How D intercepts runtime errors

[Sean Kelly]

Serg Kovrov wrote:
> Thanks for reply, Jarrett. It is exactly what I wondering about.
> 
> * Jarrett Billingsley:
>> D, as well as most modern C++ implementations, use the underlying OS's 
>> exception handling mechanisms; on Windows, it's Structured Exception 
>> Handling (SEH), and on *nix, it's usually signals.  I'm just going to 
>> discuss SEH, as I don't know much about *nix signals, but I'd assume 
>> they are fairly similar.
> 
> Yes, I see microsoft c++ compiler has nonstandard keywords to support 
> SEH - __try and __except. But i do not have one right now to try it out. 
> In mingw/GCC's c++ compiler, on the other hand, there is no support 
> (yet, I hope) for it.
> 
> Need to say I haven't tried other c++ compilers, but GDC do not support 
> it either. And this is really sad.
> 
> Is it D language feature, or Digital Mars D compiler? Is such 
> functionality part of a language standard or standard library? It would 
> be nice if on all compiler implementations one could expect same behavior.

I think it would be useful to eventually standardize, as it would make 
throwing exceptions across dynamic library boundaries and such much more 
likely to work portably.  And I think it eventually will be.  Check the 
bottom of the ABI:

http://www.digitalmars.com/d/abi.html

For what it's worth, DMC and DMD-Win32 both use SEH for exception 
handing.  If you want to look at DMD's code for this, check 
phobos/internal/deh.c


Sean