From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24720 invoked by alias); 24 Sep 2003 18:12:55 -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 1531 invoked from network); 24 Sep 2003 17:37:00 -0000 Received: from unknown (HELO legolas.inter.net.il) (192.114.186.24) by sources.redhat.com with SMTP; 24 Sep 2003 17:37:00 -0000 Received: from zaretski (pns03-208-8.inter.net.il [80.230.208.8]) by legolas.inter.net.il (Mirapoint Messaging Server MOS 3.3.7-GR) with ESMTP id AJP03032; Wed, 24 Sep 2003 20:21:42 +0300 (IDT) Date: Wed, 24 Sep 2003 18:12:00 -0000 From: "Eli Zaretskii" To: Saravanan Message-Id: <6654-Wed24Sep2003201904+0300-eliz@elta.co.il> CC: gdb@sources.redhat.com In-reply-to: <3F717475.33E13BC4@india.hp.com> (message from Saravanan on Wed, 24 Sep 2003 16:09:49 +0530) Subject: Re: Tracepoint support in Cygnus GDB ? Reply-to: Eli Zaretskii References: <3F717475.33E13BC4@india.hp.com> X-SW-Source: 2003-09/txt/msg00299.txt.bz2 > Date: Wed, 24 Sep 2003 16:09:49 +0530 > From: Saravanan > > 1. Why does GDB not provide this support for local > host ? Simple: because no one wrote tracepoints support for native debugging. > 2. Is it not the case that the features (supposed to > be) provided by tracepoints can be done using > breakpoint features only (for instance , we can > specify COMMANDS for a breakpoint just as we can > specify ACTIONS for tracepoints) ? Yes. But tracepoints are supposed to be much more lightweight (because only raw data is accumulated during the program's run, while complicated and expensive computations like evaluation of arbitrary expressions, are left for later). So, theoretically, if tracepoints were available for native debugging, one could perhaps debug programs without disrupting their time scale too much, maybe even debug real-time programs (well, one's allowed to dream once in a while, right? ;-). > 3. Does tracepoint use the same TRAP (or ILLEGAL ) > instruction mechanism for tracepoints as it does for > breakpoints? IIRC, yes.