/*
* Copyright 2013 Google Inc. 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.errorprone.matchers;
import com.google.common.collect.ImmutableList;
import com.google.errorprone.VisitorState;
import com.sun.source.tree.BlockTree;
import com.sun.source.tree.CaseTree;
import com.sun.source.tree.ClassTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.StatementTree;
import com.sun.source.tree.Tree;
import java.util.List;
/**
* Adapt matchers to match against a parent node of a given type. For example, match a node if the
* enclosing class matches a predicate.
* @author alexeagle@google.com (Alex Eagle)
*/
public class Enclosing {
private Enclosing() {}
private static abstract class EnclosingMatcher<T extends Tree, U> implements Matcher<U> {
protected final Matcher<T> matcher;
protected final java.lang.Class<T> clazz;
protected EnclosingMatcher(Matcher<T> matcher, java.lang.Class<T> clazz) {
this.matcher = matcher;
this.clazz = clazz;
}
@Override
public boolean matches(U unused, VisitorState state) {
T enclosing = state.findEnclosing(clazz);
// No match if there is no enclosing element to match against
if (enclosing == null) {
return false;
}
return matcher.matches(enclosing, state);
}
}
public static class Block<T extends Tree> extends EnclosingMatcher<BlockTree, T> {
public Block(Matcher<BlockTree> matcher) {
super(matcher, BlockTree.class);
}
}
public static class Class<T extends Tree> extends EnclosingMatcher<ClassTree, T> {
public Class(Matcher<ClassTree> matcher) {
super(matcher, ClassTree.class);
}
}
public static class Method<T extends Tree> extends EnclosingMatcher<MethodTree, T> {
public Method(Matcher<MethodTree> matcher) {
super(matcher, MethodTree.class);
}
}
public static class BlockOrCase<T extends Tree> implements Matcher<T> {
private final Matcher<List<StatementTree>> matcher;
public BlockOrCase(Matcher<List<StatementTree>> matcher) {
this.matcher = matcher;
}
@Override
public boolean matches(T unused, VisitorState state) {
Tree enclosing = state.findEnclosing(CaseTree.class, BlockTree.class);
if (enclosing == null) {
return false;
}
final List<? extends StatementTree> statements;
if (enclosing instanceof BlockTree) {
statements = ((BlockTree)enclosing).getStatements();
} else if (enclosing instanceof CaseTree) {
statements = ((CaseTree)enclosing).getStatements();
} else {
// findEnclosing given two types must return something of one of those types
throw new IllegalStateException("enclosing tree not a BlockTree or CaseTree");
}
return matcher.matches(ImmutableList.copyOf(statements), state);
}
}
}