| // 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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.$DOC_EXT#executable-rules-and-test-rules'>Rules page</a> " |
| + "for more information."), |
| @Param( |
| name = "attrs", |
| type = SkylarkDict.class, |
| legacyNamed = true, |
| noneable = true, |
| defaultValue = "None", |
| doc = |
| "dictionary to declare all the attributes of the rule. It maps from an attribute " |
| + "name to an attribute object (see <a href=\"attr.html\">attr</a> module). " |
| + "Attributes starting with <code>_</code> are private, and can be used to " |
| + "add an implicit dependency on a label. The attribute <code>name</code> is " |
| + "implicitly added and must not be specified. Attributes " |
| + "<code>visibility</code>, <code>deprecation</code>, <code>tags</code>, " |
| + "<code>testonly</code>, and <code>features</code> are implicitly added and " |
| + "cannot be overridden."), |
| // TODO(bazel-team): need to give the types of these builtin attributes |
| @Param( |
| name = "outputs", |
| allowedTypes = { |
| @ParamType(type = SkylarkDict.class), |
| @ParamType(type = NoneType.class), |
| @ParamType(type = BaseFunction.class) |
| }, |
| legacyNamed = true, |
| callbackEnabled = true, |
| noneable = true, |
| defaultValue = "None", |
| doc = |
| "<b>Experimental:</b> This API is in the process of being redesigned." |
| + "<p>A schema for defining predeclared outputs. Unlike " |
| + "<a href='attr.html#output'><code>output</code></a> and " |
| + "<a href='attr.html#output_list'><code>output_list</code></a> attributes, " |
| + "the user does not specify the labels for these files. " |
| + "See the <a href='../rules.$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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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 = "False", |
| 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>."), |
| @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", |
| // TODO(juliexxia): Link to in-build testing documentation when it is available. |
| doc = |
| "If set, describes what kind of build setting 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = true, |
| defaultValue = "[]", |
| doc = PROVIDES_DOC |
| ), |
| @Param( |
| name = "fragments", |
| type = SkylarkList.class, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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, |
| legacyNamed = 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; |
| |
| @SkylarkCallable( |
| name = "FileType", |
| doc = |
| "Deprecated. Creates a file filter from a list of strings. For example, to match " |
| + "files ending with .cc or .cpp, use: " |
| + "<pre class=language-python>FileType([\".cc\", \".cpp\"])</pre>", |
| parameters = { |
| @Param( |
| name = "types", |
| type = SkylarkList.class, |
| legacyNamed = true, |
| generic1 = String.class, |
| defaultValue = "[]", |
| doc = "a list of the accepted file extensions." |
| ) |
| }, |
| useLocation = true, |
| useEnvironment = true |
| ) |
| @SkylarkConstructor(objectType = FileTypeApi.class) |
| public FileTypeApi<FileApiT> fileType(SkylarkList<?> types, Location loc, Environment env) |
| throws EvalException; |
| } |
