Help/release/4.1.rst

CMake 4.1 Release Notes
***********************

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Changes made since CMake 4.0 include the following.

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

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

* The :manual:`cmake-file-api(7)` :ref:`v1 <file-api v1>` now writes
  partial replies when buildsystem generation fails with an error.
  See the :ref:`v1 Reply Error Index <file-api reply error index>`.

Generators
----------

* :ref:`Makefile Generators` and :ref:`Ninja Generators` gained support
  for adding a linker launcher with ``Fortran``.
  See the :variable:`CMAKE_<LANG>_LINKER_LAUNCHER` variable
  and :prop_tgt:`<LANG>_LINKER_LAUNCHER` target property for details.

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

* The :ref:`cmake --build <Build Tool Mode>` command-line tool, when used
  with the :generator:`Xcode` generator, now detects when a third-party
  tool has wrapped the generated ``.xcodeproj`` in a ``.xcworkspace``,
  and drives the build through the workspace instead.

Configure Log
-------------

* The :manual:`cmake-configure-log(7)` now reports events from
  :command:`find_package` (in ``CONFIG`` mode), :command:`find_path`,
  :command:`find_file`, :command:`find_library`, and :command:`find_program`
  commands when first invoked, when their results transition between
  "not found" and "found", or when enabled explicitly by the
  :option:`--debug-find <cmake --debug-find>` command-line option.
  See :ref:`find configure-log event` and
  :ref:`find_package configure-log event`.  Logging may also be controlled
  by the :variable:`CMAKE_FIND_DEBUG_MODE` and
  :variable:`CMAKE_FIND_DEBUG_MODE_NO_IMPLICIT_CONFIGURE_LOG` variables.

Compilers
---------

* `Diab compilers from Wind River Systems`_, versions 5.9.x+, are now
  supported with :variable:`compiler id <CMAKE_<LANG>_COMPILER_ID>` ``Diab``
  for languages ``ASM``, ``C``, and ``CXX``.

.. _`Diab compilers from Wind River Systems`: https://www.windriver.com/resource/wind-river-diab-compiler-product-overview

* `Renesas Compilers`_ are now supported with
  :variable:`compiler id <CMAKE_<LANG>_COMPILER_ID>` ``Renesas`` for
  languages ``ASM`` and ``C``.

.. _Renesas Compilers: https://www.renesas.com

Commands
--------

* The :command:`add_dependencies` command may be called with no dependencies.

* The :command:`cmake_pkg_config` command now supports the ``IMPORT`` and
  ``POPULATE`` subcommands for interfacing CMake targets with pkg-config based
  dependencies.

* The :command:`project` command now has experimental support for the
  ``COMPAT_VERSION`` keyword, gated by
  ``CMAKE_EXPERIMENTAL_EXPORT_PACKAGE_INFO``.

Variables
---------

* The :variable:`CMAKE_FIND_REQUIRED` variable was added to tell
  :command:`find_package`, :command:`find_path`, :command:`find_file`,
  :command:`find_library`, and :command:`find_program` to be ``REQUIRED``
  by default.  The commands also gained an ``OPTIONAL`` keyword to ignore
  the variable for a specific call.

* The :variable:`CMAKE_<LANG>_COMPILER_ARCHITECTURE_ID` variable is now
  populated for most compilers, and documented for public use.

* The :variable:`CMAKE_<LANG>_ICSTAT` variable and corresponding
  :prop_tgt:`<LANG>_ICSTAT` target property were added to tell
  the :ref:`Makefile Generators` and the :ref:`Ninja Generators`
  to run the IAR ``icstat`` tool along with the compiler for
  ``C`` and ``CXX`` languages.

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

* The :envvar:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES_EXCLUDE` environment
  variable was added to optionally exclude specific libraries from the
  detected set of :variable:`CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES`.

Properties
----------

* The :prop_tgt:`AUTOMOC_INCLUDE_DIRECTORIES` target property and associated
  :variable:`CMAKE_AUTOMOC_INCLUDE_DIRECTORIES` variable were added to
  override the automatic discovery of moc includes from a target's transitive
  include directories.

* The :prop_sf:`MACOSX_PACKAGE_LOCATION` source file property now
  works when set on a source directory, and copies its entire tree
  into the bundle.

* The :prop_tgt:`PDB_NAME` and :prop_tgt:`COMPILE_PDB_NAME` target properties
  now support :manual:`generator expressions <cmake-generator-expressions(7)>`.

Modules
-------

* The :module:`FindASPELL` module now provides a version variable, imported
  targets, and components to optionally select the Aspell library and
  executable separately.

* The :module:`FindBLAS` and :module:`FindLAPACK` modules now support the
  NVIDIA Performance Libraries (NVPL).

* The :module:`FindProtobuf` module's :command:`protobuf_generate(DEPENDENCIES)`
  command argument now accepts multiple values.

* The :module:`FindProtobuf` module's :command:`protobuf_generate_cpp` and
  :command:`protobuf_generate_python` commands, together with their
  ``Protobuf_IMPORT_DIRS`` and ``PROTOBUF_GENERATE_CPP_APPEND_PATH`` hint
  variables, are now deprecated in favor of the :command:`protobuf_generate`
  command.

Regular Expressions
-------------------

* The :command:`string(REGEX MATCHALL)`, :command:`string(REGEX REPLACE)`, and
  :command:`list(TRANSFORM REPLACE)` commands now match the regular expression
  ``^`` anchor at most once in repeated searches, at the start of the input.
  See policy :policy:`CMP0186`.

* The :command:`string(REGEX REPLACE)` command now allows references to
  unmatched groups.  They are replaced with empty strings.

* The :command:`string(REGEX MATCH)`, :command:`string(REGEX MATCHALL)`, and
  :command:`string(REGEX REPLACE)` commands now allow zero-length matches.

CTest
-----

* :manual:`ctest(1)` gained a
  :option:`--schedule-random-seed <ctest --schedule-random-seed>`
  option to specify a numeric random seed to make
  :option:`ctest --schedule-random` deterministic for reproduction.

CPack
-----

* The :cpack_gen:`CPack NuGet Generator` gained option
  :variable:`CPACK_NUGET_SYMBOL_PACKAGE` to generate NuGet
  symbol packages containing PDB files.

* The :cpack_gen:`CPack RPM Generator` gained
  :variable:`CPACK_RPM_PACKAGE_ENHANCES`,
  :variable:`CPACK_RPM_PACKAGE_RECOMMENDS`, and
  :variable:`CPACK_RPM_PACKAGE_SUPPLEMENTS`
  variables to specify the corresponding RPM spec fields.

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

* The :module:`FindGTest` module's result variables ``GTEST_INCLUDE_DIRS``,
  ``GTEST_LIBRARIES``, ``GTEST_MAIN_LIBRARIES``, and ``GTEST_BOTH_LIBRARIES``
  are now deprecated in favor of using ``GTest::gtest`` and
  ``GTest::gtest_main`` imported targets.

* The :module:`FindGCCXML` module has been deprecated via policy
  :policy:`CMP0188`.  Port projects to CastXML instead.

* The :module:`FindCABLE` module has been deprecated via policy
  :policy:`CMP0191`.

* The :module:`CMakeDetermineVSServicePack` module has been deprecated
  via policy :policy:`CMP0196`.  Port projects to the
  :variable:`CMAKE_<LANG>_COMPILER_VERSION` variable instead.

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

* The :module:`ExternalProject` module no longer checks the ``URL`` archive
  file extension.  Any archive type that :option:`cmake -E tar <cmake-E tar>`
  can extract is now allowed.

* Modules :module:`FindPython3`, :module:`FindPython2` and
  :module:`FindPython` now enforce consistency of artifacts in
  cross-compiling mode.  This prevents mixing host and target artifacts.
  See policy :policy:`CMP0190`.

* The :module:`GNUInstallDirs` module now prefers to default
  ``SYSCONFDIR``, ``LOCALSTATEDIR``, and ``RUNSTATEDIR`` to
  absolute paths when installing to special prefixes.
  See policy :policy:`CMP0192`.

* The :module:`GNUInstallDirs` module now caches ``CMAKE_INSTALL_*``
  variables with their leading ``usr/`` for install prefix ``/``.
  See policy :policy:`CMP0193`.

* The :command:`install(TARGETS)` command no longer ignores file sets which
  haven't been defined at the point it is called. The ordering of
  :command:`target_sources(FILE_SET)` and ``install(TARGETS)`` is no longer
  semantically relevant.

* Enabling ``ASM`` no longer accidentally succeeds using ``MSVC``'s ``cl``
  C compiler as an assembler.  See policy :policy:`CMP0194`.

* The MSVC link ``-machine:`` flag is no longer added to the
  ``CMAKE_*_LINKER_FLAGS`` variables.  See policy :policy:`CMP0197`.

* The :ref:`Visual Studio Generators` now suppress Visual Studio's default
  ``-Zc:forScope``, ``-Zc:inline``, and ``-Zc:wchar_t`` compiler flags,
  and ``-dynamicbase``, ``-errorreport``, ``-nxcompat``, and ``-safeseh``
  link flags, if they are not specified by the project or user.  This makes
  builds more consistent with other generators, and with what projects and
  users actually specify.

* The :genex:`TARGET_PROPERTY` generator expression now evaluates the
  :prop_tgt:`LINK_LIBRARIES` and :prop_tgt:`INTERFACE_LINK_LIBRARIES`
  target properties transitively.  See policy :policy:`CMP0189`.

Updates
=======

Changes made since CMake 4.1.0 include the following.

4.1.1
-----

* This version made no changes to documented features or interfaces.
  Some implementation updates were made to support ecosystem changes
  and/or fix regressions.

4.1.2
-----

* The :command:`file(GENERATE)` command, when evaluating generator
  expressions, now uses the value of policy :policy:`CMP0189` as of
  each call site.  Previously, it used the value as of the end of the
  directory's ``CMakeLists.txt``, as all other generator expression
  evaluations do.

4.1.3
-----

* When building for macOS with the :generator:`Xcode` generator,
  :variable:`CMAKE_OSX_DEPLOYMENT_TARGET` once again defaults to the
  host's macOS version if it is older than the macOS SDK version,
  as it did in CMake versions prior to 4.0.

* The :command:`execute_process` command once again terminates child
  processes when its ``TIMEOUT`` is reached.  This was accidentally
  regressed by CMake 3.29.

4.1.4, 4.1.5, 4.1.6
-------------------

* These versions made no changes to documented features or interfaces.
  Some implementation updates were made to support ecosystem changes
  and/or fix regressions.