CMake/ChangeLog

From KitwarePublic
Jump to: navigation, search

CMake 3.0.0 Release Notes
*************************

Changes made since CMake 2.8.12.2 include the following.


Documentation Changes
=====================

* The CMake documentation has been converted to reStructuredText and
  now transforms via Sphinx (http://sphinx-doc.org) into man and html
  pages.  This allows the documentation to be properly indexed and to
  contain cross-references.

  Conversion from the old internal documentation format was done by an
  automatic process so some documents may still contain artifacts.
  They will be updated incrementally over time.

  A basic reStructuredText processor has been implemented to support
  "cmake --help-command" and similar command-line options.

* New manuals were added:

  * "cmake-buildsystem(7)"

  * "cmake-commands(7)", replacing "cmakecommands(1)" and
    "cmakecompat(1)"

  * "cmake-developer(7)"

  * "cmake-generator-expressions(7)"

  * "cmake-generators(7)"

  * "cmake-language(7)"

  * "cmake-modules(7)", replacing "cmakemodules(1)"

  * "cmake-packages(7)"

  * "cmake-policies(7)", replacing "cmakepolicies(1)"

  * "cmake-properties(7)", replacing "cmakeprops(1)"

  * "cmake-qt(7)"

  * "cmake-toolchains(7)"

  * "cmake-variables(7)", replacing "cmakevars(1)"

* Release notes for CMake 3.0.0 and above will now be included with
  the html documentation.


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


Syntax
------

* The CMake language has been extended with *Bracket Argument* and
  *Bracket Comment* syntax inspired by Lua long brackets:

     set(x [===[bracket argument]===] #[[bracket comment]])

  Content between equal-length open- and close-brackets is taken
  literally with no variable replacements.

  Warning: This syntax change could not be made in a fully
    compatible way. No policy is possible because syntax parsing
    occurs before any chance to set a policy.  Existing code using an
    unquoted argument that starts with an open bracket will be
    interpreted differently without any diagnostic.  Fortunately the
    syntax is obscure enough that this problem is unlikely in
    practice.


Generators
----------

* A new "CodeLite" extra generator is available for use with the
  Makefile or Ninja generators.

* A new "Kate" extra generator is available for use with the
  Makefile or Ninja generators.

* The "Ninja" generator learned to use "ninja" job pools when
  specified by a new "JOB_POOLS" global property.


Commands
--------

* The "add_library()" command learned a new "INTERFACE" library
  type. Interface libraries have no build rules but may have
  properties defining "usage requirements" and may be installed,
  exported, and imported.  This is useful to create header-only
  libraries that have concrete link dependencies on other libraries.

* The "export()" command learned a new "EXPORT" mode that retrieves
  the list of targets to export from an export set configured by the
  "install(TARGETS)" command "EXPORT" option.  This makes it easy to
  export from the build tree the same targets that are exported from
  the install tree.

* The "export()" command learned to work with multiple dependent
  export sets, thus allowing multiple packages to be built and
  exported from a single tree.  The feature requires CMake to wait
  until the generation step to write the output file.  This means one
  should not "include()" the generated targets file later during
  project configuration because it will not be available. Use *Alias
  Targets* instead.  See policy "CMP0024".

* The "install(FILES)" command learned to support "generator
  expressions" in the list of files.

* The "project()" command learned to set some version variables to
  values specified by the new "VERSION" option or to empty strings.
  See policy "CMP0048".

* The "string()" command learned a new "CONCAT" mode. It is
  particularly useful in combination with the new *Bracket Argument*
  syntax.

* The "unset()" command learned a "PARENT_SCOPE" option matching
  that of the "set()" command.

* The "include_external_msproject()" command learned to handle
  non-C++ projects like ".vbproj" or ".csproj".

* The "ctest_update()" command learned to update work trees managed
  by the Perforce (p4) version control tool.

* The "message()" command learned a "DEPRECATION" mode. Such
  messages are not issued by default, but may be issued as a warning
  if "CMAKE_WARN_DEPRECATED" is enabled, or as an error if
  "CMAKE_ERROR_DEPRECATED" is enabled.

* The "target_link_libraries()" command now allows repeated use of
  the "LINK_PUBLIC" and "LINK_PRIVATE" keywords.


Variables
---------

* Variable "CMAKE_FIND_NO_INSTALL_PREFIX" has been introduced to
  tell CMake not to add the value of "CMAKE_INSTALL_PREFIX" to the
  "CMAKE_SYSTEM_PREFIX_PATH" variable by default. This is useful when
  building a project that installs some of its own dependencies to
  avoid finding files it is about to replace.

* Variable "CMAKE_STAGING_PREFIX" was introduced for use when cross-
  compiling to specify an installation prefix on the host system that
  differs from a "CMAKE_INSTALL_PREFIX" value meant for the target
  system.

* Variable "CMAKE_SYSROOT" was introduced to specify the toolchain
  SDK installation prefix, typically for cross-compiling. This is used
  to pass a "--sysroot" option to the compiler and as a prefix
  searched by "find_*" commands.

* Variable "CMAKE_<LANG>_COMPILER_TARGET" was introduced for use
  when cross-compiling to specify the target platform in the
  *toolchain file* specified by the "CMAKE_TOOLCHAIN_FILE" variable.
  This is used to pass an option such as "--target=<triple>" to some
  cross- compiling compiler drivers.

* Variable "CMAKE_MAP_IMPORTED_CONFIG_<CONFIG>" has been introduced
  to optionally initialize the "MAP_IMPORTED_CONFIG_<CONFIG>" target
  property.


Properties
----------

* The "ADDITIONAL_MAKE_CLEAN_FILES" directory property learned to
  support "generator expressions".

* A new directory property "CMAKE_CONFIGURE_DEPENDS" was introduced
  to allow projects to specify additional files on which the
  configuration process depends.  CMake will re-run at build time when
  one of these files is modified. Previously this was only possible to
  achieve by specifying such files as the input to a
  "configure_file()" command.

* A new *AUTORCC* feature replaces the need to invoke
  "qt4_add_resources()" by allowing ".qrc" files to be listed as
  target sources.

* A new *AUTOUIC* feature replaces the need to invoke
  "qt4_wrap_ui()".

* Test properties learned to support "generator expressions". This
  is useful to specify per-configuration values for test properties
  like "REQUIRED_FILES" and "WORKING_DIRECTORY".

* A new "SKIP_RETURN_CODE" test property was introduced to tell
  "ctest(1)" to treat a particular test return code as if the test
  were not run.  This is useful for test drivers to report that
  certain test requirements were not available.

* New types of *Compatible Interface Properties* were introduced,
  namely the "COMPATIBLE_INTERFACE_NUMBER_MAX" and
  "COMPATIBLE_INTERFACE_NUMBER_MIN" for calculating numeric maximum
  and minimum values respectively.


Modules
-------

* The "CheckTypeSize" module "check_type_size" macro and the
  "CheckStructHasMember" module "check_struct_has_member" macro
  learned a new "LANGUAGE" option to optionally check C++ types.

* The "ExternalData" module learned to work with no URL templates if
  a local store is available.

* The "ExternalProject" function "ExternalProject_Add" learned a new
  "GIT_SUBMODULES" option to specify a subset of available submodules
  to checkout.

* A new "FindBacktrace" module has been added to support
  "find_package(Backtrace)" calls.

* A new "FindLua" module has been added to support
  "find_package(Lua)" calls.

* The "FindBoost" module learned a new "Boost_NAMESPACE" option to
  change the "boost" prefix on library names.

* The "FindBoost" module learned to control search for libraies with
  the "g" tag (for MS debug runtime) with a new
  "Boost_USE_DEBUG_RUNTIME" option.  It is "ON" by default to preserve
  existing behavior.

* The "FindJava" and "FindJNI" modules learned to use a "JAVA_HOME"
  CMake variable or environment variable, and then try
  "/usr/libexec/java_home" on OS X.

* The "UseJava" module "add_jar" function learned a new "MANIFEST"
  option to pass the "-m" option to "jar".

* A new "CMakeFindDependencyMacro" module was introduced with a
  "find_dependency" macro to find transitive dependencies in a
  "package configuration file".  Such dependencies are omitted by the
  listing of the "FeatureSummary" module.

* The "FindQt4" module learned to create *Imported Targets* for Qt
  executables.  This helps disambiguate when using multiple "Qt
  versions" in the same buildsystem.


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

* New "$<PLATFORM_ID>" and "$<PLATFORM_ID:...>" "generator
  expressions" have been added.

* The "$<CONFIG>" "generator expression" now has a variant which
  takes no argument.  This is equivalent to the "$<CONFIGURATION>"
  expression.

* New "$<UPPER_CASE:...>" and "$<LOWER_CASE:...>" "generator
  expressions" generator expressions have been added.

* A new "$<MAKE_C_IDENTIFIER:...>" "generator expression" has been
  added.


Other
-----

* The "cmake(1)" "-E" option learned a new "sleep" command.

* The "ccmake(1)" dialog learned to honor the "STRINGS" cache entry
  property to cycle through the enumerated list of possible values.

* The "cmake-gui(1)" dialog learned to remember window settings
  between sessions.

* The "cmake-gui(1)" dialog learned to remember the type of a cache
  entry for completion in the "Add Entry" dialog.


New Diagnostics
===============

* Directories named in the "INTERFACE_INCLUDE_DIRECTORIES" target
  property of imported targets linked conditionally by a "generator
  expression" were not checked for existence.  Now they are checked.
  See policy "CMP0027".

* Build target names must now match a validity pattern and may no
  longer conflict with CMake-defined targets.  See policy "CMP0037".

* Build targets that specify themselves as a link dependency were
  silently accepted but are now diagnosed.  See "CMP0038".

* The "target_link_libraries()" command used to silently ignore
  calls specifying as their first argument build targets created by
  "add_custom_target()" but now diagnoses this mistake. See policy
  "CMP0039".

* The "add_custom_command()" command used to silently ignore calls
  specifying the "TARGET" option with a non-existent target but now
  diagnoses this mistake.  See policy "CMP0040".

* Relative paths in the "INTERFACE_INCLUDE_DIRECTORIES" target
  property used to be silently accepted if they contained a "generator
  expression" but are now rejected.  See policy "CMP0041".

* The "get_target_property()" command learned to reject calls
  specifying a non-existent target.  See policy "CMP0045".

* The "add_dependencies()" command learned to reject calls
  specifying a dependency on a non-existent target. See policy
  "CMP0046".

* Link dependency analysis learned to assume names containing "::"
  refer to *Alias Targets* or *Imported Targets*.  It will now produce
  an error if such a linked target is missing.  Previously in this
  case CMake generated a link line that failed at build time. See
  policy "CMP0028".

* When the "project()" or "enable_language()" commands initialize
  support for a language, it is now an error if the full path to the
  compiler cannot be found and stored in the corresponding
  "CMAKE_<LANG>_COMPILER" variable.  This produces nicer error
  messages up front and stops processing when no working compiler is
  known to be available.

* Target sources specified with the "add_library()" or
  "add_executable()" command learned to reject items which require an
  undocumented extra layer of variable expansion. See policy
  "CMP0049".

* Use of "add_custom_command()" undocumented "SOURCE" signatures now
  results in an error.  See policy "CMP0050".


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

* Compatibility options supporting code written for CMake versions
  prior to 2.4 have been removed.

* Several long-outdated commands that should no longer be called
  have been disallowed in new code by policies:

  * Policy "CMP0029" disallows "subdir_depends()"

  * Policy "CMP0030" disallows "use_mangled_mesa()"

  * Policy "CMP0031" disallows "load_command()"

  * Policy "CMP0032" disallows "output_required_files()"

  * Policy "CMP0033" disallows "export_library_dependencies()"

  * Policy "CMP0034" disallows "utility_source()"

  * Policy "CMP0035" disallows "variable_requires()"

  * Policy "CMP0036" disallows "build_name()"

* The "cmake(1)" "-i" wizard mode has been removed. Instead use an
  interactive dialog such as "ccmake(1)" or use the "-D" option to set
  cache values from the command line.

* The builtin documentation formatters that supported command-line
  options such as "--help-man" and "--help-html" have been removed in
  favor of the above-mentioned new documentation system.  These and
  other command-line options that used to generate man- and html-
  formatted pages no longer work.  The "cmake(1)" "--help-custom-
  modules" option now produces a warning at runtime and generates a
  minimal document that reports the limitation.

* The "COMPILE_DEFINITIONS_<CONFIG>" directory properties and the
  "COMPILE_DEFINITIONS_<CONFIG>" target properties have been
  deprecated.  Instead set the corresponding "COMPILE_DEFINITIONS"
  directory property or "COMPILE_DEFINITIONS" target property and use
  "generator expressions" like "$<CONFIG:...>" to specify per-
  configuration definitions. See policy "CMP0043".

* The "LOCATION" target property should no longer be read from non-
  IMPORTED targets.  It does not make sense in multi-configuration
  generators since the build configuration is not known while
  configuring the project.  It has been superseded by the
  "$<TARGET_FILE>" generator expression.  See policy "CMP0026".

* The "COMPILE_FLAGS" target property is now documented as
  deprecated, though no warning is issued.  Use the "COMPILE_OPTIONS"
  target property or the "target_compile_options()" command instead.

* The "GenerateExportHeader" module "add_compiler_export_flags"
  function is now deprecated.  It has been superseded by the
  "<LANG>_VISIBILITY_PRESET" and "VISIBILITY_INLINES_HIDDEN" target
  properties.


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

* The version scheme was changed to use only two components for the
  feature level instead of three.  The third component will now be
  used for bug-fix releases or the date of development versions. See
  the "CMAKE_VERSION" variable documentation for details.

* The default install locations of CMake itself on Windows and OS X
  no longer contain the CMake version number.  This allows for easy
  replacement without re-generating local build trees manually.

* Generators for Visual Studio 10 (2010) and later were renamed to
  include the product year like generators for older VS versions:

  * "Visual Studio 10" -> "Visual Studio 10 2010"

  * "Visual Studio 11" -> "Visual Studio 11 2012"

  * "Visual Studio 12" -> "Visual Studio 12 2013"

  This clarifies which generator goes with each Visual Studio version.
  The old names are recognized for compatibility.

* The "CMAKE_<LANG>_COMPILER_ID" value for Apple-provided Clang is
  now "AppleClang".  It must be distinct from upstream Clang because
  the version numbers differ. See policy "CMP0025".

* The "CMAKE_<LANG>_COMPILER_ID" value for "qcc" on QNX is now
  "QCC". It must be distinct from "GNU" because the command-line
  options differ.  See policy "CMP0047".

* On 64-bit OS X the "CMAKE_HOST_SYSTEM_PROCESSOR" value is now
  correctly detected as "x86_64" instead of "i386".

* On OS X, CMake learned to enable behavior specified by the
  "MACOSX_RPATH" target property by default.  This activates use of
  "@rpath" for runtime shared library searches. See policy "CMP0042".

* The "build_command()" command now returns a "cmake(1)" "--build"
  command line instead of a direct invocation of the native build
  tool.  When using "Visual Studio" generators, CMake and CTest no
  longer require "CMAKE_MAKE_PROGRAM" to be located up front.
  Selection of the proper msbuild or devenv tool is now performed as
  late as possible when the solution (".sln") file is available so it
  can depend on project content.

* The "cmake(1)" "--build" command now shares its own stdout and
  stderr pipes with the native build tool by default. The "--use-
  stderr" option that once activated this is now ignored.

* The "$<C_COMPILER_ID:...>" and "$<CXX_COMPILER_ID:...>" "generator
  expressions" used to perform case-insensitive comparison but have
  now been corrected to perform case-sensitive comparison. See policy
  "CMP0044".

* The builtin "edit_cache" target will no longer select "ccmake(1)"
  by default when no interactive terminal will be available (e.g. with
  "Ninja" or an IDE generator). Instead "cmake-gui(1)" will be
  preferred if available.

* The "ExternalProject" download step learned to re-attempt download
  in certain cases to be more robust to temporary network failure.

* The "FeatureSummary" no longer lists transitive dependencies since
  they were not directly requested by the current project.

* The "cmake-mode.el" major Emacs editing mode has been cleaned up
  and enhanced in several ways.

* Include directories specified in the
  "INTERFACE_INCLUDE_DIRECTORIES" of *Imported Targets* are treated as
  "SYSTEM" includes by default when handled as *usage requirements*.