3.4.rst
CMake 3.4 Release Notes
***********************
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Changes made since CMake 3.3 include the following.
New Features
============
Generators
----------
* The :generator:`Visual Studio 14 2015` generator learned to select
a Windows 10 SDK based on the value of the :variable:`CMAKE_SYSTEM_VERSION`
variable and the SDKs available on the host.
* CMake learned rudimentary support for the Apple Swift language. When using
the :generator:`Xcode` generator with Xcode 6.1 or higher, one may enable
the ``Swift`` language with the :command:`enable_language` command or the
:command:`project` command (this is an error with other generators or when
Xcode is too old). Then one may list ``.swift`` source files in targets
for compilation.
Commands
--------
* The :command:`find_program` command learned a ``NAMES_PER_DIR``
option to consider all given ``NAMES`` in each directory before
moving on to the next directory.
* The :command:`get_filename_component` command learned a new ``BASE_DIR``
subcommand. This is used to specify a base directory when calculating an
absolute path from a relative path.
* The :command:`if` command learned a new ``TEST`` operator that evaluates
to true if a given test name has been defined by the :command:`add_test`
command. See policy :policy:`CMP0064`.
* The :command:`install(DIRECTORY)` command ``DESTINATION`` option learned to
support :manual:`generator expressions <cmake-generator-expressions(7)>`.
* The :command:`install(FILES)` command ``DESTINATION`` option learned to
support :manual:`generator expressions <cmake-generator-expressions(7)>`.
* The :command:`string` command learned a new ``APPEND`` subcommand.
Variables
---------
* The :ref:`Makefile Generators` and the :generator:`Ninja` generator
learned to add compiler launcher tools like distcc and ccache along
with the compiler for ``C`` and ``CXX`` languages. See the
:variable:`CMAKE_<LANG>_COMPILER_LAUNCHER` variable and
:prop_tgt:`<LANG>_COMPILER_LAUNCHER` target property for details.
* New :variable:`CMAKE_LINK_SEARCH_START_STATIC` and
:variable:`CMAKE_LINK_SEARCH_END_STATIC` variables were
introduced to initialize the
:prop_tgt:`LINK_SEARCH_START_STATIC` and
:prop_tgt:`LINK_SEARCH_END_STATIC` target properties,
respectively.
Properties
----------
* :ref:`Visual Studio Generators` learned to support additional
target properties to customize projects for NVIDIA Nsight
Tegra Visual Studio Edition:
* :prop_tgt:`ANDROID_ANT_ADDITIONAL_OPTIONS`
* :prop_tgt:`ANDROID_ARCH`
* :prop_tgt:`ANDROID_ASSETS_DIRECTORIES`
* :prop_tgt:`ANDROID_JAR_DEPENDENCIES`
* :prop_tgt:`ANDROID_JAR_DIRECTORIES`
* :prop_tgt:`ANDROID_JAVA_SOURCE_DIR`
* :prop_tgt:`ANDROID_NATIVE_LIB_DEPENDENCIES`
* :prop_tgt:`ANDROID_NATIVE_LIB_DIRECTORIES`
* :prop_tgt:`ANDROID_PROCESS_MAX`
* :prop_tgt:`ANDROID_PROGUARD`
* :prop_tgt:`ANDROID_PROGUARD_CONFIG_PATH`
* :prop_tgt:`ANDROID_SECURE_PROPS_PATH`
* :prop_tgt:`ANDROID_SKIP_ANT_STEP`
* :prop_tgt:`ANDROID_STL_TYPE`
* The :prop_tgt:`ARCHIVE_OUTPUT_DIRECTORY`,
:prop_tgt:`LIBRARY_OUTPUT_DIRECTORY`, and
:prop_tgt:`RUNTIME_OUTPUT_DIRECTORY` target properties learned to
support :manual:`generator expressions <cmake-generator-expressions(7)>`.
* The :prop_tgt:`SOURCE_DIR` and :prop_tgt:`BINARY_DIR` target properties
were introduced to allow project code to query where a target is defined.
* The :prop_tgt:`OUTPUT_NAME` target property and its variants learned to
support :manual:`generator expressions <cmake-generator-expressions(7)>`.
* A :prop_gbl:`TARGET_MESSAGES` global property was added to tell the
:ref:`Makefile Generators` whether to generate commands to print output
after each target is completed.
* On Windows with MS-compatible tools, CMake learned to optionally
generate a module definition (``.def``) file for ``SHARED`` libraries.
See the :prop_tgt:`WINDOWS_EXPORT_ALL_SYMBOLS` target property.
Modules
-------
* The :module:`ExternalProject` module :command:`ExternalProject_Add`
function ``GIT_SUBMODULES`` option now also limits the set of
submodules that are initialized in addition to the prior behavior
of limiting the set of submodules that are updated.
* The :module:`ExternalProject` module learned new ``USES_TERMINAL``
arguments for giving steps exclusive terminal access. This is
useful with the :generator:`Ninja` generator to monitor CMake
superbuild progress and prevent CPU oversubscription.
* The :module:`FindBISON` module ``BISON_TARGET`` macro learned a
new ``DEFINES_FILE`` option to specify a custom output header
to be generated.
* The :module:`FindHDF5` module learend a new ``HDF5_PREFER_PARALLEL``
option allowing users to specify that a parallel HDF5 tool is
preferred if both are available.
* The :module:`FindIce` module now provides imported targets.
* The :module:`FindJava` module learned to optionally find
the ``idlj`` and ``jarsigner`` tools.
* The :module:`FindOpenSSL` module now provides imported targets.
* The :module:`FindOpenSSL` module learned a new ``OPENSSL_USE_STATIC_LIBS``
option to search only for static libraries.
* The :module:`FindPkgConfig` learned a new :command:`pkg_get_variable`
command which may be used to query for arbitrary variables from a package
(such as for related tools or data and plugin install paths).
* The :module:`FindProtobuf` module gained a new
:command:`protobuf_generate_python` function to generate python
sources from ``.proto`` files.
* The :module:`FindTIFF` module learned to search separately for
debug and release variants.
* The :module:`FindwxWidgets` module learned to support version requests.
* The :module:`FindXercesC` module learned to search separately for
debug and release variants.
* The :module:`FindZLIB` module learned to search separately for
debug and release variants.
* The :module:`GNUInstallDirs` module learned special default values
for certain installation prefixes according to the `GNU Coding
Standards`_ and the `Filesystem Hierarchy Standard`_.
* The :module:`UseJava` module ``add_jar`` function learned
to support response files (e.g. ``@srcs.txt``) for source
specification.
* The :module:`UseJava` module ``install_jar`` function learned
new ``DESTINATION`` and ``COMPONENT`` options to specify
the corresponding :command:`install` command options.
* The :module:`UseJava` module gained a new ``create_javah``
function to create C headers from Java classes.
.. _`GNU Coding Standards`: https://www.gnu.org/prep/standards/html_node/Directory-Variables.html
.. _`Filesystem Hierarchy Standard`: https://refspecs.linuxfoundation.org/FHS_3.0/fhs/index.html
Generator Expressions
---------------------
* A new ``$<SHELL_PATH:...>``
:manual:`generator expression <cmake-generator-expressions(7)>`
has been added.
CTest
-----
* CTest learned to optionally measure the CPU load during parallel
testing and avoid starting tests that may cause the load to exceed
a given threshold. See the :manual:`ctest(1)` command ``--test-load``
option, the ``TestLoad`` setting of the :ref:`CTest Test Step`,
the :variable:`CTEST_TEST_LOAD` variable, and the ``TEST_LOAD``
option of the :command:`ctest_test` command.
* :manual:`ctest(1)` learned options
``--test-output-size-passed`` and ``--test-output-size-failed``
to customize the limit on test output size submitted when
running as a :ref:`Dashboard Client`.
CPack
-----
* The :cpack_gen:`CPack DEB Generator` learned to set package dependencies
per component. See variables:
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_BREAKS`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_CONFLICTS`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_ENHANCES`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_PREDEPENDS`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_PROVIDES`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_RECOMMENDS`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_REPLACES`
* :variable:`CPACK_DEBIAN_<COMPONENT>_PACKAGE_SUGGESTS`
* The :module:`CPack` module learned to package empty directories.
* The :module:`CPack` module gained a new setting, ``CPACK_VERBATIM_VARIABLES``,
which can be used to ensure the cpack program receives the settings' values
exactly as they were set, even if they contain CMake-special characters.
For compatibility, it's off by default.
Other
-----
* The :manual:`Compile Features <cmake-compile-features(7)>` functionality
is now aware of features supported by GNU C compilers on Windows.
* CMake learned to honor ``*.manifest`` source files with MSVC tools.
Manifest files named as sources of ``.exe`` and ``.dll`` targets
will be merged with linker-generated manifests and embedded in the
binary.
* The Concurrent Fortran 77 compiler is now supported.
Its :variable:`compiler id <CMAKE_<LANG>_COMPILER_ID>` is ``CCur``.
* :manual:`cmake(1)` gained a new ``--trace-expand`` command line option
that is like ``--trace`` but expands variable references in the output.
Deprecated and Removed Features
===============================
* The :module:`CMakeExpandImportedTargets` module is now documented
as deprecated. See module documentation for an explanation.
* The :variable:`CMAKE_USE_RELATIVE_PATHS` variable no longer has any
effect. Previously it was partially implemented and unreliable.
Other Changes
=============
* The :module:`CheckFunctionExists`, :module:`CheckLibraryExists`,
:module:`CheckSymbolExists`, and :module:`FindThreads` modules learned to
work in environments where only CXX is enabled.
* The :cpack_gen:`CPack DEB Generator` now correctly excludes symlinks
during package checksum calculation.
* The :cpack_gen:`CPack DEB Generator` no longer uses fakeroot and
system tar program for packaging.
* The :module:`CPack` module no longer mangles settings with CMake-special
characters when they're used as defaults for other settings. The macro
``cpack_set_if_not_set``, which was responsible for this, is now deprecated.
* CMake no longer links executables with flags to export symbols
unless the :prop_tgt:`ENABLE_EXPORTS` target property is set.
See policy :policy:`CMP0065`.
* The ``SONAME`` field is no longer set for ``MODULE`` libraries
created with the :command:`add_library` command. ``MODULE``
libraries are meant for explicit dynamic loading at runtime.
They cannot be linked so ``SONAME`` is not useful.
* The internal :variable:`CMAKE_<LANG>_COMPILE_OBJECT` rule variable now
substitutes compiler include flags in a separate ``<INCLUDES>`` placeholder
instead of the main ``<FLAGS>`` placeholder.