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

include_guard(GLOBAL)

#[=======================================================================[.rst:
FeatureSummary
--------------

.. only:: html

   .. contents::

This module provides commands for generating a summary of enabled/disabled
features.

Load this module in CMake with:

.. code-block:: cmake

  include(FeatureSummary)

Commands provided by this module can be used to generate a summary of enabled
and disabled packages and/or features for a build tree such as::

  -- The following features have been enabled:

   * Example, usage example

  -- The following OPTIONAL packages have been found:

   * LibXml2 (required version >= 2.4), XML library, <http://xmlsoft.org>
     Enables HTML-import in MyWordProcessor
     Enables odt-export in MyWordProcessor
   * PNG, image library, <http://www.libpng.org/pub/png/>
     Enables saving screenshots

  -- The following OPTIONAL packages have not been found:

   * Lua, the Lua scripting language, <https://www.lua.org>
     Enables macros in MyWordProcessor
   * OpenGL, Open Graphics Library

Global Properties
^^^^^^^^^^^^^^^^^

The following global properties are used by this module:

.. variable:: FeatureSummary_PKG_TYPES

  .. versionadded:: 3.8

  This global property defines a
  :ref:`semicolon-separated list <CMake Language Lists>` of package types used
  by the ``FeatureSummary`` module.

  The order in this list is important, the first package type in the list has
  the lowest importance, while the last has the highest importance.  The type of
  a package can only be changed to a type with higher importance.

  The default package types are ``RUNTIME``, ``OPTIONAL``, ``RECOMMENDED`` and
  ``REQUIRED``, with their importance ranked as
  ``RUNTIME < OPTIONAL < RECOMMENDED < REQUIRED``.

.. variable:: FeatureSummary_REQUIRED_PKG_TYPES

  .. versionadded:: 3.8

  This global property defines a
  :ref:`semicolon-separated list <CMake Language Lists>` of package types that
  are considered required.

  If one or more packages in these categories are not found, CMake will abort
  when the :command:`feature_summary()` command is called with the
  ``FATAL_ON_MISSING_REQUIRED_PACKAGES`` option enabled.

  The default value for this global property is ``REQUIRED``.

.. variable:: FeatureSummary_DEFAULT_PKG_TYPE

  .. versionadded:: 3.8

  This global property defines the default package type.

  When the :command:`feature_summary()` command is called, and the user has
  not explicitly set a type of some package, its type will be set to the
  value of this property.

  This value must be one of the types defined in the
  :variable:`FeatureSummary_PKG_TYPES` global property.

  The default value for this global property is ``OPTIONAL``.

.. variable:: FeatureSummary_<TYPE>_DESCRIPTION

  .. versionadded:: 3.9

  This global property can be defined for each package ``<TYPE>`` to a string
  that will be used in the output titles of the
  :command:`feature_summary()` command.  For example::

      The following <FeatureSummary_<TYPE>_DESCRIPTION> have been found:

  If not set, default string ``<TYPE> packages`` is used.

Commands
^^^^^^^^

This module provides the following commands:

* :command:`feature_summary`
* :command:`set_package_properties`
* :command:`add_feature_info`

Printing Feature Summary
""""""""""""""""""""""""

.. command:: feature_summary

  Prints information about enabled or disabled packages and features of a
  project:

  .. code-block:: cmake

    feature_summary(
      WHAT (ALL
        | PACKAGES_FOUND | PACKAGES_NOT_FOUND
        | <TYPE>_PACKAGES_FOUND | <TYPE>_PACKAGES_NOT_FOUND
        | ENABLED_FEATURES | DISABLED_FEATURES)
      [FILENAME <file>]
      [APPEND]
      [VAR <variable-name>]
      [INCLUDE_QUIET_PACKAGES]
      [FATAL_ON_MISSING_REQUIRED_PACKAGES]
      [DESCRIPTION <description> | DEFAULT_DESCRIPTION]
      [QUIET_ON_EMPTY]
    )

  This command can be used to print information about enabled or disabled
  packages and features of a project.  By default, only the names of the
  features/packages will be printed and their required version when one was
  specified.  Use :command:`set_package_properties()` to add more useful
  information, e.g., a homepage URL for the respective package or their
  purpose in the project.

  .. rubric:: The arguments are:

  ``WHAT``
    This is the only mandatory option.  It specifies what information will be
    printed:

    ``ALL``
      Print everything.
    ``ENABLED_FEATURES``
      The list of all features which are enabled.
    ``DISABLED_FEATURES``
      The list of all features which are disabled.
    ``PACKAGES_FOUND``
      The list of all packages which have been found.
    ``PACKAGES_NOT_FOUND``
      The list of all packages which have not been found.

    For each package type ``<TYPE>`` defined by the
    :variable:`FeatureSummary_PKG_TYPES` global property, the following
    information can also be used:

    ``<TYPE>_PACKAGES_FOUND``
      The list of only packages of type ``<TYPE>`` which have been found.
    ``<TYPE>_PACKAGES_NOT_FOUND``
      The list of only packages of type ``<TYPE>`` which have not been found.

    .. versionchanged:: 3.1
      The ``WHAT`` option is now a multi-value keyword, so that these values can
      be combined, with the exception of the ``ALL`` value, in order to
      customize the output.  For example:

    .. code-block:: cmake

      feature_summary(WHAT ENABLED_FEATURES DISABLED_FEATURES)

  ``FILENAME <file>``
    If this option is given, the information is printed into this file instead
    of the terminal.  Relative ``<file>`` path is interpreted as being relative
    to the current source directory (i.e. :variable:`CMAKE_CURRENT_SOURCE_DIR`).

  ``APPEND``
    If this option is given, the output is appended to the ``<file>`` provided
    by the ``FILENAME`` option, otherwise the file is overwritten if it already
    exists.

  ``VAR <variable-name>``
    If this option is given, the information is stored into the specified
    variable ``<variable-name>`` instead of the terminal.

  ``INCLUDE_QUIET_PACKAGES``
    If this option is given, packages which have been searched with
    :command:`find_package(... QUIET)` will also be listed.  By default they are
    skipped.

  ``FATAL_ON_MISSING_REQUIRED_PACKAGES``
    If this option is given, CMake will abort with fatal error if a package
    which is marked as one of the package types listed in the
    :variable:`FeatureSummary_REQUIRED_PKG_TYPES` global property has not been
    found.

  ``DESCRIPTION <description>``
    A description or headline which will be printed above the actual content.
    Without this option, if only one package type was requested, no title is
    printed, unless a custom string is explicitly set using this option or
    ``DEFAULT_DESCRIPTION`` option is used that outputs a default title for the
    requested type.

  ``DEFAULT_DESCRIPTION``
    .. versionadded:: 3.9

    The default description or headline to be printed above the content as
    opposed to the customizable ``DESCRIPTION <description>``.

  ``QUIET_ON_EMPTY``
    .. versionadded:: 3.8

    If this option is given, when only one package type was requested, and no
    packages belonging to that category were found, then no output (including
    the ``DESCRIPTION``) is printed nor added to the ``FILENAME``, or the
    ``VAR`` variable.

Package Properties
""""""""""""""""""

.. command:: set_package_properties

  Sets package properties:

  .. code-block:: cmake

    set_package_properties(
      <PackageName>
      PROPERTIES
        [URL <url>]
        [DESCRIPTION <description>]
        [TYPE (RUNTIME|OPTIONAL|RECOMMENDED|REQUIRED)]
        [PURPOSE <purpose>]
    )

  Use this command to configure and provide information about the package
  named ``<PackageName>``, which can then be displayed using the
  :command:`feature_summary()` command.  This command can be called either
  directly within the corresponding :ref:`Find module <Find Modules>` or in
  the project that uses the module after invoking the :command:`find_package()`
  call.  The features for which information can be set are determined
  automatically after the :command:`find_package()` command.

  .. rubric:: The arguments are:

  ``<PackageName>``
    The name of the package.  For example, as specified in the
    :command:`find_package(<PackageName>)` argument.

  ``PROPERTIES``
    Specifies the properties to set:

    ``URL <url>``
      This should be the homepage of the package, or something similar.
      Ideally this is set already directly in the
      :ref:`Find module <Find Modules>`.

    ``DESCRIPTION <description>``
      A short description what that package is, at most one sentence.
      Ideally this is set already directly in the
      :ref:`Find module <Find Modules>`.

    ``TYPE <type>``
      What type of dependency has the using project on that package.

      Default ``<type>`` is ``OPTIONAL``.  In this case it is a package
      which can be used by the project when available at buildtime, but the
      project also works without it.

      ``RECOMMENDED`` package type is similar to ``OPTIONAL``, i.e.  the
      project will build if the package is not present, but the
      functionality of the resulting binaries will be severely limited.  If
      a ``REQUIRED`` package is not available at buildtime, the project may
      not even build. This can be combined with the
      :command:`feature_summary(FATAL_ON_MISSING_REQUIRED_PACKAGES)` command
      option.

      Last, a ``RUNTIME`` package is a package which is actually not used
      at all during the build, but which is required for actually running
      the resulting binaries.  So if such a package is missing, the project
      can still be built, but it may not work later on.

      If ``set_package_properties()`` is called multiple times for the same
      package with different TYPEs, the ``TYPE`` is only changed to higher
      TYPEs (``RUNTIME < OPTIONAL < RECOMMENDED < REQUIRED``), lower TYPEs
      are ignored.  The ``TYPE`` property is project-specific, so it cannot
      be set by the :ref:`Find module <Find Modules>`, but must be set in
      the project.

      The accepted types can be changed by setting the
      :variable:`FeatureSummary_PKG_TYPES` global property.

    ``PURPOSE <purpose>``
      This describes which features this package enables in the project,
      i.e.  it tells the user what functionality they get in the resulting
      binaries.  If ``set_package_properties()`` is called multiple times
      for a package, all ``PURPOSE`` properties are appended to a list of
      purposes of the package in the project.  As the ``TYPE`` property,
      also the ``PURPOSE`` property is project-specific, so it cannot be
      set by the :ref:`Find module <Find Modules>`, but must be set in the
      project.

Adding Feature Info
"""""""""""""""""""

.. command:: add_feature_info

  Adds feature information:

  .. code-block:: cmake

    add_feature_info(<name> <condition> <description>)

  Use this command to add information about a feature identified with a given
  ``<name>``.

  .. rubric:: The arguments are:

  ``<name>``
    Identification name for a feature being added.

  ``<condition>``
    Specifies the conditions that determine whether this feature is enabled
    or disabled.

    The ``<condition>`` argument can be:

    * A single condition (such as a variable name).

    * .. versionadded:: 3.8
        A :ref:`semicolon-separated list <CMake Language Lists>` of multiple
        conditions.

    * .. versionadded:: 4.0
        A full :ref:`Condition Syntax` as used in an ``if(<condition>)``
        clause.  See policy :policy:`CMP0183`.  This enables using entire
        condition syntax (such as grouping conditions with parens and
        similar).

  ``<description>``
    A text describing the feature.  This information can be displayed using
    :command:`feature_summary()` for ``ENABLED_FEATURES`` and
    ``DISABLED_FEATURES`` respectively.

Deprecated Commands
"""""""""""""""""""

The following legacy and deprecated commands are provided for backward
compatibility with previous CMake versions:

.. command:: set_package_info

  .. deprecated:: 3.8
    Use the :command:`set_package_properties`, and :command:`add_feature_info`
    commands instead.

  Sets up information about the specified package, which can then be displayed
  via :command:`feature_summary()`:

  .. code-block:: cmake

    set_package_info(<PackageName> <description> [<url> [<purpose>]])

  ``<PackageName>``
    Name of the package.

  ``<description>``
    A short description of the package.

  ``<url>``
    Homepage of the package.

  ``<purpose>``
    The purpose of the package.

  This command can be used either directly in the
  :ref:`Find module <Find Modules>` or in the project which uses the
  ``FeatureSummary`` module after the :command:`find_package()` call.  The
  features for which information can be set are added automatically by the
  ``find_package()`` command.

.. command:: set_feature_info

  .. deprecated:: 3.8

  Sets feature info for a package:

  .. code-block:: cmake

    set_feature_info(<name> <description> [<url>])

  Does the same as:

  .. code-block:: cmake

    set_package_info(<name> <description> [<url>])

.. command:: print_enabled_features

  .. deprecated:: 3.8

  Prints enabled features:

  .. code-block:: cmake

    print_enabled_features()

  Does the same as:

  .. code-block:: cmake

    feature_summary(WHAT ENABLED_FEATURES DESCRIPTION "Enabled features:")

.. command:: print_disabled_features

  .. deprecated:: 3.8

  Prints disabled features:

  .. code-block:: cmake

    print_disabled_features()

  Does the same as:

  .. code-block:: cmake

    feature_summary(WHAT DISABLED_FEATURES DESCRIPTION "Disabled features:")

Examples
^^^^^^^^

Example: Appending Feature Summary to a File
""""""""""""""""""""""""""""""""""""""""""""

In the following example, the feature summary output will be appended to
a specified file instead of printing:

.. code-block:: cmake

  include(FeatureSummary)
  feature_summary(WHAT ALL FILENAME ${CMAKE_BINARY_DIR}/all.log APPEND)

Example: Storing Feature Summary in a Variable
""""""""""""""""""""""""""""""""""""""""""""""

In the following example, the feature summary of enabled features is stored
in a specified variable ``enabledFeaturesText``, including the ``QUIET``
packages:

.. code-block:: cmake

  include(FeatureSummary)

  feature_summary(
    WHAT ENABLED_FEATURES
    INCLUDE_QUIET_PACKAGES
    DESCRIPTION "Enabled Features:"
    VAR enabledFeaturesText
  )

  message(STATUS "${enabledFeaturesText}")

Example: Adding a Custom Package Type
"""""""""""""""""""""""""""""""""""""

In the following example a custom package type is added and printed only
the categories that are not empty:

.. code-block:: cmake

  include(FeatureSummary)

  set_property(GLOBAL APPEND PROPERTY FeatureSummary_PKG_TYPES BUILD)

  find_package(FOO)
  set_package_properties(FOO PROPERTIES TYPE BUILD)

  feature_summary(
    WHAT BUILD_PACKAGES_FOUND
    DESCRIPTION "Build tools found:"
    QUIET_ON_EMPTY
  )

  feature_summary(
    WHAT BUILD_PACKAGES_NOT_FOUND
    DESCRIPTION "Build tools not found:"
    QUIET_ON_EMPTY
  )

Example: Setting Package Info
"""""""""""""""""""""""""""""

Example for setting the info for a package:

.. code-block:: cmake

  include(FeatureSummary)

  find_package(LibXml2)
  set_package_properties(
    LibXml2
    PROPERTIES
      DESCRIPTION "XML library"
      URL "http://xmlsoft.org"
  )
  # or
  set_package_properties(
    LibXml2
    PROPERTIES
      TYPE RECOMMENDED
      PURPOSE "Enables HTML-import in MyWordProcessor"
  )
  # or
  set_package_properties(
    LibXml2
    PROPERTIES
      TYPE OPTIONAL
      PURPOSE "Enables odt-export in MyWordProcessor"
  )

  find_package(DBUS)
  set_package_properties(
    DBUS
    PROPERTIES
      TYPE RUNTIME
      PURPOSE "Necessary to disable the screensaver during a presentation"
  )

Example: Printing Feature Summary
"""""""""""""""""""""""""""""""""

In the following example, this module is used to output feature summary at
the end of the configuration.  If any required package is not found,
processing stops with an error message at the end of the configuration
phase.

.. code-block:: cmake

  cmake_minimum_required(VERSION 3.15)
  project(Example)

  add_library(example example.c)

  include(FeatureSummary)

  find_package(CURL)
  set_package_properties(CURL PROPERTIES TYPE REQUIRED)
  target_link_libraries(example PRIVATE CURL::libcurl)

  find_package(LibXml2 QUIET)
  set_package_properties(LibXml2 PROPERTIES TYPE RECOMMENDED)
  if(LibXml2_FOUND)
    target_link_libraries(example PRIVATE LibXml2::LibXml2)
  endif()

  feature_summary(
    WHAT ALL
    INCLUDE_QUIET_PACKAGES
    DESCRIPTION "Feature summary:"
    FATAL_ON_MISSING_REQUIRED_PACKAGES
  )

Examples: Setting Feature Info
""""""""""""""""""""""""""""""

Example for setting the info for a feature:

.. code-block:: cmake

  include(FeatureSummary)

  option(WITH_FOO "Help for foo" ON)

  add_feature_info(Foo WITH_FOO "this feature provides very cool stuff")

Example for setting feature info based on a list of conditions:

.. code-block:: cmake

  include(FeatureSummary)

  option(WITH_FOO "Help for foo" ON)
  option(WITH_BAR "Help for bar" OFF)

  add_feature_info(
    FooBar
    "WITH_FOO;NOT WITH_BAR"
    "this feature is enabled when WITH_FOO is ON and WITH_BAR turned OFF"
  )

In the next example feature info are set depending on a full condition
syntax.  Unlike semicolon-separated list of conditions, this enables using
entire condition syntax as being the ``if`` clause argument:

.. code-block:: cmake

  include(FeatureSummary)

  option(WITH_FOO "Help for foo" ON)
  option(WITH_BAR "Help for bar" ON)
  option(WITH_BAZ "Help for baz" OFF)

  add_feature_info(
    FooBarBaz
    "WITH_FOO AND (WITH_BAR OR WITH_BAZ)"
    "this feature is enabled when the entire condition is true"
  )
#]=======================================================================]

get_property(_fsPkgTypeIsSet GLOBAL PROPERTY FeatureSummary_PKG_TYPES SET)
if(NOT _fsPkgTypeIsSet)
  set_property(GLOBAL PROPERTY FeatureSummary_PKG_TYPES RUNTIME OPTIONAL RECOMMENDED REQUIRED)
endif()

get_property(_fsReqPkgTypesIsSet GLOBAL PROPERTY FeatureSummary_REQUIRED_PKG_TYPES SET)
if(NOT _fsReqPkgTypesIsSet)
  set_property(GLOBAL PROPERTY FeatureSummary_REQUIRED_PKG_TYPES REQUIRED)
endif()

get_property(_fsDefaultPkgTypeIsSet GLOBAL PROPERTY FeatureSummary_DEFAULT_PKG_TYPE SET)
if(NOT _fsDefaultPkgTypeIsSet)
  set_property(GLOBAL PROPERTY FeatureSummary_DEFAULT_PKG_TYPE OPTIONAL)
endif()

function(_FS_GET_FEATURE_SUMMARY _property _var _includeQuiet)
  get_property(_fsPkgTypes GLOBAL PROPERTY FeatureSummary_PKG_TYPES)
  get_property(_fsDefaultPkgType GLOBAL PROPERTY FeatureSummary_DEFAULT_PKG_TYPE)

  set(_type "ANY")
  foreach(_fsPkgType ${_fsPkgTypes})
    if("${_property}" MATCHES "${_fsPkgType}_PACKAGES_(NOT_)?FOUND")
      set(_type "${_fsPkgType}")
      break()
    endif()
  endforeach()

  if("${_property}" MATCHES "PACKAGES_FOUND")
    set(_property "PACKAGES_FOUND")
  elseif("${_property}" MATCHES "PACKAGES_NOT_FOUND")
    set(_property "PACKAGES_NOT_FOUND")
  endif()


  set(_currentFeatureText "")
  get_property(_EnabledFeatures  GLOBAL PROPERTY ${_property})
  if(_EnabledFeatures)
    list(REMOVE_DUPLICATES _EnabledFeatures)
  endif()

  foreach(_currentFeature ${_EnabledFeatures})

    # does this package belong to the type we currently want to list ?
    get_property(_currentType  GLOBAL PROPERTY _CMAKE_${_currentFeature}_TYPE)
    if(NOT _currentType)
      list(FIND _fsPkgTypes "${_fsDefaultPkgType}" _defaultInPkgTypes)
      if("${_defaultInPkgTypes}" STREQUAL "-1")
        string(REGEX REPLACE ";([^;]+)$" " and \\1" _fsPkgTypes_msg "${_fsPkgTypes}")
        string(REPLACE ";" ", " _fsPkgTypes_msg "${_fsPkgTypes_msg}")
        message(FATAL_ERROR "Bad package property type ${_fsDefaultPkgType} used in global property FeatureSummary_DEFAULT_PKG_TYPE. "
                            "Valid types are ${_fsPkgTypes_msg}. "
                            "Either update FeatureSummary_DEFAULT_PKG_TYPE or add ${_fsDefaultPkgType} to the FeatureSummary_PKG_TYPES global property.")
      endif()
      set(_currentType ${_fsDefaultPkgType})
    endif()

    if("${_type}" STREQUAL ANY  OR  "${_type}" STREQUAL "${_currentType}")
      # check whether the current feature/package should be in the output depending on whether it was QUIET or not
      set(includeThisOne TRUE)
      set(_required FALSE)
      # skip QUIET packages, except if they are REQUIRED or INCLUDE_QUIET_PACKAGES has been set
      get_property(_fsReqPkgTypes GLOBAL PROPERTY FeatureSummary_REQUIRED_PKG_TYPES)
      foreach(_fsReqPkgType ${_fsReqPkgTypes})
        if("${_currentType}" STREQUAL "${_fsReqPkgType}")
          set(_required TRUE)
          break()
        endif()
      endforeach()
      if(NOT _required AND NOT _includeQuiet)
        get_property(_isQuiet  GLOBAL PROPERTY _CMAKE_${_currentFeature}_QUIET)
        if(_isQuiet)
          set(includeThisOne FALSE)
        endif()
      endif()
      get_property(_isTransitiveDepend
        GLOBAL PROPERTY _CMAKE_${_currentFeature}_TRANSITIVE_DEPENDENCY
      )
      if(_isTransitiveDepend)
        set(includeThisOne FALSE)
      endif()

      if(includeThisOne)

        string(APPEND _currentFeatureText "\n * ${_currentFeature}")
        get_property(_info  GLOBAL PROPERTY _CMAKE_${_currentFeature}_REQUIRED_VERSION)
        if(_info)
          string(APPEND _currentFeatureText " (required version ${_info})")
        endif()
        get_property(_info  GLOBAL PROPERTY _CMAKE_${_currentFeature}_DESCRIPTION)
        if(_info)
          string(APPEND _currentFeatureText ", ${_info}")
        endif()
        get_property(_info  GLOBAL PROPERTY _CMAKE_${_currentFeature}_URL)
        if(_info)
          string(APPEND _currentFeatureText ", <${_info}>")
        endif()

        get_property(_info  GLOBAL PROPERTY _CMAKE_${_currentFeature}_PURPOSE)
        foreach(_purpose ${_info})
          string(APPEND _currentFeatureText "\n   ${_purpose}")
        endforeach()

      endif()

    endif()

  endforeach()
  set(${_var} "${_currentFeatureText}" PARENT_SCOPE)
endfunction()

function(FEATURE_SUMMARY)
# cmake_parse_arguments(<prefix> <options> <one_value_keywords> <multi_value_keywords> args...)
  set(options APPEND
              INCLUDE_QUIET_PACKAGES
              FATAL_ON_MISSING_REQUIRED_PACKAGES
              QUIET_ON_EMPTY
              DEFAULT_DESCRIPTION)
  set(oneValueArgs FILENAME
                   VAR
                   DESCRIPTION)
  set(multiValueArgs WHAT)

  cmake_parse_arguments(_FS "${options}" "${oneValueArgs}" "${multiValueArgs}"  ${_FIRST_ARG} ${ARGN})

  if(_FS_UNPARSED_ARGUMENTS)
    message(FATAL_ERROR "Unknown keywords given to FEATURE_SUMMARY(): \"${_FS_UNPARSED_ARGUMENTS}\"")
  endif()

  if(NOT _FS_WHAT)
    message(FATAL_ERROR "The call to FEATURE_SUMMARY() doesn't set the required WHAT argument.")
  endif()

  if(_FS_DEFAULT_DESCRIPTION AND DEFINED _FS_DESCRIPTION)
    message(WARNING "DEFAULT_DESCRIPTION option discarded since DESCRIPTION is set.")
    set(_FS_DEFAULT_DESCRIPTION 0)
  endif()

  set(validWhatParts "ENABLED_FEATURES"
                     "DISABLED_FEATURES"
                     "PACKAGES_FOUND"
                     "PACKAGES_NOT_FOUND")

  get_property(_fsPkgTypes GLOBAL PROPERTY FeatureSummary_PKG_TYPES)
  get_property(_fsReqPkgTypes GLOBAL PROPERTY FeatureSummary_REQUIRED_PKG_TYPES)
  foreach(_fsPkgType ${_fsPkgTypes})
    list(APPEND validWhatParts "${_fsPkgType}_PACKAGES_FOUND"
                               "${_fsPkgType}_PACKAGES_NOT_FOUND")
  endforeach()

  set(title_ENABLED_FEATURES               "The following features have been enabled:")
  set(title_DISABLED_FEATURES              "The following features have been disabled:")
  set(title_PACKAGES_FOUND                 "The following packages have been found:")
  set(title_PACKAGES_NOT_FOUND             "The following packages have not been found:")
  foreach(_fsPkgType ${_fsPkgTypes})
    set(_fsPkgTypeDescription "${_fsPkgType} packages")
    get_property(_fsPkgTypeDescriptionIsSet GLOBAL PROPERTY FeatureSummary_${_fsPkgType}_DESCRIPTION SET)
    if(_fsPkgTypeDescriptionIsSet)
      get_property(_fsPkgTypeDescription GLOBAL PROPERTY FeatureSummary_${_fsPkgType}_DESCRIPTION )
    endif()
    set(title_${_fsPkgType}_PACKAGES_FOUND     "The following ${_fsPkgTypeDescription} have been found:")
    set(title_${_fsPkgType}_PACKAGES_NOT_FOUND "The following ${_fsPkgTypeDescription} have not been found:")
  endforeach()

  list(FIND validWhatParts "${_FS_WHAT}" indexInList)
  if(NOT "${indexInList}" STREQUAL "-1")
    _FS_GET_FEATURE_SUMMARY( ${_FS_WHAT} _featureSummary ${_FS_INCLUDE_QUIET_PACKAGES} )
    if(_featureSummary OR NOT _FS_QUIET_ON_EMPTY)
      if(_FS_DEFAULT_DESCRIPTION)
        set(_fullText "${title_${_FS_WHAT}}\n${_featureSummary}\n")
      else()
        set(_fullText "${_FS_DESCRIPTION}${_featureSummary}\n")
      endif()
    endif()

    if(_featureSummary)
      foreach(_fsReqPkgType ${_fsReqPkgTypes})
        if("${_FS_WHAT}" STREQUAL "${_fsReqPkgType}_PACKAGES_NOT_FOUND")
          set(requiredPackagesNotFound TRUE)
          break()
        endif()
      endforeach()
    endif()

  else()
    if("${_FS_WHAT}" STREQUAL "ALL")

      set(allWhatParts "ENABLED_FEATURES")
      foreach(_fsPkgType ${_fsPkgTypes})
        list(APPEND allWhatParts "${_fsPkgType}_PACKAGES_FOUND")
      endforeach()
      list(APPEND allWhatParts "DISABLED_FEATURES")
      foreach(_fsPkgType ${_fsPkgTypes})
        list(APPEND allWhatParts "${_fsPkgType}_PACKAGES_NOT_FOUND")
      endforeach()
    else()
      set(allWhatParts)
      foreach(part ${_FS_WHAT})
        list(FIND validWhatParts "${part}" indexInList)
        if(NOT "${indexInList}" STREQUAL "-1")
          list(APPEND allWhatParts "${part}")
        else()
          if("${part}" STREQUAL "ALL")
            message(FATAL_ERROR "The WHAT argument of FEATURE_SUMMARY() contains ALL, which cannot be combined with other values.")
          else()
            message(FATAL_ERROR "The WHAT argument of FEATURE_SUMMARY() contains ${part}, which is not a valid value.")
          endif()
        endif()
      endforeach()
    endif()

    set(_fullText "${_FS_DESCRIPTION}")
    foreach(part ${allWhatParts})
      set(_tmp)
      _FS_GET_FEATURE_SUMMARY( ${part} _tmp ${_FS_INCLUDE_QUIET_PACKAGES})
      if(_tmp)
        if(_fullText)
          string(APPEND _fullText "\n-- ")
        endif()
        string(APPEND _fullText "${title_${part}}\n${_tmp}\n")
        foreach(_fsReqPkgType ${_fsReqPkgTypes})
          if("${part}" STREQUAL "${_fsReqPkgType}_PACKAGES_NOT_FOUND")
            set(requiredPackagesNotFound TRUE)
            break()
          endif()
        endforeach()
      endif()
    endforeach()
  endif()

  if(_fullText OR NOT _FS_QUIET_ON_EMPTY)
    if(_FS_FILENAME)
      if(_FS_APPEND)
        file(APPEND "${_FS_FILENAME}" "${_fullText}")
      else()
        file(WRITE  "${_FS_FILENAME}" "${_fullText}")
      endif()

    else()
      if(NOT _FS_VAR)
        message(STATUS "${_fullText}")
      endif()
    endif()

    if(_FS_VAR)
      set(${_FS_VAR} "${_fullText}" PARENT_SCOPE)
    endif()
  endif()

  if(requiredPackagesNotFound  AND  _FS_FATAL_ON_MISSING_REQUIRED_PACKAGES)
    message(FATAL_ERROR "feature_summary() Error: REQUIRED package(s) are missing, aborting CMake run.")
  endif()
endfunction()

function(SET_PACKAGE_PROPERTIES _name _props)
  if(NOT "${_props}" STREQUAL "PROPERTIES")
    message(FATAL_ERROR "PROPERTIES keyword is missing in SET_PACKAGE_PROPERTIES() call.")
  endif()

  set(options ) # none
  set(oneValueArgs DESCRIPTION URL TYPE PURPOSE )
  set(multiValueArgs ) # none

  cmake_parse_arguments(_SPP "${options}" "${oneValueArgs}" "${multiValueArgs}"  ${ARGN})

  if(_SPP_UNPARSED_ARGUMENTS)
    message(FATAL_ERROR "Unknown keywords given to SET_PACKAGE_PROPERTIES(): \"${_SPP_UNPARSED_ARGUMENTS}\"")
  endif()

  if(_SPP_DESCRIPTION)
    get_property(_info  GLOBAL PROPERTY _CMAKE_${_name}_DESCRIPTION)
    if(_info AND NOT "${_info}" STREQUAL "${_SPP_DESCRIPTION}")
      message(STATUS "Warning: Property DESCRIPTION for package ${_name} already set to \"${_info}\", overriding it with \"${_SPP_DESCRIPTION}\"")
    endif()

    set_property(GLOBAL PROPERTY _CMAKE_${_name}_DESCRIPTION "${_SPP_DESCRIPTION}" )
  endif()

  if(_SPP_URL)
    get_property(_info  GLOBAL PROPERTY _CMAKE_${_name}_URL)
    if(_info AND NOT "${_info}" STREQUAL "${_SPP_URL}")
      message(STATUS "Warning: Property URL already set to \"${_info}\", overriding it with \"${_SPP_URL}\"")
    endif()

    set_property(GLOBAL PROPERTY _CMAKE_${_name}_URL "${_SPP_URL}" )
  endif()

  # handle the PURPOSE: use APPEND, since there can be multiple purposes for one package inside a project
  if(_SPP_PURPOSE)
    set_property(GLOBAL APPEND PROPERTY _CMAKE_${_name}_PURPOSE "${_SPP_PURPOSE}" )
  endif()

  get_property(_fsPkgTypes GLOBAL PROPERTY FeatureSummary_PKG_TYPES)
  get_property(_fsDefaultPkgType GLOBAL PROPERTY FeatureSummary_DEFAULT_PKG_TYPE)

  # handle the TYPE
  if(DEFINED _SPP_TYPE)
    # Supported types are listed in FeatureSummary_PKG_TYPES according to their priority
    get_property(_fsPkgTypes GLOBAL PROPERTY FeatureSummary_PKG_TYPES)
    list(FIND _fsPkgTypes ${_SPP_TYPE} _typeIndexInList)
    if("${_typeIndexInList}" STREQUAL "-1" )
      string(REGEX REPLACE ";([^;]+)$" " and \\1" _fsPkgTypes_msg "${_fsPkgTypes}")
      string(REPLACE ";" ", " _fsPkgTypes_msg "${_fsPkgTypes_msg}")
      message(FATAL_ERROR "Bad package property type ${_SPP_TYPE} used in SET_PACKAGE_PROPERTIES(). "
                          "Valid types are ${_fsPkgTypes_msg}." )
    endif()

    get_property(_previousType  GLOBAL PROPERTY _CMAKE_${_name}_TYPE)
    list(FIND _fsPkgTypes "${_previousType}" _prevTypeIndexInList)

    # make sure a previously set TYPE is not overridden with a lower new TYPE:
    if("${_typeIndexInList}" GREATER "${_prevTypeIndexInList}")
      set_property(GLOBAL PROPERTY _CMAKE_${_name}_TYPE "${_SPP_TYPE}" )
    endif()
  endif()
endfunction()

function(ADD_FEATURE_INFO _name _depends _desc)
  cmake_policy(GET CMP0183 _CDO_CMP0183
    PARENT_SCOPE # undocumented, do not use outside of CMake
  )
  set(_enabled 1)
  if("x${_CDO_CMP0183}x" STREQUAL "xNEWx")
    foreach(_d ${_depends})
      cmake_language(EVAL CODE "
        if(${_d})
        else()
          set(_enabled 0)
        endif()"
      )
    endforeach()
  else()
    foreach(_d ${_depends})
      string(REGEX REPLACE " +" ";" _d "${_d}")
      if(${_d})
      else()
        set(_enabled 0)
        break()
      endif()
    endforeach()
  endif()
  if (${_enabled})
    set_property(GLOBAL APPEND PROPERTY ENABLED_FEATURES "${_name}")
  else ()
    set_property(GLOBAL APPEND PROPERTY DISABLED_FEATURES "${_name}")
  endif ()

  set_property(GLOBAL PROPERTY _CMAKE_${_name}_DESCRIPTION "${_desc}" )

  if("x${_CDO_CMP0183}x" STREQUAL "xx" AND "x${_depends}x" MATCHES "[^A-Za-z0-9_.; ]")
    cmake_policy(GET_WARNING CMP0183 _CDO_CMP0183_WARNING)
    message(AUTHOR_WARNING "${_CDO_CMP0183_WARNING}")
  endif()
  unset(_CDO_CMP0183)
endfunction()

# The stuff below is only kept for compatibility

function(SET_PACKAGE_INFO _name _desc)
  message(DEPRECATION "SET_PACKAGE_INFO is deprecated. Use SET_PACKAGE_PROPERTIES instead.")
  unset(_url)
  unset(_purpose)
  if(ARGC GREATER 2)
    set(_url "${ARGV2}")
  endif()
  if(ARGC GREATER 3)
    set(_purpose "${ARGV3}")
  endif()
  set_property(GLOBAL PROPERTY _CMAKE_${_name}_DESCRIPTION "${_desc}" )
  if(NOT _url STREQUAL "")
    set_property(GLOBAL PROPERTY _CMAKE_${_name}_URL "${_url}" )
  endif()
  if(NOT _purpose STREQUAL "")
    set_property(GLOBAL APPEND PROPERTY _CMAKE_${_name}_PURPOSE "${_purpose}" )
  endif()
endfunction()

function(SET_FEATURE_INFO)
  message(DEPRECATION "SET_FEATURE_INFO is deprecated. Use ADD_FEATURE_INFO instead.")
  set_package_info(${ARGN})
endfunction()

function(PRINT_ENABLED_FEATURES)
  message(DEPRECATION "PRINT_ENABLED_FEATURES is deprecated. Use
    feature_summary(WHAT ENABLED_FEATURES DESCRIPTION \"Enabled features:\")")
  feature_summary(WHAT ENABLED_FEATURES  DESCRIPTION "Enabled features:")
endfunction()

function(PRINT_DISABLED_FEATURES)
  message(DEPRECATION "PRINT_DISABLED_FEATURES is deprecated. Use
    feature_summary(WHAT DISABLED_FEATURES DESCRIPTION \"Disabled features:\")")
  feature_summary(WHAT DISABLED_FEATURES  DESCRIPTION "Disabled features:")
endfunction()