| // 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.query2.engine; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.Argument; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ArgumentType; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryFunction; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryTaskFuture; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * A label(attr_name, argument) expression, which computes the set of targets whose labels appear in |
| * the specified attribute of some rule in 'argument'. |
| * |
| * <pre>expr ::= LABELS '(' WORD ',' expr ')'</pre> |
| * |
| * Example: |
| * |
| * <pre> |
| * labels(srcs, //foo) The 'srcs' source files to the //foo rule. |
| * </pre> |
| */ |
| public class LabelsFunction implements QueryFunction { |
| LabelsFunction() { |
| } |
| |
| @Override |
| public String getName() { |
| return "labels"; |
| } |
| |
| @Override |
| public int getMandatoryArguments() { |
| return 2; |
| } |
| |
| @Override |
| public List<ArgumentType> getArgumentTypes() { |
| return ImmutableList.of(ArgumentType.WORD, ArgumentType.EXPRESSION); |
| } |
| |
| @Override |
| public <T> QueryTaskFuture<Void> eval( |
| final QueryEnvironment<T> env, |
| QueryExpressionContext<T> context, |
| final QueryExpression expression, |
| final List<Argument> args, |
| final Callback<T> callback) { |
| final String attrName = args.get(0).getWord(); |
| final Uniquifier<T> uniquifier = env.createUniquifier(); |
| return env.eval(args.get(1).getExpression(), context, new Callback<T>() { |
| @Override |
| public void process(Iterable<T> partialResult) throws QueryException, InterruptedException { |
| for (T input : partialResult) { |
| if (env.getAccessor().isRule(input)) { |
| List<T> targets = uniquifier.unique( |
| env.getAccessor().getLabelListAttr(expression, input, attrName, |
| "in '" + attrName + "' of rule " + env.getAccessor().getLabel(input) + ": ")); |
| List<T> result = new ArrayList<>(targets.size()); |
| for (T target : targets) { |
| result.add(env.getOrCreate(target)); |
| } |
| callback.process(result); |
| } |
| } |
| |
| } |
| }); |
| } |
| } |