Languages: Add support for Objective-C

Add entries in Modules and Modules/Platform to support
Objective-C compiler determination and identification.
Add Modules to check Objective-C compiler flags, source
compilations, program checks, etc...

Use OBJC as the designator of the language, eg:

project(foo OBJC)

Add various tests for Objective-C language features.  Add
tests to preserve C++ handling of .m and .mm files when
OBJC is not a configured language.

Co-Authored-By: Cristian Adam <[email protected]>

Help/command/enable_language.rst

@@ -1,7 +1,7 @@
 enable_language
 ---------------
 
-Enable a language (CXX/C/Fortran/etc)
+Enable a language (CXX/C/OBJC/Fortran/etc)
 
 .. code-block:: cmake
 
@@ -10,7 +10,7 @@ Enable a language (CXX/C/Fortran/etc)
 Enables support for the named language in CMake.  This is
 the same as the :command:`project` command but does not create any of the extra
 variables that are created by the project command.  Example languages
-are ``CXX``, ``C``, ``CUDA``, ``Fortran``, and ``ASM``.
+are ``CXX``, ``C``, ``CUDA``, ``OBJC``, ``Fortran``, and ``ASM``.
 
 If enabling ``ASM``, enable it last so that CMake can check whether
 compilers for other languages like ``C`` work for assembly too.

Help/command/project.rst

@@ -87,7 +87,8 @@ The options are:
   Can also be specified without ``LANGUAGES`` keyword per the first, short signature.
 
   Selects which programming languages are needed to build the project.
-  Supported languages include ``C``, ``CXX`` (i.e.  C++), ``CUDA``, ``Fortran``, and ``ASM``.
+  Supported languages include ``C``, ``CXX`` (i.e.  C++), ``CUDA``, ``OBJC`` (i.e. Objective-C),
+  ``Fortran``, and ``ASM``.
   By default ``C`` and ``CXX`` are enabled if no language options are given.
   Specify language ``NONE``, or use the ``LANGUAGES`` keyword and list no languages,
   to skip enabling any languages.

Help/manual/cmake-generator-expressions.7.rst

@@ -130,6 +130,11 @@ Variable Queries
   ``1`` if the CMake's compiler id of the CUDA compiler matches any one
   of the entries in ``compiler_ids``, otherwise ``0``.
   See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
+``$<OBJC_COMPILER_ID:compiler_ids>``
+  where ``compiler_ids`` is a comma-separated list.
+  ``1`` if the CMake's compiler id of the Objective-C compiler matches any one
+  of the entries in ``compiler_ids``, otherwise ``0``.
+  See also the :variable:`CMAKE_<LANG>_COMPILER_ID` variable.
 ``$<Fortran_COMPILER_ID:compiler_ids>``
   where ``compiler_ids`` is a comma-separated list.
   ``1`` if the CMake's compiler id of the Fortran compiler matches any one
@@ -413,6 +418,9 @@ Variable Queries
 ``$<CUDA_COMPILER_VERSION>``
   The version of the CUDA compiler used.
   See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
+``$<OBJC_COMPILER_VERSION>``
+  The version of the OBJC compiler used.
+  See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.
 ``$<Fortran_COMPILER_VERSION>``
   The version of the Fortran compiler used.
   See also the :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable.

Help/manual/cmake-modules.7.rst

@@ -36,6 +36,9 @@ These modules are loaded using the :command:`include` command.
    /module/CheckIncludeFiles
    /module/CheckLanguage
    /module/CheckLibraryExists
+   /module/CheckOBJCCompilerFlag
+   /module/CheckOBJCSourceCompiles
+   /module/CheckOBJCSourceRuns
    /module/CheckPIESupported
    /module/CheckPrototypeDefinition
    /module/CheckStructHasMember

Help/module/CheckOBJCCompilerFlag.rst

@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/CheckOBJCCompilerFlag.cmake

Help/module/CheckOBJCSourceCompiles.rst

@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/CheckOBJCSourceCompiles.cmake

Help/module/CheckOBJCSourceRuns.rst

@@ -0,0 +1 @@
+.. cmake-module:: ../../Modules/CheckOBJCSourceRuns.cmake

Modules/CMakeCXXCompiler.cmake.in

@@ -42,8 +42,17 @@ if(CMAKE_COMPILER_IS_MINGW)
   set(MINGW 1)
 endif()
 set(CMAKE_CXX_COMPILER_ID_RUN 1)
+set(CMAKE_CXX_SOURCE_FILE_EXTENSIONS C;M;c++;cc;cpp;cxx;m;mm;CPP)
 set(CMAKE_CXX_IGNORE_EXTENSIONS inl;h;hpp;HPP;H;o;O;obj;OBJ;def;DEF;rc;RC)
-set(CMAKE_CXX_SOURCE_FILE_EXTENSIONS C;M;c++;cc;cpp;cxx;mm;CPP)
+
+foreach (lang OBJC)
+  if (CMAKE_${lang}_COMPILER_ID_RUN)
+    foreach(extension IN LISTS CMAKE_${lang}_SOURCE_FILE_EXTENSIONS)
+      list(REMOVE_ITEM CMAKE_CXX_SOURCE_FILE_EXTENSIONS ${extension})
+    endforeach()
+  endif()
+endforeach()
+
 set(CMAKE_CXX_LINKER_PREFERENCE 30)
 set(CMAKE_CXX_LINKER_PREFERENCE_PROPAGATES 1)
 

Modules/CMakeDetermineOBJCCompiler.cmake

@@ -0,0 +1,189 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+
+# determine the compiler to use for Objective-C programs
+# NOTE, a generator may set CMAKE_OBJC_COMPILER before
+# loading this file to force a compiler.
+# use environment variable OBJC first if defined by user, next use
+# the cmake variable CMAKE_GENERATOR_OBJC which can be defined by a generator
+# as a default compiler
+#
+# Sets the following variables:
+#   CMAKE_OBJC_COMPILER
+#   CMAKE_AR
+#   CMAKE_RANLIB
+#   CMAKE_COMPILER_IS_GNUOBJC
+#   CMAKE_COMPILER_IS_CLANGOBJC
+#
+# If not already set before, it also sets
+#   _CMAKE_TOOLCHAIN_PREFIX
+
+include(${CMAKE_ROOT}/Modules/CMakeDetermineCompiler.cmake)
+
+# Load system-specific compiler preferences for this language.
+include(Platform/${CMAKE_SYSTEM_NAME}-Determine-OBJC OPTIONAL)
+include(Platform/${CMAKE_SYSTEM_NAME}-OBJC OPTIONAL)
+if(NOT CMAKE_OBJC_COMPILER_NAMES)
+  set(CMAKE_OBJC_COMPILER_NAMES clang)
+endif()
+
+if("${CMAKE_GENERATOR}" MATCHES "Xcode")
+  set(CMAKE_OBJC_COMPILER_XCODE_TYPE sourcecode.c.objc)
+else()
+  if(NOT CMAKE_OBJC_COMPILER)
+    set(CMAKE_OBJC_COMPILER_INIT NOTFOUND)
+
+    # prefer the environment variable OBJC
+    if($ENV{OBJC} MATCHES ".+")
+      get_filename_component(CMAKE_OBJC_COMPILER_INIT $ENV{OBJC} PROGRAM PROGRAM_ARGS CMAKE_OBJC_FLAGS_ENV_INIT)
+      if(CMAKE_OBJC_FLAGS_ENV_INIT)
+        set(CMAKE_OBJC_COMPILER_ARG1 "${CMAKE_OBJC_FLAGS_ENV_INIT}" CACHE STRING "First argument to Objective-C compiler")
+      endif()
+      if(NOT EXISTS ${CMAKE_OBJC_COMPILER_INIT})
+        message(FATAL_ERROR "Could not find compiler set in environment variable OBJC:\n$ENV{OBJC}.")
+      endif()
+    endif()
+
+    # next try prefer the compiler specified by the generator
+    if(CMAKE_GENERATOR_OBJC)
+      if(NOT CMAKE_OBJC_COMPILER_INIT)
+        set(CMAKE_OBJC_COMPILER_INIT ${CMAKE_GENERATOR_OBJC})
+      endif()
+    endif()
+
+    # finally list compilers to try
+    if(NOT CMAKE_OBJC_COMPILER_INIT)
+      set(CMAKE_OBJC_COMPILER_LIST ${_CMAKE_TOOLCHAIN_PREFIX}cc ${_CMAKE_TOOLCHAIN_PREFIX}gcc clang)
+    endif()
+
+    _cmake_find_compiler(OBJC)
+
+  else()
+    # we only get here if CMAKE_OBJC_COMPILER was specified using -D or a pre-made CMakeCache.txt
+    # (e.g. via ctest) or set in CMAKE_TOOLCHAIN_FILE
+    # if CMAKE_OBJC_COMPILER is a list of length 2, use the first item as
+    # CMAKE_OBJC_COMPILER and the 2nd one as CMAKE_OBJC_COMPILER_ARG1
+
+    list(LENGTH CMAKE_OBJC_COMPILER _CMAKE_OBJC_COMPILER_LIST_LENGTH)
+    if("${_CMAKE_OBJC_COMPILER_LIST_LENGTH}" EQUAL 2)
+      list(GET CMAKE_OBJC_COMPILER 1 CMAKE_OBJC_COMPILER_ARG1)
+      list(GET CMAKE_OBJC_COMPILER 0 CMAKE_OBJC_COMPILER)
+    endif()
+
+    # if a compiler was specified by the user but without path,
+    # now try to find it with the full path
+    # if it is found, force it into the cache,
+    # if not, don't overwrite the setting (which was given by the user) with "NOTFOUND"
+    # if the C compiler already had a path, reuse it for searching the CXX compiler
+    get_filename_component(_CMAKE_USER_OBJC_COMPILER_PATH "${CMAKE_OBJC_COMPILER}" PATH)
+    if(NOT _CMAKE_USER_OBJC_COMPILER_PATH)
+      find_program(CMAKE_OBJC_COMPILER_WITH_PATH NAMES ${CMAKE_OBJC_COMPILER})
+      if(CMAKE_OBJC_COMPILER_WITH_PATH)
+        set(CMAKE_OBJC_COMPILER ${CMAKE_OBJC_COMPILER_WITH_PATH} CACHE STRING "Objective-C compiler" FORCE)
+      endif()
+      unset(CMAKE_OBJC_COMPILER_WITH_PATH CACHE)
+    endif()
+  endif()
+  mark_as_advanced(CMAKE_OBJC_COMPILER)
+
+  # Each entry in this list is a set of extra flags to try
+  # adding to the compile line to see if it helps produce
+  # a valid identification file.
+  set(CMAKE_OBJC_COMPILER_ID_TEST_FLAGS_FIRST)
+  set(CMAKE_OBJC_COMPILER_ID_TEST_FLAGS
+    # Try compiling to an object file only.
+    "-c"
+
+    )
+endif()
+
+# Build a small source file to identify the compiler.
+if(NOT CMAKE_OBJC_COMPILER_ID_RUN)
+  set(CMAKE_OBJC_COMPILER_ID_RUN 1)
+
+  # Try to identify the compiler.
+  set(CMAKE_OBJC_COMPILER_ID)
+  file(READ ${CMAKE_ROOT}/Modules/CMakePlatformId.h.in
+    CMAKE_OBJC_COMPILER_ID_PLATFORM_CONTENT)
+
+  # Match the link line from xcodebuild output of the form
+  #  Ld ...
+  #      ...
+  #      /path/to/cc ...CompilerIdOBJC/...
+  # to extract the compiler front-end for the language.
+  set(CMAKE_OBJC_COMPILER_ID_TOOL_MATCH_REGEX "\nLd[^\n]*(\n[ \t]+[^\n]*)*\n[ \t]+([^ \t\r\n]+)[^\r\n]*-o[^\r\n]*CompilerIdOBJC/(\\./)?(CompilerIdOBJC.(framework|xctest)/)?CompilerIdOBJC[ \t\n\\\"]")
+  set(CMAKE_OBJC_COMPILER_ID_TOOL_MATCH_INDEX 2)
+
+  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerId.cmake)
+  CMAKE_DETERMINE_COMPILER_ID(OBJC OBJCCFLAGS CMakeOBJCCompilerId.m)
+
+  # Set old compiler and platform id variables.
+  if(CMAKE_OBJC_COMPILER_ID STREQUAL "GNU")
+    set(CMAKE_COMPILER_IS_GNUOBJC 1)
+  endif()
+  if(CMAKE_OBJC_COMPILER_ID STREQUAL "Clang")
+    set(CMAKE_COMPILER_IS_CLANGOBJC 1)
+  endif()
+endif()
+
+if (NOT _CMAKE_TOOLCHAIN_LOCATION)
+  get_filename_component(_CMAKE_TOOLCHAIN_LOCATION "${CMAKE_OBJC_COMPILER}" PATH)
+endif ()
+
+# If we have a gcc cross compiler, they have usually some prefix, like
+# e.g. powerpc-linux-gcc, arm-elf-gcc or i586-mingw32msvc-gcc, optionally
+# with a 3-component version number at the end (e.g. arm-eabi-gcc-4.5.2).
+# The other tools of the toolchain usually have the same prefix
+# NAME_WE cannot be used since then this test will fail for names like
+# "arm-unknown-nto-qnx6.3.0-gcc.exe", where BASENAME would be
+# "arm-unknown-nto-qnx6" instead of the correct "arm-unknown-nto-qnx6.3.0-"
+if (CMAKE_CROSSCOMPILING  AND NOT _CMAKE_TOOLCHAIN_PREFIX)
+
+  if(CMAKE_OBJC_COMPILER_ID MATCHES "GNU|Clang|QCC")
+    get_filename_component(COMPILER_BASENAME "${CMAKE_OBJC_COMPILER}" NAME)
+    if (COMPILER_BASENAME MATCHES "^(.+-)(clang|g?cc)(-[0-9]+(\\.[0-9]+)*)?(-[^.]+)?(\\.exe)?$")
+      set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
+      set(_CMAKE_COMPILER_SUFFIX ${CMAKE_MATCH_5})
+    elseif(CMAKE_OBJC_COMPILER_ID MATCHES "Clang")
+      if(CMAKE_OBJC_COMPILER_TARGET)
+        set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_OBJC_COMPILER_TARGET}-)
+      endif()
+    elseif(COMPILER_BASENAME MATCHES "qcc(\\.exe)?$")
+      if(CMAKE_OBJC_COMPILER_TARGET MATCHES "gcc_nto([a-z0-9]+_[0-9]+|[^_le]+)(le)?")
+        set(_CMAKE_TOOLCHAIN_PREFIX nto${CMAKE_MATCH_1}-)
+      endif()
+    endif ()
+
+    # if "llvm-" is part of the prefix, remove it, since llvm doesn't have its own binutils
+    # but uses the regular ar, objcopy, etc. (instead of llvm-objcopy etc.)
+    if ("${_CMAKE_TOOLCHAIN_PREFIX}" MATCHES "(.+-)?llvm-$")
+      set(_CMAKE_TOOLCHAIN_PREFIX ${CMAKE_MATCH_1})
+    endif ()
+  endif()
+
+endif ()
+
+set(_CMAKE_PROCESSING_LANGUAGE "OBJC")
+include(CMakeFindBinUtils)
+include(Compiler/${CMAKE_OBJC_COMPILER_ID}-FindBinUtils OPTIONAL)
+unset(_CMAKE_PROCESSING_LANGUAGE)
+
+if(CMAKE_OBJC_COMPILER_ARCHITECTURE_ID)
+  set(_SET_CMAKE_OBJC_COMPILER_ARCHITECTURE_ID
+    "set(CMAKE_OBJC_COMPILER_ARCHITECTURE_ID ${CMAKE_OBJC_COMPILER_ARCHITECTURE_ID})")
+else()
+  set(_SET_CMAKE_OBJC_COMPILER_ARCHITECTURE_ID "")
+endif()
+
+if(CMAKE_OBJC_XCODE_ARCHS)
+  set(SET_CMAKE_XCODE_ARCHS
+    "set(CMAKE_XCODE_ARCHS \"${CMAKE_OBJC_XCODE_ARCHS}\")")
+endif()
+
+# configure variables set in this file for fast reload later on
+configure_file(${CMAKE_ROOT}/Modules/CMakeOBJCCompiler.cmake.in
+  ${CMAKE_PLATFORM_INFO_DIR}/CMakeOBJCCompiler.cmake
+  @ONLY
+  )
+set(CMAKE_OBJC_COMPILER_ENV_VAR "OBJC")

Modules/CMakeOBJCCompiler.cmake.in

@@ -0,0 +1,69 @@
+set(CMAKE_OBJC_COMPILER "@CMAKE_OBJC_COMPILER@")
+set(CMAKE_OBJC_COMPILER_ARG1 "@CMAKE_OBJC_COMPILER_ARG1@")
+set(CMAKE_OBJC_COMPILER_ID "@CMAKE_OBJC_COMPILER_ID@")
+set(CMAKE_OBJC_COMPILER_VERSION "@CMAKE_OBJC_COMPILER_VERSION@")
+set(CMAKE_OBJC_COMPILER_VERSION_INTERNAL "@CMAKE_OBJC_COMPILER_VERSION_INTERNAL@")
+set(CMAKE_OBJC_COMPILER_WRAPPER "@CMAKE_OBJC_COMPILER_WRAPPER@")
+set(CMAKE_OBJC_STANDARD_COMPUTED_DEFAULT "@CMAKE_OBJC_STANDARD_COMPUTED_DEFAULT@")
+set(CMAKE_OBJC_COMPILE_FEATURES "@CMAKE_OBJC_COMPILE_FEATURES@")
+set(CMAKE_OBJC90_COMPILE_FEATURES "@CMAKE_OBJC90_COMPILE_FEATURES@")
+set(CMAKE_OBJC99_COMPILE_FEATURES "@CMAKE_OBJC99_COMPILE_FEATURES@")
+set(CMAKE_OBJC11_COMPILE_FEATURES "@CMAKE_OBJC11_COMPILE_FEATURES@")
+
+set(CMAKE_OBJC_PLATFORM_ID "@CMAKE_OBJC_PLATFORM_ID@")
+set(CMAKE_OBJC_SIMULATE_ID "@CMAKE_OBJC_SIMULATE_ID@")
+set(CMAKE_OBJC_COMPILER_FRONTEND_VARIANT "@CMAKE_OBJC_COMPILER_FRONTEND_VARIANT@")
+set(CMAKE_OBJC_SIMULATE_VERSION "@CMAKE_OBJC_SIMULATE_VERSION@")
+@_SET_CMAKE_OBJC_COMPILER_ARCHITECTURE_ID@
+@SET_CMAKE_XCODE_ARCHS@
+set(CMAKE_AR "@CMAKE_AR@")
+set(CMAKE_OBJC_COMPILER_AR "@CMAKE_OBJC_COMPILER_AR@")
+set(CMAKE_RANLIB "@CMAKE_RANLIB@")
+set(CMAKE_OBJC_COMPILER_RANLIB "@CMAKE_OBJC_COMPILER_RANLIB@")
+set(CMAKE_LINKER "@CMAKE_LINKER@")
+set(CMAKE_MT "@CMAKE_MT@")
+set(CMAKE_COMPILER_IS_GNUOBJC @CMAKE_COMPILER_IS_GNUOBJC@)
+set(CMAKE_OBJC_COMPILER_LOADED 1)
+set(CMAKE_OBJC_COMPILER_WORKS @CMAKE_OBJC_COMPILER_WORKS@)
+set(CMAKE_OBJC_ABI_COMPILED @CMAKE_OBJC_ABI_COMPILED@)
+
+set(CMAKE_OBJC_COMPILER_ENV_VAR "OBJC")
+
+set(CMAKE_OBJC_COMPILER_ID_RUN 1)
+set(CMAKE_OBJC_SOURCE_FILE_EXTENSIONS m)
+set(CMAKE_OBJC_IGNORE_EXTENSIONS h;H;o;O)
+set(CMAKE_OBJC_LINKER_PREFERENCE 5)
+
+foreach (lang C CXX OBJCXX)
+  foreach(extension IN LISTS CMAKE_OBJC_SOURCE_FILE_EXTENSIONS)
+    if (CMAKE_${lang}_COMPILER_ID_RUN)
+      list(REMOVE_ITEM CMAKE_${lang}_SOURCE_FILE_EXTENSIONS ${extension})
+    endif()
+  endforeach()
+endforeach()
+
+# Save compiler ABI information.
+set(CMAKE_OBJC_SIZEOF_DATA_PTR "@CMAKE_OBJC_SIZEOF_DATA_PTR@")
+set(CMAKE_OBJC_COMPILER_ABI "@CMAKE_OBJC_COMPILER_ABI@")
+set(CMAKE_OBJC_LIBRARY_ARCHITECTURE "@CMAKE_OBJC_LIBRARY_ARCHITECTURE@")
+
+if(CMAKE_OBJC_SIZEOF_DATA_PTR)
+  set(CMAKE_SIZEOF_VOID_P "${CMAKE_OBJC_SIZEOF_DATA_PTR}")
+endif()
+
+if(CMAKE_OBJC_COMPILER_ABI)
+  set(CMAKE_INTERNAL_PLATFORM_ABI "${CMAKE_OBJC_COMPILER_ABI}")
+endif()
+
+if(CMAKE_OBJC_LIBRARY_ARCHITECTURE)
+  set(CMAKE_LIBRARY_ARCHITECTURE "@CMAKE_OBJC_LIBRARY_ARCHITECTURE@")
+endif()
+
+@CMAKE_OBJC_COMPILER_CUSTOM_CODE@
+@CMAKE_OBJC_SYSROOT_FLAG_CODE@
+@CMAKE_OBJC_OSX_DEPLOYMENT_TARGET_FLAG_CODE@
+
+set(CMAKE_OBJC_IMPLICIT_INCLUDE_DIRECTORIES "@CMAKE_OBJC_IMPLICIT_INCLUDE_DIRECTORIES@")
+set(CMAKE_OBJC_IMPLICIT_LINK_LIBRARIES "@CMAKE_OBJC_IMPLICIT_LINK_LIBRARIES@")
+set(CMAKE_OBJC_IMPLICIT_LINK_DIRECTORIES "@CMAKE_OBJC_IMPLICIT_LINK_DIRECTORIES@")
+set(CMAKE_OBJC_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES "@CMAKE_OBJC_IMPLICIT_LINK_FRAMEWORK_DIRECTORIES@")

Modules/CMakeOBJCCompilerABI.m

@@ -0,0 +1,20 @@
+#ifdef __cplusplus
+# error "A C++ compiler has been selected for Objective-C."
+#endif
+
+/*--------------------------------------------------------------------------*/
+
+#include "CMakeCompilerABI.h"
+
+/*--------------------------------------------------------------------------*/
+
+int main(int argc, char *argv[])
+{
+  int require = 0;
+  require += info_sizeof_dptr[argc];
+#if defined(ABI_ID)
+  require += info_abi[argc];
+#endif
+  (void)argv;
+  return require;
+}

Modules/CMakeOBJCCompilerId.m.in

@@ -0,0 +1,63 @@
+#ifdef __cplusplus
+# error "An Objective-C++ compiler has been selected for Objective-C."
+#endif
+
+@CMAKE_OBJC_COMPILER_ID_CONTENT@
+
+/* Construct the string literal in pieces to prevent the source from
+   getting matched.  Store it in a pointer rather than an array
+   because some compilers will just produce instructions to fill the
+   array rather than assigning a pointer to a static array.  */
+char const* info_compiler = "INFO" ":" "compiler[" COMPILER_ID "]";
+#ifdef SIMULATE_ID
+char const* info_simulate = "INFO" ":" "simulate[" SIMULATE_ID "]";
+#endif
+
+#ifdef __QNXNTO__
+char const* qnxnto = "INFO" ":" "qnxnto[]";
+#endif
+
+@CMAKE_OBJC_COMPILER_ID_PLATFORM_CONTENT@
+@CMAKE_OBJC_COMPILER_ID_ERROR_FOR_TEST@
+
+#if !defined(__STDC__)
+# if (defined(_MSC_VER) && !defined(__clang__)) \
+  || (defined(__ibmxl__) || defined(__IBMC__))
+#  define C_DIALECT "90"
+# else
+#  define C_DIALECT
+# endif
+#elif __STDC_VERSION__ >= 201000L
+# define C_DIALECT "11"
+#elif __STDC_VERSION__ >= 199901L
+# define C_DIALECT "99"
+#else
+# define C_DIALECT "90"
+#endif
+const char* info_language_dialect_default =
+  "INFO" ":" "dialect_default[" C_DIALECT "]";
+
+/*--------------------------------------------------------------------------*/
+
+int main(int argc, char* argv[])
+{
+  int require = 0;
+  require += info_compiler[argc];
+  require += info_platform[argc];
+  require += info_arch[argc];
+#ifdef COMPILER_VERSION_MAJOR
+  require += info_version[argc];
+#endif
+#ifdef COMPILER_VERSION_INTERNAL
+  require += info_version_internal[argc];
+#endif
+#ifdef SIMULATE_ID
+  require += info_simulate[argc];
+#endif
+#ifdef SIMULATE_VERSION_MAJOR
+  require += info_simulate_version[argc];
+#endif
+  require += info_language_dialect_default[argc];
+  (void)argv;
+  return require;
+}

Modules/CMakeOBJCInformation.cmake

@@ -0,0 +1,188 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+
+# This file sets the basic flags for the Objective-C language in CMake.
+# It also loads the available platform file for the system-compiler
+# if it exists.
+# It also loads a system - compiler - processor (or target hardware)
+# specific file, which is mainly useful for crosscompiling and embedded systems.
+
+include(CMakeLanguageInformation)
+
+# some compilers use different extensions (e.g. sdcc uses .rel)
+# so set the extension here first so it can be overridden by the compiler specific file
+set(CMAKE_OBJC_OUTPUT_EXTENSION .o)
+
+if(NOT CMAKE_INCLUDE_FLAG_OBJC)
+  set(CMAKE_INCLUDE_FLAG_OBJC ${CMAKE_INCLUDE_FLAG_C})
+endif()
+
+set(_INCLUDED_FILE 0)
+
+# Load compiler-specific information.
+if(CMAKE_OBJC_COMPILER_ID)
+  include(Compiler/${CMAKE_OBJC_COMPILER_ID}-OBJC OPTIONAL)
+endif()
+
+set(CMAKE_BASE_NAME)
+get_filename_component(CMAKE_BASE_NAME "${CMAKE_OBJC_COMPILER}" NAME_WE)
+if(CMAKE_COMPILER_IS_GNUOBJC)
+  set(CMAKE_BASE_NAME gcc)
+endif()
+
+
+# load a hardware specific file, mostly useful for embedded compilers
+if(CMAKE_SYSTEM_PROCESSOR)
+  if(CMAKE_OBJC_COMPILER_ID)
+    include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_OBJC_COMPILER_ID}-OBJC-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
+  endif()
+  if (NOT _INCLUDED_FILE)
+    include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_BASE_NAME}-${CMAKE_SYSTEM_PROCESSOR} OPTIONAL)
+  endif ()
+endif()
+
+
+# load the system- and compiler specific files
+if(CMAKE_OBJC_COMPILER_ID)
+  include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_OBJC_COMPILER_ID}-OBJC
+    OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
+endif()
+if (NOT _INCLUDED_FILE)
+  include(Platform/${CMAKE_EFFECTIVE_SYSTEM_NAME}-${CMAKE_BASE_NAME}
+    OPTIONAL RESULT_VARIABLE _INCLUDED_FILE)
+endif ()
+
+# load any compiler-wrapper specific information
+if (CMAKE_OBJC_COMPILER_WRAPPER)
+  __cmake_include_compiler_wrapper(OBJC)
+endif ()
+
+# We specify the compiler information in the system file for some
+# platforms, but this language may not have been enabled when the file
+# was first included.  Include it again to get the language info.
+# Remove this when all compiler info is removed from system files.
+if (NOT _INCLUDED_FILE)
+  include(Platform/${CMAKE_SYSTEM_NAME} OPTIONAL)
+endif ()
+
+if(CMAKE_OBJC_SIZEOF_DATA_PTR)
+  foreach(f ${CMAKE_OBJC_ABI_FILES})
+    include(${f})
+  endforeach()
+  unset(CMAKE_OBJC_ABI_FILES)
+endif()
+
+# This should be included before the _INIT variables are
+# used to initialize the cache.  Since the rule variables
+# have if blocks on them, users can still define them here.
+# But, it should still be after the platform file so changes can
+# be made to those values.
+
+if(CMAKE_USER_MAKE_RULES_OVERRIDE)
+  # Save the full path of the file so try_compile can use it.
+  include(${CMAKE_USER_MAKE_RULES_OVERRIDE} RESULT_VARIABLE _override)
+  set(CMAKE_USER_MAKE_RULES_OVERRIDE "${_override}")
+endif()
+
+if(CMAKE_USER_MAKE_RULES_OVERRIDE_OBJC)
+  # Save the full path of the file so try_compile can use it.
+  include(${CMAKE_USER_MAKE_RULES_OVERRIDE_OBJC} RESULT_VARIABLE _override)
+  set(CMAKE_USER_MAKE_RULES_OVERRIDE_OBJC "${_override}")
+endif()
+
+
+# for most systems a module is the same as a shared library
+# so unless the variable CMAKE_MODULE_EXISTS is set just
+# copy the values from the LIBRARY variables
+if(NOT CMAKE_MODULE_EXISTS)
+  set(CMAKE_SHARED_MODULE_OBJC_FLAGS ${CMAKE_SHARED_LIBRARY_OBJC_FLAGS})
+  set(CMAKE_SHARED_MODULE_CREATE_OBJC_FLAGS ${CMAKE_SHARED_LIBRARY_CREATE_OBJC_FLAGS})
+endif()
+
+set(CMAKE_OBJC_FLAGS_INIT "$ENV{OBJCFLAGS} ${CMAKE_OBJC_FLAGS_INIT}")
+
+cmake_initialize_per_config_variable(CMAKE_OBJC_FLAGS "Flags used by the Objective-C compiler")
+
+if(CMAKE_OBJC_STANDARD_LIBRARIES_INIT)
+  set(CMAKE_OBJC_STANDARD_LIBRARIES "${CMAKE_OBJC_STANDARD_LIBRARIES_INIT}"
+    CACHE STRING "Libraries linked by default with all Objective-C applications.")
+  mark_as_advanced(CMAKE_OBJC_STANDARD_LIBRARIES)
+endif()
+
+include(CMakeCommonLanguageInclude)
+
+# now define the following rule variables
+
+# CMAKE_OBJC_CREATE_SHARED_LIBRARY
+# CMAKE_OBJC_CREATE_SHARED_MODULE
+# CMAKE_OBJC_COMPILE_OBJECT
+# CMAKE_OBJC_LINK_EXECUTABLE
+
+# variables supplied by the generator at use time
+# <TARGET>
+# <TARGET_BASE> the target without the suffix
+# <OBJECTS>
+# <OBJECT>
+# <LINK_LIBRARIES>
+# <FLAGS>
+# <LINK_FLAGS>
+
+# Objective-C compiler information
+# <CMAKE_OBJC_COMPILER>
+# <CMAKE_SHARED_LIBRARY_CREATE_OBJC_FLAGS>
+# <CMAKE_SHARED_MODULE_CREATE_OBJC_FLAGS>
+# <CMAKE_OBJC_LINK_FLAGS>
+
+# Static library tools
+# <CMAKE_AR>
+# <CMAKE_RANLIB>
+
+
+# create an Objective-C shared library
+if(NOT CMAKE_OBJC_CREATE_SHARED_LIBRARY)
+  set(CMAKE_OBJC_CREATE_SHARED_LIBRARY
+      "<CMAKE_OBJC_COMPILER> <CMAKE_SHARED_LIBRARY_OBJC_FLAGS> <LANGUAGE_COMPILE_FLAGS> <LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_OBJC_FLAGS> <SONAME_FLAG><TARGET_SONAME> -o <TARGET> <OBJECTS> <LINK_LIBRARIES>")
+endif()
+
+# create an Objective-C shared module just copy the shared library rule
+if(NOT CMAKE_OBJC_CREATE_SHARED_MODULE)
+  set(CMAKE_OBJC_CREATE_SHARED_MODULE ${CMAKE_OBJC_CREATE_SHARED_LIBRARY})
+endif()
+
+# Create an static archive incrementally for large object file counts.
+# If CMAKE_OBJC_CREATE_STATIC_LIBRARY is set it will override these.
+if(NOT DEFINED CMAKE_OBJC_ARCHIVE_CREATE)
+  set(CMAKE_OBJC_ARCHIVE_CREATE "<CMAKE_AR> qc <TARGET> <LINK_FLAGS> <OBJECTS>")
+endif()
+if(NOT DEFINED CMAKE_OBJC_ARCHIVE_APPEND)
+  set(CMAKE_OBJC_ARCHIVE_APPEND "<CMAKE_AR> q  <TARGET> <LINK_FLAGS> <OBJECTS>")
+endif()
+if(NOT DEFINED CMAKE_OBJC_ARCHIVE_FINISH)
+  set(CMAKE_OBJC_ARCHIVE_FINISH "<CMAKE_RANLIB> <TARGET>")
+endif()
+
+# compile an Objective-C file into an object file
+if(NOT CMAKE_OBJC_COMPILE_OBJECT)
+  set(CMAKE_OBJC_COMPILE_OBJECT
+    "<CMAKE_OBJC_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -o <OBJECT>   -c <SOURCE>")
+endif()
+
+if(NOT CMAKE_OBJC_LINK_EXECUTABLE)
+  set(CMAKE_OBJC_LINK_EXECUTABLE
+    "<CMAKE_OBJC_COMPILER> <FLAGS> <CMAKE_OBJC_LINK_FLAGS> <LINK_FLAGS> <OBJECTS>  -o <TARGET> <LINK_LIBRARIES>")
+endif()
+
+if(NOT CMAKE_EXECUTABLE_RUNTIME_OBJC_FLAG)
+  set(CMAKE_EXECUTABLE_RUNTIME_OBJC_FLAG ${CMAKE_SHARED_LIBRARY_RUNTIME_OBJC_FLAG})
+endif()
+
+if(NOT CMAKE_EXECUTABLE_RUNTIME_OBJC_FLAG_SEP)
+  set(CMAKE_EXECUTABLE_RUNTIME_OBJC_FLAG_SEP ${CMAKE_SHARED_LIBRARY_RUNTIME_OBJC_FLAG_SEP})
+endif()
+
+if(NOT CMAKE_EXECUTABLE_RPATH_LINK_OBJC_FLAG)
+  set(CMAKE_EXECUTABLE_RPATH_LINK_OBJC_FLAG ${CMAKE_SHARED_LIBRARY_RPATH_LINK_OBJC_FLAG})
+endif()
+
+set(CMAKE_OBJC_INFORMATION_LOADED 1)

Modules/CMakeTestOBJCCompiler.cmake

@@ -0,0 +1,94 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+
+if(CMAKE_OBJC_COMPILER_FORCED)
+  # The compiler configuration was forced by the user.
+  # Assume the user has configured all compiler information.
+  set(CMAKE_OBJC_COMPILER_WORKS TRUE)
+  return()
+endif()
+
+include(CMakeTestCompilerCommon)
+
+# work around enforced code signing and / or missing exectuable target type
+set(__CMAKE_SAVED_TRY_COMPILE_TARGET_TYPE ${CMAKE_TRY_COMPILE_TARGET_TYPE})
+if(_CMAKE_FEATURE_DETECTION_TARGET_TYPE)
+  set(CMAKE_TRY_COMPILE_TARGET_TYPE ${_CMAKE_FEATURE_DETECTION_TARGET_TYPE})
+endif()
+
+# Remove any cached result from an older CMake version.
+# We now store this in CMakeCCompiler.cmake.
+unset(CMAKE_OBJC_COMPILER_WORKS CACHE)
+
+# This file is used by EnableLanguage in cmGlobalGenerator to
+# determine that that selected Objective-C compiler can actually compile
+# and link the most basic of programs.   If not, a fatal error
+# is set and cmake stops processing commands and will not generate
+# any makefiles or projects.
+if(NOT CMAKE_OBJC_COMPILER_WORKS)
+  PrintTestCompilerStatus("OBJC" "")
+  __TestCompiler_setTryCompileTargetType()
+  file(WRITE ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testOBJCCompiler.m
+    "#ifdef __cplusplus\n"
+    "# error \"The CMAKE_OBJC_COMPILER is set to a C++ compiler\"\n"
+    "#endif\n"
+    "#ifndef __OBJC__\n"
+    "# error \"The CMAKE_OBJC_COMPILER is not an Objective-C compiler\"\n"
+    "#endif\n"
+    "int main(int argc, char* argv[])\n"
+    "{ (void)argv; return argc-1;}\n")
+  try_compile(CMAKE_OBJC_COMPILER_WORKS ${CMAKE_BINARY_DIR}
+    ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testOBJCCompiler.m
+    OUTPUT_VARIABLE __CMAKE_OBJC_COMPILER_OUTPUT)
+  # Move result from cache to normal variable.
+  set(CMAKE_OBJC_COMPILER_WORKS ${CMAKE_OBJC_COMPILER_WORKS})
+  unset(CMAKE_OBJC_COMPILER_WORKS CACHE)
+  set(OBJC_TEST_WAS_RUN 1)
+  __TestCompiler_restoreTryCompileTargetType()
+endif()
+
+if(NOT CMAKE_OBJC_COMPILER_WORKS)
+  PrintTestCompilerStatus("OBJC" " -- broken")
+  file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+    "Determining if the Objective-C compiler works failed with "
+    "the following output:\n${__CMAKE_OBJC_COMPILER_OUTPUT}\n\n")
+  string(REPLACE "\n" "\n  " _output "${__CMAKE_OBJC_COMPILER_OUTPUT}")
+  message(FATAL_ERROR "The Objective-C compiler\n  \"${CMAKE_OBJC_COMPILER}\"\n"
+    "is not able to compile a simple test program.\nIt fails "
+    "with the following output:\n  ${_output}\n\n"
+    "CMake will not be able to correctly generate this project.")
+else()
+  if(OBJC_TEST_WAS_RUN)
+    PrintTestCompilerStatus("OBJC" " -- works")
+    file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+      "Determining if the Objective-C compiler works passed with "
+      "the following output:\n${__CMAKE_OBJC_COMPILER_OUTPUT}\n\n")
+  endif()
+
+  # Try to identify the ABI and configure it into CMakeOBJCCompiler.cmake
+  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompilerABI.cmake)
+  CMAKE_DETERMINE_COMPILER_ABI(OBJC ${CMAKE_ROOT}/Modules/CMakeOBJCCompilerABI.m)
+  # Try to identify the compiler features
+  include(${CMAKE_ROOT}/Modules/CMakeDetermineCompileFeatures.cmake)
+  CMAKE_DETERMINE_COMPILE_FEATURES(OBJC)
+
+  # Re-configure to save learned information.
+  configure_file(
+    ${CMAKE_ROOT}/Modules/CMakeOBJCCompiler.cmake.in
+    ${CMAKE_PLATFORM_INFO_DIR}/CMakeOBJCCompiler.cmake
+    @ONLY
+    )
+  include(${CMAKE_PLATFORM_INFO_DIR}/CMakeOBJCCompiler.cmake)
+
+  if(CMAKE_OBJC_SIZEOF_DATA_PTR)
+    foreach(f ${CMAKE_OBJC_ABI_FILES})
+      include(${f})
+    endforeach()
+    unset(CMAKE_OBJC_ABI_FILES)
+  endif()
+endif()
+
+set(CMAKE_TRY_COMPILE_TARGET_TYPE ${__CMAKE_SAVED_TRY_COMPILE_TARGET_TYPE})
+unset(__CMAKE_SAVED_TRY_COMPILE_TARGET_TYPE)
+unset(__CMAKE_OBJC_COMPILER_OUTPUT)

Modules/CheckOBJCCompilerFlag.cmake

@@ -0,0 +1,64 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+CheckOBJCCompilerFlag
+---------------------
+
+Check whether the Objective-C compiler supports a given flag.
+
+.. command:: check_objc_compiler_flag
+
+  .. code-block:: cmake
+
+    check_objc_compiler_flag(<flag> <var>)
+
+  Check that the ``<flag>`` is accepted by the compiler without
+  a diagnostic.  Stores the result in an internal cache entry
+  named ``<var>``.
+
+This command temporarily sets the ``CMAKE_REQUIRED_DEFINITIONS`` variable
+and calls the ``check_objc_source_compiles`` macro from the
+:module:`CheckOBJCSourceCompiles` module.  See documentation of that
+module for a listing of variables that can otherwise modify the build.
+
+A positive result from this check indicates only that the compiler did not
+issue a diagnostic message when given the flag.  Whether the flag has any
+effect or even a specific one is beyond the scope of this module.
+
+.. note::
+  Since the :command:`try_compile` command forwards flags from variables
+  like :variable:`CMAKE_OBJC_FLAGS <CMAKE_<LANG>_FLAGS>`, unknown flags
+  in such variables may cause a false negative for this check.
+#]=======================================================================]
+
+include_guard(GLOBAL)
+include(CheckOBJCSourceCompiles)
+include(CMakeCheckCompilerFlagCommonPatterns)
+
+macro (CHECK_OBJC_COMPILER_FLAG _FLAG _RESULT)
+  set(SAFE_CMAKE_REQUIRED_DEFINITIONS "${CMAKE_REQUIRED_DEFINITIONS}")
+  set(CMAKE_REQUIRED_DEFINITIONS "${_FLAG}")
+
+   # Normalize locale during test compilation.
+  set(_CheckOBJCCompilerFlag_LOCALE_VARS LC_ALL LC_MESSAGES LANG)
+  foreach(v ${_CheckOBJCCompilerFlag_LOCALE_VARS})
+    set(_CheckOBJCCompilerFlag_SAVED_${v} "$ENV{${v}}")
+    set(ENV{${v}} OBJC)
+  endforeach()
+  CHECK_COMPILER_FLAG_COMMON_PATTERNS(_CheckOBJCCompilerFlag_COMMON_PATTERNS)
+  CHECK_OBJC_SOURCE_COMPILES("#ifndef __OBJC__\n#  error \"Not an Objective-C compiler\"\n#endif\nint main(void) { return 0; }" ${_RESULT}
+    # Some compilers do not fail with a bad flag
+    FAIL_REGEX "command line option .* is valid for .* but not for Objective-C" # GNU
+    FAIL_REGEX "argument unused during compilation: .*" # Clang
+    ${_CheckOBJCCompilerFlag_COMMON_PATTERNS}
+    )
+  foreach(v ${_CheckOBJCCompilerFlag_LOCALE_VARS})
+    set(ENV{${v}} ${_CheckOBJCCompilerFlag_SAVED_${v}})
+    unset(_CheckOBJCCompilerFlag_SAVED_${v})
+  endforeach()
+  unset(_CheckOBJCCompilerFlag_LOCALE_VARS)
+  unset(_CheckOBJCCompilerFlag_COMMON_PATTERNS)
+
+  set (CMAKE_REQUIRED_DEFINITIONS "${SAFE_CMAKE_REQUIRED_DEFINITIONS}")
+endmacro ()

Modules/CheckOBJCSourceCompiles.cmake

@@ -0,0 +1,145 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+CheckOBJCSourceCompiles
+-----------------------
+
+Check if given Objective-C source compiles and links into an executable.
+
+.. command:: check_objc_source_compiles
+
+  .. code-block:: cmake
+
+    check_objc_source_compiles(<code> <resultVar>
+                               [FAIL_REGEX <regex1> [<regex2>...]])
+
+  Check that the source supplied in ``<code>`` can be compiled as a Objectie-C source
+  file and linked as an executable (so it must contain at least a ``main()``
+  function). The result will be stored in the internal cache variable specified
+  by ``<resultVar>``, with a boolean true value for success and boolean false
+  for failure. If ``FAIL_REGEX`` is provided, then failure is determined by
+  checking if anything in the output matches any of the specified regular
+  expressions.
+
+  The underlying check is performed by the :command:`try_compile` command. The
+  compile and link commands can be influenced by setting any of the following
+  variables prior to calling ``check_objc_source_compiles()``:
+
+  ``CMAKE_REQUIRED_FLAGS``
+    Additional flags to pass to the compiler. Note that the contents of
+    :variable:`CMAKE_OBJC_FLAGS <CMAKE_<LANG>_FLAGS>` and its associated
+    configuration-specific variable are automatically added to the compiler
+    command before the contents of ``CMAKE_REQUIRED_FLAGS``.
+
+  ``CMAKE_REQUIRED_DEFINITIONS``
+    A :ref:`;-list <CMake Language Lists>` of compiler definitions of the form
+    ``-DFOO`` or ``-DFOO=bar``. A definition for the name specified by
+    ``<resultVar>`` will also be added automatically.
+
+  ``CMAKE_REQUIRED_INCLUDES``
+    A :ref:`;-list <CMake Language Lists>` of header search paths to pass to
+    the compiler. These will be the only header search paths used by
+    ``try_compile()``, i.e. the contents of the :prop_dir:`INCLUDE_DIRECTORIES`
+    directory property will be ignored.
+
+  ``CMAKE_REQUIRED_LINK_OPTIONS``
+    A :ref:`;-list <CMake Language Lists>` of options to add to the link
+    command (see :command:`try_compile` for further details).
+
+  ``CMAKE_REQUIRED_LIBRARIES``
+    A :ref:`;-list <CMake Language Lists>` of libraries to add to the link
+    command. These can be the name of system libraries or they can be
+    :ref:`Imported Targets <Imported Targets>` (see :command:`try_compile` for
+    further details).
+
+  ``CMAKE_REQUIRED_QUIET``
+    If this variable evaluates to a boolean true value, all status messages
+    associated with the check will be suppressed.
+
+  The check is only performed once, with the result cached in the variable
+  named by ``<resultVar>``. Every subsequent CMake run will re-use this cached
+  value rather than performing the check again, even if the ``<code>`` changes.
+  In order to force the check to be re-evaluated, the variable named by
+  ``<resultVar>`` must be manually removed from the cache.
+
+#]=======================================================================]
+
+include_guard(GLOBAL)
+
+macro(CHECK_OBJC_SOURCE_COMPILES SOURCE VAR)
+  if(NOT DEFINED "${VAR}")
+    set(_FAIL_REGEX)
+    set(_key)
+    foreach(arg ${ARGN})
+      if("${arg}" MATCHES "^(FAIL_REGEX)$")
+        set(_key "${arg}")
+      elseif(_key)
+        list(APPEND _${_key} "${arg}")
+      else()
+        message(FATAL_ERROR "Unknown argument:\n  ${arg}\n")
+      endif()
+    endforeach()
+    set(MACRO_CHECK_FUNCTION_DEFINITIONS
+      "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
+    if(CMAKE_REQUIRED_LINK_OPTIONS)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS
+        LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS})
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS)
+    endif()
+    if(CMAKE_REQUIRED_LIBRARIES)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES
+        LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES)
+    endif()
+    if(CMAKE_REQUIRED_INCLUDES)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES
+        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES)
+    endif()
+    file(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.m"
+      "${SOURCE}\n")
+
+    if(NOT CMAKE_REQUIRED_QUIET)
+      message(STATUS "Performing Test ${VAR}")
+    endif()
+    try_compile(${VAR}
+      ${CMAKE_BINARY_DIR}
+      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.m
+      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      ${CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS}
+      ${CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES}
+      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
+      "${CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES}"
+      OUTPUT_VARIABLE OUTPUT)
+
+    foreach(_regex ${_FAIL_REGEX})
+      if("${OUTPUT}" MATCHES "${_regex}")
+        set(${VAR} 0)
+      endif()
+    endforeach()
+
+    if(${VAR})
+      set(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
+      if(NOT CMAKE_REQUIRED_QUIET)
+        message(STATUS "Performing Test ${VAR} - Success")
+      endif()
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Performing Objective-C SOURCE FILE Test ${VAR} succeeded with the following output:\n"
+        "${OUTPUT}\n"
+        "Source file was:\n${SOURCE}\n")
+    else()
+      if(NOT CMAKE_REQUIRED_QUIET)
+        message(STATUS "Performing Test ${VAR} - Failed")
+      endif()
+      set(${VAR} "" CACHE INTERNAL "Test ${VAR}")
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Performing Objective-C SOURCE FILE Test ${VAR} failed with the following output:\n"
+        "${OUTPUT}\n"
+        "Source file was:\n${SOURCE}\n")
+    endif()
+  endif()
+endmacro()

Modules/CheckOBJCSourceRuns.cmake

@@ -0,0 +1,145 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+CheckOBJCSourceRuns
+-------------------
+
+Check if given Objective-C source compiles and links into an executable and can
+subsequently be run.
+
+.. command:: check_objc_source_runs
+
+  .. code-block:: cmake
+
+    check_objc_source_runs(<code> <resultVar>)
+
+  Check that the source supplied in ``<code>`` can be compiled as a Objective-C source
+  file, linked as an executable and then run. The ``<code>`` must contain at
+  least a ``main()`` function. If the ``<code>`` could be built and run
+  successfully, the internal cache variable specified by ``<resultVar>`` will
+  be set to 1, otherwise it will be set to an value that evaluates to boolean
+  false (e.g. an empty string or an error message).
+
+  The underlying check is performed by the :command:`try_run` command. The
+  compile and link commands can be influenced by setting any of the following
+  variables prior to calling ``check_objc_source_runs()``:
+
+  ``CMAKE_REQUIRED_FLAGS``
+    Additional flags to pass to the compiler. Note that the contents of
+    :variable:`CMAKE_OBJC_FLAGS <CMAKE_<LANG>_FLAGS>` and its associated
+    configuration-specific variable are automatically added to the compiler
+    command before the contents of ``CMAKE_REQUIRED_FLAGS``.
+
+  ``CMAKE_REQUIRED_DEFINITIONS``
+    A :ref:`;-list <CMake Language Lists>` of compiler definitions of the form
+    ``-DFOO`` or ``-DFOO=bar``. A definition for the name specified by
+    ``<resultVar>`` will also be added automatically.
+
+  ``CMAKE_REQUIRED_INCLUDES``
+    A :ref:`;-list <CMake Language Lists>` of header search paths to pass to
+    the compiler. These will be the only header search paths used by
+    ``try_run()``, i.e. the contents of the :prop_dir:`INCLUDE_DIRECTORIES`
+    directory property will be ignored.
+
+  ``CMAKE_REQUIRED_LINK_OPTIONS``
+    A :ref:`;-list <CMake Language Lists>` of options to add to the link
+    command (see :command:`try_run` for further details).
+
+  ``CMAKE_REQUIRED_LIBRARIES``
+    A :ref:`;-list <CMake Language Lists>` of libraries to add to the link
+    command. These can be the name of system libraries or they can be
+    :ref:`Imported Targets <Imported Targets>` (see :command:`try_run` for
+    further details).
+
+  ``CMAKE_REQUIRED_QUIET``
+    If this variable evaluates to a boolean true value, all status messages
+    associated with the check will be suppressed.
+
+  The check is only performed once, with the result cached in the variable
+  named by ``<resultVar>``. Every subsequent CMake run will re-use this cached
+  value rather than performing the check again, even if the ``<code>`` changes.
+  In order to force the check to be re-evaluated, the variable named by
+  ``<resultVar>`` must be manually removed from the cache.
+
+#]=======================================================================]
+
+include_guard(GLOBAL)
+
+macro(CHECK_OBJC_SOURCE_RUNS SOURCE VAR)
+  if(NOT DEFINED "${VAR}")
+    set(MACRO_CHECK_FUNCTION_DEFINITIONS
+      "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
+    if(CMAKE_REQUIRED_LINK_OPTIONS)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS
+        LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS})
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS)
+    endif()
+    if(CMAKE_REQUIRED_LIBRARIES)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES
+        LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES)
+    endif()
+    if(CMAKE_REQUIRED_INCLUDES)
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES
+        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
+    else()
+      set(CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES)
+    endif()
+    file(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.m"
+      "${SOURCE}\n")
+
+    if(NOT CMAKE_REQUIRED_QUIET)
+      message(STATUS "Performing Test ${VAR}")
+    endif()
+    try_run(${VAR}_EXITCODE ${VAR}_COMPILED
+      ${CMAKE_BINARY_DIR}
+      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.m
+      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
+      ${CHECK_OBJC_SOURCE_COMPILES_ADD_LINK_OPTIONS}
+      ${CHECK_OBJC_SOURCE_COMPILES_ADD_LIBRARIES}
+      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
+      -DCMAKE_SKIP_RPATH:BOOL=${CMAKE_SKIP_RPATH}
+      "${CHECK_OBJC_SOURCE_COMPILES_ADD_INCLUDES}"
+      COMPILE_OUTPUT_VARIABLE OUTPUT
+      RUN_OUTPUT_VARIABLE RUN_OUTPUT)
+    # if it did not compile make the return value fail code of 1
+    if(NOT ${VAR}_COMPILED)
+      set(${VAR}_EXITCODE 1)
+    endif()
+    # if the return value was 0 then it worked
+    if("${${VAR}_EXITCODE}" EQUAL 0)
+      set(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
+      if(NOT CMAKE_REQUIRED_QUIET)
+        message(STATUS "Performing Test ${VAR} - Success")
+      endif()
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Performing Objective-C SOURCE FILE Test ${VAR} succeeded with the following compile output:\n"
+        "${OUTPUT}\n"
+        "...and run output:\n"
+        "${RUN_OUTPUT}\n"
+        "Return value: ${${VAR}}\n"
+        "Source file was:\n${SOURCE}\n")
+    else()
+      if(CMAKE_CROSSCOMPILING AND "${${VAR}_EXITCODE}" MATCHES  "FAILED_TO_RUN")
+        set(${VAR} "${${VAR}_EXITCODE}")
+      else()
+        set(${VAR} "" CACHE INTERNAL "Test ${VAR}")
+      endif()
+
+      if(NOT CMAKE_REQUIRED_QUIET)
+        message(STATUS "Performing Test ${VAR} - Failed")
+      endif()
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Performing Objective-C SOURCE FILE Test ${VAR} failed with the following compile output:\n"
+        "${OUTPUT}\n"
+        "...and run output:\n"
+        "${RUN_OUTPUT}\n"
+        "Return value: ${${VAR}_EXITCODE}\n"
+        "Source file was:\n${SOURCE}\n")
+
+    endif()
+  endif()
+endmacro()

Modules/Compiler/AppleClang-OBJC.cmake

@@ -0,0 +1,17 @@
+include(Compiler/Clang-OBJC)
+
+if(NOT CMAKE_OBJC_COMPILER_VERSION VERSION_LESS 4.0)
+  set(CMAKE_OBJC90_STANDARD_COMPILE_OPTION "-std=c90")
+  set(CMAKE_OBJC90_EXTENSION_COMPILE_OPTION "-std=gnu90")
+  set(CMAKE_OBJC90_STANDARD__HAS_FULL_SUPPORT ON)
+
+  set(CMAKE_OBJC99_STANDARD_COMPILE_OPTION "-std=c99")
+  set(CMAKE_OBJC99_EXTENSION_COMPILE_OPTION "-std=gnu99")
+  set(CMAKE_OBJC99_STANDARD__HAS_FULL_SUPPORT ON)
+
+  set(CMAKE_OBJC11_STANDARD_COMPILE_OPTION "-std=c11")
+  set(CMAKE_OBJC11_EXTENSION_COMPILE_OPTION "-std=gnu11")
+  set(CMAKE_OBJC11_STANDARD__HAS_FULL_SUPPORT ON)
+endif()
+
+__compiler_check_default_language_standard(OBJC 4.0 99)

Modules/Compiler/Clang-OBJC.cmake

@@ -0,0 +1,18 @@
+include(Compiler/Clang)
+__compiler_clang(OBJC)
+
+if(NOT CMAKE_OBJC_COMPILER_VERSION VERSION_LESS 3.4)
+  set(CMAKE_OBJC90_STANDARD_COMPILE_OPTION "-std=c90")
+  set(CMAKE_OBJC90_EXTENSION_COMPILE_OPTION "-std=gnu90")
+  set(CMAKE_OBJC90_STANDARD__HAS_FULL_SUPPORT ON)
+
+  set(CMAKE_OBJC99_STANDARD_COMPILE_OPTION "-std=c99")
+  set(CMAKE_OBJC99_EXTENSION_COMPILE_OPTION "-std=gnu99")
+  set(CMAKE_OBJC99_STANDARD__HAS_FULL_SUPPORT ON)
+
+  set(CMAKE_OBJC11_STANDARD_COMPILE_OPTION "-std=c11")
+  set(CMAKE_OBJC11_EXTENSION_COMPILE_OPTION "-std=gnu11")
+  set(CMAKE_OBJC11_STANDARD__HAS_FULL_SUPPORT ON)
+endif()
+
+__compiler_check_default_language_standard(OBJC 3.4 99 3.6 11)

Modules/Compiler/GNU-OBJC.cmake

@@ -0,0 +1,6 @@
+include(Compiler/GNU)
+__compiler_gnu(OBJC)
+
+if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.2)
+  set(CMAKE_CXX_COMPILE_OPTIONS_VISIBILITY_INLINES_HIDDEN "-fvisibility-inlines-hidden")
+endif()

Modules/Platform/Apple-AppleClang-OBJC.cmake

@@ -0,0 +1,6 @@
+include(Platform/Apple-Clang-OBJC)
+if(NOT CMAKE_OBJC_COMPILER_VERSION VERSION_LESS 4.2)
+  set(CMAKE_OBJC_SYSTEM_FRAMEWORK_SEARCH_FLAG "-iframework ")
+else()
+  unset(CMAKE_OBJC_SYSTEM_FRAMEWORK_SEARCH_FLAG)
+endif()

Modules/Platform/Apple-Clang-OBJC.cmake

@@ -0,0 +1,2 @@
+include(Platform/Apple-Clang)
+__apple_compiler_clang(OBJC)

Modules/Platform/Apple-GNU-OBJC.cmake

@@ -0,0 +1,4 @@
+include(Platform/Apple-GNU)
+__apple_compiler_gnu(OBJC)
+cmake_gnu_set_sysroot_flag(OBJC)
+cmake_gnu_set_osx_deployment_target_flag(OBJC)

Modules/Platform/Darwin.cmake

@@ -119,10 +119,15 @@ set(CMAKE_C_CREATE_MACOSX_FRAMEWORK
 set(CMAKE_CXX_CREATE_MACOSX_FRAMEWORK
       "<CMAKE_CXX_COMPILER> <LANGUAGE_COMPILE_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS> <LINK_FLAGS> -o <TARGET> <SONAME_FLAG> <TARGET_INSTALLNAME_DIR><TARGET_SONAME> <OBJECTS> <LINK_LIBRARIES>")
 
+set(CMAKE_OBJC_CREATE_MACOSX_FRAMEWORK
+  "<CMAKE_OBJC_COMPILER> <LANGUAGE_COMPILE_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_OBJC_FLAGS> <LINK_FLAGS> -o <TARGET> -dynamiclib -install_name <TARGET_INSTALLNAME_DIR><TARGET_SONAME> <OBJECTS> <LINK_LIBRARIES>"
+)
+
 # Set default framework search path flag for languages known to use a
 # preprocessor that may find headers in frameworks.
 set(CMAKE_C_FRAMEWORK_SEARCH_FLAG -F)
 set(CMAKE_CXX_FRAMEWORK_SEARCH_FLAG -F)
+set(CMAKE_OBJC_FRAMEWORK_SEARCH_FLAG -F)
 set(CMAKE_Fortran_FRAMEWORK_SEARCH_FLAG -F)
 
 # default to searching for frameworks first
@@ -222,7 +227,7 @@ unset(_apps_paths)
 include(Platform/UnixPaths)
 if(_CMAKE_OSX_SYSROOT_PATH AND EXISTS ${_CMAKE_OSX_SYSROOT_PATH}/usr/include)
   list(APPEND CMAKE_SYSTEM_PREFIX_PATH ${_CMAKE_OSX_SYSROOT_PATH}/usr)
-  foreach(lang C CXX)
+  foreach(lang C CXX OBJC)
     list(APPEND _CMAKE_${lang}_IMPLICIT_INCLUDE_DIRECTORIES_INIT ${_CMAKE_OSX_SYSROOT_PATH}/usr/include)
   endforeach()
 endif()

Source/cmLocalGenerator.cxx

@@ -1654,7 +1654,7 @@ void cmLocalGenerator::AddArchitectureFlags(std::string& flags,
     const char* deploymentTargetFlag =
       this->Makefile->GetDefinition(deploymentTargetFlagVar);
     if (!archs.empty() && !lang.empty() &&
-        (lang[0] == 'C' || lang[0] == 'F')) {
+        (lang[0] == 'C' || lang[0] == 'F' || lang[0] == 'O')) {
       for (std::string const& arch : archs) {
         flags += " -arch ";
         flags += arch;

Tests/CMakeLists.txt

@@ -2328,6 +2328,43 @@ ${CMake_SOURCE_DIR}/Utilities/Release/push.bash --dir dev -- '${CMake_BUILD_NIGH
       list(APPEND TEST_BUILD_DIRS "${CMake_BINARY_DIR}/Tests/CFBundleTest")
 
       ADD_TEST_MACRO(ObjC++ ObjC++)
+
+      add_test(Objective-C.simple-build-test ${CMAKE_CTEST_COMMAND}
+        --build-and-test
+        "${CMake_SOURCE_DIR}/Tests/Objective-C/simple-build-test"
+        "${CMake_BINARY_DIR}/Tests/Objective-C/simple-build-test"
+        --build-two-config
+        ${build_generator_args}
+        --build-project simple-build-test
+        --build-options ${build_options}
+        --test-command simple-build-test
+      )
+      list(APPEND TEST_BUILD_DIRS "${CMake_BINARY_DIR}/Tests/Objective-C/simple-build-test")
+
+      add_test(Objective-C.c-file-extension-test ${CMAKE_CTEST_COMMAND}
+        --build-and-test
+        "${CMake_SOURCE_DIR}/Tests/Objective-C/c-file-extension-test"
+        "${CMake_BINARY_DIR}/Tests/Objective-C/c-file-extension-test"
+        --build-two-config
+        ${build_generator_args}
+        --build-project c-file-extension-test
+        --build-options ${build_options}
+        --test-command c-file-extension-test
+      )
+      list(APPEND TEST_BUILD_DIRS "${CMake_BINARY_DIR}/Tests/Objective-C/c-file-extension-test")
+
+      add_test(Objective-C.objc-file-extension-test ${CMAKE_CTEST_COMMAND}
+        --build-and-test
+        "${CMake_SOURCE_DIR}/Tests/Objective-C/objc-file-extension-test"
+        "${CMake_BINARY_DIR}/Tests/Objective-C/objc-file-extension-test"
+        --build-two-config
+        ${build_generator_args}
+        --build-project objc-file-extension-test
+        --build-options ${build_options}
+        --test-command objc-file-extension-test
+      )
+      list(APPEND TEST_BUILD_DIRS "${CMAKE_BINARY_DIR}/Tests/Objective-C/objc-file-extension-test")
+
     endif ()
   endif ()
 

Tests/CMakeOnly/CMakeLists.txt

@@ -30,6 +30,12 @@ add_CMakeOnly_test(CheckStructHasMember)
 
 add_CMakeOnly_test(CompilerIdC)
 add_CMakeOnly_test(CompilerIdCXX)
+
+if(CMAKE_OBJC_COMPILER)
+  add_CMakeOnly_test(CompilerIdOBJC)
+  add_CMakeOnly_test(CheckOBJCCompilerFlag)
+endif()
+
 if(CMAKE_Fortran_COMPILER)
   add_CMakeOnly_test(CompilerIdFortran)
 endif()

Tests/CMakeOnly/CheckLanguage/CMakeLists.txt

@@ -5,10 +5,19 @@ include(CheckLanguage)
 set(langs )
 set(expect_C 1)
 set(expect_CXX 1)
+if(APPLE)
+  set(expect_OBJC 1)
+endif()
 unset(expect_Fortran)
 set(expect_NoSuchLanguage 0)
 
-foreach(lang C CXX Fortran CUDA NoSuchLanguage)
+set(LANGUAGES C CXX Fortran CUDA NoSuchLanguage)
+
+if(APPLE)
+  list(APPEND LANGUAGES OBJC)
+endif()
+
+foreach(lang ${LANGUAGES})
   check_language(${lang})
   if(NOT DEFINED CMAKE_${lang}_COMPILER)
     message(FATAL_ERROR "check_language(${lang}) did not set result")

Tests/CMakeOnly/CheckOBJCCompilerFlag/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 2.8.12)
+
+project(CheckOBJCCompilerFlag)
+
+include(CheckOBJCCompilerFlag)
+
+if(CMAKE_COMPILER_IS_GNUOBJC)
+  set(COMPILER_FLAG -fobjc-direct-dispatch)
+else()
+  set(COMPILER_FLAG -fobjc-gc)
+endif()
+
+CHECK_OBJC_COMPILER_FLAGS(${COMPILER_FLAG} HAS_COMPILER_FLAG)
+
+if(NOT HAS_COMPILER_FLAG)
+  message(SEND_ERROR "Test fail: HAS_COMPILER_FLAG: ${COMPILER_FLAG}")
+endif

Tests/CMakeOnly/CompilerIdOBJC/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 2.8.12)
+project(CompilerIdOBJC OBJC)
+
+foreach(v
+    CMAKE_OBJC_COMPILER
+    CMAKE_OBJC_COMPILER_ID
+    CMAKE_OBJC_COMPILER_VERSION
+    )
+  if(${v})
+    message(STATUS "${v}=[${${v}}]")
+  else()
+    message(SEND_ERROR "${v} not set!")
+  endif()
+endforeach()

Tests/Objective-C/c-file-extension-test/CMakeLists.txt

@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.15)
+
+project(c-file-extension-test C)
+
+add_executable(c-file-extension-test main.m)

Tests/Objective-C/c-file-extension-test/main.m

@@ -0,0 +1,8 @@
+#ifndef __OBJC__
+#  error "Compiler cannot compile Objective-C"
+#endif
+
+int main()
+{
+  return 0;
+}

Tests/Objective-C/objc-file-extension-test/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.15)
+
+project(objc-file-extension-test OBJC CXX)
+
+add_executable(objc-file-extension-test main.m)
+target_link_libraries(objc-file-extension-test "-framework Foundation")

Tests/Objective-C/objc-file-extension-test/main.m

@@ -0,0 +1,12 @@
+#ifndef __OBJC__
+#  error "Compiler is not an Objective-C compiler."
+#endif
+
+#import <Foundation/Foundation.h>
+
+int main()
+{
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+  [pool release];
+  return 0;
+}

Tests/Objective-C/simple-build-test/CMakeLists.txt

@@ -0,0 +1,11 @@
+cmake_minimum_required(VERSION 3.15)
+
+set(CMAKE_MACOSX_RPATH OFF)
+
+project(simple-build-test OBJC)
+
+add_library(foo SHARED foo.m)
+target_link_libraries(foo "-framework Foundation")
+
+add_executable(simple-build-test main.m)
+target_link_libraries(simple-build-test "-framework Foundation" foo)

Tests/Objective-C/simple-build-test/foo.h

@@ -0,0 +1,9 @@
+#import <Foundation/Foundation.h>
+
+@interface Foo : NSObject {
+  NSNumber* age;
+}
+
+@property (nonatomic, retain) NSNumber* age;
+
+@end

Tests/Objective-C/simple-build-test/foo.m

@@ -0,0 +1,7 @@
+#import "foo.h"
+
+@implementation Foo
+
+@synthesize age;
+
+@end

Tests/Objective-C/simple-build-test/main.m

@@ -0,0 +1,12 @@
+#import <Foundation/Foundation.h>
+#import "foo.h"
+
+int main(int argc, char **argv)
+{
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+  Foo *theFoo = [[Foo alloc] init];
+  theFoo.age = [NSNumber numberWithInt:argc];
+  NSLog(@"%d\n",[theFoo.age intValue]);
+  [pool release];
+  return 0;
+}

Tests/TryCompile/CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required (VERSION 2.6)
-project(TryCompile)
+project(TryCompile OBJC C CXX)
 
 macro(TEST_ASSERT value msg)
   if (NOT ${value})
@@ -313,6 +313,34 @@ if(CMAKE_C_COMPILER_ID STREQUAL "GNU")
   TEST_ASSERT(C_STRICT_PROTOTYPES "CHECK_C_COMPILER_FLAG failed -Werror -Wstrict-prototypes")
 endif()
 
+#########################################################################
+#
+# Test that the CHECK_OBJCC_SOURCE_COMPILES, CHECK_OBJC_SOURCE_RUNS
+# macros work.
+
+include(CheckOBJCSourceCompiles)
+include(CheckOBJCSourceRuns)
+
+CHECK_OBJC_SOURCE_COMPILES("I don't build in Objective-C" OBJC_BUILD_SHOULD_FAIL)
+CHECK_OBJC_SOURCE_COMPILES("int main() { return 0; }" SIMPLE_OBJC_BUILD_SHOULD_WORK)
+
+TEST_FAIL(OBJC_BUILD_SHOULD_FAIL "CHECK_OBJC_SOURCE_COMPILES() succeeded, but should have failed")
+TEST_ASSERT(SIMPLE_OBJC_BUILD_SHOULD_WORK "CHECK_OBJC_SOURCE_COMPILES() failed, but should have succeeded")
+
+set(CMAKE_REQUIRED_LIBRARIES "-framework Foundation")
+
+CHECK_OBJC_SOURCE_COMPILES("#import <Foundation/Foundation.h>\nint main()\n{\nNSObject *foo;\nreturn 0;\n}\n" OBJC_BUILD_SHOULD_WORK)
+CHECK_OBJC_SOURCE_RUNS("int main() { return 2; }" SIMPLE_OBJC_RUN_SHOULD_FAIL)
+CHECK_OBJC_SOURCE_RUNS("int main() { return 0; }" SIMPLE_OBJC_RUN_SHOULD_WORK)
+CHECK_OBJC_SOURCE_RUNS("#import <Foundation/Foundation.h>\nint main()\n{\nNSObject *foo;\nreturn 2;\n}\n" OBJC_RUN_SHOULD_FAIL)
+CHECK_OBJC_SOURCE_RUNS("#import <Foundation/Foundation.h>\nint main()\n{\nNSObject *foo;\nreturn 0;\n}\n" OBJC_RUN_SHOULD_WORK)
+
+TEST_ASSERT(OBJC_BUILD_SHOULD_WORK "CHECK_OBJC_SOURCE_COMPILES() failed, but should have succeeded")
+TEST_FAIL(SIMPLE_OBJC_RUN_SHOULD_FAIL "CHECK_OBJC_SOURC_RUNS() succeeds, but should have failed")
+TEST_ASSERT(SIMPLE_OBJC_RUN_SHOULD_WORK "CHECK_OBJC_SOURCE_RUNS() failed, but should have succeeded")
+TEST_FAIL(OBJC_RUN_SHOULD_FAIL "CHECK_OBJC_SOURCE_RUNS() succeeds, but should have failed")
+TEST_ASSERT(OBJC_RUN_SHOULD_WORK "CHECK_OBJC_SOURCE_RUNS() failed, but should have succeeded")
+
 #######################################################################
 #
 # also test that the check_prototype_definition macro works