From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21556 invoked by alias); 18 Sep 2013 19:35:24 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 21543 invoked by uid 89); 18 Sep 2013 19:35:24 -0000 Received: from mtaout20.012.net.il (HELO mtaout20.012.net.il) (80.179.55.166) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 18 Sep 2013 19:35:24 +0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.8 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,KHOP_THREADED autolearn=ham version=3.3.2 X-HELO: mtaout20.012.net.il Received: from conversion-daemon.a-mtaout20.012.net.il by a-mtaout20.012.net.il (HyperSendmail v2007.08) id <0MTC00F00663YR00@a-mtaout20.012.net.il> for gdb-patches@sourceware.org; Wed, 18 Sep 2013 22:34:59 +0300 (IDT) Received: from HOME-C4E4A596F7 ([87.69.4.28]) by a-mtaout20.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0MTC00F6W6EAN780@a-mtaout20.012.net.il>; Wed, 18 Sep 2013 22:34:59 +0300 (IDT) Date: Wed, 18 Sep 2013 19:35:00 -0000 From: Eli Zaretskii Subject: Re: [PATCH+DOC] Print registers not saved in the frame as "", instead of "". In-reply-to: <5239E44B.7030704@redhat.com> To: Pedro Alves Cc: aburgess@broadcom.com, gdb-patches@sourceware.org, mark.kettenis@xs4all.nl Reply-to: Eli Zaretskii Message-id: <83six1nct8.fsf@gnu.org> References: <5200F55E.2050308@broadcom.com> <201308061318.r76DIMdd016369@glazunov.sibelius.xs4all.nl> <5200FECF.7030304@broadcom.com> <201308061541.r76FfYQN022875@glazunov.sibelius.xs4all.nl> <520142D9.4030304@redhat.com> <5208E3C8.7060107@broadcom.com> <5208E938.3080305@redhat.com> <201308122001.r7CK1862007934@glazunov.sibelius.xs4all.nl> <520E7255.7080206@redhat.com> <5211F25A.5070907@broadcom.com> <5228B15F.7060108@redhat.com> <5228B2D8.7060604@broadcom.com> <5237567C.8050406@redhat.com> <5239B2D8.4030403@broadcom.com> <5239CCB3.605@redhat.com> <83zjram6sw.fsf@gnu.org> <5239E44B.7030704@redhat.com> X-IsSubscribed: yes X-SW-Source: 2013-09/txt/msg00621.txt.bz2 > Date: Wed, 18 Sep 2013 18:35:07 +0100 > From: Pedro Alves > CC: aburgess@broadcom.com, gdb-patches@sourceware.org, mark.kettenis@xs4all.nl > > > I don't understand the significance of the last paragraph. > > It's preexisting actually. I just added the "debug or unwind info" bit. > But yeah, it's confusing. I _think_ I know what it's talking about. > I think "makes no difference" refers to GDB assuming $reg in an outer > frame is found at the same location as in the inner frame (that is, > assuming the call clobbered register hasn't been clobbered yet). > > I've rewritten all this text now. What do you think? We are almost there, just a few minor comments below. > > Also, shouldn't we mention optimizations as (the main) reason for > > registers being unavailable? > > I'm not actually sure how to say that. Not sure you actually > always need optimization to see this in the debugger. But maybe > we don't need to in this new version. :-) One of the comments below addresses that. > +In some ABIs, some registers may not be preserved, or saved, across > +function calls. It's enough to mention optimizations here, as in In some ABIs, or in optimized code, some registers may not be preserved > +the outer frame, you may also be affecting the inner frame. Values of > +registers that @value{GDBN} can definitely tell from the debug/unwind > +info were not saved in their stack frames and there's nowhere to > +retrieve the original value from anymore are shown as > +@w{@samp{}}. The last sentence is unduly hard to read, because it uses passive tense too aggressively. I would rephrase: If @value{GDBN} can definitely tell from the debug/unwind info that the value of a register was not saved in its stack frame, and there's no other place for it from which to retrieve that register's original value, @value{GDBN} will show the value of such a register as @w{@samp{}}. OK with those changes. Thanks.