#
# Copyright (c) 2016, Alliance for Open Media. All rights reserved.
#
# This source code is subject to the terms of the BSD 2 Clause License and the
# Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License was
# not distributed with this source code in the LICENSE file, you can obtain it
# at www.aomedia.org/license/software. If the Alliance for Open Media Patent
# License 1.0 was not distributed with this source code in the PATENTS file, you
# can obtain it at www.aomedia.org/license/patent.
#
if(AOM_BUILD_CMAKE_COMPILER_FLAGS_CMAKE_)
return()
endif() # AOM_BUILD_CMAKE_COMPILER_FLAGS_CMAKE_
set(AOM_BUILD_CMAKE_COMPILER_FLAGS_CMAKE_ 1)
include(CheckCCompilerFlag)
include(CheckCXXCompilerFlag)
include("${AOM_ROOT}/build/cmake/compiler_tests.cmake")
# Strings used to cache flags.
set(AOM_C_FLAGS)
set(AOM_CXX_FLAGS)
set(AOM_EXE_LINKER_FLAGS)
set(AOM_FAILED_C_FLAGS)
set(AOM_FAILED_CXX_FLAGS)
# Sets variable named by $out_is_present to YES in the caller's scope when $flag
# is found in the string variable named by $flag_cache. Sets the var to NO
# otherwise.
function(is_flag_present flag_cache flag out_is_present)
string(FIND "${${flag_cache}}" "${flag}" flag_pos)
if(${flag_pos} EQUAL -1)
set(${out_is_present} NO PARENT_SCOPE)
else()
set(${out_is_present} YES PARENT_SCOPE)
endif()
endfunction()
# Appends $flag to $flags. Ignores scope via use of FORCE with set() call.
function(append_flag flags flag)
string(FIND "${${flags}}" "${flag}" found)
if(${found} EQUAL -1)
set(${flags} "${${flags}} ${flag}" CACHE STRING "" FORCE)
endif()
endfunction()
# Checks C compiler for support of $c_flag. Adds $c_flag to all
# $CMAKE_C_FLAGS_<CONFIG>s stored in AOM_C_CONFIGS when the compile test passes.
# Caches $c_flag in $AOM_C_FLAGS or $AOM_FAILED_C_FLAGS depending on test
# outcome.
function(add_c_flag_if_supported c_flag)
if(DEBUG_CMAKE_DISABLE_COMPILER_TESTS)
return()
endif()
is_flag_present(AOM_C_FLAGS "${c_flag}" flag_ok)
is_flag_present(AOM_FAILED_C_FLAGS "${c_flag}" flag_failed)
if(${flag_ok} OR ${flag_failed})
return()
endif()
# Between 3.17.0 and 3.18.2 check_c_compiler_flag() sets a normal variable at
# parent scope while check_cxx_source_compiles() continues to set an internal
# cache variable, so we unset both to avoid the failure / success state
# persisting between checks. See
#
https://gitlab.kitware.com/cmake/cmake/-/issues/21207.
unset(C_FLAG_SUPPORTED)
unset(C_FLAG_SUPPORTED CACHE)
message("Checking C compiler flag support for: " ${c_flag})
check_c_compiler_flag("${c_flag}" C_FLAG_SUPPORTED)
if(${C_FLAG_SUPPORTED})
append_flag(AOM_C_FLAGS "${c_flag}")
foreach(config ${AOM_C_CONFIGS})
unset(C_FLAG_FOUND)
append_flag("${config}" "${c_flag}")
endforeach()
else()
append_flag(AOM_FAILED_C_FLAGS "${c_flag}")
endif()
endfunction()
# Checks C++ compiler for support of $cxx_flag. Adds $cxx_flag to all
# $CMAKE_CXX_FLAGS_<CONFIG>s stored in AOM_CXX_CONFIGS when the compile test
# passes. Caches $cxx_flag in $AOM_CXX_FLAGS or $AOM_FAILED_CXX_FLAGS depending
# on test outcome.
function(add_cxx_flag_if_supported cxx_flag)
if(DEBUG_CMAKE_DISABLE_COMPILER_TESTS)
return()
endif()
is_flag_present(AOM_CXX_FLAGS "${cxx_flag}" flag_ok)
is_flag_present(AOM_FAILED_CXX_FLAGS "${cxx_flag}" flag_failed)
if(${flag_ok} OR ${flag_failed})
return()
endif()
# Between 3.17.0 and 3.18.2 check_cxx_compiler_flag() sets a normal variable
# at parent scope while check_cxx_source_compiles() continues to set an
# internal cache variable, so we unset both to avoid the failure / success
# state persisting between checks. See
#
https://gitlab.kitware.com/cmake/cmake/-/issues/21207.
unset(CXX_FLAG_SUPPORTED)
unset(CXX_FLAG_SUPPORTED CACHE)
message("Checking C++ compiler flag support for: " ${cxx_flag})
check_cxx_compiler_flag("${cxx_flag}" CXX_FLAG_SUPPORTED)
if(${CXX_FLAG_SUPPORTED})
append_flag(AOM_CXX_FLAGS "${cxx_flag}")
foreach(config ${AOM_CXX_CONFIGS})
unset(CXX_FLAG_FOUND)
append_flag("${config}" "${cxx_flag}")
endforeach()
else()
append_flag(AOM_FAILED_CXX_FLAGS "${cxx_flag}")
endif()
endfunction()
# Convenience method for adding a flag to both the C and C++ compiler command
# lines.
function(add_compiler_flag_if_supported flag)
add_c_flag_if_supported(${flag})
add_cxx_flag_if_supported(${flag})
endfunction()
# Checks C compiler for support of $c_flag and terminates generation when
# support is not present.
function(require_c_flag c_flag update_c_flags)
if(DEBUG_CMAKE_DISABLE_COMPILER_TESTS)
return()
endif()
is_flag_present(AOM_C_FLAGS "${c_flag}" flag_ok)
if(${flag_ok})
return()
endif()
if(NOT "${AOM_EXE_LINKER_FLAGS}" STREQUAL "")
aom_push_var(CMAKE_EXE_LINKER_FLAGS "${AOM_EXE_LINKER_FLAGS}")
endif()
unset(HAVE_C_FLAG CACHE)
message("Checking C compiler flag support for: " ${c_flag})
check_c_compiler_flag("${c_flag}" HAVE_C_FLAG)
if(NOT HAVE_C_FLAG)
message(
FATAL_ERROR "${PROJECT_NAME} requires support for C flag: ${c_flag}.")
endif()
if(NOT "${AOM_EXE_LINKER_FLAGS}" STREQUAL "")
aom_pop_var(CMAKE_EXE_LINKER_FLAGS)
endif()
append_flag(AOM_C_FLAGS "${c_flag}")
if(update_c_flags)
foreach(config ${AOM_C_CONFIGS})
set(${config} "${${config}} ${c_flag}" CACHE STRING "" FORCE)
endforeach()
endif()
endfunction()
# Checks CXX compiler for support of $cxx_flag and terminates generation when
# support is not present.
function(require_cxx_flag cxx_flag update_cxx_flags)
if(DEBUG_CMAKE_DISABLE_COMPILER_TESTS)
return()
endif()
is_flag_present(AOM_CXX_FLAGS "${cxx_flag}" flag_ok)
if(${flag_ok})
return()
endif()
if(NOT "${AOM_EXE_LINKER_FLAGS}" STREQUAL "")
aom_push_var(CMAKE_EXE_LINKER_FLAGS "${AOM_EXE_LINKER_FLAGS}")
endif()
unset(HAVE_CXX_FLAG CACHE)
message("Checking C++ compiler flag support for: " ${cxx_flag})
check_cxx_compiler_flag("${cxx_flag}" HAVE_CXX_FLAG)
if(NOT HAVE_CXX_FLAG)
message(
FATAL_ERROR "${PROJECT_NAME} requires support for C++ flag: ${cxx_flag}.")
endif()
if(NOT "${AOM_EXE_LINKER_FLAGS}" STREQUAL "")
aom_pop_var(CMAKE_EXE_LINKER_FLAGS)
endif()
append_flag(AOM_CXX_FLAGS "${cxx_flag}")
if(update_cxx_flags)
foreach(config ${AOM_CXX_CONFIGS})
set(${config} "${${config}} ${cxx_flag}" CACHE STRING "" FORCE)
endforeach()
endif()
endfunction()
# Checks for support of $flag by both the C and CXX compilers. Terminates
# generation when support is not present in both compilers.
function(require_compiler_flag flag update_cmake_flags)
require_c_flag(${flag} ${update_cmake_flags})
require_cxx_flag(${flag} ${update_cmake_flags})
endfunction()
# Checks only non-MSVC targets for support of $c_flag and terminates generation
# when support is not present.
function(require_c_flag_nomsvc c_flag update_c_flags)
if(NOT MSVC)
require_c_flag(${c_flag} ${update_c_flags})
endif()
endfunction()
# Checks only non-MSVC targets for support of $cxx_flag and terminates
# generation when support is not present.
function(require_cxx_flag_nomsvc cxx_flag update_cxx_flags)
if(NOT MSVC)
require_cxx_flag(${cxx_flag} ${update_cxx_flags})
endif()
endfunction()
# Checks only non-MSVC targets for support of $flag by both the C and CXX
# compilers. Terminates generation when support is not present in both
# compilers.
function(require_compiler_flag_nomsvc flag update_cmake_flags)
require_c_flag_nomsvc(${flag} ${update_cmake_flags})
require_cxx_flag_nomsvc(${flag} ${update_cmake_flags})
endfunction()
# Adds $preproc_def to C compiler command line (as -D$preproc_def) if not
# already present.
function(add_c_preproc_definition preproc_def)
set(preproc_def "-D${preproc_def}")
is_flag_present(AOM_C_FLAGS "${preproc_def}" flag_cached)
if(${flag_cached})
return()
endif()
foreach(config ${AOM_C_CONFIGS})
set(${config} "${${config}} ${preproc_def}" CACHE STRING "" FORCE)
endforeach()
endfunction()
# Adds $preproc_def to CXX compiler command line (as -D$preproc_def) if not
# already present.
function(add_cxx_preproc_definition preproc_def)
set(preproc_def "-D${preproc_def}")
is_flag_present(AOM_CXX_FLAGS "${preproc_def}" flag_cached)
if(${flag_cached})
return()
endif()
foreach(config ${AOM_CXX_CONFIGS})
set(${config} "${${config}} ${preproc_def}" CACHE STRING "" FORCE)
endforeach()
endfunction()
# Adds $preproc_def to C and CXX compiler command line (as -D$preproc_def) if
# not already present.
function(add_preproc_definition preproc_def)
add_c_preproc_definition(${preproc_def})
add_cxx_preproc_definition(${preproc_def})
endfunction()
# Adds $flag to assembler command line.
function(append_as_flag flag)
is_flag_present(AOM_AS_FLAGS "${flag}" flag_cached)
if(${flag_cached})
return()
endif()
append_flag(AOM_AS_FLAGS "${flag}")
endfunction()
# Adds $flag to the C compiler command line.
function(append_c_flag flag)
is_flag_present(AOM_C_FLAGS "${flag}" flag_cached)
if(${flag_cached})
return()
endif()
foreach(config ${AOM_C_CONFIGS})
append_flag(${config} "${flag}")
endforeach()
endfunction()
# Adds $flag to the CXX compiler command line.
function(append_cxx_flag flag)
is_flag_present(AOM_CXX_FLAGS "${flag}" flag_cached)
if(${flag_cached})
return()
endif()
foreach(config ${AOM_CXX_CONFIGS})
append_flag(${config} "${flag}")
endforeach()
endfunction()
# Adds $flag to the C and CXX compiler command lines.
function(append_compiler_flag flag)
append_c_flag(${flag})
append_cxx_flag(${flag})
endfunction()
# Adds $flag to the executable linker command line when not present.
function(append_exe_linker_flag flag)
is_flag_present(AOM_EXE_LINKER_FLAGS "${flag}" flag_cached)
if(${flag_cached})
return()
endif()
append_flag(AOM_EXE_LINKER_FLAGS "${flag}")
foreach(config ${AOM_EXE_LINKER_CONFIGS})
append_flag(${config} "${flag}")
endforeach()
endfunction()
# Adds $flag to the link flags for $target.
function(append_link_flag_to_target target flag)
unset(target_link_flags)
get_target_property(target_link_flags ${target} LINK_FLAGS)
if(target_link_flags)
is_flag_present(target_link_flags "${flag}" flag_found)
if(${flag_found})
return()
endif()
set(target_link_flags "${target_link_flags} ${flag}")
else()
set(target_link_flags "${flag}")
endif()
set_target_properties(${target} PROPERTIES LINK_FLAGS ${target_link_flags})
endfunction()
# Adds $flag to executable linker flags, and makes sure C/CXX builds still work.
function(require_linker_flag flag)
if(DEBUG_CMAKE_DISABLE_COMPILER_TESTS)
return()
endif()
append_exe_linker_flag(${flag})
unset(c_passed)
aom_check_c_compiles("LINKER_FLAG_C_TEST(${flag})" "" c_passed)
unset(cxx_passed)
aom_check_cxx_compiles("LINKER_FLAG_CXX_TEST(${flag})" "" cxx_passed)
if(NOT c_passed OR NOT cxx_passed)
message(FATAL_ERROR "Linker flag test for ${flag} failed.")
endif()
endfunction()
# Appends flags in $AOM_EXTRA_<TYPE>_FLAGS variables to the flags used at build
# time.
function(set_user_flags)
# Linker flags are handled first because some C/CXX flags require that a
# linker flag is present at link time.
if(AOM_EXTRA_EXE_LINKER_FLAGS)
is_flag_present(AOM_EXE_LINKER_FLAGS "${AOM_EXTRA_EXE_LINKER_FLAGS}"
extra_present)
if(NOT ${extra_present})
require_linker_flag("${AOM_EXTRA_EXE_LINKER_FLAGS}")
endif()
endif()
if(AOM_EXTRA_AS_FLAGS)
# TODO(tomfinegan): assembler flag testing would be a good thing to have.
is_flag_present(AOM_AS_FLAGS "${AOM_EXTRA_AS_FLAGS}" extra_present)
if(NOT ${extra_present})
append_flag(AOM_AS_FLAGS "${AOM_EXTRA_AS_FLAGS}")
endif()
endif()
if(AOM_EXTRA_C_FLAGS)
is_flag_present(AOM_C_FLAGS "${AOM_EXTRA_C_FLAGS}" extra_present)
if(NOT ${extra_present})
require_c_flag("${AOM_EXTRA_C_FLAGS}" YES)
endif()
endif()
if(AOM_EXTRA_CXX_FLAGS)
is_flag_present(AOM_CXX_FLAGS "${AOM_EXTRA_CXX_FLAGS}" extra_present)
if(NOT ${extra_present})
require_cxx_flag("${AOM_EXTRA_CXX_FLAGS}" YES)
endif()
endif()
endfunction()
