Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* 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.WARNING;
import static com.google.errorprone.util.ASTHelpers.getReceiver;
import static com.google.errorprone.util.ASTHelpers.getSymbol;
import static com.google.errorprone.util.ASTHelpers.hasAnnotation;
import static com.google.errorprone.util.ASTHelpers.isSameType;
import static com.google.errorprone.util.ASTHelpers.isSubtype;
import static javax.lang.model.element.Modifier.ABSTRACT;
import com.google.common.collect.ImmutableMap;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.threadsafety.ConstantExpressions;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.suppliers.Supplier;
import com.sun.source.tree.ExpressionStatementTree;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import com.sun.tools.javac.code.Type;
import java.util.Optional;
import javax.inject.Inject;
/** Flags ignored return values from pure getters. */
@BugPattern(
severity = WARNING,
summary =
"Getters on AutoValues, AutoBuilders, and Protobuf Messages are side-effect free, so there"
+ " is no point in calling them if the return value is ignored. While there are no"
+ " side effects from the getter, the receiver may have side effects.")
public final class IgnoredPureGetter extends AbstractReturnValueIgnored {
private static final Supplier MESSAGE_LITE =
VisitorState.memoize(state -> state.getTypeFromString("com.google.protobuf.MessageLite"));
private static final Supplier MUTABLE_MESSAGE_LITE =
VisitorState.memoize(
state -> state.getTypeFromString("com.google.protobuf.MutableMessageLite"));
@Inject
IgnoredPureGetter(ConstantExpressions constantExpressions) {
super(constantExpressions);
}
@Override
protected Matcher specializedMatcher() {
return IgnoredPureGetter::isPureGetter;
}
@Override
public ImmutableMap getMatchMetadata(ExpressionTree tree, VisitorState state) {
return pureGetterKind(tree, state)
.map(kind -> ImmutableMap.of("pure_getter_kind", kind))
.orElse(ImmutableMap.of());
}
@Override
protected Description describeReturnValueIgnored(
MethodInvocationTree methodInvocationTree, VisitorState state) {
Tree parent = state.getPath().getParentPath().getLeaf();
Description.Builder builder =
buildDescription(methodInvocationTree)
.addFix(
SuggestedFix.builder()
.setShortDescription("Remove with any side effects from the receiver")
.delete(
parent instanceof ExpressionStatementTree ? parent : methodInvocationTree)
.build());
ExpressionTree receiver = getReceiver(methodInvocationTree);
if (receiver instanceof MethodInvocationTree) {
builder.addFix(
SuggestedFix.builder()
.setShortDescription("Remove but keep side effects from the receiver")
.replace(methodInvocationTree, state.getSourceForNode(receiver))
.build());
}
return builder.build();
}
private static boolean isPureGetter(ExpressionTree tree, VisitorState state) {
return pureGetterKind(tree, state).isPresent();
}
private static Optional pureGetterKind(ExpressionTree tree, VisitorState state) {
Symbol rawSymbol = getSymbol(tree);
if (!(rawSymbol instanceof MethodSymbol)) {
return Optional.empty();
}
MethodSymbol symbol = (MethodSymbol) rawSymbol;
Symbol owner = symbol.owner;
if (symbol.getModifiers().contains(ABSTRACT) && symbol.getParameters().isEmpty()) {
// The return value of any abstract method on an @AutoValue needs to be used.
if (hasAnnotation(owner, "com.google.auto.value.AutoValue", state)) {
return Optional.of(PureGetterKind.AUTO_VALUE);
}
// The return value of any abstract method on an @AutoBuilder (which doesn't return the
// Builder itself) needs to be used.
if (hasAnnotation(owner, "com.google.auto.value.AutoBuilder", state)
&& !isSameType(symbol.getReturnType(), owner.type, state)) {
return Optional.of(PureGetterKind.AUTO_BUILDER);
}
// The return value of any abstract method on an @AutoValue.Builder (which doesn't return the
// Builder itself) needs to be used.
if (hasAnnotation(owner, "com.google.auto.value.AutoValue.Builder", state)
&& !isSameType(symbol.getReturnType(), owner.type, state)) {
return Optional.of(PureGetterKind.AUTO_VALUE_BUILDER);
}
}
try {
if (isSubtype(owner.type, MESSAGE_LITE.get(state), state)
&& !isSubtype(owner.type, MUTABLE_MESSAGE_LITE.get(state), state)) {
return Optional.of(PureGetterKind.PROTO);
}
} catch (Symbol.CompletionFailure ignore) {
// isSubtype may throw this if some supertype's class file isn't found
// Nothing we can do about it as far as I know
}
return Optional.empty();
}
private enum PureGetterKind {
AUTO_VALUE,
AUTO_VALUE_BUILDER,
AUTO_BUILDER,
PROTO
}
}
