CMake/Modules/CheckOBJCSourceCompiles.cmake

# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file LICENSE.rst or https://cmake.org/licensing for details.

#[=======================================================================[.rst:
CheckOBJCSourceCompiles
-----------------------

.. versionadded:: 3.16

This module provides a command to check whether an Objective-C source can
be built.

Load this module in a CMake project with:

.. code-block:: cmake

  include(CheckOBJCSourceCompiles)

Commands
^^^^^^^^

This module provides the following command:

.. command:: check_objc_source_compiles

  Checks once whether the given Objective-C source code can be built:

  .. code-block:: cmake

    check_objc_source_compiles(<code> <variable> [FAIL_REGEX <regexes>...])

  This command checks once that the source supplied in ``<code>`` can be
  compiled (and linked into an executable).  The result of the check is
  stored in the internal cache variable specified by ``<variable>``.

  The arguments are:

  ``<code>``
    Source code to check.  This must be an entire program, as written in a
    file containing the body block.  All symbols used in the source code
    are expected to be declared as usual in their corresponding headers.

  ``<variable>``
    Variable name of an internal cache variable to store the result of the
    check, with boolean true for success and boolean false for failure.

  ``FAIL_REGEX <regexes>...``
    If this option is provided with one or more regular expressions, then
    failure is determined by checking if anything in the compiler output
    matches any of the specified regular expressions.

  .. rubric:: Variables Affecting the Check

  The following variables may be set before calling this command to modify
  the way the check is run:

  .. include:: /module/include/CMAKE_REQUIRED_FLAGS.rst

  .. include:: /module/include/CMAKE_REQUIRED_DEFINITIONS.rst

  .. include:: /module/include/CMAKE_REQUIRED_INCLUDES.rst

  .. include:: /module/include/CMAKE_REQUIRED_LINK_OPTIONS.rst

  .. include:: /module/include/CMAKE_REQUIRED_LIBRARIES.rst

  .. include:: /module/include/CMAKE_REQUIRED_LINK_DIRECTORIES.rst

  .. include:: /module/include/CMAKE_REQUIRED_QUIET.rst

  .. include:: /module/include/CMAKE_TRY_COMPILE_TARGET_TYPE.rst

Examples
^^^^^^^^

In the following example, this module is used to check whether the provided
Objective-C source code compiles and links.  Result of the check is stored in
the internal cache variable ``HAVE_WORKING_CODE``.

.. code-block:: cmake

  include(CheckOBJCSourceCompiles)

  check_objc_source_compiles("
    #import <Foundation/Foundation.h>
    int main()
    {
      NSObject *foo;
      return 0;
    }
  " HAVE_WORKING_CODE)

See Also
^^^^^^^^

* The :module:`CheckSourceCompiles` module for a more general command to
  check whether source can be built.
* The :module:`CheckSourceRuns` module to check whether source can be built
  and run.
#]=======================================================================]

include_guard(GLOBAL)
include(Internal/CheckSourceCompiles)

macro(CHECK_OBJC_SOURCE_COMPILES SOURCE VAR)
  cmake_check_source_compiles(OBJC "${SOURCE}" ${VAR} ${ARGN})
endmacro()