001 /*
002 * Sonar, open source software quality management tool.
003 * Copyright (C) 2008-2011 SonarSource
004 * mailto:contact AT sonarsource DOT com
005 *
006 * Sonar is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * Sonar is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public
017 * License along with Sonar; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02
019 */
020 package org.sonar.java.ast.check;
021
022 import java.util.Arrays;
023 import java.util.List;
024 import java.util.Set;
025
026 import org.apache.commons.lang.StringUtils;
027 import org.sonar.check.Priority;
028 import org.sonar.check.Rule;
029 import org.sonar.java.ast.visitor.AstUtils;
030 import org.sonar.java.ast.visitor.JavaAstVisitor;
031 import org.sonar.java.recognizer.JavaFootprint;
032 import org.sonar.squid.api.CheckMessage;
033 import org.sonar.squid.api.SourceFile;
034 import org.sonar.squid.recognizer.CodeRecognizer;
035
036 import com.google.common.collect.Sets;
037 import com.puppycrawl.tools.checkstyle.api.DetailAST;
038 import com.puppycrawl.tools.checkstyle.api.TextBlock;
039 import com.puppycrawl.tools.checkstyle.api.TokenTypes;
040
041 /**
042 * @since 2.13
043 */
044 @Rule(key = "CommentedOutCodeLine", priority = Priority.MAJOR)
045 public class CommentedOutCodeLineCheck extends JavaAstVisitor {
046
047 private static final double THRESHOLD = 0.9;
048
049 /**
050 * This list was taken from com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocStyleCheck
051 */
052 private static final List<Integer> WANTED_TOKENS = Arrays.asList(
053 TokenTypes.INTERFACE_DEF,
054 TokenTypes.CLASS_DEF,
055 TokenTypes.ANNOTATION_DEF,
056 TokenTypes.ENUM_DEF,
057 TokenTypes.METHOD_DEF,
058 TokenTypes.CTOR_DEF,
059 TokenTypes.VARIABLE_DEF,
060 TokenTypes.ENUM_CONSTANT_DEF,
061 TokenTypes.ANNOTATION_FIELD_DEF,
062 TokenTypes.PACKAGE_DEF);
063
064 private final CodeRecognizer codeRecognizer;
065 private Set<TextBlock> comments;
066
067 public CommentedOutCodeLineCheck() {
068 codeRecognizer = new CodeRecognizer(THRESHOLD, new JavaFootprint());
069 }
070
071 @Override
072 public List<Integer> getWantedTokens() {
073 return WANTED_TOKENS;
074 }
075
076 /**
077 * Creates candidates for commented-out code - all comment blocks.
078 */
079 @Override
080 public void visitFile(DetailAST ast) {
081 comments = Sets.newHashSet();
082 for (TextBlock comment : getFileContents().getCppComments().values()) {
083 comments.add(comment);
084 }
085 for (List<TextBlock> listOfComments : getFileContents().getCComments().values()) {
086 // This list contains not only comments in C style, but also documentation comments and JSNI comments
087 comments.addAll(listOfComments);
088 }
089 }
090
091 /**
092 * Removes documentation comments and JSNI comments from candidates for commented-out code in order to prevent false-positives.
093 */
094 @Override
095 public void visitToken(DetailAST ast) {
096 if (canBeDocumented(ast)) {
097 TextBlock javadoc = getFileContents().getJavadocBefore(ast.getLineNo());
098 if (javadoc != null) {
099 comments.remove(javadoc);
100 }
101 }
102 removeJSNIComments(ast);
103 }
104
105 /**
106 * From documentation for Javadoc-tool:
107 * Documentation comments should be recognized only when placed
108 * immediately before class, interface, constructor, method, or field declarations.
109 */
110 private static boolean canBeDocumented(DetailAST ast) {
111 if (AstUtils.isType(ast, TokenTypes.VARIABLE_DEF)) {
112 return AstUtils.isClassVariable(ast);
113 }
114 return true;
115 }
116
117 /**
118 * Detects commented-out code in remaining candidates.
119 */
120 @Override
121 public void leaveFile(DetailAST ast) {
122 SourceFile sourceFile = (SourceFile) peekSourceCode();
123 for (TextBlock comment : comments) {
124 String[] lines = comment.getText();
125 for (int i = 0; i < lines.length; i++) {
126 if (codeRecognizer.isLineOfCode(lines[i])) {
127 CheckMessage message = new CheckMessage(this, "This block of commented-out lines of code should be removed.");
128 message.setLine(comment.getStartLineNo() + i);
129 sourceFile.log(message);
130 break;
131 }
132 }
133 }
134 comments = null;
135 }
136
137 /**
138 * From GWT documentation:
139 * JSNI methods are declared native and contain JavaScript code in a specially formatted comment block
140 * between the end of the parameter list and the trailing semicolon.
141 * A JSNI comment block begins with the exact token {@link #START_JSNI} and ends with the exact token {@link #END_JSNI}.
142 */
143 private void removeJSNIComments(DetailAST ast) {
144 if (AstUtils.isType(ast, TokenTypes.METHOD_DEF) && AstUtils.isModifier(ast, TokenTypes.LITERAL_NATIVE)) {
145 DetailAST endOfParameterList = ast.findFirstToken(TokenTypes.PARAMETERS).getNextSibling();
146 DetailAST trailingSemicolon = ast.getLastChild();
147
148 for (int lineNumber = endOfParameterList.getLineNo(); lineNumber <= trailingSemicolon.getLineNo(); lineNumber++) {
149 List<TextBlock> listOfComments = getFileContents().getCComments().get(lineNumber);
150 if (listOfComments != null) {
151 for (TextBlock comment : listOfComments) {
152 if (isJSNI(comment) && isCommentBetween(comment, endOfParameterList, trailingSemicolon)) {
153 comments.remove(comment);
154 }
155 }
156 }
157 }
158 }
159 }
160
161 private static boolean isCommentBetween(TextBlock comment, DetailAST start, DetailAST end) {
162 return comment.intersects(start.getLineNo(), start.getColumnNo(), end.getLineNo(), end.getColumnNo());
163 }
164
165 private static final String START_JSNI = "/*-{";
166 private static final String END_JSNI = "}-*/";
167
168 private boolean isJSNI(TextBlock comment) {
169 String[] lines = comment.getText();
170 String firstLine = lines[0];
171 String lastLine = lines[lines.length - 1];
172 return StringUtils.startsWith(firstLine, START_JSNI) && StringUtils.endsWith(lastLine, END_JSNI);
173 }
174
175 }