checkother.cpp

cppcheck is a static C/C++ code analyzer that checks for memory leaks, mismatching allocation-deallo

{
    // Walk through all tokens..
    bool func = false;
    int indentlevel = 0;
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        // Skip class and struct declarations..
        if ((tok->str() == "class") || (tok->str() == "struct"))
        {
            for (const Token *tok2 = tok; tok2; tok2 = tok2->next())
            {
                if (tok2->str() == "{")
                {
                    int indentlevel2 = 0;
                    for (tok = tok2; tok; tok = tok->next())
                    {
                        if (tok->str() == "{")
                        {
                            ++indentlevel2;
                        }
                        if (tok->str() == "}")
                        {
                            --indentlevel2;
                            if (indentlevel2 <= 0)
                            {
                                tok = tok->next();
                                break;
                            }
                        }
                    }
                    break;
                }
                if (Token::Match(tok2, "[,);]"))
                {
                    break;
                }
            }
            if (! tok)
                break;
        }

        if (tok->str() == "{")
        {
            ++indentlevel;
        }
        if (tok->str() == "}")
        {
            --indentlevel;
            if (indentlevel == 0)
                func = false;
        }
        if (indentlevel == 0 && Token::Match(tok, ") {"))
        {
            func = true;
        }
        if (indentlevel > 0 && func && Token::Match(tok, "[{};]"))
        {
            // First token of statement..
            const Token *tok1 = tok->next();
            if (! tok1)
                continue;

            if ((tok1->str() == "return") ||
                (tok1->str() == "delete") ||
                (tok1->str() == "goto") ||
                (tok1->str() == "else"))
                continue;

            // Variable declaration?
            if (Token::Match(tok1, "%var% %var% ;") ||
                Token::Match(tok1, "%var% %var% ="))
            {
                CheckVariableScope_LookupVar(tok1, tok1->strAt(1));
            }
        }
    }

}
//---------------------------------------------------------------------------

void CheckOther::CheckVariableScope_LookupVar(const Token *tok1, const char varname[])
{
    const Token *tok = tok1;

    // Skip the variable declaration..
    while (tok && !Token::Match(tok, ";"))
        tok = tok->next();

    // Check if the variable is used in this indentlevel..
    bool used = false, used1 = false;
    int indentlevel = 0;
    int parlevel = 0;
    bool for_or_while = false;
    while (indentlevel >= 0 && tok)
    {
        if (tok->str() == "{")
        {
            ++indentlevel;
        }

        else if (tok->str() == "}")
        {
            --indentlevel;
            if (indentlevel == 0)
            {
                if (for_or_while && used)
                    return;
                used1 = used;
                used = false;
            }
        }

        else if (tok->str() == "(")
        {
            ++parlevel;
        }

        else if (tok->str() == ")")
        {
            --parlevel;
        }


        else if (tok->str() == varname)
        {
            if (indentlevel == 0 || used1)
                return;
            used = true;
        }

        else if (indentlevel == 0)
        {
            if ((tok->str() == "for") || (tok->str() == "while"))
                for_or_while = true;
            if (parlevel == 0 && (tok->str() == ";"))
                for_or_while = false;
        }

        tok = tok->next();
    }

    // Warning if "used" is true
    _errorLogger->variableScope(_tokenizer, tok1, varname);
}
//---------------------------------------------------------------------------


//---------------------------------------------------------------------------
// Check for constant function parameters
//---------------------------------------------------------------------------

void CheckOther::CheckConstantFunctionParameter()
{
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        if (Token::Match(tok, "[,(] const std :: %type% %var% [,)]"))
        {
            _errorLogger->passedByValue(_tokenizer, tok, tok->strAt(5));
        }

        else if (Token::Match(tok, "[,(] const %type% %var% [,)]"))
        {
            // Check if type is a struct or class.
            const std::string pattern(std::string("class|struct ") + tok->strAt(2));
            if (Token::findmatch(_tokenizer->tokens(), pattern.c_str()))
            {
                _errorLogger->passedByValue(_tokenizer, tok, tok->strAt(3));
            }
        }
    }
}
//---------------------------------------------------------------------------


//---------------------------------------------------------------------------
// Check that all struct members are used
//---------------------------------------------------------------------------

void CheckOther::CheckStructMemberUsage()
{
    const char *structname = 0;
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        if (tok->fileIndex() != 0)
            continue;

        if (Token::Match(tok, "struct|union %type% {"))
        {
            structname = tok->strAt(1);

            // Bail out if struct/union contain any functions
            for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next())
            {
                if (tok2->str() == "(")
                {
                    structname = 0;
                    break;
                }

                if (tok2->str() == "}")
                    break;
            }
        }

        if (tok->str() == "}")
            structname = 0;

        if (structname && Token::Match(tok, "[{;]"))
        {
            const char *varname = 0;
            if (Token::Match(tok->next(), "%type% %var% [;[]"))
                varname = tok->strAt(2);
            else if (Token::Match(tok->next(), "%type% %type% %var% [;[]"))
                varname = tok->strAt(3);
            else if (Token::Match(tok->next(), "%type% * %var% [;[]"))
                varname = tok->strAt(3);
            else if (Token::Match(tok->next(), "%type% %type% * %var% [;[]"))
                varname = tok->strAt(4);
            else
                continue;

            const std::string usagePattern(". " + std::string(varname));
            bool used = false;
            for (const Token *tok2 = _tokenizer->tokens(); tok2; tok2 = tok2->next())
            {
                if (Token::simpleMatch(tok2, usagePattern.c_str()))
                {
                    used = true;
                    break;
                }
            }

            if (! used)
            {
                _errorLogger->unusedStructMember(_tokenizer, tok->next(), structname, varname);
            }
        }
    }
}





//---------------------------------------------------------------------------
// Check usage of char variables..
//---------------------------------------------------------------------------

void CheckOther::CheckCharVariable()
{
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        // Declaring the variable..
        if (Token::Match(tok, "[{};(,] signed| char %var% [;=,)]"))
        {
            // Set tok to point to the variable name
            tok = tok->tokAt(2);
            if (tok->str() == "char")
                tok = tok->next();

            // Check usage of char variable..
            int indentlevel = 0;
            for (const Token *tok2 = tok->next(); tok2; tok2 = tok2->next())
            {
                if (tok2->str() == "{")
                    ++indentlevel;

                else if (tok2->str() == "}")
                {
                    --indentlevel;
                    if (indentlevel <= 0)
                        break;
                }

                std::string temp = "%var% [ " + tok->str() + " ]";
                if ((tok2->str() != ".") && Token::Match(tok2->next(), temp.c_str()))
                {
                    _errorLogger->charArrayIndex(_tokenizer, tok2->next());
                    break;
                }

                std::string tempFirst = "%var% [&|] " + tok->str();
                std::string tempSecond = tok->str() + " [&|]";
                if (Token::Match(tok2, tempFirst.c_str()) || Token::Match(tok2, tempSecond.c_str()))
                {
                    _errorLogger->charBitOp(_tokenizer, tok2);
                    break;
                }
            }
        }
    }
}
//---------------------------------------------------------------------------






//---------------------------------------------------------------------------
// Incomplete statement..
//---------------------------------------------------------------------------

void CheckOther::CheckIncompleteStatement()
{
    int parlevel = 0;

    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        if (tok->str() == "(")
            ++parlevel;
        else if (tok->str() == ")")
            --parlevel;

        if (parlevel != 0)
            continue;

        if (Token::Match(tok, "= {"))
        {
            /* We are in an assignment, so it's not a statement.
             * Skip until ";" */

            while (!Token::Match(tok, ";"))
            {
                int level = 0;
                do
                {
                    if (tok->str() == "(" || tok->str() == "{")
                        ++level;
                    else if (tok->str() == ")" || tok->str() == "}")
                        --level;

                    tok = tok->next();

                    if (tok == NULL)
                        return;
                }
                while (level > 0);
            }

            continue;
        }

        if (Token::Match(tok, "[;{}] %str%") && !Token::Match(tok->tokAt(2), "[,}]"))
        {
            _errorLogger->constStatement(_tokenizer, tok->next(), "string");
        }

        if (Token::Match(tok, "[;{}] %num%") && !Token::Match(tok->tokAt(2), "[,}]"))
        {
            _errorLogger->constStatement(_tokenizer, tok->next(), "numeric");
        }
    }
}
//---------------------------------------------------------------------------






//---------------------------------------------------------------------------
// str plus char
//---------------------------------------------------------------------------

void CheckOther::strPlusChar()
{
    bool charVars[10000] = {0};

    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        // Declaring char variable..
        if (Token::Match(tok, "char %var% [;=]"))
        {
            unsigned int varid = tok->next()->varId();
            if (varid > 0 && varid < 10000)
                charVars[varid] = true;
        }

        //
        else if (Token::Match(tok, "[=(] %str% + %any%"))
        {
            // char constant..
            const char *s = tok->strAt(3);
            if (*s == '\'')
                _errorLogger->strPlusChar(_tokenizer, tok->next());

            // char variable..
            unsigned int varid = tok->tokAt(3)->varId();
            if (varid > 0 && varid < 10000 && charVars[varid])
                _errorLogger->strPlusChar(_tokenizer, tok->next());
        }
    }
}





void CheckOther::returnPointerToStackData()
{
    bool infunc = false;
    int indentlevel = 0;
    std::list<unsigned int> arrayVar;
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        if (!infunc && Token::simpleMatch(tok, ") {"))
        {
            infunc = true;
            indentlevel = 0;
            arrayVar.clear();
        }

        if (infunc)
        {
            if (tok->str() == "{")
                ++indentlevel;
            else if (tok->str() == "}")
            {
                --indentlevel;
                if (indentlevel <= 0)
                    infunc = false;
                continue;
            }

            // Declaring a local array..
            if (Token::Match(tok, "[;{}] %type% %var% ["))
            {
                arrayVar.push_back(tok->tokAt(2)->varId());
            }

            // Return pointer to local array variable..
            if (Token::Match(tok, "return %var% ;"))
            {
                unsigned int varid = tok->next()->varId();
                if (varid > 0 && std::find(arrayVar.begin(), arrayVar.end(), varid) != arrayVar.end())
                    _errorLogger->returnLocalVariable(_tokenizer, tok);
            }
        }

        // Declaring array variable..


    }
}