| ## 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 () |