From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id 5ukpE3ObgF/HDQAAWB0awg (envelope-from ) for ; Fri, 09 Oct 2020 13:18:43 -0400 Received: by simark.ca (Postfix, from userid 112) id 426401EF6F; Fri, 9 Oct 2020 13:18:43 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server2.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id B0E4E1E58D for ; Fri, 9 Oct 2020 13:18:41 -0400 (EDT) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D260D3846411; Fri, 9 Oct 2020 17:18:40 +0000 (GMT) Received: from rock.gnat.com (rock.gnat.com [IPv6:2620:20:4000:0:a9e:1ff:fe9b:1d1]) by sourceware.org (Postfix) with ESMTP id 25E433850409 for ; Fri, 9 Oct 2020 17:18:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 25E433850409 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=adacore.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tromey@adacore.com Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id B0FB1560BC; Fri, 9 Oct 2020 13:18:37 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at gnat.com Received: from rock.gnat.com ([127.0.0.1]) by localhost (rock.gnat.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id v7IaOa3VljSG; Fri, 9 Oct 2020 13:18:37 -0400 (EDT) Received: from murgatroyd (174-16-122-38.hlrn.qwest.net [174.16.122.38]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by rock.gnat.com (Postfix) with ESMTPSA id 54983116462; Fri, 9 Oct 2020 13:18:37 -0400 (EDT) From: Tom Tromey To: Andrew Burgess Subject: Re: [PATCH] Fix bit offset regression References: <20201009134130.3785956-1-tromey@adacore.com> <20201009142707.GR605036@embecosm.com> X-Attribution: Tom Date: Fri, 09 Oct 2020 11:18:36 -0600 In-Reply-To: <20201009142707.GR605036@embecosm.com> (Andrew Burgess's message of "Fri, 9 Oct 2020 15:27:07 +0100") Message-ID: <87v9fjb9n7.fsf@tromey.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gdb-patches@sourceware.org, Tom Tromey Errors-To: gdb-patches-bounces@sourceware.org Sender: "Gdb-patches" >> SET_FIELD_BITPOS (*fp, (FIELD_BITPOS (*fp) >> - + attr->as_unsigned ())); >> + + attr->constant_value (0))); Andrew> I wondered what the `0` was all about here, so I took a look... [...] Andrew> I'm not sure I'm any more enlightened about the default value... It's a bit of an API error, IMO. Basically, constant_value lets you specify a default, so that if the attribute does not have constant form, then the default is returned. However, in this patch (and perhaps in other cases, I didn't look), the attribute is already known to have constant form, so there's no need for a default. Perhaps I should add a default-less overload that asserts. What do you think? Andrew> None of which has anything to do with your patch, which looks Andrew> fine. I'm going to check it in. Tom