blender/build_files/cmake/platform/platform_unix.cmake

# ***** BEGIN GPL LICENSE BLOCK *****
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
# The Original Code is Copyright (C) 2016, Blender Foundation
# All rights reserved.
# ***** END GPL LICENSE BLOCK *****

# Libraries configuration for any *nix system including Linux and Unix.

# Detect precompiled library directory
if(NOT DEFINED LIBDIR)
  # Path to a locally compiled libraries.
  set(LIBDIR_NAME ${CMAKE_SYSTEM_NAME}_${CMAKE_SYSTEM_PROCESSOR})
  string(TOLOWER ${LIBDIR_NAME} LIBDIR_NAME)
  set(LIBDIR_NATIVE_ABI ${CMAKE_SOURCE_DIR}/../lib/${LIBDIR_NAME})

  # Path to precompiled libraries with known CentOS 7 ABI.
  set(LIBDIR_CENTOS7_ABI ${CMAKE_SOURCE_DIR}/../lib/linux_centos7_x86_64)

  # Choose the best suitable libraries.
  if(EXISTS ${LIBDIR_NATIVE_ABI})
    set(LIBDIR ${LIBDIR_NATIVE_ABI})
  elseif(EXISTS ${LIBDIR_CENTOS7_ABI})
    set(LIBDIR ${LIBDIR_CENTOS7_ABI})
    set(WITH_CXX11_ABI OFF)

    if(CMAKE_COMPILER_IS_GNUCC AND
       CMAKE_C_COMPILER_VERSION VERSION_LESS 9.3)
      message(FATAL_ERROR "GCC version must be at least 9.3 for precompiled libraries, found ${CMAKE_C_COMPILER_VERSION}")
    endif()
  endif()

  # Avoid namespace pollustion.
  unset(LIBDIR_NATIVE_ABI)
  unset(LIBDIR_CENTOS7_ABI)
endif()

if(EXISTS ${LIBDIR})
  message(STATUS "Using pre-compiled LIBDIR: ${LIBDIR}")

  file(GLOB LIB_SUBDIRS ${LIBDIR}/*)
  # Ignore Mesa software OpenGL libraries, they are not intended to be
  # linked against but to optionally override at runtime.
  list(REMOVE_ITEM LIB_SUBDIRS ${LIBDIR}/mesa)
  # NOTE: Make sure "proper" compiled zlib comes first before the one
  # which is a part of OpenCollada. They have different ABI, and we
  # do need to use the official one.
  set(CMAKE_PREFIX_PATH ${LIBDIR}/zlib ${LIB_SUBDIRS})
  set(WITH_STATIC_LIBS ON)
  # OpenMP usually can't be statically linked into shared libraries,
  # due to not being compiled with position independent code.
  if(NOT WITH_PYTHON_MODULE)
    set(WITH_OPENMP_STATIC ON)
  endif()
  set(Boost_NO_BOOST_CMAKE ON)
  set(BOOST_ROOT ${LIBDIR}/boost)
  set(BOOST_LIBRARYDIR ${LIBDIR}/boost/lib)
  set(Boost_NO_SYSTEM_PATHS ON)
  set(OPENEXR_ROOT_DIR ${LIBDIR}/openexr)
  set(CLANG_ROOT_DIR ${LIBDIR}/llvm)
endif()

if(WITH_STATIC_LIBS)
  string(APPEND CMAKE_EXE_LINKER_FLAGS " -static-libstdc++")
endif()

# Wrapper to prefer static libraries
macro(find_package_wrapper)
  if(WITH_STATIC_LIBS)
    find_package_static(${ARGV})
  else()
    find_package(${ARGV})
  endif()
endmacro()

# ----------------------------------------------------------------------------
# Precompiled Libraries
#
# These are libraries that may be precompiled. For this we disable searching in
# the system directories so that we don't accidentally use them instead.

if(EXISTS ${LIBDIR})
  without_system_libs_begin()
endif()

find_package_wrapper(JPEG REQUIRED)
find_package_wrapper(PNG REQUIRED)
find_package_wrapper(ZLIB REQUIRED)
find_package_wrapper(Freetype REQUIRED)

if(WITH_PYTHON)
  # No way to set py35, remove for now.
  # find_package(PythonLibs)

  # Use our own instead, since without py is such a rare case,
  # require this package
  # XXX Linking errors with debian static python :/
#       find_package_wrapper(PythonLibsUnix REQUIRED)
  find_package(PythonLibsUnix REQUIRED)
endif()

if(WITH_IMAGE_OPENEXR)
  find_package_wrapper(OpenEXR)  # our own module
  if(NOT OPENEXR_FOUND)
    set(WITH_IMAGE_OPENEXR OFF)
  endif()
endif()

if(WITH_IMAGE_OPENJPEG)
  find_package_wrapper(OpenJPEG)
  if(NOT OPENJPEG_FOUND)
    set(WITH_IMAGE_OPENJPEG OFF)
  endif()
endif()

if(WITH_IMAGE_TIFF)
  # XXX Linking errors with debian static tiff :/
#       find_package_wrapper(TIFF)
  find_package(TIFF)
  if(NOT TIFF_FOUND)
    set(WITH_IMAGE_TIFF OFF)
  endif()
endif()

if(WITH_OPENAL)
  find_package_wrapper(OpenAL)
  if(NOT OPENAL_FOUND)
    set(WITH_OPENAL OFF)
  endif()
endif()

if(WITH_SDL)
  if(WITH_SDL_DYNLOAD)
    set(SDL_INCLUDE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/extern/sdlew/include/SDL2")
    set(SDL_LIBRARY)
  else()
    find_package_wrapper(SDL2)
    if(SDL2_FOUND)
      # Use same names for both versions of SDL until we move to 2.x.
      set(SDL_INCLUDE_DIR "${SDL2_INCLUDE_DIR}")
      set(SDL_LIBRARY "${SDL2_LIBRARY}")
      set(SDL_FOUND "${SDL2_FOUND}")
    else()
      find_package_wrapper(SDL)
    endif()
    mark_as_advanced(
      SDL_INCLUDE_DIR
      SDL_LIBRARY
    )
    # unset(SDLMAIN_LIBRARY CACHE)
    if(NOT SDL_FOUND)
      set(WITH_SDL OFF)
    endif()
  endif()
endif()

# Codecs
if(WITH_CODEC_SNDFILE)
  find_package_wrapper(SndFile)
  if(NOT SNDFILE_FOUND)
    set(WITH_CODEC_SNDFILE OFF)
  endif()
endif()

if(WITH_CODEC_FFMPEG)
  if(EXISTS ${LIBDIR})
    # For precompiled lib directory, all ffmpeg dependencies are in the same folder
    file(GLOB ffmpeg_libs ${LIBDIR}/ffmpeg/lib/*.a ${LIBDIR}/sndfile/lib/*.a)
    set(FFMPEG ${LIBDIR}/ffmpeg CACHE PATH "FFMPEG Directory")
    set(FFMPEG_LIBRARIES ${ffmpeg_libs} ${ffmpeg_libs} CACHE STRING "FFMPEG Libraries")
  else()
    set(FFMPEG /usr CACHE PATH "FFMPEG Directory")
    set(FFMPEG_LIBRARIES avformat avcodec avutil avdevice swscale CACHE STRING "FFMPEG Libraries")
  endif()

  mark_as_advanced(FFMPEG)

  # lame, but until we have proper find module for ffmpeg
  set(FFMPEG_INCLUDE_DIRS ${FFMPEG}/include)
  if(EXISTS "${FFMPEG}/include/ffmpeg/")
    list(APPEND FFMPEG_INCLUDE_DIRS "${FFMPEG}/include/ffmpeg")
  endif()
  # end lameness

  mark_as_advanced(FFMPEG_LIBRARIES)
  set(FFMPEG_LIBPATH ${FFMPEG}/lib)
endif()

if(WITH_FFTW3)
  find_package_wrapper(Fftw3)
  if(NOT FFTW3_FOUND)
    set(WITH_FFTW3 OFF)
  endif()
endif()

if(WITH_OPENCOLLADA)
  find_package_wrapper(OpenCOLLADA)
  if(OPENCOLLADA_FOUND)
    if(WITH_STATIC_LIBS)
      # PCRE is bundled with OpenCollada without headers, so can't use
      # find_package reliably to detect it.
      set(PCRE_LIBRARIES ${LIBDIR}/opencollada/lib/libpcre.a)
    else()
      find_package_wrapper(PCRE)
    endif()
    find_package_wrapper(XML2)
  else()
    set(WITH_OPENCOLLADA OFF)
  endif()
endif()

if(WITH_MEM_JEMALLOC)
  find_package_wrapper(JeMalloc)
  if(NOT JEMALLOC_FOUND)
    set(WITH_MEM_JEMALLOC OFF)
  endif()
endif()

if(WITH_INPUT_NDOF)
  find_package_wrapper(Spacenav)
  if(SPACENAV_FOUND)
    # use generic names within blenders buildsystem.
    set(NDOF_INCLUDE_DIRS ${SPACENAV_INCLUDE_DIRS})
    set(NDOF_LIBRARIES ${SPACENAV_LIBRARIES})
  else()
    set(WITH_INPUT_NDOF OFF)
  endif()
endif()

if(WITH_CYCLES_OSL)
  set(CYCLES_OSL ${LIBDIR}/osl CACHE PATH "Path to OpenShadingLanguage installation")
  if(EXISTS ${CYCLES_OSL} AND NOT OSL_ROOT)
    set(OSL_ROOT ${CYCLES_OSL})
  endif()
  find_package_wrapper(OSL)
  if(OSL_FOUND)
    if(${OSL_LIBRARY_VERSION_MAJOR} EQUAL "1" AND ${OSL_LIBRARY_VERSION_MINOR} LESS "6")
      # Note: --whole-archive is needed to force loading of all symbols in liboslexec,
      # otherwise LLVM is missing the osl_allocate_closure_component function
      set(OSL_LIBRARIES
        ${OSL_OSLCOMP_LIBRARY}
        -Wl,--whole-archive ${OSL_OSLEXEC_LIBRARY}
        -Wl,--no-whole-archive ${OSL_OSLQUERY_LIBRARY}
      )
    endif()
  else()
    message(STATUS "OSL not found, disabling it from Cycles")
    set(WITH_CYCLES_OSL OFF)
  endif()
endif()

if(WITH_OPENVDB)
  find_package_wrapper(OpenVDB)
  find_package_wrapper(Blosc)

  if(NOT OPENVDB_FOUND)
    set(WITH_OPENVDB OFF)
    set(WITH_OPENVDB_BLOSC OFF)
    message(STATUS "OpenVDB not found, disabling it")
  elseif(NOT BLOSC_FOUND)
    set(WITH_OPENVDB_BLOSC OFF)
    message(STATUS "Blosc not found, disabling it for OpenVBD")
  endif()
endif()

if(WITH_NANOVDB)
  find_package_wrapper(NanoVDB)

  if(NOT NANOVDB_FOUND)
    set(WITH_NANOVDB OFF)
    message(STATUS "NanoVDB not found, disabling it")
  endif()
endif()

if(WITH_CPU_SIMD AND SUPPORT_NEON_BUILD)
  find_package_wrapper(sse2neon)
endif()

if(WITH_ALEMBIC)
  find_package_wrapper(Alembic)

  if(NOT ALEMBIC_FOUND)
    set(WITH_ALEMBIC OFF)
  endif()
endif()

if(WITH_USD)
  find_package_wrapper(USD)

  if(NOT USD_FOUND)
    set(WITH_USD OFF)
  endif()
endif()

if(WITH_BOOST)
  # uses in build instructions to override include and library variables
  if(NOT BOOST_CUSTOM)
    if(WITH_STATIC_LIBS)
      set(Boost_USE_STATIC_LIBS ON)
    endif()
    set(Boost_USE_MULTITHREADED ON)
    set(__boost_packages filesystem regex thread date_time)
    if(WITH_CYCLES_OSL)
      if(NOT (${OSL_LIBRARY_VERSION_MAJOR} EQUAL "1" AND ${OSL_LIBRARY_VERSION_MINOR} LESS "6"))
        list(APPEND __boost_packages wave)
      else()
      endif()
    endif()
    if(WITH_INTERNATIONAL)
      list(APPEND __boost_packages locale)
    endif()
    if(WITH_CYCLES_NETWORK)
      list(APPEND __boost_packages serialization)
    endif()
    if(WITH_OPENVDB)
      list(APPEND __boost_packages iostreams)
    endif()
    list(APPEND __boost_packages system)
    find_package(Boost 1.48 COMPONENTS ${__boost_packages})
    if(NOT Boost_FOUND)
      # try to find non-multithreaded if -mt not found, this flag
      # doesn't matter for us, it has nothing to do with thread
      # safety, but keep it to not disturb build setups
      set(Boost_USE_MULTITHREADED OFF)
      find_package(Boost 1.48 COMPONENTS ${__boost_packages})
    endif()
    unset(__boost_packages)
    if(Boost_USE_STATIC_LIBS AND WITH_BOOST_ICU)
      find_package(IcuLinux)
    endif()
    mark_as_advanced(Boost_DIR)  # why doesn't boost do this?
  endif()

  set(BOOST_INCLUDE_DIR ${Boost_INCLUDE_DIRS})
  set(BOOST_LIBRARIES ${Boost_LIBRARIES})
  set(BOOST_LIBPATH ${Boost_LIBRARY_DIRS})
  set(BOOST_DEFINITIONS "-DBOOST_ALL_NO_LIB")

  if(Boost_USE_STATIC_LIBS AND WITH_BOOST_ICU)
    find_package(IcuLinux)
    list(APPEND BOOST_LIBRARIES ${ICU_LIBRARIES})
  endif()
endif()

if(WITH_PUGIXML)
  find_package_wrapper(PugiXML)

  if(NOT PUGIXML_FOUND)
    set(WITH_PUGIXML OFF)
    message(STATUS "PugiXML not found, disabling WITH_PUGIXML")
  endif()
endif()

if(WITH_OPENIMAGEIO)
  find_package_wrapper(OpenImageIO)
  set(OPENIMAGEIO_LIBRARIES
    ${OPENIMAGEIO_LIBRARIES}
    ${PNG_LIBRARIES}
    ${JPEG_LIBRARIES}
    ${ZLIB_LIBRARIES}
    ${BOOST_LIBRARIES}
  )
  set(OPENIMAGEIO_LIBPATH)  # TODO, remove and reference the absolute path everywhere
  set(OPENIMAGEIO_DEFINITIONS "")

  if(WITH_IMAGE_TIFF)
    list(APPEND OPENIMAGEIO_LIBRARIES "${TIFF_LIBRARY}")
  endif()
  if(WITH_IMAGE_OPENEXR)
    list(APPEND OPENIMAGEIO_LIBRARIES "${OPENEXR_LIBRARIES}")
  endif()

  if(NOT OPENIMAGEIO_FOUND)
    set(WITH_OPENIMAGEIO OFF)
    message(STATUS "OpenImageIO not found, disabling WITH_CYCLES")
  endif()
endif()

if(WITH_OPENCOLORIO)
  find_package_wrapper(OpenColorIO 2.0.0)

  set(OPENCOLORIO_LIBRARIES ${OPENCOLORIO_LIBRARIES})
  set(OPENCOLORIO_LIBPATH)  # TODO, remove and reference the absolute path everywhere
  set(OPENCOLORIO_DEFINITIONS)

  if(NOT OPENCOLORIO_FOUND)
    set(WITH_OPENCOLORIO OFF)
    message(STATUS "OpenColorIO not found")
  endif()
endif()

if(WITH_CYCLES_EMBREE)
  find_package(Embree 3.8.0 REQUIRED)
endif()

if(WITH_OPENIMAGEDENOISE)
  find_package_wrapper(OpenImageDenoise)

  if(NOT OPENIMAGEDENOISE_FOUND)
    set(WITH_OPENIMAGEDENOISE OFF)
    message(STATUS "OpenImageDenoise not found")
  endif()
endif()

if(WITH_LLVM)
  if(EXISTS ${LIBDIR})
    set(LLVM_STATIC ON)
  endif()

  find_package_wrapper(LLVM)
  if(WITH_CLANG)
    find_package_wrapper(Clang)
  endif()
  # Symbol conflicts with same UTF library used by OpenCollada
  if(EXISTS ${LIBDIR})
    if(WITH_OPENCOLLADA AND (${LLVM_VERSION} VERSION_LESS "4.0.0"))
      list(REMOVE_ITEM OPENCOLLADA_LIBRARIES ${OPENCOLLADA_UTF_LIBRARY})
    endif()
  endif()

  if(NOT LLVM_FOUND)
    set(WITH_LLVM OFF)
    set(WITH_CLANG OFF)
    message(STATUS "LLVM not found")
  else()
    if(NOT CLANG_FOUND)
      set(WITH_CLANG OFF)
      message(STATUS "Clang not found")
    endif()
  endif()
endif()

if(WITH_OPENSUBDIV)
  find_package_wrapper(OpenSubdiv)

  set(OPENSUBDIV_LIBRARIES ${OPENSUBDIV_LIBRARIES})
  set(OPENSUBDIV_LIBPATH)  # TODO, remove and reference the absolute path everywhere

  if(NOT OPENSUBDIV_FOUND)
    set(WITH_OPENSUBDIV OFF)
    message(STATUS "OpenSubdiv not found")
  endif()
endif()

if(WITH_TBB)
  find_package_wrapper(TBB)
endif()

if(WITH_XR_OPENXR)
  find_package(XR_OpenXR_SDK)
  if(NOT XR_OPENXR_SDK_FOUND)
    message(WARNING "OpenXR-SDK not found, disabling WITH_XR_OPENXR")
    set(WITH_XR_OPENXR OFF)
  endif()
endif()

if(WITH_GMP)
  find_package_wrapper(GMP)
  if(NOT GMP_FOUND)
    message(WARNING "GMP not found, disabling WITH_GMP")
    set(WITH_GMP OFF)
  endif()
endif()

if(WITH_POTRACE)
  find_package_wrapper(Potrace)
  if(NOT POTRACE_FOUND)
    message(WARNING "potrace not found, disabling WITH_POTRACE")
    set(WITH_POTRACE OFF)
  endif()
endif()

if(WITH_HARU)
  find_package_wrapper(Haru)
  if(NOT HARU_FOUND)
    message(WARNING "Haru not found, disabling WITH_HARU")
    set(WITH_HARU OFF)
  endif()
endif()

if(EXISTS ${LIBDIR})
  without_system_libs_end()
endif()

# ----------------------------------------------------------------------------
# Build and Link Flags

# OpenSuse needs lutil, ArchLinux not, for now keep, can avoid by using --as-needed
if(HAIKU)
  list(APPEND PLATFORM_LINKLIBS -lnetwork)
else()
  list(APPEND PLATFORM_LINKLIBS -lutil -lc -lm)
endif()

find_package(Threads REQUIRED)
list(APPEND PLATFORM_LINKLIBS ${CMAKE_THREAD_LIBS_INIT})
# used by other platforms
set(PTHREADS_LIBRARIES ${CMAKE_THREAD_LIBS_INIT})

if(CMAKE_DL_LIBS)
  list(APPEND PLATFORM_LINKLIBS ${CMAKE_DL_LIBS})
endif()

if(CMAKE_SYSTEM_NAME MATCHES "Linux")
  if(NOT WITH_PYTHON_MODULE)
    # binreloc is linux only
    set(BINRELOC_INCLUDE_DIRS ${CMAKE_SOURCE_DIR}/extern/binreloc/include)
    set(WITH_BINRELOC ON)
  endif()
endif()

# lfs on glibc, all compilers should use
add_definitions(-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE64_SOURCE)

# ----------------------------------------------------------------------------
# System Libraries
#
# Keep last, so indirectly linked libraries don't override our own pre-compiled libs.

if(WITH_LZO AND WITH_SYSTEM_LZO)
  find_package_wrapper(LZO)
  if(NOT LZO_FOUND)
    message(FATAL_ERROR "Failed finding system LZO version!")
  endif()
endif()

if(WITH_SYSTEM_EIGEN3)
  find_package_wrapper(Eigen3)
  if(NOT EIGEN3_FOUND)
    message(FATAL_ERROR "Failed finding system Eigen3 version!")
  endif()
endif()

# Jack is intended to use the system library.
if(WITH_JACK)
  find_package_wrapper(Jack)
  if(NOT JACK_FOUND)
    set(WITH_JACK OFF)
  endif()
endif()

# Pulse is intended to use the system library.
if(WITH_PULSEAUDIO)
  find_package_wrapper(Pulse)
  if(NOT PULSE_FOUND)
    set(WITH_PULSEAUDIO OFF)
  endif()
endif()

# Audio IO
if(WITH_SYSTEM_AUDASPACE)
  find_package_wrapper(Audaspace)
  if(NOT AUDASPACE_FOUND OR NOT AUDASPACE_C_FOUND)
    message(FATAL_ERROR "Audaspace external library not found!")
  endif()
endif()

if(WITH_GHOST_WAYLAND)
  find_package(PkgConfig)
  pkg_check_modules(wayland-client REQUIRED wayland-client>=1.12)
  pkg_check_modules(wayland-egl REQUIRED wayland-egl)
  pkg_check_modules(wayland-scanner REQUIRED wayland-scanner)
  pkg_check_modules(xkbcommon REQUIRED xkbcommon)
  pkg_check_modules(wayland-cursor REQUIRED wayland-cursor)

  set(WITH_GL_EGL ON)

  if(WITH_GHOST_WAYLAND)
    list(APPEND PLATFORM_LINKLIBS
      ${wayland-client_LIBRARIES}
      ${wayland-egl_LIBRARIES}
      ${xkbcommon_LIBRARIES}
      ${wayland-cursor_LIBRARIES}
    )
  endif()
endif()

if(WITH_GHOST_X11)
  find_package(X11 REQUIRED)

  find_path(X11_XF86keysym_INCLUDE_PATH X11/XF86keysym.h ${X11_INC_SEARCH_PATH})
  mark_as_advanced(X11_XF86keysym_INCLUDE_PATH)

  list(APPEND PLATFORM_LINKLIBS ${X11_X11_LIB})

  if(WITH_X11_XINPUT)
    if(X11_Xinput_LIB)
      list(APPEND PLATFORM_LINKLIBS ${X11_Xinput_LIB})
    else()
      message(FATAL_ERROR "LibXi not found. Disable WITH_X11_XINPUT if you
      want to build without tablet support")
    endif()
  endif()

  if(WITH_X11_XF86VMODE)
    # XXX, why doesn't cmake make this available?
    find_library(X11_Xxf86vmode_LIB Xxf86vm   ${X11_LIB_SEARCH_PATH})
    mark_as_advanced(X11_Xxf86vmode_LIB)
    if(X11_Xxf86vmode_LIB)
      list(APPEND PLATFORM_LINKLIBS ${X11_Xxf86vmode_LIB})
    else()
      message(FATAL_ERROR "libXxf86vm not found. Disable WITH_X11_XF86VMODE if you
      want to build without")
    endif()
  endif()

  if(WITH_X11_XFIXES)
    if(X11_Xfixes_LIB)
      list(APPEND PLATFORM_LINKLIBS ${X11_Xfixes_LIB})
    else()
      message(FATAL_ERROR "libXfixes not found. Disable WITH_X11_XFIXES if you
      want to build without")
    endif()
  endif()

  if(WITH_X11_ALPHA)
    find_library(X11_Xrender_LIB Xrender  ${X11_LIB_SEARCH_PATH})
    mark_as_advanced(X11_Xrender_LIB)
    if(X11_Xrender_LIB)
      list(APPEND PLATFORM_LINKLIBS ${X11_Xrender_LIB})
    else()
      message(FATAL_ERROR "libXrender not found. Disable WITH_X11_ALPHA if you
      want to build without")
    endif()
  endif()

endif()

# ----------------------------------------------------------------------------
# Compilers

# GNU Compiler
if(CMAKE_COMPILER_IS_GNUCC)
  # ffp-contract=off:
  # Automatically turned on when building with "-march=native". This is
  # explicitly turned off here as it will make floating point math give a bit
  # different results. This will lead to automated test failures. So disable
  # this until we support it. Seems to default to off in clang and the intel
  # compiler.
  set(PLATFORM_CFLAGS "-pipe -fPIC -funsigned-char -fno-strict-aliasing -ffp-contract=off")

  # `maybe-uninitialized` is unreliable in release builds, but fine in debug builds.
  set(GCC_EXTRA_FLAGS_RELEASE "-Wno-maybe-uninitialized")
  set(CMAKE_C_FLAGS_RELEASE          "${GCC_EXTRA_FLAGS_RELEASE} ${CMAKE_C_FLAGS_RELEASE}")
  set(CMAKE_C_FLAGS_RELWITHDEBINFO   "${GCC_EXTRA_FLAGS_RELEASE} ${CMAKE_C_FLAGS_RELWITHDEBINFO}")
  set(CMAKE_CXX_FLAGS_RELEASE        "${GCC_EXTRA_FLAGS_RELEASE} ${CMAKE_CXX_FLAGS_RELEASE}")
  string(PREPEND CMAKE_CXX_FLAGS_RELWITHDEBINFO "${GCC_EXTRA_FLAGS_RELEASE} ")
  unset(GCC_EXTRA_FLAGS_RELEASE)

  if(WITH_LINKER_GOLD)
    execute_process(
      COMMAND ${CMAKE_C_COMPILER} -fuse-ld=gold -Wl,--version
      ERROR_QUIET OUTPUT_VARIABLE LD_VERSION)
    if("${LD_VERSION}" MATCHES "GNU gold")
      string(APPEND CMAKE_C_FLAGS " -fuse-ld=gold")
      string(APPEND CMAKE_CXX_FLAGS " -fuse-ld=gold")
    else()
      message(STATUS "GNU gold linker isn't available, using the default system linker.")
    endif()
    unset(LD_VERSION)
  endif()

  if(WITH_LINKER_LLD)
    execute_process(
      COMMAND ${CMAKE_C_COMPILER} -fuse-ld=lld -Wl,--version
      ERROR_QUIET OUTPUT_VARIABLE LD_VERSION)
    if("${LD_VERSION}" MATCHES "LLD")
      string(APPEND CMAKE_C_FLAGS " -fuse-ld=lld")
      string(APPEND CMAKE_CXX_FLAGS " -fuse-ld=lld")
    else()
      message(STATUS "LLD linker isn't available, using the default system linker.")
    endif()
    unset(LD_VERSION)
  endif()

# CLang is the same as GCC for now.
elseif(CMAKE_C_COMPILER_ID MATCHES "Clang")
  set(PLATFORM_CFLAGS "-pipe -fPIC -funsigned-char -fno-strict-aliasing")
# Intel C++ Compiler
elseif(CMAKE_C_COMPILER_ID MATCHES "Intel")
  # think these next two are broken
  find_program(XIAR xiar)
  if(XIAR)
    set(CMAKE_AR "${XIAR}")
  endif()
  mark_as_advanced(XIAR)

  find_program(XILD xild)
  if(XILD)
    set(CMAKE_LINKER "${XILD}")
  endif()
  mark_as_advanced(XILD)

  string(APPEND CMAKE_C_FLAGS " -fp-model precise -prec_div -parallel")
  string(APPEND CMAKE_CXX_FLAGS " -fp-model precise -prec_div -parallel")

  # string(APPEND PLATFORM_CFLAGS " -diag-enable sc3")
  set(PLATFORM_CFLAGS "-pipe -fPIC -funsigned-char -fno-strict-aliasing")
  string(APPEND PLATFORM_LINKFLAGS " -static-intel")
endif()

# Avoid conflicts with Mesa llvmpipe, Luxrender, and other plug-ins that may
# use the same libraries as Blender with a different version or build options.
set(PLATFORM_LINKFLAGS
  "${PLATFORM_LINKFLAGS} -Wl,--version-script='${CMAKE_SOURCE_DIR}/source/creator/blender.map'"
)

# Don't use position independent executable for portable install since file
# browsers can't properly detect blender as an executable then. Still enabled
# for non-portable installs as typically used by Linux distributions.
if(WITH_INSTALL_PORTABLE)
  string(APPEND CMAKE_EXE_LINKER_FLAGS " -no-pie")
endif()

if(WITH_COMPILER_CCACHE)
  find_program(CCACHE_PROGRAM ccache)
  if(CCACHE_PROGRAM)
    # Makefiles and ninja
    set(CMAKE_C_COMPILER_LAUNCHER   "${CCACHE_PROGRAM}" CACHE STRING "" FORCE)
    set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}" CACHE STRING "" FORCE)
  else()
    message(WARNING "Ccache NOT found, disabling WITH_COMPILER_CCACHE")
    set(WITH_COMPILER_CCACHE OFF)
  endif()
endif()