[cfe-dev] Fixes for References

[Bill Wendling]

On Jul 15, 2007, at 10:28 PM, Chris Lattner wrote:
> On Jul 15, 2007, at 10:18 PM, Bill Wendling wrote:
>
>> Hi,
>>
>> This is an updated patch to fix references. It now should  
>> implement subscripted references and references to functions  
>> correctly. I believe I got all of Chris's feedback into this  
>> patch. And it has the benefit of actually working!! :-)
>
> Heh, oops, I just responded.

We crossed pathes :-)

> This patch has similar problems to the previous one.  The citation  
> [C++ 3.10p5] doesn't make sense for isLvalue, because it only  
> applies to call results.  isLvalue applies to everything.
>
> +++ Sema/SemaExpr.cpp	(working copy)
> @@ -282,10 +282,8 @@
>    Expr *LHSExp = static_cast<Expr*>(Base), *RHSExp =  
> static_cast<Expr*>(Idx);
>
>    // Perform default conversions.
> -  DefaultFunctionArrayConversion(LHSExp);
> -  DefaultFunctionArrayConversion(RHSExp);
> -
> -  QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType();
> +  QualType LHSTy = DefaultFunctionArrayConversion(LHSExp);
> +  QualType RHSTy = DefaultFunctionArrayConversion(RHSExp);
>    assert(!LHSTy.isNull() && !RHSTy.isNull() && "missing types");
>
>
> This is logically independent from the rest of the patch.  I'd like  
> to eventually remove the return value of  
> DefaultFunctionArrayConversion, so please remove this piece.

That would break the references stuff. The "stripping of the  
references" is why I made this change. Otherwise, we get a reference  
type from

   QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType();

And it fails below. If you're going to remove the return value of  
DefaultFunctionArrayConversion, then we'd have to do yet another  
stripping of the reference afterwards.

> +  if (PT == 0) {
> +    // C++ 8.5.3p1: This is a reference to a function.
> +    const ReferenceType *RT = dyn_cast<ReferenceType>(qType);
>
> This spec citation also seems wrong.  It applies to initialization  
> of references.

I'll put the correct one on when I fix the bigger problem.

-bw