/*
* Copyright 2015 Google Inc. All Rights Reserved.
*
* 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.Category.JDK;
import static com.google.errorprone.BugPattern.SeverityLevel.ERROR;
import static com.google.errorprone.matchers.Matchers.anyOf;
import static com.google.errorprone.matchers.method.MethodMatchers.instanceMethod;
import com.google.common.collect.Iterables;
import com.google.errorprone.BugPattern;
import com.google.errorprone.VisitorState;
import com.google.errorprone.bugpatterns.BugChecker.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.Fix;
import com.google.errorprone.fixes.SuggestedFix;
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.MethodInvocationTree;
import com.sun.tools.javac.code.Type;
import com.sun.tools.javac.code.Types;
import com.sun.tools.javac.tree.JCTree;
import com.sun.tools.javac.util.List;
import java.util.Hashtable;
import java.util.concurrent.ConcurrentHashMap;
/** @author cushon@google.com (Liam Miller-Cushon) */
@BugPattern(
name = "HashtableContains",
summary = "contains() is a legacy method that is equivalent to containsValue()",
category = JDK,
severity = ERROR
)
public class HashtableContains extends BugChecker implements MethodInvocationTreeMatcher {
static final Matcher<ExpressionTree> CONTAINS_MATCHER =
anyOf(
instanceMethod().onDescendantOf(Hashtable.class.getName()).named("contains"),
instanceMethod().onDescendantOf(ConcurrentHashMap.class.getName()).named("contains"));
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (!CONTAINS_MATCHER.matches(tree, state)) {
return Description.NO_MATCH;
}
Description.Builder result = buildDescription(tree);
// If the collection is not raw, try to figure out if the argument looks like a key
// or a value.
List<Type> tyargs = ASTHelpers.getReceiverType(tree).getTypeArguments();
if (tyargs.size() == 2) {
// map capture variables to their bounds, e.g. `? extends Number` -> `Number`
Types types = state.getTypes();
Type key = ASTHelpers.getUpperBound(tyargs.get(0), types);
Type value = ASTHelpers.getUpperBound(tyargs.get(1), types);
Type arg = ASTHelpers.getType(Iterables.getOnlyElement(tree.getArguments()));
boolean valueShaped = types.isAssignable(arg, value);
boolean keyShaped = types.isAssignable(arg, key);
if (keyShaped && !valueShaped) {
// definitely a key
result.addFix(replaceMethodName(tree, state, "containsKey"));
result.setMessage(
String.format(
"contains() is a legacy method that is equivalent to containsValue(), but the "
+ "argument type '%s' looks like a key",
key));
} else if (valueShaped && !keyShaped) {
// definitely a value
result.addFix(replaceMethodName(tree, state, "containsValue"));
} else if (valueShaped && keyShaped) {
// ambiguous
result.addFix(replaceMethodName(tree, state, "containsValue"));
result.addFix(replaceMethodName(tree, state, "containsKey"));
result.setMessage(
String.format(
"contains() is a legacy method that is equivalent to containsValue(), but the "
+ "argument type '%s' could be a key or a value",
key));
} else {
// this shouldn't have compiled!
throw new AssertionError(
String.format(
"unexpected argument to contains(): key: %s, value: %s, argument: %s",
key,
value,
arg));
}
} else {
result.addFix(replaceMethodName(tree, state, "containsValue"));
}
return result.build();
}
private Fix replaceMethodName(MethodInvocationTree tree, VisitorState state, String newName) {
String source = state.getSourceForNode((JCTree) tree.getMethodSelect()).toString();
int idx = source.lastIndexOf("contains");
String replacement =
source.substring(0, idx) + newName + source.substring(idx + "contains".length());
Fix fix = SuggestedFix.replace(tree.getMethodSelect(), replacement);
return fix;
}
}