| // 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.base.Preconditions; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryTaskFuture; |
| import java.util.Collection; |
| import java.util.Set; |
| |
| /** |
| * A literal set of targets, using 'blaze build' syntax. Or, a reference to a |
| * variable name. (The syntax of the string "pattern" determines which.) |
| * |
| * TODO(bazel-team): Perhaps we should distinguish NAME from WORD in the parser, |
| * based on the characters in it? Also, perhaps we should not allow NAMEs to |
| * be quoted like WORDs can be. |
| * |
| * <pre>expr ::= NAME | WORD</pre> |
| */ |
| public final class TargetLiteral extends QueryExpression { |
| |
| private final String pattern; |
| |
| public TargetLiteral(String pattern) { |
| this.pattern = Preconditions.checkNotNull(pattern); |
| } |
| |
| public String getPattern() { |
| return pattern; |
| } |
| |
| public boolean isVariableReference() { |
| return LetExpression.isValidVarReference(pattern); |
| } |
| |
| private <T> QueryTaskFuture<Void> evalVarReference( |
| QueryEnvironment<T> env, QueryExpressionContext<T> context, Callback<T> callback) { |
| String varName = LetExpression.getNameFromReference(pattern); |
| Set<T> value = context.get(varName); |
| if (value == null) { |
| return env.immediateFailedFuture( |
| new QueryException(this, "undefined variable '" + varName + "'")); |
| } |
| try { |
| callback.process(value); |
| return env.immediateSuccessfulFuture(null); |
| } catch (QueryException e) { |
| return env.immediateFailedFuture(e); |
| } catch (InterruptedException e) { |
| return env.immediateCancelledFuture(); |
| } |
| } |
| |
| @Override |
| public <T> QueryTaskFuture<Void> eval( |
| QueryEnvironment<T> env, QueryExpressionContext<T> context, Callback<T> callback) { |
| if (isVariableReference()) { |
| return evalVarReference(env, context, callback); |
| } else { |
| return env.getTargetsMatchingPattern(this, pattern, callback); |
| } |
| } |
| |
| @Override |
| public void collectTargetPatterns(Collection<String> literals) { |
| if (!isVariableReference()) { |
| literals.add(pattern); |
| } |
| } |
| |
| @Override |
| public <T, C> T accept(QueryExpressionVisitor<T, C> visitor, C context) { |
| return visitor.visit(this, context); |
| } |
| |
| @Override |
| public String toString() { |
| // Keep predicate consistent with Lexer.scanWord! |
| boolean needsQuoting = Lexer.isReservedWord(pattern) |
| || pattern.isEmpty() |
| || "$-*".indexOf(pattern.charAt(0)) != -1; |
| return needsQuoting ? ("\"" + pattern + "\"") : pattern; |
| } |
| } |