Re: Reducing debug info for C++ ctors/dtors

[Devang Patel <dpatel at apple dot com>]

On Jul 11, 2005, at 6:18 PM, Daniel Jacobowitz wrote:

> On Mon, Jul 11, 2005 at 06:11:58PM -0700, Jason Molenda wrote:
>
> > Yeah, Devang didn't present what we're doing here on the debug side
> > too well.  We're giving up a bit of information from within gdb --
> > it won't know what constructors and destructors a class has defined
> > -- for a large savings in debug info (this can be over 20% of an
> > application's debug info when lots of templates are in heavy use).
> >
> > Because the FUN stabs are still present, gdb knows about the
> > constructors; it can step into them, it can set breakpoints on them.
> >
> > For most developers, this isn't a worthwhile tradeoff, but for a
> > certain class of appliations the stabs debug info is enormous and
> > this helps to ameloriate that by giving up a small bit of gdb
> > functionality.  This won't be enabled by default even within Apple,
> > but it is a useful option to have available.
>
> Thanks for the explanation.  That makes more sense.

What do others think about this patch? If people think, it is OK
to have one additional knob for users then I'll test and submit
formal patch.

I'll treat silence as, this idea is not OK for FSF GCC. I'd like to
give Jason and our customers compiler with such fix ASAP. And if
it is considered good idea for FSF GCC then I'd like to iron out
small details (e.g. name of switch, stabs specific or general for
all dbg format etc..), in the beginning.


Thanks,
-
Devang