[cfe-commits] r56708 - /cfe/trunk/lib/AST/DeclGroup.cpp

[Mike Stump]

On Sep 26, 2008, at 4:19 PM, Ted Kremenek wrote:
> Use a union instead of a bunch of magic casts to implement a  
> variant.  This removes the type-punning errors for DeclGroup.

This isn't safe either.

unions are a gcc extension not sanctions by the language standard and  
they _only_ work when you have u.field1 and u.field2 in the source  
code.  The problem is you store as a Decl:

   explicit DeclGroupRef(Decl* d) : D(d) {}

then, you fetch Raw:

   Kind getKind() const { return (Kind) (Raw & Mask); }

when you call begin:

   iterator begin() {
     if (getKind() == DeclKind) return Raw ? &D : 0;

You have to fetch the same type you stored (or on of the other  
loopholes previously mentioned).