From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29325 invoked by alias); 13 Apr 2006 08:12:46 -0000 Received: (qmail 29317 invoked by uid 22791); 13 Apr 2006 08:12:46 -0000 X-Spam-Check-By: sourceware.org Received: from nitzan.inter.net.il (HELO nitzan.inter.net.il) (192.114.186.20) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 13 Apr 2006 08:12:45 +0000 Received: from HOME-C4E4A596F7 (IGLD-83-130-205-75.inter.net.il [83.130.205.75]) by nitzan.inter.net.il (MOS 3.7.3-GA) with ESMTP id DDC09510 (AUTH halo1); Thu, 13 Apr 2006 11:12:29 +0300 (IDT) Date: Thu, 13 Apr 2006 08:12:00 -0000 Message-Id: From: Eli Zaretskii To: Mark Kettenis CC: gdb-patches@sourceware.org In-reply-to: <20060412184717.GA29980@nevyn.them.org> (message from Daniel Jacobowitz on Wed, 12 Apr 2006 14:47:17 -0400) Subject: Re: Save the length of inserted breakpoints Reply-to: Eli Zaretskii References: <20060302221711.GB18830@nevyn.them.org> <200603022301.k22N1qEt008208@elgar.sibelius.xs4all.nl> <20060411214613.GA702@nevyn.them.org> <200604120943.k3C9hYJ8012016@elgar.sibelius.xs4all.nl> <20060412125712.GA22145@nevyn.them.org> <200604121837.k3CIbMwu004466@elgar.sibelius.xs4all.nl> <20060412184717.GA29980@nevyn.them.org> X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2006-04/txt/msg00164.txt.bz2 > Date: Wed, 12 Apr 2006 14:47:17 -0400 > From: Daniel Jacobowitz > Cc: gdb-patches@sourceware.org > > > int target_insert_breakpoint(CORE_ADDR addr, gdb_byte *buf, int *size); > > int target_remove_breakpoint(CORE_ADDR addr, gdb_byte *buf, int size); > > And then if you come up with a reason, you're going to need to hand > edit every one of these targets again. It's not a bundle of fun. Is > that really necessary? > > You need an address because the address at which the breakpoint is > inserted may not match the requested address. This happens in several > different places in the breakpoint infrastructure (I believe I counted > three disjoint hooks for it), but I am particularly looking at > BREAKPOINT_FROM_PC, which takes the PC by reference. In the ARM case, > given 0x4001, it strips the low bit off and returns a two byte > breakpoint. If we don't allow the target to save the > actually-inserted-at address, then it has to call BREAKPOINT_FROM_PC > again. It feels much more robust to me to save this address when we > initially adjust it. Here's where we inserted the breakpoint, so > that's where we should remove it from. > > I can think of plenty of other places where another constant might > be useful. You might want to record which hardware breakpoint > registers were used, for instance, instead of digging around > to figure out which ones to clear. Adding a new member to > "struct bp_target" for that would be easy. FWIW, I agree with Daniel: it is better to pass a struct than its individual members, especially if we expect different targets to use different members of that struct. In other words, passing a struct eases future maintenance pains.