com.google.errorprone.bugpatterns.NullTernary Maven / Gradle / Ivy
/*
* Copyright 2017 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.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.ConditionalExpressionTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ConditionalExpressionTree;
import com.sun.source.tree.Tree.Kind;
/** A {@link BugChecker}; see the associated {@link BugPattern} annotation for details. */
@BugPattern(
summary =
"This conditional expression may evaluate to null, which will result in an NPE when the"
+ " result is unboxed.",
severity = ERROR)
public class NullTernary extends BugChecker implements ConditionalExpressionTreeMatcher {
@Override
public Description matchConditionalExpression(
ConditionalExpressionTree conditionalExpression, VisitorState state) {
if (conditionalExpression.getFalseExpression().getKind() != Kind.NULL_LITERAL
&& conditionalExpression.getTrueExpression().getKind() != Kind.NULL_LITERAL) {
return NO_MATCH;
}
ASTHelpers.TargetType targetType = ASTHelpers.targetType(state);
if (targetType == null || !targetType.type().isPrimitive()) {
return NO_MATCH;
}
return describeMatch(conditionalExpression);
}
}