Any libunwind experts n da house?

[Walter Bright via Digitalmars-d]

On 9/23/2014 11:03 AM, David Nadlinger wrote:
> On Tuesday, 23 September 2014 at 17:37:42 UTC, Andrei Alexandrescu wrote:
>> We need a libunwind expert to figure out a good approach for handling
>> exceptions thrown by C++ code into D.
>>
>> Is anyone fluent with libunwind?
>
> More or less.
>
> What exactly are your goals? I thought the options we have are fairly clear, as
> discussed a few days ago. At least, Amaury and I seemed to agree (both of us
> worked on EH recently). The main question to decide is whether you want to go
> down the catch-C++-exceptions-in-D rabbit hole.

One goal is to have dmd use the g++ exception handling mechanism. But googling 
how that works, I find dead links, specs that are 15 years old accompanied by 
vague comments about it being "extended" and "look at the g++ source code", etc.

Are there any actual docs about how it works for x86? Or is it the usual "take 
apart the output of g++ and figure it out" that I usually wind up doing :-( ?