From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24391 invoked by alias); 23 Aug 2004 21:12:23 -0000 Mailing-List: contact gdb-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sources.redhat.com Received: (qmail 24381 invoked from network); 23 Aug 2004 21:12:22 -0000 Received: from unknown (HELO lakermmtao11.cox.net) (68.230.240.28) by sourceware.org with SMTP; 23 Aug 2004 21:12:22 -0000 Received: from white ([68.9.64.121]) by lakermmtao11.cox.net (InterMail vM.6.01.03.02.01 201-2131-111-104-103-20040709) with ESMTP id <20040823211221.GWZH6461.lakermmtao11.cox.net@white> for ; Mon, 23 Aug 2004 17:12:21 -0400 Received: from bob by white with local (Exim 3.35 #1 (Debian)) id 1BzM71-00045w-00 for ; Mon, 23 Aug 2004 17:12:19 -0400 Date: Mon, 23 Aug 2004 21:12:00 -0000 From: Bob Rossi To: gdb@sources.redhat.com Subject: Re: GDB/MI Output Syntax ambiguity Message-ID: <20040823211219.GB15374@white> Mail-Followup-To: gdb@sources.redhat.com References: <20040823210314.GA15374@white> <20040823210924.GA22417@nevyn.them.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040823210924.GA22417@nevyn.them.org> User-Agent: Mutt/1.3.28i X-SW-Source: 2004-08/txt/msg00299.txt.bz2 On Mon, Aug 23, 2004 at 05:09:24PM -0400, Daniel Jacobowitz wrote: > On Mon, Aug 23, 2004 at 05:03:14PM -0400, Bob Rossi wrote: > > Hi, > > > > I am generating a bottom up parser for 'GDB/MI Output Syntax' using > > bison. Unfortunately, I think that I found an ambiguity, which makes it > > not easily parsable. Please correct me if I am wrong. > > > > output -> ( out-of-band-record )* [ result-record ] "(gdb)" nl > > result-record -> [ token ] "^" result-class ( "," result )* nl > > out-of-band-record -> async-record | stream-record > > async-record -> exec-async-output | status-async-output | notify-asyn > > exec-async-output -> [ token ] "*" async-output > > status-async-output -> [ token ] "+" async-output > > notify-async-output -> [ token ] "=" async-output > > > > I am assuming that the grammar above for 'output' means that there can > > be 0 or more 'out-of-band-record', followed by 0 or 1 'result-record', > > followed by '(gdb)' and then a newline. > > This is easily solved. For instance, factor the optional token out of > async-record and result-record, and handle output as: > output -> [token] ( out-of-band-record-1 [token] )* [ result-record ] "(gdb)" nl > > > I'm not sure how faithful to the documented grammar GDB is... but > that's a separate problem. Thanks! Hopefully it won't be to long before I'm done :) Bob Rossi