Move CheckAtomic cmake module out of the shared cmake dir

Summary: Remove the shared CheckAtomic cmake module out of the shared dir and back to the projects that need it.

Reviewed By: lukaspiatkowski

Differential Revision: D19553656

fbshipit-source-id: 5e89b5b9448ef6d6c57ef904a652e9f9a1d5dbb3

build/fbcode_builder/CMake/CheckAtomic.cmake

-# University of Illinois/NCSA
-# Open Source License
-#
-# Copyright (c) 2003-2017 University of Illinois at Urbana-Champaign.
-# All rights reserved.
-#
-# Developed by:
-#
-#     LLVM Team
-#
-#     University of Illinois at Urbana-Champaign
-#
-#     http://llvm.org
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy of
-# this software and associated documentation files (the "Software"), to deal with
-# the Software without restriction, including without limitation the rights to
-# use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
-# of the Software, and to permit persons to whom the Software is furnished to do
-# so, subject to the following conditions:
-#
-#     * Redistributions of source code must retain the above copyright notice,
-#       this list of conditions and the following disclaimers.
-#
-#     * Redistributions in binary form must reproduce the above copyright notice,
-#       this list of conditions and the following disclaimers in the
-#       documentation and/or other materials provided with the distribution.
-#
-#     * Neither the names of the LLVM Team, University of Illinois at
-#       Urbana-Champaign, nor the names of its contributors may be used to
-#       endorse or promote products derived from this Software without specific
-#       prior written permission.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-# FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
-# CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE
-# SOFTWARE.
-
-include(CheckCXXSourceCompiles)
-
-# 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})
-  get_directory_property(compile_options COMPILE_OPTIONS)
-  set(CMAKE_REQUIRED_FLAGS ${compile_options})
-  CHECK_CXX_SOURCE_COMPILES("
-#include <atomic>
-int main() {
-  struct Test { int val; };
-  std::atomic<Test> s;
-  s.is_lock_free();
-}" ${varname})
-  set(CMAKE_REQUIRED_FLAGS ${OLD_CMAKE_REQUIRED_FLAGS})
-endfunction(check_working_cxx_atomics)
-
-
-if(NOT DEFINED PROXYGEN_COMPILER_IS_GCC_COMPATIBLE)
-  if(CMAKE_COMPILER_IS_GNUCXX)
-    set(PROXYGEN_COMPILER_IS_GCC_COMPATIBLE ON)
-  elseif(MSVC)
-    set(PROXYGEN_COMPILER_IS_GCC_COMPATIBLE OFF)
-  elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
-    set(PROXYGEN_COMPILER_IS_GCC_COMPATIBLE ON)
-  elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel")
-    set(PROXYGEN_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(PROXYGEN_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()
-      list(APPEND CMAKE_CXX_STANDARD_LIBRARIES -latomic)
-    else()
-      message(FATAL_ERROR "Host compiler appears to require libatomic, but cannot find it.")
-    endif()
-  endif()
-endif()