Function valueFlowDynamicBufferSize

lib/valueflow.cpp:6911–7012

};

static void valueFlowDynamicBufferSize(const TokenList& tokenlist, const SymbolDatabase& symboldatabase, ErrorLogger& errorLogger, const Settings& settings)
{
    auto getBufferSizeFromAllocFunc = [&](const Token* funcTok) -> MathLib::bigint {
        MathLib::bigint sizeValue = -1;
        const Library::AllocFunc* allocFunc = settings.library.getAllocFuncInfo(funcTok);
        if (!allocFunc)
            allocFunc = settings.library.getReallocFuncInfo(funcTok);
        if (!allocFunc || allocFunc->bufferSize == Library::AllocFunc::BufferSize::none)
            return sizeValue;

        const std::vector<const Token*> args = getArguments(funcTok);

        const Token* const arg1 = (args.size() >= allocFunc->bufferSizeArg1) ? args[allocFunc->bufferSizeArg1 - 1] : nullptr;
        const Token* const arg2 = (args.size() >= allocFunc->bufferSizeArg2) ? args[allocFunc->bufferSizeArg2 - 1] : nullptr;

        switch (allocFunc->bufferSize) {
        case Library::AllocFunc::BufferSize::none:
            break;
        case Library::AllocFunc::BufferSize::malloc:
            if (arg1 && arg1->hasKnownIntValue())
                sizeValue = arg1->getKnownIntValue();
            break;
        case Library::AllocFunc::BufferSize::calloc:
            if (arg1 && arg2 && arg1->hasKnownIntValue() && arg2->hasKnownIntValue())
                sizeValue = arg1->getKnownIntValue() * arg2->getKnownIntValue();
            break;
        case Library::AllocFunc::BufferSize::strdup:
            if (arg1 && arg1->hasKnownValue()) {
                const ValueFlow::Value& value = arg1->values().back();
                if (value.isTokValue() && value.tokvalue->tokType() == Token::eString)
                    sizeValue = Token::getStrLength(value.tokvalue) + 1; // Add one for the null terminator
            }
            break;
        }
        return sizeValue;
    };

    auto getBufferSizeFromNew = [&](const Token* newTok) -> MathLib::bigint {
        MathLib::bigint sizeValue = -1, numElem = -1;

        if (newTok && newTok->astOperand1()) { // number of elements
            const Token* bracTok = nullptr, *typeTok = nullptr;
            if (newTok->astOperand1()->str() == "[")
                bracTok = newTok->astOperand1();
            else if (Token::Match(newTok->astOperand1(), "(|{")) {
                if (newTok->astOperand1()->astOperand1() && newTok->astOperand1()->astOperand1()->str() == "[")
                    bracTok = newTok->astOperand1()->astOperand1();
                else
                    typeTok = newTok->astOperand1()->astOperand1();
            }
            else
                typeTok = newTok->astOperand1();
            if (bracTok && bracTok->astOperand2() && bracTok->astOperand2()->hasKnownIntValue())
                numElem = bracTok->astOperand2()->getKnownIntValue();
            else if (Token::Match(typeTok, "%type%"))
                numElem = 1;
        }