#
# 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.
#
cmake_minimum_required(VERSION 3.5)

if(NOT EMSCRIPTEN)
  if(NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE "Release"
        CACHE "Build type: Debug, Release, RelWithDebInfo or MinSizeRel" STRING
              FORCE)
  endif()
endif()

option(ENABLE_CCACHE "Enable ccache support." OFF)
option(ENABLE_DECODE_PERF_TESTS "Enables decoder performance tests" OFF)
option(ENABLE_DISTCC "Enable distcc support." OFF)
option(ENABLE_DOCS "Enable documentation generation (doxygen required)." ON)
option(ENABLE_ENCODE_PERF_TESTS "Enables encoder performance tests" OFF)
option(ENABLE_EXAMPLES "Enables build of example code." ON)
option(ENABLE_GOMA "Enable goma support." OFF)
option(ENABLE_IDE_TEST_HOSTING
       "Enables running tests within IDEs like Visual Studio and Xcode." OFF)
option(ENABLE_NASM "Use nasm instead of yasm for x86 assembly." OFF)
option(ENABLE_TESTDATA "Enables unit test data download targets." ON)
option(ENABLE_TESTS "Enables unit tests." ON)
option(ENABLE_TOOLS "Enable applications in tools sub directory." ON)
option(ENABLE_WERROR "Converts warnings to errors at compile time." OFF)

# ARM assembly/intrinsics flags.
option(ENABLE_NEON "Enables NEON optimizations on ARM targets." ON)

# MIPS assembly/intrinsics flags.
option(ENABLE_DSPR2 "Enables DSPR2 optimizations on MIPS targets." OFF)
option(ENABLE_MSA "Enables MSA optimizations on MIPS targets." OFF)

# VSX intrinsics flags.
option(ENABLE_VSX "Enables VSX optimizations on PowerPC targets." ON)

# x86/x86_64 assembly/intrinsics flags.
option(ENABLE_MMX "Enables MMX optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSE "Enables SSE optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSE2 "Enables SSE2 optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSE3 "Enables SSE3 optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSSE3 "Enables SSSE3 optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSE4_1 "Enables SSE4_1 optimizations on x86/x86_64 targets." ON)
option(ENABLE_SSE4_2 "Enables SSE4_2 optimizations on x86/x86_64 targets." ON)
option(ENABLE_AVX "Enables AVX optimizations on x86/x86_64 targets." ON)
option(ENABLE_AVX2 "Enables AVX2 optimizations on x86/x86_64 targets." ON)

# $BUILD_SHARED_LIBS is a CMake built-in-- it's listed here for visibility.
option(BUILD_SHARED_LIBS "CMake should generate a shared library build." OFF)

project(AOM C CXX)

set(AOM_ROOT "${CMAKE_CURRENT_SOURCE_DIR}")
set(AOM_CONFIG_DIR "${CMAKE_CURRENT_BINARY_DIR}")
set(INCLUDE_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/include"
    CACHE PATH "Installation path of includes")
set(LIB_INSTALL_DIR "${CMAKE_INSTALL_PREFIX}/lib"
    CACHE PATH "Installation path of libraries")

if("${AOM_ROOT}" STREQUAL "${AOM_CONFIG_DIR}")
  message(FATAL_ERROR
            "Building from within the aom source tree is not supported.\n"
            "Hint: Run these commands\n" "$ rm -rf CMakeCache.txt CMakeFiles\n"
            "$ mkdir -p ../aom_build\n" "$ cd ../aom_build\n"
            "And re-run CMake from the aom_build directory.")
endif()

include("${AOM_ROOT}/build/cmake/aom_configure.cmake")
include("${AOM_ROOT}/aom_dsp/aom_dsp.cmake")
include("${AOM_ROOT}/aom_mem/aom_mem.cmake")
include("${AOM_ROOT}/aom_ports/aom_ports.cmake")
include("${AOM_ROOT}/aom_scale/aom_scale.cmake")
include("${AOM_ROOT}/aom_util/aom_util.cmake")
include("${AOM_ROOT}/av1/av1.cmake")
include("${AOM_ROOT}/test/test.cmake")
include("${AOM_ROOT}/build/cmake/sanitizers.cmake")
include("${AOM_ROOT}/build/cmake/util.cmake")

list(APPEND AOM_RTCD_SOURCES
            "${AOM_CONFIG_DIR}/config/aom_dsp_rtcd.h"
            "${AOM_CONFIG_DIR}/config/aom_scale_rtcd.h"
            "${AOM_CONFIG_DIR}/config/av1_rtcd.h"
            "${AOM_ROOT}/aom_dsp/aom_dsp_rtcd_defs.pl"
            "${AOM_ROOT}/aom_dsp/aom_dsp_rtcd.c"
            "${AOM_ROOT}/aom_scale/aom_scale_rtcd.pl"
            "${AOM_ROOT}/aom_scale/aom_scale_rtcd.c"
            "${AOM_ROOT}/av1/common/av1_rtcd_defs.pl"
            "${AOM_ROOT}/av1/common/av1_rtcd.c"
            "${AOM_ROOT}/build/make/rtcd.pl")

list(APPEND AOM_LIBWEBM_SOURCES
            "${AOM_ROOT}/third_party/libwebm/common/hdr_util.cc"
            "${AOM_ROOT}/third_party/libwebm/common/hdr_util.h"
            "${AOM_ROOT}/third_party/libwebm/common/webmids.h"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvmuxer.cc"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvmuxer.h"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvmuxertypes.h"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvmuxerutil.cc"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvmuxerutil.h"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvwriter.cc"
            "${AOM_ROOT}/third_party/libwebm/mkvmuxer/mkvwriter.h"
            "${AOM_ROOT}/third_party/libwebm/mkvparser/mkvparser.cc"
            "${AOM_ROOT}/third_party/libwebm/mkvparser/mkvparser.h"
            "${AOM_ROOT}/third_party/libwebm/mkvparser/mkvreader.cc"
            "${AOM_ROOT}/third_party/libwebm/mkvparser/mkvreader.h")

list(APPEND AOM_LIBYUV_SOURCES
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/basic_types.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/convert.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/convert_argb.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/convert_from.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/cpu_id.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/planar_functions.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/rotate.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/row.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/scale.h"
            "${AOM_ROOT}/third_party/libyuv/include/libyuv/scale_row.h"
            "${AOM_ROOT}/third_party/libyuv/source/cpu_id.cc"
            "${AOM_ROOT}/third_party/libyuv/source/planar_functions.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_any.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_common.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_gcc.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_mips.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_neon.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_neon64.cc"
            "${AOM_ROOT}/third_party/libyuv/source/row_win.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_any.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_common.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_gcc.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_mips.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_neon.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_neon64.cc"
            "${AOM_ROOT}/third_party/libyuv/source/scale_win.cc")

list(APPEND AOM_SOURCES
            "${AOM_CONFIG_DIR}/config/aom_config.c"
            "${AOM_CONFIG_DIR}/config/aom_config.h"
            "${AOM_ROOT}/aom/aom.h"
            "${AOM_ROOT}/aom/aom_codec.h"
            "${AOM_ROOT}/aom/aom_decoder.h"
            "${AOM_ROOT}/aom/aom_encoder.h"
            "${AOM_ROOT}/aom/aom_frame_buffer.h"
            "${AOM_ROOT}/aom/aom_image.h"
            "${AOM_ROOT}/aom/aom_integer.h"
            "${AOM_ROOT}/aom/aomcx.h"
            "${AOM_ROOT}/aom/aomdx.h"
            "${AOM_ROOT}/aom/internal/aom_codec_internal.h"
            "${AOM_ROOT}/aom/src/aom_codec.c"
            "${AOM_ROOT}/aom/src/aom_decoder.c"
            "${AOM_ROOT}/aom/src/aom_encoder.c"
            "${AOM_ROOT}/aom/src/aom_image.c"
            "${AOM_ROOT}/aom/src/aom_integer.c")

list(APPEND AOM_COMMON_APP_UTIL_SOURCES "${AOM_ROOT}/common/args.c"
            "${AOM_ROOT}/common/args.h" "${AOM_ROOT}/common/md5_utils.c"
            "${AOM_ROOT}/common/md5_utils.h"
            "${AOM_ROOT}/common/tools_common.c"
            "${AOM_ROOT}/common/tools_common.h"
            "${AOM_ROOT}/common/video_common.h" "${AOM_ROOT}/common/y4menc.c"
            "${AOM_ROOT}/common/y4menc.h")

list(APPEND AOM_DECODER_APP_UTIL_SOURCES "${AOM_ROOT}/common/ivfdec.c"
            "${AOM_ROOT}/common/ivfdec.h" "${AOM_ROOT}/common/obudec.c"
            "${AOM_ROOT}/common/obudec.h" "${AOM_ROOT}/common/video_reader.c"
            "${AOM_ROOT}/common/video_reader.h")

list(APPEND AOM_ENCODER_APP_UTIL_SOURCES
            "${AOM_ROOT}/common/ivfenc.c"
            "${AOM_ROOT}/common/ivfenc.h"
            "${AOM_ROOT}/common/video_writer.c"
            "${AOM_ROOT}/common/video_writer.h"
            "${AOM_ROOT}/common/warnings.c"
            "${AOM_ROOT}/common/warnings.h"
            "${AOM_ROOT}/common/y4minput.c"
            "${AOM_ROOT}/common/y4minput.h"
            "${AOM_ROOT}/examples/encoder_util.h"
            "${AOM_ROOT}/examples/encoder_util.c")

list(APPEND AOM_ENCODER_STATS_SOURCES "${AOM_ROOT}/stats/aomstats.c"
            "${AOM_ROOT}/stats/aomstats.h" "${AOM_ROOT}/stats/rate_hist.c"
            "${AOM_ROOT}/stats/rate_hist.h")

list(APPEND AOM_PKG_CONFIG_SOURCES "${AOM_CONFIG_DIR}/aom.pc")

list(APPEND AOM_VERSION_SOURCES "${AOM_CONFIG_DIR}/config/aom_version.h")

list(APPEND AOM_WEBM_DECODER_SOURCES "${AOM_ROOT}/common/webmdec.cc"
            "${AOM_ROOT}/common/webmdec.h")

list(APPEND AOM_WEBM_ENCODER_SOURCES "${AOM_ROOT}/common/webmenc.cc"
            "${AOM_ROOT}/common/webmenc.h")

include_directories(${AOM_ROOT} ${AOM_CONFIG_DIR} ${AOM_ROOT}/apps
                    ${AOM_ROOT}/common ${AOM_ROOT}/examples ${AOM_ROOT}/stats)

# Targets
add_library(aom_version ${AOM_VERSION_SOURCES})
add_dummy_source_file_to_target(aom_version c)
add_custom_command(OUTPUT "${AOM_CONFIG_DIR}/config/aom_version.h"
                   COMMAND ${CMAKE_COMMAND} ARGS
                           -DAOM_CONFIG_DIR=${AOM_CONFIG_DIR}
                           -DAOM_ROOT=${AOM_ROOT}
                           -DGIT_EXECUTABLE=${GIT_EXECUTABLE}
                           -DPERL_EXECUTABLE=${PERL_EXECUTABLE} -P
                           "${AOM_ROOT}/build/cmake/version.cmake"
                   COMMENT "Writing aom_version.h" VERBATIM)

add_custom_target(aom_version_check
                  COMMAND ${CMAKE_COMMAND} -DAOM_CONFIG_DIR=${AOM_CONFIG_DIR}
                          -DAOM_ROOT=${AOM_ROOT}
                          -DGIT_EXECUTABLE=${GIT_EXECUTABLE}
                          -DPERL_EXECUTABLE=${PERL_EXECUTABLE} -P
                          "${AOM_ROOT}/build/cmake/version.cmake"
                  COMMENT "Updating version info if necessary." VERBATIM)
add_dependencies(aom_version aom_version_check)

if(NOT MSVC)
  add_library(aom_pc ${AOM_PKG_CONFIG_SOURCES})
  add_dummy_source_file_to_target(aom_pc c)
  add_custom_command(OUTPUT "${AOM_CONFIG_DIR}/aom.pc"
                     COMMAND ${CMAKE_COMMAND} ARGS
                             -DAOM_CONFIG_DIR=${AOM_CONFIG_DIR}
                             -DAOM_ROOT=${AOM_ROOT}
                             -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
                             -DCMAKE_PROJECT_NAME=${CMAKE_PROJECT_NAME}
                             -DCONFIG_MULTITHREAD=${CONFIG_MULTITHREAD}
                             -DHAVE_PTHREAD_H=${HAVE_PTHREAD_H} -P
                             "${AOM_ROOT}/build/cmake/pkg_config.cmake"
                     COMMENT "Writing aom.pc" VERBATIM)
  add_dependencies(aom_pc aom_version)
endif()

# TODO(tomfinegan): Move rtcd target setup where it belongs for each rtcd
# source.
add_rtcd_build_step("${AOM_ROOT}/aom_dsp/aom_dsp_rtcd_defs.pl"
                    "${AOM_CONFIG_DIR}/config/aom_dsp_rtcd.h"
                    "${AOM_ROOT}/aom_dsp/aom_dsp_rtcd.c" "aom_dsp_rtcd")
add_rtcd_build_step("${AOM_ROOT}/aom_scale/aom_scale_rtcd.pl"
                    "${AOM_CONFIG_DIR}/config/aom_scale_rtcd.h"
                    "${AOM_ROOT}/aom_scale/aom_scale_rtcd.c" "aom_scale_rtcd")
add_rtcd_build_step("${AOM_ROOT}/av1/common/av1_rtcd_defs.pl"
                    "${AOM_CONFIG_DIR}/config/av1_rtcd.h"
                    "${AOM_ROOT}/av1/common/av1_rtcd.c" "av1_rtcd")

add_library(aom_rtcd OBJECT ${AOM_RTCD_SOURCES})
add_dependencies(aom_rtcd aom_version)

add_library(aom_encoder_stats OBJECT ${AOM_ENCODER_STATS_SOURCES})
add_library(aom ${AOM_SOURCES} $<TARGET_OBJECTS:aom_rtcd>)

if(NOT MSVC AND NOT APPLE)
  target_link_libraries(aom ${AOM_LIB_LINK_TYPE} m)
endif()

# List of object and static library targets.
set(AOM_LIB_TARGETS ${AOM_LIB_TARGETS} aom_rtcd aom_encoder_stats aom_mem
    aom_scale aom)

# Setup dependencies.
setup_aom_dsp_targets()
setup_aom_mem_targets()
setup_aom_ports_targets()
setup_aom_util_targets()
setup_aom_scale_targets()
setup_av1_targets()

# Make all library targets depend on aom_rtcd to make sure it builds first.
foreach(aom_lib ${AOM_LIB_TARGETS})
  if(NOT "${aom_lib}" STREQUAL "aom_rtcd")
    add_dependencies(${aom_lib} aom_rtcd)
  endif()
endforeach()

# Generate C/C++ stub files containing the function usage_exit(). Users of the
# aom_common_app_util library must define this function. This is a convenience
# to allow omission of the function from applications that might want to use
# other pieces of the util support without defining usage_exit().
file(WRITE "${AOM_CONFIG_DIR}/usage_exit.c" "void usage_exit(void) {}")
file(WRITE "${AOM_CONFIG_DIR}/usage_exit.cc"
           "extern \"C\" void usage_exit(void) {}")

#
# Application and application support targets.
#
if(ENABLE_EXAMPLES OR ENABLE_TESTS OR ENABLE_TOOLS)
  add_library(aom_common_app_util OBJECT ${AOM_COMMON_APP_UTIL_SOURCES})
  if(CONFIG_AV1_DECODER)
    add_library(aom_decoder_app_util OBJECT ${AOM_DECODER_APP_UTIL_SOURCES})
    # obudec depends on internal headers that require *rtcd.h
    add_dependencies(aom_decoder_app_util aom_rtcd)
  endif()
  if(CONFIG_AV1_ENCODER)
    add_library(aom_encoder_app_util OBJECT ${AOM_ENCODER_APP_UTIL_SOURCES})
  endif()
endif()

if((CONFIG_AV1_DECODER OR CONFIG_AV1_ENCODER) AND ENABLE_EXAMPLES)
  add_executable(resize_util "${AOM_ROOT}/examples/resize_util.c"
                 $<TARGET_OBJECTS:aom_common_app_util>)
  list(APPEND AOM_APP_TARGETS resize_util)
endif()

if(CONFIG_AV1_DECODER AND ENABLE_EXAMPLES)
  add_executable(aomdec "${AOM_ROOT}/apps/aomdec.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  add_executable(decode_to_md5 "${AOM_ROOT}/examples/decode_to_md5.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  add_executable(decode_with_drops "${AOM_ROOT}/examples/decode_with_drops.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  add_executable(simple_decoder "${AOM_ROOT}/examples/simple_decoder.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  add_executable(scalable_decoder "${AOM_ROOT}/examples/scalable_decoder.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)

  if(CONFIG_ANALYZER)
    add_executable(analyzer "${AOM_ROOT}/examples/analyzer.cc"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_decoder_app_util>)
    target_link_libraries(analyzer ${AOM_LIB_LINK_TYPE} ${wxWidgets_LIBRARIES})
    list(APPEND AOM_APP_TARGETS analyzer)
    list(APPEND AOM_DECODER_EXAMPLE_TARGETS analyzer)
  endif()

  if(CONFIG_INSPECTION)
    add_executable(inspect "${AOM_ROOT}/examples/inspect.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_decoder_app_util>)
    list(APPEND AOM_DECODER_EXAMPLE_TARGETS inspect)

    if(EMSCRIPTEN)
      add_preproc_definition(_POSIX_SOURCE)
      append_link_flag_to_target("inspect" "-s TOTAL_MEMORY=402653184")
      append_link_flag_to_target("inspect" "-s MODULARIZE=1")
      append_link_flag_to_target(
        "inspect" "-s \'EXTRA_EXPORTED_RUNTIME_METHODS=[\"UTF8ToString\"]\'")
      append_link_flag_to_target("inspect"
                                 "-s EXPORT_NAME=\"\'DecoderModule\'\"")
      append_link_flag_to_target("inspect" "--memory-init-file 0")

      if("${CMAKE_BUILD_TYPE}" STREQUAL "")

        # Default to -O3 when no build type is specified.
        append_compiler_flag("-O3")
      endif()

      em_link_post_js(inspect "${AOM_ROOT}/tools/inspect-post.js")
    endif()
  endif()

  # Maintain a list of decoder example targets.
  list(APPEND AOM_DECODER_EXAMPLE_TARGETS aomdec decode_to_md5
              decode_with_drops scalable_decoder simple_decoder)

  # Add decoder examples to the app targets list.
  list(APPEND AOM_APP_TARGETS ${AOM_DECODER_EXAMPLE_TARGETS})
endif()

if(CONFIG_AV1_ENCODER)
  if(ENABLE_EXAMPLES)
    add_executable(aomenc "${AOM_ROOT}/apps/aomenc.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>
                   $<TARGET_OBJECTS:aom_encoder_stats>)
    add_executable(lossless_encoder "${AOM_ROOT}/examples/lossless_encoder.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)
    add_executable(set_maps "${AOM_ROOT}/examples/set_maps.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)
    add_executable(simple_encoder "${AOM_ROOT}/examples/simple_encoder.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)
    add_executable(twopass_encoder "${AOM_ROOT}/examples/twopass_encoder.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)
    add_executable(noise_model "${AOM_ROOT}/examples/noise_model.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)
    add_executable(scalable_encoder "${AOM_ROOT}/examples/scalable_encoder.c"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_encoder_app_util>)

    # Maintain a list of encoder example targets.
    list(APPEND AOM_ENCODER_EXAMPLE_TARGETS aomenc lossless_encoder noise_model
                set_maps simple_encoder scalable_encoder twopass_encoder)
  endif()

  if(ENABLE_TOOLS)
    if(CONFIG_ENTROPY_STATS AND NOT BUILD_SHARED_LIBS)

      # TODO(tomfinegan): Sort out why a simple link command with
      # aom_entropy_optimizer.c won't work on macos, but dragging in all the
      # helper machinery allows the link to succeed.
      add_executable(aom_entropy_optimizer "${AOM_CONFIG_DIR}/usage_exit.c"
                     "${AOM_ROOT}/tools/aom_entropy_optimizer.c"
                     $<TARGET_OBJECTS:aom_common_app_util>
                     $<TARGET_OBJECTS:aom_encoder_app_util>)

      # Maintain a list of encoder tool targets.
      list(APPEND AOM_ENCODER_TOOL_TARGETS aom_entropy_optimizer)
    endif()
  endif()

  # Add encoder examples and tools to the targets list.
  list(APPEND AOM_APP_TARGETS ${AOM_ENCODER_EXAMPLE_TARGETS}
              ${AOM_ENCODER_TOOL_TARGETS})
endif()

if(ENABLE_EXAMPLES)

  # Maintain a separate variable listing only the examples to facilitate
  # installation of example programs into an examples sub directory of
  # $AOM_DIST_DIR/bin when building the dist target.
  list(APPEND AOM_EXAMPLE_TARGETS ${AOM_DECODER_EXAMPLE_TARGETS}
              ${AOM_ENCODER_EXAMPLE_TARGETS})
endif()

if(ENABLE_TOOLS)
  if(CONFIG_AV1_DECODER)
    require_cxx_flag_nomsvc("-std=c++11" NO)
    add_executable(dump_obu "${AOM_CONFIG_DIR}/usage_exit.cc"
                   "${AOM_ROOT}/tools/dump_obu.cc"
                   "${AOM_ROOT}/tools/obu_parser.cc"
                   "${AOM_ROOT}/tools/obu_parser.h"
                   $<TARGET_OBJECTS:aom_common_app_util>
                   $<TARGET_OBJECTS:aom_decoder_app_util>)

    list(APPEND AOM_TOOL_TARGETS dump_obu)
    list(APPEND AOM_APP_TARGETS dump_obu)

    if(NOT MSVC)
      target_compile_options(dump_obu PUBLIC -std=c++11)
    endif()

    # Maintain a separate variable listing only the examples to facilitate
    # installation of example programs into an tools sub directory of
    # $AOM_DIST_DIR/bin when building the dist target.
    list(APPEND AOM_TOOL_TARGETS ${AOM_DECODER_TOOL_TARGETS}
                ${AOM_ENCODER_TOOL_TARGETS})
  endif()
endif()

if(ENABLE_EXAMPLES AND CONFIG_AV1_DECODER AND CONFIG_AV1_ENCODER)
  add_executable(aom_cx_set_ref "${AOM_ROOT}/examples/aom_cx_set_ref.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_encoder_app_util>)
  list(APPEND AOM_EXAMPLE_TARGETS aom_cx_set_ref)
  list(APPEND AOM_APP_TARGETS aom_cx_set_ref)
endif()

if(ENABLE_EXAMPLES AND CONFIG_AV1_ENCODER)
  add_executable(lightfield_encoder "${AOM_ROOT}/examples/lightfield_encoder.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_encoder_app_util>)
  list(APPEND AOM_EXAMPLE_TARGETS lightfield_encoder)
  list(APPEND AOM_APP_TARGETS lightfield_encoder)
endif()

if(ENABLE_EXAMPLES AND CONFIG_AV1_DECODER)
  add_executable(lightfield_tile_list_decoder
                 "${AOM_ROOT}/examples/lightfield_tile_list_decoder.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  list(APPEND AOM_EXAMPLE_TARGETS lightfield_tile_list_decoder)
  list(APPEND AOM_APP_TARGETS lightfield_tile_list_decoder)
endif()

if(ENABLE_EXAMPLES AND CONFIG_AV1_DECODER)
  add_executable(lightfield_decoder "${AOM_ROOT}/examples/lightfield_decoder.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  list(APPEND AOM_EXAMPLE_TARGETS lightfield_decoder)
  list(APPEND AOM_APP_TARGETS lightfield_decoder)
endif()

if(ENABLE_EXAMPLES AND CONFIG_AV1_ENCODER AND CONFIG_AV1_DECODER)
  add_executable(lightfield_bitstream_parsing
                 "${AOM_ROOT}/examples/lightfield_bitstream_parsing.c"
                 $<TARGET_OBJECTS:aom_common_app_util>
                 $<TARGET_OBJECTS:aom_encoder_app_util>
                 $<TARGET_OBJECTS:aom_decoder_app_util>)
  list(APPEND AOM_EXAMPLE_TARGETS lightfield_bitstream_parsing)
  list(APPEND AOM_APP_TARGETS lightfield_bitstream_parsing)
endif()

foreach(aom_app ${AOM_APP_TARGETS})
  target_link_libraries(${aom_app} ${AOM_LIB_LINK_TYPE} aom)
endforeach()

if(ENABLE_EXAMPLES OR ENABLE_TESTS OR ENABLE_TOOLS)
  if(CONFIG_LIBYUV)
    add_library(yuv OBJECT ${AOM_LIBYUV_SOURCES})
    if(NOT MSVC)
      target_compile_options(yuv PRIVATE -Wno-unused-parameter)
    endif()
    include_directories("${AOM_ROOT}/third_party/libyuv/include")

    # Add to existing targets.
    foreach(aom_app ${AOM_APP_TARGETS})
      target_sources(${aom_app} PRIVATE $<TARGET_OBJECTS:yuv>)
      set_property(TARGET ${aom_app} PROPERTY LINKER_LANGUAGE CXX)
    endforeach()
  endif()

  if(CONFIG_WEBM_IO)
    require_cxx_flag_nomsvc("-std=c++11" NO)

    add_library(webm OBJECT ${AOM_LIBWEBM_SOURCES})
    include_directories("${AOM_ROOT}/third_party/libwebm")
    target_compile_definitions(webm PRIVATE __STDC_CONSTANT_MACROS)
    target_compile_definitions(webm PRIVATE __STDC_LIMIT_MACROS)

    if(NOT MSVC)
      target_compile_options(webm PRIVATE -Wno-shadow)
      target_compile_options(webm PUBLIC -std=c++11)
    endif()

    # Add to existing targets.
    if(CONFIG_AV1_DECODER)
      target_sources(aom_decoder_app_util PRIVATE ${AOM_WEBM_DECODER_SOURCES})
    endif()

    if(CONFIG_AV1_ENCODER)
      target_sources(aom_encoder_app_util PRIVATE ${AOM_WEBM_ENCODER_SOURCES})
    endif()

    foreach(aom_app ${AOM_APP_TARGETS})
      target_sources(${aom_app} PRIVATE $<TARGET_OBJECTS:webm>)
      set_property(TARGET ${aom_app} PROPERTY LINKER_LANGUAGE CXX)
    endforeach()
  endif()
endif()

if(ENABLE_TESTS)

  # Create test_libaom target and the targets it depends on.
  setup_aom_test_targets()
endif()

if(HAVE_PTHREAD_H AND CONFIG_MULTITHREAD)
  find_package(Threads)
  foreach(app_target ${AOM_APP_TARGETS})
    target_link_libraries(${app_target} ${AOM_LIB_LINK_TYPE} Threads::Threads)
  endforeach()
endif()

if(XCODE)

  # TODO(tomfinegan): Make sure target has no C++ files before doing this as
  # it's not necessary in that case.
  if(CONFIG_LIBYUV OR CONFIG_WEBM_IO)

    # The Xcode generator does not obey LINKER_LANGUAGE. Because of the issue
    # what looks like a C++ file needs to be in any target that Xcode will link
    # when the target contains a C++ dependency. Without this Xcode will try to
    # link with the C linker, which always ends badly when a dependency actually
    # includes C++.

    # Note: LINKER_LANGUAGE is explicitly set to C++ for all targets touched
    # here, it really is the Xcode generator's fault, or just a deficiency in
    # Xcode itself.
    foreach(aom_app ${AOM_APP_TARGETS})
      add_dummy_source_file_to_target("${aom_app}" "cc")
    endforeach()
  endif()
endif()

if(ENABLE_EXAMPLES AND "${CMAKE_GENERATOR}" MATCHES "Makefiles$")

  # For historical purposes place the example binaries in the example directory.
  file(MAKE_DIRECTORY "${AOM_CONFIG_DIR}/examples")

  foreach(target ${AOM_EXAMPLE_TARGETS})
    if(NOT "${target}" MATCHES "aomdec\|aomenc")
      set_target_properties(${target}
                            PROPERTIES RUNTIME_OUTPUT_DIRECTORY
                                       "${AOM_CONFIG_DIR}/examples")
    endif()
  endforeach()

  if(ENABLE_TOOLS AND AOM_TOOL_TARGETS)

    # The same expectation is true for tool targets.
    file(MAKE_DIRECTORY "${AOM_CONFIG_DIR}/tools")
    set_target_properties(${AOM_TOOL_TARGETS}
                          PROPERTIES RUNTIME_OUTPUT_DIRECTORY
                                     "${AOM_CONFIG_DIR}/tools")
  endif()
endif()

if(BUILD_SHARED_LIBS)
  include("${AOM_ROOT}/build/cmake/exports.cmake")
  setup_exports_target()
  set_target_properties(aom PROPERTIES SOVERSION 0)
endif()

# Handle user supplied compile and link flags last to ensure they're obeyed.
set_user_flags()

# Aomedia documentation rule.
if(ENABLE_DOCS)
  include(FindDoxygen)
  if(DOXYGEN_FOUND)
    include("${AOM_ROOT}/docs.cmake")
    setup_documentation_targets()
  else()
    message("--- Cannot find doxygen, ENABLE_DOCS turned off.")
    set(ENABLE_DOCS OFF)
  endif()
endif()

if(NOT (MSVC OR XCODE))

  # Aomedia install rule.
  list(APPEND AOM_INSTALL_INCS "${AOM_ROOT}/aom/aom.h"
              "${AOM_ROOT}/aom/aom_codec.h"
              "${AOM_ROOT}/aom/aom_frame_buffer.h"
              "${AOM_ROOT}/aom/aom_image.h" "${AOM_ROOT}/aom/aom_integer.h"
              "${AOM_ROOT}/aom/aom.h")

  if(CONFIG_AV1_DECODER)
    if(ENABLE_EXAMPLES)
      list(APPEND AOM_INSTALL_BINS aomdec)
    endif()

    list(APPEND AOM_INSTALL_INCS "${AOM_ROOT}/aom/aom_decoder.h"
                "${AOM_ROOT}/aom/aomdx.h")
  endif()

  if(CONFIG_AV1_ENCODER)
    if(ENABLE_EXAMPLES)
      list(APPEND AOM_INSTALL_BINS aomenc)
    endif()

    list(APPEND AOM_INSTALL_INCS "${AOM_ROOT}/aom/aomcx.h"
                "${AOM_ROOT}/aom/aom_encoder.h")
  endif()

  set(AOM_INSTALL_LIBS aom)

  install(FILES ${AOM_INSTALL_INCS} DESTINATION "${INCLUDE_INSTALL_DIR}/aom")
  install(FILES "${AOM_CONFIG_DIR}/aom.pc" DESTINATION
                "${LIB_INSTALL_DIR}/pkgconfig")
  install(TARGETS ${AOM_INSTALL_LIBS} DESTINATION "${LIB_INSTALL_DIR}")

  if(ENABLE_EXAMPLES)
    install(TARGETS ${AOM_INSTALL_BINS} DESTINATION
                    "${CMAKE_INSTALL_PREFIX}/bin")
  endif()
endif()

# Aomedia dist rule.
if(CONFIG_AV1_DECODER AND ENABLE_EXAMPLES)
  list(APPEND AOM_DIST_APPS $<TARGET_FILE:aomdec>)
endif()
if(CONFIG_AV1_ENCODER AND ENABLE_EXAMPLES)
  list(APPEND AOM_DIST_APPS $<TARGET_FILE:aomenc>)
endif()

if(ENABLE_EXAMPLES)
  foreach(example ${AOM_EXAMPLE_TARGETS})
    list(APPEND AOM_DIST_EXAMPLES $<TARGET_FILE:${example}>)
  endforeach()
endif()

if(ENABLE_TOOLS)
  foreach(tool ${AOM_TOOL_TARGETS})
    list(APPEND AOM_DIST_TOOLS $<TARGET_FILE:${tool}>)
  endforeach()
endif()

if(NOT AOM_DIST_DIR)
  set(AOM_DIST_DIR "${AOM_CONFIG_DIR}/dist")
endif()

add_custom_target(dist
                  COMMAND ${CMAKE_COMMAND} -DAOM_ROOT=${AOM_ROOT}
                          -DAOM_CONFIG_DIR=${AOM_CONFIG_DIR}
                          -DAOM_DIST_DIR=${AOM_DIST_DIR}
                          -DAOM_DIST_APPS="${AOM_DIST_APPS}"
                          -DAOM_DIST_EXAMPLES="${AOM_DIST_EXAMPLES}"
                          -DAOM_DIST_TOOLS="${AOM_DIST_TOOLS}"
                          -DAOM_DIST_INCLUDES="${AOM_INSTALL_INCS}"
                          -DAOM_DIST_LIBS=$<TARGET_FILE:aom>
                          -DENABLE_DOCS=${ENABLE_DOCS} -P
                          "${AOM_ROOT}/build/cmake/dist.cmake"
                  DEPENDS ${AOM_INSTALL_BINS} ${AOM_INSTALL_LIBS}
                          ${AOM_INSTALL_INCS} ${AOM_EXAMPLE_TARGETS}
                          ${AOM_TOOL_TARGETS})

if(ENABLE_DOCS)
  add_dependencies(dist docs)
endif()

# Collect all variables containing libaom source files.
get_cmake_property(all_cmake_vars VARIABLES)
foreach(var ${all_cmake_vars})
  if("${var}" MATCHES "SOURCES$\|_INTRIN_\|_ASM_" AND NOT "${var}" MATCHES
     "_APP_\|DOXYGEN\|LIBWEBM\|LIBYUV\|_PKG_\|TEST")
    list(APPEND aom_source_vars ${var})
  endif()
endforeach()

# Libaom_srcs.txt generation.
set(libaom_srcs_txt_file "${AOM_CONFIG_DIR}/libaom_srcs.txt")
file(WRITE "${libaom_srcs_txt_file}" "# This file is generated. DO NOT EDIT.\n")

# Static source file list first.
foreach(aom_source_var ${aom_source_vars})
  foreach(file ${${aom_source_var}})
    if(NOT "${file}" MATCHES "${AOM_CONFIG_DIR}")
      string(REPLACE "${AOM_ROOT}/" "" file "${file}")
      file(APPEND "${libaom_srcs_txt_file}" "${file}\n")
    endif()
  endforeach()
endforeach()

file(APPEND
       "${libaom_srcs_txt_file}"
       "# Files below this line are generated by the libaom build system.\n")
foreach(aom_source_var ${aom_source_vars})
  foreach(file ${${aom_source_var}})
    if("${file}" MATCHES "${AOM_CONFIG_DIR}")
      string(REPLACE "${AOM_CONFIG_DIR}/" "" file "${file}")
      file(APPEND "${libaom_srcs_txt_file}" "${file}\n")
    endif()
  endforeach()
endforeach()

# Libaom_srcs.gni generation.
set(libaom_srcs_gni_file "${AOM_CONFIG_DIR}/libaom_srcs.gni")
file(WRITE "${libaom_srcs_gni_file}" "# This file is generated. DO NOT EDIT.\n")

foreach(aom_source_var ${aom_source_vars})
  if("${${aom_source_var}}" MATCHES "${AOM_ROOT}")
    string(TOLOWER ${aom_source_var} aom_source_var_lowercase)
    file(APPEND "${libaom_srcs_gni_file}" "\n${aom_source_var_lowercase} = [\n")
  endif()

  foreach(file ${${aom_source_var}})
    if(NOT "${file}" MATCHES "${AOM_CONFIG_DIR}")
      string(REPLACE "${AOM_ROOT}" "//third_party/libaom/source/libaom" file
                     "${file}")
      file(APPEND "${libaom_srcs_gni_file}" "  \"${file}\",\n")
    endif()
  endforeach()

  if("${${aom_source_var}}" MATCHES "${AOM_ROOT}")
    file(APPEND "${libaom_srcs_gni_file}" "]\n")
  endif()
endforeach()

file(APPEND
       "${libaom_srcs_gni_file}"
       "\n# Files below this line are generated by the libaom build system.\n")

foreach(aom_source_var ${aom_source_vars})
  if("${${aom_source_var}}" MATCHES "${AOM_CONFIG_DIR}")
    string(TOLOWER ${aom_source_var} aom_source_var_lowercase)
    file(APPEND "${libaom_srcs_gni_file}"
                "\n${aom_source_var_lowercase}_gen = [\n")
  endif()
  foreach(file ${${aom_source_var}})
    if(NOT "${file}" MATCHES "${AOM_ROOT}")
      string(REPLACE "${AOM_CONFIG_DIR}" "//third_party/libaom/source/libaom"
                     file "${file}")
      file(APPEND "${libaom_srcs_gni_file}" "  \"${file}\",\n")
    endif()
  endforeach()

  if("${${aom_source_var}}" MATCHES "${AOM_CONFIG_DIR}")
    file(APPEND "${libaom_srcs_gni_file}" "]\n")
  endif()
endforeach()