////////////////////////////////////////////////////////////////////////////////
// checkstyle: Checks Java source code for adherence to a set of rules.
// Copyright (C) 2001-2008 Oliver Burn
//
// 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.coding;
import com.puppycrawl.tools.checkstyle.api.Check;
import com.puppycrawl.tools.checkstyle.api.DetailAST;
import com.puppycrawl.tools.checkstyle.api.FastStack;
import com.puppycrawl.tools.checkstyle.api.ScopeUtils;
import com.puppycrawl.tools.checkstyle.api.TokenTypes;
import java.util.HashMap;
import java.util.Map;
/**
* <p>
* Ensures that local variables that never get their values changed,
* must be declared final.
* </p>
* <p>
* An example of how to configure the check is:
* </p>
* <pre>
* <module name="FinalLocalVariable">
* <property name="token" value="VARIABLE_DEF"/>
* </module>
* </pre>
* @author k_gibbs, r_auckenthaler
*/
public class FinalLocalVariableCheck extends Check
{
/** Scope Stack */
private final FastStack<Map<String, DetailAST>> mScopeStack =
FastStack.newInstance();
@Override
public int[] getDefaultTokens()
{
return new int[] {
TokenTypes.IDENT,
TokenTypes.CTOR_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.VARIABLE_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.LITERAL_FOR,
TokenTypes.SLIST,
TokenTypes.OBJBLOCK,
};
}
@Override
public int[] getAcceptableTokens()
{
return new int[] {
TokenTypes.VARIABLE_DEF,
TokenTypes.PARAMETER_DEF,
};
}
@Override
public int[] getRequiredTokens()
{
return new int[] {
TokenTypes.IDENT,
TokenTypes.CTOR_DEF,
TokenTypes.METHOD_DEF,
TokenTypes.INSTANCE_INIT,
TokenTypes.STATIC_INIT,
TokenTypes.LITERAL_FOR,
TokenTypes.SLIST,
TokenTypes.OBJBLOCK,
};
}
@Override
public void visitToken(DetailAST aAST)
{
switch(aAST.getType()) {
case TokenTypes.OBJBLOCK:
case TokenTypes.SLIST:
case TokenTypes.LITERAL_FOR:
case TokenTypes.METHOD_DEF:
case TokenTypes.CTOR_DEF:
case TokenTypes.STATIC_INIT:
case TokenTypes.INSTANCE_INIT:
mScopeStack.push(new HashMap<String, DetailAST>());
break;
case TokenTypes.PARAMETER_DEF:
if (ScopeUtils.inInterfaceBlock(aAST)
|| inAbstractMethod(aAST))
{
break;
}
case TokenTypes.VARIABLE_DEF:
if ((aAST.getParent().getType() != TokenTypes.OBJBLOCK)
&& (aAST.getParent().getType() != TokenTypes.FOR_EACH_CLAUSE))
{
insertVariable(aAST);
}
break;
case TokenTypes.IDENT:
final int parentType = aAST.getParent().getType();
if ((TokenTypes.POST_DEC == parentType)
|| (TokenTypes.DEC == parentType)
|| (TokenTypes.POST_INC == parentType)
|| (TokenTypes.INC == parentType)
|| (TokenTypes.ASSIGN == parentType)
|| (TokenTypes.PLUS_ASSIGN == parentType)
|| (TokenTypes.MINUS_ASSIGN == parentType)
|| (TokenTypes.DIV_ASSIGN == parentType)
|| (TokenTypes.STAR_ASSIGN == parentType)
|| (TokenTypes.MOD_ASSIGN == parentType)
|| (TokenTypes.SR_ASSIGN == parentType)
|| (TokenTypes.BSR_ASSIGN == parentType)
|| (TokenTypes.SL_ASSIGN == parentType)
|| (TokenTypes.BXOR_ASSIGN == parentType)
|| (TokenTypes.BOR_ASSIGN == parentType)
|| (TokenTypes.BAND_ASSIGN == parentType))
{
// TODO: is there better way to check is aAST
// in left part of assignment?
if (aAST.getParent().getFirstChild() == aAST) {
removeVariable(aAST);
}
}
break;
default:
}
}
/**
* Determines whether an AST is a descentant of an abstract method.
* @param aAST the AST to check.
* @return true if aAST is a descentant of an abstract method.
*/
private boolean inAbstractMethod(DetailAST aAST)
{
DetailAST parent = aAST.getParent();
while (parent != null) {
if (parent.getType() == TokenTypes.METHOD_DEF) {
final DetailAST modifiers =
parent.findFirstToken(TokenTypes.MODIFIERS);
return modifiers.branchContains(TokenTypes.ABSTRACT);
}
parent = parent.getParent();
}
return false;
}
/**
* Inserts a variable at the topmost scope stack
* @param aAST the variable to insert
*/
private void insertVariable(DetailAST aAST)
{
if (!aAST.branchContains(TokenTypes.FINAL)) {
final Map<String, DetailAST> state = mScopeStack.peek();
final DetailAST ast = aAST.findFirstToken(TokenTypes.IDENT);
state.put(ast.getText(), ast);
}
}
/**
* Removes the variable from the Stacks
* @param aAST Variable to remove
*/
private void removeVariable(DetailAST aAST)
{
for (int i = mScopeStack.size() - 1; i >= 0; i--) {
final Map<String, DetailAST> state = mScopeStack.peek(i);
final Object obj = state.remove(aAST.getText());
if (obj != null) {
break;
}
}
}
@Override
public void leaveToken(DetailAST aAST)
{
super.leaveToken(aAST);
switch(aAST.getType()) {
case TokenTypes.OBJBLOCK:
case TokenTypes.SLIST:
case TokenTypes.LITERAL_FOR:
case TokenTypes.CTOR_DEF:
case TokenTypes.STATIC_INIT:
case TokenTypes.INSTANCE_INIT:
case TokenTypes.METHOD_DEF:
final Map<String, DetailAST> state = mScopeStack.pop();
for (DetailAST var : state.values()) {
log(var.getLineNo(), var.getColumnNo(), "final.variable", var
.getText());
}
break;
default:
}
}
}