least16_t + atomic_int_least32_t + atomic_uint_least32_t + atomic_int_least64_t + atomic_uint_least64_t + atomic_int_fast8_t + atomic_uint_fast8_t + atomic_int_fast16_t + atomic_uint_fast16_t + atomic_int_fast32_t + atomic_uint_fast32_t + atomic_int_fast64_t + atomic_uint_fast64_t + atomic_intptr_t + atomic_uintptr_t + atomic_size_t + atomic_ptrdiff_t + atomic_intmax_t + atomic_uintmax_t + atomic_signed_lock_free + atomic_unsigned_lock_free) +set(_cxxatomics_required_vars) +if(NOT CxxAtomics_FIND_COMPONENTS) + set(CxxAtomics_FIND_COMPONENTS + atomic_int8_t + atomic_uint8_t + atomic_int16_t + atomic_uint16_t + atomic_int32_t + atomic_uint32_t + atomic_int64_t + atomic_uint64_t) +endif() + +foreach(typename ${CxxAtomics_FIND_COMPONENTS}) + _cxxatomics_check_typename(${typename}) +endforeach() + +find_package_handle_standard_args( + CxxAtomics + REQUIRED_VARS ${_cxxatomics_required_vars} + HANDLE_COMPONENTS) diff --git a/src/xrt/auxiliary/util/CMakeLists.txt b/src/xrt/auxiliary/util/CMakeLists.txt index 567c609..42fa5ab 100644 --- a/src/xrt/auxiliary/util/CMakeLists.txt +++ b/src/xrt/auxiliary/util/CMakeLists.txt @@ -164,6 +164,7 @@ endif() # Internal dependency and doesn't bring in any DSO. target_include_directories(aux_util PRIVATE ${EIGEN3_INCLUDE_DIR}) +target_link_libraries(aux_util PUBLIC CxxAtomics::atomic_uint_fast64_t) #### # Debug UI library