Add ios build for travis (#452)

* Add ios build for travis

* fix cmake command and set osx_image: xcode11

* print cmake version

* print cmake version before config

* [iOS] By default use iphoneos for sysroot

* Use ios.toolchain.cmake to build ios

* By default, don't require gnu extension

* Update CMakeLists.txt

Co-authored-by: deal <[email protected]>

2 files changed, 744 insertions, 1 deletions

diff --git a/.travis.yml b/.travis.yml
index 857e9784..41318268 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,6 +10,10 @@ matrix:
     - os: freebsd
       compiler: clang
     - os: osx
+    - os: osx
+      osx_image: xcode11
+      env:
+        - BUILD_IOS=true
 sudo: required
 install:
   - >
@@ -63,6 +67,7 @@ install:
         $NULL
     fi
 script:
+  - cmake --version
   - >
     if [[ "${TRAVIS_OS_NAME}" == "linux" && -z "${BUILD_ANDROID}" ]]; then
       cmake \
@@ -99,10 +104,23 @@ script:
         .
     fi
   - >
-    if [[ "${TRAVIS_OS_NAME}" == "osx" ]]; then
+    if [[ "${TRAVIS_OS_NAME}" == "osx" && -z "${BUILD_IOS}" ]]; then
+      cmake \
+        -DALSOFT_REQUIRE_COREAUDIO=ON \
+        -DALSOFT_EMBED_HRTF_DATA=YES \
+        .
+    fi
+  - >
+    if [[ "${TRAVIS_OS_NAME}" == "osx" && "${BUILD_IOS}" == "true" ]]; then
       cmake \
+        -GXcode \
+        -DCMAKE_TOOLCHAIN_FILE=cmake/ios.toolchain.cmake \
+        -DPLATFORM=OS \
         -DALSOFT_REQUIRE_COREAUDIO=ON \
         -DALSOFT_EMBED_HRTF_DATA=YES \
+        -DLIBTYPE=STATIC \
+        -DALSOFT_UTILS=OFF \
+        -DALSOFT_EXAMPLES=OFF \
         .
     fi
   - cmake --build . --clean-first
diff --git a/cmake/ios.toolchain.cmake b/cmake/ios.toolchain.cmake
new file mode 100644
index 00000000..e81d87c8
--- /dev/null
+++ b/cmake/ios.toolchain.cmake
@@ -0,0 +1,725 @@
+# 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.
+#
+# 2. 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.
+#
+# 3. 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 ([email protected])
+#
+# *****************************************************************************
+#      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 arguments control the behaviour of this toolchain:
+#
+# PLATFORM: (default "OS")
+#    OS = Build for iPhoneOS.
+#    OS64 = Build for arm64 iphoneOS.
+#    OS64COMBINED = Build for arm64 x86_64 iphoneOS. Combined into FAT STATIC lib (supported on 3.14+ of CMakewith "-G Xcode" argument ONLY)
+#    SIMULATOR = Build for x86 i386 iphoneOS Simulator.
+#    SIMULATOR64 = Build for x86_64 iphoneOS Simulator.
+#    TVOS = Build for arm64 tvOS.
+#    TVOSCOMBINED = Build for arm64 x86_64 tvOS. Combined into FAT STATIC lib (supported on 3.14+ of CMake with "-G Xcode" argument ONLY)
+#    SIMULATOR_TVOS = Build for x86_64 tvOS Simulator.
+#    WATCHOS = Build for armv7k arm64_32 for watchOS.
+#    WATCHOSCOMBINED = Build for armv7k arm64_32 x86_64 watchOS. Combined into FAT STATIC lib (supported on 3.14+ of CMake with "-G Xcode" argument ONLY)
+#    SIMULATOR_WATCHOS = Build for x86_64 for watchOS Simulator.
+#
+# CMAKE_OSX_SYSROOT: Path to the SDK to use.  By default this is
+#    automatically determined from PLATFORM and xcodebuild, but
+#    can also be manually specified (although this should not be required).
+#
+# CMAKE_DEVELOPER_ROOT: Path to the Developer directory for the 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).
+#
+# DEPLOYMENT_TARGET: Minimum SDK version to target. Default 2.0 on watchOS and 9.0 on tvOS+iOS
+#
+# 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)
+#
+# ENABLE_STRICT_TRY_COMPILE: (1|0) Enables or disables strict try_compile() on all Check* directives (will run linker
+#    to actually check if linking is possible). Default 0 (false, will set CMAKE_TRY_COMPILE_TARGET_TYPE to STATIC_LIBRARY)
+#
+# ARCHS: (armv7 armv7s armv7k arm64 arm64_32 i386 x86_64) If specified, will override the default architectures for the given PLATFORM
+#    OS = armv7 armv7s arm64 (if applicable)
+#    OS64 = arm64 (if applicable)
+#    SIMULATOR = i386
+#    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.
+# SDK_VERSION: Version of SDK being used.
+# CMAKE_OSX_ARCHITECTURES: Architectures being compiled for (generated from PLATFORM).
+# APPLE_TARGET_TRIPLE: Used by autoconf build systems. NOTE: If "ARCHS" are overridden, this will *NOT* be set!
+#
+# 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
+#   environment.  Thanks to the android-cmake project for providing the
+#   command.
+#
+# ******************************** DEPRECATIONS *******************************
+#
+# IOS_DEPLOYMENT_TARGET: (Deprecated) Alias to DEPLOYMENT_TARGET
+# CMAKE_IOS_DEVELOPER_ROOT: (Deprecated) Alias to CMAKE_DEVELOPER_ROOT
+# IOS_PLATFORM: (Deprecated) Alias to PLATFORM
+# IOS_ARCH: (Deprecated) Alias to ARCHS
+#
+# *****************************************************************************
+#
+
+# 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)
+
+# Cache what generator is used
+set(USED_CMAKE_GENERATOR "${CMAKE_GENERATOR}" CACHE STRING "Expose CMAKE_GENERATOR" FORCE)
+
+if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.14")
+  set(MODERN_CMAKE YES)
+endif()
+
+# 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}")
+
+######## ALIASES (DEPRECATION WARNINGS)
+
+if(DEFINED IOS_PLATFORM)
+  set(PLATFORM ${IOS_PLATFORM})
+  message(DEPRECATION "IOS_PLATFORM argument is DEPRECATED. Consider using the new PLATFORM argument instead.")
+endif()
+
+if(DEFINED IOS_DEPLOYMENT_TARGET)
+  set(DEPLOYMENT_TARGET ${IOS_DEPLOYMENT_TARGET})
+  message(DEPRECATION "IOS_DEPLOYMENT_TARGET argument is DEPRECATED. Consider using the new DEPLOYMENT_TARGET argument instead.")
+endif()
+
+if(DEFINED CMAKE_IOS_DEVELOPER_ROOT)
+  set(CMAKE_DEVELOPER_ROOT ${CMAKE_IOS_DEVELOPER_ROOT})
+  message(DEPRECATION "CMAKE_IOS_DEVELOPER_ROOT argument is DEPRECATED. Consider using the new CMAKE_DEVELOPER_ROOT argument instead.")
+endif()
+
+if(DEFINED IOS_ARCH)
+  set(ARCHS ${IOS_ARCH})
+  message(DEPRECATION "IOS_ARCH argument is DEPRECATED. Consider using the new ARCHS argument instead.")
+endif()
+
+######## END ALIASES
+
+# Unset the FORCE on cache variables if in try_compile()
+set(FORCE_CACHE FORCE)
+get_property(_CMAKE_IN_TRY_COMPILE GLOBAL PROPERTY IN_TRY_COMPILE)
+if(_CMAKE_IN_TRY_COMPILE)
+  unset(FORCE_CACHE)
+endif()
+
+# Default to building for iPhoneOS if not specified otherwise, and we cannot
+# determine the platform from the CMAKE_OSX_ARCHITECTURES variable. The use
+# of CMAKE_OSX_ARCHITECTURES is such that try_compile() projects can correctly
+# determine the value of PLATFORM from the root project, as
+# CMAKE_OSX_ARCHITECTURES is propagated to them by CMake.
+if(NOT DEFINED PLATFORM)
+  if (CMAKE_OSX_ARCHITECTURES)
+    if(CMAKE_OSX_ARCHITECTURES MATCHES ".*arm.*" AND CMAKE_OSX_SYSROOT MATCHES ".*iphoneos.*")
+      set(PLATFORM "OS")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "i386" AND CMAKE_OSX_SYSROOT MATCHES ".*iphonesimulator.*")
+      set(PLATFORM "SIMULATOR")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "x86_64" AND CMAKE_OSX_SYSROOT MATCHES ".*iphonesimulator.*")
+      set(PLATFORM "SIMULATOR64")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "arm64" AND CMAKE_OSX_SYSROOT MATCHES ".*appletvos.*")
+      set(PLATFORM "TVOS")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "x86_64" AND CMAKE_OSX_SYSROOT MATCHES ".*appletvsimulator.*")
+      set(PLATFORM "SIMULATOR_TVOS")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES ".*armv7k.*" AND CMAKE_OSX_SYSROOT MATCHES ".*watchos.*")
+      set(PLATFORM "WATCHOS")
+    elseif(CMAKE_OSX_ARCHITECTURES MATCHES "i386" AND CMAKE_OSX_SYSROOT MATCHES ".*watchsimulator.*")
+      set(PLATFORM "SIMULATOR_WATCHOS")
+    endif()
+  endif()
+  if (NOT PLATFORM)
+    set(PLATFORM "OS")
+  endif()
+endif()
+
+set(PLATFORM_INT "${PLATFORM}" CACHE STRING "Type of platform for which the build targets.")
+
+# Handle the case where we are targeting iOS and a version above 10.3.4 (32-bit support dropped officially)
+if(PLATFORM_INT STREQUAL "OS" AND DEPLOYMENT_TARGET VERSION_GREATER_EQUAL 10.3.4)
+  set(PLATFORM_INT "OS64")
+  message(STATUS "Targeting minimum SDK version ${DEPLOYMENT_TARGET}. Dropping 32-bit support.")
+elseif(PLATFORM_INT STREQUAL "SIMULATOR" AND DEPLOYMENT_TARGET VERSION_GREATER_EQUAL 10.3.4)
+  set(PLATFORM_INT "SIMULATOR64")
+  message(STATUS "Targeting minimum SDK version ${DEPLOYMENT_TARGET}. Dropping 32-bit support.")
+endif()
+
+# Determine the platform name and architectures for use in xcodebuild commands
+# from the specified PLATFORM name.
+if(PLATFORM_INT STREQUAL "OS")
+  set(SDK_NAME iphoneos)
+  if(NOT ARCHS)
+    set(ARCHS armv7 armv7s arm64)
+    set(APPLE_TARGET_TRIPLE_INT arm-apple-ios)
+  endif()
+elseif(PLATFORM_INT STREQUAL "OS64")
+  set(SDK_NAME iphoneos)
+  if(NOT ARCHS)
+    if (XCODE_VERSION VERSION_GREATER 10.0)
+      set(ARCHS arm64) # Add arm64e when Apple have fixed the integration issues with it, libarclite_iphoneos.a is currently missung bitcode markers for example
+    else()
+      set(ARCHS arm64)
+    endif()
+    set(APPLE_TARGET_TRIPLE_INT aarch64-apple-ios)
+  endif()
+elseif(PLATFORM_INT STREQUAL "OS64COMBINED")
+  set(SDK_NAME iphoneos)
+  if(MODERN_CMAKE)
+    if(NOT ARCHS)
+      if (XCODE_VERSION VERSION_GREATER 10.0)
+        set(ARCHS arm64 x86_64) # Add arm64e when Apple have fixed the integration issues with it, libarclite_iphoneos.a is currently missung bitcode markers for example
+      else()
+        set(ARCHS arm64 x86_64)
+      endif()
+      set(APPLE_TARGET_TRIPLE_INT aarch64-x86_64-apple-ios)
+    endif()
+  else()
+    message(FATAL_ERROR "Please make sure that you are running CMake 3.14+ to make the OS64COMBINED setting work")
+  endif()
+elseif(PLATFORM_INT STREQUAL "SIMULATOR")
+  set(SDK_NAME iphonesimulator)
+  if(NOT ARCHS)
+    set(ARCHS i386)
+    set(APPLE_TARGET_TRIPLE_INT i386-apple-ios)
+  endif()
+  message(DEPRECATION "SIMULATOR IS DEPRECATED. Consider using SIMULATOR64 instead.")
+elseif(PLATFORM_INT STREQUAL "SIMULATOR64")
+  set(SDK_NAME iphonesimulator)
+  if(NOT ARCHS)
+    set(ARCHS x86_64)
+    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-ios)
+  endif()
+elseif(PLATFORM_INT STREQUAL "TVOS")
+  set(SDK_NAME appletvos)
+  if(NOT ARCHS)
+    set(ARCHS arm64)
+    set(APPLE_TARGET_TRIPLE_INT aarch64-apple-tvos)
+  endif()
+elseif (PLATFORM_INT STREQUAL "TVOSCOMBINED")
+  set(SDK_NAME appletvos)
+  if(MODERN_CMAKE)
+    if(NOT ARCHS)
+      set(ARCHS arm64 x86_64)
+      set(APPLE_TARGET_TRIPLE_INT aarch64-x86_64-apple-tvos)
+    endif()
+  else()
+    message(FATAL_ERROR "Please make sure that you are running CMake 3.14+ to make the TVOSCOMBINED setting work")
+  endif()
+elseif(PLATFORM_INT STREQUAL "SIMULATOR_TVOS")
+  set(SDK_NAME appletvsimulator)
+  if(NOT ARCHS)
+    set(ARCHS x86_64)
+    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-tvos)
+  endif()
+elseif(PLATFORM_INT STREQUAL "WATCHOS")
+  set(SDK_NAME watchos)
+  if(NOT ARCHS)
+    if (XCODE_VERSION VERSION_GREATER 10.0)
+      set(ARCHS armv7k arm64_32)
+      set(APPLE_TARGET_TRIPLE_INT aarch64_32-apple-watchos)
+    else()
+      set(ARCHS armv7k)
+      set(APPLE_TARGET_TRIPLE_INT arm-apple-watchos)
+    endif()
+  endif()
+elseif(PLATFORM_INT STREQUAL "WATCHOSCOMBINED")
+  set(SDK_NAME watchos)
+  if(MODERN_CMAKE)
+    if(NOT ARCHS)
+      if (XCODE_VERSION VERSION_GREATER 10.0)
+        set(ARCHS armv7k arm64_32 i386)
+        set(APPLE_TARGET_TRIPLE_INT aarch64_32-i386-apple-watchos)
+      else()
+        set(ARCHS armv7k i386)
+        set(APPLE_TARGET_TRIPLE_INT arm-i386-apple-watchos)
+      endif()
+    endif()
+  else()
+    message(FATAL_ERROR "Please make sure that you are running CMake 3.14+ to make the WATCHOSCOMBINED setting work")
+  endif()
+elseif(PLATFORM_INT STREQUAL "SIMULATOR_WATCHOS")
+  set(SDK_NAME watchsimulator)
+  if(NOT ARCHS)
+    set(ARCHS i386)
+    set(APPLE_TARGET_TRIPLE_INT i386-apple-watchos)
+  endif()
+else()
+  message(FATAL_ERROR "Invalid PLATFORM: ${PLATFORM_INT}")
+endif()
+
+if(MODERN_CMAKE AND PLATFORM_INT MATCHES ".*COMBINED" AND NOT USED_CMAKE_GENERATOR MATCHES "Xcode")
+  message(FATAL_ERROR "The COMBINED options only work with Xcode generator, -G Xcode")
+endif()
+
+# If user did not specify the SDK root to use, then query xcodebuild for it.
+execute_process(COMMAND xcodebuild -version -sdk ${SDK_NAME} Path
+    OUTPUT_VARIABLE CMAKE_OSX_SYSROOT_INT
+    ERROR_QUIET
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+if (NOT DEFINED CMAKE_OSX_SYSROOT_INT AND NOT DEFINED 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: ${CMAKE_OSX_SYSROOT} "
+  "does not exist.")
+elseif(DEFINED CMAKE_OSX_SYSROOT_INT)
+   set(CMAKE_OSX_SYSROOT "${CMAKE_OSX_SYSROOT_INT}" CACHE INTERNAL "")
+endif()
+
+# Set Xcode property for SDKROOT as well if Xcode generator is used
+if(USED_CMAKE_GENERATOR MATCHES "Xcode")
+  set(CMAKE_OSX_SYSROOT "${SDK_NAME}" CACHE INTERNAL "")
+  if(NOT DEFINED CMAKE_XCODE_ATTRIBUTE_DEVELOPMENT_TEAM)
+    set(CMAKE_XCODE_ATTRIBUTE_DEVELOPMENT_TEAM "123456789A" CACHE INTERNAL "")
+  endif()
+endif()
+
+# Specify minimum version of deployment target.
+if(NOT DEFINED DEPLOYMENT_TARGET)
+  if (PLATFORM_INT STREQUAL "WATCHOS" OR PLATFORM_INT STREQUAL "SIMULATOR_WATCHOS")
+    # Unless specified, SDK version 2.0 is used by default as minimum target version (watchOS).
+    set(DEPLOYMENT_TARGET "2.0"
+            CACHE STRING "Minimum SDK version to build for." )
+  else()
+    # Unless specified, SDK version 9.0 is used by default as minimum target version (iOS, tvOS).
+    set(DEPLOYMENT_TARGET "9.0"
+            CACHE STRING "Minimum SDK version to build for." )
+  endif()
+  message(STATUS "Using the default min-version since DEPLOYMENT_TARGET not provided!")
+endif()
+
+# Use bitcode or not
+if(NOT DEFINED ENABLE_BITCODE AND NOT ARCHS MATCHES "((^|;|, )(i386|x86_64))+")
+  # Unless specified, enable bitcode support by default
+  message(STATUS "Enabling bitcode support by default. ENABLE_BITCODE not provided!")
+  set(ENABLE_BITCODE TRUE)
+elseif(NOT DEFINED ENABLE_BITCODE)
+  message(STATUS "Disabling bitcode support by default on simulators. ENABLE_BITCODE not provided for override!")
+  set(ENABLE_BITCODE FALSE)
+endif()
+set(ENABLE_BITCODE_INT ${ENABLE_BITCODE} CACHE BOOL "Whether or not to enable bitcode" ${FORCE_CACHE})
+# Use ARC or not
+if(NOT DEFINED ENABLE_ARC)
+  # Unless specified, enable ARC support by default
+  set(ENABLE_ARC TRUE)
+  message(STATUS "Enabling ARC support by default. ENABLE_ARC not provided!")
+endif()
+set(ENABLE_ARC_INT ${ENABLE_ARC} CACHE BOOL "Whether or not to enable ARC" ${FORCE_CACHE})
+# Use hidden visibility or not
+if(NOT DEFINED ENABLE_VISIBILITY)
+  # Unless specified, disable symbols visibility by default
+  set(ENABLE_VISIBILITY FALSE)
+  message(STATUS "Hiding symbols visibility by default. ENABLE_VISIBILITY not provided!")
+endif()
+set(ENABLE_VISIBILITY_INT ${ENABLE_VISIBILITY} CACHE BOOL "Whether or not to hide symbols (-fvisibility=hidden)" ${FORCE_CACHE})
+# Set strict compiler checks or not
+if(NOT DEFINED ENABLE_STRICT_TRY_COMPILE)
+  # Unless specified, disable strict try_compile()
+  set(ENABLE_STRICT_TRY_COMPILE FALSE)
+  message(STATUS "Using NON-strict compiler checks by default. ENABLE_STRICT_TRY_COMPILE not provided!")
+endif()
+set(ENABLE_STRICT_TRY_COMPILE_INT ${ENABLE_STRICT_TRY_COMPILE} CACHE BOOL "Whether or not to use strict compiler checks" ${FORCE_CACHE})
+# Get the SDK version information.
+execute_process(COMMAND xcodebuild -sdk ${CMAKE_OSX_SYSROOT} -version SDKVersion
+  OUTPUT_VARIABLE 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 DEFINED CMAKE_DEVELOPER_ROOT AND NOT USED_CMAKE_GENERATOR MATCHES "Xcode")
+  get_filename_component(PLATFORM_SDK_DIR ${CMAKE_OSX_SYSROOT} PATH)
+  get_filename_component(CMAKE_DEVELOPER_ROOT ${PLATFORM_SDK_DIR} PATH)
+  if (NOT DEFINED CMAKE_DEVELOPER_ROOT)
+    message(FATAL_ERROR "Invalid CMAKE_DEVELOPER_ROOT: "
+      "${CMAKE_DEVELOPER_ROOT} does not exist.")
+  endif()
+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 BUILD_LIBTOOL
+  ERROR_QUIET
+  OUTPUT_STRIP_TRAILING_WHITESPACE)
+message(STATUS "Using libtool: ${BUILD_LIBTOOL}")
+# Configure libtool to be used instead of ar + ranlib to build static libraries.
+# This is required on Xcode 7+, but should also work on previous versions of
+# Xcode.
+set(CMAKE_C_CREATE_STATIC_LIBRARY
+  "${BUILD_LIBTOOL} -static -o <TARGET> <LINK_FLAGS> <OBJECTS> ")
+set(CMAKE_CXX_CREATE_STATIC_LIBRARY
+  "${BUILD_LIBTOOL} -static -o <TARGET> <LINK_FLAGS> <OBJECTS> ")
+# Find the toolchain's provided install_name_tool if none is found on the host
+if(NOT CMAKE_INSTALL_NAME_TOOL)
+  execute_process(COMMAND xcrun -sdk ${CMAKE_OSX_SYSROOT} -find install_name_tool
+      OUTPUT_VARIABLE CMAKE_INSTALL_NAME_TOOL_INT
+      ERROR_QUIET
+      OUTPUT_STRIP_TRAILING_WHITESPACE)
+  set(CMAKE_INSTALL_NAME_TOOL ${CMAKE_INSTALL_NAME_TOOL_INT} CACHE STRING "" ${FORCE_CACHE})
+endif()
+# 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)
+if(SDK_NAME MATCHES "iphone")
+  set(CMAKE_SYSTEM_NAME iOS CACHE INTERNAL "" ${FORCE_CACHE})
+endif()
+# CMake 3.14+ support building for iOS, watchOS and tvOS out of the box.
+if(MODERN_CMAKE)
+  if(SDK_NAME MATCHES "appletv")
+    set(CMAKE_SYSTEM_NAME tvOS CACHE INTERNAL "" ${FORCE_CACHE})
+  elseif(SDK_NAME MATCHES "watch")
+    set(CMAKE_SYSTEM_NAME watchOS CACHE INTERNAL "" ${FORCE_CACHE})
+  endif()
+  # Provide flags for a combined FAT library build on newer CMake versions
+  if(PLATFORM_INT MATCHES ".*COMBINED")
+    set(CMAKE_XCODE_ATTRIBUTE_ONLY_ACTIVE_ARCH "NO" CACHE INTERNAL "" ${FORCE_CACHE})
+    set(CMAKE_IOS_INSTALL_COMBINED YES CACHE INTERNAL "" ${FORCE_CACHE})
+    message(STATUS "Will combine built (static) artifacts into FAT lib...")
+  endif()
+elseif(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.10")
+  # Legacy code path prior to CMake 3.14 or fallback if no SDK_NAME specified
+  set(CMAKE_SYSTEM_NAME iOS CACHE INTERNAL "" ${FORCE_CACHE})
+else()
+  # Legacy code path prior to CMake 3.14 or fallback if no SDK_NAME specified
+  set(CMAKE_SYSTEM_NAME Darwin CACHE INTERNAL "" ${FORCE_CACHE})
+endif()
+# Standard settings.
+set(CMAKE_SYSTEM_VERSION ${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)
+set(CMAKE_STRIP strip CACHE FILEPATH "" FORCE)
+# Set the architectures for which to build.
+set(CMAKE_OSX_ARCHITECTURES ${ARCHS} CACHE STRING "Build architecture for iOS")
+# Change the type of target generated for try_compile() so it'll work when cross-compiling, weak compiler checks
+if(ENABLE_STRICT_TRY_COMPILE_INT)
+  message(STATUS "Using strict compiler checks (default in CMake).")
+else()
+  set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
+endif()
+# All iOS/Darwin specific settings - some may be redundant.
+set(CMAKE_MACOSX_BUNDLE YES)
+set(CMAKE_XCODE_ATTRIBUTE_CODE_SIGNING_REQUIRED "NO")
+set(CMAKE_SHARED_LIBRARY_PREFIX "lib")
+set(CMAKE_SHARED_LIBRARY_SUFFIX ".dylib")
+set(CMAKE_SHARED_MODULE_PREFIX "lib")
+set(CMAKE_SHARED_MODULE_SUFFIX ".so")
+set(CMAKE_C_COMPILER_ABI ELF)
+set(CMAKE_CXX_COMPILER_ABI ELF)
+set(CMAKE_C_HAS_ISYSROOT 1)
+set(CMAKE_CXX_HAS_ISYSROOT 1)
+set(CMAKE_MODULE_EXISTS 1)
+set(CMAKE_DL_LIBS "")
+set(CMAKE_C_OSX_COMPATIBILITY_VERSION_FLAG "-compatibility_version ")
+set(CMAKE_C_OSX_CURRENT_VERSION_FLAG "-current_version ")
+set(CMAKE_CXX_OSX_COMPATIBILITY_VERSION_FLAG "${CMAKE_C_OSX_COMPATIBILITY_VERSION_FLAG}")
+set(CMAKE_CXX_OSX_CURRENT_VERSION_FLAG "${CMAKE_C_OSX_CURRENT_VERSION_FLAG}")
+
+if(ARCHS MATCHES "((^|;|, )(arm64|arm64e|x86_64))+")
+  set(CMAKE_C_SIZEOF_DATA_PTR 8)
+  set(CMAKE_CXX_SIZEOF_DATA_PTR 8)
+  if(ARCHS MATCHES "((^|;|, )(arm64|arm64e))+")
+    set(CMAKE_SYSTEM_PROCESSOR "aarch64")
+  else()
+    set(CMAKE_SYSTEM_PROCESSOR "x86_64")
+  endif()
+else()
+  set(CMAKE_C_SIZEOF_DATA_PTR 4)
+  set(CMAKE_CXX_SIZEOF_DATA_PTR 4)
+  set(CMAKE_SYSTEM_PROCESSOR "arm")
+endif()
+
+# Note that only Xcode 7+ supports the newer more specific:
+# -m${SDK_NAME}-version-min flags, older versions of Xcode use:
+# -m(ios/ios-simulator)-version-min instead.
+if(${CMAKE_VERSION} VERSION_LESS "3.11")
+  if(PLATFORM_INT STREQUAL "OS" OR PLATFORM_INT STREQUAL "OS64")
+    if(XCODE_VERSION VERSION_LESS 7.0)
+      set(SDK_NAME_VERSION_FLAGS
+        "-mios-version-min=${DEPLOYMENT_TARGET}")
+    else()
+      # Xcode 7.0+ uses flags we can build directly from SDK_NAME.
+      set(SDK_NAME_VERSION_FLAGS
+        "-m${SDK_NAME}-version-min=${DEPLOYMENT_TARGET}")
+    endif()
+  elseif(PLATFORM_INT STREQUAL "TVOS")
+    set(SDK_NAME_VERSION_FLAGS
+      "-mtvos-version-min=${DEPLOYMENT_TARGET}")
+  elseif(PLATFORM_INT STREQUAL "SIMULATOR_TVOS")
+    set(SDK_NAME_VERSION_FLAGS
+      "-mtvos-simulator-version-min=${DEPLOYMENT_TARGET}")
+  elseif(PLATFORM_INT STREQUAL "WATCHOS")
+    set(SDK_NAME_VERSION_FLAGS
+      "-mwatchos-version-min=${DEPLOYMENT_TARGET}")
+  elseif(PLATFORM_INT STREQUAL "SIMULATOR_WATCHOS")
+    set(SDK_NAME_VERSION_FLAGS
+      "-mwatchos-simulator-version-min=${DEPLOYMENT_TARGET}")
+  else()
+    # SIMULATOR or SIMULATOR64 both use -mios-simulator-version-min.
+    set(SDK_NAME_VERSION_FLAGS
+      "-mios-simulator-version-min=${DEPLOYMENT_TARGET}")
+  endif()
+else()
+  # Newer versions of CMake sets the version min flags correctly
+  set(CMAKE_OSX_DEPLOYMENT_TARGET ${DEPLOYMENT_TARGET} CACHE STRING
+      "Set CMake deployment target" ${FORCE_CACHE})
+endif()
+
+if(DEFINED APPLE_TARGET_TRIPLE_INT)
+  set(APPLE_TARGET_TRIPLE ${APPLE_TARGET_TRIPLE_INT} CACHE STRING
+          "Autoconf target triple compatible variable" ${FORCE_CACHE})
+endif()
+
+if(ENABLE_BITCODE_INT)
+  set(BITCODE "-fembed-bitcode")
+  set(CMAKE_XCODE_ATTRIBUTE_BITCODE_GENERATION_MODE "bitcode" CACHE INTERNAL "")
+  set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE "YES" CACHE INTERNAL "")
+else()
+  set(BITCODE "")
+  set(CMAKE_XCODE_ATTRIBUTE_ENABLE_BITCODE "NO" CACHE INTERNAL "")
+endif()
+
+if(ENABLE_ARC_INT)
+  set(FOBJC_ARC "-fobjc-arc")
+  set(CMAKE_XCODE_ATTRIBUTE_CLANG_ENABLE_OBJC_ARC "YES" CACHE INTERNAL "")
+else()
+  set(FOBJC_ARC "-fno-objc-arc")
+  set(CMAKE_XCODE_ATTRIBUTE_CLANG_ENABLE_OBJC_ARC "NO" CACHE INTERNAL "")
+endif()
+
+if(NOT ENABLE_VISIBILITY_INT)
+  set(VISIBILITY "-fvisibility=hidden")
+  set(CMAKE_XCODE_ATTRIBUTE_GCC_SYMBOLS_PRIVATE_EXTERN "YES" CACHE INTERNAL "")
+else()
+  set(VISIBILITY "")
+  set(CMAKE_XCODE_ATTRIBUTE_GCC_SYMBOLS_PRIVATE_EXTERN "NO" CACHE INTERNAL "")
+endif()
+
+if(NOT IOS_TOOLCHAIN_HAS_RUN)
+  #Check if Xcode generator is used, since that will handle these flags automagically
+  if(USED_CMAKE_GENERATOR MATCHES "Xcode")
+    message(STATUS "Not setting any manual command-line buildflags, since Xcode is selected as generator.")
+  else()
+    set(CMAKE_C_FLAGS
+    "${SDK_NAME_VERSION_FLAGS} ${BITCODE} -fobjc-abi-version=2 ${FOBJC_ARC} ${CMAKE_C_FLAGS}")
+    # Hidden visibilty is required for C++ on iOS.
+    set(CMAKE_CXX_FLAGS
+    "${SDK_NAME_VERSION_FLAGS} ${BITCODE} ${VISIBILITY} -fvisibility-inlines-hidden -fobjc-abi-version=2 ${FOBJC_ARC} ${CMAKE_CXX_FLAGS}")
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS} -O0 -g ${CMAKE_CXX_FLAGS_DEBUG}")
+    set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS} -DNDEBUG -Os -ffast-math ${CMAKE_CXX_FLAGS_MINSIZEREL}")
+    set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS} -DNDEBUG -O2 -g -ffast-math ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS} -DNDEBUG -O3 -ffast-math ${CMAKE_CXX_FLAGS_RELEASE}")
+    set(CMAKE_C_LINK_FLAGS "${SDK_NAME_VERSION_FLAGS} -Wl,-search_paths_first ${CMAKE_C_LINK_FLAGS}")
+    set(CMAKE_CXX_LINK_FLAGS "${SDK_NAME_VERSION_FLAGS}  -Wl,-search_paths_first ${CMAKE_CXX_LINK_FLAGS}")
+    set(CMAKE_ASM_FLAGS "${CFLAGS} -x assembler-with-cpp")
+
+    # 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.
+    set(VARS_TO_FORCE_IN_CACHE
+      CMAKE_C_FLAGS
+      CMAKE_CXX_FLAGS
+      CMAKE_CXX_FLAGS_DEBUG
+      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 "" ${FORCE_CACHE})
+    endforeach()
+  endif()
+
+  ## Print status messages to inform of the current state
+  message(STATUS "Configuring ${SDK_NAME} build for platform: ${PLATFORM_INT}, architecture(s): ${ARCHS}")
+  message(STATUS "Using SDK: ${CMAKE_OSX_SYSROOT_INT}")
+  if(DEFINED APPLE_TARGET_TRIPLE)
+    message(STATUS "Autoconf target triple: ${APPLE_TARGET_TRIPLE}")
+  endif()
+  message(STATUS "Using minimum deployment version: ${DEPLOYMENT_TARGET}"
+      " (SDK version: ${SDK_VERSION})")
+  if(MODERN_CMAKE)
+    message(STATUS "Merging integrated CMake 3.14+ iOS,tvOS,watchOS,macOS toolchain(s) with this toolchain!")
+  endif()
+  if(USED_CMAKE_GENERATOR MATCHES "Xcode")
+    message(STATUS "Using Xcode version: ${XCODE_VERSION}")
+  endif()
+  if(DEFINED SDK_NAME_VERSION_FLAGS)
+    message(STATUS "Using version flags: ${SDK_NAME_VERSION_FLAGS}")
+  endif()
+  message(STATUS "Using a data_ptr size of: ${CMAKE_CXX_SIZEOF_DATA_PTR}")
+  message(STATUS "Using install_name_tool: ${CMAKE_INSTALL_NAME_TOOL}")
+  if(ENABLE_BITCODE_INT)
+    message(STATUS "Enabling bitcode support.")
+  else()
+    message(STATUS "Disabling bitcode support.")
+  endif()
+
+  if(ENABLE_ARC_INT)
+    message(STATUS "Enabling ARC support.")
+  else()
+    message(STATUS "Disabling ARC support.")
+  endif()
+
+  if(NOT ENABLE_VISIBILITY_INT)
+    message(STATUS "Hiding symbols (-fvisibility=hidden).")
+  endif()
+endif()
+
+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 -Wl,-headerpad_max_install_names")
+set(CMAKE_SHARED_MODULE_CREATE_C_FLAGS "-bundle -Wl,-headerpad_max_install_names")
+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 ".tbd" ".dylib" ".so" ".a")
+set(CMAKE_SHARED_LIBRARY_SONAME_C_FLAG "-install_name")
+
+# Set the find root to the iOS developer roots and to user defined paths.
+set(CMAKE_FIND_ROOT_PATH ${CMAKE_OSX_SYSROOT_INT} ${CMAKE_PREFIX_PATH} CACHE STRING "Root path that will be prepended
+ to all search paths")
+# Default to searching for frameworks first.
+set(CMAKE_FIND_FRAMEWORK FIRST)
+# Set up the default search directories for frameworks.
+set(CMAKE_FRAMEWORK_PATH
+  ${CMAKE_DEVELOPER_ROOT}/Library/PrivateFrameworks
+  ${CMAKE_OSX_SYSROOT_INT}/System/Library/Frameworks
+  ${CMAKE_FRAMEWORK_PATH} CACHE STRING "Frameworks search paths" ${FORCE_CACHE})
+
+set(IOS_TOOLCHAIN_HAS_RUN TRUE CACHE BOOL "Has the CMake toolchain run already?" ${FORCE_CACHE})
+
+# By default, search both the specified iOS SDK and the remainder of the host filesystem.
+if(NOT CMAKE_FIND_ROOT_PATH_MODE_PROGRAM)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM BOTH CACHE STRING "" ${FORCE_CACHE})
+endif()
+if(NOT CMAKE_FIND_ROOT_PATH_MODE_LIBRARY)
+  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY BOTH CACHE STRING "" ${FORCE_CACHE})
+endif()
+if(NOT CMAKE_FIND_ROOT_PATH_MODE_INCLUDE)
+  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE BOTH CACHE STRING "" ${FORCE_CACHE})
+endif()
+if(NOT CMAKE_FIND_ROOT_PATH_MODE_PACKAGE)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE BOTH CACHE STRING "" ${FORCE_CACHE})
+endif()
+
+#
+# Some helper-macros below to simplify and beautify the CMakeFile
+#
+
+# This little macro lets you set any Xcode specific property.
+macro(set_xcode_property TARGET XCODE_PROPERTY XCODE_VALUE XCODE_RELVERSION)
+  set(XCODE_RELVERSION_I "${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(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE NEVER)
+  set(IOS FALSE)
+  find_package(${ARGN})
+  set(IOS TRUE)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM BOTH)
+  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY BOTH)
+  set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE BOTH)
+  set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE BOTH)
+endmacro(find_host_package)