CMake 3.30 Release Notes
************************

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Changes made since CMake 3.29 include the following.

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

Presets
-------

* :manual:`cmake-presets(7)` files now support schema version ``9``.
  ``include`` fields now expand all macros except ``$env{}`` and
  preset-specific macros, i.e., those derived from the fields
  inside a preset's definition.

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

* The :manual:`cmake-file-api(7)` "cmakeFiles" version 1 object's ``version``
  field has been updated to 1.1.  It gained a ``globsDependent`` field to
  report :command:`file(GLOB)` calls using ``CONFIGURE_DEPENDS``.

Generators
----------

* :ref:`Visual Studio Generators` now add ``UseDebugLibraries`` indicators to
  ``.vcxproj`` files to denote which configurations are debug configurations.
  See policy :policy:`CMP0162`.

Languages
---------

* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
  now implements support for the ``cxx_std_26`` and ``cuda_std_26``
  meta-features to indicate that the compiler mode must be at least C++26.
  These meta-features were first documented by CMake 3.25, but were not fully
  implemented.

Commands
--------

* The :command:`add_library` command, on platforms that do not support shared
  libraries, now rejects creation of shared libraries instead of automatically
  converting them to static libraries.  See policy :policy:`CMP0164`.

* The :command:`enable_language` command now fails with an error
  if it is called before the first :command:`project` call.
  See policy :policy:`CMP0165`.

* The :command:`file(DOWNLOAD)` and :command:`file(UPLOAD)` commands
  gained a ``TLS_VERSION <min>`` option to specify the minimum TLS
  version for connections to ``https://`` URLs.

Variables
---------

* The :variable:`CMAKE_<LANG>_STANDARD_LATEST` variable was added to
  describe the latest ``<LANG>`` language standard CMake supports for
  the selected compiler.

* The :envvar:`CMAKE_TLS_VERIFY` environment variable was added as a fallback
  to the existing :variable:`CMAKE_TLS_VERIFY` variable.  It specifies
  whether to verify the server certificate for ``https://`` URLs by default.

* The :variable:`CMAKE_TLS_VERSION` variable and :envvar:`CMAKE_TLS_VERSION`
  environment variable were added to specify a default minimum TLS version
  for connections to ``https://`` URLs by the :command:`file(DOWNLOAD)`
  and :command:`file(UPLOAD)` commands.

* The :variable:`CMAKE_VS_USE_DEBUG_LIBRARIES` variable and corresponding
  :prop_tgt:`VS_USE_DEBUG_LIBRARIES` target property were added to explicitly
  control ``UseDebugLibraries`` indicators in ``.vcxproj`` files.

Properties
----------

* The :prop_sf:`GENERATED` source file property is now visible in all
  directories.  See policy :policy:`CMP0163`.  Policy :policy:`CMP0118`'s
  documentation has been revised to describe its actual effects.

* The :prop_gbl:`PROPAGATE_TOP_LEVEL_INCLUDES_TO_TRY_COMPILE` global property
  can be used to propagate :variable:`CMAKE_PROJECT_TOP_LEVEL_INCLUDES` into
  :command:`try_compile` calls that use the
  :ref:`whole-project signature <Try Compiling Whole Projects>`.
  This is primarily intended as a way for dependency providers to be enabled
  in such :command:`try_compile` calls.

* A :prop_tgt:`VS_FILTER_PROPS` target property was added to tell
  :ref:`Visual Studio Generators` to use a custom MSBuild filter
  ``.props`` file.

Modules
-------

* The :module:`ExternalProject` module's :command:`ExternalProject_Add`
  command gained a ``TLS_VERSION <min>`` option, and support for the
  :variable:`CMAKE_TLS_VERSION` variable and :envvar:`CMAKE_TLS_VERSION`
  environment variable, to specify the minimum TLS version for connections
  to ``https://`` URLs.

* The :module:`FindBacktrace` module now provides an imported target.

* The :module:`FindBLAS` and :module:`FindLAPACK` modules gained
  support for ``libblastrampoline``.

* The :module:`FindCUDAToolkit` module now provides a target for
  ``libnvfatbin`` and ``libnvfatbin_static``, if found.

* The :module:`FindCUDAToolkit` module now searches the
  :variable:`CMAKE_CUDA_COMPILER <CMAKE_<LANG>_COMPILER>`
  variable and the :envvar:`CUDACXX` environment variable
  even when the ``CUDA`` language isn't enabled.

* The :module:`FindOpenMP` module gained an ``OpenMP_RUNTIME_MSVC``
  option to control the OpenMP runtime used with MSVC.

* The :module:`FindPython` and :module:`FindPython3` modules gained
  support for the free threaded Python version.

* The :module:`FindPython`, :module:`FindPython2`, and :module:`FindPython3`
  modules, on Windows, now offer better support for the Python debug variant:

  * new variables:

    * ``Python_EXECUTABLE_DEBUG``
    * ``Python_INTERPRETER``
    * ``Python_DEBUG_POSTFIX``

  * new targets:

    * ``Python::InterpreterDebug``
    * ``Python::InterpreterMultiConfig``

  The ``python_add_library()`` command now manages the
  :prop_tgt:`DEBUG_POSTFIX` target property based on the value
  of the ``Python_DEBUG_POSTFIX`` variable.

Generator Expressions
---------------------

* The :genex:`<LANG>_COMPILER_FRONTEND_VARIANT <C_COMPILER_FRONTEND_VARIANT>`
  family of generator expressions were added to access the value of the
  associated :variable:`CMAKE_<LANG>_COMPILER_FRONTEND_VARIANT` variables.

* Link features, as used with the :genex:`LINK_LIBRARY` generator expression,
  gained the ability to have attributes that describe their behavior by
  specifying the :variable:`CMAKE_LINK_LIBRARY_<FEATURE>_ATTRIBUTES` or
  :variable:`CMAKE_<LANG>_LINK_LIBRARY_<FEATURE>_ATTRIBUTES` variables.

* The :genex:`QUOTE` generator expression was added to evaluate to ``"``.

* The :genex:`TARGET_PROPERTY` generator expression learned to evaluate
  :ref:`custom transitive properties <Custom Transitive Properties>`
  defined by new :prop_tgt:`TRANSITIVE_COMPILE_PROPERTIES` and
  :prop_tgt:`TRANSITIVE_LINK_PROPERTIES` target properties.

* The :genex:`TARGET_PROPERTY` generator expression now evaluates target
  properties :prop_tgt:`INTERFACE_LINK_OPTIONS`,
  :prop_tgt:`INTERFACE_LINK_DIRECTORIES`, and
  :prop_tgt:`INTERFACE_LINK_DEPENDS` correctly by following private
  dependencies of static libraries.  See policy :policy:`CMP0166`.

CTest
-----

* The :command:`ctest_submit` command and :option:`ctest -T Submit <ctest -T>`
  step gained ``TLSVersion`` and ``TLSVerify`` options to control negotiation
  with ``https://`` URLs.  See the :variable:`CTEST_TLS_VERSION` and
  :variable:`CTEST_TLS_VERIFY` variables.

CPack
-----

* The :cpack_gen:`CPack Inno Setup Generator` is now available
  on non-Windows hosts.

* The :cpack_gen:`CPack NuGet Generator` gained the
  :variable:`CPACK_NUGET_PACKAGE_README`,
  :variable:`CPACK_NUGET_PACKAGE_REPOSITORY_URL`,
  :variable:`CPACK_NUGET_PACKAGE_REPOSITORY_TYPE`,
  :variable:`CPACK_NUGET_PACKAGE_REPOSITORY_BRANCH`, and
  :variable:`CPACK_NUGET_PACKAGE_REPOSITORY_COMMIT` variables.

* The :cpack_gen:`CPack NuGet Generator` can now generate dependency groups
  for framework-specific dependencies. The :variable:`CPACK_NUGET_PACKAGE_TFMS`
  variable was added to specify a list of target framework monikers (TFMs)
  for which groups should be generated.

* The :cpack_gen:`CPack WIX Generator` gained support for WiX Toolset v4.
  See the :variable:`CPACK_WIX_VERSION` variable.

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

* The :module:`FindBoost` module has been removed by policy :policy:`CMP0167`.
  Port projects to upstream Boost's ``BoostConfig.cmake`` package
  configuration file, for which ``find_package(Boost)`` now searches.

* Calling :command:`FetchContent_Populate` with just the name of a
  dependency is now deprecated. Projects should call
  :command:`FetchContent_MakeAvailable` instead. See policy :policy:`CMP0169`.
  Calling :command:`FetchContent_Populate` with full population details
  rather than just a dependency name remains fully supported.

* The :generator:`Visual Studio 9 2008` generator has been removed.

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

* The precompiled Windows ``.msi`` installers provided on
  `cmake.org <https://cmake.org/download/>`_, when performing a fresh
  installation, now modify the system-wide ``PATH`` by default.
  When replacing an existing installation of 3.30 or later, the ``PATH``
  modification preference is preserved by default.

* The official ``.zip`` source archive provided on
  `cmake.org <https://cmake.org/download/>`_ now uses LF newlines,
  instead of CRLF newlines, for consistency with modern conventions.

* The durations printed after "Configuring done" and "Generating done"
  messages now reflect time spent in generator-specific steps, and
  in a code model evaluation step at the beginning of generation that
  was not previously captured.  Printed durations may appear longer
  than in previous versions of CMake, but are more accurate.

* :module:`FetchContent` now prefers to populate content directly rather
  than using a separate sub-build. This may significantly improve configure
  times on some systems (Windows especially, but also on macOS when using
  the Xcode generator). :option:`cmake --fresh` also forces the download,
  update, and patch steps of directly populated dependencies to be re-executed.
  Policy :policy:`CMP0168` provides backward compatibility for those projects
  that still rely on using a sub-build for content population.

* When :variable:`FETCHCONTENT_FULLY_DISCONNECTED` is set to true,
  :command:`FetchContent_MakeAvailable` and the single-argument form of
  :command:`FetchContent_Populate` require that the dependency's source
  directory has already been populated. CMake 3.29 and earlier did not
  check this requirement, but it is now enforced, subject to policy
  :policy:`CMP0170`.

Updates
=======

Changes made since CMake 3.30.0 include the following.

3.30.1, 3.30.2
--------------

* These versions made no changes to documented features or interfaces.
  Some implementation updates were made to support ecosystem changes
  and/or fix regressions.

3.30.3
------

* The :command:`project(<PROJECT-NAME>)` command now sets
  :variable:`<PROJECT-NAME>_SOURCE_DIR`, :variable:`<PROJECT-NAME>_BINARY_DIR`,
  and :variable:`<PROJECT-NAME>_IS_TOP_LEVEL` as normal variables in addition
  to setting them as cache entries.  This is needed to preserve support for
  some :module:`FetchContent` use cases under policy :policy:`CMP0169`'s
  NEW behavior.

* The :module:`FindPython` and :module:`FindPython3` modules now define,
  respectively, the ``Python_DEFINITIONS`` and  ``Python3_DEFINITIONS``
  variables on Windows to support development with the free threaded
  version of Python.  The :prop_tgt:`INTERFACE_COMPILE_DEFINITIONS` target
  property is also defined for the various targets provided by these modules.

3.30.4
------

* The :command:`project(<PROJECT-NAME>)` command now sets
  :variable:`<PROJECT-NAME>_SOURCE_DIR`, :variable:`<PROJECT-NAME>_BINARY_DIR`,
  and :variable:`<PROJECT-NAME>_IS_TOP_LEVEL` as normal variables only if they
  are already set as cache or non-cache variables when :command:`project` is
  invoked.  Cache entries by the same names are always set as before.
  This refines 3.30.3's behavior change to restore behavior of nested
  directories that call :command:`project` with the same project name,
  but the implementation in this release is flawed (this release note has
  been retoractively updated).  It can result in different behavior between
  the first and subsequent runs.  Do not use CMake 3.30.4 if your project
  contains nested calls to :command:`project` with the same project name
  and you use these variables.

3.30.5
------

* The :command:`project(<PROJECT-NAME>)` command now sets
  :variable:`<PROJECT-NAME>_SOURCE_DIR`, :variable:`<PROJECT-NAME>_BINARY_DIR`,
  and :variable:`<PROJECT-NAME>_IS_TOP_LEVEL` as non-cache variables only if
  they are already set as non-cache variables when :command:`project` is
  invoked.  Cache entries by the same names are always set as before.
  This refines 3.30.3's behavior change to restore behavior of nested
  directories that call :command:`project` with the same project name,
  and it addresses the bug in the implementation introduced in 3.30.4.
