I am proud to announce the fourth CMake 3.16 release candidate.
Documentation is available at:
Release notes appear below and are also published at
Some of the more significant changes in CMake 16 are:
- CMake learned to support the Objective C (“OBJC”) and Objective
- C++ (“OBJCXX”) languages. They may be enabled via the “project()”
and “enable_language()” commands. When “OBJC” or “OBJCXX” is
enabled, source files with the “.m” or “.mm”, respectively, will be
compiled as Objective C or C++. Otherwise they will be treated as
plain C++ sources as they were before.
- The “target_precompile_headers()” command was added to specify a
list of headers to precompile for faster compilation times.
- The “UNITY_BUILD” target property was added to tell generators to
batch include source files for faster compilation times.
- The “find_file()”, “find_library()”, “find_path()”,
“find_package()”, and “find_program()” commands have learned to
check the following variables to control searching
- “CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH” – Controls the searching
the cmake-specific environment variables.
- “CMAKE_FIND_USE_CMAKE_PATH” – Controls the searching the cmake-
specific cache variables.
- “CMAKE_FIND_USE_CMAKE_SYSTEM_PATH” – Controls the searching
cmake platform specific variables.
- “CMAKE_FIND_USE_PACKAGE_ROOT_PATH” – Controls the searching of
- “CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH” – Controls the
searching the standard system environment variables.
- The “file()” command learned a new sub-command,
“GET_RUNTIME_DEPENDENCIES”, which allows you to recursively get the
list of libraries linked by an executable or library. This sub-
command is intended as a replacement for “GetPrerequisites”.
- “ctest(1)” now has the ability to serialize tests based on
resource requirements for each test. See Resource Allocation for
- On AIX, executables using the “ENABLE_EXPORTS” target property now
produce a linker import file with a “.imp” extension in addition to
the executable file. Plugins (created via “add_library()” with the
“MODULE” option) that use “target_link_libraries()” to link to the
executable for its symbols are now linked using the import file. The
“install(TARGETS)” command now installs the import file as an
- On AIX, runtime linking is no longer enabled by default. CMake
provides the linker enough information to resolve all symbols up
front. One may manually enable runtime linking for shared libraries
and/or loadable modules by adding “-Wl,-G” to their link flags (e.g.
in the “CMAKE_SHARED_LINKER_FLAGS” or “CMAKE_MODULE_LINKER_FLAGS”
variable). One may manually enable runtime linking for executables
by adding “-Wl,-brtl” to their link flags (e.g. in the
- “cmake(1)” “-E” now supports “true” and “false” commands, which do
nothing while returning exit codes of 0 and 1, respectively.
- “cmake(1)” gained a “–trace-redirect=” command line option
that can be used to redirect “–trace” output to a file instead of
- The “cmake(1)” “–loglevel” command line option has been renamed
to “–log-level” to make it consistent with the naming of other
command line options. The “–loglevel” option is still supported to
preserve backward compatibility.
- The “CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY” variable has been
deprecated. Use the “CMAKE_FIND_USE_PACKAGE_REGISTRY” variable
- The “GetPrerequisites” module has been deprecated, as it has been
superceded by “file(GET_RUNTIME_DEPENDENCIES)”.
Changes made since CMake 3.15 include the following. New Features ============ Languages --------- * CMake learned to support the Objective C ("OBJC") and Objective C++ ("OBJCXX") languages. They may be enabled via the "project()" and "enable_language()" commands. When "OBJC" or "OBJCXX" is enabled, source files with the ".m" or ".mm", respectively, will be compiled as Objective C or C++. Otherwise they will be treated as plain C++ sources as they were before. Compilers --------- * The "Clang" compiler is now supported on "Solaris". Platforms --------- * On AIX, executables using the "ENABLE_EXPORTS" target property now produce a linker import file with a ".imp" extension in addition to the executable file. Plugins (created via "add_library()" with the "MODULE" option) that use "target_link_libraries()" to link to the executable for its symbols are now linked using the import file. The "install(TARGETS)" command now installs the import file as an "ARCHIVE" artifact. * On AIX, runtime linking is no longer enabled by default. CMake provides the linker enough information to resolve all symbols up front. One may manually enable runtime linking for shared libraries and/or loadable modules by adding "-Wl,-G" to their link flags (e.g. in the "CMAKE_SHARED_LINKER_FLAGS" or "CMAKE_MODULE_LINKER_FLAGS" variable). One may manually enable runtime linking for executables by adding "-Wl,-brtl" to their link flags (e.g. in the "CMAKE_EXE_LINKER_FLAGS" variable). Command-Line ------------ * "cmake(1)" "-E" now supports "true" and "false" commands, which do nothing while returning exit codes of 0 and 1, respectively. * "cmake(1)" gained a "--trace-redirect=" command line option that can be used to redirect "--trace" output to a file instead of "stderr". * The "cmake(1)" "--loglevel" command line option has been renamed to "--log-level" to make it consistent with the naming of other command line options. The "--loglevel" option is still supported to preserve backward compatibility. Commands -------- * The "add_test()" command learned the option "COMMAND_EXPAND_LISTS" which causes lists in the "COMMAND" argument to be expanded, including lists created by generator expressions. * The "file()" command learned a new sub-command, "GET_RUNTIME_DEPENDENCIES", which allows you to recursively get the list of libraries linked by an executable or library. This sub- command is intended as a replacement for "GetPrerequisites". * The "find_file()", "find_library()", "find_path()", "find_package()", and "find_program()" commands have learned to check the following variables to control searching * "CMAKE_FIND_USE_CMAKE_ENVIRONMENT_PATH" - Controls the searching the cmake-specific environment variables. * "CMAKE_FIND_USE_CMAKE_PATH" - Controls the searching the cmake- specific cache variables. * "CMAKE_FIND_USE_CMAKE_SYSTEM_PATH" - Controls the searching cmake platform specific variables. * "CMAKE_FIND_USE_PACKAGE_ROOT_PATH" - Controls the searching of "_ROOT" variables. * "CMAKE_FIND_USE_SYSTEM_ENVIRONMENT_PATH" - Controls the searching the standard system environment variables. * The "find_package()" command has learned to check the following variables to control searching * "CMAKE_FIND_USE_PACKAGE_REGISTRY" - Controls the searching the cmake user registry. * The "message()" command learned indentation control with the new "CMAKE_MESSAGE_INDENT" variable. * The "target_precompile_headers()" command was added to specify a list of headers to precompile for faster compilation times. Variables --------- * The "CMAKE_CUDA_RESOLVE_DEVICE_SYMBOLS" variable has been introduced to optionally initialize the "CUDA_RESOLVE_DEVICE_SYMBOLS" target property. * The "CMAKE_ECLIPSE_RESOURCE_ENCODING" variable was added to specify the resource encoding for the the "Eclipse CDT4" extra generator. Properties ---------- * The "BUILD_RPATH" and "INSTALL_RPATH" target properties now support "generator expressions". * The "INSTALL_REMOVE_ENVIRONMENT_RPATH" target property was added to remove compiler-defined "RPATH" entries from a target. This property is initialized by the "CMAKE_INSTALL_REMOVE_ENVIRONMENT_RPATH" variable. * The "PRECOMPILE_HEADERS" target property was added to specify a list of headers to precompile for faster compilation times. Set it using the "target_precompile_headers()" command. * The "UNITY_BUILD" target property was added to tell generators to batch include source files for faster compilation times. * The "VS_CONFIGURATION_TYPE" target property now supports "generator expressions". * The "VS_DPI_AWARE" target property was added to tell Visual Studio Generators to set the "EnableDpiAwareness" property in ".vcxproj" files. * The "XCODE_SCHEME_DEBUG_DOCUMENT_VERSIONING" target property was added to tell the "Xcode" generator to set the value of the "Allow debugging when using document Versions Browser" schema option. Modules ------- * The "FindDoxygen" module "doxygen_add_docs()" command gained a new "USE_STAMP_FILE" option. When this option present, the custom target created by the command will only re-run Doxygen if any of the source files have changed since the last successful run. * The "FindGnuTLS" module now provides an imported target. * The "FindPackageHandleStandardArgs" module "find_package_handle_standard_args()" command gained a new "REASON_FAILURE_MESSAGE" option to specify a message giving the reason for the failure. * The "FindPkgConfig" module "pkg_search_module()" macro now defines a "_MODULE_NAME" result variable containing the first matching module name. * The "FindPython3" and "FindPython" modules gained options to control which "ABIs" will be searched. * The "FindPython3", "FindPython2", and "FindPython" modules now support direct specification of artifacts via cache entries. Autogen ------- * When using "AUTOMOC", CMake now generates the "-p" path prefix option for "moc". This ensures that "moc" output files are identical on different build setups (given, that the headers compiled by "moc" are in an "include directory"). Also it ensures that "moc" output files will compile correctly when the source and/or build directory is a symbolic link. The "moc" path prefix generation behavior can be configured by setting the new "CMAKE_AUTOMOC_PATH_PREFIX" variable and/or "AUTOMOC_PATH_PREFIX" target property. CTest ----- * "ctest(1)" now has the ability to serialize tests based on resource requirements for each test. See Resource Allocation for details. * A new test property, "SKIP_REGULAR_EXPRESSION", has been added. This property is similar to "FAIL_REGULAR_EXPRESSION" and "PASS_REGULAR_EXPRESSION", but with the same meaning as "SKIP_RETURN_CODE". This is useful, for example, in cases where the user has no control over the return code of the test. For example, in Catch2, the return value is the number of assertion failed, therefore it is impossible to use it for "SKIP_RETURN_CODE". CPack ----- * CPack variable "CPACK_INSTALL_CMAKE_CONFIGURATIONS" was added to control what configurations are to be packaged for multi- configuration CMake generators. * The "CPack DEB Generator" is now able to format generic text (usually used as the description for multiple CPack generators) according to the Debian Policy Manual. See the "CPACK_PACKAGE_DESCRIPTION_FILE" and "CPACK_DEBIAN__DESCRIPTION" variables. * The "CPack Archive Generator" learned to generate ".tar.zst" packages with Zstandard compression. Deprecated and Removed Features =============================== * An explicit deprecation diagnostic was added for policy "CMP0067" ("CMP0066" and below were already deprecated). The "cmake- policies(7)" manual explains that the OLD behaviors of all policies are deprecated and that projects should port to the NEW behaviors. * The "CMAKE_FIND_PACKAGE_NO_PACKAGE_REGISTRY" variable has been deprecated. Use the "CMAKE_FIND_USE_PACKAGE_REGISTRY" variable instead. * The "GetPrerequisites" module has been deprecated, as it has been superceded by "file(GET_RUNTIME_DEPENDENCIES)". * The "CPACK_INSTALL_SCRIPT" variable has been deprecated in favor of the new, more accurately named "CPACK_INSTALL_SCRIPTS" variable. Other Changes ============= * The "cmake(1)" "-C " option now evaluates the initial cache script with "CMAKE_SOURCE_DIR" and "CMAKE_BINARY_DIR" set to the top-level source and build trees. * The "cmake(1)" "-E remove_directory" command-line tool, when given the path to a symlink to a directory, now removes just the symlink. It no longer removes content of the linked directory. * The "ctest(1)" "--build-makeprogram" command-line option now specifies the make program used when configuring a project with the "Ninja" generator or the Makefile Generators. * The "ExternalProject" module "ExternalProject_Add()" command has been updated so that "GIT_SUBMODULES """ initializes no submodules. See policy "CMP0097". * The "FindGTest" module has been updated to recognize MSVC build trees generated by GTest 1.8.1. * The "project()" command no longer strips leading zeros in version components. See policy "CMP0096". * The Qt Compressed Help file is now named "CMake.qch", which no longer contains the release version in the file name. When CMake is upgraded in-place, the name and location of this file will remain constant. Tools such as IDEs, help viewers, etc. should now be able to refer to this file at a fixed location that remains valid across CMake upgrades. * "RPATH" entries are properly escaped in the generated CMake scripts used for installation. See policy "CMP0095". * When using "CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS" on Windows the auto- generated exports are now updated only when the object files providing the symbols are updated. ---------------------------------------------------------------------------- Changes made since CMake 3.16.0-rc3: Alex Turbov (1): CPack: Remove CPACK_INSTALL_CMAKE_CONFIGURATIONS Arkadiusz Drabczyk (1): Tutorial: replace Unicode EN DASH with ASCII dash Ben Boeckel (3): Help: drop confusing reference to `if()` from `$` FindPostgreSQL: support version encoding used in pre-10 releases FindPostgreSQL: also search for libraries in the MacPorts suffix Brad King (20): CTest: Rename PROCESSES test property to RESOURCE_GROUPS CTest: Rename "Processes" lexer to "ResourceGroups" Help/dev: Update maintainer guide for Discourse transition cmGlobalXCodeGenerator: Mark known source locations Xcode: Fix generated references to CMakeLists.txt files CMakeCPack: Update Debian package contact email Help: Replace links to mailing lists with links to our Discourse Forum README: Update links to cmake.org pages README: Replace link to mailing list the CMake Discourse Forum CMakeSystemSpecificInformation: Replace mailing list with Discourse Forum FindBinUtils: Revert "Use the compiler to get the path to compiler tools" Help: Document target_precompile_headers genex with angle brackets CTestCoverageCollectGCOV: Fix typo in ctest_coverage_collect_gcov docs expat: Update script to get Expat 2.2.9 expat: Update CMake build for 2.2.9 Tests: Fix ExportImport PCH expectation on Cray Classic compiler Tests: Add RunCMake.CPackCommandLine case for multi-config package Tests: Organize Objective C/C++ test directories CPack: Restore support for custom package configuration templates CMake 3.16.0-rc4 Charles Barto (1): Help: Clarify load_cache documentation of first parameter Craig Scott (14): ForceToRelativePath: Fix spurious assertion when local path is root dir Help: list(REMOVE_ITEM) removes all instances, not just the first found Help: Typo and grammar fixes for file(GET_RUNTIME_DEPENDENCIES) Tutorial: clean up typos, grammar and formatting RPATH: Remove stray indent in generated file(RPATH_CHANGE) command Help: Fix inaccuracies in INSTALL_REMOVE_ENVIRONMENT_RPATH docs CTest: Rename hardware -> resources for CMake variables, command options cmCTestMultiProcessHandler: Rename resource locking functions CTest: Rename hardware -> resources for source code CTest: Rename hardware -> resources for RunCMake tests Help: Improve readability and fix inaccuracies in unity build docs Help: Reorganise target_precompile_headers() docs for readability Help: Provide guidance on INTERFACE for target_precompile_headers() Help: Clarify compile features handling for OBJC and OBJCXX Craig Sturdy (1): FindwxWidgets: Add support for wxQt Cristian Adam (13): PCH: Add support for OBJC/OBJCXX languages CMakeVersion.rc: Fix build with llvm-rc ObjC: Mark explicitly the language for compilation Unity build: Include GENERATED files into unity build ObjC: Set same settings for all languages supported on Darwin ObjC: Add try_compile support PCH: No repeated path for internal generated PCH files Unity: Don't include sources with HEADER_FILE_ONLY property set ObjC: Document ObjC/ObjCXX standard properties / variables ObjC: Add OBJC/OBJCXX flags to Xcode projects ObjC: Initialize ObjC/XX standard properties from C/C++ counterparts ObjC: Proper initialization of ObjC/XX standard properties PCH: Do not issue an error on duplicate target_precompile_headers call Daniel Eiband (2): cmFileAPI: Resolve full path in PCH source comparison UnityBuild: Resolve full paths of unity source includes Deniz Bahadir (1): FindBoost: Prevent warning due to new meta-component "ALL" of Boost 1.73 Expat Upstream (1): expat 2019-09-25 (a7bc26b6) Grant Kim (1): FindwxWidgets: Add link dependencies for MinGW Kyle Edwards (2): Help: Fix error in resource allocation example Tests: Fix reliance on undefined behavior of cm::optional Marc Aldorasi (2): Help: Reference IMPORTED_IMPLIB from the IMPORTED_LOCATION documentation Help: Both add_custom_command signatures support COMMAND_EXPAND_LISTS Mateusz Janek (1): source_group: ensure that passed file is not a directory Robert Maynard (3): Help: Remove out of date bounds on compile feature supported versions find_package: Add support for CMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY Help: Clarify what 'aware' means as it relates to C++ standards Saleem Abdulrasool (3): Swift: Allow build and installed RPATHs to differ Swift: support `INSTALL_NAME_DIR` on Darwin Swift: support `-rpath` on Darwin Tomasz Słodkowicz (1): FindwxWidgets: Add support for 3.1.3 VS binaries