From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12757 invoked by alias); 3 Jun 2014 15:41:00 -0000 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 Received: (qmail 12704 invoked by uid 89); 3 Jun 2014 15:40:59 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 03 Jun 2014 15:40:58 +0000 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s53FeuDY007591 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 3 Jun 2014 11:40:56 -0400 Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s53Fese0030074; Tue, 3 Jun 2014 11:40:55 -0400 Message-ID: <538DEC86.3050007@redhat.com> Date: Tue, 03 Jun 2014 15:41:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Joel Brobecker CC: gdb-patches@sourceware.org Subject: Re: [RFA/7.8] user breakpoint not inserted if software-single-step at same location References: <1401394280-14999-1-git-send-email-brobecker@adacore.com> <5387BFF0.6010208@redhat.com> <20140530122253.GC4289@adacore.com> <53887ED5.5050603@redhat.com> <20140530132659.GD4289@adacore.com> <20140530193549.GF4289@adacore.com> <538D05CC.8050608@redhat.com> <538D85A9.5010004@redhat.com> <538DC98E.9050004@redhat.com> <20140603133539.GM4289@adacore.com> In-Reply-To: <20140603133539.GM4289@adacore.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-SW-Source: 2014-06/txt/msg00090.txt.bz2 On 06/03/2014 02:35 PM, Joel Brobecker wrote: > Hi Pedro, > >>> Bah, I woke up realizing that the version I posted forgets to >>> clone the shadow buffer! Let me fix that and repost... > > You are producing patches so fast, I am wondering if I will be able > to keep up! :-) :-) >> @@ -15138,12 +15196,30 @@ deprecated_insert_raw_breakpoint (struct gdbarch *gdbarch, >> struct address_space *aspace, CORE_ADDR pc) >> { >> struct bp_target_info *bp_tgt; >> + struct bp_location *bl; >> >> bp_tgt = XCNEW (struct bp_target_info); >> >> bp_tgt->placed_address_space = aspace; >> bp_tgt->placed_address = pc; >> >> + /* If an unconditional non-raw breakpoint is already inserted at >> + that location, there's no need to insert another. However, with >> + target-side evaluation of breakpoint conditions, if the >> + breakpoint that is currently inserted on the target is >> + conditional, we need to make it unconditional. Note that a >> + breakpoint with target-side commands is not reported even if >> + unconditional, so we need to remove the commands from the target >> + as well. */ >> + bl = find_non_raw_software_breakpoint_inserted_here (aspace, pc); >> + if (bl != NULL >> + && VEC_empty (agent_expr_p, bl->target_info.conditions) >> + && VEC_empty (agent_expr_p, bl->target_info.tcommands)) >> + { >> + bp_target_info_copy_insertion_state (bp_tgt, &bl->target_info); >> + return bp_tgt; >> + } >> + > > ISTM that you are assuming that there would only be one other breakpoint > inserted at this location. What if there were more? Yep, it's a valid assumption. Only one of those can be the one that is actually inserted in the target. All others breakpoints are considered duplicates, with bl->duplicate == 1 and bl->inserted == 0, and never reach the target. The duplicate location logic in the tail of update_global_location_list takes care of it: /* This and the above ensure the invariant that the first location is not duplicated, and is the inserted one. All following are marked as duplicated, and are not inserted. */ if (loc->inserted) swap_insertion (loc, *loc_first_p); loc->duplicate = 1; The one that is inserted will hold a merge of all the agent expressions (in target_info.conditions and target_info.tcommands) of the target-side conditions and commands of all breakpoints at that address. Those are computed just before that single breakpoint is inserted (build_target_condition_list, build_target_command_list). -- Pedro Alves