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 <cristian.adam@gmail.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/Modules/CMakeOBJCCompiler.cmake.in b/Modules/CMakeOBJCCompiler.cmake.in
new file mode 100644
index 0000000000..155551789f
--- /dev/null
+++ b/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@")