[cfe-dev] static_cast and dynamic_cast semantic checks

[Doug Gregor]

On Thu, Oct 30, 2008 at 11:19 AM, Sebastian Redl
<sebastian.redl at getdesigned.at> wrote:
> Doug Gregor wrote:
>> +  // C++ 5.2.7p5
>> +  // Upcasts are resolved statically.
>> +  if (DestRecord && IsDerivedFrom(SrcPointee, DestPointee)) {
>> +    CheckDerivedToBaseConversion(SrcPointee, DestPointee, OpLoc,
>> SourceRange());
>> +    // Diagnostic already emitted on error.
>> +    return;
>> +  }
>>
>> Shouldn't the last argument to CheckDerivedToBaseConversion be the
>> source range containing the full static_cast expression?
>>
>
> Could be. On the other hand, I never mark the entire cast expression on
> conversion errors that involve both source and destination, so it would be a
> bit inconsistent.

Hmmm... actually, I think I'd prefer if errors that involve both
source and destination always marked the whole cast expression. It
doesn't matter much in a terminal, but in an IDE it would be really
nice for the whole erroneous express to be marked.

>>
>>  bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType
>> ToType)
>>  {
>>   const BuiltinType *To = ToType->getAsBuiltinType();
>> +  if (!To) {
>> +    return false;
>> +  }
>>
>>   // An rvalue of type char, signed char, unsigned char, short int, or
>>   // unsigned short int can be converted to an rvalue of type int if
>>   // int can represent all the values of the source type; otherwise,
>>   // the source rvalue can be converted to an rvalue of type unsigned
>>   // int (C++ 4.5p1).
>> -  if (FromType->isPromotableIntegerType() &&
>> !FromType->isBooleanType() && To) {
>> +  if (FromType->isPromotableIntegerType() && !FromType->isBooleanType())
>> {
>>
>> You only need the top change or the bottom change, not both; I suggest
>> keeping the top one.
>>
>
> You seem to have this backward. There's a check for To not being null in
> your existing code. Since my newly introduced check assures this, I removed
> yours.

Yep, you're right. Thanks!

  - Doug