com.google.errorprone.bugpatterns.nullness.ExtendsObject Maven / Gradle / Ivy
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* Copyright 2022 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.nullness;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.util.ASTHelpers.getType;
import static java.lang.String.format;
import com.google.errorprone.BugPattern;
import com.google.errorprone.BugPattern.SeverityLevel;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.bugpatterns.BugChecker.TypeParameterTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.fixes.SuggestedFixes;
import com.google.errorprone.matchers.Description;
import com.sun.source.tree.AnnotatedTypeTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.TypeParameterTree;
/** A bugpattern: see the summary. */
@BugPattern(
summary = "`T extends Object` is redundant" + " (unless you are using the Checker Framework).",
severity = SeverityLevel.WARNING)
public final class ExtendsObject extends BugChecker implements TypeParameterTreeMatcher {
private static final String NON_NULL = "org.checkerframework.checker.nullness.qual.NonNull";
@Override
public Description matchTypeParameter(TypeParameterTree tree, VisitorState state) {
for (Tree bound : tree.getBounds()) {
if (!state.getTypes().isSameType(getType(bound), state.getSymtab().objectType)) {
continue;
}
if (!(bound instanceof AnnotatedTypeTree)) {
SuggestedFix.Builder fix = SuggestedFix.builder();
String nonNull = SuggestedFixes.qualifyType(state, fix, NON_NULL);
return describeMatch(bound, fix.prefixWith(bound, format(" @%s ", nonNull)).build());
}
}
return NO_MATCH;
}
}