cmake/Modules/UseSWIG.cmake

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

#[=======================================================================[.rst:
UseSWIG
-------

This file provides support for ``SWIG``. It is assumed that :module:`FindSWIG`
module has already been loaded.

Defines the following command for use with ``SWIG``:

.. command:: swig_add_library

  Define swig module with given name and specified language::

    swig_add_library(<name>
                     [TYPE <SHARED|MODULE|STATIC|USE_BUILD_SHARED_LIBS>]
                     LANGUAGE <language>
                     [NO_PROXY]
                     [OUTPUT_DIR <directory>]
                     [OUTFILE_DIR <directory>]
                     SOURCES <file>...
                    )

  Targets created with the ``swig_add_library`` command have the same
  capabilities as targets created with the :command:`add_library` command, so
  those targets can be used with any command expecting a target (e.g.
  :command:`target_link_libraries`).

  .. note::

    The variable ``SWIG_MODULE_<name>_REAL_NAME`` will be set to the name
    of the swig module target library. This variable is useless if variable
    ``UseSWIG_TARGET_NAME_PREFERENCE`` is set to ``STANDARD``.

  .. note::

    For multi-config generators, this module does not support
    configuration-specific files generated by ``SWIG``. All build
    configurations must result in the same generated source file.

  ``TYPE``
    ``SHARED``, ``MODULE`` and ``STATIC`` have the same semantic as for the
    :command:`add_library` command. If ``USE_BUILD_SHARED_LIBS`` is specified,
    the library type will be ``STATIC`` or ``SHARED`` based on whether the
    current value of the :variable:`BUILD_SHARED_LIBS` variable is ``ON``. If
    no type is specified, ``MODULE`` will be used.

  ``LANGUAGE``
    Specify the target language.

  ``NO_PROXY``
    Prevent the generation of the wrapper layer (swig ``-noproxy`` option).

  ``OUTPUT_DIR``
    Specify where to write the language specific files (swig ``-outdir``
    option). If not given, the ``CMAKE_SWIG_OUTDIR`` variable will be used.
    If neither is specified, the default depends on the value of the
    ``UseSWIG_MODULE_VERSION`` variable as follows:

    * If ``UseSWIG_MODULE_VERSION`` is 1 or is undefined, output is written to
      the :variable:`CMAKE_CURRENT_BINARY_DIR` directory.
    * If ``UseSWIG_MODULE_VERSION`` is 2, a dedicated directory will be used.
      The path of this directory can be retrieved from the
      ``SWIG_SUPPORT_FILES_DIRECTORY`` target property.

  ``OUTFILE_DIR``
    Specify an output directory name where the generated source file will be
    placed (swig -o option). If not specified, the ``SWIG_OUTFILE_DIR`` variable
    will be used. If neither is specified, ``OUTPUT_DIR`` or
    ``CMAKE_SWIG_OUTDIR`` is used instead.

  ``SOURCES``
    List of sources for the library. Files with extension ``.i`` will be
    identified as sources for the ``SWIG`` tool. Other files will be handled in
    the standard way.

  .. note::

    If ``UseSWIG_MODULE_VERSION`` is set to 2, it is **strongly** recommended
    to use a dedicated directory unique to the target when either the
    ``OUTPUT_DIR`` option or the ``CMAKE_SWIG_OUTDIR`` variable are specified.
    The output directory contents are erased as part of the target build, so
    to prevent interference between targets or losing other important files,
    each target should have its own dedicated output directory.

.. command:: swig_link_libraries

  Link libraries to swig module::

    swig_link_libraries(<name> <item>...)

  This command has same capabilities as :command:`target_link_libraries`
  command.

  .. note::

    If variable ``UseSWIG_TARGET_NAME_PREFERENCE`` is set to ``STANDARD``, this
    command is deprecated and :command:`target_link_libraries` command must be
    used instead.

Source file properties on module files **must** be set before the invocation
of the ``swig_add_library`` command to specify special behavior of SWIG and
ensure generated files will receive the required settings.

``CPLUSPLUS``
  Call SWIG in c++ mode.  For example:

  .. code-block:: cmake

    set_property(SOURCE mymod.i PROPERTY CPLUSPLUS ON)
    swig_add_library(mymod LANGUAGE python SOURCES mymod.i)

``INCLUDE_DIRECTORIES``, ``COMPILE_DEFINITIONS`` and ``COMPILE_OPTIONS``
  Add custom flags to SWIG compiler and have same semantic as properties
  :prop_sf:`INCLUDE_DIRECTORIES`, :prop_sf:`COMPILE_DEFINITIONS` and
  :prop_sf:`COMPILE_OPTIONS`.

``GENERATED_INCLUDE_DIRECTORIES``, ``GENERATED_COMPILE_DEFINITIONS`` and ``GENERATED_COMPILE_OPTIONS``
  Add custom flags to the C/C++ generated source. They will fill, respectively,
  properties :prop_sf:`INCLUDE_DIRECTORIES`, :prop_sf:`COMPILE_DEFINITIONS` and
  :prop_sf:`COMPILE_OPTIONS` of generated C/C++ file.

``DEPENDS``
  Specify additional dependencies to the source file.

``SWIG_MODULE_NAME``
  Specify the actual import name of the module in the target language.
  This is required if it cannot be scanned automatically from source
  or different from the module file basename.  For example:

  .. code-block:: cmake

    set_property(SOURCE mymod.i PROPERTY SWIG_MODULE_NAME mymod_realname)

Target library properties can be set to apply same configuration to all SWIG
input files.

``SWIG_INCLUDE_DIRECTORIES``, ``SWIG_COMPILE_DEFINITIONS`` and ``SWIG_COMPILE_OPTIONS``
  These properties will be applied to all SWIG input files and have same
  semantic as target properties :prop_tgt:`INCLUDE_DIRECTORIES`,
  :prop_tgt:`COMPILE_DEFINITIONS` and :prop_tgt:`COMPILE_OPTIONS`.

  .. code-block:: cmake

    set (UseSWIG_TARGET_NAME_PREFERENCE STANDARD)
    swig_add_library(mymod LANGUAGE python SOURCES mymod.i)
    set_property(TARGET mymod PROPERTY SWIG_COMPILE_DEFINITIONS MY_DEF1 MY_DEF2)
    set_property(TARGET mymod PROPERTY SWIG_COMPILE_OPTIONS -bla -blb)

``SWIG_GENERATED_INCLUDE_DIRECTORIES``, ``SWIG_GENERATED_COMPILE_DEFINITIONS`` and ``SWIG_GENERATED_COMPILE_OPTIONS``
  These properties will populate, respectively, properties
  :prop_sf:`INCLUDE_DIRECTORIES`, :prop_sf:`COMPILE_DEFINITIONS` and
  :prop_sf:`COMPILE_FLAGS` of all generated C/C++ files.

``SWIG_DEPENDS``
  Add dependencies to all SWIG input files.

The following target properties are output properties and can be used to get
information about support files generated by ``SWIG`` interface compilation.

``SWIG_SUPPORT_FILES``
  This output property list of wrapper files generated during SWIG compilation.

  .. code-block:: cmake

    set (UseSWIG_TARGET_NAME_PREFERENCE STANDARD)
    swig_add_library(mymod LANGUAGE python SOURCES mymod.i)
    get_property(support_files TARGET mymod PROPERTY SWIG_SUPPORT_FILES)

  .. note::

    Only most principal support files are listed. In case some advanced
    features of ``SWIG`` are used (for example ``%template``), associated
    support files may not be listed. Prefer to use the
    ``SWIG_SUPPORT_FILES_DIRECTORY`` property to handle support files.

``SWIG_SUPPORT_FILES_DIRECTORY``
  This output property specifies the directory where support files will be
  generated.

Some variables can be set to customize the behavior of ``swig_add_library``
as well as ``SWIG``:

``UseSWIG_TARGET_NAME_PREFERENCE``
  Specify target name strategy.

  * Set to ``LEGACY`` or undefined: legacy strategy is applied. Variable
    ``SWIG_MODULE_<name>_REAL_NAME`` must be used to get real target name.
  * Set to ``STANDARD``: target name matches specified name.

``UseSWIG_MODULE_VERSION``
  Specify different behaviors for ``UseSWIG`` module.

  * Set to 1 or undefined: Legacy behavior is applied.
  * Set to 2: A new strategy is applied regarding support files: the output
    directory of support files is erased before ``SWIG`` interface compilation.

``CMAKE_SWIG_FLAGS``
  Add flags to all swig calls.

``CMAKE_SWIG_OUTDIR``
  Specify where to write the language specific files (swig ``-outdir`` option).

``SWIG_OUTFILE_DIR``
  Specify an output directory name where the generated source file will be
  placed.  If not specified, ``CMAKE_SWIG_OUTDIR`` is used.

``SWIG_MODULE_<name>_EXTRA_DEPS``
  Specify extra dependencies for the generated module for ``<name>``.
#]=======================================================================]


cmake_policy (VERSION 3.12)

set(SWIG_CXX_EXTENSION "cxx")
set(SWIG_EXTRA_LIBRARIES "")

set(SWIG_PYTHON_EXTRA_FILE_EXTENSIONS ".py")
set(SWIG_JAVA_EXTRA_FILE_EXTENSIONS ".java" "JNI.java")
set(SWIG_CSHARP_EXTRA_FILE_EXTENSIONS ".cs" "PINVOKE.cs")

##
## PRIVATE functions
##
function (__SWIG_COMPUTE_TIMESTAMP name language infile workingdir __timestamp)
  get_filename_component(filename "${infile}" NAME_WE)
  set(${__timestamp}
    "${workingdir}/${filename}${language}.stamp" PARENT_SCOPE)
  # get_filename_component(filename "${infile}" ABSOLUTE)
  # string(UUID uuid NAMESPACE 9735D882-D2F8-4E1D-88C9-A0A4F1F6ECA4
  #   NAME ${name}-${language}-${filename} TYPE SHA1)
  # set(${__timestamp} "${workingdir}/${uuid}.stamp" PARENT_SCOPE)
endfunction()

#
# For given swig module initialize variables associated with it
#
macro(SWIG_MODULE_INITIALIZE name language)
  string(TOUPPER "${language}" SWIG_MODULE_${name}_LANGUAGE)
  string(TOLOWER "${language}" SWIG_MODULE_${name}_SWIG_LANGUAGE_FLAG)

  if (NOT DEFINED SWIG_MODULE_${name}_NOPROXY)
    set (SWIG_MODULE_${name}_NOPROXY FALSE)
  endif()
  if ("-noproxy" IN_LIST CMAKE_SWIG_FLAGS)
    set (SWIG_MODULE_${name}_NOPROXY TRUE)
  endif ()

  if (SWIG_MODULE_${name}_NOPROXY AND
      NOT ("-noproxy" IN_LIST CMAKE_SWIG_FLAGS OR "-noproxy" IN_LIST SWIG_MODULE_${name}_EXTRA_FLAGS))
    list (APPEND SWIG_MODULE_${name}_EXTRA_FLAGS "-noproxy")
  endif()
  if(SWIG_MODULE_${name}_LANGUAGE STREQUAL "UNKNOWN")
    message(FATAL_ERROR "SWIG Error: Language \"${language}\" not found")
  elseif(SWIG_MODULE_${name}_LANGUAGE STREQUAL "PERL" AND
         NOT "-shadow" IN_LIST SWIG_MODULE_${name}_EXTRA_FLAGS)
    list(APPEND SWIG_MODULE_${name}_EXTRA_FLAGS "-shadow")
  endif()
endmacro()

#
# For a given language, input file, and output file, determine extra files that
# will be generated. This is internal swig macro.
#

function(SWIG_GET_EXTRA_OUTPUT_FILES language outfiles generatedpath infile)
  set(files)
  get_source_file_property(module_basename
    "${infile}" SWIG_MODULE_NAME)
  if(NOT module_basename)

    # try to get module name from "%module foo" syntax
    if ( EXISTS "${infile}" )
      file ( STRINGS "${infile}" module_basename REGEX "[ ]*%module[ ]*[a-zA-Z0-9_]+.*" )
    endif ()
    if ( module_basename )
      string ( REGEX REPLACE "[ ]*%module[ ]*([a-zA-Z0-9_]+).*" "\\1" module_basename "${module_basename}" )

    else ()
      # try to get module name from "%module (options=...) foo" syntax
      if ( EXISTS "${infile}" )
        file ( STRINGS "${infile}" module_basename REGEX "[ ]*%module[ ]*\\(.*\\)[ ]*[a-zA-Z0-9_]+.*" )
      endif ()
      if ( module_basename )
        string ( REGEX REPLACE "[ ]*%module[ ]*\\(.*\\)[ ]*([a-zA-Z0-9_]+).*" "\\1" module_basename "${module_basename}" )

      else ()
        # fallback to file basename
        get_filename_component(module_basename "${infile}" NAME_WE)
      endif ()
    endif ()

  endif()
  foreach(it ${SWIG_${language}_EXTRA_FILE_EXTENSIONS})
    set(extra_file "${generatedpath}/${module_basename}${it}")
    if (extra_file MATCHES "\\.cs$" AND CMAKE_CSharp_COMPILER_LOADED)
      set_source_files_properties(${extra_file} PROPERTIES LANGUAGE "CSharp")
    else()
      # Treat extra outputs as plain files regardless of language.
      set_source_files_properties(${extra_file} PROPERTIES LANGUAGE "")
    endif()
    list(APPEND files "${extra_file}")
  endforeach()

  set (${outfiles} ${files} PARENT_SCOPE)
endfunction()

#
# Take swig (*.i) file and add proper custom commands for it
#
function(SWIG_ADD_SOURCE_TO_MODULE name outfiles infile)
  get_filename_component(swig_source_file_name_we "${infile}" NAME_WE)
  get_source_file_property(swig_source_file_cplusplus "${infile}" CPLUSPLUS)

  # If CMAKE_SWIG_OUTDIR was specified then pass it to -outdir
  if(CMAKE_SWIG_OUTDIR)
    set(outdir ${CMAKE_SWIG_OUTDIR})
  else()
    set(outdir ${CMAKE_CURRENT_BINARY_DIR})
  endif()

  if(SWIG_OUTFILE_DIR)
    set(outfiledir ${SWIG_OUTFILE_DIR})
  else()
    set(outfiledir ${outdir})
  endif()

  if(SWIG_WORKING_DIR)
    set (workingdir "${SWIG_WORKING_DIR}")
  else()
    set(workingdir "${outdir}")
  endif()

  if(SWIG_TARGET_NAME)
    set(target_name ${SWIG_TARGET_NAME})
  else()
    set(target_name ${name})
  endif()

  set (swig_source_file_flags ${CMAKE_SWIG_FLAGS})
  # handle various swig compile flags properties
  get_source_file_property (include_directories "${infile}" INCLUDE_DIRECTORIES)
  if (include_directories)
    list (APPEND swig_source_file_flags "$<$<BOOL:${include_directories}>:-I$<JOIN:${include_directories},$<SEMICOLON>-I>>")
  endif()
  set (property "$<TARGET_PROPERTY:${target_name},SWIG_INCLUDE_DIRECTORIES>")
  list (APPEND swig_source_file_flags "$<$<BOOL:${property}>:-I$<JOIN:$<TARGET_GENEX_EVAL:${target_name},${property}>,$<SEMICOLON>-I>>")

  set (property "$<TARGET_PROPERTY:${target_name},SWIG_COMPILE_DEFINITIONS>")
  list (APPEND swig_source_file_flags "$<$<BOOL:${property}>:-D$<JOIN:$<TARGET_GENEX_EVAL:${target_name},${property}>,$<SEMICOLON>-D>>")
  get_source_file_property (compile_definitions "${infile}" COMPILE_DEFINITIONS)
  if (compile_definitions)
    list (APPEND swig_source_file_flags "$<$<BOOL:${compile_definitions}>:-D$<JOIN:${compile_definitions},$<SEMICOLON>-D>>")
  endif()

  list (APPEND swig_source_file_flags "$<TARGET_GENEX_EVAL:${target_name},$<TARGET_PROPERTY:${target_name},SWIG_COMPILE_OPTIONS>>")
  get_source_file_property (compile_options "${infile}" COMPILE_OPTIONS)
  if (compile_options)
    list (APPEND swig_source_file_flags ${compile_options})
  endif()

  # legacy support
  get_source_file_property (swig_flags "${infile}" SWIG_FLAGS)
  if (swig_flags)
    list (APPEND swig_source_file_flags ${swig_flags})
  endif()

  get_filename_component(swig_source_file_fullname "${infile}" ABSOLUTE)

  if (NOT SWIG_MODULE_${name}_NOPROXY)
    SWIG_GET_EXTRA_OUTPUT_FILES(${SWIG_MODULE_${name}_LANGUAGE}
      swig_extra_generated_files
      "${outdir}"
      "${swig_source_file_fullname}")
  endif()
  set(swig_generated_file_fullname
    "${outfiledir}/${swig_source_file_name_we}")
  # add the language into the name of the file (i.e. TCL_wrap)
  # this allows for the same .i file to be wrapped into different languages
  string(APPEND swig_generated_file_fullname
    "${SWIG_MODULE_${name}_LANGUAGE}_wrap")

  if(swig_source_file_cplusplus)
    string(APPEND swig_generated_file_fullname
      ".${SWIG_CXX_EXTENSION}")
  else()
    string(APPEND swig_generated_file_fullname
      ".c")
  endif()

  get_directory_property (cmake_include_directories INCLUDE_DIRECTORIES)
  list (REMOVE_DUPLICATES cmake_include_directories)
  set (swig_include_dirs)
  if (cmake_include_directories)
    set (swig_include_dirs "$<$<BOOL:${cmake_include_directories}>:-I$<JOIN:${cmake_include_directories},$<SEMICOLON>-I>>")
  endif()

  set(swig_special_flags)
  # default is c, so add c++ flag if it is c++
  if(swig_source_file_cplusplus)
    list (APPEND swig_special_flags "-c++")
  endif()

  set (swig_extra_flags)
  if(SWIG_MODULE_${name}_LANGUAGE STREQUAL "CSHARP")
    if(NOT ("-dllimport" IN_LIST swig_source_file_flags OR "-dllimport" IN_LIST SWIG_MODULE_${name}_EXTRA_FLAGS))
      # This makes sure that the name used in the generated DllImport
      # matches the library name created by CMake
      list (APPEND SWIG_MODULE_${name}_EXTRA_FLAGS "-dllimport" "${name}")
    endif()
  endif()
  list (APPEND swig_extra_flags ${SWIG_MODULE_${name}_EXTRA_FLAGS})

  # dependencies
  set (swig_dependencies ${SWIG_MODULE_${name}_EXTRA_DEPS} $<TARGET_PROPERTY:${target_name},SWIG_DEPENDS>)
  get_source_file_property(file_depends "${infile}" DEPENDS)
  if (file_depends)
    list (APPEND swig_dependencies ${file_depends})
  endif()

  if (UseSWIG_MODULE_VERSION VERSION_GREATER 1)
    # as part of custom command, start by removing old generated files
    # to ensure obsolete files do not stay
    set (swig_cleanup_command COMMAND "${CMAKE_COMMAND}" -E remove_directory "${outdir}")
  else()
    unset (swig_cleanup_command)
  endif()

  # IMPLICIT_DEPENDS below can not handle situations where a dependent file is
  # removed. We need an extra step with timestamp and custom target, see #16830
  # As this is needed only for Makefile generator do it conditionally
  if(CMAKE_GENERATOR MATCHES "Make")
    __swig_compute_timestamp(${name} ${SWIG_MODULE_${name}_LANGUAGE}
      "${infile}" "${workingdir}" swig_generated_timestamp)
    set(swig_custom_output "${swig_generated_timestamp}")
    set(swig_custom_products
      BYPRODUCTS "${swig_generated_file_fullname}" ${swig_extra_generated_files})
    set(swig_timestamp_command
      COMMAND ${CMAKE_COMMAND} -E touch "${swig_generated_timestamp}")
  else()
    set(swig_custom_output
      "${swig_generated_file_fullname}" ${swig_extra_generated_files})
    set(swig_custom_products)
    set(swig_timestamp_command)
  endif()
  add_custom_command(
    OUTPUT ${swig_custom_output}
    ${swig_custom_products}
    ${swig_cleanup_command}
    # Let's create the ${outdir} at execution time, in case dir contains $(OutDir)
    COMMAND "${CMAKE_COMMAND}" -E make_directory ${outdir} ${outfiledir}
    ${swig_timestamp_command}
    COMMAND "${CMAKE_COMMAND}" -E env "SWIG_LIB=${SWIG_DIR}" "${SWIG_EXECUTABLE}"
    "-${SWIG_MODULE_${name}_SWIG_LANGUAGE_FLAG}"
    "${swig_source_file_flags}"
    -outdir "${outdir}"
    ${swig_special_flags}
    ${swig_extra_flags}
    "${swig_include_dirs}"
    -o "${swig_generated_file_fullname}"
    "${swig_source_file_fullname}"
    MAIN_DEPENDENCY "${swig_source_file_fullname}"
    DEPENDS ${swig_dependencies}
    IMPLICIT_DEPENDS CXX "${swig_source_file_fullname}"
    COMMENT "Swig source"
    COMMAND_EXPAND_LISTS)
  set_source_files_properties("${swig_generated_file_fullname}" ${swig_extra_generated_files}
    PROPERTIES GENERATED 1)

  ## add all properties for generated file to various properties
  get_property (include_directories SOURCE "${infile}" PROPERTY GENERATED_INCLUDE_DIRECTORIES)
  set_property (SOURCE "${swig_generated_file_fullname}" PROPERTY INCLUDE_DIRECTORIES ${include_directories} $<TARGET_GENEX_EVAL:${target_name},$<TARGET_PROPERTY:${target_name},SWIG_GENERATED_INCLUDE_DIRECTORIES>>)

  get_property (compile_definitions SOURCE "${infile}" PROPERTY GENERATED_COMPILE_DEFINITIONS)
  set_property (SOURCE "${swig_generated_file_fullname}" PROPERTY COMPILE_DEFINITIONS $<TARGET_GENEX_EVAL:${target_name},$<TARGET_PROPERTY:${target_name},SWIG_GENERATED_COMPILE_DEFINITIONS>> ${compile_definitions})

  get_property (compile_options SOURCE "${infile}" PROPERTY GENERATED_COMPILE_OPTIONS)
  set_property (SOURCE "${swig_generated_file_fullname}" PROPERTY COMPILE_OPTIONS $<TARGET_GENEX_EVAL:${target_name},$<TARGET_PROPERTY:${target_name},SWIG_GENERATED_COMPILE_OPTIONS>> ${compile_options})

  set(${outfiles} "${swig_generated_file_fullname}" ${swig_extra_generated_files} PARENT_SCOPE)

  # legacy support
  set (swig_generated_file_fullname "${swig_generated_file_fullname}" PARENT_SCOPE)
endfunction()

#
# Create Swig module
#
macro(SWIG_ADD_MODULE name language)
  message(DEPRECATION "SWIG_ADD_MODULE is deprecated. Use SWIG_ADD_LIBRARY instead.")
  swig_add_library(${name}
                   LANGUAGE ${language}
                   TYPE MODULE
                   SOURCES ${ARGN})
endmacro()


function(SWIG_ADD_LIBRARY name)
  set(options NO_PROXY)
  set(oneValueArgs LANGUAGE
                   TYPE
                   OUTPUT_DIR
                   OUTFILE_DIR)
  set(multiValueArgs SOURCES)
  cmake_parse_arguments(_SAM "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})

  if (_SAM_UNPARSED_ARGUMENTS)
    message(FATAL_ERROR "SWIG_ADD_LIBRARY: ${_SAM_UNPARSED_ARGUMENTS}: unexpected arguments")
  endif()

  if(NOT DEFINED _SAM_LANGUAGE)
    message(FATAL_ERROR "SWIG_ADD_LIBRARY: Missing LANGUAGE argument")
  endif()

  if(NOT DEFINED _SAM_SOURCES)
    message(FATAL_ERROR "SWIG_ADD_LIBRARY: Missing SOURCES argument")
  endif()

  if(NOT DEFINED _SAM_TYPE)
    set(_SAM_TYPE MODULE)
  elseif(_SAM_TYPE STREQUAL "USE_BUILD_SHARED_LIBS")
    unset(_SAM_TYPE)
  endif()

  if (NOT DEFINED UseSWIG_TARGET_NAME_PREFERENCE)
    set (UseSWIG_TARGET_NAME_PREFERENCE LEGACY)
  elseif (NOT UseSWIG_TARGET_NAME_PREFERENCE MATCHES "^(LEGACY|STANDARD)$")
    message (FATAL_ERROR "UseSWIG_TARGET_NAME_PREFERENCE: ${UseSWIG_TARGET_NAME_PREFERENCE}: invalid value. 'LEGACY' or 'STANDARD' is expected.")
  endif()

  if (NOT DEFINED UseSWIG_MODULE_VERSION)
    set (UseSWIG_MODULE_VERSION 1)
  elseif (NOT UseSWIG_MODULE_VERSION MATCHES "^(1|2)$")
    message (FATAL_ERROR "UseSWIG_MODULE_VERSION: ${UseSWIG_MODULE_VERSION}: invalid value. 1 or 2 is expected.")
  endif()

  set (SWIG_MODULE_${name}_NOPROXY ${_SAM_NO_PROXY})
  swig_module_initialize(${name} ${_SAM_LANGUAGE})

  # compute real target name.
  if (UseSWIG_TARGET_NAME_PREFERENCE STREQUAL "LEGACY" AND
      SWIG_MODULE_${name}_LANGUAGE STREQUAL "PYTHON" AND NOT SWIG_MODULE_${name}_NOPROXY)
    # swig will produce a module.py containing an 'import _modulename' statement,
    # which implies having a corresponding _modulename.so (*NIX), _modulename.pyd (Win32),
    # unless the -noproxy flag is used
    set(target_name "_${name}")
  else()
    set(target_name "${name}")
  endif()

  if (TARGET ${target_name})
    # a target with same name is already defined.
    # call NOW add_library command to raise the most useful error message
    add_library(${target_name})
    return()
  endif()

  set (workingdir "${CMAKE_CURRENT_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/${target_name}.dir")
  # set special variable to pass extra information to command SWIG_ADD_SOURCE_TO_MODULE
  # which cannot be changed due to legacy compatibility
  set (SWIG_WORKING_DIR "${workingdir}")
  set (SWIG_TARGET_NAME "${target_name}")

  set (outputdir "${_SAM_OUTPUT_DIR}")
  if (NOT _SAM_OUTPUT_DIR)
    if (CMAKE_SWIG_OUTDIR)
      set (outputdir "${CMAKE_SWIG_OUTDIR}")
    else()
      if (UseSWIG_MODULE_VERSION VERSION_GREATER 1)
        set (outputdir "${workingdir}/${_SAM_LANGUAGE}.files")
      else()
        set (outputdir "${CMAKE_CURRENT_BINARY_DIR}")
      endif()
    endif()
  endif()

  set (outfiledir "${_SAM_OUTFILE_DIR}")
  if(NOT _SAM_OUTFILE_DIR)
    if (SWIG_OUTFILE_DIR)
      set (outfiledir "${SWIG_OUTFILE_DIR}")
    else()
      if (_SAM_OUTPUT_DIR OR CMAKE_SWIG_OUTDIR)
        set (outfiledir "${outputdir}")
    else()
        set (outfiledir "${workingdir}")
      endif()
    endif()
  endif()
  # set again, locally, predefined variables to ensure compatibility
  # with command SWIG_ADD_SOURCE_TO_MODULE
  set(CMAKE_SWIG_OUTDIR "${outputdir}")
  set(SWIG_OUTFILE_DIR "${outfiledir}")

  set(swig_dot_i_sources ${_SAM_SOURCES})
  list(FILTER swig_dot_i_sources INCLUDE REGEX "\\.i$")
  if (NOT swig_dot_i_sources)
    message(FATAL_ERROR "SWIG_ADD_LIBRARY: no SWIG interface files specified")
  endif()
  set(swig_other_sources ${_SAM_SOURCES})
  list(REMOVE_ITEM swig_other_sources ${swig_dot_i_sources})

  set(swig_generated_sources)
  set(swig_generated_timestamps)
  foreach(swig_it IN LISTS swig_dot_i_sources)
    SWIG_ADD_SOURCE_TO_MODULE(${name} swig_generated_source "${swig_it}")
    list (APPEND swig_generated_sources "${swig_generated_source}")
    if(CMAKE_GENERATOR MATCHES "Make")
      __swig_compute_timestamp(${name} ${SWIG_MODULE_${name}_LANGUAGE} "${swig_it}"
        "${workingdir}" swig_timestamp)
      list (APPEND swig_generated_timestamps "${swig_timestamp}")
    endif()
  endforeach()
  set_property (DIRECTORY APPEND PROPERTY
    ADDITIONAL_MAKE_CLEAN_FILES ${swig_generated_sources} ${swig_generated_timestamps})
  if (UseSWIG_MODULE_VERSION VERSION_GREATER 1)
    set_property (DIRECTORY APPEND PROPERTY ADDITIONAL_MAKE_CLEAN_FILES "${outputdir}")
  endif()

  add_library(${target_name}
    ${_SAM_TYPE}
    ${swig_generated_sources}
    ${swig_other_sources})
  if(CMAKE_GENERATOR MATCHES "Make")
    # see IMPLICIT_DEPENDS above
    add_custom_target(${name}_swig_compilation DEPENDS ${swig_generated_timestamps})
    add_dependencies(${target_name} ${name}_swig_compilation)
  endif()
  if(_SAM_TYPE STREQUAL "MODULE")
    set_target_properties(${target_name} PROPERTIES NO_SONAME ON)
  endif()
  string(TOLOWER "${_SAM_LANGUAGE}" swig_lowercase_language)
  if (swig_lowercase_language STREQUAL "octave")
    set_target_properties(${target_name} PROPERTIES PREFIX "")
    set_target_properties(${target_name} PROPERTIES SUFFIX ".oct")
  elseif (swig_lowercase_language STREQUAL "go")
    set_target_properties(${target_name} PROPERTIES PREFIX "")
  elseif (swig_lowercase_language STREQUAL "java")
    # In java you want:
    #      System.loadLibrary("LIBRARY");
    # then JNI will look for a library whose name is platform dependent, namely
    #   MacOS  : libLIBRARY.jnilib
    #   Windows: LIBRARY.dll
    #   Linux  : libLIBRARY.so
    if (APPLE)
      set_target_properties (${target_name} PROPERTIES SUFFIX ".jnilib")
    endif()
    if ((WIN32 AND MINGW) OR CYGWIN OR CMAKE_SYSTEM_NAME STREQUAL MSYS)
      set_target_properties(${target_name} PROPERTIES PREFIX "")
    endif()
  elseif (swig_lowercase_language STREQUAL "lua")
    if(_SAM_TYPE STREQUAL "MODULE")
      set_target_properties(${target_name} PROPERTIES PREFIX "")
    endif()
  elseif (swig_lowercase_language STREQUAL "python")
    if (UseSWIG_TARGET_NAME_PREFERENCE STREQUAL "STANDARD" AND NOT SWIG_MODULE_${name}_NOPROXY)
      # swig will produce a module.py containing an 'import _modulename' statement,
      # which implies having a corresponding _modulename.so (*NIX), _modulename.pyd (Win32),
      # unless the -noproxy flag is used
      set_target_properties(${target_name} PROPERTIES PREFIX "_")
    else()
      set_target_properties(${target_name} PROPERTIES PREFIX "")
    endif()
    # Python extension modules on Windows must have the extension ".pyd"
    # instead of ".dll" as of Python 2.5.  Older python versions do support
    # this suffix.
    # http://docs.python.org/whatsnew/ports.html#SECTION0001510000000000000000
    # <quote>
    # Windows: .dll is no longer supported as a filename extension for extension modules.
    # .pyd is now the only filename extension that will be searched for.
    # </quote>
    if(WIN32 AND NOT CYGWIN)
      set_target_properties(${target_name} PROPERTIES SUFFIX ".pyd")
    endif()
  elseif (swig_lowercase_language STREQUAL "r")
    set_target_properties(${target_name} PROPERTIES PREFIX "")
  elseif (swig_lowercase_language STREQUAL "ruby")
    # In ruby you want:
    #      require 'LIBRARY'
    # then ruby will look for a library whose name is platform dependent, namely
    #   MacOS  : LIBRARY.bundle
    #   Windows: LIBRARY.dll
    #   Linux  : LIBRARY.so
    set_target_properties (${target_name} PROPERTIES PREFIX "")
    if (APPLE)
      set_target_properties (${target_name} PROPERTIES SUFFIX ".bundle")
    endif ()
  elseif (swig_lowercase_language STREQUAL "perl")
    # assume empty prefix because we expect the module to be dynamically loaded
    set_target_properties (${target_name} PROPERTIES PREFIX "")
    if (APPLE)
      set_target_properties (${target_name} PROPERTIES SUFFIX ".dylib")
    endif ()
  else()
    # assume empty prefix because we expect the module to be dynamically loaded
    set_target_properties (${target_name} PROPERTIES PREFIX "")
  endif ()

  # target property SWIG_SUPPORT_FILES_DIRECTORY specify output directory of support files
  set_property (TARGET ${target_name} PROPERTY SWIG_SUPPORT_FILES_DIRECTORY "${outputdir}")
  # target property SWIG_SUPPORT_FILES lists principal proxy support files
  if (NOT SWIG_MODULE_${name}_NOPROXY)
    string(TOUPPER "${_SAM_LANGUAGE}" swig_uppercase_language)
    set(swig_all_support_files)
    foreach (swig_it IN LISTS SWIG_${swig_uppercase_language}_EXTRA_FILE_EXTENSIONS)
      set (swig_support_files ${swig_generated_sources})
      list (FILTER swig_support_files INCLUDE REGEX ".*${swig_it}$")
      list(APPEND swig_all_support_files ${swig_support_files})
    endforeach()
    if (swig_all_support_files)
      list(REMOVE_DUPLICATES swig_all_support_files)
    endif()
    set_property (TARGET ${target_name} PROPERTY SWIG_SUPPORT_FILES ${swig_all_support_files})
  endif()

  # to ensure legacy behavior, export some variables
  set (SWIG_MODULE_${name}_LANGUAGE "${SWIG_MODULE_${name}_LANGUAGE}" PARENT_SCOPE)
  set (SWIG_MODULE_${name}_SWIG_LANGUAGE_FLAG "${SWIG_MODULE_${name}_SWIG_LANGUAGE_FLAG}" PARENT_SCOPE)
  set (SWIG_MODULE_${name}_REAL_NAME "${target_name}" PARENT_SCOPE)
  set (SWIG_MODULE_${name}_NOPROXY "${SWIG_MODULE_${name}_NOPROXY}" PARENT_SCOPE)
  set (SWIG_MODULE_${name}_EXTRA_FLAGS "${SWIG_MODULE_${name}_EXTRA_FLAGS}" PARENT_SCOPE)
  # the last one is a bit crazy but it is documented, so...
  # NOTA: works as expected if only ONE input file is specified
  set (swig_generated_file_fullname "${swig_generated_file_fullname}" PARENT_SCOPE)
endfunction()

#
# Like TARGET_LINK_LIBRARIES but for swig modules
#
function(SWIG_LINK_LIBRARIES name)
  if (UseSWIG_TARGET_NAME_PREFERENCE STREQUAL "STANDARD")
    message(DEPRECATION "SWIG_LINK_LIBRARIES is deprecated. Use TARGET_LINK_LIBRARIES instead.")
    target_link_libraries(${name} ${ARGN})
  else()
    if(SWIG_MODULE_${name}_REAL_NAME)
      target_link_libraries(${SWIG_MODULE_${name}_REAL_NAME} ${ARGN})
    else()
      message(SEND_ERROR "Cannot find Swig library \"${name}\".")
    endif()
  endif()
endfunction()