Method checkSignConversion

lib/checktype.cpp:254–284

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

void CheckTypeImpl::checkSignConversion()
{
    if (!mSettings.severity.isEnabled(Severity::warning))
        return;

    logChecker("CheckType::checkSignConversion"); // warning

    for (const Token *tok = mTokenizer->tokens(); tok; tok = tok->next()) {
        if (!tok->isArithmeticalOp() || Token::Match(tok,"+|-"))
            continue;

        // Is result unsigned?
        if (!(tok->valueType() && tok->valueType()->sign == ValueType::Sign::UNSIGNED))
            continue;

        // Check if an operand can be negative..
        const Token * astOperands[] = { tok->astOperand1(), tok->astOperand2() };
        for (const Token * tok1 : astOperands) {
            if (!tok1)
                continue;
            const ValueFlow::Value* negativeValue =
                ValueFlow::findValue(tok1->values(), mSettings, [&](const ValueFlow::Value& v) {
                return !v.isImpossible() && v.isIntValue() && (v.intvalue <= -1 || v.wideintvalue <= -1);
            });
            if (!negativeValue)
                continue;
            if (tok1->valueType() && tok1->valueType()->sign != ValueType::Sign::UNSIGNED)
                signConversionError(tok1, negativeValue, tok1->isNumber());
        }
    }
}

void CheckTypeImpl::signConversionError(const Token *tok, const ValueFlow::Value *negativeValue, const bool constvalue)
{