Files
CMake/Help/release/4.2.rst
Peter Kokot c8ea0ba3be Find*: Add missing <PackageName>_FOUND variables
* FindKDE4: Added note about KDE4_FOUND result variable (it is set by
  the upstream FindKDE4Internal module, and now also synced in the docs
  and code for consistency).

For the sake of completeness with other find modules, also the following
deprecated find modules are synced as they already provided these
variables:

* FindDart: Documented the Dart_FOUND result variable.
* FindUnixCommands: Updated documentation (documented UnixCommands_FOUND
  result variable, and listed cache variables used by this module).

Issue: #27242
2025-10-13 12:06:58 -04:00

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8.5 KiB
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CMake 4.2 Release Notes
***********************
.. only:: html
.. contents::
Changes made since CMake 4.1 include the following.
New Features
============
File-Based API
--------------
* The :manual:`cmake-file-api(7)` "codemodel" version 2 ``version`` field has
been updated to 2.9.
* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" and
"directory" objects gained a new ``codemodelVersion`` field.
* The :manual:`cmake-file-api(7)` "codemodel" version 2 now includes imported
targets and all interface library targets in its replies. Previously,
imported targets were omitted, and only those interface targets that
participated in the build system were included. The following changes
support these new additions:
* The "target" object gained ``imported``, ``local``, and ``abstract`` fields.
* The "target" object's ``type`` field can now also hold the value
``UNKNOWN_LIBRARY``.
* The "codemodel" object's ``configurations`` entries gained a new
``abstractTargets`` array.
* Entries in the ``directories`` and ``projects`` arrays of the "codemodel"
object's ``configurations`` entries gained a new ``abstractTargetIndexes``
array.
* The :manual:`cmake-file-api(7)` "codemodel" version 2 "target" object gained
new ``linkLibraries``, ``interfaceLinkLibraries``, ``compileDependencies``,
``interfaceCompileDependencies``, ``objectDependencies``, and
``orderDependencies`` fields.
Generators
----------
* The :generator:`Visual Studio 18 2026` generator was added. This is
experimental and based on "Visual Studio 2026 Insiders" because this
version of VS has not been released.
* The :generator:`FASTBuild` generator was added.
Platforms
---------
* CMake now supports :ref:`Cross Compiling for Emscripten` with simple
toolchain files.
Command-Line
------------
* The :manual:`cmake(1)` command-line tool now supports
``cmake -E copy_if_newer`` and ``cmake -E copy_directory_if_newer``
subcommands to copy files based on timestamp comparison instead of
content comparison. These commands copy files only if the source is
newer than the destination, providing better performance for build
systems compared to ``copy_if_different`` which compares file contents.
Commands
--------
* The :command:`cmake_language(TRACE)` command was added to enable or
disable tracing during script execution.
* The :command:`set(CACHE{<variable>}) <set(CACHE)>` and
:command:`unset(CACHE{<variable>}) <unset(CACHE)>` commands were added to
explicitly set and unset cache entries.
* The :command:`string(REGEX QUOTE)` command was added to
generate a regular expression exactly matching a string.
Variables
---------
* The :variable:`CMAKE_CXX_STDLIB_MODULES_JSON` variable was added to set
the path to the ``import std`` metadata file for the standard library
rather than using the compiler to discover its location.
* The :variable:`CMAKE_INTERMEDIATE_DIR_STRATEGY` variable and corresponding
:envvar:`CMAKE_INTERMEDIATE_DIR_STRATEGY` environment variable were added
to change the strategy used to name intermediate directories used for
object files and other associated target metadata.
* The :variable:`CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY` variable and
corresponding :envvar:`CMAKE_AUTOGEN_INTERMEDIATE_DIR_STRATEGY` environment
variable were added to change the strategy used to name intermediate
directories used for :manual:`Qt Autogen <cmake-qt(7)>` files.
* The :variable:`CMAKE_SKIP_LINTING` variable and corresponding
:prop_tgt:`SKIP_LINTING` target property were added to tell the
:ref:`Command-Line Build Tool Generators` to skip linting all
sources in a target.
Properties
----------
* The :prop_sf:`INSTALL_OBJECT_NAME` source file property was added to
control names of installed object files for specific compiled sources.
* The :prop_tgt:`INSTALL_OBJECT_NAME_STRATEGY` target property was added
to control the naming strategy for installed object files.
* The :prop_tgt:`INSTALL_OBJECT_ONLY_USE_DESTINATION` target property was
added to more precisely control the installation path for object files.
* The :prop_sf:`JOB_POOL_COMPILE` source file property was added
to assign individual source compilations to :prop_gbl:`JOB_POOLS`.
* The :prop_sf:`OBJECT_NAME` source file property was added to control
object names of compiled source files.
* The :prop_tgt:`UNITY_BUILD_FILENAME_PREFIX` target property was added
to control names of source files generated by :prop_tgt:`UNITY_BUILD`.
Modules
-------
* Nearly all find modules now provide a ``<PackageName>_VERSION`` result
variable matching the casing of its module name. Existing variants such as
``<PackageName>_VERSION_STRING`` and uppercased ``<PACKAGENAME>_VERSION``
are deprecated. See documentation of each find module for details.
* The :module:`CheckTypeSize` module's :command:`check_type_size` command
gained a new ``RESULT_VARIABLE`` keyword to customize the result variable
name instead of the default ``HAVE_<size-var>``.
* The :module:`ExternalProject` module's :command:`ExternalProject_Add`
and :command:`ExternalProject_Add_Step` commands now provide options to set
environment variables on the configure, build, install, and test steps.
* The :module:`FindPython3`, :module:`FindPython2`, and :module:`FindPython`
modules no longer make ``NumPy`` depend on ``Development.Module``.
See policy :policy:`CMP0201`.
* The :module:`GoogleTest` module's :command:`gtest_discover_tests()`
command now sets the ``DEF_SOURCE_LINE`` test property for each
discovered test if gtest supports the ``--gtest_output=json`` option.
This test property is used by some IDEs to locate the source for each test.
* The :module:`UseSWIG` module's :command:`swig_add_library` command gained a
``DEBUG_POSTFIX`` option to control the :prop_tgt:`DEBUG_POSTFIX` target
property.
Generator Expressions
---------------------
* The :genex:`<LANG>_COMPILER_LINKER_ID <C_COMPILER_LINKER_ID>` and
:genex:`<LANG>_COMPILER_LINKER_FRONTEND_VARIANT <C_COMPILER_LINKER_FRONTEND_VARIANT>`
families of generator expressions were added to access the value of the
associated :variable:`CMAKE_<LANG>_COMPILER_LINKER_ID` and
:variable:`CMAKE_<LANG>_COMPILER_LINKER_FRONTEND_VARIANT` variables.
* The :genex:`TARGET_FILE_BASE_NAME`, :genex:`TARGET_IMPORT_FILE_BASE_NAME`,
:genex:`TARGET_LINKER_FILE_BASE_NAME`,
:genex:`TARGET_LINKER_LIBRARY_FILE_BASE_NAME`,
:genex:`TARGET_LINKER_IMPORT_FILE_BASE_NAME`, and
:genex:`TARGET_PDB_FILE_BASE_NAME`
generator expressions gained a ``POSTFIX`` option to control the inclusion
of the :prop_tgt:`<CONFIG>_POSTFIX` target property as part of the base
names of the corresponding files.
* The :genex:`TARGET_INTERMEDIATE_DIR` generator expression was
added to refer to a target's intermediate files directory in
the build tree.
CPack
-----
* The :variable:`CPACK_PACKAGE_CHECKSUM` variable now supports multiple values.
* The :cpack_gen:`CPack NSIS Generator` gained a
:variable:`CPACK_NSIS_CRC_CHECK` variable for setting the ``CRCCheck``
attribute.
* The :cpack_gen:`CPack WIX Generator` gained a
:variable:`CPACK_WIX_CAB_PER_COMPONENT` variable to enable one ``.cab``
per component.
Deprecated and Removed Features
===============================
* All find modules now provide a ``<PackageName>_FOUND`` result variable
matching the casing of its module name. Existing variants, such as the
uppercased ``<PACKAGENAME>_FOUND``, are deprecated where appropriate.
See documentation of each find module for details.
* The :module:`FindwxWidgets` module's result variable
``wxWidgets_USE_FILE`` is now deprecated in favor of including the
:module:`UsewxWidgets` module directly.
* The :generator:`Visual Studio 14 2015` generator is now deprecated
and will be removed in a future version of CMake.
Other Changes
=============
* The :genex:`$<CONFIG:cfgs>` generator expression no longer matches multiple
configurations. See policy :policy:`CMP0199`.
* Selection of configuration and location of imported targets is now more
consistent. See policy :policy:`CMP0200`.
* The :variable:`CMAKE_PARENT_LIST_FILE` variable is no longer defined when
processing a ``CMakeLists.txt`` file. See policy :policy:`CMP0198`.
* For builds targeting the MSVC ABI, all generators now add the ``_MBCS``
preprocessor definition when compiling sources unless ``_UNICODE`` or
``_SBCS`` is found. See policy :policy:`CMP0204`.
* For builds targeting the MSVC ABI, all generators now add the ``_WINDLL``
preprocessor definition when compiling sources in shared libraries.
See policy :policy:`CMP0203`.