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## Copyright (c) 2016 The WebM project authors. All Rights Reserved.
##
## Use of this source code is governed by a BSD-style license
## that can be found in the LICENSE file in the root of the source
## tree. An additional intellectual property rights grant can be found
## in the file PATENTS. All contributing project authors may
## be found in the AUTHORS file in the root of the source tree.
cmake_minimum_required(VERSION 3.2)
include(CheckCXXCompilerFlag)
# String used to cache failed CXX flags.
set(LIBWEBM_FAILED_CXX_FLAGS)
# Checks C++ compiler for support of $cxx_flag. Adds $cxx_flag to
# $CMAKE_CXX_FLAGS when the compile test passes. Caches $c_flag in
# $LIBWEBM_FAILED_CXX_FLAGS when the test fails.
function (add_cxx_flag_if_supported cxx_flag)
unset(CXX_FLAG_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${cxx_flag}" CXX_FLAG_FOUND)
unset(CXX_FLAG_FAILED CACHE)
string(FIND "${LIBWEBM_FAILED_CXX_FLAGS}" "${cxx_flag}" CXX_FLAG_FAILED)
if (${CXX_FLAG_FOUND} EQUAL -1 AND ${CXX_FLAG_FAILED} EQUAL -1)
unset(CXX_FLAG_SUPPORTED CACHE)
message("Checking CXX compiler flag support for: " ${cxx_flag})
check_cxx_compiler_flag("${cxx_flag}" CXX_FLAG_SUPPORTED)
if (CXX_FLAG_SUPPORTED)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${cxx_flag}" CACHE STRING ""
FORCE)
else ()
set(LIBWEBM_FAILED_CXX_FLAGS "${LIBWEBM_FAILED_CXX_FLAGS} ${cxx_flag}"
CACHE STRING "" FORCE)
endif ()
endif ()
endfunction ()
# Checks CXX compiler for support of $cxx_flag and terminates generation when
# support is not present.
function (require_cxx_flag cxx_flag)
unset(CXX_FLAG_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${cxx_flag}" CXX_FLAG_FOUND)
if (${CXX_FLAG_FOUND} EQUAL -1)
unset(LIBWEBM_HAVE_CXX_FLAG CACHE)
message("Checking CXX compiler flag support for: " ${cxx_flag})
check_cxx_compiler_flag("${cxx_flag}" LIBWEBM_HAVE_CXX_FLAG)
if (NOT LIBWEBM_HAVE_CXX_FLAG)
message(FATAL_ERROR
"${PROJECT_NAME} requires support for CXX flag: ${cxx_flag}.")
endif ()
set(CMAKE_CXX_FLAGS "${cxx_flag} ${CMAKE_CXX_FLAGS}" CACHE STRING "" FORCE)
endif ()
endfunction ()
# Checks only non-MSVC targets for support of $cxx_flag.
function (require_cxx_flag_nomsvc cxx_flag)
if (NOT MSVC)
require_cxx_flag(${cxx_flag})
endif ()
endfunction ()
# Adds $preproc_def to CXX compiler command line (as -D$preproc_def) if not
# already present.
function (add_cxx_preproc_definition preproc_def)
unset(PREPROC_DEF_FOUND CACHE)
string(FIND "${CMAKE_CXX_FLAGS}" "${preproc_def}" PREPROC_DEF_FOUND)
if (${PREPROC_DEF_FOUND} EQUAL -1)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D${preproc_def}" CACHE STRING ""
FORCE)
endif ()
endfunction ()