On 2006-05-01, at 09:34:21 +0100, Nick Ing-Simmons wrote:
> Vaclav Barta <[EMAIL PROTECTED]> writes:
> >Hi,
> >
> >seems rather quiet in here - anybody listening? Anyway, I've written an XS
> >module for perl 5.8.7 (Regexp::Compare, on CPAN) using regular expressions.
> >It compiles them (from caller-supplied strings) with pregcomp, and I gather
> >the compiled regexps should be released with pregfree. That works, but I'm
> >concerned about invalid values. For some inputs (i.e. '[a'), pregcomp croaks
> >and control returns to the perl caller, which is fine, except my function
> >compiles *two* regexps and when the second one croaks, it doesn't get a
> >chance to release the first... Is there some equivalent of try/catch in XS,
> >or a way to register the compiled regexp as a Perl object, to be released
> >automatically when not needed?
>
> try/catch (i.e. eval {} in perl speak) is a little tricky to do from pure XS.
> I usually call (a trivial) perl sub and use G_EVAL on the call.
There's a way to do try/catch (under certain circumstances) in XS.
If you use a recent ppport.h, it's even portable back to perl 5.003:
XCPT_TRY_START
{
risky_stuff();
}
XCPT_TRY_END
XCPT_CATCH
{
/* cleanup things here */
XCPT_RETHROW;
}
The only limitation is that you _have to_ rethrow the exception in
the catch block, i.e. you cannot catch an exception and just ignore
it. This is documented in the perlguts and perlapi manpages.
Marcus
--
With your bare hands?!?
