From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30946 invoked by alias); 15 May 2012 15:01:57 -0000 Received: (qmail 30937 invoked by uid 22791); 15 May 2012 15:01:56 -0000 X-SWARE-Spam-Status: No, hits=-3.5 required=5.0 tests=AWL,BAYES_00,KHOP_RCVD_UNTRUST,RCVD_IN_HOSTKARMA_NO,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL X-Spam-Check-By: sourceware.org Received: from rock.gnat.com (HELO rock.gnat.com) (205.232.38.15) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 15 May 2012 15:01:43 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by filtered-rock.gnat.com (Postfix) with ESMTP id 5AF0C1C6C70; Tue, 15 May 2012 11:01:42 -0400 (EDT) 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 b5UaFT7ur8WU; Tue, 15 May 2012 11:01:42 -0400 (EDT) Received: from joel.gnat.com (localhost.localdomain [127.0.0.1]) by rock.gnat.com (Postfix) with ESMTP id 2A49E1C67F4; Tue, 15 May 2012 11:01:41 -0400 (EDT) Received: by joel.gnat.com (Postfix, from userid 1000) id 931FA145616; Tue, 15 May 2012 08:01:32 -0700 (PDT) Date: Tue, 15 May 2012 15:01:00 -0000 From: Joel Brobecker To: Yao Qi Cc: gdb-patches@sourceware.org, cltang@codesourcery.com Subject: Re: [PATCH 1/4] New gdb arch hook: return_with_first_hidden_param_p Message-ID: <20120515150132.GR10253@adacore.com> References: <20120503011435.GA3294@adacore.com> <4FA22D7B.1040707@codesourcery.com> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4FB1FCD2.5070302@codesourcery.com> User-Agent: Mutt/1.5.20 (2009-06-14) 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/msg00573.txt.bz2 > > So, you are saying that we have functions who have an extra hidden > > parameter used for something other than the function's return value? > > > > No, the extra hidden parameter's type is the reference of the function's > return type. My point is if we only examine debug info, we don't know > whether hidden parameter is passed, because the debug info is the same > regardless of hidden parameter is passed or not. I may be too naive, or maybe I am not understanding what you are saying, but I find it horrifying that the compiler would generate a parameter DIE for a function if that parameter is not actually passed when calling that function. Did I misunderstand? -- Joel