| // 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.skylarkinterface.StarlarkContext; | |
| import com.google.devtools.build.lib.syntax.BaseFunction; | |
| import com.google.devtools.build.lib.syntax.Environment; | |
| 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.Runtime.UnboundMarker; | |
| import com.google.devtools.build.lib.syntax.SkylarkDict; | |
| import com.google.devtools.build.lib.syntax.SkylarkList; | |
| import com.google.devtools.build.lib.syntax.StarlarkSemantics.FlagIdentifier; | |
| /** | |
| * 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 = BaseFunction.class, | |
| named = true, | |
| doc = | |
| "the 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.$DOC_EXT#executable-rules-and-test-rules'>Rules page</a> " | |
| + "for more information."), | |
| @Param( | |
| name = "attrs", | |
| type = SkylarkDict.class, | |
| named = true, | |
| noneable = true, | |
| defaultValue = "None", | |
| doc = | |
| "dictionary to declare all the attributes of the rule. It maps from an attribute " | |
| + "name to an attribute object (see <a href=\"attr.html\">attr</a> module). " | |
| + "Attributes starting with <code>_</code> are private, and can be used to " | |
| + "add an implicit dependency on a label. The attribute <code>name</code> is " | |
| + "implicitly added and must not be specified. Attributes " | |
| + "<code>visibility</code>, <code>deprecation</code>, <code>tags</code>, " | |
| + "<code>testonly</code>, and <code>features</code> are implicitly added and " | |
| + "cannot be overridden."), | |
| // TODO(bazel-team): need to give the types of these builtin attributes | |
| @Param( | |
| name = "outputs", | |
| allowedTypes = { | |
| @ParamType(type = SkylarkDict.class), | |
| @ParamType(type = NoneType.class), | |
| @ParamType(type = BaseFunction.class) | |
| }, | |
| named = true, | |
| callbackEnabled = true, | |
| noneable = true, | |
| defaultValue = "None", | |
| valueWhenDisabled = "None", | |
| disableWithFlag = FlagIdentifier.INCOMPATIBLE_NO_RULE_OUTPUTS_PARAM, | |
| doc = | |
| "A schema for defining predeclared outputs. Unlike " | |
| + "<a href='attr.html#output'><code>output</code></a> and " | |
| + "<a href='attr.html#output_list'><code>output_list</code></a> attributes, " | |
| + "the user does not specify the labels for these files. " | |
| + "See the <a href='../rules.$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 = "execution_platform_constraints_allowed", | |
| type = Boolean.class, | |
| named = true, | |
| positional = false, | |
| defaultValue = "True", | |
| disableWithFlag = | |
| FlagIdentifier.INCOMPATIBLE_DISALLOW_RULE_EXECUTION_PLATFORM_CONSTRAINTS_ALLOWED, | |
| valueWhenDisabled = "True", | |
| doc = | |
| "If true, a special attribute named <code>exec_compatible_with</code> of " | |
| + "label-list type is added, which must not already exist in " | |
| + "<code>attrs</code>. Targets may use this attribute to specify additional " | |
| + "constraints on the execution platform beyond those given in the " | |
| + "<code>exec_compatible_with</code> argument to <code>rule()</code>. " | |
| + "This will be deprecated and removed in the near future, and all rules will " | |
| + "be able to use <code>exec_compatible_with</code>."), | |
| @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), | |
| @ParamType(type = UnboundMarker.class) | |
| }, | |
| named = true, | |
| positional = false, | |
| // TODO(cparsons): Make the default false when this is no longer experimental. | |
| defaultValue = "unbound", | |
| // TODO(cparsons): Link to in-build testing documentation when it is available. | |
| doc = | |
| "<b>Experimental: This parameter is experimental and subject to change at any " | |
| + "time.</b><p> If true, then this rule is treated as an analysis test."), | |
| @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, | |
| useEnvironment = true, | |
| useContext = true) | |
| public BaseFunction rule( | |
| BaseFunction implementation, | |
| Boolean test, | |
| Object attrs, | |
| Object implicitOutputs, | |
| Boolean executable, | |
| Boolean outputToGenfiles, | |
| SkylarkList<?> fragments, | |
| SkylarkList<?> hostFragments, | |
| Boolean skylarkTestable, | |
| SkylarkList<?> toolchains, | |
| String doc, | |
| SkylarkList<?> providesArg, | |
| Boolean executionPlatformConstraintsAllowed, | |
| SkylarkList<?> execCompatibleWith, | |
| Object analysisTest, | |
| Object buildSetting, | |
| Object cfg, | |
| FuncallExpression ast, | |
| Environment funcallEnv, | |
| StarlarkContext context) | |
| 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 = BaseFunction.class, | |
| named = true, | |
| doc = | |
| "the function implementing this aspect. Must have two parameters: " | |
| + "<a href=\"Target.html\">Target</a> (the target to which the aspect is " | |
| + "applied) and <a href=\"ctx.html\">ctx</a>. Attributes of the target are " | |
| + "available via ctx.rule field. The function is called 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 by" | |
| + " attributes of a target with this name. The list can also contain a single " | |
| + "string '*': in that case aspect propagates along all dependencies of a" | |
| + " target."), | |
| @Param( | |
| name = "attrs", | |
| type = SkylarkDict.class, | |
| named = true, | |
| noneable = true, | |
| defaultValue = "None", | |
| doc = | |
| "dictionary to declare all the attributes of the aspect. It maps from an" | |
| + " attribute name to an attribute object (see <a href=\"attr.html\">attr</a>" | |
| + " module). Aspect attributes are available to implementation function as" | |
| + " fields of ctx parameter. Implicit attributes starting with <code>_</code>" | |
| + " must have default values, and have type <code>label</code> or" | |
| + " <code>label_list</code>. Explicit attributes must have type" | |
| + " <code>string</code>, and must use the <code>values</code> restriction. If" | |
| + " explicit attributes are present, the aspect can only be used with rules" | |
| + " that have attributes of the same name and type, with valid values."), | |
| @Param( | |
| name = "required_aspect_providers", | |
| type = SkylarkList.class, | |
| named = true, | |
| defaultValue = "[]", | |
| doc = | |
| "Allow the aspect to inspect other aspects. If the aspect propagates along a" | |
| + " dependency, and the underlying rule sends a different aspect along that " | |
| + "dependency, and that aspect provides one of the providers listed here, this" | |
| + " aspect will see the providers provided by that aspect. <p>The value should" | |
| + " be either a list of providers, or a list of lists of providers. This" | |
| + " aspect will 'see' the underlying aspects that provide ALL providers from" | |
| + " at least ONE of these lists. A single list of providers will be" | |
| + " automatically converted to a list containing one list of providers."), | |
| @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.") | |
| }, | |
| useEnvironment = true, | |
| useAst = true) | |
| public SkylarkAspectApi aspect( | |
| BaseFunction implementation, | |
| SkylarkList<?> attributeAspects, | |
| Object attrs, | |
| SkylarkList<?> requiredAspectProvidersArg, | |
| SkylarkList<?> providesArg, | |
| SkylarkList<?> fragments, | |
| SkylarkList<?> hostFragments, | |
| SkylarkList<?> toolchains, | |
| String doc, | |
| FuncallExpression ast, | |
| Environment funcallEnv) | |
| 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, | |
| useEnvironment = true, | |
| useContext = true) | |
| @SkylarkConstructor(objectType = Label.class) | |
| public Label label( | |
| String labelString, | |
| Boolean relativeToCallerRepository, | |
| Location loc, | |
| Environment env, | |
| StarlarkContext context) | |
| throws EvalException; | |
| } |