CheckCXXSourceRuns.cmake 5.79 KB
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# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
# file Copyright.txt or https://cmake.org/licensing for details.

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#[=======================================================================[.rst:
CheckCXXSourceRuns
------------------

Check if given C++ source compiles and links into an executable and can
subsequently be run.

.. command:: check_cxx_source_runs

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  .. code-block:: cmake
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    check_cxx_source_runs(<code> <resultVar>)
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  Check that the source supplied in ``<code>`` can be compiled as a 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).
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  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_cxx_source_runs()``:

  ``CMAKE_REQUIRED_FLAGS``
    Additional flags to pass to the compiler. Note that the contents of
    :variable:`CMAKE_CXX_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
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    ``<resultVar>`` will also be added automatically.
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  ``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.

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  ``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).

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  ``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
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  named by ``<resultVar>``. Every subsequent CMake run will re-use this cached
  value rather than performing the check again, even if the ``<code>`` changes.
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  In order to force the check to be re-evaluated, the variable named by
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  ``<resultVar>`` must be manually removed from the cache.
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#]=======================================================================]
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Cristian Adam committed
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include_guard(GLOBAL)

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macro(CHECK_CXX_SOURCE_RUNS SOURCE VAR)
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  if(NOT DEFINED "${VAR}")
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    set(MACRO_CHECK_FUNCTION_DEFINITIONS
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      "-D${VAR} ${CMAKE_REQUIRED_FLAGS}")
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    if(CMAKE_REQUIRED_LINK_OPTIONS)
      set(CHECK_CXX_SOURCE_COMPILES_ADD_LINK_OPTIONS
        LINK_OPTIONS ${CMAKE_REQUIRED_LINK_OPTIONS})
    else()
      set(CHECK_CXX_SOURCE_COMPILES_ADD_LINK_OPTIONS)
    endif()
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    if(CMAKE_REQUIRED_LIBRARIES)
      set(CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES
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        LINK_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES})
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    else()
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      set(CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES)
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    endif()
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    if(CMAKE_REQUIRED_INCLUDES)
      set(CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES
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        "-DINCLUDE_DIRECTORIES:STRING=${CMAKE_REQUIRED_INCLUDES}")
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    else()
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      set(CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES)
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    endif()
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    file(WRITE "${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx"
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      "${SOURCE}\n")

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    if(NOT CMAKE_REQUIRED_QUIET)
      message(STATUS "Performing Test ${VAR}")
    endif()
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    try_run(${VAR}_EXITCODE ${VAR}_COMPILED
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      ${CMAKE_BINARY_DIR}
      ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/src.cxx
      COMPILE_DEFINITIONS ${CMAKE_REQUIRED_DEFINITIONS}
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      ${CHECK_CXX_SOURCE_COMPILES_ADD_LINK_OPTIONS}
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      ${CHECK_CXX_SOURCE_COMPILES_ADD_LIBRARIES}
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      CMAKE_FLAGS -DCOMPILE_DEFINITIONS:STRING=${MACRO_CHECK_FUNCTION_DEFINITIONS}
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      -DCMAKE_SKIP_RPATH:BOOL=${CMAKE_SKIP_RPATH}
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      "${CHECK_CXX_SOURCE_COMPILES_ADD_INCLUDES}"
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      COMPILE_OUTPUT_VARIABLE OUTPUT
      RUN_OUTPUT_VARIABLE RUN_OUTPUT)
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    # if it did not compile make the return value fail code of 1
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    if(NOT ${VAR}_COMPILED)
      set(${VAR}_EXITCODE 1)
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    endif()
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    # if the return value was 0 then it worked
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    if("${${VAR}_EXITCODE}" EQUAL 0)
      set(${VAR} 1 CACHE INTERNAL "Test ${VAR}")
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      if(NOT CMAKE_REQUIRED_QUIET)
        message(STATUS "Performing Test ${VAR} - Success")
      endif()
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      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
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        "Performing C++ SOURCE FILE Test ${VAR} succeeded with the following output:\n"
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        "${OUTPUT}\n"
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        "...and run output:\n"
        "${RUN_OUTPUT}\n"
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        "Return value: ${${VAR}}\n"
        "Source file was:\n${SOURCE}\n")
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    else()
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      if(CMAKE_CROSSCOMPILING AND "${${VAR}_EXITCODE}" MATCHES  "FAILED_TO_RUN")
        set(${VAR} "${${VAR}_EXITCODE}")
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      else()
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        set(${VAR} "" CACHE INTERNAL "Test ${VAR}")
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      endif()
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      if(NOT CMAKE_REQUIRED_QUIET)
        message(STATUS "Performing Test ${VAR} - Failed")
      endif()
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      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
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        "Performing C++ SOURCE FILE Test ${VAR} failed with the following output:\n"
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        "${OUTPUT}\n"
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        "...and run output:\n"
        "${RUN_OUTPUT}\n"
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        "Return value: ${${VAR}_EXITCODE}\n"
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        "Source file was:\n${SOURCE}\n")
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    endif()
  endif()
endmacro()