1 files changed, 78 insertions, 0 deletions
diff --git a/third-party/benchmark/cmake/AddCXXCompilerFlag.cmake b/third-party/benchmark/cmake/AddCXXCompilerFlag.cmake
new file mode 100644
index 000000000000..858589e9775c
--- /dev/null
+++ b/third-party/benchmark/cmake/AddCXXCompilerFlag.cmake
@@ -0,0 +1,78 @@
+# - Adds a compiler flag if it is supported by the compiler
+#
+# This function checks that the supplied compiler flag is supported and then
+# adds it to the corresponding compiler flags
+#
+#  add_cxx_compiler_flag(<FLAG> [<VARIANT>])
+#
+# - Example
+#
+# include(AddCXXCompilerFlag)
+# add_cxx_compiler_flag(-Wall)
+# add_cxx_compiler_flag(-no-strict-aliasing RELEASE)
+# Requires CMake 2.6+
+
+if(__add_cxx_compiler_flag)
+  return()
+endif()
+set(__add_cxx_compiler_flag INCLUDED)
+
+include(CheckCXXCompilerFlag)
+
+function(mangle_compiler_flag FLAG OUTPUT)
+  string(TOUPPER "HAVE_CXX_FLAG_${FLAG}" SANITIZED_FLAG)
+  string(REPLACE "+" "X" SANITIZED_FLAG ${SANITIZED_FLAG})
+  string(REGEX REPLACE "[^A-Za-z_0-9]" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
+  string(REGEX REPLACE "_+" "_" SANITIZED_FLAG ${SANITIZED_FLAG})
+  set(${OUTPUT} "${SANITIZED_FLAG}" PARENT_SCOPE)
+endfunction(mangle_compiler_flag)
+
+function(add_cxx_compiler_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+  if(${MANGLED_FLAG})
+    if(ARGC GREATER 1)
+      set(VARIANT ${ARGV1})
+      string(TOUPPER "_${VARIANT}" VARIANT)
+    else()
+      set(VARIANT "")
+    endif()
+    set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${BENCHMARK_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(add_required_cxx_compiler_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+  if(${MANGLED_FLAG})
+    if(ARGC GREATER 1)
+      set(VARIANT ${ARGV1})
+      string(TOUPPER "_${VARIANT}" VARIANT)
+    else()
+      set(VARIANT "")
+    endif()
+    set(CMAKE_CXX_FLAGS${VARIANT} "${CMAKE_CXX_FLAGS${VARIANT}} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS} ${FLAG}" PARENT_SCOPE)
+    set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} ${FLAG}" PARENT_SCOPE)
+  else()
+    message(FATAL_ERROR "Required flag '${FLAG}' is not supported by the compiler")
+  endif()
+endfunction()
+
+function(check_cxx_warning_flag FLAG)
+  mangle_compiler_flag("${FLAG}" MANGLED_FLAG)
+  set(OLD_CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
+  # Add -Werror to ensure the compiler generates an error if the warning flag
+  # doesn't exist.
+  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror ${FLAG}")
+  check_cxx_compiler_flag("${FLAG}" ${MANGLED_FLAG})
+  set(CMAKE_REQUIRED_FLAGS "${OLD_CMAKE_REQUIRED_FLAGS}")
+endfunction()