| // 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.skylarkbuildapi; | |
| import com.google.devtools.build.lib.cmdline.Label; | |
| import com.google.devtools.build.lib.events.Location; | |
| import com.google.devtools.build.lib.skylarkbuildapi.StarlarkConfigApi.BuildSettingApi; | |
| import com.google.devtools.build.lib.skylarkinterface.Param; | |
| import com.google.devtools.build.lib.skylarkinterface.ParamType; | |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable; | |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkConstructor; | |
| import com.google.devtools.build.lib.skylarkinterface.SkylarkGlobalLibrary; | |
| import com.google.devtools.build.lib.syntax.BaseFunction; | |
| import com.google.devtools.build.lib.syntax.EvalException; | |
| import com.google.devtools.build.lib.syntax.FuncallExpression; | |
| import com.google.devtools.build.lib.syntax.Runtime.NoneType; | |
| import com.google.devtools.build.lib.syntax.SkylarkDict; | |
| import com.google.devtools.build.lib.syntax.SkylarkList; | |
| import com.google.devtools.build.lib.syntax.StarlarkFunction; | |
| import com.google.devtools.build.lib.syntax.StarlarkSemantics.FlagIdentifier; | |
| import com.google.devtools.build.lib.syntax.StarlarkThread; | |
| /** | |
| * Interface for a global Skylark library containing rule-related helper and registration functions. | |
| */ | |
| @SkylarkGlobalLibrary | |
| public interface SkylarkRuleFunctionsApi<FileApiT extends FileApi> { | |
| static final 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."; | |
| @SkylarkCallable( | |
| name = "provider", | |
| doc = | |
| "Creates a declared provider 'constructor'. The return value of this " | |
| + "function can be used to create \"struct-like\" values. Example:<br>" | |
| + "<pre class=\"language-python\">data = provider()\n" | |
| + "d = data(x = 2, y = 3)\n" | |
| + "print(d.x + d.y) # prints 5</pre>", | |
| parameters = { | |
| @Param( | |
| name = "doc", | |
| type = String.class, | |
| 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 = SkylarkList.class, generic1 = String.class), | |
| @ParamType(type = SkylarkDict.class) | |
| }, | |
| noneable = true, | |
| named = true, | |
| positional = false, | |
| defaultValue = "None") | |
| }, | |
| useLocation = true) | |
| public ProviderApi provider(String doc, Object fields, Location location) throws EvalException; | |
| @SkylarkCallable( | |
| 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", | |
| type = StarlarkFunction.class, | |
| 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", | |
| type = Boolean.class, | |
| 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='../rules.$DOC_EXT#executable-rules-and-test-rules'>Rules page</a> " | |
| + "for more information."), | |
| @Param( | |
| name = "attrs", | |
| type = SkylarkDict.class, | |
| named = true, | |
| noneable = true, | |
| defaultValue = "None", | |
| doc = | |
| "dictionary to declare all the attributes of the rule. It maps from an attribute " | |
| + "name to an attribute object (see <a href=\"attr.html\">attr</a> module). " | |
| + "Attributes starting with <code>_</code> are private, and can be used to " | |
| + "add an implicit dependency on a label. The attribute <code>name</code> is " | |
| + "implicitly added and must not be specified. Attributes " | |
| + "<code>visibility</code>, <code>deprecation</code>, <code>tags</code>, " | |
| + "<code>testonly</code>, and <code>features</code> are implicitly added and " | |
| + "cannot be overridden."), | |
| // TODO(bazel-team): need to give the types of these builtin attributes | |
| @Param( | |
| name = "outputs", | |
| allowedTypes = { | |
| @ParamType(type = SkylarkDict.class), | |
| @ParamType(type = NoneType.class), | |
| @ParamType(type = StarlarkFunction.class) // a function defined in Starlark | |
| }, | |
| named = true, | |
| callbackEnabled = true, | |
| noneable = true, | |
| defaultValue = "None", | |
| valueWhenDisabled = "None", | |
| disableWithFlag = FlagIdentifier.INCOMPATIBLE_NO_RULE_OUTPUTS_PARAM, | |
| doc = | |
| "This parameter has been deprecated. Migrate rules to use" | |
| + " <code>OutputGroupInfo</code> or <code>attr.output</code> instead. <p>A" | |
| + " schema for defining predeclared outputs. Unlike <a" | |
| + " href='attr.html#output'><code>output</code></a> and <a" | |
| + " href='attr.html#output_list'><code>output_list</code></a> attributes, the" | |
| + " user does not specify the labels for these files. See the <a" | |
| + " href='../rules.$DOC_EXT#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", | |
| type = Boolean.class, | |
| 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='../rules.$DOC_EXT#executable-rules-and-test-rules'>Rules page</a> " | |
| + "for more information."), | |
| @Param( | |
| name = "output_to_genfiles", | |
| type = Boolean.class, | |
| 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", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "List of names of configuration fragments that the rule requires " | |
| + "in target configuration."), | |
| @Param( | |
| name = "host_fragments", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "List of names of configuration fragments that the rule requires " | |
| + "in host configuration."), | |
| @Param( | |
| name = "_skylark_testable", | |
| type = Boolean.class, | |
| 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", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "<i>(Experimental)</i><br/><br/>" | |
| + "If set, the set of toolchains this rule requires. Toolchains will be " | |
| + "found by checking the current platform, and provided to the rule " | |
| + "implementation via <code>ctx.toolchain</code>."), | |
| @Param( | |
| name = "doc", | |
| type = String.class, | |
| named = true, | |
| defaultValue = "''", | |
| doc = | |
| "A description of the rule that can be extracted by documentation generating " | |
| + "tools."), | |
| @Param( | |
| name = "provides", | |
| type = SkylarkList.class, | |
| named = true, | |
| positional = false, | |
| defaultValue = "[]", | |
| doc = PROVIDES_DOC), | |
| @Param( | |
| name = "exec_compatible_with", | |
| type = SkylarkList.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", | |
| allowedTypes = { | |
| @ParamType(type = Boolean.class), | |
| }, | |
| 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=\"../testing.html#for-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 supercedes 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", | |
| type = BuildSettingApi.class, | |
| noneable = true, | |
| defaultValue = "None", | |
| named = true, | |
| positional = false, | |
| enableOnlyWithFlag = FlagIdentifier.EXPERIMENTAL_BUILD_SETTING_API, | |
| valueWhenDisabled = "None", | |
| doc = | |
| "If set, describes what kind of " | |
| + "<a href = '../config.$DOC_EXT#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", | |
| type = Object.class, | |
| noneable = true, | |
| defaultValue = "None", | |
| named = true, | |
| positional = false, | |
| doc = | |
| "If set, points to the configuration transition the rule will " | |
| + "apply to its own configuration before analysis.") | |
| }, | |
| useAst = true, | |
| useStarlarkThread = true) | |
| public BaseFunction rule( | |
| StarlarkFunction implementation, | |
| Boolean test, | |
| Object attrs, | |
| Object implicitOutputs, | |
| Boolean executable, | |
| Boolean outputToGenfiles, | |
| SkylarkList<?> fragments, | |
| SkylarkList<?> hostFragments, | |
| Boolean skylarkTestable, | |
| SkylarkList<?> toolchains, | |
| String doc, | |
| SkylarkList<?> providesArg, | |
| SkylarkList<?> execCompatibleWith, | |
| Object analysisTest, | |
| Object buildSetting, | |
| Object cfg, | |
| FuncallExpression ast, | |
| StarlarkThread thread) | |
| throws EvalException; | |
| @SkylarkCallable( | |
| name = "aspect", | |
| doc = | |
| "Creates a new aspect. The result of this function must be stored in a global value. " | |
| + "Please see the <a href=\"../aspects.md\">introduction to Aspects</a> for more " | |
| + "details.", | |
| parameters = { | |
| @Param( | |
| name = "implementation", | |
| type = StarlarkFunction.class, | |
| 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", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| 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", | |
| type = SkylarkDict.class, | |
| named = true, | |
| noneable = 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_aspect_providers", | |
| type = SkylarkList.class, | |
| named = true, | |
| defaultValue = "[]", | |
| doc = | |
| "This attribute allows this aspect to inspect other aspects. The value must be a " | |
| + "list of providers, or a list of lists of providers. For example, " | |
| + "<code>[FooInfo, BarInfo, [BazInfo, QuxInfo]]</code> is a " | |
| + "valid value." | |
| + "" | |
| + "<p>A single 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", | |
| type = SkylarkList.class, | |
| named = true, | |
| defaultValue = "[]", | |
| doc = PROVIDES_DOC), | |
| @Param( | |
| name = "fragments", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "List of names of configuration fragments that the aspect requires " | |
| + "in target configuration."), | |
| @Param( | |
| name = "host_fragments", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "List of names of configuration fragments that the aspect requires " | |
| + "in host configuration."), | |
| @Param( | |
| name = "toolchains", | |
| type = SkylarkList.class, | |
| named = true, | |
| generic1 = String.class, | |
| defaultValue = "[]", | |
| doc = | |
| "<i>(Experimental)</i><br/><br/>" | |
| + "If set, the set of toolchains this rule requires. Toolchains will be " | |
| + "found by checking the current platform, and provided to the rule " | |
| + "implementation via <code>ctx.toolchain</code>."), | |
| @Param( | |
| name = "doc", | |
| type = String.class, | |
| named = true, | |
| defaultValue = "''", | |
| doc = | |
| "A description of the aspect that can be extracted by documentation generating " | |
| + "tools."), | |
| @Param( | |
| name = "apply_to_generating_rules", | |
| type = Boolean.class, | |
| named = true, | |
| positional = false, | |
| defaultValue = "False", | |
| enableOnlyWithFlag = FlagIdentifier.EXPERIMENTAL_ASPECT_OUTPUT_PROPAGATION, | |
| valueWhenDisabled = "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>") | |
| }, | |
| useStarlarkThread = true, | |
| useAst = true) | |
| public SkylarkAspectApi aspect( | |
| StarlarkFunction implementation, | |
| SkylarkList<?> attributeAspects, | |
| Object attrs, | |
| SkylarkList<?> requiredAspectProvidersArg, | |
| SkylarkList<?> providesArg, | |
| SkylarkList<?> fragments, | |
| SkylarkList<?> hostFragments, | |
| SkylarkList<?> toolchains, | |
| String doc, | |
| Boolean applyToGeneratingRules, | |
| FuncallExpression ast, | |
| StarlarkThread thread) | |
| throws EvalException; | |
| @SkylarkCallable( | |
| name = "Label", | |
| doc = | |
| "Creates a Label referring to a BUILD target. Use " | |
| + "this function only when you want to give a default value for the label " | |
| + "attributes. The argument must refer to an absolute label. " | |
| + "Example: <br><pre class=language-python>Label(\"//tools:default\")</pre>", | |
| parameters = { | |
| @Param( | |
| name = "label_string", | |
| type = String.class, | |
| legacyNamed = true, | |
| doc = "the label string."), | |
| @Param( | |
| name = "relative_to_caller_repository", | |
| type = Boolean.class, | |
| defaultValue = "False", | |
| named = true, | |
| positional = false, | |
| doc = | |
| "Deprecated. Do not use. " | |
| + "When relative_to_caller_repository is True and the calling thread is a " | |
| + "rule's implementation function, then a repo-relative label //foo:bar is " | |
| + "resolved relative to the rule's repository. For calls to Label from any " | |
| + "other thread, or calls in which the relative_to_caller_repository flag is " | |
| + "False, a repo-relative label is resolved relative to the file in which the " | |
| + "Label() call appears.") | |
| }, | |
| useLocation = true, | |
| useStarlarkThread = true) | |
| @SkylarkConstructor(objectType = Label.class) | |
| public Label label( | |
| String labelString, Boolean relativeToCallerRepository, Location loc, StarlarkThread thread) | |
| throws EvalException; | |
| } |