From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28351 invoked by alias); 6 Aug 2002 03:01:45 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 28343 invoked from network); 6 Aug 2002 03:01:41 -0000 Received: from unknown (HELO localhost.redhat.com) (24.112.240.27) by sources.redhat.com with SMTP; 6 Aug 2002 03:01:41 -0000 Received: from ges.redhat.com (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 419133D82; Mon, 5 Aug 2002 23:01:37 -0400 (EDT) Message-ID: <3D4F3C11.3000506@ges.redhat.com> Date: Mon, 05 Aug 2002 20:01:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.0) Gecko/20020802 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Joel Brobecker Cc: gdb-patches@sources.redhat.com Subject: Re: [RFA] enable software single step on alpha-osf References: <20020718203205.GB26990@gnat.com> <3D4DBBC8.5000906@ges.redhat.com> <20020805184920.GC892@gnat.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2002-08/txt/msg00112.txt.bz2 >> Can you confirm that the code is encountering a situtation where both >> breakpoints_inserted and singlestep_breakpoints_inserted_p are true. I >> think this occures when doing a single step after stepping off of a >> breakpoint. When single stepping off a breakpoint, only >> singlestep_breakpoints_inserted_p would be true. >> >> If this is the case then the comments should make mention of it. It >> also makes the re-ordered if statement part of the patch correct. > > > Yes, I can confirm this, and this should happen fairly often: suppose > you have inserted a regular breakpoint in your program, anywhere, and > then do a single step. Before resuming the inferior, GDB will re-insert > the breakpoints, and set breakpoints_inserted. At the same time, because > we are doing a s/w single step, singlestep_breakpoints_inserted_p will > be set too. Did I miss something? Thanks. No you didn't miss anything, I just want to be sure WFI is nasty. The problem won't have been noticed previously as only the older targets use software single-step and I don't know how often their testsuite is beaten on. > As for the re-ordering, I made it because I saw some regressions in the > testsuite after switching to s/w single step. Unfortunately, I don't > remember which ones, I would have to rerun the testsuite without this > change to find them again. But the following comment explains in which > cases the re-ordering was necessary: Yes, ok, the part of the patch that re-orders the test is ok. ---- > I've tried as much as I can to make sure this can not happen, but I am > not familiar enough to have a good level of confidence in my analysis. > All I can say is: this patch fixes all the regressions observed in the > testsuite after switching to software single step. I know this is no > absolute proof, but that gives me a certain level of confidence. BTW, if someone ever claims to have a ``good level of confidence'' in that code, assume that they are lieing :-^ I'm still thinking about this bit, trying to find a way of not so much increasing our confidence but at least putting us in a position where we are more sure about what to do when we next encounter a problem. Andrew