org.sonar.java.ast.check.CommentedOutCodeLineCheck Maven / Gradle / Ivy
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/*
* Sonar, open source software quality management tool.
* Copyright (C) 2008-2012 SonarSource
* mailto:contact AT sonarsource DOT com
*
* Sonar is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 3 of the License, or (at your option) any later version.
*
* Sonar is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Sonar; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02
*/
package org.sonar.java.ast.check;
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TextBlock;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import org.apache.commons.lang.StringUtils;
import org.sonar.check.BelongsToProfile;
import org.sonar.check.Priority;
import org.sonar.check.Rule;
import org.sonar.java.ast.visitor.AstUtils;
import org.sonar.java.ast.visitor.JavaAstVisitor;
import org.sonar.java.recognizer.JavaFootprint;
import org.sonar.squid.api.CheckMessage;
import org.sonar.squid.api.SourceFile;
import org.sonar.squid.recognizer.CodeRecognizer;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Set;
/**
* @since 2.13
*/
@Rule(key = "CommentedOutCodeLine", priority = Priority.MAJOR)
@BelongsToProfile(title = "Sonar way", priority = Priority.MAJOR)
public class CommentedOutCodeLineCheck extends JavaAstVisitor {
private static final double THRESHOLD = 0.9;
/**
* This list was taken from com.puppycrawl.tools.checkstyle.checks.javadoc.JavadocStyleCheck
*/
private static final List WANTED_TOKENS = Arrays.asList(
TokenTypes.INTERFACE_DEF,
TokenTypes.CLASS_DEF,
TokenTypes.ANNOTATION_DEF,
TokenTypes.ENUM_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
TokenTypes.VARIABLE_DEF,
TokenTypes.ENUM_CONSTANT_DEF,
TokenTypes.ANNOTATION_FIELD_DEF,
TokenTypes.PACKAGE_DEF);
private final CodeRecognizer codeRecognizer;
private Set comments;
public CommentedOutCodeLineCheck() {
codeRecognizer = new CodeRecognizer(THRESHOLD, new JavaFootprint());
}
@Override
public List getWantedTokens() {
return WANTED_TOKENS;
}
/**
* Creates candidates for commented-out code - all comment blocks.
*/
@Override
public void visitFile(DetailAST ast) {
comments = Sets.newHashSet();
for (TextBlock comment : getFileContents().getCppComments().values()) {
comments.add(comment);
}
for (List listOfComments : getFileContents().getCComments().values()) {
// This list contains not only comments in C style, but also documentation comments and JSNI comments
for (TextBlock comment : listOfComments) {
if (!isHeader(comment)) {
comments.addAll(listOfComments);
}
}
}
}
/**
* We assume that comment on a first line - is a header with license.
* However possible to imagine corner case: file may contain commented-out code starting from first line.
* But we assume that probability of this is really low.
*/
private static boolean isHeader(TextBlock comment) {
return comment.getStartLineNo() == 1;
}
/**
* Removes documentation comments and JSNI comments from candidates for commented-out code in order to prevent false-positives.
*/
@Override
public void visitToken(DetailAST ast) {
if (canBeDocumented(ast)) {
TextBlock javadoc = getFileContents().getJavadocBefore(ast.getLineNo());
if (javadoc != null) {
comments.remove(javadoc);
}
}
removeJSNIComments(ast);
}
/**
* From documentation for Javadoc-tool:
* Documentation comments should be recognized only when placed
* immediately before class, interface, constructor, method, or field declarations.
*/
private static boolean canBeDocumented(DetailAST ast) {
if (AstUtils.isType(ast, TokenTypes.VARIABLE_DEF)) {
return AstUtils.isClassVariable(ast);
}
return true;
}
/**
* Detects commented-out code in remaining candidates.
*/
@Override
public void leaveFile(DetailAST ast) {
List commentedOutCodeLines = Lists.newArrayList();
for (TextBlock comment : comments) {
String[] lines = comment.getText();
for (int i = 0; i < lines.length; i++) {
if (codeRecognizer.isLineOfCode(lines[i])) {
// Mark all remaining lines from this comment as a commented out lines of code
for (int j = i; j < lines.length; j++) {
commentedOutCodeLines.add(comment.getStartLineNo() + j);
}
break;
}
}
}
// Greedy algorithm to split lines on blocks and to report only one violation per block
SourceFile sourceFile = (SourceFile) peekSourceCode();
Collections.sort(commentedOutCodeLines);
int prev = Integer.MIN_VALUE;
for (int i = 0; i < commentedOutCodeLines.size(); i++) {
int current = commentedOutCodeLines.get(i);
if (prev + 1 < current) {
CheckMessage message = new CheckMessage(this, "This block of commented-out lines of code should be removed.");
message.setLine(current);
sourceFile.log(message);
}
prev = current;
}
comments = null;
}
/**
* From GWT documentation:
* JSNI methods are declared native and contain JavaScript code in a specially formatted comment block
* between the end of the parameter list and the trailing semicolon.
* A JSNI comment block begins with the exact token {@link #START_JSNI} and ends with the exact token {@link #END_JSNI}.
*/
private void removeJSNIComments(DetailAST ast) {
if (AstUtils.isType(ast, TokenTypes.METHOD_DEF) && AstUtils.isModifier(ast, TokenTypes.LITERAL_NATIVE)) {
DetailAST endOfParameterList = ast.findFirstToken(TokenTypes.PARAMETERS).getNextSibling();
DetailAST trailingSemicolon = ast.getLastChild();
for (int lineNumber = endOfParameterList.getLineNo(); lineNumber <= trailingSemicolon.getLineNo(); lineNumber++) {
List listOfComments = getFileContents().getCComments().get(lineNumber);
if (listOfComments != null) {
for (TextBlock comment : listOfComments) {
if (isJSNI(comment) && isCommentBetween(comment, endOfParameterList, trailingSemicolon)) {
comments.remove(comment);
}
}
}
}
}
}
private static boolean isCommentBetween(TextBlock comment, DetailAST start, DetailAST end) {
return comment.intersects(start.getLineNo(), start.getColumnNo(), end.getLineNo(), end.getColumnNo());
}
private static final String START_JSNI = "/*-{";
private static final String END_JSNI = "}-*/";
private boolean isJSNI(TextBlock comment) {
String[] lines = comment.getText();
String firstLine = lines[0];
String lastLine = lines[lines.length - 1];
return StringUtils.startsWith(firstLine, START_JSNI) && StringUtils.endsWith(lastLine, END_JSNI);
}
}
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