com.google.errorprone.bugpatterns.flogger.FloggerLogWithCause Maven / Gradle / Ivy
/*
* Copyright 2020 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.flogger;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.fixes.SuggestedFix.postfixWith;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.matchers.Matchers.instanceMethod;
import static com.google.errorprone.util.ASTHelpers.getReceiver;
import static com.google.errorprone.util.ASTHelpers.getSymbol;
import static java.lang.Boolean.TRUE;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.bugpatterns.BugChecker.CatchTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.sun.source.tree.CatchTree;
import com.sun.source.tree.ExpressionStatementTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.StatementTree;
import com.sun.source.util.TreeScanner;
import com.sun.tools.javac.code.Symbol;
import java.util.List;
/**
* Flags cases where there is an exception available that could be set as the cause in a log
* message.
*/
@BugPattern(
name = "FloggerLogWithCause",
summary =
"Setting the caught exception as the cause of the log message may provide more context for"
+ " anyone debugging errors.",
severity = WARNING)
public final class FloggerLogWithCause extends BugChecker implements CatchTreeMatcher {
private static final Matcher LOG_MATCHER =
instanceMethod().onDescendantOf("com.google.common.flogger.LoggingApi").named("log");
private static final Matcher WITH_CAUSE =
instanceMethod().onDescendantOf("com.google.common.flogger.LoggingApi").named("withCause");
private static final Matcher HIGH_LEVEL =
instanceMethod()
.onDescendantOf("com.google.common.flogger.AbstractLogger")
.namedAnyOf("atWarning", "atSevere");
@Override
public Description matchCatch(CatchTree tree, VisitorState state) {
if (isSuppressed(tree.getParameter())) {
return Description.NO_MATCH;
}
List statements = tree.getBlock().getStatements();
if (statements.size() != 1) {
return NO_MATCH;
}
StatementTree statementTree = statements.get(0);
if (!(statementTree instanceof ExpressionStatementTree)) {
return NO_MATCH;
}
ExpressionTree expressionTree = ((ExpressionStatementTree) statementTree).getExpression();
if (!LOG_MATCHER.matches(expressionTree, state)) {
return NO_MATCH;
}
boolean isHighLevelLog = false;
for (ExpressionTree receiver = expressionTree;
receiver instanceof MethodInvocationTree;
receiver = getReceiver(receiver)) {
if (WITH_CAUSE.matches(receiver, state)) {
return NO_MATCH;
}
if (HIGH_LEVEL.matches(receiver, state)) {
isHighLevelLog = true;
}
}
if (!isHighLevelLog) {
return NO_MATCH;
}
Symbol parameter = getSymbol(tree.getParameter());
boolean exceptionUsed =
new TreeScanner() {
@Override
public Boolean visitIdentifier(IdentifierTree node, Void unused) {
return parameter.equals(getSymbol(node));
}
@Override
public Boolean reduce(Boolean a, Boolean b) {
return TRUE.equals(a) || TRUE.equals(b);
}
}.scan(tree.getBlock(), null);
if (exceptionUsed) {
return NO_MATCH;
}
String withCause = String.format(".withCause(%s)", tree.getParameter().getName());
return describeMatch(expressionTree, postfixWith(getReceiver(expressionTree), withCause));
}
}