[cfe-commits] r59232 - /cfe/trunk/lib/Analysis/GRExprEngine.cpp

[Ted Kremenek]

On Nov 13, 2008, at 4:52 PM, Zhongxing Xu wrote:

> We'll need to iterate on this one.  We may end up applying your  
> patch back, so please don't take my reverting it personally.
>
> Consider:
>
> char* p = alloca(BLOCK);
> new (p) Object1();
> ...
> new (p) Object2();
>
> Untyped memory can be recycled.  While this won't  occur that often,  
> I think with the right design we can handle such things naturally.
>
> I agree that another indirection is necessary, since:
>  - We have no type information when creating AllocaRegion.
>  - We have to attach type information to AllocaRegion.
>  - Regions are immutable once created.
>
> The question remains is that when shall we create this indirect  
> layer. A plausible time is when we have the type information, we  
> create the indirect layer.

A reasonable insertion point for such information is during VisitCast  
when the "interpretation" of a pointer changes.  We have a fair amount  
of flexibility in how we add such information because VisitCast can  
generate new GRStates.
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