CMake/Help/manual/cmake-presets.7.rst

.. cmake-manual-description: CMakePresets.json

cmake-presets(7)
****************

.. only:: html

   .. contents::

Introduction
============

One problem that CMake users often face is sharing settings with other people
for common ways to configure a project. This may be done to support CI builds,
or for users who frequently use the same build. CMake supports two files,
``CMakePresets.json`` and ``CMakeUserPresets.json``, that allow users to
specify common configure options and share them with others.

``CMakePresets.json`` and ``CMakeUserPresets.json`` live in the project's root
directory. They both have exactly the same format, and both are optional
(though at least one must be present if ``--preset`` is specified.)
``CMakePresets.json`` is meant to save project-wide builds, while
``CMakeUserPresets.json`` is meant for developers to save their own local
builds. ``CMakePresets.json`` may be checked into a version control system, and
``CMakeUserPresets.json`` should NOT be checked in. For example, if a project
is using Git, ``CMakePresets.json`` may be tracked, and
``CMakeUserPresets.json`` should be added to the ``.gitignore``.

Format
======

The files are a JSON document with an object as the root:

.. literalinclude:: presets/example.json
  :language: json

The root object recognizes the following fields:

``version``

  A required integer representing the version of the JSON schema.
  The supported versions are ``1``, ``2``, and ``3``.

``cmakeMinimumRequired``

  An optional object representing the minimum version of CMake needed to
  build this project. This object consists of the following fields:

  ``major``

    An optional integer representing the major version.

  ``minor``

    An optional integer representing the minor version.

  ``patch``

    An optional integer representing the patch version.

``vendor``

  An optional map containing vendor-specific information. CMake does not
  interpret the contents of this field except to verify that it is a map if
  it does exist. However, the keys should be a vendor-specific domain name
  followed by a ``/``-separated path. For example, the Example IDE 1.0 could
  use ``example.com/ExampleIDE/1.0``. The value of each field can be anything
  desired by the vendor, though will typically be a map.

``configurePresets``

  An optional array of `Configure Preset`_ objects.
  This is allowed in preset files specifying version ``1`` or above.

``buildPresets``

  An optional array of `Build Preset`_ objects.
  This is allowed in preset files specifying version ``2`` or above.

``testPresets``

  An optional array of `Test Preset`_ objects.
  This is allowed in preset files specifying version ``2`` or above.

Configure Preset
^^^^^^^^^^^^^^^^

Each entry of the ``configurePresets`` array is a JSON object
that may contain the following fields:

``name``

  A required string representing the machine-friendly name of the preset.
  This identifier is used in the :ref:`cmake --preset <CMake Options>` option.
  There must not be two configure presets in the union of ``CMakePresets.json``
  and ``CMakeUserPresets.json`` in the same directory with the same name.
  However, a configure preset may have the same name as a build or test preset.

``hidden``

  An optional boolean specifying whether or not a preset should be hidden.
  If a preset is hidden, it cannot be used in the ``--preset=`` argument,
  will not show up in the :manual:`CMake GUI <cmake-gui(1)>`, and does not
  have to have a valid ``generator`` or ``binaryDir``, even from
  inheritance. ``hidden`` presets are intended to be used as a base for
  other presets to inherit via the ``inherits`` field.

``inherits``

  An optional array of strings representing the names of presets to inherit
  from. The preset will inherit all of the fields from the ``inherits``
  presets by default (except ``name``, ``hidden``, ``inherits``,
  ``description``, and ``displayName``), but can override them as
  desired. If multiple ``inherits`` presets provide conflicting values for
  the same field, the earlier preset in the ``inherits`` list will be
  preferred. Presets in ``CMakePresets.json`` may not inherit from presets
  in ``CMakeUserPresets.json``.

  This field can also be a string, which is equivalent to an array
  containing one string.

``condition``

  An optional `Condition`_ object. This is allowed in preset files specifying
  version ``3`` or above.

``vendor``

  An optional map containing vendor-specific information. CMake does not
  interpret the contents of this field except to verify that it is a map
  if it does exist. However, it should follow the same conventions as the
  root-level ``vendor`` field. If vendors use their own per-preset
  ``vendor`` field, they should implement inheritance in a sensible manner
  when appropriate.

``displayName``

  An optional string with a human-friendly name of the preset.

``description``

  An optional string with a human-friendly description of the preset.

``generator``

  An optional string representing the generator to use for the preset. If
  ``generator`` is not specified, it must be inherited from the
  ``inherits`` preset (unless this preset is ``hidden``). In version ``3``
  or above, this field may be omitted to fall back to regular generator
  discovery procedure.

  Note that for Visual Studio generators, unlike in the command line ``-G``
  argument, you cannot include the platform name in the generator name. Use
  the ``architecture`` field instead.

``architecture``, ``toolset``

  Optional fields representing the platform and toolset, respectively, for
  generators that support them. Each may be either a string or an object
  with the following fields:

  ``value``

    An optional string representing the value.

  ``strategy``

    An optional string telling CMake how to handle the ``architecture`` or
    ``toolset`` field. Valid values are:

    ``"set"``

      Set the respective value. This will result in an error for generators
      that do not support the respective field.

    ``"external"``

      Do not set the value, even if the generator supports it. This is
      useful if, for example, a preset uses the Ninja generator, and an IDE
      knows how to set up the Visual C++ environment from the
      ``architecture`` and ``toolset`` fields. In that case, CMake will
      ignore the field, but the IDE can use them to set up the environment
      before invoking CMake.

``toolchainFile``

  An optional string representing the path to the toolchain file.
  This field supports `macro expansion`_. If a relative path is specified,
  it is calculated relative to the build directory, and if not found,
  relative to the source directory. Takes precedence over any `CMAKE_TOOLCHAIN_FILE`
  value. This is allowed in preset files specifying version ``3`` or above.

``binaryDir``

  An optional string representing the path to the output binary directory.
  This field supports `macro expansion`_. If a relative path is specified,
  it is calculated relative to the source directory. If ``binaryDir`` is not
  specified, it must be inherited from the ``inherits`` preset (unless this
  preset is ``hidden``). In version ``3`` or above, this field may be
  omitted.

``installDir``

  An optional string representing the path to the installation directory.
  This field supports `macro expansion`_. If a relative path is specified,
  it is calculated relative to the source directory. This is allowed in
  preset files specifying version ``3`` or above.

``cmakeExecutable``

  An optional string representing the path to the CMake executable to use
  for this preset. This is reserved for use by IDEs, and is not used by
  CMake itself. IDEs that use this field should expand any macros in it.

``cacheVariables``

  An optional map of cache variables. The key is the variable name (which
  may not be an empty string), and the value is either ``null``, a boolean
  (which is equivalent to a value of ``"TRUE"`` or ``"FALSE"`` and a type
  of ``BOOL``), a string representing the value of the variable (which
  supports `macro expansion`_), or an object with the following fields:

  ``type``

    An optional string representing the type of the variable.

  ``value``

    A required string or boolean representing the value of the variable.
    A boolean is equivalent to ``"TRUE"`` or ``"FALSE"``. This field
    supports `macro expansion`_.

  Cache variables are inherited through the ``inherits`` field, and the
  preset's variables will be the union of its own ``cacheVariables`` and
  the ``cacheVariables`` from all its parents. If multiple presets in this
  union define the same variable, the standard rules of ``inherits`` are
  applied. Setting a variable to ``null`` causes it to not be set, even if
  a value was inherited from another preset.

``environment``

  An optional map of environment variables. The key is the variable name
  (which may not be an empty string), and the value is either ``null`` or
  a string representing the value of the variable. Each variable is set
  regardless of whether or not a value was given to it by the process's
  environment. This field supports `macro expansion`_, and environment
  variables in this map may reference each other, and may be listed in any
  order, as long as such references do not cause a cycle (for example,
  if ``ENV_1`` is ``$env{ENV_2}``, ``ENV_2`` may not be ``$env{ENV_1}``.)

  Environment variables are inherited through the ``inherits`` field, and
  the preset's environment will be the union of its own ``environment`` and
  the ``environment`` from all its parents. If multiple presets in this
  union define the same variable, the standard rules of ``inherits`` are
  applied. Setting a variable to ``null`` causes it to not be set, even if
  a value was inherited from another preset.

``warnings``

  An optional object specifying the warnings to enable. The object may
  contain the following fields:

  ``dev``

    An optional boolean. Equivalent to passing ``-Wdev`` or ``-Wno-dev``
    on the command line. This may not be set to ``false`` if ``errors.dev``
    is set to ``true``.

  ``deprecated``

    An optional boolean. Equivalent to passing ``-Wdeprecated`` or
    ``-Wno-deprecated`` on the command line. This may not be set to
    ``false`` if ``errors.deprecated`` is set to ``true``.

  ``uninitialized``

    An optional boolean. Setting this to ``true`` is equivalent to passing
    ``--warn-uninitialized`` on the command line.

  ``unusedCli``

    An optional boolean. Setting this to ``false`` is equivalent to passing
    ``--no-warn-unused-cli`` on the command line.

  ``systemVars``

    An optional boolean. Setting this to ``true`` is equivalent to passing
    ``--check-system-vars`` on the command line.

``errors``

  An optional object specifying the errors to enable. The object may
  contain the following fields:

  ``dev``

    An optional boolean. Equivalent to passing ``-Werror=dev`` or
    ``-Wno-error=dev`` on the command line. This may not be set to ``true``
    if ``warnings.dev`` is set to ``false``.

  ``deprecated``

    An optional boolean. Equivalent to passing ``-Werror=deprecated`` or
    ``-Wno-error=deprecated`` on the command line. This may not be set to
    ``true`` if ``warnings.deprecated`` is set to ``false``.

``debug``

  An optional object specifying debug options. The object may contain the
  following fields:

  ``output``

    An optional boolean. Setting this to ``true`` is equivalent to passing
    ``--debug-output`` on the command line.

  ``tryCompile``

    An optional boolean. Setting this to ``true`` is equivalent to passing
    ``--debug-trycompile`` on the command line.

  ``find``

    An optional boolean. Setting this to ``true`` is equivalent to passing
    ``--debug-find`` on the command line.

Build Preset
^^^^^^^^^^^^

Each entry of the ``buildPresets`` array is a JSON object
that may contain the following fields:

``name``

  A required string representing the machine-friendly name of the preset.
  This identifier is used in the
  :ref:`cmake --build --preset <Build Tool Mode>` option.
  There must not be two build presets in the union of ``CMakePresets.json``
  and ``CMakeUserPresets.json`` in the same directory with the same name.
  However, a build preset may have the same name as a configure or test preset.

``hidden``

  An optional boolean specifying whether or not a preset should be hidden.
  If a preset is hidden, it cannot be used in the ``--preset`` argument
  and does not have to have a valid ``configurePreset``, even from
  inheritance. ``hidden`` presets are intended to be used as a base for
  other presets to inherit via the ``inherits`` field.

``inherits``

  An optional array of strings representing the names of presets to
  inherit from. The preset will inherit all of the fields from the
  ``inherits`` presets by default (except ``name``, ``hidden``,
  ``inherits``, ``description``, and ``displayName``), but can override
  them as desired. If multiple ``inherits`` presets provide conflicting
  values for the same field, the earlier preset in the ``inherits`` list
  will be preferred. Presets in ``CMakePresets.json`` may not inherit from
  presets in ``CMakeUserPresets.json``.

  This field can also be a string, which is equivalent to an array
  containing one string.

``condition``

  An optional `Condition`_ object. This is allowed in preset files specifying
  version ``3`` or above.

``vendor``

  An optional map containing vendor-specific information. CMake does not
  interpret the contents of this field except to verify that it is a map
  if it does exist. However, it should follow the same conventions as the
  root-level ``vendor`` field. If vendors use their own per-preset
  ``vendor`` field, they should implement inheritance in a sensible manner
  when appropriate.

``displayName``

  An optional string with a human-friendly name of the preset.

``description``

  An optional string with a human-friendly description of the preset.

``environment``

  An optional map of environment variables. The key is the variable name
  (which may not be an empty string), and the value is either ``null`` or
  a string representing the value of the variable. Each variable is set
  regardless of whether or not a value was given to it by the process's
  environment. This field supports macro expansion, and environment
  variables in this map may reference each other, and may be listed in any
  order, as long as such references do not cause a cycle (for example, if
  ``ENV_1`` is ``$env{ENV_2}``, ``ENV_2`` may not be ``$env{ENV_1}``.)

  Environment variables are inherited through the ``inherits`` field, and
  the preset's environment will be the union of its own ``environment``
  and the ``environment`` from all its parents. If multiple presets in
  this union define the same variable, the standard rules of ``inherits``
  are applied. Setting a variable to ``null`` causes it to not be set,
  even if a value was inherited from another preset.

``configurePreset``

  An optional string specifying the name of a configure preset to
  associate with this build preset. If ``configurePreset`` is not
  specified, it must be inherited from the inherits preset (unless this
  preset is hidden). The build directory is inferred from the configure
  preset, so the build will take place in the same ``binaryDir`` that the
  configuration did.

``inheritConfigureEnvironment``

  An optional boolean that defaults to true. If true, the environment
  variables from the associated configure preset are inherited after all
  inherited build preset environments, but before environment variables
  explicitly specified in this build preset.

``jobs``

  An optional integer. Equivalent to passing ``--parallel`` or ``-j`` on
  the command line.

``targets``

  An optional string or array of strings. Equivalent to passing
  ``--target`` or ``-t`` on the command line. Vendors may ignore the
  targets property or hide build presets that explicitly specify targets.
  This field supports macro expansion.

``configuration``

  An optional string. Equivalent to passing ``--config`` on the command
  line.

``cleanFirst``

  An optional bool. If true, equivalent to passing ``--clean-first`` on
  the command line.

``verbose``

  An optional bool. If true, equivalent to passing ``--verbose`` on the
  command line.

``nativeToolOptions``

  An optional array of strings. Equivalent to passing options after ``--``
  on the command line. The array values support macro expansion.

Test Preset
^^^^^^^^^^^

Each entry of the ``testPresets`` array is a JSON object
that may contain the following fields:

``name``

  A required string representing the machine-friendly name of the preset.
  This identifier is used in the :ref:`ctest --preset <CTest Options>` option.
  There must not be two test presets in the union of ``CMakePresets.json``
  and ``CMakeUserPresets.json`` in the same directory with the same name.
  However, a test preset may have the same name as a configure or build preset.

``hidden``

  An optional boolean specifying whether or not a preset should be hidden.
  If a preset is hidden, it cannot be used in the ``--preset`` argument
  and does not have to have a valid ``configurePreset``, even from
  inheritance. ``hidden`` presets are intended to be used as a base for
  other presets to inherit via the ``inherits`` field.

``inherits``

  An optional array of strings representing the names of presets to
  inherit from. The preset will inherit all of the fields from the
  ``inherits`` presets by default (except ``name``, ``hidden``,
  ``inherits``, ``description``, and ``displayName``), but can override
  them as desired. If multiple ``inherits`` presets provide conflicting
  values for the same field, the earlier preset in the ``inherits`` list
  will be preferred. Presets in ``CMakePresets.json`` may not inherit from
  presets in ``CMakeUserPresets.json``.

  This field can also be a string, which is equivalent to an array
  containing one string.

``condition``

  An optional `Condition`_ object. This is allowed in preset files specifying
  version ``3`` or above.

``vendor``

  An optional map containing vendor-specific information. CMake does not
  interpret the contents of this field except to verify that it is a map
  if it does exist. However, it should follow the same conventions as the
  root-level ``vendor`` field. If vendors use their own per-preset
  ``vendor`` field, they should implement inheritance in a sensible manner
  when appropriate.

``displayName``

  An optional string with a human-friendly name of the preset.

``description``

  An optional string with a human-friendly description of the preset.

``environment``

  An optional map of environment variables. The key is the variable name
  (which may not be an empty string), and the value is either ``null`` or
  a string representing the value of the variable. Each variable is set
  regardless of whether or not a value was given to it by the process's
  environment. This field supports macro expansion, and environment
  variables in this map may reference each other, and may be listed in any
  order, as long as such references do not cause a cycle (for example, if
  ``ENV_1`` is ``$env{ENV_2}``, ``ENV_2`` may not be ``$env{ENV_1}``.)

  Environment variables are inherited through the ``inherits`` field, and
  the preset's environment will be the union of its own ``environment``
  and the ``environment`` from all its parents. If multiple presets in
  this union define the same variable, the standard rules of ``inherits``
  are applied. Setting a variable to ``null`` causes it to not be set,
  even if a value was inherited from another preset.

``configurePreset``

  An optional string specifying the name of a configure preset to
  associate with this test preset. If ``configurePreset`` is not
  specified, it must be inherited from the inherits preset (unless this
  preset is hidden). The build directory is inferred from the configure
  preset, so tests will run in the same ``binaryDir`` that the
  configuration did and build did.

``inheritConfigureEnvironment``

  An optional boolean that defaults to true. If true, the environment
  variables from the associated configure preset are inherited after all
  inherited test preset environments, but before environment variables
  explicitly specified in this test preset.

``configuration``

  An optional string. Equivalent to passing ``--build-config`` on the
  command line.

``overwriteConfigurationFile``

  An optional array of configuration options to overwrite options
  specified in the CTest configuration file. Equivalent to passing
  ``--overwrite`` for each value in the array. The array values
  support macro expansion.

``output``

  An optional object specifying output options. The object may contain the
  following fields.

  ``shortProgress``

    An optional bool. If true, equivalent to passing ``--progress`` on the
    command line.

  ``verbosity``

    An optional string specifying verbosity level. Must be one of the
    following:

    ``default``

      Equivalent to passing no verbosity flags on the command line.

    ``verbose``

      Equivalent to passing ``--verbose`` on the command line.

    ``extra``

      Equivalent to passing ``--extra-verbose`` on the command line.

  ``debug``

    An optional bool. If true, equivalent to passing ``--debug`` on the
    command line.

  ``outputOnFailure``

    An optional bool. If true, equivalent to passing
    ``--output-on-failure`` on the command line.

  ``quiet``

    An optional bool. If true, equivalent to passing ``--quiet`` on the
    command line.

  ``outputLogFile``

    An optional string specifying a path to a log file. Equivalent to
    passing ``--output-log`` on the command line. This field supports
    macro expansion.

  ``labelSummary``

    An optional bool. If false, equivalent to passing
    ``--no-label-summary`` on the command line.

  ``subprojectSummary``

    An optional bool. If false, equivalent to passing
    ``--no-subproject-summary`` on the command line.

  ``maxPassedTestOutputSize``

    An optional integer specifying the maximum output for passed tests in
    bytes. Equivalent to passing ``--test-output-size-passed`` on the
    command line.

  ``maxFailedTestOutputSize``

    An optional integer specifying the maximum output for failed tests in
    bytes. Equivalent to passing ``--test-output-size-failed`` on the
    command line.

  ``maxTestNameWidth``

    An optional integer specifying the maximum width of a test name to
    output. Equivalent to passing ``--max-width`` on the command line.

``filter``

  An optional object specifying how to filter the tests to run. The object
  may contain the following fields.

  ``include``

    An optional object specifying which tests to include. The object may
    contain the following fields.

    ``name``

      An optional string specifying a regex for test names. Equivalent to
      passing ``--tests-regex`` on the command line. This field supports
      macro expansion.


    ``label``

      An optional string specifying a regex for test labels. Equivalent to
      passing ``--label-regex`` on the command line. This field supports
      macro expansion.

    ``useUnion``

      An optional bool. Equivalent to passing ``--union`` on the command
      line.

    ``index``

      An optional object specifying tests to include by test index. The
      object may contain the following fields. Can also be an optional
      string specifying a file with the command line syntax for
      ``--tests-information``. If specified as a string, this field
      supports macro expansion.

      ``start``

        An optional integer specifying a test index to start testing at.

      ``end``

        An optional integer specifying a test index to stop testing at.

      ``stride``

        An optional integer specifying the increment.

      ``specificTests``

        An optional array of integers specifying specific test indices to
        run.

  ``exclude``

    An optional object specifying which tests to exclude. The object may
    contain the following fields.

    ``name``

      An optional string specifying a regex for test names. Equivalent to
      passing ``--exclude-regex`` on the command line. This field supports
      macro expansion.

    ``label``

      An optional string specifying a regex for test labels. Equivalent to
      passing ``--label-exclude`` on the command line. This field supports
      macro expansion.

    ``fixtures``

      An optional object specifying which fixtures to exclude from adding
      tests. The object may contain the following fields.

      ``any``

        An optional string specifying a regex for text fixtures to exclude
        from adding any tests. Equivalent to ``--fixture-exclude-any`` on
        the command line. This field supports macro expansion.

      ``setup``

        An optional string specifying a regex for text fixtures to exclude
        from adding setup tests. Equivalent to ``--fixture-exclude-setup``
        on the command line. This field supports macro expansion.

      ``cleanup``

        An optional string specifying a regex for text fixtures to exclude
        from adding cleanup tests. Equivalent to
        ``--fixture-exclude-cleanup`` on the command line. This field
        supports macro expansion.

``execution``

  An optional object specifying options for test execution. The object may
  contain the following fields.

  ``stopOnFailure``

    An optional bool. If true, equivalent to passing ``--stop-on-failure``
    on the command line.

  ``enableFailover``

    An optional bool. If true, equivalent to passing ``-F`` on the command
    line.

  ``jobs``

    An optional integer. Equivalent to passing ``--parallel`` on the
    command line.

  ``resourceSpecFile``

    An optional string. Equivalent to passing ``--resource-spec-file`` on
    the command line. This field supports macro expansion.

  ``testLoad``

    An optional integer. Equivalent to passing ``--test-load`` on the
    command line.

  ``showOnly``

    An optional string. Equivalent to passing ``--show-only`` on the
    command line. The string must be one of the following values:

    ``human``

    ``json-v1``

  ``repeat``

    An optional object specifying how to repeat tests. Equivalent to
    passing ``--repeat`` on the command line. The object must have the
    following fields.

    ``mode``

      A required string. Must be one of the following values:

      ``until-fail``

      ``until-pass``

      ``after-timeout``

    ``count``

      A required integer.

  ``interactiveDebugging``

    An optional bool. If true, equivalent to passing
    ``--interactive-debug-mode 1`` on the command line. If false,
    equivalent to passing ``--interactive-debug-mode 0`` on the command
    line.

  ``scheduleRandom``

    An optional bool. If true, equivalent to passing ``--schedule-random``
    on the command line.

  ``timeout``

    An optional integer. Equivalent to passing ``--timeout`` on the
    command line.

  ``noTestsAction``

    An optional string specifying the behavior if no tests are found. Must
    be one of the following values:

    ``default``

      Equivalent to not passing any value on the command line.

    ``error``

      Equivalent to passing ``--no-tests=error`` on the command line.

    ``ignore``

      Equivalent to passing ``--no-tests=ignore`` on the command line.

Condition
^^^^^^^^^

The ``condition`` field of a preset, allowed in preset files specifying version
``3`` or above, is used to determine whether or not the preset is enabled. For
example, this can be used to disable a preset on platforms other than Windows.
``condition`` may be either a boolean, ``null``, or an object. If it is a
boolean, the boolean indicates whether the preset is enabled or disabled. If it
is ``null``, the preset is enabled, but the ``null`` condition is not inherited
by any presets that may inherit from the preset. Sub-conditions (for example in
a ``not``, ``anyOf``, or ``allOf`` condition) may not be ``null``. If it is an
object, it has the following fields:

``type``

  A required string with one of the following values:

  ``"const"``

    Indicates that the condition is constant. This is equivalent to using a
    boolean in place of the object. The condition object will have the
    following additional fields:

    ``value``

      A required boolean which provides a constant value for the condition's
      evaluation.

  ``"equals"``

  ``"notEquals"``

    Indicates that the condition compares two strings to see if they are equal
    (or not equal). The condition object will have the following additional
    fields:

    ``lhs``

      First string to compare. This field supports macro expansion.

    ``rhs``

      Second string to compare. This field supports macro expansion.

  ``"inList"``

  ``"notInList"``

    Indicates that the condition searches for a string in a list of strings.
    The condition object will have the following additional fields:

    ``string``

      A required string to search for. This field supports macro expansion.

    ``list``

      A required list of strings to search. This field supports macro
      expansion, and uses short-circuit evaluation.

  ``"matches"``

  ``"notMatches"``

    Indicates that the condition searches for a regular expression in a string.
    The condition object will have the following additional fields:

    ``string``

      A required string to search. This field supports macro expansion.

    ``regex``

      A required regular expression to search for. This field supports macro
      expansion.

  ``"anyOf"``

  ``"allOf"``

    Indicates that the condition is an aggregation of zero or more nested
    conditions. The condition object will have the following additional fields:

    ``conditions``

      A required array of condition objects. These conditions use short-circuit
      evaluation.

  ``"not"``

    Indicates that the condition is an inversion of another condition. The
    condition object will have the following additional fields:

    ``condition``

      A required condition object.

Macro Expansion
^^^^^^^^^^^^^^^

As mentioned above, some fields support macro expansion. Macros are
recognized in the form ``$<macro-namespace>{<macro-name>}``. All macros are
evaluated in the context of the preset being used, even if the macro is in a
field that was inherited from another preset. For example, if the ``Base``
preset sets variable ``PRESET_NAME`` to ``${presetName}``, and the
``Derived`` preset inherits from ``Base``, ``PRESET_NAME`` will be set to
``Derived``.

It is an error to not put a closing brace at the end of a macro name. For
example, ``${sourceDir`` is invalid. A dollar sign (``$``) followed by
anything other than a left curly brace (``{``) with a possible namespace is
interpreted as a literal dollar sign.

Recognized macros include:

``${sourceDir}``

  Path to the project source directory.

``${sourceParentDir}``

  Path to the project source directory's parent directory.

``${sourceDirName}``

  The last filename component of ``${sourceDir}``. For example, if
  ``${sourceDir}`` is ``/path/to/source``, this would be ``source``.

``${presetName}``

  Name specified in the preset's ``name`` field.

``${generator}``

  Generator specified in the preset's ``generator`` field. For build and
  test presets, this will evaluate to the generator specified by
  ``configurePreset``.

``${hostSystemName}``

  The name of the host operating system. Contains the same value as
  :variable:`CMAKE_HOST_SYSTEM_NAME`. This is allowed in preset files
  specifying version ``3`` or above.

``${dollar}``

  A literal dollar sign (``$``).

``$env{<variable-name>}``

  Environment variable with name ``<variable-name>``. The variable name may
  not be an empty string. If the variable is defined in the ``environment``
  field, that value is used instead of the value from the parent environment.
  If the environment variable is not defined, this evaluates as an empty
  string.

  Note that while Windows environment variable names are case-insensitive,
  variable names within a preset are still case-sensitive. This may lead to
  unexpected results when using inconsistent casing. For best results, keep
  the casing of environment variable names consistent.

``$penv{<variable-name>}``

  Similar to ``$env{<variable-name>}``, except that the value only comes from
  the parent environment, and never from the ``environment`` field. This
  allows you to prepend or append values to existing environment variables.
  For example, setting ``PATH`` to ``/path/to/ninja/bin:$penv{PATH}`` will
  prepend ``/path/to/ninja/bin`` to the ``PATH`` environment variable. This
  is needed because ``$env{<variable-name>}`` does not allow circular
  references.

``$vendor{<macro-name>}``

  An extension point for vendors to insert their own macros. CMake will not
  be able to use presets which have a ``$vendor{<macro-name>}`` macro, and
  effectively ignores such presets. However, it will still be able to use
  other presets from the same file.

  CMake does not make any attempt to interpret ``$vendor{<macro-name>}``
  macros. However, to avoid name collisions, IDE vendors should prefix
  ``<macro-name>`` with a very short (preferably <= 4 characters) vendor
  identifier prefix, followed by a ``.``, followed by the macro name. For
  example, the Example IDE could have ``$vendor{xide.ideInstallDir}``.

Schema
======

:download:`This file </manual/presets/schema.json>` provides a machine-readable
JSON schema for the ``CMakePresets.json`` format.