/*
* Copyright 2015 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.WARNING;
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.MethodTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.AnnotationTree;
import com.sun.source.tree.MethodTree;
import com.sun.tools.javac.code.Symbol;
/** @author cushon@google.com (Liam Miller-Cushon) */
@BugPattern(
name = "NullableConstructor",
summary = "Constructors should not be annotated with @Nullable since they cannot return null",
explanation = "Constructors never return null.",
category = JDK,
severity = WARNING
)
public class NullableConstructor extends BugChecker implements MethodTreeMatcher {
@Override
public Description matchMethod(MethodTree tree, VisitorState state) {
Symbol sym = ASTHelpers.getSymbol(tree);
if (sym == null) {
return NO_MATCH;
}
if (!sym.isConstructor()) {
return NO_MATCH;
}
AnnotationTree annotation =
ASTHelpers.getAnnotationWithSimpleName(tree.getModifiers().getAnnotations(), "Nullable");
if (annotation == null) {
return NO_MATCH;
}
return describeMatch(annotation, SuggestedFix.delete(annotation));
}
}