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”.
* The “CMAKE_ANDROID_NDK_VERSION” variable was added to report the
version of the NDK.
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 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-rc5:
Adriaan de Groot (1):
Help: Fix typos in presets schema field descriptions
Brad King (3):
CMP0118: Fix NEW behavior when looking up target sources
Help: Document CMP0118 requirement for boolean values
CMake 3.20.0
Craig Scott (1):
Help: CMAKE_NO_BUILTIN_CHRPATH applies to XCOFF too
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