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Date: Fri, 31 Aug 2012 09:59:00 -0000
From: Eli Zaretskii <eliz@gnu.org>
Subject: Re: PATCH: error reading variable: value has been optimized out
In-reply-to: <871uisibi3.fsf@fleche.redhat.com>
To: Tom Tromey <tromey@redhat.com>
Cc: jan.kratochvil@redhat.com, aburgess@broadcom.com, gdb-patches@sourceware.org
Reply-to: Eli Zaretskii <eliz@gnu.org>
Message-id: <83fw73qt4m.fsf@gnu.org>
References: <50376F3B.1080407@broadcom.com> <20120826171840.GA21205@host2.jankratochvil.net> <871uisibi3.fsf@fleche.redhat.com>
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> From: Tom Tromey <tromey@redhat.com>
> Cc: Andrew Burgess <aburgess@broadcom.com>,        "gdb-patches\@sourceware.org" <gdb-patches@sourceware.org>
> Date: Mon, 27 Aug 2012 09:46:12 -0600
> 
> Offhand it seems as though read_frame_register_value could create an
> lval_computed value if any register it needs is optimized out.  I don't
> know whether this is worth the effort.

IMO, any enhancements that allow better support for optimized-out
variables are important.  Having GDB refuse to show a value of a
variable, letting you go hunt for it via disassembly and register
sniffing, is among the worst user-experiences I have debugging
optimized programs.