MegEngine/toolchains/ios.toolchain.cmake

# This file is part of the ios-cmake project. It was retrieved from
# https://github.com/cristeab/ios-cmake.git, which is a fork of
# https://code.google.com/p/ios-cmake/. Which in turn is based off of the
# Platform/Darwin.cmake and Platform/UnixPaths.cmake files which are included with CMake
# 2.8.4
#
# The ios-cmake project is licensed under the new BSD license.
#
# Copyright (c) 2014, Bogdan Cristea and LTE Engineering Software, Kitware, Inc.,
# Insight Software Consortium.  All rights reserved. Redistribution and use in source
# and binary forms, with or without modification, are permitted provided that the
# following conditions are met: 1. Redistributions of source code must retain the above
# copyright notice, this list of conditions and the following disclaimer.
#
# 1. Redistributions in binary form must reproduce the above copyright notice, this list
#   of conditions and the following disclaimer in the documentation and/or other
#   materials provided with the distribution.
#
# 1. Neither the name of the copyright holder nor the names of its contributors may be
#   used to endorse or promote products derived from this software without specific
#   prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
# SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
# WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
# DAMAGE.
#
# This file is based off of the Platform/Darwin.cmake and Platform/UnixPaths.cmake files
# which are included with CMake 2.8.4 It has been altered for iOS development.
#
# Updated by Alex Stewart (alexs.mac@gmail.com)
#
# *****************************************************************************
# Now maintained by Alexander Widerberg (widerbergaren [at] gmail.com) under the
# BSD-3-Clause license https://github.com/leetal/ios-cmake
# *****************************************************************************
#
# INFORMATION / HELP
#
# The following variables control the behaviour of this toolchain:
#
# IOS_PLATFORM: OS (default) or SIMULATOR or SIMULATOR64 or TVOS or SIMULATOR_TVOS or
# WATCHOS or SIMULATOR_WATCHOS OS = Build for iPhoneOS. OS64 = Build for arm64 arm64e
# iPhoneOS. SIMULATOR = Build for x86 i386 iPhone Simulator. SIMULATOR64 = Build for
# x86_64 iPhone Simulator. TVOS = Build for AppleTVOS. SIMULATOR_TVOS = Build for x86_64
# AppleTV Simulator. WATCHOS = Build for armv7k arm64_32 for WatchOS. SIMULATOR_WATCHOS
# = Build for x86_64 for Watch Simulator. CMAKE_OSX_SYSROOT: Path to the iOS SDK to use.
# By default this is automatically determined from IOS_PLATFORM and xcodebuild, but can
# also be manually specified (although this should not be required).
# CMAKE_IOS_DEVELOPER_ROOT: Path to the Developer directory for the iOS platform being
# compiled for.  By default this is automatically determined from CMAKE_OSX_SYSROOT, but
# can also be manually specified (although this should not be required). ENABLE_BITCODE:
# (1|0) Enables or disables bitcode support. Default 1 (true) ENABLE_ARC: (1|0) Enables
# or disables ARC support. Default 1 (true, ARC enabled by default) ENABLE_VISIBILITY:
# (1|0) Enables or disables symbol visibility support. Default 0 (false, visibility
# hidden by default) IOS_ARCH: (armv7 armv7s armv7k arm64 arm64e arm64_32 i386 x86_64)
# If specified, will override the default architectures for the given IOS_PLATFORM OS =
# armv7 armv7s arm64 arm64e (if applicable) OS64 = arm64 arm64e (if applicable)
# SIMULATOR = i386 x86_64 SIMULATOR64 = x86_64 TVOS = arm64 SIMULATOR_TVOS = x86_64
# (i386 has since long been deprecated) WATCHOS = armv7k arm64_32 (if applicable)
# SIMULATOR_WATCHOS = x86_64 (i386 has since long been deprecated)
#
# This toolchain defines the following variables for use externally:
#
# XCODE_VERSION: Version number (not including Build version) of Xcode detected.
# IOS_SDK_VERSION: Version of iOS SDK being used. CMAKE_OSX_ARCHITECTURES: Architectures
# being compiled for (generated from IOS_PLATFORM).
#
# This toolchain defines the following macros for use externally:
#
# set_xcode_property (TARGET XCODE_PROPERTY XCODE_VALUE XCODE_VARIANT) A convenience
# macro for setting xcode specific properties on targets. Available variants are: All,
# Release, RelWithDebInfo, Debug, MinSizeRel example: set_xcode_property (myioslib
# IPHONEOS_DEPLOYMENT_TARGET "3.1" "all").
#
# find_host_package (PROGRAM ARGS) A macro used to find executable programs on the host
# system, not within the iOS environment.  Thanks to the android-cmake project for
# providing the command.

# Fix for PThread library not in path
set(CMAKE_THREAD_LIBS_INIT "-lpthread")
set(CMAKE_HAVE_THREADS_LIBRARY 1)
set(CMAKE_USE_WIN32_THREADS_INIT 0)
set(CMAKE_USE_PTHREADS_INIT 1)

# Get the Xcode version being used.
execute_process(
  COMMAND xcodebuild -version
  OUTPUT_VARIABLE XCODE_VERSION
  ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
string(REGEX MATCH "Xcode [0-9\\.]+" XCODE_VERSION "${XCODE_VERSION}")
string(REGEX REPLACE "Xcode ([0-9\\.]+)" "\\1" XCODE_VERSION "${XCODE_VERSION}")
message(STATUS "Building with Xcode version: ${XCODE_VERSION}")
# Default to building for iPhoneOS if not specified otherwise, and we cannot determine
# the platform from the CMAKE_OSX_ARCHITECTURES variable. The use of
# CMAKE_OSX_ARCHITECTURES is such that try_compile() projects can correctly determine
# the value of IOS_PLATFORM from the root project, as CMAKE_OSX_ARCHITECTURES is
# propagated to them by CMake.
if(NOT DEFINED IOS_PLATFORM)
  if(CMAKE_OSX_ARCHITECTURES)
    if(CMAKE_OSX_ARCHITECTURES MATCHES ".*arm.*")
      set(IOS_PLATFORM "OS")
    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "i386")
      set(IOS_PLATFORM "SIMULATOR")
    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "x86_64")
      set(IOS_PLATFORM "SIMULATOR64")
    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "armv7k")
      set(IOS_PLATFORM "WATCHOS")
    endif()
  endif()
  if(NOT IOS_PLATFORM)
    set(IOS_PLATFORM "OS")
  endif()
endif()
set(IOS_PLATFORM
    ${IOS_PLATFORM}
    CACHE STRING "Type of iOS platform for which to build.")
# Determine the platform name and architectures for use in xcodebuild commands from the
# specified IOS_PLATFORM name.
if(IOS_PLATFORM STREQUAL "OS")
  set(XCODE_IOS_PLATFORM iphoneos)
  if(NOT IOS_ARCH)
    if(XCODE_VERSION VERSION_GREATER 10.0)
      set(IOS_ARCH armv7 armv7s arm64 arm64e)
    else()
      set(IOS_ARCH armv7 armv7s arm64)
    endif()
  endif()
elseif(IOS_PLATFORM STREQUAL "OS64")
  set(XCODE_IOS_PLATFORM iphoneos)
  if(NOT IOS_ARCH)
    if(XCODE_VERSION VERSION_GREATER 10.0)
      set(IOS_ARCH arm64 arm64e)
    else()
      set(IOS_ARCH arm64)
    endif()
  endif()
elseif(IOS_PLATFORM STREQUAL "SIMULATOR")
  set(XCODE_IOS_PLATFORM iphonesimulator)
  if(NOT IOS_ARCH)
    set(IOS_ARCH i386 x86_64)
  endif()
elseif(IOS_PLATFORM STREQUAL "SIMULATOR64")
  set(XCODE_IOS_PLATFORM iphonesimulator)
  if(NOT IOS_ARCH)
    set(IOS_ARCH x86_64)
  endif()
elseif(IOS_PLATFORM STREQUAL "TVOS")
  set(XCODE_IOS_PLATFORM appletvos)
  if(NOT IOS_ARCH)
    set(IOS_ARCH arm64)
  endif()
elseif(IOS_PLATFORM STREQUAL "SIMULATOR_TVOS")
  set(XCODE_IOS_PLATFORM appletvsimulator)
  if(NOT IOS_ARCH)
    set(IOS_ARCH x86_64)
  endif()
elseif(IOS_PLATFORM STREQUAL "WATCHOS")
  set(XCODE_IOS_PLATFORM watchos)
  if(NOT IOS_ARCH)
    if(XCODE_VERSION VERSION_GREATER 10.0)
      set(IOS_ARCH armv7k arm64_32)
    else()
      set(IOS_ARCH armv7k)
    endif()
  endif()
elseif(IOS_PLATFORM STREQUAL "SIMULATOR_WATCHOS")
  set(XCODE_IOS_PLATFORM watchsimulator)
  if(NOT IOS_ARCH)
    set(IOS_ARCH x86_64)
  endif()
else()
  message(FATAL_ERROR "Invalid IOS_PLATFORM: ${IOS_PLATFORM}")
endif()
message(STATUS "Configuring iOS build for platform: ${IOS_PLATFORM}, "
               "architecture(s): ${IOS_ARCH}")
# If user did not specify the SDK root to use, then query xcodebuild for it.
execute_process(
  COMMAND xcodebuild -version -sdk ${XCODE_IOS_PLATFORM} Path
  OUTPUT_VARIABLE CMAKE_OSX_SYSROOT_INT
  OUTPUT_QUIET ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
# If user did not specify the SDK root to use, then query xcodebuild for it.
if(NOT DEFINED CMAKE_OSX_SYSROOT OR (NOT CMAKE_OSX_SYSROOT STREQUAL
                                     CMAKE_OSX_SYSROOT_INT))
  execute_process(
    COMMAND xcodebuild -version -sdk ${XCODE_IOS_PLATFORM} Path
    OUTPUT_VARIABLE CMAKE_OSX_SYSROOT
    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
endif()
if(NOT EXISTS ${CMAKE_OSX_SYSROOT})
  message(
    SEND_ERROR "Please make sure that Xcode is installed and that the toolchain"
               "is pointing to the correct path. Please run:"
               "sudo xcode-select -s /Applications/Xcode.app/Contents/Developer"
               "and see if that fixes the problem for you.")
  message(FATAL_ERROR "Invalid CMAKE_OSX_SYSROOT: ${CMAKE_OSX_SYSROOT} "
                      "does not exist.")
elseif(DEFINED CMAKE_OSX_SYSROOT)
  message(
    STATUS
      "Using manually set SDK path: ${CMAKE_OSX_SYSROOT} for platform: ${IOS_PLATFORM}")
else()
  message(STATUS "Using SDK: ${CMAKE_OSX_SYSROOT} for platform: ${IOS_PLATFORM}")
endif()
# Specify minimum version of deployment target.
if(NOT DEFINED IOS_DEPLOYMENT_TARGET)
  if(IOS_PLATFORM STREQUAL "WATCHOS" OR IOS_PLATFORM STREQUAL "SIMULATOR_WATCHOS")
    # Unless specified, SDK version 2.0 is used by default as minimum target version
    # (watchOS).
    set(IOS_DEPLOYMENT_TARGET
        "2.0"
        CACHE STRING "Minimum iOS version to build for.")
  else()
    # Unless specified, SDK version 10.0 is used by default as minimum target version
    # (iOS, tvOS).
    set(IOS_DEPLOYMENT_TARGET
        "10.0"
        CACHE STRING "Minimum iOS version to build for.")
  endif()
  message(
    STATUS "Using the default min-version since IOS_DEPLOYMENT_TARGET not provided!")
endif()
# Use bitcode or not
if(NOT DEFINED ENABLE_BITCODE AND NOT IOS_ARCH MATCHES "((^|, )(i386|x86_64))+")
  # Unless specified, enable bitcode support by default
  set(ENABLE_BITCODE
      TRUE
      CACHE BOOL "Whether or not to enable bitcode")
  message(STATUS "Enabling bitcode support by default. ENABLE_BITCODE not provided!")
endif()
if(NOT DEFINED ENABLE_BITCODE)
  message(
    STATUS
      "Disabling bitcode support by default on simulators. ENABLE_BITCODE not provided for override!"
  )
endif()
# Use ARC or not
if(NOT DEFINED ENABLE_ARC)
  # Unless specified, enable ARC support by default
  set(ENABLE_ARC
      TRUE
      CACHE BOOL "Whether or not to enable ARC")
  message(STATUS "Enabling ARC support by default. ENABLE_ARC not provided!")
endif()
# Use hidden visibility or not
if(NOT DEFINED ENABLE_VISIBILITY)
  # Unless specified, disable symbols visibility by default
  set(ENABLE_VISIBILITY
      FALSE
      CACHE BOOL "Whether or not to hide symbols (-fvisibility=hidden)")
  message(
    STATUS "Hiding symbols visibility by default. ENABLE_VISIBILITY not provided!")
endif()
# Get the SDK version information.
execute_process(
  COMMAND xcodebuild -sdk ${CMAKE_OSX_SYSROOT} -version SDKVersion
  OUTPUT_VARIABLE IOS_SDK_VERSION
  ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
# Find the Developer root for the specific iOS platform being compiled for from
# CMAKE_OSX_SYSROOT.  Should be ../../ from SDK specified in CMAKE_OSX_SYSROOT.  There
# does not appear to be a direct way to obtain this information from xcrun or
# xcodebuild.
if(NOT CMAKE_IOS_DEVELOPER_ROOT)
  get_filename_component(IOS_PLATFORM_SDK_DIR ${CMAKE_OSX_SYSROOT} PATH)
  get_filename_component(CMAKE_IOS_DEVELOPER_ROOT ${IOS_PLATFORM_SDK_DIR} PATH)
endif()
if(NOT EXISTS ${CMAKE_IOS_DEVELOPER_ROOT})
  message(FATAL_ERROR "Invalid CMAKE_IOS_DEVELOPER_ROOT: "
                      "${CMAKE_IOS_DEVELOPER_ROOT} does not exist.")
endif()
# Find the C & C++ compilers for the specified SDK.
if(NOT CMAKE_C_COMPILER)
  execute_process(
    COMMAND xcrun -sdk ${CMAKE_OSX_SYSROOT} -find clang
    OUTPUT_VARIABLE CMAKE_C_COMPILER
    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
  message(STATUS "Using C compiler: ${CMAKE_C_COMPILER}")
endif()
if(NOT CMAKE_CXX_COMPILER)
  execute_process(
    COMMAND xcrun -sdk ${CMAKE_OSX_SYSROOT} -find clang++
    OUTPUT_VARIABLE CMAKE_CXX_COMPILER
    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
  message(STATUS "Using CXX compiler: ${CMAKE_CXX_COMPILER}")
endif()
# Find (Apple's) libtool.
execute_process(
  COMMAND xcrun -sdk ${CMAKE_OSX_SYSROOT} -find libtool
  OUTPUT_VARIABLE IOS_LIBTOOL
  ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
message(STATUS "Using libtool: ${IOS_LIBTOOL}")
# Configure libtool to be used instead of ar + ranlib to build static libraries. This is
# required on Xcode 7+, but should also work on previous versions of Xcode.
set(CMAKE_C_CREATE_STATIC_LIBRARY
    "${IOS_LIBTOOL} -static -o <TARGET> <LINK_FLAGS> <OBJECTS> ")
set(CMAKE_CXX_CREATE_STATIC_LIBRARY
    "${IOS_LIBTOOL} -static -o <TARGET> <LINK_FLAGS> <OBJECTS> ")
# Get the version of Darwin (OS X) of the host.
execute_process(
  COMMAND uname -r
  OUTPUT_VARIABLE CMAKE_HOST_SYSTEM_VERSION
  ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
# Standard settings.
set(CMAKE_SYSTEM_NAME
    Darwin
    CACHE INTERNAL "")
set(CMAKE_SYSTEM_VERSION
    ${IOS_SDK_VERSION}
    CACHE INTERNAL "")
set(UNIX
    TRUE
    CACHE BOOL "")
set(APPLE
    TRUE
    CACHE BOOL "")
set(IOS
    TRUE
    CACHE BOOL "")
set(CMAKE_AR
    ar
    CACHE FILEPATH "" FORCE)
set(CMAKE_RANLIB
    ranlib
    CACHE FILEPATH "" FORCE)
# Force unset of OS X-specific deployment target (otherwise autopopulated), required as
# of cmake 2.8.10.
set(CMAKE_OSX_DEPLOYMENT_TARGET
    ""
    CACHE STRING "Must be empty for iOS builds." FORCE)
# Set the architectures for which to build.
set(CMAKE_OSX_ARCHITECTURES
    ${IOS_ARCH}
    CACHE STRING "Build architecture for iOS")
# Change the type of target generated for try_compile() so it'll work when
# cross-compiling
set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
# All iOS/Darwin specific settings - some may be redundant.
set(CMAKE_SHARED_LIBRARY_PREFIX "lib")
set(CMAKE_SHARED_LIBRARY_SUFFIX ".dylib")
set(CMAKE_SHARED_MODULE_PREFIX "lib")
set(CMAKE_SHARED_MODULE_SUFFIX ".so")
set(CMAKE_C_COMPILER_ABI ELF)
set(CMAKE_CXX_COMPILER_ABI ELF)
set(CMAKE_C_HAS_ISYSROOT 1)
set(CMAKE_CXX_HAS_ISYSROOT 1)
set(CMAKE_MODULE_EXISTS 1)
set(CMAKE_DL_LIBS "")
set(CMAKE_C_OSX_COMPATIBILITY_VERSION_FLAG "-compatibility_version ")
set(CMAKE_C_OSX_CURRENT_VERSION_FLAG "-current_version ")
set(CMAKE_CXX_OSX_COMPATIBILITY_VERSION_FLAG
    "${CMAKE_C_OSX_COMPATIBILITY_VERSION_FLAG}")
set(CMAKE_CXX_OSX_CURRENT_VERSION_FLAG "${CMAKE_C_OSX_CURRENT_VERSION_FLAG}")

if(IOS_ARCH MATCHES "((^|, )(arm64|arm64e|x86_64))+")
  set(CMAKE_C_SIZEOF_DATA_PTR 8)
  set(CMAKE_CXX_SIZEOF_DATA_PTR 8)
  message(STATUS "Using a data_ptr size of 8")
else()
  set(CMAKE_C_SIZEOF_DATA_PTR 4)
  set(CMAKE_CXX_SIZEOF_DATA_PTR 4)
  message(STATUS "Using a data_ptr size of 4")
endif()

message(STATUS "Building for minimum iOS version: ${IOS_DEPLOYMENT_TARGET}"
               " (SDK version: ${IOS_SDK_VERSION})")
# Note that only Xcode 7+ supports the newer more specific:
# -m${XCODE_IOS_PLATFORM}-version-min flags, older versions of Xcode use:
# -m(ios/ios-simulator)-version-min instead.
if(IOS_PLATFORM STREQUAL "OS" OR IOS_PLATFORM STREQUAL "OS64")
  if(XCODE_VERSION VERSION_LESS 7.0)
    set(XCODE_IOS_PLATFORM_VERSION_FLAGS "-mios-version-min=${IOS_DEPLOYMENT_TARGET}")
  else()
    # Xcode 7.0+ uses flags we can build directly from XCODE_IOS_PLATFORM.
    set(XCODE_IOS_PLATFORM_VERSION_FLAGS
        "-m${XCODE_IOS_PLATFORM}-version-min=${IOS_DEPLOYMENT_TARGET}")
  endif()
elseif(IOS_PLATFORM STREQUAL "TVOS")
  set(XCODE_IOS_PLATFORM_VERSION_FLAGS "-mtvos-version-min=${IOS_DEPLOYMENT_TARGET}")
elseif(IOS_PLATFORM STREQUAL "SIMULATOR_TVOS")
  set(XCODE_IOS_PLATFORM_VERSION_FLAGS
      "-mtvos-simulator-version-min=${IOS_DEPLOYMENT_TARGET}")
elseif(IOS_PLATFORM STREQUAL "WATCHOS")
  set(XCODE_IOS_PLATFORM_VERSION_FLAGS "-mwatchos-version-min=${IOS_DEPLOYMENT_TARGET}")
elseif(IOS_PLATFORM STREQUAL "SIMULATOR_WATCHOS")
  set(XCODE_IOS_PLATFORM_VERSION_FLAGS
      "-mwatchos-simulator-version-min=${IOS_DEPLOYMENT_TARGET}")
else()
  # SIMULATOR or SIMULATOR64 both use -mios-simulator-version-min.
  set(XCODE_IOS_PLATFORM_VERSION_FLAGS
      "-mios-simulator-version-min=${IOS_DEPLOYMENT_TARGET}")
endif()
message(STATUS "Version flags set to: ${XCODE_IOS_PLATFORM_VERSION_FLAGS}")

if(ENABLE_BITCODE)
  set(BITCODE "-fembed-bitcode")
  set(HEADER_PAD "")
  message(STATUS "Enabling bitcode support.")
else()
  set(BITCODE "")
  set(HEADER_PAD "-headerpad_max_install_names")
  message(STATUS "Disabling bitcode support.")
endif()

if(ENABLE_ARC)
  set(FOBJC_ARC "-fobjc-arc")
  message(STATUS "Enabling ARC support.")
else()
  set(FOBJC_ARC "-fno-objc-arc")
  message(STATUS "Disabling ARC support.")
endif()

if(NOT ENABLE_VISIBILITY)
  set(VISIBILITY "-fvisibility=hidden")
  message(STATUS "Hiding symbols (-fvisibility=hidden).")
else()
  set(VISIBILITY "")
endif()

set(CMAKE_C_FLAGS
    "${XCODE_IOS_PLATFORM_VERSION_FLAGS} ${BITCODE} -fobjc-abi-version=2 ${FOBJC_ARC} ${CMAKE_C_FLAGS}"
)
# Hidden visibilty is required for C++ on iOS.
set(CMAKE_CXX_FLAGS
    "${XCODE_IOS_PLATFORM_VERSION_FLAGS} ${BITCODE} ${VISIBILITY} -fvisibility-inlines-hidden -fobjc-abi-version=2 ${FOBJC_ARC} ${CMAKE_CXX_FLAGS}"
)
set(CMAKE_CXX_FLAGS_MINSIZEREL
    "${CMAKE_CXX_FLAGS} -DNDEBUG -Os -ffast-math ${BITCODE} ${CMAKE_CXX_FLAGS_MINSIZEREL}"
)
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO
    "${CMAKE_CXX_FLAGS} -DNDEBUG -O2 -g -ffast-math ${BITCODE} ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}"
)
set(CMAKE_CXX_FLAGS_RELEASE
    "${CMAKE_CXX_FLAGS} -DNDEBUG -O3 -ffast-math ${BITCODE} ${CMAKE_CXX_FLAGS_RELEASE}")
set(CMAKE_C_LINK_FLAGS
    "${XCODE_IOS_PLATFORM_VERSION_FLAGS} -Wl,-search_paths_first ${CMAKE_C_LINK_FLAGS}")
set(CMAKE_CXX_LINK_FLAGS
    "${XCODE_IOS_PLATFORM_VERSION_FLAGS}  -Wl,-search_paths_first ${CMAKE_CXX_LINK_FLAGS}"
)

# In order to ensure that the updated compiler flags are used in try_compile() tests, we
# have to forcibly set them in the CMake cache, not merely set them in the local scope.
list(
  APPEND
  VARS_TO_FORCE_IN_CACHE
  CMAKE_C_FLAGS
  CMAKE_CXX_FLAGS
  CMAKE_CXX_FLAGS_RELWITHDEBINFO
  CMAKE_CXX_FLAGS_MINSIZEREL
  CMAKE_CXX_FLAGS_RELEASE
  CMAKE_C_LINK_FLAGS
  CMAKE_CXX_LINK_FLAGS)
foreach(VAR_TO_FORCE ${VARS_TO_FORCE_IN_CACHE})
  set(${VAR_TO_FORCE}
      "${${VAR_TO_FORCE}}"
      CACHE STRING "")
endforeach()

set(CMAKE_PLATFORM_HAS_INSTALLNAME 1)
set(CMAKE_SHARED_LINKER_FLAGS
    "-rpath @executable_path/Frameworks -rpath @loader_path/Frameworks")
set(CMAKE_SHARED_LIBRARY_CREATE_C_FLAGS "-dynamiclib ${HEADER_PAD}")
set(CMAKE_SHARED_MODULE_CREATE_C_FLAGS "-bundle ${HEADER_PAD}")
set(CMAKE_SHARED_MODULE_LOADER_C_FLAG "-Wl,-bundle_loader,")
set(CMAKE_SHARED_MODULE_LOADER_CXX_FLAG "-Wl,-bundle_loader,")
set(CMAKE_FIND_LIBRARY_SUFFIXES ".dylib" ".so" ".a")

# Hack: if a new cmake (which uses CMAKE_INSTALL_NAME_TOOL) runs on an old build tree
# (where install_name_tool was hardcoded) and where CMAKE_INSTALL_NAME_TOOL isn't in the
# cache and still cmake didn't fail in CMakeFindBinUtils.cmake (because it isn't rerun)
# hardcode CMAKE_INSTALL_NAME_TOOL here to install_name_tool, so it behaves as it did
# before, Alex.
if(NOT DEFINED CMAKE_INSTALL_NAME_TOOL)
  find_program(CMAKE_INSTALL_NAME_TOOL install_name_tool)
endif(NOT DEFINED CMAKE_INSTALL_NAME_TOOL)

# Set the find root to the iOS developer roots and to user defined paths.
set(CMAKE_FIND_ROOT_PATH
    ${CMAKE_IOS_DEVELOPER_ROOT} ${CMAKE_OSX_SYSROOT} ${CMAKE_PREFIX_PATH}
    CACHE STRING "iOS find search path root" FORCE)
# Default to searching for frameworks first.
set(CMAKE_FIND_FRAMEWORK FIRST)
# Set up the default search directories for frameworks.
set(CMAKE_SYSTEM_FRAMEWORK_PATH
    ${CMAKE_OSX_SYSROOT}/System/Library/Frameworks
    ${CMAKE_OSX_SYSROOT}/System/Library/PrivateFrameworks
    ${CMAKE_OSX_SYSROOT}/Developer/Library/Frameworks)
# Only search the specified iOS SDK, not the remainder of the host filesystem.
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
# This little macro lets you set any XCode specific property.
macro(set_xcode_property TARGET XCODE_PROPERTY XCODE_VALUE XCODE_RELVERSION)
  set(XCODE_RELVERSION_I "${XCODE_RELVERSION}")
  if(XCODE_RELVERSION_I STREQUAL "All")
    set_property(TARGET ${TARGET} PROPERTY XCODE_ATTRIBUTE_${XCODE_PROPERTY}
                                           "${XCODE_VALUE}")
  else()
    set_property(
      TARGET ${TARGET}
      PROPERTY XCODE_ATTRIBUTE_${XCODE_PROPERTY}[variant=${XCODE_RELVERSION_I}]
               "${XCODE_VALUE}")
  endif()
endmacro(set_xcode_property)
# This macro lets you find executable programs on the host system.
macro(find_host_package)
  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY NEVER)
  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE NEVER)
  set(IOS FALSE)
  find_package(${ARGN})
  set(IOS TRUE)
  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM ONLY)
  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
endmacro(find_host_package)