com.android.tools.lint.checks.Utf8Detector Maven / Gradle / Ivy
/*
* Copyright (C) 2012 The Android Open Source Project
*
* 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.android.tools.lint.checks;
import com.android.annotations.NonNull;
import com.android.tools.lint.detector.api.Category;
import com.android.tools.lint.detector.api.Implementation;
import com.android.tools.lint.detector.api.Issue;
import com.android.tools.lint.detector.api.Location;
import com.android.tools.lint.detector.api.ResourceXmlDetector;
import com.android.tools.lint.detector.api.Scope;
import com.android.tools.lint.detector.api.Severity;
import com.android.tools.lint.detector.api.Speed;
import com.android.tools.lint.detector.api.XmlContext;
import org.w3c.dom.Document;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Checks that the encoding used in resource files is always UTF-8
*
* TODO: Add a check which looks at files which do not specify the encoding
* and check the contents to see if it contains characters where it's ambiguous.
*/
public class Utf8Detector extends ResourceXmlDetector {
/** Detects non-utf8 encodings */
public static final Issue ISSUE = Issue.create(
"EnforceUTF8", //$NON-NLS-1$
"Encoding used in resource files is not UTF-8",
"XML supports encoding in a wide variety of character sets. However, not all " +
"tools handle the XML encoding attribute correctly, and nearly all Android " +
"apps use UTF-8, so by using UTF-8 you can protect yourself against subtle " +
"bugs when using non-ASCII characters.\n" +
"\n" +
"In particular, the Android Gradle build system will merge resource XML files " +
"assuming the resource files are using UTF-8 encoding.\n",
Category.I18N,
5,
Severity.FATAL,
new Implementation(
Utf8Detector.class,
Scope.RESOURCE_FILE_SCOPE));
/** See http://www.w3.org/TR/REC-xml/#NT-EncodingDecl */
private static final Pattern ENCODING_PATTERN =
Pattern.compile("encoding=['\"](\\S*)['\"]");//$NON-NLS-1$
/** Constructs a new {@link Utf8Detector} */
public Utf8Detector() {
}
@NonNull
@Override
public Speed getSpeed() {
return Speed.NORMAL;
}
@Override
public void visitDocument(@NonNull XmlContext context, @NonNull Document document) {
String xml = context.getContents();
if (xml == null) {
return;
}
// AAPT: The prologue must be in the first line
int lineEnd = 0;
int max = xml.length();
for (; lineEnd < max; lineEnd++) {
char c = xml.charAt(lineEnd);
if (c == '\n' || c == '\r') {
break;
}
}
for (int i = 16; i < lineEnd - 5; i++) { // +4: Skip at least