com.google.errorprone.bugpatterns.TreeToString Maven / Gradle / Ivy
/*
* Copyright 2018 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.common.collect.Iterables.getOnlyElement;
import static com.google.common.collect.Streams.stream;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Matchers.instanceMethod;
import static com.google.errorprone.util.ASTHelpers.getReceiver;
import static com.google.errorprone.util.ASTHelpers.isSubtype;
import com.google.errorprone.BugPattern;
import com.google.errorprone.ErrorProneFlags;
import com.google.errorprone.VisitorState;
import com.google.errorprone.fixes.Fix;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Matcher;
import com.google.errorprone.matchers.Matchers;
import com.google.errorprone.predicates.TypePredicate;
import com.google.errorprone.predicates.TypePredicates;
import com.google.errorprone.suppliers.Supplier;
import com.google.errorprone.util.FindIdentifiers;
import com.sun.source.tree.ClassTree;
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.VarSymbol;
import com.sun.tools.javac.code.Type;
import java.util.Optional;
import javax.inject.Inject;
/**
* Flags {@code com.sun.source.tree.Tree#toString} usage in {@link BugChecker}s.
*
* @author [email protected] (Sumit Bhagwani)
*/
@BugPattern(
summary =
"Tree#toString shouldn't be used for Trees deriving from the code being compiled, as it"
+ " discards whitespace and comments.",
severity = ERROR)
public class TreeToString extends AbstractToString {
private static final Matcher IS_BUGCHECKER =
Matchers.isSubtypeOf("com.google.errorprone.bugpatterns.BugChecker");
private static final TypePredicate IS_TREE =
TypePredicates.isDescendantOf("com.sun.source.tree.Tree");
private static final Matcher TREEMAKER_LITERAL_CREATOR =
instanceMethod()
.onDescendantOf("com.sun.tools.javac.tree.TreeMaker")
.named("Literal")
.withParameters("java.lang.Object");
@Inject
TreeToString(ErrorProneFlags flags) {
super(flags);
}
@Override
protected TypePredicate typePredicate() {
return this::treeToStringInBugChecker;
}
private boolean treeToStringInBugChecker(Type type, VisitorState state) {
return enclosingBugChecker(state) && IS_TREE.apply(type, state);
}
private boolean enclosingBugChecker(VisitorState state) {
return stream(state.getPath())
.anyMatch(t -> t instanceof ClassTree && IS_BUGCHECKER.matches((ClassTree) t, state));
}
@Override
protected Optional descriptionMessageForDefaultMatch(Type type, VisitorState state) {
return Optional.of("Tree#toString shouldn't be used.");
}
@Override
protected Optional implicitToStringFix(ExpressionTree tree, VisitorState state) {
return fix(tree, tree, state);
}
@Override
protected Optional toStringFix(Tree parent, ExpressionTree tree, VisitorState state) {
if (!(parent instanceof MethodInvocationTree)) {
return Optional.empty();
}
ExpressionTree receiver = getReceiver((ExpressionTree) parent);
if (receiver == null) {
return Optional.empty();
}
return fix(receiver, parent, state);
}
private static Optional fix(Tree target, Tree replace, VisitorState state) {
return FindIdentifiers.findAllIdents(state).stream()
.filter(s -> isSubtype(s.type, COM_GOOGLE_ERRORPRONE_VISITORSTATE.get(state), state))
.findFirst()
.map(s -> SuggestedFix.replace(replace, createStringReplacement(state, s, target)));
}
private static String createStringReplacement(
VisitorState state, VarSymbol visitorStateSymbol, Tree target) {
String visitorStateVariable = visitorStateSymbol.getSimpleName().toString();
if (target instanceof MethodInvocationTree) {
MethodInvocationTree targetMethodInvocationTree = (MethodInvocationTree) target;
if (TREEMAKER_LITERAL_CREATOR.matches(targetMethodInvocationTree, state)) {
return String.format(
"%s.getConstantExpression(%s)",
visitorStateVariable,
state.getSourceForNode(getOnlyElement(targetMethodInvocationTree.getArguments())));
}
}
return String.format(
"%s.getSourceForNode(%s)", visitorStateVariable, state.getSourceForNode(target));
}
private static final Supplier COM_GOOGLE_ERRORPRONE_VISITORSTATE =
VisitorState.memoize(state -> state.getTypeFromString("com.google.errorprone.VisitorState"));
}