CMake 4.4.0-rc2 is ready for testing

Announcements
1

I am proud to announce the second CMake 4.4 release candidate.
https://cmake.org/download/

Documentation is available at:
https://cmake.org/cmake/help/v4.4

Release notes appear below and are also published at
https://cmake.org/cmake/help/v4.4/release/4.4.html

Release milestone is available at:
release milestone

Some of the most significant changes in CMake 4.4 are:

  • CMake diagnostic actions are now tracked in a new state type managed
    by the “cmake_diagnostic()” command. The new system introduces several
    new diagnostic categories.

  • “macro()” invocations now preserve backslashes in arguments. See
    policy “CMP0219”.

  • “cmake(1)”, “ctest(1)”, and “cpack(1)” gained “–presets-file”
    arguments to support loading “presets” from the specified file.

  • The Ninja Generators now support generating a build target named
    “test_prep/<test-name>” for each test added by “add_test()”, which
    builds all dependencies for that test. This behavior is enabled by
    the new “CMAKE_TEST_BUILD_DEPENDS” variable.

  • “cmake --install” now supports installing multiple components.

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

  • The “execute_process()” command gained “ENVIRONMENT” and
    “ENVIRONMENT_MODIFICATION” options to run child processes with a
    modified environment.

  • A “SOURCES” file set type was added to specify a target’s source
    files via file sets.

  • The “SCOPE”, “TYPE”, “BASE_DIRS”, “SOURCES”, and “INTERFACE_SOURCES”
    file set properties were added to provide the declared details of a
    file set.

  • The “CMakePackageConfigHelpers” module’s
    “write_basic_package_version_file()” command now supports
    “SamePatchVersion”, “SameFullVersion”, and “SemanticVersion”
    compatibility modes.

  • “ctest(1)” gained support for forwarding extra arguments to test
    executables using a “–” separator.

CMake 4.4 Release Notes

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 “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 “cmake-diagnostics(7)” manual for
    a list of available categories.

  • The “CMD_INSTALL_ABSOLUTE_DESTINATION” diagnostic category was added
    to diagnose “install()” commands that specify an absolute
    “DESTINATION”. This diagnostic may be controlled with the
    “-Winstall-absolute-destination” command-line option, the
    “installAbsoluteDestination” field in a “CMake Presets” “warnings”
    object, or the “cmake_diagnostic()” command.

Presets

  • “cmake-presets(7)” files now support schema version 12.

  • “cmake(1)”, “ctest(1)”, and “cpack(1)” gained “–presets-file”
    arguments to support loading “presets” from the specified file
    instead of “CMakePresets.json” and/or “CMakeUserPresets.json”. See
    “cmake --presets-file”, “cmake --build --presets-file”, “cmake
    –workflow --presets-file”, “ctest --presets-file”, and “cpack
    –presets-file” for details.

  • “cmake-presets(7)”, in schema version 12 and above, now expand the
    ${fileDir} macro to the directory of the presets file containing the
    “${fileDir}” macro, regardless of whether it is inherited by another
    preset in a different directory.

  • “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 “cmake-file-api(7)” “codemodel” version 2 object has been
    updated to 2.11.

  • The “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 “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 “cmake-file-api(7)” “codemodel” version 2 “installers” object’s
    optional “fileSetType” field gained a new “SOURCES” value to
    incorporate the new “SOURCES” file set type in codemodel replies.

Instrumentation

  • The “cmake-instrumentation(7)” data version has been updated to 1.1.

  • “cmake-instrumentation(7)” gained a “captureOutput” option which
    collects the “stdout” and “stderr” of instrumented commands.

  • “cmake-instrumentation(7)” gained a “compileTrace” option which
    records compiler-generated trace files (e.g., from Clang’s “-ftime-
    trace” flag).

Generators

  • The Ninja Generators now support generating a build target named
    “test_prep/<test-name>” for each test added by “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 “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 “cmake-
    cxxmodules(7)”.

  • The “ibm-flang” compiler is now supported with “compiler id”
    “IBMFlang”.

  • The Pelles C toolchain is now supported with “compiler id”
    “PellesC”.

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

  • The Open Watcom “wlink” linker is now identified with
    “CMAKE_<LANG>_COMPILER_LINKER_ID” “OpenWatcom”.

  • The wild linker is now supported with
    “CMAKE_<LANG>_COMPILER_LINKER_ID” “WILD”.

Command-Line

  • “cmake(1)” now supports “–build <dir> --preset <pre>” regardless of
    the current working directory.

  • The “cmake -D” command-line option now populates a default
    “HELPSTRING” for variables known to CMake.

  • “cmake --install” now supports installing multiple components.

  • “cmake --install” now accepts “-j<N>” in addition to “-j <N>” for
    specifying the number of parallel jobs.

  • The “cmake -E” commands “copy_if_different”, “copy_if_newer”,
    “copy_directory”, “copy_directory_if_different”, and
    “copy_directory_if_newer” gained support for the “-t” argument.

  • The “cmake -E tar” command-line tool gained the “–cmake-tar-
    encoding” flag to specify the pathname encoding used in archives.

Commands

  • The “block()” command can now create a “DIAGNOSTICS” scope.

  • The “cmake_diagnostic()” command was added to manipulate CMake’s
    diagnostic state.

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

  • The “execute_process()” command gained “ENVIRONMENT” and
    “ENVIRONMENT_MODIFICATION” options to run child processes with a
    modified environment.

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

  • The “file(READ_SYMLINK)” command gained a “RESULT” option to capture
    errors without failing.

  • The “if()” command gained a new “DIAGNOSTIC” operator that evaluates
    to true if a given diagnostic category name is known to CMake.

  • The “include()” command now has a “NO_DIAGNOSTIC_SCOPE” option.

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

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

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

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

  • The “string(JSON … PARTIAL_EQUAL)” command was added to compare
    two JSON values using partial equality.

File Sets

  • A “SOURCES” file set type was added to specify a target’s source
    files via file sets.

  • The “CXX_SCAN_FOR_MODULES” file set property was added to control
    whether a file set’s sources are scanned for C++ modules.

  • The “INDEPENDENT_FILES” file set property was added to specify that
    a file set’s sources do not depend on any generated files.

  • The “JOB_POOL_COMPILE” file set property was added to assign a file
    set’s sources to a specific Ninja job pool.

  • The “SCOPE”, “TYPE”, “BASE_DIRS”, “SOURCES”, and “INTERFACE_SOURCES”
    file set properties were added to provide the declared details of a
    file set.

  • The “SKIP_LINTING” file set property was added to exclude a file
    set’s sources from target-wide code checks.

  • The “SKIP_PRECOMPILE_HEADERS” file set property was added to avoid
    using precompiled headers for a file set’s sources.

  • The “SKIP_UNITY_BUILD_INCLUSION” file set property was added to
    exclude a file set’s sources from inclusion in unity builds.

Variables

  • The “CMAKE_INSTALL_DEFAULT_COMPONENT_NAME” variable gained support
    for a special “<PROJECT_NAME>” placeholder value. It tells each
    “install()” invocation to take a default component name from the
    current “PROJECT_NAME” variable value.

Environment Variables

  • The “CMAKE_DISABLE_PRECOMPILE_HEADERS” environment variable was
    added to disable precompiled headers by default.

Properties

  • The “VERIFY_INTERFACE_HEADER_SETS” and “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 “VERIFY_INTERFACE_HEADER_SETS” and “VERIFY_PRIVATE_HEADER_SETS”
    target properties now support “OBJC” and “OBJCXX” languages in
    addition to “C” and “CXX”.

  • The “VS_SOLUTION_DEPLOY” target property is now implemented for
    targets created by “add_custom_target()”.

Modules

  • The “CMakePackageConfigHelpers” module’s
    “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 “ExternalData” module gained an “ExternalData_LINK_MODE”
    variable to select an ordered list of file materialization modes for
    hard links, symbolic links, and copies.

  • The “ExternalData” module gained an “ExternalData_STATE_ROOT”
    variable to store hash records outside “ExternalData_BINARY_ROOT”.

  • The “ExternalProject” and “FetchContent” modules gained
    “CMAKE_EP_GIT_CLONE_RETRY_COUNT” and
    “CMAKE_EP_GIT_CLONE_RETRY_DELAY” variables to control “git clone”
    retries.

  • The “FindCUDAToolkit” module now creates a “CUDA::sanitizer” target
    for the compute-sanitizer library.

  • The “FindCUDAToolkit” module now provides an imported target for
    “cufilt” in CUDA 11.4 and above.

  • “FindPython” and “FindPython3” modules gained the support of the
    Stable ABI for Free Threaded Python (“SABIT”) as specified by PEP
    803    .

Generator Expressions

  • The “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 Ninja Generators gained the “Swift_SEPARATE_MODULE_EMISSION”
    target property, initialized by the
    “CMAKE_Swift_SEPARATE_MODULE_EMISSION” variable, to control whether
    importable Swift targets emit “.swiftmodule” from a dedicated build
    edge. Policy “CMP0215” enables this by default.

  • The default “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
    “CMP0216”.

  • The “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

  • “ctest(1)” gained support for forwarding extra arguments to test
    executables using a “–” separator.

  • “ctest(1)” gained a CoverageTool option in Dashboard Client mode to
    configure tests for coverage collection by “llvm-cov”.

  • The “ctest_configure()”, “ctest_build()”, “ctest_test()”, and
    “ctest_memcheck()” commands gained “PRESET” and “PRESETS_FILE”
    arguments to support using “presets” for their Dashboard Client
    steps.

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

  • “ctest(1)” gained a “–source-dir” option to specify the source
    directory. When combined with “-T” Configure, this allows CTest to
    perform an initial configure step for an empty binary directory.

  • “ctest(1)” gained support for a “CTEST_SUBMIT_PARTS” variable that
    restricts which parts are uploaded when operating in Dashboard
    Client mode.

  • The “ctest_update()” command gained “VERSION_ONLY” and
    “VERSION_OVERRIDE” options to select or report a source revision
    without requiring the corresponding “CTEST_UPDATE_VERSION_ONLY” or
    “CTEST_UPDATE_VERSION_OVERRIDE” dashboard script variables.

CPack

  • The “CPack Archive Generator” gained the “CPACK_ARCHIVE_ENCODING”
    variable to specify the pathname encoding used in package archives.

  • The “CPack NSIS Generator” gained a new variable
    “CPACK_NSIS_IGNORE_COMPONENTS_PAGE” to ignore the component
    selection page in the installer.

  • The “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 “-W[no-][error=]author”.

  • The “–warn-uninitialized” command-line option is deprecated. The
    new spelling is “-Wuninitialized”.

  • The “–no-warn-unused-cli” command-line option is deprecated. The
    new spelling is “-Wno-unused-cli”.

  • The “CMAKE_WARN_DEPRECATED” and “CMAKE_ERROR_DEPRECATED” variables
    are deprecated. The new “cmake_diagnostic()” command should be used
    instead.

  • The “MACROS” directory property does not exist anymore. See policy
    “CMP0217”.

Other Changes

  • A file may belong to at most one non-“HEADERS” file set in a target.
    See policy “CMP0211”.

  • “macro()” invocations now preserve backslashes in arguments. See
    policy “CMP0219”.

  • “variable_watch()” callback command arguments preserve backslashes.
    See policy “CMP0219”.

  • “ctest(1)” now exits with non-zero if invoked with no arguments and
    no test input file exists.

  • Test drivers generated by the “create_test_sourcelist()” command now
    support the “-N” option to list all tests, one per line. This is
    useful in combination with the new “discover_tests()” command.

  • Names of executables given to the “DEPENDS” argument of
    “add_custom_command()” no longer have “.exe” suffixes stripped to
    establish target-level dependencies. See policy “CMP0212”.

  • Targets which provide C++ modules may now be consumed by targets
    with different “compile features” and “options” than the provider.

Changes made since CMake 4.4.0-rc1:

Ben Boeckel (1):

  • Clang-FindBinUtils: find unprefixed clang-scan-deps binaries as well

Brad King (3):

  • Help: Add release note for the instrumentation version format change in 4.3.4
  • ExternalProject: Fix ENVIRONMENT_MODIFICATION with spaces in values
  • CMake 4.4.0-rc2

Daksh Mamodiya (1):

  • file(ARCHIVE_EXTRACT): Fix resource leaks on error paths

Jakob Ronestjärna (1):

  • ExternalData: Remove redundant debug message

James Miro (1):

  • FindDoxygen: Avoid leaking child process stderr

John Parent (1):

  • Help: Restore sphinx pre-5.0 compatibility

Matthew Woehlke (3):

  • Exports: Capture context for diagnostics
  • CPS: Fix crash when package requires isn’t an object
  • if: Add DIAGNOSTIC <category> condition

Ottmar Zittlau (1):

  • GoogleTest: Avoid cluttering custom working directory during discovery

Tyler Yankee (2):

  • Tests/instrumentation: Check errors for query schema validation
  • instrumentation: Add JSON schema for snippet files

Zack Galbreath (2):

  • ctest: Honor preset binaryDir for initial configuration
  • ctest: Pass CTEST_SITE/CTEST_BUILD_NAME to configure step
2

@brad.king Did the improved diagnostics for cmake presets make it into this release?

3

CMake MR 11987 is in 4.4, yes.

4

I keep wondering when I’ll rate an appearing in the changelog :) (not a big deal, just easier to see when my contributions are shipping)

5

Changes that don’t affect user-facing documented interfaces often don’t get change logs.

FYI, the release notes are added incrementally in the MRs that make the corresponding changes and then consolidated once later. If a MR doesn’t have a release note we’ll ask for one during review if appropriate. If not, then it’s unlikely one will be added later.

All merge requests are assigned a milestone indicating the version that will include them.

6

Improved diagnostics aren’t considered user-facing?

I just think it’s important to let people know that one of the pain points around presets has been alleviated. Whether my name is attached isn’t important, TBH.