com.google.errorprone.bugpatterns.ComputeIfAbsentAmbiguousReference 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;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Description.NO_MATCH;
import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
import com.google.common.collect.ImmutableList;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.util.ASTHelpers;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.IdentifierTree;
import com.sun.source.tree.MemberReferenceTree;
import com.sun.source.tree.MemberReferenceTree.ReferenceMode;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.ClassSymbol;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.util.Name;
import java.util.List;
import java.util.stream.Collectors;
/**
* Flags ambiguous creations of objects in {@link java.util.Map#computeIfAbsent}.
*
* @author [email protected] (Sumit Bhagwani)
*/
@BugPattern(
summary = "computeIfAbsent passes the map key to the provided class's constructor",
severity = ERROR)
public final class ComputeIfAbsentAmbiguousReference extends BugChecker
implements MethodInvocationTreeMatcher {
private static final Matcher COMPUTE_IF_ABSENT =
instanceMethod().onDescendantOf("java.util.Map").named("computeIfAbsent");
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (!COMPUTE_IF_ABSENT.matches(tree, state)) {
return NO_MATCH;
}
ExpressionTree mappingFunctionArg = tree.getArguments().get(1);
if (!(mappingFunctionArg instanceof MemberReferenceTree)) {
return NO_MATCH;
}
MemberReferenceTree memberReferenceTree = (MemberReferenceTree) mappingFunctionArg;
if (memberReferenceTree.getMode() != ReferenceMode.NEW) {
return NO_MATCH;
}
ExpressionTree expressionTree = memberReferenceTree.getQualifierExpression();
Symbol symbol = ASTHelpers.getSymbol(expressionTree);
if (!(symbol instanceof ClassSymbol)) {
return NO_MATCH;
}
ClassSymbol classSymbol = (ClassSymbol) symbol;
ImmutableList constructors = ASTHelpers.getConstructors(classSymbol);
List zeroArgConstructors =
constructors.stream()
.filter(methodSymbol -> methodSymbol.type.getParameterTypes().isEmpty())
.collect(Collectors.toList());
if (zeroArgConstructors.size() != 1) {
return NO_MATCH;
}
List oneArgConstructors =
constructors.stream()
.filter(methodSymbol -> methodSymbol.type.getParameterTypes().size() == 1)
.collect(Collectors.toList());
if (oneArgConstructors.isEmpty()) {
return NO_MATCH;
}
ExpressionTree onlyArgument = tree.getArguments().get(0);
if (onlyArgument instanceof IdentifierTree) {
IdentifierTree onlyArgumentIdentifier = (IdentifierTree) onlyArgument;
Name constructorParamName = oneArgConstructors.get(0).getParameters().get(0).getSimpleName();
if (constructorParamName.equals(onlyArgumentIdentifier.getName())) {
return NO_MATCH;
}
}
return describeMatch(memberReferenceTree);
}
}