CMake 3.17 Release Notes
************************

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Changes made since CMake 3.16 include the following.

New Features
============

Generators
----------

* :manual:`cmake(1)` gained a :generator:`Ninja Multi-Config` generator,
  which is similar to the :generator:`Ninja` generator but can be used to build
  multiple configurations at once.

* :ref:`Visual Studio Generators` learned to support per-config sources.
  Previously only :ref:`Command-Line Build Tool Generators` supported them.

* :ref:`Visual Studio Generators` for VS 2010 and above now support
  specifying the ``VCTargetsPath`` value for project files in
  :variable:`CMAKE_GENERATOR_TOOLSET` setting.

* :ref:`Visual Studio Generators` for VS 2010 and above learned to
  support .NET Standard and .NET Core.  See the
  :prop_tgt:`DOTNET_TARGET_FRAMEWORK` target property and
  associated :variable:`CMAKE_DOTNET_TARGET_FRAMEWORK` variable.

Languages
---------

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  now offers meta-features for the CUDA language standard levels
  (e.g. ``cuda_std_03``, ``cuda_std_14``).  See
  :prop_gbl:`CMAKE_CUDA_KNOWN_FEATURES`.

Compilers
---------

* The IBM XL Fortran compiler is now supported by the :generator:`Ninja`
  generator.

Command-Line
------------

* :manual:`cmake(1)` gained a ``--debug-find`` command-line option to
  enable additional human-readable output on where find commands search.

* :manual:`cmake(1)` gained a ``--trace-format`` command-line option that
  can be used to set the ``--trace`` output format. Currently, the old
  human readable and the new JSON format are supported. The new JSON format
  is easier to parse automatically, than the existing format.

* :manual:`cmake(1)` gained a ``-E rm`` command-line tool that can be
  used to remove directories and files.  This supersedes the existing
  ``-E remove`` and ``-E remove_directory`` tools and has better semantics.

Commands
--------

* The :command:`add_custom_command` command learned to interpret paths in
  ``DEPENDS`` arguments that are specified relative to the current
  binary directory.

* The :command:`foreach` learned a new option ``ZIP_LISTS`` to iterate
  over multiple lists simultaneously.

* The :command:`load_cache(READ_WITH_PREFIX)` command mode is now allowed
  when using ``cmake -P`` to :ref:`Run a Script <Script Processing Mode>`.

* The :command:`message` command learned to output context provided in
  the :variable:`CMAKE_MESSAGE_CONTEXT` variable for log levels
  ``NOTICE`` and below.  Enable this output with the new ``--log-context``
  command-line option or :variable:`CMAKE_MESSAGE_CONTEXT_SHOW` variable.

* The :command:`message` command gained new keywords ``CHECK_START``,
  ``CHECK_PASS`` and ``CHECK_FAIL``.

* :command:`target_compile_options` command now honors the ``BEFORE``
  keyword more consistently.  See policy :policy:`CMP0101`.

Variables
---------

* A :variable:`CMAKE_CTEST_ARGUMENTS` variable was added to specify a list
  of command-line arguments passed to CTest when running through the
  ``test`` (or ``RUN_TESTS``) target of the generated build system.

* The following variables are now defined inside a :command:`function`:

  - :variable:`CMAKE_CURRENT_FUNCTION`
  - :variable:`CMAKE_CURRENT_FUNCTION_LIST_DIR`
  - :variable:`CMAKE_CURRENT_FUNCTION_LIST_FILE`
  - :variable:`CMAKE_CURRENT_FUNCTION_LIST_LINE`

* The :variable:`CMAKE_CUDA_RUNTIME_LIBRARY` variable and
  :prop_tgt:`CUDA_RUNTIME_LIBRARY` target property were introduced to
  select the CUDA runtime library used when linking targets that
  use CUDA.

* The :variable:`CMAKE_FIND_DEBUG_MODE` variable was introduced to
  print extra find call information during the cmake run to standard
  error. Output is designed for human consumption and not for parsing.

* The :variable:`CMAKE_EXPORT_COMPILE_COMMANDS` variable now takes its
  initial value from the :envvar:`CMAKE_EXPORT_COMPILE_COMMANDS` environment
  variable if no explicit configuration is given.

* The :variable:`CMAKE_<LANG>_COMPILER_LAUNCHER` variable, if not set
  explicitly, now takes its initial value from the
  :envvar:`CMAKE_<LANG>_COMPILER_LAUNCHER` environment variable.

* The :variable:`CMAKE_MESSAGE_LOG_LEVEL` variable can now be used
  to persist a log level between CMake runs, unlike the ``--log-level``
  command line option which only applies to that particular run.

* The :variable:`CMAKE_XCODE_SCHEME_ENVIRONMENT` variable and
  :prop_tgt:`XCODE_SCHEME_ENVIRONMENT` target property were added to
  tell the :generator:`Xcode` generator to set the value of the
  ``Custom Working Directory`` schema option.

Properties
----------

* The :prop_tgt:`AIX_EXPORT_ALL_SYMBOLS` target property and associated
  :variable:`CMAKE_AIX_EXPORT_ALL_SYMBOLS` variable were created to
  optionally explicitly disbale automatic export of symbols from shared
  libraries on AIX.

* The :prop_tgt:`DEPRECATION` target property was added to mark
  a target as deprecated.  If a linked target is marked as
  deprecated, a warning with the deprecation message is issued
  at generate time.

* The :prop_tgt:`INSTALL_NAME_DIR` target property now supports
  :manual:`generator expressions <cmake-generator-expressions(7)>`.
  In particular, the ``$<INSTALL_PREFIX>`` generator expression can
  be used to set the directory relative to the install-time prefix.

* Target properties :prop_tgt:`OSX_COMPATIBILITY_VERSION` and
  :prop_tgt:`OSX_CURRENT_VERSION` were added to set the
  ``compatibility_version`` and ``curent_version`` respectively
  on macOS. For backwards compatibility, if these properties
  are not set, :prop_tgt:`SOVERSION` and :prop_tgt:`VERSION`
  are used respectively as fallbacks.

* The :prop_tgt:`VS_DOTNET_DOCUMENTATION_FILE` target property was added
  to tell :ref:`Visual Studio Generators` to generate a ``DocumentationFile``
  reference in ``.csproj`` files.

Modules
-------

* The :module:`ExternalProject` module :command:`ExternalProject_Add`
  command gained a ``GIT_SUBMODULES_RECURSE`` option to specify whether
  Git submodules should be updated recursively.  The default is on to
  preserve existing behavior.

* The :module:`FindCUDAToolkit` module was added to find the
  CUDA Toolkit without enabling CUDA as a language.

* The :module:`FindCURL` module learned to find CURL using
  the ``CURLConfig.cmake`` package configuration file generated by
  CURL's cmake buildsystem.  It also gained a new ``CURL_NO_CURL_CMAKE``
  option to disable this behavior.

* The :module:`FindFLEX` module's ``FLEX_TARGET`` command now runs ``flex``
  with :variable:`CMAKE_CURRENT_BINARY_DIR` as the working directory.
  See policy :policy:`CMP0098`.

* The :module:`FindLibArchive` module now provides an imported target
  for libarchive.

* The :module:`FindPython` module has learned to find Python components
  in active virtual environments managed by ``conda``.

* The :module:`FindPython3` and :module:`FindPython` modules gained,
  respectively, variable ``Python3_SOABI`` and ``Python_SOABI`` giving
  the standard extension suffix for modules.

* The :module:`FindLibXml2` module now provides an imported target for the
  ``xmllint`` executable

Autogen
-------

* :prop_tgt:`AUTOMOC` and :prop_tgt:`AUTOUIC` learned to process headers
  with a ``.hh`` extension.  See policy :policy:`CMP0100`.

CTest
-----

* The :variable:`CTEST_CONFIGURATION_TYPE` variable is now set from the
  command line when :manual:`ctest(1)` is invoked with ``-C <cfg>``.

* The :manual:`ctest(1)` gained support for Dr. Memory to run
  memcheck runs.

* The :manual:`ctest(1)` tool gained a ``--no-tests=<[error|ignore]>`` option
  to explicitly set and unify the behavior between direct invocation and
  script mode if no tests were found.

* The :manual:`ctest(1)` tool gained a ``--repeat <mode>:<n>`` option
  to specify conditions in which to repeat tests.  This generalizes
  the existing ``--repeat-until-fail <n>`` option to add modes for
  ``until-pass`` and ``after-timeout``.

* The :command:`ctest_test` command gained a ``REPEAT <mode>:<n>`` option
  to specify conditions in which to repeat tests.

CPack
-----

* The :cpack_gen:`CPack DragNDrop Generator` learned to use
  the :variable:`CPACK_DMG_<component>_FILE_NAME` variable
  to set a custom filename when packaging components into
  their own DMGs.

* The :cpack_gen:`CPack DragNDrop Generator` learned to handle
  RTF formatted license files.  When :variable:`CPACK_DMG_SLA_DIR`
  variable is set, ``<language>.license.rtf`` is considered, but
  only as a fallback when the plaintext (``.txt``) file is not found
  in order to maintain backwards compatibility.

* The :cpack_gen:`CPack NSIS Generator` gained a new variable
  :variable:`CPACK_NSIS_MUI_HEADERIMAGE` to set the header image.
  To not break existing setups, it still defaults to
  :variable:`CPACK_PACKAGE_ICON` if the new variable is not set.

* The :cpack_gen:`CPack NSIS Generator` now supports
  :variable:`CPACK_NSIS_UNINSTALL_NAME`.
  This can be used to specify the name of the Uninstall program.

* The :cpack_gen:`CPack NSIS Generator` now supports
  :variable:`CPACK_NSIS_WELCOME_TITLE` and
  :variable:`CPACK_NSIS_WELCOME_TITLE_3LINES`.
  These can be used to specify the welcome page title and display it in 3 lines.

* The :cpack_gen:`CPack NSIS Generator` now supports
  :variable:`CPACK_NSIS_FINISH_TITLE` and
  :variable:`CPACK_NSIS_FINISH_TITLE_3LINES`.
  These can be used to specify the finish page title and display it in 3 lines.

* The :cpack_gen:`CPack productbuild Generator` gained option
  :variable:`CPACK_PRODUCTBUILD_BACKGROUND` to specify a background image
  for the macOS installer.

Other
-----

* :manual:`ccmake(1)` now displays cache values using colors
  based on the entry type if the terminal supports color.

* :manual:`ccmake(1)` now displays messages and a progress bar during
  configure and generate.  It will keep the output displayed if any
  errors or warnings occurred.

Deprecated and Removed Features
===============================

* An explicit deprecation diagnostic was added for policy ``CMP0068``
  and policy ``CMP0069`` (``CMP0067`` and below were already deprecated).
  The :manual:`cmake-policies(7)` manual explains that the OLD behaviors
  of all policies are deprecated and that projects should port to the
  NEW behaviors.

* The :cpack_gen:`CPack PackageMaker Generator` generator has been
  deprecated because Xcode no longer distributes the PackageMaker tools.
  The undocumented ``OSXX11`` generator has also been deprecated.

* The :manual:`cmake(1)` command-line ``-E remove`` and ``-E remove_directory``
  tools are deprecated in favor of the new ``-E rm`` tool.  The older tools
  always returned 0 if a named path did not exist even without the force
  option and cannot be fixed without breaking compatibility, and so have
  been superseded.

Other Changes
=============

* The :manual:`file API <cmake-file-api(7)>` index file now emits a
  ``multiConfig`` flag specifying whether or not the generator supports
  multiple output configurations.

* Target link properties :prop_tgt:`INTERFACE_LINK_OPTIONS`,
  :prop_tgt:`INTERFACE_LINK_DIRECTORIES` and
  :prop_tgt:`INTERFACE_LINK_DEPENDS` are now transitive over private
  dependencies on static libraries.
  See policy :policy:`CMP0099`.

* When using MinGW tools, the :command:`find_library` command no longer
  finds ``.dll`` files by default.  Instead it expects ``.dll.a`` import
  libraries to be available.

* The :generator:`MinGW Makefiles` generator no longer issues an error if
  ``sh.exe`` is present in the environment's ``PATH``.

* The :generator:`Ninja` generator now prefers the first ninja build
  tool to appear in the ``PATH`` no matter whether it is called
  ``ninja-build``, ``ninja``, or ``samu``.  Previously the first
  of those names to appear anywhere in the ``PATH`` would be preferred.

* With SDCC the ``sdar`` tool is now preferred over ``sdcclib`` as librarian.
  The latter was deprecated by SDCC 3.2.0 and removed in SDCC 3.8.6.

* With SDCC the default flags no longer include any target-specific flags.
  Previously the default flags were hard-coded for 8051.

* The :variable:`CMAKE_VS_GLOBALS` variable value now applies during
  compiler identification and in targets created by the
  :command:`add_custom_target` command.

* The :generator:`Xcode` generator no longer hard-codes ``-Wmost``,
  ``-Wno-four-char-constants``, and ``-Wno-unknown-pragmas`` warning flags.