From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21091 invoked by alias); 16 May 2012 21:03:59 -0000 Received: (qmail 21083 invoked by uid 22791); 16 May 2012 21:03:58 -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,SPF_HELO_PASS,T_RP_MATCHES_RCVD 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, 16 May 2012 21:03:41 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q4GL3GML014724 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 16 May 2012 17:03:16 -0400 Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q4GL3EEk003977 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 16 May 2012 17:03:14 -0400 From: Tom Tromey To: Joel Brobecker Cc: Yao Qi , gdb-patches@sourceware.org, cltang@codesourcery.com Subject: Re: [PATCH 1/4] New gdb arch hook: return_with_first_hidden_param_p References: <20120504175830.GQ15555@adacore.com> <4FA743EC.1080903@codesourcery.com> <20120507201345.GX15555@adacore.com> <4FAA2D25.4060700@codesourcery.com> <20120510212054.GA5886@adacore.com> <4FACEB4B.1060603@codesourcery.com> <20120514171453.GL10253@adacore.com> <4FB1FCD2.5070302@codesourcery.com> <20120515150132.GR10253@adacore.com> <4FB304B3.4080806@codesourcery.com> <20120516153113.GX10253@adacore.com> Date: Wed, 16 May 2012 21:03:00 -0000 In-Reply-To: <20120516153113.GX10253@adacore.com> (Joel Brobecker's message of "Wed, 16 May 2012 08:31:13 -0700") Message-ID: <87ipfvn8j1.fsf@fleche.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.0.95 (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: 2012-05/txt/msg00635.txt.bz2 >>>>> "Joel" == Joel Brobecker writes: Joel> Now, because I don't know the C++ ABI at all, I don't know whether Joel> it is expected that some architectures would have a hidden parameter Joel> for the return value, while some don't. Is that allowed? Regardless, Joel> it sounds like a gdbarch method would the logical approach... If Joel> that is the case, I'd rather someone with more knowledge with C++ Joel> did the actual review, because I wouldn't be able to say whether Joel> the implementation makes sense or not. Basically what happened is that the ABI was intended to work one way for C++, but then due to an oversight, some GCC targets applied the same rule to all languages. So, different arches have different ABIs in practice. This series, IIUC, just changes gdb to recognize the existing reality. Tom