CMake 4.4 Release Notes
***********************

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Changes made since CMake 4.3 include the following.

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

Diagnostics
-----------

* CMake diagnostic actions are now tracked in a new state type managed by the
  :command:`cmake_diagnostic` command.  This replaces the old system which
  sometimes used variables to manage reporting actions and sometimes did not
  allow management beyond command-line options and presets.  The new system
  also introduces several new diagnostic categories and significantly reduces
  the cost of adding additional categories in the future.  See the
  :manual:`cmake-diagnostics(7)` manual for a list of available categories.

* The :diagnostic:`CMD_INSTALL_ABSOLUTE_DESTINATION` diagnostic category
  was added to diagnose :command:`install` commands that specify an
  absolute ``DESTINATION``.  This diagnostic may be controlled with the
  :option:`-Winstall-absolute-destination <cmake -W>` command-line option,
  the ``installAbsoluteDestination`` field in a
  :manual:`CMake Presets <cmake-presets(7)>`
  :preset:`configurePresets.warnings` object,
  or the :command:`cmake_diagnostic` command.

Presets
-------

* :manual:`cmake-presets(7)` files now support schema version 12.

* :manual:`cmake(1)`, :manual:`ctest(1)`, and :manual:`cpack(1)` gained
  ``--presets-file`` arguments to support loading
  :manual:`presets <cmake-presets(7)>` from the specified file instead of
  ``CMakePresets.json`` and/or ``CMakeUserPresets.json``. See
  :option:`cmake --presets-file`,
  :option:`cmake --build --presets-file <cmake--build --presets-file>`,
  :option:`cmake --workflow --presets-file <cmake--workflow --presets-file>`,
  :option:`ctest --presets-file`, and :option:`cpack --presets-file` for details.

* :manual:`cmake-presets(7)`, in schema version 12 and above, now expand the
  :ref:`${fileDir} <CMakePresets fileDir>` macro to the directory of the
  presets file containing the ``${fileDir}`` macro, regardless of whether
  it is inherited by another preset in a different directory.

* :manual:`cmake-presets(7)` gained support for a
  ``testPassthroughArguments`` field in the
  test preset ``execution`` object for
  forwarding arguments to test executables via presets.

File-Based API
--------------

* The :manual:`cmake-file-api(7)` "codemodel" version 2 object has been
  updated to 2.11.

* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" object's
  "sources" and "interfaceSources" objects gained new ``fileSetIndexes`` fields
  to support sources belonging to multiple file sets. The ``fileSetIndex``
  fields are maintained for backwards compatibility only, and users are advised
  to port to the new fields.

* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" object's
  "sources" object gained a new ``backtraces`` field to represent multiple
  command invocations which associate a single source for a given target with
  multiple file sets. The ``backtrace`` field is maintained for backwards
  compatibility only, and users are advised to port to the new field.

* The :manual:`cmake-file-api(7)` "codemodel" version 2 "installers" object's
  optional ``fileSetType`` field gained a new ``SOURCES`` value to incorporate
  the new ``SOURCES`` :ref:`file set <file sets>` type in codemodel replies.

Instrumentation
---------------

* The :manual:`cmake-instrumentation(7)` data version has been updated to 1.1.
* :manual:`cmake-instrumentation(7)` gained a ``captureOutput`` option which
  collects the ``stdout`` and ``stderr`` of instrumented commands.
* :manual:`cmake-instrumentation(7)` gained a ``compileTrace`` option which
  records compiler-generated trace files (e.g., from Clang's ``-ftime-trace``
  flag).

Generators
----------

* The :ref:`Ninja Generators` now support generating a build target named
  ``test_prep/<test-name>`` for each test added by :command:`add_test`, which
  builds all dependencies for that test. Build dependencies are registered for
  an executable target invoked by the test, targets referenced in generator
  expressions in the test command, and explicit dependencies added using the
  new ``BUILD_DEPENDS`` option. This behavior is enabled by the new
  :variable:`CMAKE_TEST_BUILD_DEPENDS` variable. A ``test_prep/all``
  target is also generated to depend on every ``test_prep/<test-name>``
  target. Tests with names that are not valid target names are excluded from
  this behavior. If multiple tests in different directories share the same
  name, their dependencies are merged into one ``test_prep/<test-name>``
  target.

Languages
---------

* CUDA language level 23 (corresponding to C++ 23) is now supported with
  NVCC 13.3 and above.

Compilers
---------

* C++ 20 named modules are now supported with ``clang-cl``.
  See :manual:`cmake-cxxmodules(7)`.

* The ``ibm-flang`` compiler is now supported with
  :variable:`compiler id <CMAKE_<LANG>_COMPILER_ID>` ``IBMFlang``.

* The `Pelles C`_ toolchain is now supported with
  :variable:`compiler id <CMAKE_<LANG>_COMPILER_ID>` ``PellesC``.

  The ``ASM_POASM`` language was added to support the Pelles Macro Assembler.

* The Open Watcom ``wlink`` linker is now identified with
  :variable:`CMAKE_<LANG>_COMPILER_LINKER_ID` ``OpenWatcom``.

* The `wild linker <https://github.com/wild-linker/wild>`_ is now
  supported with :variable:`CMAKE_<LANG>_COMPILER_LINKER_ID` ``WILD``.

.. _`Pelles C`: https://pellesc.se

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

* :manual:`cmake(1)` now supports ``--build <dir> --preset <pre>``
  regardless of the current working directory.

* The :option:`cmake -D` command-line option now populates a
  default :prop_cache:`HELPSTRING` for variables known to CMake.

* :option:`cmake --install` now supports installing multiple components.

* :option:`cmake --install` now accepts ``-j<N>`` in addition to ``-j <N>``
  for specifying the number of parallel jobs.

* The :option:`cmake -E` commands
  :option:`copy_if_different <cmake-E copy_if_different>`,
  :option:`copy_if_newer <cmake-E copy_if_newer>`,
  :option:`copy_directory <cmake-E copy_directory>`,
  :option:`copy_directory_if_different <cmake-E copy_directory_if_different>`,
  and :option:`copy_directory_if_newer <cmake-E copy_directory_if_newer>`
  gained support for the ``-t`` argument.

* The :option:`cmake -E tar <cmake-E tar>` command-line tool gained the
  :option:`--cmake-tar-encoding <cmake-E_tar --cmake-tar-encoding>` flag
  to specify the pathname encoding used in archives.

Commands
--------

* The :command:`block` command can now create a ``DIAGNOSTICS`` scope.

* The :command:`cmake_diagnostic` command was added to manipulate CMake's
  diagnostic state.

* The :command:`cmake_parse_arguments` command gained a new ``PARSE_ARGN``
  signature that starts parsing after the last named argument of the calling
  function and works exactly like ``PARSE_ARGV`` with ``<N>`` being the number
  of parameters in the function definition.

* The :command:`discover_tests` command was added to support registering tests
  discovered at test time by :manual:`ctest(1)`. It runs a user-provided
  discovery command, parses its output, and generates test names, arguments,
  and properties from regular-expression captures.

* The :command:`execute_process` command gained
  ``ENVIRONMENT`` and ``ENVIRONMENT_MODIFICATION`` options to run child
  processes with a modified environment.

* The :command:`file(ARCHIVE_CREATE)` and :command:`file(ARCHIVE_EXTRACT)`
  commands gained an ``ENCODING`` option to specify the encoding of the
  archive pathnames.  The default is now ``UTF-8``.
  See policy :policy:`CMP0213`.

* The :command:`file(READ_SYMLINK)` command gained a ``RESULT``
  option to capture errors without failing.

* The :command:`include` command now has a ``NO_DIAGNOSTIC_SCOPE`` option.

* The :command:`list(FILTER)` command gained a new ``PREDICATE`` mode
  that invokes a user-defined :command:`function` to decide which elements are
  included or excluded, complementing the existing ``REGEX`` mode.

* The :command:`list(SORT)` command gained a new ``COMPARATOR`` keyword
  that invokes a user-defined :command:`function` to compare elements, complementing
  the built-in ``COMPARE`` methods.

* The :command:`list(TRANSFORM)` command gained a new ``APPLY`` action that
  invokes a user-defined :command:`function` for each element of the list,
  enabling arbitrary per-element transformations.

* The :command:`list(TRANSFORM)` command gained a new ``PREDICATE`` selector
  that invokes a user-defined :command:`function` to decide which elements are
  transformed.

* The :command:`string(JSON ... PARTIAL_EQUAL) <string(JSON-PARTIAL_EQUAL)>`
  command was added to compare two JSON values using *partial* equality.

File Sets
---------

* A ``SOURCES`` :ref:`file set <file sets>` type was added to specify
  a target's source files via file sets.

* The :prop_fs:`CXX_SCAN_FOR_MODULES` file set property was added to
  control whether a file set's sources are scanned for C++ modules.

* The :prop_fs:`INDEPENDENT_FILES` file set property was added to
  specify that a file set's sources do not depend on any generated files.

* The :prop_fs:`JOB_POOL_COMPILE` file set property was added to
  assign a file set's sources to a specific Ninja job pool.

* The :prop_fs:`SCOPE`, :prop_fs:`TYPE`, :prop_fs:`BASE_DIRS`,
  :prop_fs:`SOURCES`, and :prop_fs:`INTERFACE_SOURCES` file set
  properties were added to provide the declared details of a file set.

* The :prop_fs:`SKIP_LINTING` file set property was added to exclude
  a file set's sources from target-wide code checks.

* The :prop_fs:`SKIP_PRECOMPILE_HEADERS` file set property was added
  to avoid using precompiled headers for a file set's sources.

* The :prop_fs:`SKIP_UNITY_BUILD_INCLUSION` file set property was added
  to exclude a file set's sources from inclusion in unity builds.

Variables
---------

* The :variable:`CMAKE_INSTALL_DEFAULT_COMPONENT_NAME` variable gained
  support for a special ``<PROJECT_NAME>`` placeholder value.
  It tells each :command:`install` invocation to take a default component
  name from the current :variable:`PROJECT_NAME` variable value.

Environment Variables
---------------------

* The :envvar:`CMAKE_DISABLE_PRECOMPILE_HEADERS` environment variable
  was added to disable precompiled headers by default.

Properties
----------

* The :prop_tgt:`VERIFY_INTERFACE_HEADER_SETS` and
  :prop_tgt:`VERIFY_PRIVATE_HEADER_SETS` target properties now always
  create the per-target verification target and the aggregate
  ``all_verify_interface_header_sets``, ``all_verify_private_header_sets``,
  and ``all_verify_header_sets`` targets when the property is enabled,
  even if the target has no matching header sets.

* The :prop_tgt:`VERIFY_INTERFACE_HEADER_SETS` and
  :prop_tgt:`VERIFY_PRIVATE_HEADER_SETS` target properties now support
  ``OBJC`` and ``OBJCXX`` languages in addition to ``C`` and ``CXX``.

* The :prop_tgt:`VS_SOLUTION_DEPLOY` target property is now implemented
  for targets created by :command:`add_custom_target`.

Modules
-------

* The :module:`CMakePackageConfigHelpers` module's
  :command:`write_basic_package_version_file` command now supports
  ``SamePatchVersion``, ``SameFullVersion``, and ``SemanticVersion``
  compatibility modes. The older ``ExactVersion`` mode is now documented as
  deprecated in favor of the more explicit ``SamePatchVersion`` and
  ``SameFullVersion`` modes. The ``SemanticVersion`` mode treats ``0.y.z``
  versions more strictly than ``1.y.z`` and later versions.

* The :module:`ExternalData` module gained an
  :variable:`ExternalData_LINK_MODE` variable to select an ordered list
  of file materialization modes for hard links, symbolic links, and
  copies.

* The :module:`ExternalData` module gained an
  :variable:`ExternalData_STATE_ROOT` variable to store hash records outside
  :variable:`ExternalData_BINARY_ROOT`.

* The :module:`ExternalProject` and :module:`FetchContent` modules gained
  :variable:`CMAKE_EP_GIT_CLONE_RETRY_COUNT` and
  :variable:`CMAKE_EP_GIT_CLONE_RETRY_DELAY` variables to control
  ``git clone`` retries.

* The :module:`FindCUDAToolkit` module now creates a ``CUDA::sanitizer``
  target for the :ref:`compute-sanitizer <FindCUDAToolkit_sanitizer>`
  library.

* The :module:`FindCUDAToolkit` module now provides an imported target
  for ``cufilt`` in CUDA 11.4 and above.

* :module:`FindPython` and :module:`FindPython3` modules gained the support of
  the Stable ABI for Free Threaded Python (``SABIT``) as specified by
  :pep:`803`.

Generator Expressions
---------------------

* The :genex:`TARGET_OBJECTS` generator expression now has an optional
  ``SOURCE_FILES:...`` argument, which can take one or more source files as
  arguments, and will filter its output to only include objects built from
  those source files.

Swift
-----

* The :ref:`Ninja Generators` gained the
  :prop_tgt:`Swift_SEPARATE_MODULE_EMISSION` target property, initialized by
  the :variable:`CMAKE_Swift_SEPARATE_MODULE_EMISSION` variable, to control
  whether importable Swift targets emit ``.swiftmodule`` from a dedicated
  build edge.  Policy :policy:`CMP0215` enables this by default.

* The default :prop_tgt:`Swift_MODULE_NAME` now replaces hyphens with
  underscores, since hyphens are not valid in Swift module identifiers.

* Swift targets now have a package name by default.
  See policy :policy:`CMP0216`.

* The :prop_tgt:`Swift_PACKAGE_NAME` target property was added to
  specify a Swift package name.

* Swift targets on Windows now support the ``$<TARGET_PDB_FILE:...>``
  family of generator expressions.

CTest
-----

* :manual:`ctest(1)` gained support for forwarding extra arguments to test
  executables using a :option:`-- <ctest -->` separator.

* :manual:`ctest(1)` gained a :ref:`CoverageTool <ctest-CoverageTool>`
  option in :ref:`Dashboard Client` mode to configure tests for
  coverage collection by ``llvm-cov``.

* The :command:`ctest_configure`, :command:`ctest_build`,
  :command:`ctest_test`, and :command:`ctest_memcheck` commands gained
  ``PRESET`` and ``PRESETS_FILE`` arguments to support using
  :manual:`presets <cmake-presets(7)>` for their :ref:`Dashboard Client` steps.

  The :variable:`CTEST_CONFIGURE_PRESET`, :variable:`CTEST_BUILD_PRESET`,
  :variable:`CTEST_TEST_PRESET`, :variable:`CTEST_PRESET`, and
  :variable:`CTEST_PRESETS_FILE` variables may be used to specify preset
  arguments to the above commands in a :ref:`Dashboard Client` script or
  on the :program:`ctest` command line via the
  :ctest-dashboard-option:`-D` option.

* :manual:`ctest(1)` gained support for a :variable:`CTEST_SUBMIT_PARTS`
  variable that restricts which parts are uploaded when operating in
  :ref:`Dashboard Client` mode.

* The :command:`ctest_update` command gained ``VERSION_ONLY`` and
  ``VERSION_OVERRIDE`` options to select or report a source revision
  without requiring the corresponding
  :variable:`CTEST_UPDATE_VERSION_ONLY` or
  :variable:`CTEST_UPDATE_VERSION_OVERRIDE` dashboard script variables.

CPack
-----

* The :cpack_gen:`CPack Archive Generator` gained the
  :variable:`CPACK_ARCHIVE_ENCODING` variable to specify the pathname
  encoding used in package archives.

* The :cpack_gen:`CPack NSIS Generator` gained a new variable
  :variable:`CPACK_NSIS_IGNORE_COMPONENTS_PAGE` to ignore the
  component selection page in the installer.

* The :variable:`CPACK_RPM_SPEC_MORE_DEFINE` variable now supports
  a list of definitions.

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

* The ``-W[no-][error=]dev`` command-line options are deprecated.  The new
  spelling is :option:`-W[no-][error=]author <cmake -W>`.

* The ``--warn-uninitialized`` command-line option is deprecated.  The new
  spelling is :option:`-Wuninitialized <cmake -W>`.

* The ``--no-warn-unused-cli`` command-line option is deprecated.  The new
  spelling is :option:`-Wno-unused-cli <cmake -Wno->`.

* The :variable:`CMAKE_WARN_DEPRECATED` and :variable:`CMAKE_ERROR_DEPRECATED`
  variables are deprecated.  The new :command:`cmake_diagnostic` command should
  be used instead.

* The :prop_dir:`MACROS` directory property does not exist anymore.
  See policy :policy:`CMP0217`.

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

* A file may belong to at most one non-``HEADERS`` :ref:`file set <file sets>`
  in a target.  See policy :policy:`CMP0211`.

* :command:`macro` invocations now preserve backslashes in arguments.
  See policy :policy:`CMP0219`.

* :command:`variable_watch` callback command arguments preserve backslashes.
  See policy :policy:`CMP0219`.

* :manual:`ctest(1)` now exits with non-zero if invoked with no
  arguments and no test input file exists.

* Test drivers generated by the :command:`create_test_sourcelist` command now
  support the ``-N`` option to list all tests, one per line.  This is useful in
  combination with the new :command:`discover_tests` command.

* Names of executables given to the ``DEPENDS`` argument of
  :command:`add_custom_command` no longer have ``.exe`` suffixes stripped to
  establish target-level dependencies. See policy :policy:`CMP0212`.

* Targets which provide C++ modules may now be consumed by targets with
  different :prop_tgt:`compile features <COMPILE_FEATURES>` and
  :prop_tgt:`options <COMPILE_OPTIONS>` than the provider.
