I am proud to announce the second CMake 4.0 release candidate.
https://cmake.org/download/
Documentation is available at:
https://cmake.org/cmake/help/v4.0
Release notes appear below and are also published at
https://cmake.org/cmake/help/v4.0/release/4.0.html
Release milestone is available at:
release milestone
Some of the most significant changes in CMake 4.0 are:
-
Compatibility with versions of CMake older than 3.5 has been
removed. Calls to “cmake_minimum_required()” or “cmake_policy()”
that set the policy version to an older value now issue an error.
Note that calls to those commands can still support older versions
of CMake by using their “VERSION” arguments’ “<min>…<max>” syntax.
This requires only the “<min>” version of CMake, but when running a
newer version, sets policies up to the “<max>” version. -
The “CMAKE_POLICY_VERSION_MINIMUM” variable was added to help
packagers and end users try to configure existing projects that have
not been updated to work with supported CMake versions. The
“CMAKE_POLICY_VERSION_MINIMUM” environment variable was added to
initialize it. -
The “$<PATH>” generator expression gained the “NATIVE_PATH”
operation to convert a CMake path into a native one. -
On macOS with Ninja Generators and Makefile Generators, when a
compiler is found in “/usr/bin”, it is now used as-is and is no
longer mapped to the corresponding compiler inside Xcode. -
Builds targeting macOS no longer choose any SDK or pass an
“-isysroot” flag to the compiler by default. Instead, compilers are
expected to choose a default macOS SDK on their own. In order to
use a compiler that does not do this, users must now specify
“-DCMAKE_OSX_SYSROOT=macosx” when configuring their build. -
Precompiled SunOS “sparc” and “i386” binaries are now provided on
cmake.org.
CMake 4.0 Release Notes
Changes made since CMake 3.31 include the following.
New Features
File-Based API
-
The “cmake-file-api(7)” “codemodel” version 2 “version” field has
been updated to 2.8. -
The “cmake-file-api(7)” “codemodel” version 2 “target” object gained
a new “debugger” field.
Command-Line
-
The “cmake --link-no-warning-as-error” option was added to suppress
the effects of the “LINK_WARNING_AS_ERROR” target property and
“CMAKE_LINK_WARNING_AS_ERROR” variable. -
The “cmake --project-file” option was added to specify an alternate
filename for “CMakeLists.txt” files. This is intended for temporary
use by developers during an incremental transition and not for
publication of a final product. CMake will always emit a warning
when the project file is anything other than “CMakeLists.txt”.
Commands
- The “target_link_libraries()” command now supports the “LINKER:”
prefix.
Variables
-
The “AIX” and “CMAKE_HOST_AIX” variables are now set to true when
the target or host system is AIX, respectively. -
Linker flag variables learned to support the “LINKER:” prefix:
-
“CMAKE_EXE_LINKER_FLAGS”
-
“CMAKE_EXE_LINKER_FLAGS_<CONFIG>”
-
“CMAKE_SHARED_LINKER_FLAGS”
-
“CMAKE_SHARED_LINKER_FLAGS_<CONFIG>”
-
“CMAKE_MODULE_LINKER_FLAGS”
-
“CMAKE_MODULE_LINKER_FLAGS_<CONFIG>”
See policy “CMP0181”.
-
-
The “CMAKE_EXECUTE_PROCESS_COMMAND_ERROR_IS_FATAL” variable was
added to specify the “execute_process()” command’s default
“COMMAND_ERROR_IS_FATAL” behavior. -
The “CMAKE_<LANG>LINK_MODE" and "CMAKE<LANG>_DEVICE_LINK_MODE”
variables were added to provide information on how the link step is
done. -
The “CMAKE_LINK_WARNING_AS_ERROR” variable and corresponding
“LINK_WARNING_AS_ERROR” target property were added to link using a
linker-specific flag to treat warnings as errors. -
The “CMAKE_MSVC_RUNTIME_CHECKS” variable and “MSVC_RUNTIME_CHECKS”
target property were introduced to select runtime checks for
compilers targeting the MSVC ABI. See policy “CMP0184”. -
The “CMAKE_POLICY_VERSION_MINIMUM” variable was added to help
packagers and end users try to configure existing projects that have
not been updated to work with supported CMake versions. The
“CMAKE_POLICY_VERSION_MINIMUM” environment variable was added to
initialize it. -
The “CMAKE_XCODE_SCHEME_LLDB_INIT_FILE” variable and corresponding
“XCODE_SCHEME_LLDB_INIT_FILE” target property were added to tell the
“Xcode” generator what to put in the scheme’s “LLDB Init File”
setting. -
The “CMAKE_XCODE_SCHEME_TEST_CONFIGURATION” variable and
corresponding “XCODE_SCHEME_TEST_CONFIGURATION” target property were
added to tell the “Xcode” generator what to put in the scheme’s
“Build Configuration” setting for the test action.
Properties
-
The “DEBUGGER_WORKING_DIRECTORY” target property and corresponding
“CMAKE_DEBUGGER_WORKING_DIRECTORY” variable were added to tell
generators what debugger working directory should be set for
targets. -
The “STATIC_LIBRARY_OPTIONS” target property now supports an
“ARCHIVER:” prefix to pass options to the archiver through the
compiler driver in a portable way. -
The “Swift_MODULE_DIRECTORY” target property now supports “generator
expressions”. -
The “VS_CUSTOM_COMMAND_DISABLE_PARALLEL_BUILD” source file property
was added to tell Visual Studio Generators not to run a custom
command in parallel. -
The “VS_SOLUTION_ITEMS” directory property was added to tell Visual
Studio Generators to attach files directly to the Solution (“.sln”).
Modules
-
The “ExternalData” module gained a “ExternalData_HTTPHEADERS”
variable to specify HTTP headers. -
The “ExternalProject” module’s “ExternalProject_Add()” command
gained an “INSTALL_JOB_SERVER_AWARE” option to enable integration of
the GNU Make job server when using an explicit “INSTALL_COMMAND”
with Makefile Generators. -
The “FeatureSummary” module “add_feature_info()” command now
supports full Condition Syntax. See policy “CMP0183”. -
The “FindBISON” module “bison_target()” command gained an “OPTIONS”
option to specify Bison command-line options. -
The “FindCURL” module now provides a “CURL_VERSION” result variable
to match upstream cURL’s CMake package. -
The “FindFLEX” module “flex_target()” command gained an “OPTIONS”
option to specify Flex command-line options. -
The “FindPatch” module now supports running in cmake -P script mode
by skipping the creation of the imported target. -
The “FindProtobuf” module “protobuf_generate()” command gained a
“PROTOC_EXE” option to specify a custom “protoc” executable. -
The “FindPython”, “FindPython2”, and “FindPython3” modules gained
the possibility to do multiple calls in the same directory by using,
respectively, the variables “Python_ARTIFACTS_PREFIX”,
“Python2_ARTIFACTS_PREFIX”, and “Python3_ARTIFACTS_PREFIX”. -
The “FindRuby” module learned to find rbenv-provided installations.
Generator Expressions
- The “$<PATH>” generator expression gained the “NATIVE_PATH”
operation to convert a CMake path into a native one.
CTest
- The “ctest --interactive-debug-mode” option on Windows now enables
Windows Error Reporting by default in test processes, allowing them
to creating debug popup windows and core dumps. This restores
behavior previously removed by CMake 3.11 after updates to “libuv”
made it possible.
CPack
-
The “CPack Archive Generator” learned to generated “.tar” packages
without compression. -
The “CPack Archive Generator” now honors the
“CPACK_ARCHIVE_FILE_NAME” variable for all packages. Previously,
this variable worked only for component-based packages.
Deprecated and Removed Features
-
Compatibility with versions of CMake older than 3.5 has been
removed. Calls to “cmake_minimum_required()” or “cmake_policy()”
that set the policy version to an older value now issue an error.
Note that calls to those commands can still support older versions
of CMake by using their “VERSION” arguments’ “<min>…<max>” syntax.
This requires only the “<min>” version of CMake, but when running a
newer version, sets policies up to the “<max>” version. -
The “Visual Studio 14 2015” and “Visual Studio 15 2017” generators
no longer support specifying a platform as part of the generator
name. See Visual Studio Platform Selection. -
The “CMAKE_<LANG>USING_LINKER_MODE" variable is no longer used to
determine the type of the contents of the
"CMAKE<LANG>USING_LINKER<TYPE>” variable. The
“CMAKE_<LANG>_LINK_MODE” variable, set by CMake, is used instead. -
The “FindGDAL” module is now deprecated in favor of upstream GDAL’s
official CMake package configuration file. Port projects to the
latter by calling “find_package(GDAL CONFIG)”. For further details,
see GDAL’s documentation on CMake integration. -
The “FindRuby” module no longer provides variables with the upper-
case “RUBY_” prefix. See policy “CMP0185”. -
CTest’s undocumented declarative scripting mode has been removed.
This mode used to be triggered by a “ctest -S” script which did not
call any CTest Commands unless “CTEST_RUN_CURRENT_SCRIPT” was
explicitly set to “OFF”. -
The “ctest_run_script()” command may no longer be called without any
arguments.
Other Changes
-
On macOS with Ninja Generators and Makefile Generators, when a
compiler is found in “/usr/bin”, it is now used as-is and is no
longer mapped to the corresponding compiler inside Xcode. The
mapping was introduced by CMake 3.2 to allow build trees to continue
to work with their original compiler even when “xcode-select”
switches to a different Xcode installation. However, the compilers
inside Xcode cannot be used without explicit “-isysroot” flags and
are therefore not suitable for passing to arbitrary third-party
build systems. Furthermore, the mapping behavior can override user-
specified compiler paths. Therefore, this behavior has been
reverted. -
Builds targeting macOS no longer choose any SDK or pass an
“-isysroot” flag to the compiler by default. Instead, compilers are
expected to choose a default macOS SDK on their own. In order to
use a compiler that does not do this, users must now specify
“-DCMAKE_OSX_SYSROOT=macosx” when configuring their build. -
On AIX, “SHARED” library targets now produce a shared library
archive by default. See policy “CMP0182”. -
The “cmake --preset” command no longer outputs a summary of the
preset’s CMake cache and environment variables by default. That
summary is now only shown when the message log level is set to
“VERBOSE”, “DEBUG”, or “TRACE” via the “cmake --log-level” option
or the “CMAKE_MESSAGE_LOG_LEVEL” cache variable. -
Precompiled SunOS “sparc” and “i386” binaries are now provided on
cmake.org.
Changes made since CMake 4.0.0-rc1:
Brad King (18):
- Help: add_dependencies requires at least two arguments
- gitattributes: Do not export pre-commit config file in source archives
- clang-tidy: Do not require config file if not running clang-tidy
- Tests: Cover CMAKE_POLICY_VERSION_MINIMUM as cache entry
- Tests: Cover CMAKE_POLICY_VERSION_MINIMUM in script mode
- Tests: Cover CMAKE_POLICY_VERSION_MINIMUM in initial cache script
- Add CMAKE_POLICY_VERSION_MINIMUM environment variable
- Tests: Fix typos in RunCMake.ParseImplicitLinkInfo sample data
- Tests: Make RunCMake.ParseImplicitLinkInfo robust to on-disk libstdc++.a
- cmGeneratorExpressionDAGChecker: Construct with initializer list syntax
- cmGeneratorExpressionDAGChecker: De-duplicate constructor signature
- cmGeneratorExpressionDAGChecker: Construct with initializer list syntax
- Tests: Split CustomTransitiveProperties argument checks into helper
- Tests: Extend CustomTransitiveProperties with non-transitive LINK_LIBRARIES
- Tests: Extend CustomTransitiveProperties with custom transitive LINK_LIBRARIES
- GenEx: Restore evaluation context for conditional transitive properties
- GenEx: Fix evaluation of LINK_LIBRARIES as custom transitive property
- CMake 4.0.0-rc2
Martin Duffy (2):
- CTest: Fix startTime in test snippets when using instrumentation
- instrumentation: Quote command arguments to preserve separation
Matthew Woehlke (1):
- CPS: Fix importing from the prefix root
Roger Leigh (1):
- libuv: Remove kvm dependency for all BSDs except NetBSD