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` command learned a new ``ZIP_LISTS`` option 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``.

* The :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 was added
  to initialize the :prop_tgt:`XCODE_SCHEME_ENVIRONMENT` target property.

* The :variable:`CMAKE_XCODE_SCHEME_WORKING_DIRECTORY` variable and
  associated :prop_tgt:`XCODE_SCHEME_WORKING_DIRECTORY` 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 disable 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:`MACHO_COMPATIBILITY_VERSION` and
  :prop_tgt:`MACHO_CURRENT_VERSION` were added to set the
  ``compatibility_version`` and ``curent_version``, respectively,
  for Mach-O binaries.  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. Moreover, commands
  ``Python3_add_library()`` and ``Python_add_library()`` gained the option
  ``WITH_SOABI`` to prefix the library suffix with the value of ``SOABI``.

* 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)` tool 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 support for a
  :variable:`CPACK_PRODUCTBUILD_BACKGROUND` variable 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 ``PackageMaker`` 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.

* The :cpack_gen:`CPack NSIS Generator` now requires NSIS 3.0 or later.

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.

Updates
=======

Changes made since CMake 3.17.0 include the following.

3.17.1
------

* CMake 3.17.0 updated the :cpack_gen:`CPack NSIS Generator` with changes
  that require NSIS 3.0 or later.  CMake 3.17.1 now enforces the use
  of a sufficiently new version.

3.17.3
------

* Selection of the Objective C or C++ compiler now considers the
  :envvar:`CC` or :envvar:`CXX` environment variable if the
  :envvar:`OBJC` or :envvar:`OBJCXX` environment variable is not set.

* The :module:`FindPkgConfig` module now extracts include directories
  prefixed with ``-isystem`` into the ``*_INCLUDE_DIRS`` variables and
  :prop_tgt:`INTERFACE_INCLUDE_DIRECTORIES` target properties.
  Previously they would be places in ``*_CFLAGS_OTHER`` variables and
  :prop_tgt:`INTERFACE_COMPILE_OPTIONS` target properties.

3.17.5
------

* The default value of :variable:`CMAKE_AUTOMOC_PATH_PREFIX` was changed to
  ``OFF`` because this feature can break existing projects that have
  identically named header files in different include directories.
  This restores compatibility with behavior of CMake 3.15 and below.
  The default was also changed to ``OFF`` in 3.16.9.
