// Copyright 2014 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.rules; import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.DATA; import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.HOST; import static com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition.NONE; import static com.google.devtools.build.lib.packages.Attribute.attr; import static com.google.devtools.build.lib.packages.BuildType.LABEL; import static com.google.devtools.build.lib.packages.BuildType.LABEL_LIST; import static com.google.devtools.build.lib.packages.BuildType.LICENSE; import static com.google.devtools.build.lib.syntax.SkylarkType.castList; import static com.google.devtools.build.lib.syntax.SkylarkType.castMap; import static com.google.devtools.build.lib.syntax.Type.BOOLEAN; import static com.google.devtools.build.lib.syntax.Type.INTEGER; import static com.google.devtools.build.lib.syntax.Type.STRING; import static com.google.devtools.build.lib.syntax.Type.STRING_LIST; import com.google.common.annotations.VisibleForTesting; import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheLoader; import com.google.common.cache.LoadingCache; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.devtools.build.lib.Constants; import com.google.devtools.build.lib.analysis.BaseRuleClasses; import com.google.devtools.build.lib.analysis.config.BuildConfiguration; import com.google.devtools.build.lib.analysis.config.RunUnder; import com.google.devtools.build.lib.cmdline.Label; import com.google.devtools.build.lib.cmdline.LabelSyntaxException; import com.google.devtools.build.lib.events.Location; import com.google.devtools.build.lib.packages.Attribute; import com.google.devtools.build.lib.packages.Attribute.ConfigurationTransition; import com.google.devtools.build.lib.packages.Attribute.LateBoundLabel; import com.google.devtools.build.lib.packages.AttributeMap; import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SkylarkImplicitOutputsFunctionWithCallback; import com.google.devtools.build.lib.packages.ImplicitOutputsFunction.SkylarkImplicitOutputsFunctionWithMap; import com.google.devtools.build.lib.packages.Package.NameConflictException; import com.google.devtools.build.lib.packages.PackageFactory; import com.google.devtools.build.lib.packages.PackageFactory.PackageContext; import com.google.devtools.build.lib.packages.Rule; import com.google.devtools.build.lib.packages.RuleClass; import com.google.devtools.build.lib.packages.RuleClass.Builder; import com.google.devtools.build.lib.packages.RuleClass.Builder.RuleClassType; import com.google.devtools.build.lib.packages.RuleFactory; import com.google.devtools.build.lib.packages.RuleFactory.InvalidRuleException; import com.google.devtools.build.lib.packages.TargetUtils; import com.google.devtools.build.lib.packages.TestSize; import com.google.devtools.build.lib.syntax.BaseFunction; import com.google.devtools.build.lib.syntax.BuiltinFunction; import com.google.devtools.build.lib.syntax.ClassObject; import com.google.devtools.build.lib.syntax.ClassObject.SkylarkClassObject; import com.google.devtools.build.lib.syntax.Environment; import com.google.devtools.build.lib.syntax.Environment.NoSuchVariableException; import com.google.devtools.build.lib.syntax.EvalException; import com.google.devtools.build.lib.syntax.EvalUtils; import com.google.devtools.build.lib.syntax.FuncallExpression; import com.google.devtools.build.lib.syntax.FunctionSignature; import com.google.devtools.build.lib.syntax.Runtime; import com.google.devtools.build.lib.syntax.SkylarkCallbackFunction; import com.google.devtools.build.lib.syntax.SkylarkList; import com.google.devtools.build.lib.syntax.SkylarkModuleNameResolver; import com.google.devtools.build.lib.syntax.SkylarkSignature; import com.google.devtools.build.lib.syntax.SkylarkSignature.Param; import com.google.devtools.build.lib.syntax.SkylarkSignatureProcessor; import com.google.devtools.build.lib.syntax.Type; import com.google.devtools.build.lib.syntax.Type.ConversionException; import com.google.devtools.build.lib.vfs.PathFragment; import java.util.HashMap; import java.util.Map; import java.util.concurrent.ExecutionException; /** * A helper class to provide an easier API for Skylark rule definitions. */ public class SkylarkRuleClassFunctions { //TODO(bazel-team): proper enum support @SkylarkSignature(name = "DATA_CFG", returnType = ConfigurationTransition.class, doc = "Experimental. Specifies a transition to the data configuration.") private static final Object dataTransition = ConfigurationTransition.DATA; @SkylarkSignature(name = "HOST_CFG", returnType = ConfigurationTransition.class, doc = "Specifies a transition to the host configuration.") private static final Object hostTransition = ConfigurationTransition.HOST; private static final LateBoundLabel RUN_UNDER = new LateBoundLabel() { @Override public Label getDefault(Rule rule, BuildConfiguration configuration) { RunUnder runUnder = configuration.getRunUnder(); return runUnder == null ? null : runUnder.getLabel(); } }; // TODO(bazel-team): Copied from ConfiguredRuleClassProvider for the transition from built-in // rules to skylark extensions. Using the same instance would require a large refactoring. // If we don't want to support old built-in rules and Skylark simultaneously // (except for transition phase) it's probably OK. private static LoadingCache labelCache = CacheBuilder.newBuilder().build(new CacheLoader() { @Override public Label load(String from) throws Exception { try { return Label.parseAbsolute(from); } catch (LabelSyntaxException e) { throw new Exception(from); } } }); // TODO(bazel-team): Remove the code duplication (BaseRuleClasses and this class). /** Parent rule class for non-executable non-test Skylark rules. */ public static final RuleClass baseRule = BaseRuleClasses.commonCoreAndSkylarkAttributes( new RuleClass.Builder("$base_rule", RuleClassType.ABSTRACT, true)) .add(attr("expect_failure", STRING)) .build(); /** Parent rule class for executable non-test Skylark rules. */ public static final RuleClass binaryBaseRule = new RuleClass.Builder("$binary_base_rule", RuleClassType.ABSTRACT, true, baseRule) .add( attr("args", STRING_LIST) .nonconfigurable("policy decision: should be consistent across configurations")) .add(attr("output_licenses", LICENSE)) .build(); /** Parent rule class for test Skylark rules. */ public static final RuleClass testBaseRule = new RuleClass.Builder("$test_base_rule", RuleClassType.ABSTRACT, true, baseRule) .add(attr("size", STRING).value("medium").taggable() .nonconfigurable("used in loading phase rule validation logic")) .add(attr("timeout", STRING).taggable() .nonconfigurable("used in loading phase rule validation logic").value( new Attribute.ComputedDefault() { @Override public Object getDefault(AttributeMap rule) { TestSize size = TestSize.getTestSize(rule.get("size", Type.STRING)); if (size != null) { String timeout = size.getDefaultTimeout().toString(); if (timeout != null) { return timeout; } } return "illegal"; } })) .add(attr("flaky", BOOLEAN).value(false).taggable() .nonconfigurable("taggable - called in Rule.getRuleTags")) .add(attr("shard_count", INTEGER).value(-1)) .add(attr("local", BOOLEAN).value(false).taggable() .nonconfigurable("policy decision: this should be consistent across configurations")) .add(attr("args", STRING_LIST) .nonconfigurable("policy decision: should be consistent across configurations")) .add(attr("$test_runtime", LABEL_LIST).cfg(HOST).value(ImmutableList.of( labelCache.getUnchecked(Constants.TOOLS_REPOSITORY + "//tools/test:runtime")))) .add(attr(":run_under", LABEL).cfg(DATA).value(RUN_UNDER)) .build(); /** * In native code, private values start with $. * In Skylark, private values start with _, because of the grammar. */ private static String attributeToNative(String oldName, Location loc, boolean isLateBound) throws EvalException { if (oldName.isEmpty()) { throw new EvalException(loc, "Attribute name cannot be empty"); } if (isLateBound) { if (oldName.charAt(0) != '_') { throw new EvalException(loc, "When an attribute value is a function, " + "the attribute must be private (start with '_')"); } return ":" + oldName.substring(1); } if (oldName.charAt(0) == '_') { return "$" + oldName.substring(1); } return oldName; } // TODO(bazel-team): implement attribute copy and other rule properties @SkylarkSignature(name = "rule", doc = "Creates a new rule. Store it in a global value, so that it can be loaded and called " + "from BUILD files.", returnType = BaseFunction.class, mandatoryPositionals = { @Param(name = "implementation", type = BaseFunction.class, doc = "the function implementing this rule, must have exactly one parameter: " + "ctx. 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.") }, optionalPositionals = { @Param(name = "test", type = Boolean.class, defaultValue = "False", doc = "Whether this rule is a test rule. " + "If True, the rule must end with _test (otherwise it must not), " + "and there must be an action that generates ctx.outputs.executable."), @Param(name = "attrs", type = Map.class, 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 attr module). " + "Attributes starting with _ are private, and can be used to add " + "an implicit dependency on a label. The attribute name is implicitly " + "added and must not be specified. Attributes visibility, " + "deprecation, tags, testonly, and " + "features are implicitly added and might be overriden."), // TODO(bazel-team): need to give the types of these builtin attributes @Param(name = "outputs", type = Map.class, callbackEnabled = true, noneable = true, defaultValue = "None", doc = "outputs of this rule. " + "It is a dictionary mapping from string to a template name. " + "For example: {\"ext\": \"%{name}.ext\"}.
" + "The dictionary key becomes an attribute in ctx.outputs. " // TODO(bazel-team): Make doc more clear, wrt late-bound attributes. + "It may also be a function (which receives ctx.attr as argument) " + "returning such a dictionary."), @Param(name = "executable", type = Boolean.class, defaultValue = "False", doc = "whether this rule is marked as executable or not. If True, " + "there must be an action that generates ctx.outputs.executable."), @Param(name = "output_to_genfiles", type = Boolean.class, 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, 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, generic1 = String.class, defaultValue = "[]", doc = "List of names of configuration fragments that the rule requires " + "in host configuration.")}, useAst = true, useEnvironment = true) private static final BuiltinFunction rule = new BuiltinFunction("rule") { @SuppressWarnings({"rawtypes", "unchecked"}) // castMap produces // an Attribute.Builder instead of a Attribute.Builder but it's OK. public BaseFunction invoke(BaseFunction implementation, Boolean test, Object attrs, Object implicitOutputs, Boolean executable, Boolean outputToGenfiles, SkylarkList fragments, SkylarkList hostFragments, FuncallExpression ast, Environment funcallEnv) throws EvalException, ConversionException { funcallEnv.checkLoadingPhase("rule", ast.getLocation()); RuleClassType type = test ? RuleClassType.TEST : RuleClassType.NORMAL; RuleClass parent = test ? testBaseRule : (executable ? binaryBaseRule : baseRule); // We'll set the name later, pass the empty string for now. RuleClass.Builder builder = new RuleClass.Builder("", type, true, parent); if (attrs != Runtime.NONE) { for (Map.Entry attr : castMap(attrs, String.class, Attribute.Builder.class, "attrs").entrySet()) { Attribute.Builder attrBuilder = (Attribute.Builder) attr.getValue(); String attrName = attributeToNative(attr.getKey(), ast.getLocation(), attrBuilder.hasLateBoundValue()); addAttribute(builder, attrBuilder.build(attrName)); } } if (executable || test) { addAttribute( builder, attr("$is_executable", BOOLEAN) .value(true) .nonconfigurable("Called from RunCommand.isExecutable, which takes a Target") .build()); builder.setOutputsDefaultExecutable(); } if (implicitOutputs != Runtime.NONE) { if (implicitOutputs instanceof BaseFunction) { BaseFunction func = (BaseFunction) implicitOutputs; SkylarkCallbackFunction callback = new SkylarkCallbackFunction(func, ast, funcallEnv); builder.setImplicitOutputsFunction( new SkylarkImplicitOutputsFunctionWithCallback(callback, ast.getLocation())); } else { builder.setImplicitOutputsFunction( new SkylarkImplicitOutputsFunctionWithMap( ImmutableMap.copyOf(castMap( implicitOutputs, String.class, String.class, "implicit outputs of the rule class")))); } } if (outputToGenfiles) { builder.setOutputToGenfiles(); } registerRequiredFragments(fragments, hostFragments, builder); builder.setConfiguredTargetFunction(implementation); builder.setRuleDefinitionEnvironment(funcallEnv); return new RuleFunction(builder, type); } private void addAttribute(RuleClass.Builder builder, Attribute attribute) throws EvalException { try { builder.addOrOverrideAttribute(attribute); } catch (IllegalArgumentException ex) { throw new EvalException(location, ex); } } private void registerRequiredFragments( SkylarkList fragments, SkylarkList hostFragments, RuleClass.Builder builder) { Map> map = new HashMap<>(); addFragmentsToMap(map, fragments, NONE); // NONE represents target configuration addFragmentsToMap(map, hostFragments, HOST); builder.requiresConfigurationFragments(new SkylarkModuleNameResolver(), map); } private void addFragmentsToMap(Map> map, SkylarkList fragments, ConfigurationTransition config) { if (!fragments.isEmpty()) { map.put(config, ImmutableSet.copyOf(castList(fragments, String.class))); } } }; // This class is needed for testing public static final class RuleFunction extends BaseFunction { // Note that this means that we can reuse the same builder. // This is fine since we don't modify the builder from here. private final RuleClass.Builder builder; private final RuleClassType type; private PathFragment skylarkFile; private String ruleClassName; public RuleFunction(Builder builder, RuleClassType type) { super("rule", FunctionSignature.KWARGS); this.builder = builder; this.type = type; } @Override @SuppressWarnings("unchecked") // the magic hidden $pkg_context variable is guaranteed // to be a PackageContext public Object call(Object[] args, FuncallExpression ast, Environment env) throws EvalException, InterruptedException, ConversionException { env.checkLoadingPhase(getName(), ast.getLocation()); try { if (ruleClassName == null || skylarkFile == null) { throw new EvalException(ast.getLocation(), "Invalid rule class hasn't been exported by a Skylark file"); } if (type == RuleClassType.TEST != TargetUtils.isTestRuleName(ruleClassName)) { throw new EvalException(ast.getLocation(), "Invalid rule class name '" + ruleClassName + "', test rule class names must end with '_test' and other rule classes must not"); } RuleClass ruleClass = builder.build(ruleClassName); PackageContext pkgContext = (PackageContext) env.lookup(PackageFactory.PKG_CONTEXT); return RuleFactory.createAndAddRule( pkgContext, ruleClass, (Map) args[0], ast, env); } catch (InvalidRuleException | NameConflictException | NoSuchVariableException e) { throw new EvalException(ast.getLocation(), e.getMessage()); } } /** * Export a RuleFunction from a Skylark file with a given name. */ void export(PathFragment skylarkFile, String ruleClassName) { this.skylarkFile = skylarkFile; this.ruleClassName = ruleClassName; } @VisibleForTesting public RuleClass.Builder getBuilder() { return builder; } } public static void exportRuleFunctions(Environment env, PathFragment skylarkFile) { for (String name : env.getGlobals().getDirectVariableNames()) { try { Object value = env.lookup(name); if (value instanceof RuleFunction) { RuleFunction function = (RuleFunction) value; if (function.skylarkFile == null) { function.export(skylarkFile, name); } } } catch (NoSuchVariableException e) { throw new AssertionError(e); } } } @SkylarkSignature(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: 
Label(\"//tools:default\")
", returnType = Label.class, mandatoryPositionals = {@Param(name = "label_string", type = String.class, doc = "the label string")}, useLocation = true) private static final BuiltinFunction label = new BuiltinFunction("Label") { public Label invoke(String labelString, Location loc) throws EvalException, ConversionException { try { return labelCache.get(labelString); } catch (ExecutionException e) { throw new EvalException(loc, "Illegal absolute label syntax: " + labelString); } } }; @SkylarkSignature(name = "FileType", doc = "Creates a file filter from a list of strings. For example, to match files ending " + "with .cc or .cpp, use: 
FileType([\".cc\", \".cpp\"])
", returnType = SkylarkFileType.class, mandatoryPositionals = { @Param(name = "types", type = SkylarkList.class, generic1 = String.class, defaultValue = "[]", doc = "a list of the accepted file extensions")}) private static final BuiltinFunction fileType = new BuiltinFunction("FileType") { public SkylarkFileType invoke(SkylarkList types) throws ConversionException { return SkylarkFileType.of(castList(types, String.class)); } }; @SkylarkSignature(name = "to_proto", doc = "Creates a text message from the struct parameter. This method only works if all " + "struct elements (recursively) are strings, ints, booleans, other structs or a " + "list of these types. Quotes and new lines in strings are escaped. " + "Examples:
"
          + "struct(key=123).to_proto()\n# key: 123\n\n"
          + "struct(key=True).to_proto()\n# key: true\n\n"
          + "struct(key=[1, 2, 3]).to_proto()\n# key: 1\n# key: 2\n# key: 3\n\n"
          + "struct(key='text').to_proto()\n# key: \"text\"\n\n"
          + "struct(key=struct(inner_key='text')).to_proto()\n"
          + "# key {\n#   inner_key: \"text\"\n# }\n\n"
          + "struct(key=[struct(inner_key=1), struct(inner_key=2)]).to_proto()\n"
          + "# key {\n#   inner_key: 1\n# }\n# key {\n#   inner_key: 2\n# }\n\n"
          + "struct(key=struct(inner_key=struct(inner_inner_key='text'))).to_proto()\n"
          + "# key {\n#    inner_key {\n#     inner_inner_key: \"text\"\n#   }\n# }\n
", objectType = SkylarkClassObject.class, returnType = String.class, mandatoryPositionals = { // TODO(bazel-team): shouldn't we accept any ClassObject? @Param(name = "self", type = SkylarkClassObject.class, doc = "this struct")}, useLocation = true) private static final BuiltinFunction toProto = new BuiltinFunction("to_proto") { public String invoke(SkylarkClassObject self, Location loc) throws EvalException { StringBuilder sb = new StringBuilder(); printTextMessage(self, sb, 0, loc); return sb.toString(); } private void printTextMessage(ClassObject object, StringBuilder sb, int indent, Location loc) throws EvalException { for (String key : object.getKeys()) { printTextMessage(key, object.getValue(key), sb, indent, loc); } } private void printSimpleTextMessage(String key, Object value, StringBuilder sb, int indent, Location loc, String container) throws EvalException { if (value instanceof ClassObject) { print(sb, key + " {", indent); printTextMessage((ClassObject) value, sb, indent + 1, loc); print(sb, "}", indent); } else if (value instanceof String) { print(sb, key + ": \"" + escape((String) value) + "\"", indent); } else if (value instanceof Integer) { print(sb, key + ": " + value, indent); } else if (value instanceof Boolean) { // We're relying on the fact that Java converts Booleans to Strings in the same way // as the protocol buffers do. print(sb, key + ": " + value, indent); } else { throw new EvalException(loc, "Invalid text format, expected a struct, a string, a bool, or an int but got a " + EvalUtils.getDataTypeName(value) + " for " + container + " '" + key + "'"); } } private void printTextMessage(String key, Object value, StringBuilder sb, int indent, Location loc) throws EvalException { if (value instanceof SkylarkList) { for (Object item : ((SkylarkList) value)) { // TODO(bazel-team): There should be some constraint on the fields of the structs // in the same list but we ignore that for now. printSimpleTextMessage(key, item, sb, indent, loc, "list element in struct field"); } } else { printSimpleTextMessage(key, value, sb, indent, loc, "struct field"); } } private String escape(String string) { // TODO(bazel-team): use guava's SourceCodeEscapers when it's released. return string.replace("\"", "\\\"").replace("\n", "\\n"); } private void print(StringBuilder sb, String text, int indent) { for (int i = 0; i < indent; i++) { sb.append(" "); } sb.append(text); sb.append("\n"); } }; static { SkylarkSignatureProcessor.configureSkylarkFunctions(SkylarkRuleClassFunctions.class); } }