com.google.errorprone.bugpatterns.javadoc.InvalidThrows 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.javadoc;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.bugpatterns.javadoc.Utils.diagnosticPosition;
import static com.google.errorprone.util.ASTHelpers.getType;
import static com.google.errorprone.util.ASTHelpers.isSubtype;
import com.google.errorprone.BugPattern;
import com.google.errorprone.BugPattern.StandardTags;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker;
import com.google.errorprone.bugpatterns.BugChecker.MethodTreeMatcher;
import com.google.errorprone.matchers.Description;
import com.sun.source.doctree.ReferenceTree;
import com.sun.source.doctree.ThrowsTree;
import com.sun.source.tree.MethodTree;
import com.sun.source.util.DocTreePath;
import com.sun.source.util.DocTreePathScanner;
import com.sun.tools.javac.api.JavacTrees;
import com.sun.tools.javac.code.Type;
import javax.lang.model.element.Element;
/**
* Matches errors in Javadoc {@literal @}throws tags.
*
* @author [email protected] (Graeme Morgan)
*/
@BugPattern(
name = "InvalidThrows",
summary = "The documented method doesn't actually throw this checked exception.",
severity = WARNING,
tags = StandardTags.STYLE,
documentSuppression = false)
public final class InvalidThrows extends BugChecker implements MethodTreeMatcher {
@Override
public Description matchMethod(MethodTree methodTree, VisitorState state) {
DocTreePath path = Utils.getDocTreePath(state);
if (path != null) {
new ThrowsChecker(state, methodTree).scan(path, null);
}
return Description.NO_MATCH;
}
private final class ThrowsChecker extends DocTreePathScanner {
private final VisitorState state;
private final MethodTree methodTree;
private ThrowsChecker(VisitorState state, MethodTree methodTree) {
this.state = state;
this.methodTree = methodTree;
}
@Override
public Void visitThrows(ThrowsTree throwsTree, Void unused) {
ReferenceTree exName = throwsTree.getExceptionName();
Element element =
JavacTrees.instance(state.context).getElement(new DocTreePath(getCurrentPath(), exName));
if (element != null) {
Type type = (Type) element.asType();
if (isCheckedException(type)) {
if (methodTree.getThrows().stream().noneMatch(t -> isSubtype(type, getType(t), state))) {
state.reportMatch(
describeMatch(
diagnosticPosition(getCurrentPath(), state),
Utils.replace(throwsTree, "", state)));
}
}
}
return super.visitThrows(throwsTree, null);
}
private boolean isCheckedException(Type type) {
return !state.getTypes().isAssignable(type, state.getSymtab().errorType)
&& !state.getTypes().isAssignable(type, state.getSymtab().runtimeExceptionType);
}
}
}