CMake 3.24.0-rc1 is ready for testing

June 14, 2022

I am proud to announce the first CMake 3.24 release candidate.
https://cmake.org/download/

Documentation is available at:
https://cmake.org/cmake/help/v3.24

Release notes appear below and are also published at
https://cmake.org/cmake/help/v3.24/release/3.24.html

Some of the more significant changes in CMake 3.24 are:

  • The “FetchContent” module and the “find_package()” command now
    support integration capabilities.

  • The “LINK_LIBRARY” generator expression was added to manage how
    libraries are specified during the link step.

  • The Visual Studio Generators now support “SYSTEM” headers when using
    VS 2019 Update 11 or later.

  • “cmake(1)” gained the “–fresh” command-line option to remove any
    existing “CMakeCache.txt” file and associated “CMakeFiles/”
    directory, when configuring a build tree, thus starting a new
    configuration as if the build tree were freshly created.

  • The “CMAKE_COMPILE_WARNING_AS_ERROR” variable and corresponding
    “COMPILE_WARNING_AS_ERROR” target property were added to enable
    compilation with a compiler-specific flag to treat warnings as
    errors, such as “-Werror”.

  • The “find_file()”, “find_path()”, “find_library()”,
    “find_program()”, and “find_package()” commands gained the
    “NO_CMAKE_INSTALL_PREFIX” option to control searching
    “CMAKE_INSTALL_PREFIX”.

  • The “find_file()”, “find_path()”, “find_library()”,
    “find_program()”, and “find_package()” commands gained the ability
    to specify which Windows Registry views must be queried.

CMake 3.24 Release Notes
************************


Changes made since CMake 3.23 include the following.

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

Presets
-------

* "cmake-presets(7)" files now support schema version "5".

* "cmake-presets(7)" files now support a "${pathListSep}" macro, which
expands to ":" or ";" based on the platform.

* "cmake-presets(7)" files gained support for specifying a
"testOutputTruncation" field in test presets, which specifies the
truncation mode once the maximum test output size has been reached.

Generators
----------

* The "Green Hills MULTI" generator now generates build rules to re-
run CMake if any CMake files are updated.

* The Visual Studio Generators now support "SYSTEM" headers when using
VS 2019 Update 11 or later.

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

* "cmake(1)" gained the "--fresh" command-line option to remove any
existing "CMakeCache.txt" file and associated "CMakeFiles/"
directory, when configuring a build tree, thus starting a new
configuration as if the build tree were freshly created.

* "cmake(1)" gained the "--compile-no-warning-as-error" command-line
option which causes the effects of the "COMPILE_WARNING_AS_ERROR"
target property and "CMAKE_COMPILE_WARNING_AS_ERROR" variable to be
ignored.

* The "cmake(1)" "--trace=json-v1" trace format gained fields
"global_frame" and "line_end".

* The "cmake(1)" "-E" commands "cat" and "env" learned to respect a
double dash ("--") argument that acts as a delimiter indicating the
end of options. Any following arguments are treated as
operands/positional arguments, even if they begin with a dash "-"
character.

* The "cmake(1)" "-E tar" command gained the "--touch" option to keep
the current local timestamp instead of extracting file timestamps
from the archive.

Compilers
---------

* LLVM's flang Fortran compiler is now supported on some platforms,
with compiler id "LLVMFlang".

* ADSP compiler support (SHARC and Blackfin) now covers both CCES and
VDSP++ installations, with required configuration now done in the
compiler module itself rather than the "Generic-ADSP" platform
module.

Platforms
---------

* A dedicated "ADSP" platform has been added to replace the existing
"Generic-ADSP" implementation. This features automatic detection of
the latest CCES/VDSP++ install and compiler selection ("cc21k" vs.
"ccblkfn") based off of the "CMAKE_SYSTEM_PROCESSOR" variable.

Commands
--------

* The "cmake_host_system_information()" command, on Windows, gained a
"QUERY WINDOWS_REGISTRY" mode. See its Query Windows registry
section.

* The "cmake_language()" command gained a new
"SET_DEPENDENCY_PROVIDER" sub-command.  When a dependency provider
is set, calls to "find_package()" and "FetchContent_MakeAvailable()"
can be redirected through a custom command, which can choose to
fulfill the request directly, modify how the request is processed,
or leave it to be fulfilled by the built-in implementation.  See
Dependency Providers.

* The "file(DOWNLOAD)" command gained options "RANGE_START" and
"RANGE_END" to specify a range of bytes to download.  This can be
useful for downloading parts of big binary files.

* The "find_file()", "find_path()", "find_library()",
"find_program()", and "find_package()" commands gained the
"NO_CMAKE_INSTALL_PREFIX" option to control searching
"CMAKE_INSTALL_PREFIX".

* The "find_file()", "find_path()", "find_library()",
"find_program()", and "find_package()" commands gained the ability
to specify which Windows Registry views must be queried.

* The "find_package()" command gained a "GLOBAL" option that allows
for the promotion of imported targets to global scope for the
duration of the "find_package()" call.

* The "if()" command gained the capability to compare paths by using
the "PATH_EQUAL" operator.  See policy "CMP0139".

Variables
---------

* The "CMAKE_COLOR_DIAGNOSTICS" variable was added to control color
diagnostics generated by compilers.  This variable also controls
color build system messages with Makefile Generators, replacing
"CMAKE_COLOR_MAKEFILE".

The "CMAKE_COLOR_DIAGNOSTICS" environment variable was added to set
a default value for "CMAKE_COLOR_DIAGNOSTICS".

* The "CMAKE_COMPILE_WARNING_AS_ERROR" variable and corresponding
"COMPILE_WARNING_AS_ERROR" target property were added to enable
compilation with a compiler-specific flag to treat warnings as
errors, such as "-Werror".

* The "CMAKE_CUDA_ARCHITECTURES" variable and associated
"CUDA_ARCHITECTURES" target property now support the special
"native" value to compile for the architectures(s) of the host's
GPU(s).

* The "CMAKE_FIND_PACKAGE_TARGETS_GLOBAL" variable was added to toggle
behavior of the "find_package()" command's new "GLOBAL" option.

* The "CMAKE_FIND_USE_INSTALL_PREFIX" variable was added to toggle
behavior of the "find_file()", "find_library()", "find_path()",
"find_package()", and "find_program()" commands' new
"NO_CMAKE_INSTALL_PREFIX" option.

* The "CMAKE_PROJECT_TOP_LEVEL_INCLUDES" variable was added to allow
injecting custom code at the site of the first "project()" call,
after the host and target platform details have been determined.

* The "CMAKE_TRY_COMPILE_NO_PLATFORM_VARIABLES" variable was added to
tell the "try_compile()" command not to pass any platform variables
to the test project.

* The "CMAKE_VERIFY_INTERFACE_HEADER_SETS" variable and corresponding
"VERIFY_INTERFACE_HEADER_SETS" target property were added to enable
build rules that verify all headers in header sets can be used on
their own.

* The "CMAKE_WATCOM_RUNTIME_LIBRARY" variable and
"WATCOM_RUNTIME_LIBRARY" target property were introduced to select
the runtime library used by compilers targeting the Watcom ABI. See
policy "CMP0136".

* The "CMAKE_XCODE_XCCONFIG" variable and corresponding
"XCODE_XCCONFIG" target property were added to tell the "Xcode"
generator to handle "xcconfig" files.

Properties
----------

* The "INTERFACE_LINK_LIBRARIES_DIRECT" and
"INTERFACE_LINK_LIBRARIES_DIRECT_EXCLUDE" target properties were
added to express usage requirements affecting a consumer's direct
link dependencies.

* The "INTERFACE_HEADER_SETS_TO_VERIFY" target property was added to
specify which header sets should be verified by
"VERIFY_INTERFACE_HEADER_SETS".

* The "LINK_LIBRARIES" target property now supports the
"$              " generator expression. See policy "CMP0131".


* The "VS_DOTNET_STARTUP_OBJECT" target property was added to tell
Visual Studio Generators which startup class shall be used when the
program or project is executed. This is necessary when more than one
"static void Main(string[])" function signature is available in a
managed .NET project.

* The "VS_NO_COMPILE_BATCHING" target property was added to tell
Visual Studio Generators whether to disable compiler parallelism and
call the compiler with one source file at a time.

Modules
-------

* The "ExternalProject" module "ExternalProject_Add()" command gained
a new "DOWNLOAD_EXTRACT_TIMESTAMP" option for controlling whether
the timestamps of extracted contents are set to match those in the
archive when the "URL" download method is used. Policy "CMP0135" was
added to enable the option by default.

* The "FetchContent" module and the "find_package()" command now
support integration capabilities:

* "FetchContent_MakeAvailable()" can now try to satisfy a dependency
by calling "find_package()" first.  A new
"FETCHCONTENT_TRY_FIND_PACKAGE_MODE" variable controls whether
this is done by default for all dependencies, is opt-in per
dependency, or is disabled entirely.

* "find_package()" can be re-routed to call
"FetchContent_MakeAvailable()" instead.  A new read-only
"CMAKE_FIND_PACKAGE_REDIRECTS_DIR" variable points to a directory
where config package files can be located to facilitate these re-
routed calls.

* The "FindJNI" module now provides imported targets.

* The "FindMatlab" module "matlab_add_mex()" function gained a
"NO_IMPLICIT_LINK_TO_MATLAB_LIBRARIES" option to disable automatic
linking of MATLAB libraries.

* The "FindPkgConfig" module learned to find static libraries in
addition to the default search for shared libraries.
"pkg_check_modules()" gained a "STATIC_TARGET" option to make the
imported target reference static libraries.

* The "FindZLIB" gained a new "ZLIB_USE_STATIC_LIBS" variable to
search only for static libraries.

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

* The "LINK_LIBRARY" generator expression was added to manage how
libraries are specified during the link step. The
"CMAKE__LINK_LIBRARY_USING_" and
"CMAKE_LINK_LIBRARY_USING_" variables are used to define
features usable by the "LINK_LIBRARY" generator expression.
Moreover, the "LINK_LIBRARY_OVERRIDE" and
"LINK_LIBRARY_OVERRIDE_                 " target properties are available to
resolve incompatible features.

The "LINK_LIBRARY" generator expression can link frameworks in
various ways when targeting "Apple" platforms. The following
features were added:

* "FRAMEWORK"

* "NEEDED_FRAMEWORK"

* "REEXPORT_FRAMEWORK"

* "WEAK_FRAMEWORK"

The "LINK_LIBRARY" generator expression can link libraries in
various ways when targeting "Apple" platforms. The following
features were added:

* "NEEDED_LIBRARY"

* "REEXPORT_LIBRARY"

* "WEAK_LIBRARY"

The "LINK_LIBRARY" generator expression gained the feature
"WHOLE_ARCHIVE" to force load of all members in a static library.
This feature is supported on the following target platforms:

* all "Apple" variants

* "Linux"

* all "BSD" variants

* "SunOS"

* "Windows"

* "CYGWIN"

* "MSYS"

* The "LINK_GROUP" generator expression was added to manage the
grouping of libraries during the link step.  The
"CMAKE__LINK_GROUP_USING_" and
"CMAKE_LINK_GROUP_USING_" variables are used to define
features usable with the "LINK_GROUP" generator expression. This
release defines the "RESCAN" feature, which can be used to handle
circular references among static libraries when using toolchains for
Linux, BSD, SunOS and GNU toolchains for Windows.

* The "PATH" generator expression was added to manage paths.

* The "PATH_EQUAL" generator expression was added to manage path
comparisons.

* The "TARGET_BUNDLE_DIR_NAME" generator expression was added to
evaluate to the name of the bundle directory for a given bundle
target.

CTest
-----

* "ctest(1)" gained a "--test-output-truncation" option (and
corresponding "CTEST_CUSTOM_TEST_OUTPUT_TRUNCATION" variable) to
specify the truncation mode once the maximum test output size has
been reached. Possible values are "tail" (default), "middle" or
"head".

CPack
-----

* The "CPack WIX Generator" gained a new variable,
"CPACK_WIX_ARCHITECTURE", to specify the installer architecture in
order to support computers running Windows for ARM.

* CPack now supports the "CPACK_THREADS" option for "zstd" compression
when compiled with libarchive 3.6 or higher.  It is supported by
official CMake binaries available on cmake.org.

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

* The "CPack" module no longer enables the SLA by default in the
"CPack DragNDrop Generator".  See policy "CMP0133" and the
"CPACK_DMG_SLA_USE_RESOURCE_FILE_LICENSE" variable.

* The deprecated "CPack PackageMaker Generator" has been removed.

* The "FindGLUT" module no longer provides the undocumented
"GLUT_LIBRARY" and "GLUT_INCLUDE_PATH" result variables.

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

* CMake no longer sets environment variables like "CC", "CXX", etc.
when enabling the corresponding language during the first CMake run
in a build directory.  See policy "CMP0132".

* The "CheckIPOSupported" module "check_ipo_supported()" command now
uses the caller's "CMAKE__FLAGS" and
"CMAKE__FLAGS_" values. See policy "CMP0138".

* The "MSYS Makefiles" and "MinGW Makefiles" generators, when a
compiler is not explicitly specified, now select the first compiler
(of any name) found in directories listed by the "PATH" environment
variable.

* The "try_compile()" command whole-project signature now propagates
platform variables.  See policy "CMP0137".

* The "while()" command now diagnoses errors during condition
evaluation.  See policy "CMP0130".

* The precompiled macOS binaries provided on cmake.org no longer
attach a SLA to the ".dmg" packages.  This was removed because macOS
12 deprecated the tools used to attach ".dmg" resources.

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