CMake 3.19.0-rc3 is ready for testing

I am proud to announce the second CMake 3.19 release candidate.
https://cmake.org/download/

The first two 3.19.0 release candidates included the “cmake_path()”
command. This has been removed in rc3 pending further development.

Documentation is available at:
https://cmake.org/cmake/help/v3.19

Release notes appear below and are also published at
https://cmake.org/cmake/help/v3.19/release/3.19.html

Some of the more significant changes in CMake 3.19 are:

• “cmake(1)” and “cmake-gui(1)” now recognize “CMakePresets.json” and
  “CMakeUserPresets.json” files (see “cmake-presets(7)”).
• The “Xcode” generator now uses the Xcode “new build system” when
  generating for Xcode 12.0 or higher. See the
  “CMAKE_XCODE_BUILD_SYSTEM” variable. One may use “-T buildsystem=1”
  to switch to the legacy build system.
• The Visual Studio Generators for VS 2015 and above gained support
  for the Visual Studio Tools for Android. One may now set
  “CMAKE_SYSTEM_NAME” to “Android” to generate “.vcxproj” files for
  the Android tools.
• CMake learned to support “ISPC” as a first-class language that can
  be enabled via the “project()” and “enable_language()” commands.
  “ISPC” is currently supported by the Makefile Generators and the
  “Ninja” generator on Linux, macOS, and Windows using the Intel ISPC
  compiler.
• “CUDA” language support for Clang now supports separable compilation
  (“CUDA_SEPARABLE_COMPILATION”)
• The “CMake GUI” now has an environment variable editor.
• The “file(GENERATE)” command gained a new “TARGET” keyword to
  support resolving target-dependent generator expressions.
• The “CMAKE_OPTIMIZE_DEPENDENCIES” variable was added to initialize
  the new “OPTIMIZE_DEPENDENCIES” target property and avoid
  unnecessarily building dependencies for a static library.
• The “CheckCompilerFlag” module has been added to generalize
  “CheckCCompilerFlag” and “CheckCXXCompilerFlag” to more languages.
  It also supports the “CUDA” and “ISPC” languages.
• The “CheckSourceCompiles” module has been added to generalize
  “CheckCSourceCompiles” and “CheckCXXSourceCompiles” to more
  languages. It also supports the “CUDA” and “ISPC” languages.
• The “CheckSourceRuns” module has been added to generalize
  “CheckCSourceRuns” and “CheckCXXSourceRuns” to more languages. It
  also supports the “CUDA” language.
• The “FindCUDAToolkit” module gained support for finding CUDA
  toolkits that do not contain “nvcc”, as well as for finding
  scattered toolkit installations when cross-compiling.
• Interface Libraries may now have source files added via
  “add_library()” or “target_sources()”. Those with sources will be
  generated as part of the build system.
• Compatibility with versions of CMake older than 2.8.12 is now
  deprecated and will be removed from a future version. Calls to
  “cmake_minimum_required()” or “cmake_policy()” that set the policy
  version to an older value now issue a deprecation diagnostic.

----------------------------------------------------------------------------
CMake 3.19 Release Notes
************************

Changes made since CMake 3.18 include the following.


New Features
============


Presets
-------

* "cmake(1)" and "cmake-gui(1)" now recognize "CMakePresets.json" and
  "CMakeUserPresets.json" files (see "cmake-presets(7)").


Generators
----------

* The "Xcode" generator now uses the Xcode “new build system” when
  generating for Xcode 12.0 or higher. See the
  "CMAKE_XCODE_BUILD_SYSTEM" variable. One may use "-T buildsystem=1"
  to switch to the legacy build system.

* The "Xcode" generator gained support for linking libraries and
  frameworks via the *Link Binaries With Libraries* build phase
  instead of always by embedding linker flags directly.  This behavior
  is controlled by a new "XCODE_LINK_BUILD_PHASE_MODE" target
  property, which is initialized by a new
  "CMAKE_XCODE_LINK_BUILD_PHASE_MODE" variable.

* The Visual Studio Generators for VS 2015 and above gained support
  for the Visual Studio Tools for Android.  One may now set
  "CMAKE_SYSTEM_NAME" to "Android" to generate ".vcxproj" files for
  the Android tools.


Languages
---------

* CMake learned to support "ISPC" as a first-class language that can
  be enabled via the "project()" and "enable_language()" commands.
  "ISPC" is currently supported by the Makefile Generators and the
  "Ninja" generator on Linux, macOS, and Windows using the Intel ISPC
  compiler.

* "CUDA" language support for Clang now includes:

  * separable compilation ("CUDA_SEPARABLE_COMPILATION"), and

  * finding scattered toolkit installations when cross-compiling.


File-Based API
--------------

* The "cmake-file-api(7)" “codemodel” version 2 "version" field has
  been updated to 2.2.

* The "cmake-file-api(7)" “codemodel” version 2 “target” object gained
  a new "languageStandard" field in the "compileGroups" objects.


Command-Line
------------

* The "cmake(1)" command-line tool’s "--install" mode gained a "--
  default-directory-permissions" option.

* "cmake(1)" gained a "-E create_hardlink" command-line tool that can
  be used to create hardlinks between files.


GUI
---

* The "CMake GUI" now has an environment variable editor.


Commands
--------

* The "add_test()" command now (officially) supports whitespace and
  other special characters in the name for the test it creates. See
  policy "CMP0110".

* The "cmake_language()" command gained a "DEFER" mode to schedule
  command calls to occur at the end of processing a directory.

* The "configure_file()" command gained a "NO_SOURCE_PERMISSIONS"
  option to suppress copying the input file’s permissions to the
  output file.

* The "execute_process()" command gained a "COMMAND_ERROR_IS_FATAL"
  option to specify a fatal error.

* The "file(ARCHIVE_CREATE)" command gained a "COMPRESSION_LEVEL"
  option to specify the compression level.

* The "file(CHMOD)" and "file(CHMOD_RECURSE)" subcommands were added
  to set permissions of files and directories.

* The "file(DOWNLOAD)" command "" argument is now optional.  If
  it is not specified, the file is not saved.

* The "file(GENERATE)" command gained a new "TARGET" keyword to
  support resolving target-dependent generator expressions.

* The "file()" command gained a new "REAL_PATH" sub-command to compute
  a path with symlinks resolved.

* The "find_package()" command learned to handle a version range.

* The "separate_arguments()" command gained a new "PROGRAM" option. It
  allows the arguments to be treated as a program invocation and will
  resolve the executable to a full path if it can be found.

* The "DIRECTORY" option of the "set_property()", "get_property()",
  and "get_directory_property()" commands now accepts references to
  binary directory paths, such as the value of
  "CMAKE_CURRENT_BINARY_DIR".

* The "string()" command gained a set of new "JSON" sub commands that
  provide JSON parsing capabilities.


Variables
---------

* The "CMAKE_CLANG_VFS_OVERLAY" variable was added to tell Clang to
  use a VFS overlay to support the Windows SDK when cross-compiling
  from hosts with case-sensitive filesystems.

* The "CMAKE_MFC_FLAG" variable now supports generator expressions.

* The "CMAKE_OPTIMIZE_DEPENDENCIES" variable was added to initialize
  the new "OPTIMIZE_DEPENDENCIES" target property and avoid
  unnecessarily building dependencies for a static library.

* The "CMAKE_PCH_INSTANTIATE_TEMPLATES" variable was added to
  initialize the new "PCH_INSTANTIATE_TEMPLATES" target property.

* The "CMAKE_VS_WINDOWS_TARGET_PLATFORM_VERSION_MAXIMUM" variable was
  added to tell the Visual Studio Generators what maximum version of
  the Windows SDK to choose.


Properties
----------

* The "EXCLUDE_FROM_ALL" target property now supports "generator
  expressions".

* The "OPTIMIZE_DEPENDENCIES" target property was added to avoid
  unnecessarily building dependencies for a static library.

* The "PCH_INSTANTIATE_TEMPLATES" target property was added to enable
  template instantiation in the precompiled header. This is enabled by
  default and may significantly improve compile times. Currently only
  supported for Clang (version 11 or later).

* The "WIN32_EXECUTABLE" target property now supports "generator
  expressions".


Modules
-------

* The "CheckCompilerFlag" module has been added to generalize
  "CheckCCompilerFlag" and "CheckCXXCompilerFlag" to more languages.
  It also supports the "CUDA" and "ISPC" languages.

* The "CheckLinkerFlag" module now supports the "CUDA" language.

* The "CheckSourceCompiles" module has been added to generalize
  "CheckCSourceCompiles" and "CheckCXXSourceCompiles" to more
  languages. It also supports the "CUDA" and "ISPC" languages.

* The "CheckSourceRuns" module has been added to generalize
  "CheckCSourceRuns" and "CheckCXXSourceRuns" to more languages. It
  also supports the "CUDA" language.

* The "CMakePackageConfigHelpers" module gained support for version
  ranges.

* The "FindCUDAToolkit" module gained support for finding CUDA
  toolkits that do not contain "nvcc", as well as for finding
  scattered toolkit installations when cross-compiling.

* The "FindPackageHandleStandardArgs" module learned to handle version
  ranges. It also gained the "find_package_check_version()" command to
  check the validity of a version against version-related arguments of
  "find_package()" command.

* The "FindPython3", "FindPython2" and "FindPython" modules gained the
  ability to handle a version range.

* The "FindPython3", "FindPython2" and "FindPython" modules provide,
  respectively, the variable "Python3_LINK_OPTIONS",
  "Python2_LINK_OPTIONS" and "Python_LINK_OPTIONS" for link options.

* The "FindSDL" module now provides:

  * An imported target "SDL::SDL".

  * Result variables "SDL_LIBRARIES" and "SDL_INCLUDE_DIRS".

  * Version variables "SDL_VERSION", "SDL_VERSION_MAJOR",
    "SDL_VERSION_MINOR", and "SDL_VERSION_PATCH".

* The "FindSWIG" module gained the ability to handle a version range.

* The "FindTIFF" module gained a "CXX" component to find the "tiffxx"
  library containing C++ bindings.

* The "FindVulkan" module now provides a "Vulkan::glslc" imported
  target and associated "Vulkan_GLSLC_EXECUTABLE" variable which
  contain the path to the GLSL SPIR-V compiler.

* The "UseSWIG" module gained support for new source file properties
  "OUTPUT_DIR" and "OUTFILE_DIR" to manage output directories on a
  per-source basis.


CTest
-----

* "ctest(1)" now supports the CUDA "compute-sanitizer" checker
  (previously known as "cuda-memcheck") as the
  "CTEST_MEMORYCHECK_COMMAND". The different tools ("memcheck",
  "racecheck", "synccheck" and "initcheck") supported by "compute-
  sanitizer" can be selected by adding appropriate flags to the
  "CTEST_MEMORYCHECK_COMMAND_OPTIONS" variable.  The default flags are
  "--tool memcheck --leak-check full".


CPack
-----

* CPack gained the "CPACK_PRE_BUILD_SCRIPTS",
  "CPACK_POST_BUILD_SCRIPTS", and "CPACK_PACKAGE_FILES" variables.

* The "CPack External Generator" gained the
  "CPACK_EXTERNAL_BUILT_PACKAGES" variable.

* The "CPack WIX Generator" gained a "CPACK_WIX_CUSTOM_XMLNS" option
  to specify custom XML namespaces.


Other
-----

* Interface Libraries may now have source files added via
  "add_library()" or "target_sources()".  Those with sources will be
  generated as part of the build system.


Deprecated and Removed Features
===============================

* Compatibility with versions of CMake older than 2.8.12 is now
  deprecated and will be removed from a future version.  Calls to
  "cmake_minimum_required()" or "cmake_policy()" that set the policy
  version to an older value now issue a deprecation diagnostic.

* An explicit deprecation diagnostic was added for policy "CMP0071"
  ("CMP0071" 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.

* macOS SDKs older than 10.5 are no longer supported.

* "cmake-gui(1)" now requires Qt5. Support for compiling with Qt4 has
  been removed.

* The "cmake(1)" command-line option "--warn-unused-vars" has been
  removed and is now silently ignored.  The option has not worked
  correctly since CMake 3.3.


Documentation
=============

The following guides have been added:

* "IDE Integration Guide"

* "Importing and Exporting Guide"


Other Changes
=============

* Building for macOS will now use the latest SDK available on the
  system, unless the user has explicitly chosen a SDK using
  "CMAKE_OSX_SYSROOT".  The deployment target or system macOS version
  will not affect the choice of SDK.

* The "CMAKE__COMPILER" variable may now be used to store
  “mandatory” compiler flags like the "CC" and other environment
  variables.

* The "CMAKE__FLAGS_INIT" variable will now be considered during
  the compiler identification check if other sources like
  "CMAKE__FLAGS" or "CFLAGS" are not set.

* The "find_program()" command now requires permission to execute but
  not to read the file found.  See policy "CMP0109".

* An imported target missing its location property fails during
  generation if the location is used.  See policy "CMP0111".

* The following target-based generator expressions that query for
  directory or file name components no longer add a dependency on the
  evaluated target. See policy "CMP0112".

  * "TARGET_FILE_DIR"

  * "TARGET_LINKER_FILE_BASE_NAME"

  * "TARGET_LINKER_FILE_NAME"

  * "TARGET_LINKER_FILE_DIR"

  * "TARGET_SONAME_FILE_NAME"

  * "TARGET_SONAME_FILE_DIR"

  * "TARGET_PDB_FILE_NAME"

  * "TARGET_PDB_FILE_DIR"

  * "TARGET_BUNDLE_DIR"

  * "TARGET_BUNDLE_CONTENT_DIR"

* Makefile Generators no longer repeat custom commands from target
  dependencies.  See policy "CMP0113".

* The "ExternalProject" module handling of step target dependencies
  has been revised.  See policy "CMP0114".

* The "OSX_ARCHITECTURES" target property is now respected for the
  "ASM" language.

* If "CUDA" compiler detection fails with user-specified
  "CMAKE_CUDA_ARCHITECTURES" or "CMAKE_CUDA_HOST_COMPILER", an error
  is raised.


----------------------------------------------------------------------------
Changes made since CMake 3.19.0-rc2:

Ben Boeckel (1):
  CheckSourceRuns: do not fail on unrecognized arguments

Brad King (4):
  FindBoost: Avoid leaking internal Boost_ROOT setting
  Help: Add 3.19 release note about CUDA support on QNX
  cmake-gui: Restore workaround for crash in file dialog
  CMake 3.19.0-rc3

Craig Scott (1):
  Help: Clarify variables specifying scripts to execute during packaging

Gusts Kaksis (1):
  Xcode: Inherit target library and framework search paths from project

Kyle Edwards (1):
  CMakePresets.json: Don't warn if no path argument is given

Marc Chevrier (1):
  cmake_path: remove new command from 3.19

Pavel Cernohorsky (1):
  FindPostgreSQL: support version 13

Peter Steneteg (1):
  Help: Clarify string(JSON) error handling

Tobias Ribizel (2):
  CTest: Add cuda-memcheck to Dart and CTest module
  Help: Add cuda-memcheck to CTest documentation

Tor Arne Vestbø (1):
  Apple: Update SDK architecture detection for tbd file version 4

janbernloehr (1):
  CUDA: Enable support on QNX