Re: info frame

[Mark Kettenis <mark.kettenis@xs4all.nl>]

> X-Spam-Checker-Version: SpamAssassin 3.1.0 (2005-09-13) on 
> 	elgar.sibelius.xs4all.nl
> X-Spam-Level: 
> X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=failed 
> 	version=3.1.0
> Date: Mon, 17 Apr 2006 13:35:54 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> CC: nickrob@snap.net.nz, gdb@sources.redhat.com
> Reply-to: Eli Zaretskii <eliz@gnu.org>
> X-IsSubscribed: yes
> Mailing-List: contact gdb-help@sourceware.org; run by ezmlm
> Sender: gdb-owner@sourceware.org
> X-UTwente-MailScanner-Information: Scanned by MailScanner. Contact helpdesk@ITBE.utwente.nl for more information.
> X-UTwente-MailScanner: Found to be clean
> X-MailScanner-From: gdb-return-24948-m.m.kettenis=alumnus.utwente.nl@sourceware.org
> X-XS4ALL-DNSBL-Checked: mxdrop40.xs4all.nl checked 192.87.17.19 against DNS blacklists
> X-Virus-Scanned: by XS4ALL Virus Scanner
> X-XS4ALL-Spam-Score: 0 () 
> X-XS4ALL-Spam: NO
> Envelope-To: mark.kettenis@xs4all.nl
> X-UIDL: 1145270175._smtp.mxdrop40.36794,S=3326
> 
> > Date: Mon, 17 Apr 2006 10:58:43 +0200 (CEST)
> > From: Mark Kettenis <mark.kettenis@xs4all.nl>
> > CC: nickrob@snap.net.nz, gdb@sources.redhat.com
> > 
> > > > Yes, current GDB uses the convention that the frame address is the
> > > > Canonical Frame Address (CFA) as used by the DWARF 2 Call Frame Info
> > > > (CFI).
> > > 
> > > Does this mean that, if the debug info is stabs or something other
> > > than DWARF 2, a different frame address will be displayed for the same
> > > code?
> > 
> > No.  All the different unwinders use the same convention.
> 
> Don't you glean the information from the debug info?  At least for
> functions that violate the normal call frame, you probably must, no?

The only debug format that contains the information is DWARF 2/3.  The
other unwinders all code scanning techniques to find out the CFA.
Those have been adapted to match the CFA as used by GCC.