/*
* Copyright 2016 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.bugpatterns;
import static com.google.errorprone.BugPattern.Category.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.SUGGESTION;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.getType;
import static com.google.errorprone.util.ASTHelpers.isSubtype;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
import com.google.errorprone.fixes.SuggestedFixes;
import com.google.errorprone.matchers.Description;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodTree;
import com.sun.tools.javac.code.Type;
import java.util.ArrayList;
import java.util.List;
/**
* Suggests to remove the unchecked throws clause.
*
* @author yulissa@google.com (Yulissa Arroyo-Paredes)
*/
@BugPattern(
name = "ThrowsUncheckedException",
summary = "Unchecked exceptions do not need to be declared in the method signature.",
category = JDK,
severity = SUGGESTION,
generateExamplesFromTestCases = false
)
public class ThrowsUncheckedException extends BugChecker implements MethodTreeMatcher {
@Override
public Description matchMethod(MethodTree tree, VisitorState state) {
if (tree.getThrows().isEmpty()) {
return NO_MATCH;
}
List<ExpressionTree> uncheckedExceptions = new ArrayList<>();
for (ExpressionTree exception : tree.getThrows()) {
Type exceptionType = getType(exception);
if (isSubtype(exceptionType, state.getSymtab().runtimeExceptionType, state)
|| isSubtype(exceptionType, state.getSymtab().errorType, state)) {
uncheckedExceptions.add(exception);
}
}
if (uncheckedExceptions.isEmpty()) {
return NO_MATCH;
}
return describeMatch(
uncheckedExceptions.get(0),
SuggestedFixes.deleteExceptions(tree, state, uncheckedExceptions));
}
}