com.google.errorprone.bugpatterns.WaitNotInLoop Maven / Gradle / Ivy
/*
* Copyright 2013 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.
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package com.google.errorprone.bugpatterns;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.matchers.Matchers.allOf;
import static com.google.errorprone.matchers.Matchers.inLoop;
import static com.google.errorprone.matchers.Matchers.not;
import static com.google.errorprone.matchers.WaitMatchers.waitMethod;
import static com.google.errorprone.matchers.WaitMatchers.waitMethodWithTimeout;
import com.google.errorprone.BugPattern;
import com.google.errorprone.BugPattern.StandardTags;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.tree.JCTree.JCIf;
/** @author [email protected] (Eddie Aftandilian) */
// TODO(eaftan): Doesn't handle the case that the enclosing method is always called in a loop.
@BugPattern(
name = "WaitNotInLoop",
summary =
"Because of spurious wakeups, Object.wait() and Condition.await() must always be "
+ "called in a loop",
severity = WARNING,
tags = StandardTags.FRAGILE_CODE)
public class WaitNotInLoop extends BugChecker implements MethodInvocationTreeMatcher {
private static final String MESSAGE_TEMPLATE =
"Because of spurious wakeups, %s must always be called in a loop";
private static final Matcher matcher = allOf(waitMethod, not(inLoop()));
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (!matcher.matches(tree, state)) {
return Description.NO_MATCH;
}
Description.Builder description = buildDescription(tree);
MethodSymbol sym = ASTHelpers.getSymbol(tree);
if (sym != null) {
description.setMessage(String.format(MESSAGE_TEMPLATE, sym));
}
// If this looks like the "Wait until a condition becomes true" case from the wiki content,
// rewrite the enclosing if to a while. Other fixes are too complicated to construct
// mechanically, so we provide detailed instructions in the wiki content.
if (!waitMethodWithTimeout.matches(tree, state)) {
JCIf enclosingIf = ASTHelpers.findEnclosingNode(state.getPath().getParentPath(), JCIf.class);
if (enclosingIf != null && enclosingIf.getElseStatement() == null) {
CharSequence ifSource = state.getSourceForNode(enclosingIf);
if (ifSource == null) {
// Source isn't available, so we can't construct a fix
return description.build();
}
String replacement = ifSource.toString().replaceFirst("if", "while");
return description.addFix(SuggestedFix.replace(enclosingIf, replacement)).build();
}
}
return description.build();
}
}