From: Daniel Jacobowitz <drow@mvista.com>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Alex Hornby <alex@anvil.com>, gcc@gcc.gnu.org
Subject: Re: GCC, GDB v6 and -fomit-frame-pointer
Date: Thu, 09 Oct 2003 12:55:00 -0000 [thread overview]
Message-ID: <20031009124208.GA31838@nevyn.them.org> (raw)
In-Reply-To: <20031009103608.GQ12344@sunsite.ms.mff.cuni.cz>
On Thu, Oct 09, 2003 at 12:36:08PM +0200, Jakub Jelinek wrote:
> On Thu, Oct 09, 2003 at 08:33:00AM -0400, Daniel Jacobowitz wrote:
> > On Thu, Oct 09, 2003 at 10:43:22AM +0100, Alex Hornby wrote:
> > >
> > > Does the new DWARF2 call frame in gdb 6.0 support mean programs compiled
> > > with GCC and -fomit-frame-pointer can now be debugged? That would be
> > > great as -fomit-frame-pointer provides quite a performance boost on x86.
> > >
> > > Assuming this is possible, what GCC and binutils versions would be
> > > needed to take advantage of this?
> >
> > In general yes. Backtraces should work. Ultra-accurate argument and
> > local variable printing requires -fvar-tracking in GCC so it's a little
> > flaky now, but unwinding should be fine.
> >
> > Anything recent. I think 3.2, 3.3 are fine.
>
> Even without CFI info? With the exception of IA-64/AMD64, GCC doesn't
> generate unwind info by default, only when -fasynchronous-unwind-tables.
Sorry, unstated assumption. This only works if you build with
debugging information. GDB parses both .eh_frame and .debug_frame, and
all the necessary CFI should be in .debug_frame with -gdwarf-2.
If debugging info bothers you, use objcopy --add-gnu-debuglink :)
--
Daniel Jacobowitz
MontaVista Software Debian GNU/Linux Developer
next prev parent reply other threads:[~2003-10-09 12:42 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-09 9:51 Alex Hornby
2003-10-09 12:39 ` Daniel Jacobowitz
2003-10-09 12:42 ` Jakub Jelinek
2003-10-09 12:55 ` Daniel Jacobowitz [this message]
2003-10-09 18:00 ` Jakub Jelinek
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