cppcheck/lib/checkpostfixoperator.cpp

/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2010 Daniel Marjamäki and Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

//---------------------------------------------------------------------------
// You should use ++ and -- as prefix whenever possible as these are more 
// efficient than postfix operators
//---------------------------------------------------------------------------

#include "checkpostfixoperator.h"

//---------------------------------------------------------------------------


// Register this check class (by creating a static instance of it)
namespace
{
CheckPostfixOperator instance;
}

void CheckPostfixOperator::postfixOperator()
{
    if (!_settings->_checkCodingStyle)
        return;

    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        bool result = false;
        if ( Token::Match(tok, "++|--") ) {
	    if ( Token::Match(tok->previous()->previous(), ";|{|}") && Token::Match(tok->next(), ";|)|,") ) {
	  	result = true; 
	    }
	    else if (tok->strAt(-2) == ",") {
		int i(1);
		while(tok->strAt(i) != ")") {
			if(tok->strAt(i) == ";") {
				result = true;
				break;
			}
			++i;
		}
            }
	    else if (tok->strAt(-2) == "<<" && tok->strAt(1) == "<<") {
	        result = true;
	    }
        }

        if(result) {
             const Token *decltok = Token::findmatch(_tokenizer->tokens(), "%varid%", tok->previous()->varId());
             if (decltok && Token::Match(decltok->previous(), "iterator|const_iterator|reverse_iterator|const_reverse_iterator")) {
                 // the variable is an iterator
                 postfixOperatorError(tok);
             }
             else { 
                 const std::string classDef = std::string("class ") + std::string(decltok->previous()->strAt(0));
                 if (Token::findmatch(_tokenizer->tokens(), classDef.c_str())) {
                     // the variable is an instance of class
                     postfixOperatorError(tok);
                 }
            }
        }
    }
}
//---------------------------------------------------------------------------


void CheckPostfixOperator::postfixOperatorError(const Token *tok)
{
    reportError(tok, Severity::style, "postfixOperator", "You should use ++ and -- as prefix whenever possible as these are more efficient than postfix operators");
}