Re: HP-PA ABI issues - framepointer handling

[Alex Hornby <alex at anvil dot co dot uk>]

Robert Dewar writes:
 > 
 > Well it seems quite a legitimate part of the ABI to me to specify where
 > the old frame pointer is stored. I agree the definition is stupid from
 > a performance point of view, but I don't see that it is inappropriate
 > as part of the ABI.
 > 
 > I do not think gcc should casually depart from the ABI in this case, if
 > there is a performance issue, then it is reasonable to have a special
 > switch to generate non-standard code.
 > 
 > I do not see that it is easy to do proper stack unwinding in mixed gcc
 > and non-gcc code without depending on the "lame unwinder". Note that
 > as far as we know, g++ on HPUX is using longjmp/setjump for exception
 > management -- is that understanding correct?
 > 
 > It has always been a strength of gcc that for the most part it obeys
 > system standards and in particular published ABI's. I think this same
 > standard should be followed for HPUX unless there is a very good reason
 > not to do so.

For what its worth as someone occasionally using GCC on HP-UX, I'd
rather have ABI compliance by default, with options to get better
performance if necessary.

Is this the cause of the g++ problems with exceptions thrown from
shared libraries on HP-UX?

Regards,
Alex.