From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16950 invoked by alias); 16 May 2012 20:56:09 -0000 Received: (qmail 16942 invoked by uid 22791); 16 May 2012 20:56:09 -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 20:55:55 +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 q4GKtpSI012062 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 16 May 2012 16:55:51 -0400 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 q4GKtnvt015826 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 16 May 2012 16:55:50 -0400 From: Tom Tromey To: Yao Qi Cc: , Subject: Re: [PATCH 1/4] New gdb arch hook: return_with_first_hidden_param_p References: <1334755073-26528-1-git-send-email-yao@codesourcery.com> Date: Wed, 16 May 2012 20:56:00 -0000 In-Reply-To: <1334755073-26528-1-git-send-email-yao@codesourcery.com> (Yao Qi's message of "Wed, 18 Apr 2012 21:17:50 +0800") Message-ID: <87zk97n8ve.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/msg00630.txt.bz2 >>>>> "Yao" == Yao Qi writes: Yao> Hi, this patch series is about fixing return values in C++ in GDB inf-call. Thanks. I read through the whole thread and dug into the code a bit as well. I think your approach is fine. Yao> Unfortunately, GCC is not correct here. currently GCC processes Yao> the return value RTL expanding like this, in Yao> gcc/function.c:assign_parms_augmented_arg_list(): I suppose it would be nice to get some commitment on the GCC side to declare this a non-bug, and part of the ABI. Yao> +int Yao> +default_return_with_first_hidden_param_p (struct gdbarch *gdbarch, Yao> + struct type *type) This could use an introductory comment, just explaining it is an implementation suitable for use by such-and-such gdbarch method. Yao> +# Return true if the return value of function is stored in the first hidden parameter. Yao> +# In theory, this feature should be language-dependent, specified by language and its ABI, Yao> +# such as C++. Unfortunately, compiler may implement it to a target-dependent feature. Yao> +# So that we need such hook here to be aware of this in GDB. Over-long lines. Ok with those fixes. Tom