C++/D interface: exceptions

[Sean Kelly via Digitalmars-d]

On Friday, 12 September 2014 at 06:56:29 UTC, Jacob Carlborg 
wrote:
> On 12/09/14 05:25, deadalnix wrote:
>
>> Yes, that is pretty why I limited myself to the "unwind 
>> properly but do
>> not catch" option. This one would require to mess with the 
>> innards of
>> various C++ runtime.
>
> On 64bit Objective-C can catch C++ exceptions. But I don't 
> think you can do anything with the exception, i.e. it uses the 
> following catch syntax:
>
> @catch(...) {}
>
> Would that be easier?

I think the trick is setting up the stack frame in such a way 
that the C++ exception mechanism knows there's a catch block 
available at all.  From there, we should be able to use the 
standard interface-to-class method to call virtual functions on 
the exception object, and hopefully the C++ runtime will handle 
cleanup for us.

I imagine the easiest thing would be to find a platform where we 
already know how exceptions are thrown in C++ (DMC on Windows?) 
and figure out how to make it work in D.  With inner functions 
and inline asm, I'm sure it's possible to make this work without 
compiler changes.  I don't know whether the unwinding mechanism 
differs across compilers or even compiler versions for a 
particular platform though.  This may all end up being a bit 
brittle.