/*
* 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.refaster;
import com.google.auto.value.AutoValue;
import com.google.common.base.Predicate;
import com.google.errorprone.VisitorState;
import com.google.errorprone.matchers.Matcher;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.TreeVisitor;
import com.sun.source.util.TreePath;
import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
import com.sun.tools.javac.tree.JCTree.JCExpression;
import com.sun.tools.javac.util.Context;
import javax.annotation.Nullable;
/**
* {@code UMatches} allows conditionally matching a {@code UExpression} predicated by an
* error-prone {@code Matcher}.
*/
@AutoValue
abstract class UMatches extends UExpression {
public static UMatches create(Class<? extends Matcher<? super ExpressionTree>> matcherClass,
boolean positive, UExpression expression) {
// Verify that we can instantiate the Matcher
makeMatcher(matcherClass);
return new AutoValue_UMatches(positive, matcherClass, expression);
}
abstract boolean positive();
abstract Class<? extends Matcher<? super ExpressionTree>> matcherClass();
abstract UExpression expression();
@Override
@Nullable
protected Choice<Unifier> defaultAction(Tree target, @Nullable Unifier unifier) {
final Tree exprTarget = UParens.skipParens(target);
return expression().unify(exprTarget, unifier).condition(new Predicate<Unifier>() {
@Override
public boolean apply(Unifier success) {
return matches(exprTarget, success) == positive();
}
});
}
@Override
public JCExpression inline(Inliner inliner) throws CouldNotResolveImportException {
throw new UnsupportedOperationException("@Matches should not appear in an @AfterTemplate");
}
@Override
public <R, D> R accept(TreeVisitor<R, D> visitor, D data) {
return expression().accept(visitor, data);
}
@Override
public Kind getKind() {
return Kind.OTHER;
}
private transient Matcher<? super ExpressionTree> matcher;
private boolean matches(Tree target, Unifier unifier) {
if (matcher == null) {
matcher = makeMatcher(matcherClass());
}
return target instanceof ExpressionTree
&& matcher.matches((ExpressionTree) target, makeVisitorState(target, unifier));
}
static <T> T makeMatcher(Class<T> klass) {
try {
return klass.newInstance();
} catch (IllegalAccessException|InstantiationException e) {
throw new RuntimeException(e);
}
}
static VisitorState makeVisitorState(Tree target, Unifier unifier) {
Context context = unifier.getContext();
TreePath path = TreePath.getPath(context.get(JCCompilationUnit.class), target);
return new VisitorState(context).withPath(path);
}
}