| // Copyright 2018 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.devtools.build.lib.starlarkbuildapi; |
| |
| import com.google.devtools.build.docgen.annot.DocumentMethods; |
| import com.google.devtools.build.docgen.annot.StarlarkConstructor; |
| import com.google.devtools.build.lib.cmdline.Label; |
| import com.google.devtools.build.lib.packages.semantics.BuildLanguageOptions; |
| import com.google.devtools.build.lib.starlarkbuildapi.StarlarkConfigApi.BuildSettingApi; |
| import net.starlark.java.annot.Param; |
| import net.starlark.java.annot.ParamType; |
| import net.starlark.java.annot.StarlarkMethod; |
| import net.starlark.java.eval.Dict; |
| import net.starlark.java.eval.EvalException; |
| import net.starlark.java.eval.NoneType; |
| import net.starlark.java.eval.Sequence; |
| import net.starlark.java.eval.StarlarkCallable; |
| import net.starlark.java.eval.StarlarkFunction; |
| import net.starlark.java.eval.StarlarkThread; |
| |
| /** |
| * Interface for a global Starlark library containing rule-related helper and registration |
| * functions. |
| */ |
| @DocumentMethods |
| public interface StarlarkRuleFunctionsApi<FileApiT extends FileApi> { |
| |
| String EXEC_COMPATIBLE_WITH_PARAM = "exec_compatible_with"; |
| String TOOLCHAINS_PARAM = "toolchains"; |
| |
| String PROVIDES_DOC = |
| "A list of providers that the implementation function must return." |
| + "" |
| + "<p>It is an error if the implementation function omits any of the types of providers " |
| + "listed here from its return value. However, the implementation function may return " |
| + "additional providers not listed here." |
| + "" |
| + "<p>Each element of the list is an <code>*Info</code> object returned by " |
| + "<a href='globals.html#provider'><code>provider()</code></a>, except that a legacy " |
| + "provider is represented by its string name instead."; |
| |
| @StarlarkMethod( |
| name = "provider", |
| doc = |
| "Defines a provider symbol. The provider may be instantiated by calling it, or used" |
| + " directly as a key for retrieving an instance of that provider from a target." |
| + " Example:<br><pre class=\"language-python\">" // |
| + "MyInfo = provider()\n" |
| + "...\n" |
| + "def _my_library_impl(ctx):\n" |
| + " ...\n" |
| + " my_info = MyInfo(x = 2, y = 3)\n" |
| + " # my_info.x == 2\n" |
| + " # my_info.y == 3\n" |
| + " ..." // |
| + "</pre><p>See <a href='https://bazel.build/rules/rules#providers'>Rules" |
| + " (Providers)</a> for a comprehensive guide on how to use providers." // |
| + "<p>Returns a <a href='Provider.html#Provider'><code>Provider</code></a> callable " |
| + "value if <code>init</code> is not specified." // |
| + "<p>If <code>init</code> is specified, returns a tuple of 2 elements: a <a" |
| + " href='Provider.html#Provider'><code>Provider</code></a> callable value and a" |
| + " <em>raw constructor</em> callable value. See <a" |
| + " href='https://bazel.build/rules/rules#custom_initialization_of_providers'>Rules" |
| + " (Custom initialization of custom providers)</a> and the discussion of the" |
| + " <code>init</code> parameter below for details.", |
| parameters = { |
| @Param( |
| name = "doc", |
| named = true, |
| defaultValue = "''", |
| doc = |
| "A description of the provider that can be extracted by documentation generating" |
| + " tools."), |
| @Param( |
| name = "fields", |
| doc = |
| "If specified, restricts the set of allowed fields. <br>Possible values are:<ul> " |
| + " <li> list of fields:<br> <pre" |
| + " class=\"language-python\">provider(fields = ['a', 'b'])</pre><p> <li>" |
| + " dictionary field name -> documentation:<br> <pre" |
| + " class=\"language-python\">provider(\n" |
| + " fields = { 'a' : 'Documentation for a', 'b' : 'Documentation for b'" |
| + " })</pre></ul>All fields are optional.", |
| allowedTypes = { |
| @ParamType(type = Sequence.class, generic1 = String.class), |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| positional = false, |
| defaultValue = "None"), |
| @Param( |
| name = "init", |
| doc = |
| "An optional callback for preprocessing and validating the provider's field values" |
| + " during instantiation. If <code>init</code> is specified," |
| + " <code>provider()</code> returns a tuple of 2 elements: the normal provider" |
| + " symbol and a <em>raw constructor</em>." // |
| + "<p>A precise description follows; see <a" |
| + " href='https://bazel.build/rules/rules#custom_initialization_of_providers'>" |
| + "Rules (Custom initialization of providers)</a>" |
| + " for an intuitive discussion and use cases." // |
| + "<p>Let <code>P</code> be the provider symbol created by calling" |
| + " <code>provider()</code>. Conceptually, an instance of <code>P</code> is" |
| + " generated by calling a default constructor function <code>c(*args," |
| + " **kwargs)</code>, which does the following:" // |
| + "<ul>" // |
| + "<li>If <code>args</code> is non-empty, an error occurs.</li>" // |
| + "<li>If the <code>fields</code> parameter was specified when" |
| + " <code>provider()</code> was called, and if <code>kwargs</code> contains any" |
| + " key that was not listed in <code>fields</code>, an error occurs.</li>" // |
| + "<li>Otherwise, <code>c</code> returns a new instance that has, for each" |
| + " <code>k: v</code> entry in <code>kwargs</code>, a field named" |
| + " <code>k</code> with value <code>v</code>." // |
| + "</ul>" // |
| + "In the case where an <code>init</code> callback is <em>not</em> given, a" |
| + " call to the symbol <code>P</code> itself acts as a call to the default" |
| + " constructor function <code>c</code>; in other words, <code>P(*args," |
| + " **kwargs)</code> returns <code>c(*args, **kwargs)</code>. For example," // |
| + "<pre class=\"language-python\">" // |
| + "MyInfo = provider()\n" // |
| + "m = MyInfo(foo = 1)" // |
| + "</pre>" // |
| + "will straightforwardly make it so that <code>m</code> is a" |
| + " <code>MyInfo</code> instance with <code>m.foo == 1</code>." // |
| + "<p>But in the case where <code>init</code> is specified, the call" |
| + " <code>P(*args, **kwargs)</code> will perform the following steps" |
| + " instead:" // |
| + "<ol>" // |
| + "<li>The callback is invoked as <code>init(*args, **kwargs)</code>, that is," |
| + " with the exact same positional and keyword arguments as were passed to" |
| + " <code>P</code>.</li>" // |
| + "<li>The return value of <code>init</code> is expected to be a dictionary," |
| + " <code>d</code>, whose keys are field name strings. If it is not, an error" |
| + " occurs.</li>" // |
| + "<li>A new instance of <code>P</code> is generated as if by calling the" |
| + " default constructor with <code>d</code>'s entries as keyword arguments, as" |
| + " in <code>c(**d)</code>.</li>" // |
| + "</ol>" // |
| + "<p>NB: the above steps imply that an error occurs if <code>*args</code> or" |
| + " <code>**kwargs</code> does not match <code>init</code>'s signature, or the" |
| + " evaluation of <code>init</code>'s body fails (perhaps intentionally via a" |
| + " call to <a href=\"#fail\"><code>fail()</code></a>), or if the return value" |
| + " of <code>init</code> is not a dictionary with the expected schema." // |
| + "<p>In this way, the <code>init</code> callback generalizes normal provider" |
| + " construction by allowing positional arguments and arbitrary logic for" |
| + " preprocessing and validation. It does <em>not</em> enable circumventing the" |
| + " list of allowed <code>fields</code>." // |
| + "<p>When <code>init</code> is specified, the return value of" |
| + " <code>provider()</code> becomes a tuple <code>(P, r)</code>, where" |
| + " <code>r</code> is the <em>raw constructor</em>. In fact, the behavior of" |
| + " <code>r</code> is exactly that of the default constructor function" |
| + " <code>c</code> discussed above. Typically, <code>r</code> is bound to a" |
| + " variable whose name is prefixed with an underscore, so that only the" |
| + " current .bzl file has direct access to it:" // |
| + "<pre class=\"language-python\">" // |
| + "MyInfo, _new_myinfo = provider(init = ...)" // |
| + "</pre>", |
| named = true, |
| allowedTypes = { |
| @ParamType(type = StarlarkCallable.class), |
| @ParamType(type = NoneType.class), |
| }, |
| positional = false, |
| defaultValue = "None"), |
| }, |
| useStarlarkThread = true) |
| Object provider(String doc, Object fields, Object init, StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "rule", |
| doc = |
| "Creates a new rule, which can be called from a BUILD file or a macro to create targets." |
| + "<p>Rules must be assigned to global variables in a .bzl file; the name of the " |
| + "global variable is the rule's name." |
| + "<p>Test rules are required to have a name ending in <code>_test</code>, while all " |
| + "other rules must not have this suffix. (This restriction applies only to rules, " |
| + "not to their targets.)", |
| parameters = { |
| @Param( |
| name = "implementation", |
| named = true, |
| doc = |
| "the Starlark function implementing this rule, must have exactly one parameter: " |
| + "<a href=\"ctx.html\">ctx</a>. The function is called during the analysis " |
| + "phase for each instance of the rule. It can access the attributes " |
| + "provided by the user. It must create actions to generate all the declared " |
| + "outputs."), |
| @Param( |
| name = "test", |
| named = true, |
| defaultValue = "False", |
| doc = |
| "Whether this rule is a test rule, that is, whether it may be the subject of a" |
| + " <code>blaze test</code> command. All test rules are automatically" |
| + " considered <a href='#rule.executable'>executable</a>; it is unnecessary" |
| + " (and discouraged) to explicitly set <code>executable = True</code> for a" |
| + " test rule. See the <a" |
| + " href='https://bazel.build/rules/rules#executable_rules_and_test_rules'>" |
| + " Rules page</a> for more information."), |
| @Param( |
| name = "attrs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| doc = |
| "dictionary to declare all the attributes of the rule. It maps from an attribute " |
| + "name to an attribute object (see <a href=\"attr.html\">attr</a> module). " |
| + "Attributes starting with <code>_</code> are private, and can be used to " |
| + "add an implicit dependency on a label. The attribute <code>name</code> is " |
| + "implicitly added and must not be specified. Attributes " |
| + "<code>visibility</code>, <code>deprecation</code>, <code>tags</code>, " |
| + "<code>testonly</code>, and <code>features</code> are implicitly added and " |
| + "cannot be overridden. Most rules need only a handful of attributes. To " |
| + "limit memory usage, the rule function imposes a cap on the size of attrs."), |
| // TODO(bazel-team): need to give the types of these builtin attributes |
| @Param( |
| name = "outputs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| @ParamType(type = StarlarkFunction.class) // a function defined in Starlark |
| }, |
| named = true, |
| defaultValue = "None", |
| valueWhenDisabled = "None", |
| disableWithFlag = BuildLanguageOptions.INCOMPATIBLE_NO_RULE_OUTPUTS_PARAM, |
| doc = |
| "This parameter has been deprecated. Migrate rules to use" |
| + " <code>OutputGroupInfo</code> or <code>attr.output</code> instead. <p>A" |
| + " schema for defining predeclared outputs. Unlike <a" |
| + " href='attr.html#output'><code>output</code></a> and <a" |
| + " href='attr.html#output_list'><code>output_list</code></a> attributes, the" |
| + " user does not specify the labels for these files. See the <a" |
| + " href='https://bazel.build/rules/rules#files'>Rules page</a> for more on" |
| + " predeclared outputs.<p>The value of this argument is either a dictionary or" |
| + " a callback function that produces a dictionary. The callback works similar" |
| + " to computed dependency attributes: The function's parameter names are" |
| + " matched against the rule's attributes, so for example if you pass" |
| + " <code>outputs = _my_func</code> with the definition <code>def" |
| + " _my_func(srcs, deps): ...</code>, the function has access to the attributes" |
| + " <code>srcs</code> and <code>deps</code>. Whether the dictionary is" |
| + " specified directly or via a function, it is interpreted as follows.<p>Each" |
| + " entry in the dictionary creates a predeclared output where the key is an" |
| + " identifier and the value is a string template that determines the output's" |
| + " label. In the rule's implementation function, the identifier becomes the" |
| + " field name used to access the output's <a" |
| + " href='File.html'><code>File</code></a> in <a" |
| + " href='ctx.html#outputs'><code>ctx.outputs</code></a>. The output's label" |
| + " has the same package as the rule, and the part after the package is" |
| + " produced by substituting each placeholder of the form" |
| + " <code>\"%{ATTR}\"</code> with a string formed from the value of the" |
| + " attribute <code>ATTR</code>:<ul><li>String-typed attributes are substituted" |
| + " verbatim.<li>Label-typed attributes become the part of the label after the" |
| + " package, minus the file extension. For example, the label" |
| + " <code>\"//pkg:a/b.c\"</code> becomes <code>\"a/b\"</code>.<li>Output-typed" |
| + " attributes become the part of the label after the package, including the" |
| + " file extension (for the above example, <code>\"a/b.c\"</code>).<li>All" |
| + " list-typed attributes (for example, <code>attr.label_list</code>) used in" |
| + " placeholders are required to have <i>exactly one element</i>. Their" |
| + " conversion is the same as their non-list version" |
| + " (<code>attr.label</code>).<li>Other attribute types may not appear in" |
| + " placeholders.<li>The special non-attribute placeholders" |
| + " <code>%{dirname}</code> and <code>%{basename}</code> expand to those parts" |
| + " of the rule's label, excluding its package. For example, in" |
| + " <code>\"//pkg:a/b.c\"</code>, the dirname is <code>a</code> and the" |
| + " basename is <code>b.c</code>.</ul><p>In practice, the most common" |
| + " substitution placeholder is <code>\"%{name}\"</code>. For example, for a" |
| + " target named \"foo\", the outputs dict <code>{\"bin\":" |
| + " \"%{name}.exe\"}</code> predeclares an output named <code>foo.exe</code>" |
| + " that is accessible in the implementation function as" |
| + " <code>ctx.outputs.bin</code>."), |
| @Param( |
| name = "executable", |
| named = true, |
| defaultValue = "False", |
| doc = |
| "Whether this rule is considered executable, that is, whether it may be the subject" |
| + " of a <code>blaze run</code> command. See the <a" |
| + " href='https://bazel.build/rules/rules#executable_rules_and_test_rules'>" |
| + " Rules page</a> for more information."), |
| @Param( |
| name = "output_to_genfiles", |
| named = true, |
| defaultValue = "False", |
| doc = |
| "If true, the files will be generated in the genfiles directory instead of the " |
| + "bin directory. Unless you need it for compatibility with existing rules " |
| + "(e.g. when generating header files for C++), do not set this flag."), |
| @Param( |
| name = "fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the rule requires " |
| + "in target configuration."), |
| @Param( |
| name = "host_fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the rule requires " |
| + "in host configuration."), |
| @Param( |
| name = "_skylark_testable", |
| named = true, |
| defaultValue = "False", |
| doc = |
| "<i>(Experimental)</i><br/><br/>" |
| + "If true, this rule will expose its actions for inspection by rules that " |
| + "depend on it via an <a href=\"globals.html#Actions\">Actions</a> " |
| + "provider. The provider is also available to the rule itself by calling " |
| + "<a href=\"ctx.html#created_actions\">ctx.created_actions()</a>." |
| + "<br/><br/>" |
| + "This should only be used for testing the analysis-time behavior of " |
| + "Starlark rules. This flag may be removed in the future."), |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "If set, the set of toolchains this rule requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination. Toolchains" |
| + " will be found by checking the current platform, and provided to the rule" |
| + " implementation via <code>ctx.toolchain</code>."), |
| @Param( |
| name = "incompatible_use_toolchain_transition", |
| defaultValue = "False", |
| named = true, |
| doc = "Deprecated, this is no longer in use and should be removed."), |
| @Param( |
| name = "doc", |
| named = true, |
| defaultValue = "''", |
| doc = |
| "A description of the rule that can be extracted by documentation generating " |
| + "tools."), |
| @Param( |
| name = "provides", |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = PROVIDES_DOC), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "A list of constraints on the execution platform that apply to all targets of " |
| + "this rule type."), |
| @Param( |
| name = "analysis_test", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "If true, then this rule is treated as an analysis test. <p>Note: Analysis test" |
| + " rules are primarily defined using infrastructure provided in core Starlark" |
| + " libraries. See <a" |
| + " href=\"https://bazel.build/rules/testing#testing-rules\">Testing</a> for" |
| + " guidance. <p>If a rule is defined as an analysis test rule, it becomes" |
| + " allowed to use configuration transitions defined using <a" |
| + " href=\"#analysis_test_transition\">analysis_test_transition</a> on its" |
| + " attributes, but opts into some restrictions: <ul><li>Targets of this rule" |
| + " are limited in the number of transitive dependencies they may have. <li>The" |
| + " rule is considered a test rule (as if <code>test=True</code> were set)." |
| + " This supersedes the value of <code>test</code></li> <li>The rule" |
| + " implementation function may not register actions. Instead, it must register" |
| + " a pass/fail result via providing <a" |
| + " href='AnalysisTestResultInfo.html'>AnalysisTestResultInfo</a>.</li></ul>"), |
| @Param( |
| name = "build_setting", |
| allowedTypes = { |
| @ParamType(type = BuildSettingApi.class), |
| @ParamType(type = NoneType.class), |
| }, |
| defaultValue = "None", |
| named = true, |
| positional = false, |
| doc = |
| "If set, describes what kind of " |
| + "<a href = '${link config#user-defined-build-settings}'><code>build " |
| + "setting</code></a> this rule is. See the " |
| + "<a href='config.html'><code>config</code></a> module. If this is " |
| + "set, a mandatory attribute named \"build_setting_default\" is automatically " |
| + "added to this rule, with a type corresponding to the value passed in here."), |
| @Param( |
| name = "cfg", |
| defaultValue = "None", |
| named = true, |
| positional = false, |
| doc = |
| "If set, points to the configuration transition the rule will " |
| + "apply to its own configuration before analysis."), |
| @Param( |
| name = "exec_groups", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Dict of execution group name (string) to <a" |
| + " href='globals.html#exec_group'><code>exec_group</code>s</a>. If set," |
| + " allows rules to run actions on multiple execution platforms within a" |
| + " single target. See <a href='${link exec-groups}'>execution groups" |
| + " documentation</a> for more info."), |
| @Param( |
| name = "compile_one_filetype", |
| defaultValue = "None", |
| allowedTypes = { |
| @ParamType(type = Sequence.class, generic1 = String.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| positional = false, |
| doc = |
| "Used by --compile_one_dependency: if multiple rules consume the specified file, " |
| + "should we choose this rule over others."), |
| @Param( |
| name = "name", |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| allowedTypes = {@ParamType(type = String.class), @ParamType(type = NoneType.class)}, |
| disableWithFlag = BuildLanguageOptions.INCOMPATIBLE_REMOVE_RULE_NAME_PARAMETER, |
| valueWhenDisabled = "None", |
| doc = |
| "Deprecated: do not use.<p>The name of this rule, as understood by Bazel and" |
| + " reported in contexts such as logging," |
| + " <code>native.existing_rule(...)[kind]</code>, and <code>bazel query</code>." |
| + " Usually this is the same as the Starlark identifier that gets bound to this" |
| + " rule; for instance a rule called <code>foo_library</code> would typically" |
| + " be declared as <code>foo_library = rule(...)</code> and instantiated in a" |
| + " BUILD file as <code>foo_library(...)</code>.<p>If this parameter is" |
| + " omitted, the rule's name is set to the name of the first Starlark global" |
| + " variable to be bound to this rule within its declaring .bzl module. Thus," |
| + " <code>foo_library = rule(...)</code> need not specify this parameter if the" |
| + " name is <code>foo_library</code>.<p>Specifying an explicit name for a rule" |
| + " does not change where you are allowed to instantiate the rule."), |
| }, |
| useStarlarkThread = true) |
| StarlarkCallable rule( |
| StarlarkFunction implementation, |
| Boolean test, |
| Object attrs, |
| Object implicitOutputs, |
| Boolean executable, |
| Boolean outputToGenfiles, |
| Sequence<?> fragments, |
| Sequence<?> hostFragments, |
| Boolean starlarkTestable, |
| Sequence<?> toolchains, |
| boolean useToolchainTransition, |
| String doc, |
| Sequence<?> providesArg, |
| Sequence<?> execCompatibleWith, |
| Object analysisTest, |
| Object buildSetting, |
| Object cfg, |
| Object execGroups, |
| Object compileOneFiletype, |
| Object name, |
| StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "aspect", |
| doc = |
| "Creates a new aspect. The result of this function must be stored in a global value." |
| + " Please see the <a href=\"https://bazel.build/rules/aspects\">introduction to" |
| + " Aspects</a> for more details.", |
| parameters = { |
| @Param( |
| name = "implementation", |
| named = true, |
| doc = |
| "A Starlark function that implements this aspect, with exactly two parameters: " |
| + "<a href=\"Target.html\">Target</a> (the target to which the aspect is " |
| + "applied) and <a href=\"ctx.html\">ctx</a> (the rule context which the target" |
| + "is created from). Attributes of the target are available via the " |
| + "<code>ctx.rule</code> field. This function is evaluated during the " |
| + "analysis phase for each application of an aspect to a target."), |
| @Param( |
| name = "attr_aspects", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of attribute names. The aspect propagates along dependencies specified in " |
| + " the attributes of a target with these names. Common values here include " |
| + "<code>deps</code> and <code>exports</code>. The list can also contain a " |
| + "single string <code>\"*\"</code> to propagate along all dependencies of a " |
| + "target."), |
| @Param( |
| name = "attrs", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| doc = |
| "A dictionary declaring all the attributes of the aspect. It maps from an " |
| + "attribute name to an attribute object, like `attr.label` or `attr.string` " |
| + "(see <a href=\"attr.html\">attr</a> module). Aspect attributes are " |
| + "available to implementation function as fields of <code>ctx</code> " |
| + "parameter. " |
| + "" |
| + "<p>Implicit attributes starting with <code>_</code> must have default " |
| + "values, and have type <code>label</code> or <code>label_list</code>. " |
| + "" |
| + "<p>Explicit attributes must have type <code>string</code>, and must use " |
| + "the <code>values</code> restriction. Explicit attributes restrict the " |
| + "aspect to only be used with rules that have attributes of the same " |
| + "name, type, and valid values according to the restriction."), |
| @Param( |
| name = "required_providers", |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "This attribute allows the aspect to limit its propagation to only the targets " |
| + "whose rules advertise its required providers. The value must be a " |
| + "list containing either individual providers or lists of providers but not " |
| + "both. For example, <code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code> " |
| + "is a valid value while <code>[FooInfo, BarInfo, [BazInfo, QuxInfo]]</code> " |
| + "is not valid." |
| + "" |
| + "<p>An unnested list of providers will automatically be converted to a list " |
| + "containing one list of providers. That is, <code>[FooInfo, BarInfo]</code> " |
| + "will automatically be converted to <code>[[FooInfo, BarInfo]]</code>." |
| + "" |
| + "<p>To make some rule (e.g. <code>some_rule</code>) targets visible to an " |
| + "aspect, <code>some_rule</code> must advertise all providers from at least " |
| + "one of the required providers lists. For example, if the " |
| + "<code>required_providers</code> of an aspect are " |
| + "<code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code>, this aspect can " |
| + "only see <code>some_rule</code> targets if and only if " |
| + "<code>some_rule</code> provides <code>FooInfo</code> *or* " |
| + "<code>BarInfo</code> *or* both <code>BazInfo</code> *and* " |
| + "<code>QuxInfo</code>."), |
| @Param( |
| name = "required_aspect_providers", |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "This attribute allows this aspect to inspect other aspects. The value must be a " |
| + "list containing either individual providers or lists of providers but not " |
| + "both. For example, <code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code> " |
| + "is a valid value while <code>[FooInfo, BarInfo, [BazInfo, QuxInfo]]</code> " |
| + "is not valid." |
| + "" |
| + "<p>An unnested list of providers will automatically be converted to a list " |
| + "containing one list of providers. That is, " |
| + "<code>[FooInfo, BarInfo]</code> will automatically be converted to " |
| + "<code>[[FooInfo, BarInfo]]</code>. " |
| + "" |
| + "<p>To make another aspect (e.g. <code>other_aspect</code>) visible to this " |
| + "aspect, <code>other_aspect</code> must provide all providers from at least " |
| + "one of the lists. In the example of " |
| + "<code>[[FooInfo], [BarInfo], [BazInfo, QuxInfo]]</code>, this aspect can " |
| + "only see <code>other_aspect</code> if and only if <code>other_aspect</code> " |
| + "provides <code>FooInfo</code> *or* <code>BarInfo</code> *or* both " |
| + "<code>BazInfo</code> *and* <code>QuxInfo</code>."), |
| @Param(name = "provides", named = true, defaultValue = "[]", doc = PROVIDES_DOC), |
| @Param( |
| name = "requires", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = StarlarkAspectApi.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = "List of aspects required to be propagated before this aspect."), |
| @Param( |
| name = "fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the aspect requires " |
| + "in target configuration."), |
| @Param( |
| name = "host_fragments", |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "List of names of configuration fragments that the aspect requires " |
| + "in host configuration."), |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| defaultValue = "[]", |
| doc = |
| "If set, the set of toolchains this rule requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination. Toolchains" |
| + " will be found by checking the current platform, and provided to the rule" |
| + " implementation via <code>ctx.toolchain</code>."), |
| @Param( |
| name = "incompatible_use_toolchain_transition", |
| defaultValue = "False", |
| named = true, |
| doc = "Deprecated, this is no longer in use and should be removed."), |
| @Param( |
| name = "doc", |
| named = true, |
| defaultValue = "''", |
| doc = |
| "A description of the aspect that can be extracted by documentation generating " |
| + "tools."), |
| @Param( |
| name = "apply_to_generating_rules", |
| named = true, |
| positional = false, |
| defaultValue = "False", |
| doc = |
| "If true, the aspect will, when applied to an output file, instead apply to the " |
| + "output file's generating rule. " |
| + "<p>For example, suppose an aspect propagates transitively through attribute " |
| + "`deps` and it is applied to target `alpha`. Suppose `alpha` has " |
| + "`deps = [':beta_output']`, where `beta_output` is a declared output of " |
| + "a target `beta`. Suppose `beta` has a target `charlie` as one of its " |
| + "`deps`. If `apply_to_generating_rules=True` for the aspect, then the aspect " |
| + "will propagate through `alpha`, `beta`, and `charlie`. If False, then the " |
| + "aspect will propagate only to `alpha`. </p><p>False by default.</p>"), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "A list of constraints on the execution platform that apply to all instances of" |
| + " this aspect."), |
| @Param( |
| name = "exec_groups", |
| allowedTypes = { |
| @ParamType(type = Dict.class), |
| @ParamType(type = NoneType.class), |
| }, |
| named = true, |
| defaultValue = "None", |
| positional = false, |
| doc = |
| "Dict of execution group name (string) to <a" |
| + " href='globals.html#exec_group'><code>exec_group</code>s</a>. If set," |
| + " allows aspects to run actions on multiple execution platforms within a" |
| + " single instance. See <a href='${link exec-groups}'>execution groups" |
| + " documentation</a> for more info.") |
| }, |
| useStarlarkThread = true) |
| StarlarkAspectApi aspect( |
| StarlarkFunction implementation, |
| Sequence<?> attributeAspects, |
| Object attrs, |
| Sequence<?> requiredProvidersArg, |
| Sequence<?> requiredAspectProvidersArg, |
| Sequence<?> providesArg, |
| Sequence<?> requiredAspects, |
| Sequence<?> fragments, |
| Sequence<?> hostFragments, |
| Sequence<?> toolchains, |
| boolean useToolchainTransition, |
| String doc, |
| Boolean applyToGeneratingRules, |
| Sequence<?> execCompatibleWith, |
| Object execGroups, |
| StarlarkThread thread) |
| throws EvalException; |
| |
| @StarlarkMethod( |
| name = "Label", |
| doc = |
| "Converts a label string into a <code>Label</code> object, in the context of the package" |
| + " where the calling <code>.bzl</code> source file lives. If the given value is" |
| + " already a <code>Label</code>, it is returned unchanged." |
| + "<p>For macros, a related function," |
| + " <code><a" |
| + " href='native#package_relative_label'>native.package_relative_label()</a></code>," |
| + " converts the input into a <code>Label</code> in the context of the package" |
| + " currently being constructed. Use that function to mimic the string-to-label" |
| + " conversion that is automatically done by label-valued rule attributes.", |
| parameters = { |
| @Param( |
| name = "input", |
| allowedTypes = {@ParamType(type = String.class), @ParamType(type = Label.class)}, |
| doc = |
| "The input label string or Label object. If a Label object is passed, it's" |
| + " returned as is.") |
| }, |
| useStarlarkThread = true) |
| @StarlarkConstructor |
| Label label(Object input, StarlarkThread thread) throws EvalException; |
| |
| @StarlarkMethod( |
| name = "exec_group", |
| doc = |
| "Creates an <a href='${link exec-groups}'>execution group</a> which can be used to" |
| + " create actions for a specific execution platform during rule implementation.", |
| parameters = { |
| @Param( |
| name = TOOLCHAINS_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = Object.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = |
| "The set of toolchains this execution group requires. The list can contain String," |
| + " Label, or StarlarkToolchainTypeApi objects, in any combination."), |
| @Param( |
| name = EXEC_COMPATIBLE_WITH_PARAM, |
| allowedTypes = {@ParamType(type = Sequence.class, generic1 = String.class)}, |
| named = true, |
| positional = false, |
| defaultValue = "[]", |
| doc = "A list of constraints on the execution platform."), |
| @Param( |
| name = "copy_from_rule", |
| defaultValue = "False", |
| named = true, |
| positional = false, |
| doc = |
| "If set to true, this exec group inherits the toolchains and constraints of the" |
| + " rule to which this group is attached. If set to any other string this will" |
| + " throw an error.") |
| }, |
| useStarlarkThread = true) |
| ExecGroupApi execGroup( |
| Sequence<?> execCompatibleWith, |
| Sequence<?> toolchains, |
| Boolean copyFromRule, |
| StarlarkThread thread) |
| throws EvalException; |
| } |
