New Features

Languages

The ASM_MARMASM language was added to support the Microsoft ARM assembler language.

The :option:cmake -E copy <cmake-E copy> command-line tool now supports a -t argument.
The :option:cmake -E copy_directory_if_different <cmake-E copy_directory_if_different> command-line tool was added.

CMake now writes a YAML log of configure-time checks to CMakeFiles/CMakeConfigureLog.yaml under the top of the build tree. See the :manual:cmake-configure-log(7) manual.

The :manual:cmake-file-api(7) "codemodel" version 2 version field has been updated to 2.5.
The :manual:cmake-file-api(7) "codemodel" version 2 "target" object gained a new fileSets field and associated fileSetIndex field to sources objects.
The :manual:cmake-file-api(7) "codemodel" version 2 "directory" object installers field gained a new cxxModuleBmi installer type and an associated cxxModuleBmiTarget field.
The :manual:cmake-file-api(7) gained a new "configureLog" object kind that enables stable access to the :manual:cmake-configure-log(7).

The :command:add_custom_command and :command:add_custom_target commands now support :manual:generator expressions <cmake-generator-expressions(7)> in their COMMENT option.
The :command:message command gained a CONFIGURE_LOG mode to record an entry in the :manual:cmake-configure-log(7).
The :command:string(TIMESTAMP) and :command:file(TIMESTAMP) commands now support the %z and %Z specifiers for the time zone.
The :command:try_compile and :command:try_run commands gained a LOG_DESCRIPTION option specifying text to be recorded in the :manual:cmake-configure-log(7).
The :command:try_compile and :command:try_run commands gained a NO_LOG option to skip recording a :manual:cmake-configure-log(7) entry.

The :variable:CMAKE_<LANG>_COMPILER_FRONTEND_VARIANT variable is now set for GNU, MSVC, and AppleClang compilers that have only one frontend variant.
A :variable:CMAKE_VS_VERSION_BUILD_NUMBER variable is now set by :ref:Visual Studio Generators for VS 2017 and above to report the four-component Visual Studio version number.

The :prop_tgt:<LANG>_CLANG_TIDY_EXPORT_FIXES_DIR target property was added to allow the clang-tidy tool to export its suggested fixes to a set of .yaml files. A new :variable:CMAKE_<LANG>_CLANG_TIDY_EXPORT_FIXES_DIR variable was created to initialize this property.
The :prop_tgt:XCODE_EMBED_EXTENSIONKIT_EXTENSIONS <XCODE_EMBED_<type>> target property was added to tell the :generator:Xcode generator to embed ExtensionKit-based extensions such as extensions using the Background Assets framework. Aspects of the embedding can be customized with:
- :prop_tgt:XCODE_EMBED_EXTENSIONKIT_EXTENSIONS_PATH <XCODE_EMBED_<type>>
- :prop_tgt:XCODE_EMBED_EXTENSIONKIT_EXTENSIONS_CODE_SIGN_ON_COPY <XCODE_EMBED_<type>_CODE_SIGN_ON_COPY>
- :prop_tgt:XCODE_EMBED_EXTENSIONKIT_EXTENSIONS_REMOVE_HEADERS_ON_COPY <XCODE_EMBED_<type>_REMOVE_HEADERS_ON_COPY>

The :module:ExternalProject module's :command:ExternalProject_Add command gained an INSTALL_BYPRODUCTS option to specify files generated by the install step.
The :module:FindCUDAToolkit module:
- gained support for the sbsa-linux cross compilation target, and
- now provides an imported target for nvrtc_static, if found.
The :module:FindImageMagick module now provides imported targets.
The :module:FindPython3 and :module:FindPython modules gained support for the Stable Application Binary Interface_.
The :module:UseSWIG module gained support for the perl5 language.

The :genex:$<BUILD_LOCAL_INTERFACE:...> generator expression was added to prevent usage requirements from being exported to dependent projects.

The :envvar:CTEST_NO_TESTS_ACTION environment variable was added to provide a default value for the :option:--no-tests=\<action\> <ctest --no-tests> command line argument of :manual:ctest(1).

The CMakeFiles/CMakeOutput.log and CMakeFiles/CMakeError.log files are no longer populated by CMake's built-in modules. :manual:cmake(1) no longer suggests looking at them after a CMake Error occurs. Information previously logged to those files is instead logged to the :manual:cmake-configure-log(7).
On CYGWIN, the undocumented CMAKE_LEGACY_CYGWIN_WIN32 mode for compatibility with CMake versions older than 2.8.4 has been removed.

:ref:Language Standard Flags, such as -std=c++11, when generated due to :command:target_compile_features or :variable:CMAKE_<LANG>_STANDARD, are now placed before flags added by :command:target_compile_options, rather than after them.
For all COMPILE_DEFINITIONS properties, any leading -D on an item is removed whether or not it was specified by a generator expression.
The compile_commands.json database enabled by :variable:CMAKE_EXPORT_COMPILE_COMMANDS now provides the output field in the compile commands objects. This allows multi-config generators, such as the :generator:Ninja Multi-Config generator, to provide the compile commands for all configurations.
The :prop_gbl:USE_FOLDERS global property is treated as ON by default. See policy :policy:CMP0143.
The top-level :command:project call will now emit an author warning if the documented command order in relation to :command:cmake_minimum_required is not respected.
The :option:cmake --trace option now follows :command:try_compile and :command:try_run invocations.

Changes made since CMake 3.26.0 include the following.

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

The :manual:cmake-file-api(7) "codemodel" version 2 "target" object fileSets field was introduced by CMake 3.26.0 with entries of its baseDirectories member incorrectly expressed as absolute paths even if they are inside the top-level source directory. This has been fixed. Clients must be updated to expect relative paths under the top-level source directory.