cmake-presets(7)¶
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:
{ "version": 1, "cmakeMinimumRequired": { "major": 3, "minor": 19, "patch": 0 }, "configurePresets": [ { "name": "default", "displayName": "Default Config", "description": "Default build using Ninja generator", "generator": "Ninja", "binaryDir": "${sourceDir}/build/default", "cacheVariables": { "FIRST_CACHE_VARIABLE": { "type": "BOOL", "value": "OFF" }, "SECOND_CACHE_VARIABLE": "ON" }, "environment": { "MY_ENVIRONMENT_VARIABLE": "Test", "PATH": "$env{HOME}/ninja/bin:$penv{PATH}" }, "vendor": { "example.com/ExampleIDE/1.0": { "autoFormat": true } } }, { "name": "ninja-multi", "inherits": "default", "displayName": "Ninja Multi-Config", "description": "Default build using Ninja Multi-Config generator", "generator": "Ninja Multi-Config" } ], "vendor": { "example.com/ExampleIDE/1.0": { "autoFormat": false } } }The root object recognizes the following fields:
version
A required integer representing the version of the JSON schema. Currently, the only supported version is 1.
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 useexample.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. Each preset may contain the following fields:
name
A required string representing the machine-friendly name of the preset. This identifier is used in the
--preset
argument. There must not be two presets in the union ofCMakePresets.json
andCMakeUserPresets.json
in the same directory with the same name.
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 theCMake GUI
, and does not have to have a validgenerator
orbinaryDir
, even from inheritance.hidden
presets are intended to be used as a base for other presets to inherit via theinherits
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 (exceptname
,hidden
,inherits
,description
, anddisplayName
), but can override them as desired. If multipleinherits
presets provide conflicting values for the same field, the earlier preset in theinherits
list will be preferred. Presets inCMakePresets.json
may not inherit from presets inCMakeUserPresets.json
.This field can also be a string, which is equivalent to an array containing one string.
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-presetvendor
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 theinherits
preset (unless this preset ishidden
).Note that for Visual Studio generators, unlike in the command line
-G
argument, you cannot include the platform name in the generator name. Use thearchitecture
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
ortoolset
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
andtoolset
fields. In that case, CMake will ignore the field, but the IDE can use them to set up the environment before invoking CMake.
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 theinherits
preset (unless this preset ishidden
).
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 ofBOOL
), 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 owncacheVariables
and thecacheVariables
from all its parents. If multiple presets in this union define the same variable, the standard rules ofinherits
are applied. Setting a variable tonull
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, ifENV_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 ownenvironment
and theenvironment
from all its parents. If multiple presets in this union define the same variable, the standard rules ofinherits
are applied. Setting a variable tonull
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 tofalse
iferrors.dev
is set totrue
.
deprecated
An optional boolean. Equivalent to passing
-Wdeprecated
or-Wno-deprecated
on the command line. This may not be set tofalse
iferrors.deprecated
is set totrue
.
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 totrue
ifwarnings.dev
is set tofalse
.
deprecated
An optional boolean. Equivalent to passing
-Werror=deprecated
or-Wno-error=deprecated
on the command line. This may not be set totrue
ifwarnings.deprecated
is set tofalse
.
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.As mentioned above, some fields support macro expansion. Macros are recognized in the form
$<macro-namespace>{<macro-name>}
. All macros are evaluated in the context of the preset being used, even if the macro is in a field that was inherited from another preset. For example, if theBase
preset sets variablePRESET_NAME
to${presetName}
, and theDerived
preset inherits fromBase
,PRESET_NAME
will be set toDerived
.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 besource
.
${presetName}
Name specified in the preset’s
name
field.
${generator}
Generator specified in the preset’s
generator
field.
${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 theenvironment
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
$env{<variable-name>}
, except that the value only comes from the parent environment, and never from theenvironment
field. This allows you to prepend or append values to existing environment variables. For example, settingPATH
to/path/to/ninja/bin:$penv{PATH}
will prepend/path/to/ninja/bin
to thePATH
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¶
This file
provides a machine-readable
JSON schema for the CMakePresets.json
format.