com.google.errorprone.bugpatterns.InfiniteRecursion Maven / Gradle / Ivy
/*
* Copyright 2016 The Error Prone Authors.
*
* 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.bugpatterns;
import static com.google.common.collect.Iterables.getOnlyElement;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.stripParentheses;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionStatementTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MemberSelectTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.tree.ReturnTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.Tree.Kind;
import com.sun.source.util.SimpleTreeVisitor;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
/** A {@link BugChecker}; see the associated {@link BugPattern} annotation for details. */
@BugPattern(
name = "InfiniteRecursion",
summary = "This method always recurses, and will cause a StackOverflowError",
severity = ERROR)
public class InfiniteRecursion extends BugChecker implements BugChecker.MethodTreeMatcher {
@Override
public Description matchMethod(MethodTree tree, VisitorState state) {
if (tree.getBody() == null || tree.getBody().getStatements().size() != 1) {
return NO_MATCH;
}
Tree statement = stripParentheses(getOnlyElement(tree.getBody().getStatements()));
ExpressionTree expr =
statement.accept(
new SimpleTreeVisitor() {
@Override
public ExpressionTree visitExpressionStatement(
ExpressionStatementTree tree, Void unused) {
return tree.getExpression();
}
@Override
public ExpressionTree visitReturn(ReturnTree tree, Void unused) {
return tree.getExpression();
}
},
null);
if (!(expr instanceof MethodInvocationTree)) {
return NO_MATCH;
}
ExpressionTree select = ((MethodInvocationTree) expr).getMethodSelect();
MethodSymbol sym = ASTHelpers.getSymbol(tree);
if (sym == null || !sym.equals(ASTHelpers.getSymbol(expr))) {
return NO_MATCH;
}
if (!sym.isStatic()) {
switch (select.getKind()) {
case IDENTIFIER:
break;
case MEMBER_SELECT:
ExpressionTree receiver = ((MemberSelectTree) select).getExpression();
if (receiver.getKind() != Kind.IDENTIFIER) {
return NO_MATCH;
}
if (!((IdentifierTree) receiver).getName().contentEquals("this")) {
return NO_MATCH;
}
break;
default:
return NO_MATCH;
}
}
return describeMatch(statement);
}
}