CMake 3.20.0-rc2 is ready for testing
February 24, 2021
I am proud to announce the second CMake 3.20 release candidate.
https://cmake.org/download/
Documentation is available at:
https://cmake.org/cmake/help/v3.20
Release notes appear below and are also published at
https://cmake.org/cmake/help/v3.20/release/3.20.html
Some of the more significant changes in CMake 3.20 are:
- “cmake-presets(7)” gained support for build and test presets.
- C++23 compiler modes may now be specified via the “CXX_STANDARD”,
“CUDA_STANDARD”, or “OBJCXX_STANDARD” target properties, or via the
“Compile Features” functionality’s “cxx_std_23” meta-feature. - The NVIDIA HPC SDK compilers are now supported with compiler id
“NVHPC”. - CMake’s support for Cross Compiling for Android is now merged with
the Android NDK’s toolchain file. They now have similar behavior,
though some variable names differ. User-facing changes include:- “find_*” functions will search NDK ABI / API specific paths by
default. - The default “CMAKE_BUILD_TYPE” for Android is now
“RelWithDebInfo”.
- “find_*” functions will search NDK ABI / API specific paths by
- The “cmake-file-api(7)” gained a new “toolchains” object kind that
describes the compiler used for each enabled language. - “add_custom_command()” and “add_custom_target()” now support
“generator expressions” in their “OUTPUT” and “BYPRODUCTS” options.Their “COMMAND”, “WORKING_DIRECTORY”, and “DEPENDS” options gained
support for new generator expressions “$<COMMAND_CONFIG:…>” and
“$<OUTPUT_CONFIG:…>” that control cross-config handling when using
the “Ninja Multi-Config” generator. - The “cmake_path()” command was added for operations on filesystem
paths. - The “target_sources()” command now supports targets created by the
“add_custom_target()” command. - The “ExternalProject” module “ExternalProject_Add()” function gained
a “CONFIGURE_HANDLED_BY_BUILD” option. This can be used to make
subsequent runs of the configure step be triggered by the build step
when an external project dependency rebuilds instead of always re-
running the configure step in such cases. - “ctest(1)” gained a “–test-dir” option to specify the directory in
which to look for tests. - The “cmake-server(7)” mode has been removed. Clients should use the
“cmake-file-api(7)” instead. - The “WriteCompilerDetectionHeader” module has been deprecated via
policy “CMP0120”. Projects should be ported away from it. - The “AddFileDependencies” module is deprecated. Port projects to use
“set_property()” directly.
CMake 3.20 Release Notes ************************ Changes made since CMake 3.19 include the following. New Features ============ Presets ------- * "cmake-presets(7)" gained support for build and test presets. Generators ---------- * Makefile Generators, for some toolchains, now use the compiler to extract implicit dependencies while compiling source files. Languages --------- * C++23 compiler modes may now be specified via the "CXX_STANDARD", "CUDA_STANDARD", or "OBJCXX_STANDARD" target properties, or via the "Compile Features" functionality’s "cxx_std_23" meta-feature. * "CUDA" language support now works when "nvcc" is a symbolic link, for example due to a "ccache" or "colornvcc" wrapper script. * The "CUDAARCHS" environment variable was added for initializing "CMAKE_CUDA_ARCHITECTURES". Useful in cases where the compiler default is unsuitable for the machine’s GPU. Compilers --------- * The NVIDIA HPC SDK compilers are now supported with compiler id "NVHPC". * The Intel oneAPI NextGen LLVM compilers are now supported with compiler id "IntelLLVM": * The "icx"/"icpx" C/C++ compilers on Linux, and the "icx" C/C++ compiler on Windows, are fully supported as of oneAPI 2021.1. * The "ifx" Fortran compiler on Linux is partially supported. As of oneAPI 2021.1, "ifx" does not define several identification macros, so CMake identifies it as the classic "Intel" compiler. This works in many cases because "ifx" accepts the same command line parameters as "ifort". A future version of oneAPI may fix this. * The "ifx" Fortran compiler on Windows is not yet supported. The Intel oneAPI Classic compilers ("icc", "icpc", and "ifort") continue to be supported with compiler id "Intel". * Support was added for the IAR STM8 compiler. Platforms --------- * CMake’s support for Cross Compiling for Android is now merged with the Android NDK’s toolchain file. They now have similar behavior, though some variable names differ. User-facing changes include: * "find_*" functions will search NDK ABI / API specific paths by default. * The default "CMAKE_BUILD_TYPE" for Android is now "RelWithDebInfo". File-Based API -------------- * The "cmake-file-api(7)" gained a new “toolchains” object kind that describes the compiler used for each enabled language. Commands -------- * "add_custom_command()" and "add_custom_target()" now support "generator expressions" in their "OUTPUT" and "BYPRODUCTS" options. Their "COMMAND", "WORKING_DIRECTORY", and "DEPENDS" options gained support for new generator expressions "<COMMAND_CONFIG:...>" and "<OUTPUT_CONFIG:...>" that control cross-config handling when using the "Ninja Multi-Config" generator. * The "add_custom_command()" command gained "DEPFILE" support on Makefile Generators. * The "add_library()" command previously prohibited imported object libraries when using potentially multi-architecture configurations. This mostly affected the "Xcode" generator, e.g. when targeting iOS or one of the other device platforms. This restriction has now been removed. * The "cmake_path()" command was added for operations on filesystem paths. * The "configure_file()" command gained "USE_SOURCE_PERMISSIONS" and "FILE_PERMISSIONS" options to support copying of permissions of the source file and using specified permissions respectively. * The "file(GENERATE)" command gained a "NEWLINE_STYLE" option to specify how newlines are handled for the generated file. * The "file(GENERATE)" command gained "NO_SOURCE_PERMISSIONS", "USE_SOURCE_PERMISSIONS", and "FILE_PERMISSIONS" options for controlling the permissions of the generated file. * The "install(FILES)" command "RENAME" option learned to support "generator expressions". * The "target_include_directories()" command gained a new option "AFTER". * The "target_sources()" command now supports targets created by the "add_custom_target()" command. * The "try_run()" command gained a "WORKING_DIRECTORY" option to set the working directory in which to run the compiled check executable. Variables --------- * The "CMAKE_<LANG>_BYTE_ORDER" variable was added to provide the target architecture byte order detected from the toolchain. * The "CMAKE_RUNTIME_OUTPUT_DIRECTORY", "CMAKE_LIBRARY_OUTPUT_DIRECTORY", and "CMAKE_ARCHIVE_OUTPUT_DIRECTORY" variables now support target- dependent generator expressions. Properties ---------- * The "<LANG>_CLANG_TIDY" target property and the associated "CMAKE_<LANG>_CLANG_TIDY" variable learned to support the "OBJC" and "OBJCXX" languages. * The "EXPORT_COMPILE_COMMANDS" target property was added for the associated "CMAKE_EXPORT_COMPILE_COMMANDS" variable to allow for configuration of exporting compile commands per target. * The "GENERATED" source-file property is now visible from any directory scope, regardless of the scope in which it is set. See policy "CMP0118". * The "UNITY_BUILD_UNIQUE_ID" target property was added to support generation of an identifier that is unique per source file in unity builds. It can help to resolve duplicate symbol problems with anonymous namespaces. * The "WIN32_EXECUTABLE" target property now works with Clang on Windows. * The "XCODE_EMBED_FRAMEWORKS" target property was added to tell the "Xcode" generator to embed frameworks. Aspects of the embedding can be customized with the "XCODE_EMBED_FRAMEWORKS_PATH", "XCODE_EMBED_FRAMEWORKS_CODE_SIGN_ON_COPY", and "XCODE_EMBED_FRAMEWORKS_REMOVE_HEADERS_ON_COPY" target properties. Modules ------- * The "ExternalData" module "ExternalData_Add_Target()" function gained a "SHOW_PROGRESS <bool>" option for controlling whether or not to show progress output during the build. * The "ExternalProject" module "ExternalProject_Add()" function gained a "CONFIGURE_HANDLED_BY_BUILD" option. This can be used to make subsequent runs of the configure step be triggered by the build step when an external project dependency rebuilds instead of always re- running the configure step in such cases. * The "FindBoost" module gained a "Boost_NO_WARN_NEW_VERSIONS" option to silence the warning about unknown dependencies for new Boost versions. * The "FindCUDAToolkit" module gained support for finding CUDA toolkits when "nvcc" is a symbolic link, for example due to a "ccache" or "colornvcc" wrapper script. * The "FindGDAL" module has been improved to document and mark as advanced its cache variables. There is a new "FindGDAL_SKIP_GDAL_CONFIG" variable which may be used to skip over the "gdal-config"-based search. Users may also set "GDAL_ADDITIONAL_LIBRARY_VERSIONS" to add additional versions to the library name search strategy. * The "FindIntl" module now provides an imported target. * The "FindOpenSSL" module learned to support a version range. * The "FindPython3", "FindPython2" and "FindPython" modules gained options controlling how unversioned interpreter names are searched. * The "UseJava" module "add_jar()" command’s "GENERATE_NATIVE_HEADERS" feature gained options to export the generated target. * The "UseSWIG" module gained the capability, for Makefile and Ninja generators, to use the "swig" tool to generate implicit dependencies. Autogen ------- * The AUTOMOC feature now works with per-config sources. CTest ----- * "ctest(1)" gained a "--test-dir" option to specify the directory in which to look for tests. CPack ----- * "CPack" gained the "CPACK_THREADS" variable to control the number of threads used for parallelized operations, such as compressing the installer package. * The "CPack DEB Generator" learned a new "CPACK_DEBIAN_PACKAGE_SHLIBDEPS_PRIVATE_DIRS" variable to specify additional search directories for resolving private library dependencies when using "dpkg-shlibdeps". * The "CPack IFW Generator" gained a new "CPACK_IFW_PACKAGE_WIZARD_SHOW_PAGE_LIST" variable to control visibility of the widget listing installer pages on the left side of the wizard. This feature available only since QtIFW 4.0. * The "CPack NSIS Generator" gained new "CPACK_NSIS_BRANDING_TEXT" and "CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION" variables to change the text at the bottom of the install window and change its trim position * The "CPack NSIS Generator" now correctly handles Unicode characters. If you want to have a "CPACK_RESOURCE_FILE_LICENSE" with UTF-8 characters, it needs to be encoded in UTF-8 BOM. * The "CPack NuGet Generator" gained options: * "CPACK_NUGET_PACKAGE_ICON" and "CPACK_NUGET_<compName>_PACKAGE_ICON" allow package icons to be specified by local files. * "CPACK_NUGET_PACKAGE_LICENSE_EXPRESSION" and "CPACK_NUGET_<compName>_PACKAGE_LICENSE_EXPRESSION" add support for specifying licenses recognized by the Software Package Data Exchange (SPDX). * "CPACK_NUGET_PACKAGE_LICENSE_FILE_NAME" and "CPACK_NUGET_<compName>_PACKAGE_LICENSE_FILE_NAME" allow licenses to be specified by local files. * "CPACK_NUGET_PACKAGE_LANGUAGE" and "CPACK_NUGET_<compName>_PACKAGE_LANGUAGE" allow the locale for a package to be specified, for example "en_CA". Deprecated and Removed Features =============================== * The "cmake-server(7)" mode has been removed. Clients should use the "cmake-file-api(7)" instead. * The "WriteCompilerDetectionHeader" module has been deprecated via policy "CMP0120". Projects should be ported away from it. * The "TestBigEndian" module has been deprecated in favor of the "CMAKE_<LANG>_BYTE_ORDER" variable. * The "AddFileDependencies" module is deprecated. Port projects to use "set_property()" directly. * The "CPack NuGet Generator" deprecated some variables to reflect changes in the NuGet specification: * "CPACK_NUGET_PACKAGE_ICONURL" and "CPACK_NUGET_<compName>_PACKAGE_ICONURL" have been deprecated; replace with a reference to a local icon file. * "CPACK_NUGET_PACKAGE_LICENSEURL" and "CPACK_NUGET_<compName>_PACKAGE_LICENSEURL" have been deprecated; replace with a reference to the project’s license file or SPDX license expression. Other Changes ============= * Source file extensions must now be explicit. See policy "CMP0115" for details. * The "LANGUAGE" source file property now forces compilation as the specified language. See policy "CMP0119". * On AIX, installation of XCOFF executables and shared libraries no longer requires relinking to change the runtime search path from the build-tree RPATH to the install-tree RPATH. CMake now edits the XCOFF binaries directly during installation, as has long been done on ELF platforms. * With MSVC-like compilers the value of "CMAKE_CXX_FLAGS" no longer contains the "/GR" flag for runtime type information by default. See policy "CMP0117". * Ninja generators now transform the "DEPFILE" generated by an "add_custom_command()". See policy "CMP0116" for details. * The implementation of the "ExternalProject" module was significantly refactored. The patch step gained support for using the terminal with a new "USES_TERMINAL_PATCH" keyword as a by-product of that work. * The "FetchContent" module no longer creates a separate sub-build to implement the content population. It now invokes the step scripts directly from within the main project’s configure stage. This significantly speeds up the configure phase when the required content is already populated and up-to-date. * The precompiled Linux binaries provided on cmake.org have changed their naming pattern to "cmake-$ver-linux-$arch", where "$arch" is either "x86_64" or "aarch64". * The precompiled Windows binaries provided on cmake.org have changed their naming pattern to "cmake-$ver-windows-$arch", where "$arch" is either "x86_64" or "i386". ---------------------------------------------------------------------------- Changes made since CMake 3.20.0-rc1: Brad King (25): Intel: Make explicit Fortran preprocessing under Ninja more robust IntelLLVM: Make explicit Fortran preprocessing under Ninja more robust bindexplib: remove stray debugging output when using llvm-nm Utilities/Sphinx: Avoid converting -- to an en-dash Help: Mention version 2 in cmake-presets(7) Help: Link to tool-specific preset arguments from cmake-presets(7) Help: Clarify role of binaryDir inheritance in cmake-presets(7) Help: Fix CPACK_DEBIAN_PACKAGE_SHLIBDEPS_PRIVATE_DIRS documentation cmVisualStudio10TargetGenerator: Refactor per-source PCH logic VS: Restore support for PCH in CXX but not C within once target NAG: Fix using Fortran modules from their output directory Tests: Clarify internal project name in RunCMake.GoogleTest cases Tests: Remove explicit no-signing marks from BundleTest Tests: Fix CTestTestCrash expected output on macOS arm64 Tests: Suppress failures on macOS arm64 due to separate Xcode signing phase cmake: Document '--preset <preset>' form of the argument cmake: Add support for '--build --prefix=<prefix>' form of the argument ctest: Add support for '--prefix=<prefix>' form of the argument ci: Use Qt macOS 10.13+ package for macOS build and test jobs ci: update to sccache 0.2.15 on linux builds Tests: Update for upstream ninja change to write status on stderr ci: add sccache 0.2.15 custom build for aarch64-apple-darwin gitlab-ci: rename macos build and test jobs to macos-x86_64 gitlab-ci: Add macos-arm64 jobs for Ninja and Xcode CMake 3.20.0-rc2 Craig Scott (5): FetchContent: Restore patch command support CPackIFWInstaller: Avoid potential null pointer dereference Autogen: Don't change the order of HEADERS array in AutogenInfo.json ExternalProject: Fix misuse of IS_NEWER_THAN in timestamp checks FetchContent: Don't update timestamps if files don't change Daan De Meyer (1): Tests: Fix ExternalProject CONFIGURE_HANDLED_BY_BUILD on 1s filesystems Gregor Jasny (1): DetermineCompiler: Fix copy-paste error in Intel Compiler detection Kyle Edwards (7): cmCustomCommand: Record value of CMP0116 at time of creation Ninja: Use CMP0116 status recorded at time of custom command's creation Tests: Test per-CC behavior of CMP0116 Tests: Test Qt autogen target with CMP0116 set to WARN Help: Note that CMP0116 is recorded at the time of CC creation CMakePresets.json: Remove undocumented support for comments Tests: Remove comments from CMakePresetsTest/Good.json.in Marc Chevrier (1): Genex: LINK_LANGUAGE respects LINKER_LANGUAGE property Michael Hirsch (2): Help: Clarify preset name conflict rules in cmake-presets(7) Help: Add build and test preset to examples in cmake-presets(7) Michael Hirsch, Ph.D (1): Help: Add internal links to if() docs Robert Maynard (1): CUDA: Improve error messages when CUDA compiler detection fails Sankhesh Jhaveri (1): cmake-gui: Restore search bar for cache view and environment dialog