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Methods available in BUILD files. See also the Build Encyclopedia for extra functions and build rules, which can also be used in BUILD files.

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Members

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depset

Creates a depset. The direct parameter is a list of direct elements of the depset, and transitive parameter is a list of depsets whose elements become indirect elements of the created depset. The order in which elements are returned when the depset is converted to a list is specified by the order parameter. See the Depsets overview for more information. All elements (direct and indirect) of a depset must be of the same type, as obtained by the expression type(x). Because a hash-based set is used to eliminate duplicates during iteration, all elements of a depset should be hashable. However, this invariant is not currently checked consistently in all constructors. Use the —incompatible_always_check_depset_elements flag to enable consistent checking; this will be the default behavior in future releases; see Issue 10313. In addition, elements must currently be immutable, though this restriction will be relaxed in future. The order of the created depset should be compatible with the order of its transitive depsets. "default" order is compatible with any other order, all other orders are only compatible with themselves.

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Parameters

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existing_rule

Returns an immutable dict-like object that describes the attributes of a rule instantiated in this thread’s package, or None if no rule instance of that name exists. Here, an immutable dict-like object means a deeply immutable object x supporting dict-like iteration, len(x), name in x, x[name], x.get(name), x.items(), x.keys(), and x.values(). The result contains an entry for each attribute, with the exception of private ones (whose names do not start with a letter) and a few unrepresentable legacy attribute types. In addition, the dict contains entries for the rule instance’s name and kind (for example, 'cc_binary'). The values of the result represent attribute values as follows:
  • Attributes of type str, int, and bool are represented as is.
  • Labels are converted to strings of the form ':foo' for targets in the same package or '//pkg:name' for targets in a different package.
  • Lists are represented as tuples, and dicts are converted to new, mutable dicts. Their elements are recursively converted in the same fashion.
  • select values are returned with their contents transformed as described above.
  • Attributes for which no value was specified during rule instantiation and whose default value is computed are excluded from the result. (Computed defaults cannot be computed until the analysis phase.).
If possible, use this function only in implementation functions of rule finalizer symbolic macros. Use of this function in other contexts is not recommened, and will be disabled in a future Bazel release; it makes BUILD files brittle and order-dependent. Also, beware that it differs subtly from the two other conversions of rule attribute values from internal form to Starlark: one used by computed defaults, the other used by ctx.attr.foo.

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Parameters

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existing_rules

Returns an immutable dict-like object describing the rules so far instantiated in this thread’s package. Each entry of the dict-like object maps the name of the rule instance to the result that would be returned by existing_rule(name). Here, an immutable dict-like object means a deeply immutable object x supporting dict-like iteration, len(x), name in x, x[name], x.get(name), x.items(), x.keys(), and x.values(). If possible, use this function only in implementation functions of rule finalizer symbolic macros. Use of this function in other contexts is not recommened, and will be disabled in a future Bazel release; it makes BUILD files brittle and order-dependent.

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exports_files

Specifies a list of files belonging to this package that are exported to other packages.

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Parameters

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glob

Glob returns a new, mutable, sorted list of every file in the current package that:
  • Matches at least one pattern in include.
  • Does not match any of the patterns in exclude (default []).
If the exclude_directories argument is enabled (set to 1), files of type directory will be omitted from the results (default 1).

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Parameters

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module_name

The name of the Bazel module associated with the repo this package is in. If this package is from a repo defined in WORKSPACE instead of MODULE.bazel, this is empty. For repos generated by module extensions, this is the name of the module hosting the extension. It’s the same as the module.name field seen in module_ctx.modules. May return None.

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module_version

The version of the Bazel module associated with the repo this package is in. If this package is from a repo defined in WORKSPACE instead of MODULE.bazel, this is empty. For repos generated by module extensions, this is the version of the module hosting the extension. It’s the same as the module.version field seen in module_ctx.modules. May return None.

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package

Declares metadata that applies to every rule in the package. It must be called at most once within a package (BUILD file). If called, it should be the first call in the BUILD file, right after the load() statements.

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Parameters

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package_default_visibility

Returns the default visibility of the package being evaluated. This is the value of the default_visibility parameter of package(), extended to include the package itself.

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package_group

This function defines a set of packages and assigns a label to the group. The label can be referenced in visibility attributes.

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Parameters

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package_name

The name of the package being evaluated, without the repository name. For example, in the BUILD file some/package/BUILD, its value will be some/package. If the BUILD file calls a function defined in a .bzl file, package_name() will match the caller BUILD file package. The value will always be an empty string for the root package.

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package_relative_label

Converts the input string into a Label object, in the context of the package currently being initialized (that is, the BUILD file for which the current macro is executing). If the input is already a Label, it is returned unchanged. This function may only be called while evaluating a BUILD file and the macros it directly or indirectly calls; it may not be called in (for instance) a rule implementation function. The result of this function is the same Label value as would be produced by passing the given string to a label-valued attribute of a target declared in the BUILD file. Usage note: The difference between this function and Label() is that Label() uses the context of the package of the .bzl file that called it, not the package of the BUILD file. Use Label() when you need to refer to a fixed target that is hardcoded into the macro, such as a compiler. Use package_relative_label() when you need to normalize a label string supplied by the BUILD file to a Label object. (There is no way to convert a string to a Label in the context of a package other than the BUILD file or the calling .bzl file. For that reason, outer macros should always prefer to pass Label objects to inner macros rather than label strings.)ctx.package_relative_label() provides the same functionality within a rule or aspect implementation function.

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Parameters

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repo_name

The canonical name of the repository containing the package currently being evaluated, with no leading at-signs.

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repository_name

Experimental. This API is experimental and may change at any time. Please do not depend on it. It may be enabled on an experimental basis by setting --+incompatible_enable_deprecated_label_apis Deprecated. Prefer to use repo_name instead, which doesn’t contain the spurious leading at-sign, but behaves identically otherwise. The canonical name of the repository containing the package currently being evaluated, with a single at-sign (@) prefixed. For example, in packages that are called into existence by the WORKSPACE stanza local_repository(name='local', path=...) it will be set to @local. In packages in the main repository, it will be set to @.

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select

select() is the helper function that makes a rule attribute configurable. See build encyclopedia for details.

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Parameters

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subpackages

Returns a new mutable list of every direct subpackage of the current package, regardless of file-system directory depth. List returned is sorted and contains the names of subpackages relative to the current package. It is advised to prefer using the methods in bazel_skylib.subpackages module rather than calling this function directly.

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Parameters