From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28911 invoked by alias); 9 Jan 2013 19:08:42 -0000 Received: (qmail 28903 invoked by uid 22791); 9 Jan 2013 19:08:41 -0000 X-SWARE-Spam-Status: No, hits=-6.5 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_DNSWL_HI,RCVD_IN_HOSTKARMA_W,RP_MATCHES_RCVD,SPF_HELO_PASS X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 09 Jan 2013 19:08:33 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r09J8SfH015594 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 9 Jan 2013 14:08:28 -0500 Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r09J8Q1l015851 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 9 Jan 2013 14:08:27 -0500 From: Tom Tromey To: "Ulrich Weigand" Cc: aburgess@broadcom.com (Andrew Burgess), gdb-patches@sourceware.org, ken@linux.vnet.ibm.com Subject: Re: [PATCH] Vector to scalar casting and widening References: <50E6EB05.8010600@broadcom.com> <201301071623.r07GNBP3015665@d06av02.portsmouth.uk.ibm.com> Date: Wed, 09 Jan 2013 19:08:00 -0000 In-Reply-To: <201301071623.r07GNBP3015665@d06av02.portsmouth.uk.ibm.com> (Ulrich Weigand's message of "Mon, 7 Jan 2013 17:23:11 +0100 (CET)") Message-ID: <87k3rmxjh1.fsf@fleche.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.2.91 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain 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 X-SW-Source: 2013-01/txt/msg00181.txt.bz2 >>>>> "Ulrich" == Ulrich Weigand writes: Ulrich> My understanding of how this is supposed to work out is that GDB Ulrich> "value" operations *do not* actually implement the precise semantics Ulrich> of any of the languages GDB supports; rather, they implement a GDB Ulrich> private semantics of "GDB value" objects. Now, as those are private Ulrich> to GDB, we are free to implement them however we wish; for pragmatic Ulrich> and historical reasons, they do mostly (but not completely!) match Ulrich> C semantics. [...] Ulrich> [ For historical reasons, some of the value_* operations currently Ulrich> change aspects of their behaviour depending on current_language. Ulrich> This is really a bug, and we ought to (and slowly do) move away Ulrich> from this. For example, in a program employing multiple languages Ulrich> simultaneously, GDB value objects might have been created from Ulrich> values in a different language than the "current" one. ] This seems like a good direction to me. Tom