////////////////////////////////////////////////////////////////////////////////
// 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.Collections;
import java.util.Set;
import java.util.stream.Collectors;
import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import com.puppycrawl.tools.checkstyle.utils.CheckUtils;
import com.puppycrawl.tools.checkstyle.utils.CommonUtils;
/**
* Check that method/constructor/catch/foreach parameters are final.
* The user can set the token set to METHOD_DEF, CONSTRUCTOR_DEF,
* LITERAL_CATCH, FOR_EACH_CLAUSE or any combination of these token
* types, to control the scope of this check.
* Default scope is both METHOD_DEF and CONSTRUCTOR_DEF.
* <p>
* Check has an option <b>ignorePrimitiveTypes</b> which allows ignoring lack of
* final modifier at
* <a href="http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html">
* primitive data type</a> parameter. Default value <b>false</b>.
* </p>
* E.g.:
* <p>
* {@code
* private void foo(int x) { ... } //parameter is of primitive type
* }
* </p>
*
* @author lkuehne
* @author o_sukhodolsky
* @author Michael Studman
* @author <a href="mailto:nesterenko-aleksey@list.ru">Aleksey Nesterenko</a>
*/
public class FinalParametersCheck extends AbstractCheck {
/**
* A key is pointing to the warning message text in "messages.properties"
* file.
*/
public static final String MSG_KEY = "final.parameter";
/**
* Contains
* <a href="http://docs.oracle.com/javase/tutorial/java/nutsandbolts/datatypes.html">
* primitive datatypes</a>.
*/
private final Set<Integer> primitiveDataTypes = Collections.unmodifiableSet(
Arrays.stream(new Integer[] {
TokenTypes.LITERAL_BYTE,
TokenTypes.LITERAL_SHORT,
TokenTypes.LITERAL_INT,
TokenTypes.LITERAL_LONG,
TokenTypes.LITERAL_FLOAT,
TokenTypes.LITERAL_DOUBLE,
TokenTypes.LITERAL_BOOLEAN,
TokenTypes.LITERAL_CHAR, })
.collect(Collectors.toSet()));
/**
* Option to ignore primitive types as params.
*/
private boolean ignorePrimitiveTypes;
/**
* Sets ignoring primitive types as params.
* @param ignorePrimitiveTypes true or false.
*/
public void setIgnorePrimitiveTypes(boolean ignorePrimitiveTypes) {
this.ignorePrimitiveTypes = ignorePrimitiveTypes;
}
@Override
public int[] getDefaultTokens() {
return new int[] {
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
};
}
@Override
public int[] getAcceptableTokens() {
return new int[] {
TokenTypes.METHOD_DEF,
TokenTypes.CTOR_DEF,
TokenTypes.LITERAL_CATCH,
TokenTypes.FOR_EACH_CLAUSE,
};
}
@Override
public int[] getRequiredTokens() {
return CommonUtils.EMPTY_INT_ARRAY;
}
@Override
public void visitToken(DetailAST ast) {
// don't flag interfaces
final DetailAST container = ast.getParent().getParent();
if (container.getType() != TokenTypes.INTERFACE_DEF) {
if (ast.getType() == TokenTypes.LITERAL_CATCH) {
visitCatch(ast);
}
else if (ast.getType() == TokenTypes.FOR_EACH_CLAUSE) {
visitForEachClause(ast);
}
else {
visitMethod(ast);
}
}
}
/**
* Checks parameters of the method or ctor.
* @param method method or ctor to check.
*/
private void visitMethod(final DetailAST method) {
final DetailAST modifiers =
method.findFirstToken(TokenTypes.MODIFIERS);
// exit on fast lane if there is nothing to check here
if (method.branchContains(TokenTypes.PARAMETER_DEF)
// ignore abstract and native methods
&& !modifiers.branchContains(TokenTypes.ABSTRACT)
&& !modifiers.branchContains(TokenTypes.LITERAL_NATIVE)) {
// we can now be sure that there is at least one parameter
final DetailAST parameters =
method.findFirstToken(TokenTypes.PARAMETERS);
DetailAST child = parameters.getFirstChild();
while (child != null) {
// children are PARAMETER_DEF and COMMA
if (child.getType() == TokenTypes.PARAMETER_DEF) {
checkParam(child);
}
child = child.getNextSibling();
}
}
}
/**
* Checks parameter of the catch block.
* @param catchClause catch block to check.
*/
private void visitCatch(final DetailAST catchClause) {
checkParam(catchClause.findFirstToken(TokenTypes.PARAMETER_DEF));
}
/**
* Checks parameter of the for each clause.
* @param forEachClause for each clause to check.
*/
private void visitForEachClause(final DetailAST forEachClause) {
checkParam(forEachClause.findFirstToken(TokenTypes.VARIABLE_DEF));
}
/**
* Checks if the given parameter is final.
* @param param parameter to check.
*/
private void checkParam(final DetailAST param) {
if (!param.branchContains(TokenTypes.FINAL) && !isIgnoredParam(param)
&& !CheckUtils.isReceiverParameter(param)) {
final DetailAST paramName = param.findFirstToken(TokenTypes.IDENT);
final DetailAST firstNode = CheckUtils.getFirstNode(param);
log(firstNode.getLineNo(), firstNode.getColumnNo(),
MSG_KEY, paramName.getText());
}
}
/**
* Checks for skip current param due to <b>ignorePrimitiveTypes</b> option.
* @param paramDef {@link TokenTypes#PARAMETER_DEF PARAMETER_DEF}
* @return true if param has to be skipped.
*/
private boolean isIgnoredParam(DetailAST paramDef) {
boolean result = false;
if (ignorePrimitiveTypes) {
final DetailAST parameterType = paramDef
.findFirstToken(TokenTypes.TYPE).getFirstChild();
if (primitiveDataTypes.contains(parameterType.getType())) {
result = true;
}
}
return result;
}
}