[LLVMdev] RFC: Exception Handling Proposal II

[Renato Golin]

On 25 November 2010 02:41, John McCall <rjmccall at apple.com> wrote:
> for example, you could make the landing pad a special subclass of BasicBlock with a pointer to the dispatch, although that'd be a fairly invasive change.  Tagging the edges solves the problem for clients with a handle on an edge;  clients that want to go from (say) a dispatch to its landing pad(s) will still have trouble.

Hi John,

I think this is inevitable. To be able to represent:

bb1: unwinds to %cleanup

one has to change the behaviour of basic blocks, and the best way to
do that is to create a sub-class for that special case.

That also must be used by every optimization that analyses the call
graph, dominance, inlining, etc.

cheers,
--renato