com.google.errorprone.bugpatterns.PreconditionsInvalidPlaceholder Maven / Gradle / Ivy
/*
* Copyright 2012 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.ERROR;
import static com.google.errorprone.matchers.Matchers.allOf;
import static com.google.errorprone.matchers.Matchers.anyOf;
import static com.google.errorprone.matchers.Matchers.staticMethod;
import static com.google.errorprone.util.ASTHelpers.getSymbol;
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.MethodInvocationTreeMatcher;
import com.google.errorprone.fixes.SuggestedFix;
import com.google.errorprone.matchers.Description;
import com.google.errorprone.matchers.Matcher;
import com.sun.source.tree.ExpressionTree;
import com.sun.source.tree.LiteralTree;
import com.sun.source.tree.MethodInvocationTree;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.code.Symbol.MethodSymbol;
import java.util.regex.Pattern;
/**
* @author Louis Wasserman
*/
@BugPattern(
summary = "Preconditions only accepts the %s placeholder in error message strings",
severity = ERROR,
tags = StandardTags.LIKELY_ERROR)
public class PreconditionsInvalidPlaceholder extends BugChecker
implements MethodInvocationTreeMatcher {
private static final Matcher PRECONDITIONS_CHECK =
allOf(
anyOf(
staticMethod().onClass("com.google.common.base.Preconditions"),
staticMethod().onClass("com.google.common.base.Verify")),
PreconditionsInvalidPlaceholder::secondParameterIsString);
private static boolean secondParameterIsString(ExpressionTree tree, VisitorState state) {
Symbol symbol = getSymbol(tree);
if (!(symbol instanceof MethodSymbol)) {
return false;
}
MethodSymbol methodSymbol = (MethodSymbol) symbol;
return methodSymbol.getParameters().size() >= 2
&& isSubtype(methodSymbol.getParameters().get(1).type, state.getSymtab().stringType, state);
}
@Override
public Description matchMethodInvocation(MethodInvocationTree tree, VisitorState state) {
if (PRECONDITIONS_CHECK.matches(tree, state)
&& tree.getArguments().get(1) instanceof LiteralTree) {
LiteralTree formatStringTree = (LiteralTree) tree.getArguments().get(1);
if (formatStringTree.getValue() instanceof String) {
String formatString = (String) formatStringTree.getValue();
int expectedArgs = expectedArguments(formatString);
if (expectedArgs < tree.getArguments().size() - 2
&& BAD_PLACEHOLDER_REGEX.matcher(formatString).find()) {
return describe(tree, state);
}
}
}
return Description.NO_MATCH;
}
/**
* Matches most {@code java.util.Formatter} and {@code java.text.MessageFormat} format
* placeholders, other than %s itself.
*
* This does not need to be completely exhaustive, since it is only used to suggest fixes.
*/
private static final Pattern BAD_PLACEHOLDER_REGEX =
Pattern.compile("\\$s|%(?:\\d+\\$)??[dbBhHScCoxXeEfgGaAtTn]|\\{\\d+}");
public Description describe(MethodInvocationTree tree, VisitorState state) {
LiteralTree formatTree = (LiteralTree) tree.getArguments().get(1);
String fixedFormatString =
BAD_PLACEHOLDER_REGEX.matcher(state.getSourceForNode(formatTree)).replaceAll("%s");
if (expectedArguments(fixedFormatString) == tree.getArguments().size() - 2) {
return describeMatch(formatTree, SuggestedFix.replace(formatTree, fixedFormatString));
}
int missing = tree.getArguments().size() - 2 - expectedArguments(fixedFormatString);
StringBuilder builder = new StringBuilder(fixedFormatString);
builder.deleteCharAt(builder.length() - 1);
builder.append(" [%s");
for (int i = 1; i < missing; i++) {
builder.append(", %s");
}
builder.append("]\"");
return describeMatch(tree, SuggestedFix.replace(formatTree, builder.toString()));
}
private static int expectedArguments(String formatString) {
int count = 0;
for (int i = formatString.indexOf("%s"); i != -1; i = formatString.indexOf("%s", i + 1)) {
count++;
}
return count;
}
}