////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2017 the original author or authors.
//
// This library 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 2.1 of the License, or (at your option) any later version.
//
// This library 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 this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
////////////////////////////////////////////////////////////////////////////////
package com.puppycrawl.tools.checkstyle.checks.metrics;
import java.util.ArrayDeque;
import java.util.Deque;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
/**
* This check calculates the Non Commenting Source Statements (NCSS) metric for
* java source files and methods. The check adheres to the <a
* href="http://www.kclee.com/clemens/java/javancss">JavaNCSS specification
* </a> and gives the same results as the JavaNCSS tool.
*
* <p>The NCSS-metric tries to determine complexity of methods, classes and files
* by counting the non commenting lines. Roughly said this is (nearly)
* equivalent to counting the semicolons and opening curly braces.
*
* @author Lars Ködderitzsch
*/
// -@cs[AbbreviationAsWordInName] We can not change it as,
// check's name is a part of API (used in configurations).
public class JavaNCSSCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_METHOD = "ncss.method";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_CLASS = "ncss.class";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_FILE = "ncss.file";
/** Default constant for max file ncss. */
private static final int FILE_MAX_NCSS = 2000;
/** Default constant for max file ncss. */
private static final int CLASS_MAX_NCSS = 1500;
/** Default constant for max method ncss. */
private static final int METHOD_MAX_NCSS = 50;
/** Maximum ncss for a complete source file. */
private int fileMaximum = FILE_MAX_NCSS;
/** Maximum ncss for a class. */
private int classMaximum = CLASS_MAX_NCSS;
/** Maximum ncss for a method. */
private int methodMaximum = METHOD_MAX_NCSS;
/** List containing the stacked counters. */
private Deque<Counter> counters;
@Override
public int[] getDefaultTokens() {
return new int[] {
TokenTypes.CLASS_DEF,
TokenTypes.INTERFACE_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.PACKAGE_DEF,
TokenTypes.IMPORT,
TokenTypes.VARIABLE_DEF,
TokenTypes.CTOR_CALL,
TokenTypes.SUPER_CTOR_CALL,
TokenTypes.LITERAL_IF,
TokenTypes.LITERAL_ELSE,
TokenTypes.LITERAL_WHILE,
TokenTypes.LITERAL_DO,
TokenTypes.LITERAL_FOR,
TokenTypes.LITERAL_SWITCH,
TokenTypes.LITERAL_BREAK,
TokenTypes.LITERAL_CONTINUE,
TokenTypes.LITERAL_RETURN,
TokenTypes.LITERAL_THROW,
TokenTypes.LITERAL_SYNCHRONIZED,
TokenTypes.LITERAL_CATCH,
TokenTypes.LITERAL_FINALLY,
TokenTypes.EXPR,
TokenTypes.LABELED_STAT,
TokenTypes.LITERAL_CASE,
TokenTypes.LITERAL_DEFAULT,
};
}
@Override
public int[] getRequiredTokens() {
return new int[] {
TokenTypes.CLASS_DEF,
TokenTypes.INTERFACE_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.PACKAGE_DEF,
TokenTypes.IMPORT,
TokenTypes.VARIABLE_DEF,
TokenTypes.CTOR_CALL,
TokenTypes.SUPER_CTOR_CALL,
TokenTypes.LITERAL_IF,
TokenTypes.LITERAL_ELSE,
TokenTypes.LITERAL_WHILE,
TokenTypes.LITERAL_DO,
TokenTypes.LITERAL_FOR,
TokenTypes.LITERAL_SWITCH,
TokenTypes.LITERAL_BREAK,
TokenTypes.LITERAL_CONTINUE,
TokenTypes.LITERAL_RETURN,
TokenTypes.LITERAL_THROW,
TokenTypes.LITERAL_SYNCHRONIZED,
TokenTypes.LITERAL_CATCH,
TokenTypes.LITERAL_FINALLY,
TokenTypes.EXPR,
TokenTypes.LABELED_STAT,
TokenTypes.LITERAL_CASE,
TokenTypes.LITERAL_DEFAULT,
};
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.CLASS_DEF,
TokenTypes.INTERFACE_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.PACKAGE_DEF,
TokenTypes.IMPORT,
TokenTypes.VARIABLE_DEF,
TokenTypes.CTOR_CALL,
TokenTypes.SUPER_CTOR_CALL,
TokenTypes.LITERAL_IF,
TokenTypes.LITERAL_ELSE,
TokenTypes.LITERAL_WHILE,
TokenTypes.LITERAL_DO,
TokenTypes.LITERAL_FOR,
TokenTypes.LITERAL_SWITCH,
TokenTypes.LITERAL_BREAK,
TokenTypes.LITERAL_CONTINUE,
TokenTypes.LITERAL_RETURN,
TokenTypes.LITERAL_THROW,
TokenTypes.LITERAL_SYNCHRONIZED,
TokenTypes.LITERAL_CATCH,
TokenTypes.LITERAL_FINALLY,
TokenTypes.EXPR,
TokenTypes.LABELED_STAT,
TokenTypes.LITERAL_CASE,
TokenTypes.LITERAL_DEFAULT,
};
}
@Override
public void beginTree(DetailAST rootAST) {
counters = new ArrayDeque<>();
//add a counter for the file
counters.push(new Counter());
}
@Override
public void visitToken(DetailAST ast) {
final int tokenType = ast.getType();
if (tokenType == TokenTypes.CLASS_DEF
|| tokenType == TokenTypes.METHOD_DEF
|| tokenType == TokenTypes.CTOR_DEF
|| tokenType == TokenTypes.STATIC_INIT
|| tokenType == TokenTypes.INSTANCE_INIT) {
//add a counter for this class/method
counters.push(new Counter());
}
//check if token is countable
if (isCountable(ast)) {
//increment the stacked counters
counters.forEach(Counter::increment);
}
}
@Override
public void leaveToken(DetailAST ast) {
final int tokenType = ast.getType();
if (tokenType == TokenTypes.METHOD_DEF
|| tokenType == TokenTypes.CTOR_DEF
|| tokenType == TokenTypes.STATIC_INIT
|| tokenType == TokenTypes.INSTANCE_INIT) {
//pop counter from the stack
final Counter counter = counters.pop();
final int count = counter.getCount();
if (count > methodMaximum) {
log(ast.getLineNo(), ast.getColumnNo(), MSG_METHOD,
count, methodMaximum);
}
}
else if (tokenType == TokenTypes.CLASS_DEF) {
//pop counter from the stack
final Counter counter = counters.pop();
final int count = counter.getCount();
if (count > classMaximum) {
log(ast.getLineNo(), ast.getColumnNo(), MSG_CLASS,
count, classMaximum);
}
}
}
@Override
public void finishTree(DetailAST rootAST) {
//pop counter from the stack
final Counter counter = counters.pop();
final int count = counter.getCount();
if (count > fileMaximum) {
log(rootAST.getLineNo(), rootAST.getColumnNo(), MSG_FILE,
count, fileMaximum);
}
}
/**
* Sets the maximum ncss for a file.
*
* @param fileMaximum
* the maximum ncss
*/
public void setFileMaximum(int fileMaximum) {
this.fileMaximum = fileMaximum;
}
/**
* Sets the maximum ncss for a class.
*
* @param classMaximum
* the maximum ncss
*/
public void setClassMaximum(int classMaximum) {
this.classMaximum = classMaximum;
}
/**
* Sets the maximum ncss for a method.
*
* @param methodMaximum
* the maximum ncss
*/
public void setMethodMaximum(int methodMaximum) {
this.methodMaximum = methodMaximum;
}
/**
* Checks if a token is countable for the ncss metric.
*
* @param ast
* the AST
* @return true if the token is countable
*/
private static boolean isCountable(DetailAST ast) {
boolean countable = true;
final int tokenType = ast.getType();
//check if an expression is countable
if (tokenType == TokenTypes.EXPR) {
countable = isExpressionCountable(ast);
}
//check if an variable definition is countable
else if (tokenType == TokenTypes.VARIABLE_DEF) {
countable = isVariableDefCountable(ast);
}
return countable;
}
/**
* Checks if a variable definition is countable.
*
* @param ast the AST
* @return true if the variable definition is countable, false otherwise
*/
private static boolean isVariableDefCountable(DetailAST ast) {
boolean countable = false;
//count variable definitions only if they are direct child to a slist or
// object block
final int parentType = ast.getParent().getType();
if (parentType == TokenTypes.SLIST
|| parentType == TokenTypes.OBJBLOCK) {
final DetailAST prevSibling = ast.getPreviousSibling();
//is countable if no previous sibling is found or
//the sibling is no COMMA.
//This is done because multiple assignment on one line are counted
// as 1
countable = prevSibling == null
|| prevSibling.getType() != TokenTypes.COMMA;
}
return countable;
}
/**
* Checks if an expression is countable for the ncss metric.
*
* @param ast the AST
* @return true if the expression is countable, false otherwise
*/
private static boolean isExpressionCountable(DetailAST ast) {
final boolean countable;
//count expressions only if they are direct child to a slist (method
// body, for loop...)
//or direct child of label,if,else,do,while,for
final int parentType = ast.getParent().getType();
switch (parentType) {
case TokenTypes.SLIST :
case TokenTypes.LABELED_STAT :
case TokenTypes.LITERAL_FOR :
case TokenTypes.LITERAL_DO :
case TokenTypes.LITERAL_WHILE :
case TokenTypes.LITERAL_IF :
case TokenTypes.LITERAL_ELSE :
//don't count if or loop conditions
final DetailAST prevSibling = ast.getPreviousSibling();
countable = prevSibling == null
|| prevSibling.getType() != TokenTypes.LPAREN;
break;
default :
countable = false;
break;
}
return countable;
}
/**
* Class representing a counter.
*
* @author Lars Ködderitzsch
*/
private static class Counter {
/** The counters internal integer. */
private int count;
/**
* Increments the counter.
*/
public void increment() {
count++;
}
/**
* Gets the counters value.
*
* @return the counter
*/
public int getCount() {
return count;
}
}
}