[cxx-abi-dev] ABI modification for exception propagation

[Mark Mitchell]

Sebastian Redl wrote:

> I experimentally implemented N2197 "Exception Propagation" in GCC and 
> came to the conclusion that the current exception handling ABI 
> specification is insufficient. It needs to be changed in order to make 
> exception propagation possible.

Do you have a URL for this paper?

> I wrote up a proposal for the changes. My current implementation doesn't 
> quite follow this proposal, since I came up with some of the ideas while 
> writing the document, but I will change it.

It looks like your proposal is not backwards-compatible with the current 
ABI.  I think we should try very hard to avoid breaking compatibility. 
If that means that we need to create new functions (like 
__cxa_throw_exception_0x) or accept some performance tradeoffs, we 
should do so.  But, it should be possible to link old C++ binaries with 
the new C++ library, and, ideally, to mix object files from old and new 
versions of C++ and the run-time library.

Thanks,

-- 
Mark Mitchell
CodeSourcery
mark at codesourcery.com
(650) 331-3385 x713