From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5778 invoked by alias); 18 Mar 2010 18:14:28 -0000 Received: (qmail 5769 invoked by uid 22791); 18 Mar 2010 18:14:26 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from mail.codesourcery.com (HELO mail.codesourcery.com) (38.113.113.100) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 18 Mar 2010 18:14:20 +0000 Received: (qmail 3103 invoked from network); 18 Mar 2010 18:14:18 -0000 Received: from unknown (HELO orlando.localnet) (pedro@127.0.0.2) by mail.codesourcery.com with ESMTPA; 18 Mar 2010 18:14:18 -0000 From: Pedro Alves To: tromey@redhat.com Subject: Re: RFC: finish_command_continuation and errors Date: Thu, 18 Mar 2010 18:14:00 -0000 User-Agent: KMail/1.12.2 (Linux/2.6.31-19-generic; KDE/4.3.2; x86_64; ; ) Cc: gdb-patches@sourceware.org References: <201003181728.30450.pedro@codesourcery.com> In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201003181814.16773.pedro@codesourcery.com> X-IsSubscribed: yes 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: 2010-03/txt/msg00676.txt.bz2 On Thursday 18 March 2010 17:59:02, Tom Tromey wrote: > Pedro> For the record, can you show us which error was that? > > In this case it was: > > Value returned is $9 = warning: RTTI symbol not found for class 'java::lang::String' > Cannot access memory at address 0x0 Thanks. Looks strange that GDB found something missing, and still tried to use address 0x0 though. Is the 0 GDB working with a NULL type somewhere? Or is that unrelated? > Pedro> This probably also fixes frontends: the normal_stop observers > Pedro> notification call just a bit below was skipped too, which means > Pedro> the MI *stopped notification must have gone missing; a frontend > Pedro> was being left with no idea the thread had stopped. Could you > Pedro> check with your test, but running with -i=mi, that > Pedro> mi_on_normal_stop also isn't throwing an exception too in your > Pedro> case? I suspect not, but just in case. You can issue the normal > Pedro> CLI commands while in -i=mi to test this. > > I tried this and it worked fine after my patch. From what I can see, > mi_on_normal_stop doesn't try to print the return value. Yes. Thanks. I didn't know what exactly was failing before -- I was wondering if frame printing would also be failing. > It seems to me that, abstractly, observers should not be allowed to > throw exceptions. Perhaps the observer machinery itself ought to catch > them. My reasoning is that letting an observer throw an exception will > make the observer mechanism apparently unreliable: a given observer > might or might not be called, depending on whether some earlier observer > encountered an error. Yes, agreed in general. I think some classes of errors still need escaping though, like internal errors, and Quits. -- Pedro Alves