checkclass.cpp

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

        if (! constructor_token)
        {
            // If "--style" has been given, give a warning
            if (ErrorLogger::noConstructor(_settings))
            {
                // If the class has member variables there should be an constructor
                struct VAR *varlist = ClassChecking_GetVarList(tok1);
                if (varlist)
                {
                    _errorLogger->noConstructor(_tokenizer, tok1, classNameToken->str());
                }
                // Delete the varlist..
                while (varlist)
                {
                    struct VAR *nextvar = varlist->next;
                    delete varlist;
                    varlist = nextvar;
                }
            }

            tok1 = Token::findmatch(tok1->next(), pattern_class);
            continue;
        }

        // Check that all member variables are initialized..
        struct VAR *varlist = ClassChecking_GetVarList(tok1);

        // Check constructors
        CheckConstructors(tok1, varlist, className[0]);

        // Check assignment operators
        CheckConstructors(tok1, varlist, "operator =");

        // Delete the varlist..
        while (varlist)
        {
            struct VAR *nextvar = varlist->next;
            delete varlist;
            varlist = nextvar;
        }

        tok1 = Token::findmatch(tok1->next(), pattern_class);
    }
}

void CheckClass::CheckConstructors(const Token *tok1, struct VAR *varlist, const char funcname[])
{
    const char * const className = tok1->strAt(1);

    int indentlevel = 0;
    const Token *constructor_token = FindClassFunction(tok1, className, funcname, indentlevel);
    std::list<std::string> callstack;
    ClassChecking_VarList_Initialize(tok1, constructor_token, varlist, className, callstack);
    while (constructor_token)
    {
        // Check if any variables are uninitialized
        for (struct VAR *var = varlist; var; var = var->next)
        {
            if (var->init)
                continue;

            // Is it a static member variable?
            std::ostringstream pattern;
            pattern << className << "::" << var->name << "=";
            if (Token::findmatch(_tokenizer->tokens(), pattern.str().c_str()))
                continue;

            // It's non-static and it's not initialized => error
            _errorLogger->uninitVar(_tokenizer, constructor_token, className, var->name);
        }

        for (struct VAR *var = varlist; var; var = var->next)
            var->init = false;

        constructor_token = FindClassFunction(constructor_token->next(), className, funcname, indentlevel);
        callstack.clear();
        ClassChecking_VarList_Initialize(tok1, constructor_token, varlist, className, callstack);
    }
}


//---------------------------------------------------------------------------
// ClassCheck: Unused private functions
//---------------------------------------------------------------------------

void CheckClass::privateFunctions()
{
    // Locate some class
    for (const Token *tok1 = Token::findmatch(_tokenizer->tokens(), "class %var% {"); tok1; tok1 = Token::findmatch(tok1->next(), "class %var% {"))
    {
        const std::string &classname = tok1->next()->str();

        // The class implementation must be available..
        const std::string classconstructor(classname + " :: " + classname);
        if (tok1->fileIndex() > 0 && !Token::findmatch(_tokenizer->tokens(), classconstructor.c_str()))
            continue;

        // Get private functions..
        std::list<const Token *> FuncList;
        FuncList.clear();
        bool priv = false;
        unsigned int indent_level = 0;
        for (const Token *tok = tok1; tok; tok = tok->next())
        {
            if (Token::Match(tok, "friend %var%"))
            {
                // Todo: Handle friend classes
                FuncList.clear();
                break;
            }

            if (tok->str() == "{")
                ++indent_level;
            else if (tok->str() == "}")
            {
                if (indent_level <= 1)
                    break;
                --indent_level;
            }
            else if (tok->str() == "private:")
                priv = true;
            else if (tok->str() == "public:")
                priv = false;
            else if (tok->str() == "protected:")
                priv = false;
            else if (priv && indent_level == 1)
            {
                if (Token::Match(tok, "typedef %type% ("))
                    tok = tok->tokAt(2);

                if (Token::Match(tok, "%var% (") &&
                    !Token::Match(tok, classname.c_str()))
                {
                    FuncList.push_back(tok);
                }
            }
        }

        // Check that all private functions are used..
        bool HasFuncImpl = false;
        bool inclass = false;
        indent_level = 0;
        const std::string pattern_function(classname + " ::");
        for (const Token *ftok = _tokenizer->tokens(); ftok; ftok = ftok->next())
        {
            if (ftok->str() == "{")
                ++indent_level;
            else if (ftok->str() == "}")
            {
                if (indent_level > 0)
                    --indent_level;
                if (indent_level == 0)
                    inclass = false;
            }

            if (Token::Match(ftok, ("class " + classname + " :|{").c_str()))
            {
                indent_level = 0;
                inclass = true;
            }

            // Check member class functions to see what functions are used..
            if ((inclass && indent_level == 1 && Token::Match(ftok, ") const| {")) ||
                (Token::Match(ftok, (classname + " :: ~| %var% (").c_str())))
            {
                while (ftok && ftok->str() != ")")
                    ftok = ftok->next();
                if (!ftok)
                    break;
                if (Token::Match(ftok, ") : %var% ("))
                {
                    while (!Token::Match(ftok->next(), "[{};]"))
                        ftok = ftok->next();
                }
                if (!Token::Match(ftok, ") const| {"))
                    continue;

                if (ftok->fileIndex() == 0)
                    HasFuncImpl = true;

                // Parse function..
                int indentlevel2 = 0;
                for (const Token *tok2 = ftok; tok2; tok2 = tok2->next())
                {
                    if (tok2->str() == "{")
                        ++indentlevel2;
                    else if (tok2->str() == "}")
                    {
                        --indentlevel2;
                        if (indentlevel2 < 1)
                            break;
                    }
                    else if (Token::Match(tok2, "%var% ("))
                    {
                        // Remove function from FuncList
                        for (std::list<const Token *>::iterator it = FuncList.begin(); it != FuncList.end(); ++it)
                        {
                            if (tok2->str() == (*it)->str())
                            {
                                FuncList.remove(*it);
                                break;
                            }
                        }
                    }
                }
            }
        }

        while (HasFuncImpl && !FuncList.empty())
        {
            // Final check; check if the function pointer is used somewhere..
            const std::string _pattern("return|(|)|,|= " + FuncList.front()->str());
            if (!Token::findmatch(_tokenizer->tokens(), _pattern.c_str()))
            {
                _errorLogger->unusedPrivateFunction(_tokenizer, FuncList.front(), classname, FuncList.front()->str());
            }
            FuncList.pop_front();
        }
    }
}

//---------------------------------------------------------------------------
// ClassCheck: Check that memset is not used on classes
//---------------------------------------------------------------------------

void CheckClass::noMemset()
{
    // Locate all 'memset' tokens..
    for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next())
    {
        if (!Token::Match(tok, "memset|memcpy|memmove"))
            continue;

        // Todo: Handle memcpy and memmove
        const char *type = NULL;
        if (Token::Match(tok, "memset ( %var% , %num% , sizeof ( %type% ) )"))
            type = tok->strAt(8);
        else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( %type% ) )"))
            type = tok->strAt(9);
        else if (Token::Match(tok, "memset ( %var% , %num% , sizeof ( struct %type% ) )"))
            type = tok->strAt(9);
        else if (Token::Match(tok, "memset ( & %var% , %num% , sizeof ( struct %type% ) )"))
            type = tok->strAt(10);
        else if (Token::Match(tok, "%type% ( %var% , %var% , sizeof ( %type% ) )"))
            type = tok->strAt(8);

        // No type defined => The tokens didn't match
        if (!(type && type[0]))
            continue;

        // Warn if type is a class..
        const std::string pattern1(std::string("class ") + type);
        if (Token::findmatch(_tokenizer->tokens(), pattern1.c_str()))
        {
            _errorLogger->memsetClass(_tokenizer, tok, tok->str());
            continue;
        }

        // Warn if type is a struct that contains any std::*
        const std::string pattern2(std::string("struct ") + type);
        for (const Token *tstruct = Token::findmatch(_tokenizer->tokens(), pattern2.c_str()); tstruct; tstruct = tstruct->next())
        {
            if (tstruct->str() == "}")
                break;

            if (Token::Match(tstruct, "std :: %type% %var% ;"))
            {
                _errorLogger->memsetStruct(_tokenizer, tok, tok->str(), tstruct->strAt(2));
                break;
            }
        }
    }
}
//---------------------------------------------------------------------------




//---------------------------------------------------------------------------
// ClassCheck: "void operator=("
//---------------------------------------------------------------------------

void CheckClass::operatorEq()
{
    const Token *tok = Token::findmatch(_tokenizer->tokens(), "void operator = (");
    if (tok)
    {
        _errorLogger->operatorEq(_tokenizer, tok);
    }
}
//---------------------------------------------------------------------------




//---------------------------------------------------------------------------
// A destructor in a base class should be virtual
//---------------------------------------------------------------------------

void CheckClass::virtualDestructor()
{
    const char pattern_classdecl[] = "class %var% : %var%";

    const Token *derived = _tokenizer->tokens();
    while ((derived = Token::findmatch(derived, pattern_classdecl)) != NULL)
    {
        // Check that the derived class has a non empty destructor..
        {
            std::ostringstream destructorPattern;
            destructorPattern << "~ " << derived->strAt(1) << " ( ) {";
            const Token *derived_destructor = Token::findmatch(_tokenizer->tokens(), destructorPattern.str().c_str());

            // No destructor..
            if (! derived_destructor)
            {
                derived = derived->next();
                continue;
            }

            // Empty destructor..
            if (Token::Match(derived_destructor, "~ %var% ( ) { }"))
            {
                derived = derived->next();
                continue;
            }
        }

        const Token *derivedClass = derived->tokAt(1);

        // Iterate through each base class...
        derived = derived->tokAt(3);
        while (Token::Match(derived, "%var%"))
        {
            bool isPublic = Token::Match(derived, "public");

            // What kind of inheritance is it.. public|protected|private
            if (Token::Match(derived, "public|protected|private"))
                derived = derived->next();

            // Name of base class..
            const char *baseName[2];
            baseName[0] = derived->strAt(0);
            baseName[1] = 0;

            // Update derived so it's ready for the next loop.
            derived = derived->next();
            if (Token::Match(derived, ","))
                derived = derived->next();

            // If not public inheritance, skip checking of this base class..
            if (! isPublic)
                continue;

            // Find the destructor declaration for the base class.
            const Token *base = Token::findmatch(_tokenizer->tokens(), (std::string("%any% ~ ") + baseName[0] + " (").c_str());
            while (Token::Match(base, "::"))
                base = Token::findmatch(base->next(), (std::string("%any% ~ ") + baseName[0] + + " (").c_str());

            while (Token::Match(base, "%var%") && !Token::Match(base, "virtual"))
                base = base->previous();

            // Check that there is a destructor..
            if (! base)
            {
                // Is the class declaration available?
                base = Token::findmatch(_tokenizer->tokens(), (std::string("class ") + baseName[0] + " :|{").c_str());
                if (base)
                {
                    _errorLogger->virtualDestructor(_tokenizer, base, baseName[0], derivedClass->str());
                }
            }

            // There is a destructor. Check that it's virtual..
            else if (base->str() != "virtual")
            {
                _errorLogger->virtualDestructor(_tokenizer, base, baseName[0], derivedClass->str());
            }
        }
    }
}
//---------------------------------------------------------------------------