Help/release/3.8.rst

CMake 3.8 Release Notes
***********************

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Changes made since CMake 3.7 include the following.

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

Languages
---------

C#
^^

* CMake learned to support ``CSharp`` (C#) as a first-class language that
  can be enabled via the :command:`project` and :command:`enable_language`
  commands.  It is currently supported by the :ref:`Visual Studio Generators`
  for VS 2010 and above.

  C# assemblies and programs can be added just like common C++ targets using
  the :command:`add_library` and :command:`add_executable` commands.
  References between C# targets in the same source tree may be specified by
  :command:`target_link_libraries` like for C++.  References to system or
  3rd-party assemblies may be specified by the target properties
  :prop_tgt:`VS_DOTNET_REFERENCE_<refname>` and
  :prop_tgt:`VS_DOTNET_REFERENCES`.

* More fine tuning of C# targets may be done using target and source
  file properties.  Specifically the target properties related to
  Visual Studio (``VS_*``) are worth a look (for setting toolset
  versions, root namespaces, assembly icons, ...).

CUDA
^^^^

* CMake learned to support ``CUDA`` as a first-class language that can be
  enabled via the :command:`project` and :command:`enable_language` commands.

* ``CUDA`` is currently supported by the :ref:`Makefile Generators`
  and the :generator:`Ninja` generator on Linux, macOS, and Windows.
  Support for the Visual Studio IDE is under development but not
  included in this release.

* The NVIDIA CUDA Toolkit compiler (``nvcc``) is supported.

C & C++
^^^^^^^

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  now offers meta-features that request compiler modes for specific language
  standard levels (e.g. ``cxx_std_11``).  See
  :prop_gbl:`CMAKE_C_KNOWN_FEATURES` and :prop_gbl:`CMAKE_CXX_KNOWN_FEATURES`.

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  is now aware of C++ 17.  No specific features are yet enumerated besides
  the ``cxx_std_17`` meta-feature.

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  is now aware of the availability of C99 in gcc since version 3.4.

Platforms
---------

* A new minimal platform file for ``Fuchsia`` was added.

Generators
----------

* The :generator:`CodeBlocks` extra generator may now be used to
  generate with :generator:`NMake Makefiles JOM`.

* The :ref:`Visual Studio Generators` for VS 2013 and above learned to
  support a ``host=x64`` option in the :variable:`CMAKE_GENERATOR_TOOLSET`
  value (e.g.  via the :manual:`cmake(1)` ``-T`` option) to request use
  of a VS 64-bit toolchain on 64-bit hosts.

* The :ref:`Visual Studio Generators` learned to treat files passed to
  :command:`target_link_libraries` whose names end in ``.targets``
  as MSBuild "targets" files to be imported into generated project files.

Commands
--------

* The :command:`add_custom_command` and :command:`add_custom_target` commands
  learned the option ``COMMAND_EXPAND_LISTS`` which causes lists in the
  ``COMMAND`` argument to be expanded, including lists created by generator
  expressions.

* The :command:`execute_process` command gained an ``ENCODING`` option to
  specify on Windows which encoding is used for output from child process.

* The :command:`math(EXPR)` command gained support for unary
  ``+`` and ``-`` operators.

* The :command:`source_group` command gained ``TREE`` and ``PREFIX``
  options to add groups following source tree directory structure.

* The :command:`string(TIMESTAMP)` command learned to treat ``%%``
  as a way to encode plain ``%``.

* The :command:`string(TIMESTAMP)` command will now honor the
  ``SOURCE_DATE_EPOCH`` environment variable and use its value
  instead of the current time.

* The :command:`try_compile` command source file signature gained new options
  to specify the language standard to use in the generated test project.

* The :command:`try_compile` command source file signature now honors
  language standard variables like :variable:`CMAKE_CXX_STANDARD`.
  See policy :policy:`CMP0067`.

Variables
---------

* A :variable:`CMAKE_CODELITE_USE_TARGETS` variable was added to tell the
  :generator:`CodeLite` extra generator to change the generated project
  to have target-centric organization.
  The ``build``, ``rebuild``, and ``clean`` operations within ``CodeLite``
  then work on a selected target rather than the whole workspace.
  (Note that the :generator:`Ninja` clean operation on a target
  includes its dependencies, though.)

* The :variable:`CMAKE_SUBLIME_TEXT_2_ENV_SETTINGS` variable was added to
  tell the :generator:`Sublime Text 2` extra generator to place specified
  environment variables in the generated ``.sublime-project``.

* The :variable:`CMAKE_SUBLIME_TEXT_2_EXCLUDE_BUILD_TREE` variable was added
  to tell the :generator:`Sublime Text 2` extra generator whether to exclude
  the build tree from the ``.sublime-project`` when it is inside the source
  tree.

* A :variable:`CMAKE_VS_INCLUDE_PACKAGE_TO_DEFAULT_BUILD` variable was
  added to tell :ref:`Visual Studio Generators` for VS 2010 and above
  to include the ``PACKAGE`` target in the default build, similar to
  the existing :variable:`CMAKE_VS_INCLUDE_INSTALL_TO_DEFAULT_BUILD`
  variable for the ``INSTALL`` target.

Properties
----------

* A :prop_tgt:`BUILD_RPATH` target property and corresponding
  :variable:`CMAKE_BUILD_RPATH` variable were added to support custom
  ``RPATH`` locations to be added to binaries in the build tree.

* The :prop_sf:`COMPILE_FLAGS` source file property learned to support
  :manual:`generator expressions <cmake-generator-expressions(7)>`.

* The :prop_tgt:`FRAMEWORK` target property may now also be applied to
  static libraries on Apple targets.  It will result in a proper
  Framework but with a static library inside.

* :ref:`Imported <Imported Targets>` :ref:`Interface Libraries` learned new
  :prop_tgt:`IMPORTED_LIBNAME` and :prop_tgt:`IMPORTED_LIBNAME_<CONFIG>`
  target properties to specify a link library name since interface libraries
  do not build their own library files.

* A :prop_tgt:`<LANG>_CPPLINT` target property and supporting
  :variable:`CMAKE_<LANG>_CPPLINT` variable were introduced to tell
  the :ref:`Makefile Generators` and the :generator:`Ninja` generator to
  run the ``cpplint`` style checker along with the compiler for ``C`` and
  ``CXX`` languages.

* A :prop_tgt:`MANUALLY_ADDED_DEPENDENCIES` target property has been added.
  It provides a read-only list of dependencies that have been added with
  the :command:`add_dependencies` command.

* The :prop_tgt:`MAP_IMPORTED_CONFIG_<CONFIG>` target property learned
  to interpret empty list elements as referring to the configuration-less
  imported location specified by :prop_tgt:`IMPORTED_LOCATION`.

* The :prop_tgt:`NO_SYSTEM_FROM_IMPORTED` target property is now supported
  on :ref:`Imported <Imported Targets>` :ref:`Interface Libraries`.

* New source file properties :prop_sf:`SKIP_AUTOMOC`, :prop_sf:`SKIP_AUTOUIC`,
  :prop_sf:`SKIP_AUTORCC`, and :prop_sf:`SKIP_AUTOGEN` were added to allow
  source files to be excluded from processing by :prop_tgt:`AUTOMOC`,
  :prop_tgt:`AUTOUIC`, and :prop_tgt:`AUTORCC` target properties.

* A :prop_sf:`VS_COPY_TO_OUT_DIR` source file property was added to
  tell :ref:`Visual Studio Generators` for VS 2010 and above whether
  or not a file should e copied to the output directory.

* A :prop_tgt:`VS_DEBUGGER_WORKING_DIRECTORY` target property was added
  to tell :ref:`Visual Studio Generators` for VS 2010 and above what
  debugger working directory should be set for the target.

* A :prop_tgt:`VS_DOTNET_REFERENCES_COPY_LOCAL` target property was added
  to specify whether to copy referenced assemblies to the output directory.

* A :prop_tgt:`VS_DOTNET_REFERENCE_<refname>` target property was added
  to tell :ref:`Visual Studio Generators` for VS 2010 and above to add
  a .NET reference with a given hint path.

* A :prop_sf:`VS_INCLUDE_IN_VSIX` source file property was added to
  tell :ref:`Visual Studio Generators` for VS 2010 and above whether
  to include the file in a Visual Studio extension package.

* A :prop_sf:`VS_RESOURCE_GENERATOR` source file property was added to
  give :ref:`Visual Studio Generators` for VS 2010 and above a setting
  for the resource generator (``C#`` only).

* A :prop_tgt:`VS_USER_PROPS` target property was added to tell
  :ref:`Visual Studio Generators` for VS 2010 and above to use a
  custom MSBuild user ``.props`` file.

* A :prop_gbl:`XCODE_EMIT_EFFECTIVE_PLATFORM_NAME` global property was
  added to tell the :generator:`Xcode` generator whether to emit the
  ``EFFECTIVE_PLATFORM_NAME`` variable.  This is useful when building
  with multiple SDKs like ``macosx`` and ``iphoneos`` in parallel.

* New :prop_tgt:`XCODE_PRODUCT_TYPE` and :prop_tgt:`XCODE_EXPLICIT_FILE_TYPE`
  target properties were created to tell the :generator:`Xcode` generator
  to use custom values of the corresponding attributes for a target in the
  generated Xcode project.

Modules
-------

* A :module:`CSharpUtilities` module was added to aid parameterization of
  Visual Studio C# targets.  It provides functions to allow automated
  setting of source file properties to support Windows Forms, WPF/XAML or
  other technologies as needed.

* The :module:`ExternalData` module learned to support multiple
  content links for one data file using different hashes, e.g.
  ``img.png.sha256`` and ``img.png.sha1``.  This allows objects
  to be fetched from sources indexed by different hash algorithms.

* The :module:`ExternalProject` module gained the ``GIT_PROGRESS`` option to
  force Git to show progress when cloning repositories.

* The :module:`ExternalProject` module gained a ``GIT_CONFIG`` option
  to pass ``--config`` options to Git when cloning repositories.

* The :module:`FeatureSummary` module :command:`feature_summary` command now
  accepts a new ``QUIET_ON_EMPTY`` option that suppresses the output when
  the list of packages that belong to the selected category is empty.

* The :module:`FeatureSummary` module :command:`add_feature_info` command
  now accepts lists of dependencies for deciding whether a feature is enabled
  or not.

* The package types accepted by the :module:`FeatureSummary` module can now
  be tweaked by changing the :variable:`FeatureSummary_PKG_TYPES`,
  :variable:`FeatureSummary_REQUIRED_PKG_TYPES` and
  :variable:`FeatureSummary_DEFAULT_PKG_TYPE` global properties.

* The :module:`FindOpenGL` module now provides imported targets
  ``OpenGL::GL`` and ``OpenGL::GLU`` when the libraries are found.

* The :module:`UseSWIG` module gained a ``swig_add_library`` command
  to give more flexibility over the old ``swig_add_module`` command.

* The :module:`UseSWIG` module ``swig_add_source_to_module`` command
  learned a new ``SWIG_OUTFILE_DIR`` option to control the output
  file location (``swig -o``).

* The :module:`WriteCompilerDetectionHeader` module gained the
  ``ALLOW_UNKNOWN_COMPILERS`` and ``ALLOW_UNKNOWN_COMPILER_VERSIONS`` options
  that allow creation of headers that will work also with unknown or old
  compilers by simply assuming they do not support any of the requested
  features.

CTest
-----

* The :command:`ctest_memcheck` command gained a ``DEFECT_COUNT <var>``
  option to capture the number of memory defects detected.

* The :command:`ctest_memcheck` command learned to read the location of
  suppressions files for sanitizers from the
  :variable:`CTEST_MEMORYCHECK_SUPPRESSIONS_FILE` variable.

* The :command:`ctest_memcheck` command learned to support ``LeakSanitizer``
  independently from ``AddressSanitizer``.

* The :command:`ctest_update` command ``CDASH_UPLOAD`` signature was taught
  to honor the ``RETRY_COUNT``, ``RETRY_DELAY``, and ``QUIET`` options.

CPack
-----

* The :module:`CPackIFWConfigureFile` module was added to define a new
  :command:`cpack_ifw_configure_file` command to configure file templates
  prepared in QtIFW/SDK/Creator style.

* The :module:`CPackIFW` module :command:`cpack_ifw_configure_component` and
  :command:`cpack_ifw_configure_component_group` commands gained a new
  ``DEFAULT``, ``VIRTUAL``, ``FORCED_INSTALLATION``, ``REQUIRES_ADMIN_RIGHTS``,
  ``DISPLAY_NAME``, ``UPDATE_TEXT``, ``DESCRIPTION``, ``RELEASE_DATE``,
  ``AUTO_DEPEND_ON`` and ``TRANSLATIONS`` options to more specific
  configuration.

* The :module:`CPackIFW` module :command:`cpack_ifw_configure_component`
  command gained a new ``DEPENDENCIES`` alias for ``DEPENDS`` option.

* The :module:`CPackIFW` module :command:`cpack_ifw_configure_component_group`
  command gained a new ``DEPENDS`` option. The ``DEPENDENCIES`` alias also
  added.

* The :module:`CPackIFW` module :command:`cpack_ifw_configure_component` and
  :command:`cpack_ifw_configure_component_group` commands ``PRIORITY``
  option now is deprecated and will be removed in a future version of CMake.
  Please use new ``SORTING_PRIORITY`` option instead.

* The :cpack_gen:`CPack IFW Generator` gained new
  :variable:`CPACK_IFW_PACKAGE_WATERMARK`,
  :variable:`CPACK_IFW_PACKAGE_BANNER`,
  :variable:`CPACK_IFW_PACKAGE_BACKGROUND`,
  :variable:`CPACK_IFW_PACKAGE_WIZARD_STYLE`,
  :variable:`CPACK_IFW_PACKAGE_WIZARD_DEFAULT_WIDTH`,
  :variable:`CPACK_IFW_PACKAGE_WIZARD_DEFAULT_HEIGHT`, and
  :variable:`CPACK_IFW_PACKAGE_TITLE_COLOR`
  variables to customize a QtIFW installer look.

* The :cpack_gen:`CPack productbuild Generator` gained options to sign packages.
  See the variables :variable:`CPACK_PRODUCTBUILD_IDENTITY_NAME`,
  :variable:`CPACK_PRODUCTBUILD_KEYCHAIN_PATH`,
  :variable:`CPACK_PKGBUILD_IDENTITY_NAME`, and
  :variable:`CPACK_PKGBUILD_KEYCHAIN_PATH`.

* The :cpack_gen:`CPack RPM Generator` learned to omit tags that are not
  supported by provided ``rpmbuild`` tool. If unsupported tags are set they
  are ignored and a developer warning is printed out.

* The :cpack_gen:`CPack RPM Generator` learned to generate main component
  package which forces generation of a rpm for defined component without
  component suffix in filename and package name.
  See :variable:`CPACK_RPM_MAIN_COMPONENT` variable.

* The :cpack_gen:`CPack RPM Generator` learned to generate a single
  ``debuginfo`` package on demand even if components packaging is used.
  See :variable:`CPACK_RPM_DEBUGINFO_SINGLE_PACKAGE` variable.

* The :cpack_gen:`CPack RPM Generator` learned to support
  multiple directives per file when using
  :variable:`CPACK_RPM_USER_FILELIST` variable.

Other
-----

* CMake functionality using cryptographic hashes now supports SHA-3 algorithms.

* A new generator expression ``$<IF:cond,true-value,false-value>`` was added.
  It resolves to the true-value if the condition is ``1`` and resolves to
  the false-value if the condition is ``0``.

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

* The :module:`FeatureSummary` module commands :command:`set_package_info`,
  :command:`set_feature_info`, :command:`print_enabled_features`, and
  :command:`print_disabled_features` are now deprecated.

* The :module:`UseSWIG` module ``swig_add_module`` command is now
  deprecated in favor of ``swig_add_library``.

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

* If a command specified by the :prop_tgt:`<LANG>_CLANG_TIDY` target property
  returns non-zero at build time this is now treated as an error instead of
  silently ignored.

* The :command:`ctest_memcheck` command no longer automatically adds
  ``leak_check=1`` to the options used by ``AddressSanitizer``. The default
  behavior of ``AddressSanitizer`` is to run `LeakSanitizer` to check leaks
  unless ``leak_check=0``.

* The :command:`ctest_memcheck` command was fixed to correctly append extra
  sanitizer options read from the
  :variable:`CTEST_MEMORYCHECK_SANITIZER_OPTIONS` variable to the environment
  variables used internally by the sanitizers.

* The :module:`FeatureSummary` module :command:`set_package_properties`
  command no longer forces the package type to ``OPTIONAL`` when the type
  is not explicitly set.

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  is now aware of features supported by Intel C++ compilers versions 12.1
  through 17.0 on UNIX and Windows platforms.

* Calls to the :module:`FindPkgConfig` module :command:`pkg_check_modules`
  command following a successful call learned to re-evaluate the cached values
  for a given prefix after changes to the parameters to the command for that
  prefix.

* When using :prop_tgt:`AUTOMOC` or :prop_tgt:`AUTOUIC`, generated
  ``moc_*``, ``*.moc`` and ``ui_*`` are placed in the
  ``<CMAKE_CURRENT_BINARY_DIR>/<TARGETNAME>_autogen/include`` directory which
  is automatically added to the target's :prop_tgt:`INCLUDE_DIRECTORIES`.
  It is therefore not necessary anymore to have
  :variable:`CMAKE_CURRENT_BINARY_DIR` in the target's
  :prop_tgt:`INCLUDE_DIRECTORIES`.

* The :generator:`Sublime Text 2` generator no longer runs the native
  build command (e.g. ``ninja`` or ``make``) with verbose build output
  enabled.

* The :command:`try_compile` command source file signature now
  honors the :variable:`CMAKE_WARN_DEPRECATED` variable value
  in the generated test project.

* The :ref:`Visual Studio Generators` for VS 2010 and above now place
  per-source file flags after target-wide flags when they are classified
  as raw flags with no project file setting (``AdditionalOptions``).
  This behavior is more consistent with the ordering of flags produced
  by other generators, and allows flags on more-specific properties
  (per-source) to override those on more general ones (per-target).

* The precompiled Windows binary MSI package provided on ``cmake.org`` now
  records the installation directory in the Windows Registry under the key
  ``HKLM\Software\Kitware\CMake`` with a value named ``InstallDir``.