# CMake 3.20.0-rc2 is ready for testing
**URL:** https://discourse.cmake.org/t/cmake-3-20-0-rc2-is-ready-for-testing/2835
**Category:** Announcements
**Created:** [February 24, 2021, 7:12pm UTC](https://discourse.cmake.org/t/cmake-3-20-0-rc2-is-ready-for-testing/2835 "2021-02-24T19:12:46Z")
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### Author:  [@Tom\_Osika](https://discourse.cmake.org/u/Tom_Osika)
#### Post date: [February 24, 2021, 7:12pm UTC](https://discourse.cmake.org/t/cmake-3-20-0-rc2-is-ready-for-testing/2835/1 "2021-02-24T19:12:46Z")
I am proud to announce the second CMake 3.20 release candidate.
[https://cmake.org/download/](https://cmake.org/download/)
Documentation is available at:
[https://cmake.org/cmake/help/v3.20](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](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:
- 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.
- 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”:
- 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:
### 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.
- 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\_\\_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 “\\_CLANG\_TIDY” target property and the associated
“CMAKE\_\\_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 \” 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:
## 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\_\\_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:
## 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](https://cmake.org/download/) have changed
their naming pattern to “cmake-$ver-linux-$arch”, where “$arch” is
either “x86\_64” or “aarch64”.
- The precompiled Windows binaries provided on [cmake.org](https://cmake.org/download/) have changed
their naming pattern to “cmake-$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 \’ form of the argument
- cmake: Add support for ‘–build --prefix=\’ form of the argument
- ctest: Add support for ‘–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