com.google.errorprone.bugpatterns.UnsafeLocaleUsage Maven / Gradle / Ivy
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* Copyright 2020 The Error Prone Authors.
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* 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
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
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* See the License for the specific language governing permissions and
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package com.google.errorprone.bugpatterns;
import static com.google.errorprone.BugPattern.SeverityLevel.WARNING;
import static com.google.errorprone.matchers.Matchers.constructor;
import static com.google.errorprone.matchers.Matchers.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.bugpatterns.BugChecker.NewClassTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.fixes.SuggestedFixes;
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.source.tree.NewClassTree;
import com.sun.tools.javac.tree.JCTree.JCLiteral;
/** Flags unsafe usages of the {@link java.util.Locale} constructor and class methods. */
@BugPattern(
name = "UnsafeLocaleUsage",
summary = "Possible unsafe operation related to the java.util.Locale library.",
severity = WARNING)
public final class UnsafeLocaleUsage extends BugChecker
implements MethodInvocationTreeMatcher, NewClassTreeMatcher {
private static final Matcher LOCALE_TO_STRING =
instanceMethod().onExactClass("java.util.Locale").named("toString");
private static final Matcher LOCALE_CONSTRUCTOR =
constructor().forClass("java.util.Locale");
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (LOCALE_TO_STRING.matches(tree, state)) {
return buildDescription(tree)
.setMessage(
"Avoid using Locale.toString() since it produces a value that"
+ " misleadingly looks like a locale identifier. Prefer using"
+ " Locale.toLanguageTag() since it produces an IETF BCP 47-formatted string that"
+ " can be deserialized back into a Locale.")
.addFix(SuggestedFixes.renameMethodInvocation(tree, "toLanguageTag", state))
.build();
}
return Description.NO_MATCH;
}
@Override
public Description matchNewClass(NewClassTree tree, VisitorState state) {
if (LOCALE_CONSTRUCTOR.matches(tree, state)) {
Description.Builder descriptionBuilder =
buildDescription(tree)
.setMessage(
"Avoid using Locale constructors, and prefer using"
+ " Locale.forLanguageTag(String) which takes in an IETF BCP 47-formatted"
+ " string or a Locale Builder.");
// Only suggest a fix for constructor calls with one or two parameters since there's
// too much variance in multi-parameter calls to be able to make a confident suggestion
ImmutableList constructorArguments =
ImmutableList.copyOf(tree.getArguments());
if (constructorArguments.size() == 1) {
// Locale.forLanguageTag() doesn't support underscores in language tags. We can replace this
// ourselves when the constructor arg is a string literal. Otherwise, we can only append a
// .replace() to it.
ExpressionTree arg = constructorArguments.get(0);
String replacementArg =
arg instanceof JCLiteral
? String.format(
"\"%s\"", ASTHelpers.constValue(arg, String.class).replace("_", "-"))
: String.format(
"%s.replace(\"_\", \"-\")",
state.getSourceForNode(constructorArguments.get(0)));
descriptionBuilder.addFix(
SuggestedFix.replace(tree, String.format("Locale.forLanguageTag(%s)", replacementArg)));
} else if (constructorArguments.size() == 2) {
descriptionBuilder.addFix(
SuggestedFix.replace(
tree,
String.format(
"new Locale.Builder().setLanguage(%s).setRegion(%s).build()",
state.getSourceForNode(constructorArguments.get(0)),
state.getSourceForNode(constructorArguments.get(1)))));
}
return descriptionBuilder.build();
}
return Description.NO_MATCH;
}
}