////////////////////////////////////////////////////////////////////////////////
// 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;
import java.util.Arrays;
import java.util.Set;
import antlr.collections.AST;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
import com.puppycrawl.tools.checkstyle.utils.TokenUtils;
/**
* <p>
* Checks for restricted tokens beneath other tokens.
* </p>
* <p>
* Examples of how to configure the check:
* </p>
* <pre>
* <!-- String literal equality check -->
* <module name="DescendantToken">
* <property name="tokens" value="EQUAL,NOT_EQUAL"/>
* <property name="limitedTokens" value="STRING_LITERAL"/>
* <property name="maximumNumber" value="0"/>
* <property name="maximumDepth" value="1"/>
* </module>
*
* <!-- Switch with no default -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_SWITCH"/>
* <property name="maximumDepth" value="2"/>
* <property name="limitedTokens" value="LITERAL_DEFAULT"/>
* <property name="minimumNumber" value="1"/>
* </module>
*
* <!-- Assert statement may have side effects -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_ASSERT"/>
* <property name="limitedTokens" value="ASSIGN,DEC,INC,POST_DEC,
* POST_INC,PLUS_ASSIGN,MINUS_ASSIGN,STAR_ASSIGN,DIV_ASSIGN,MOD_ASSIGN,
* BSR_ASSIGN,SR_ASSIGN,SL_ASSIGN,BAND_ASSIGN,BXOR_ASSIGN,BOR_ASSIGN,
* METHOD_CALL"/>
* <property name="maximumNumber" value="0"/>
* </module>
*
* <!-- Initializer in for performs no setup - use while instead? -->
* <module name="DescendantToken">
* <property name="tokens" value="FOR_INIT"/>
* <property name="limitedTokens" value="EXPR"/>
* <property name="minimumNumber" value="1"/>
* </module>
*
* <!-- Condition in for performs no check -->
* <module name="DescendantToken">
* <property name="tokens" value="FOR_CONDITION"/>
* <property name="limitedTokens" value="EXPR"/>
* <property name="minimumNumber" value="1"/>
* </module>
*
* <!-- Switch within switch -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_SWITCH"/>
* <property name="limitedTokens" value="LITERAL_SWITCH"/>
* <property name="maximumNumber" value="0"/>
* <property name="minimumDepth" value="1"/>
* </module>
*
* <!-- Return from within a catch or finally block -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_FINALLY,LITERAL_CATCH"/>
* <property name="limitedTokens" value="LITERAL_RETURN"/>
* <property name="maximumNumber" value="0"/>
* </module>
*
* <!-- Try within catch or finally block -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_CATCH,LITERAL_FINALLY"/>
* <property name="limitedTokens" value="LITERAL_TRY"/>
* <property name="maximumNumber" value="0"/>
* </module>
*
* <!-- Too many cases within a switch -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_SWITCH"/>
* <property name="limitedTokens" value="LITERAL_CASE"/>
* <property name="maximumDepth" value="2"/>
* <property name="maximumNumber" value="10"/>
* </module>
*
* <!-- Too many local variables within a method -->
* <module name="DescendantToken">
* <property name="tokens" value="METHOD_DEF"/>
* <property name="limitedTokens" value="VARIABLE_DEF"/>
* <property name="maximumDepth" value="2"/>
* <property name="maximumNumber" value="10"/>
* </module>
*
* <!-- Too many returns from within a method -->
* <module name="DescendantToken">
* <property name="tokens" value="METHOD_DEF"/>
* <property name="limitedTokens" value="LITERAL_RETURN"/>
* <property name="maximumNumber" value="3"/>
* </module>
*
* <!-- Too many fields within an interface -->
* <module name="DescendantToken">
* <property name="tokens" value="INTERFACE_DEF"/>
* <property name="limitedTokens" value="VARIABLE_DEF"/>
* <property name="maximumDepth" value="2"/>
* <property name="maximumNumber" value="0"/>
* </module>
*
* <!-- Limit the number of exceptions a method can throw -->
* <module name="DescendantToken">
* <property name="tokens" value="LITERAL_THROWS"/>
* <property name="limitedTokens" value="IDENT"/>
* <property name="maximumNumber" value="1"/>
* </module>
*
* <!-- Limit the number of expressions in a method -->
* <module name="DescendantToken">
* <property name="tokens" value="METHOD_DEF"/>
* <property name="limitedTokens" value="EXPR"/>
* <property name="maximumNumber" value="200"/>
* </module>
*
* <!-- Disallow empty statements -->
* <module name="DescendantToken">
* <property name="tokens" value="EMPTY_STAT"/>
* <property name="limitedTokens" value="EMPTY_STAT"/>
* <property name="maximumNumber" value="0"/>
* <property name="maximumDepth" value="0"/>
* <property name="maximumMessage"
* value="Empty statement is not allowed."/>
* </module>
*
* <!-- Too many fields within a class -->
* <module name="DescendantToken">
* <property name="tokens" value="CLASS_DEF"/>
* <property name="limitedTokens" value="VARIABLE_DEF"/>
* <property name="maximumDepth" value="2"/>
* <property name="maximumNumber" value="10"/>
* </module>
* </pre>
*
* @author Tim Tyler <tim@tt1.org>
* @author Rick Giles
*/
public class DescendantTokenCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY_MIN = "descendant.token.min";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY_MAX = "descendant.token.max";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY_SUM_MIN = "descendant.token.sum.min";
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY_SUM_MAX = "descendant.token.sum.max";
/** Minimum depth. */
private int minimumDepth;
/** Maximum depth. */
private int maximumDepth = Integer.MAX_VALUE;
/** Minimum number. */
private int minimumNumber;
/** Maximum number. */
private int maximumNumber = Integer.MAX_VALUE;
/** Whether to sum the number of tokens found. */
private boolean sumTokenCounts;
/** Limited tokens. */
private int[] limitedTokens = CommonUtils.EMPTY_INT_ARRAY;
/** Error message when minimum count not reached. */
private String minimumMessage;
/** Error message when maximum count exceeded. */
private String maximumMessage;
/**
* Counts of descendant tokens.
* Indexed by (token ID - 1) for performance.
*/
private int[] counts = CommonUtils.EMPTY_INT_ARRAY;
@Override
public int[] getDefaultTokens() {
return CommonUtils.EMPTY_INT_ARRAY;
}
@Override
public int[] getRequiredTokens() {
return CommonUtils.EMPTY_INT_ARRAY;
}
@Override
public void visitToken(DetailAST ast) {
//reset counts
Arrays.fill(counts, 0);
countTokens(ast, 0);
if (sumTokenCounts) {
logAsTotal(ast);
}
else {
logAsSeparated(ast);
}
}
/**
* Log violations for each Token.
* @param ast token
*/
private void logAsSeparated(DetailAST ast) {
// name of this token
final String name = TokenUtils.getTokenName(ast.getType());
for (int element : limitedTokens) {
final int tokenCount = counts[element - 1];
if (tokenCount < minimumNumber) {
final String descendantName = TokenUtils.getTokenName(element);
if (minimumMessage == null) {
minimumMessage = MSG_KEY_MIN;
}
log(ast.getLineNo(), ast.getColumnNo(),
minimumMessage,
String.valueOf(tokenCount),
String.valueOf(minimumNumber),
name,
descendantName);
}
if (tokenCount > maximumNumber) {
final String descendantName = TokenUtils.getTokenName(element);
if (maximumMessage == null) {
maximumMessage = MSG_KEY_MAX;
}
log(ast.getLineNo(), ast.getColumnNo(),
maximumMessage,
String.valueOf(tokenCount),
String.valueOf(maximumNumber),
name,
descendantName);
}
}
}
/**
* Log validation as one violation.
* @param ast current token
*/
private void logAsTotal(DetailAST ast) {
// name of this token
final String name = TokenUtils.getTokenName(ast.getType());
int total = 0;
for (int element : limitedTokens) {
total += counts[element - 1];
}
if (total < minimumNumber) {
if (minimumMessage == null) {
minimumMessage = MSG_KEY_SUM_MIN;
}
log(ast.getLineNo(), ast.getColumnNo(),
minimumMessage,
String.valueOf(total),
String.valueOf(minimumNumber), name);
}
if (total > maximumNumber) {
if (maximumMessage == null) {
maximumMessage = MSG_KEY_SUM_MAX;
}
log(ast.getLineNo(), ast.getColumnNo(),
maximumMessage,
String.valueOf(total),
String.valueOf(maximumNumber), name);
}
}
/**
* Counts the number of occurrences of descendant tokens.
* @param ast the root token for descendants.
* @param depth the maximum depth of the counted descendants.
*/
private void countTokens(AST ast, int depth) {
if (depth <= maximumDepth) {
//update count
if (depth >= minimumDepth) {
final int type = ast.getType();
if (type <= counts.length) {
counts[type - 1]++;
}
}
AST child = ast.getFirstChild();
final int nextDepth = depth + 1;
while (child != null) {
countTokens(child, nextDepth);
child = child.getNextSibling();
}
}
}
@Override
public int[] getAcceptableTokens() {
// Any tokens set by property 'tokens' are acceptable
final Set<String> tokenNames = getTokenNames();
final int[] result = new int[tokenNames.size()];
int index = 0;
for (String name : tokenNames) {
result[index] = TokenUtils.getTokenId(name);
index++;
}
return result;
}
/**
* Sets the tokens which occurrence as descendant is limited.
* @param limitedTokensParam - list of tokens to ignore.
*/
public void setLimitedTokens(String... limitedTokensParam) {
limitedTokens = new int[limitedTokensParam.length];
int maxToken = 0;
for (int i = 0; i < limitedTokensParam.length; i++) {
limitedTokens[i] = TokenUtils.getTokenId(limitedTokensParam[i]);
if (limitedTokens[i] > maxToken) {
maxToken = limitedTokens[i];
}
}
counts = new int[maxToken];
}
/**
* Sets the minimum depth for descendant counts.
* @param minimumDepth the minimum depth for descendant counts.
*/
public void setMinimumDepth(int minimumDepth) {
this.minimumDepth = minimumDepth;
}
/**
* Sets the maximum depth for descendant counts.
* @param maximumDepth the maximum depth for descendant counts.
*/
public void setMaximumDepth(int maximumDepth) {
this.maximumDepth = maximumDepth;
}
/**
* Sets a minimum count for descendants.
* @param minimumNumber the minimum count for descendants.
*/
public void setMinimumNumber(int minimumNumber) {
this.minimumNumber = minimumNumber;
}
/**
* Sets a maximum count for descendants.
* @param maximumNumber the maximum count for descendants.
*/
public void setMaximumNumber(int maximumNumber) {
this.maximumNumber = maximumNumber;
}
/**
* Sets the error message for minimum count not reached.
* @param message the error message for minimum count not reached.
* Used as a {@code MessageFormat} pattern with arguments
* <ul>
* <li>{0} - token count</li>
* <li>{1} - minimum number</li>
* <li>{2} - name of token</li>
* <li>{3} - name of limited token</li>
* </ul>
*/
public void setMinimumMessage(String message) {
minimumMessage = message;
}
/**
* Sets the error message for maximum count exceeded.
* @param message the error message for maximum count exceeded.
* Used as a {@code MessageFormat} pattern with arguments
* <ul>
* <li>{0} - token count</li>
* <li>{1} - maximum number</li>
* <li>{2} - name of token</li>
* <li>{3} - name of limited token</li>
* </ul>
*/
public void setMaximumMessage(String message) {
maximumMessage = message;
}
/**
* Sets whether to use the sum of the tokens found, rather than the
* individual counts.
* @param sum whether to use the sum.
*/
public void setSumTokenCounts(boolean sum) {
sumTokenCounts = sum;
}
}