[LLVMdev] exact semantics of 'nounwind'

Chris Lattner sabre at nondot.org
Sat Mar 15 13:23:37 PDT 2008


On Mar 15, 2008, at 5:41 AM, Duncan Sands wrote:
>> We do agree that we need crystal-clear semantics in the language,  
>> so I'm
>> taking it to the mailing list to see what if we can form a consensus.
>
> the exotic part of nounwind semantics has now been removed (this was  
> that
> the nounwind attribute had to be carefully preserved and propagated  
> down
> to the codegenerators, which would put a special entry in the dwarf eh
> tables, because C++ semantic correctness was depending on the runtime
> being informed about nounwind calls), so now it can simply mean: this
> has been proved not to throw.  And if it does throw, the effect is
> undefined.

Excellent, thanks Duncan!

-Chris



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