From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 30193 invoked by alias); 23 Aug 2002 17:29:22 -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 30186 invoked from network); 23 Aug 2002 17:29:20 -0000 Received: from unknown (HELO mail-out1.apple.com) (17.254.0.52) by sources.redhat.com with SMTP; 23 Aug 2002 17:29:20 -0000 Received: from mailgate2.apple.com (A17-129-100-225.apple.com [17.129.100.225]) by mail-out1.apple.com (8.11.3/8.11.3) with ESMTP id g7NHTHL12293 for ; Fri, 23 Aug 2002 10:29:17 -0700 (PDT) Received: from scv3.apple.com (scv3.apple.com) by mailgate2.apple.com (Content Technologies SMTPRS 4.2.1) with ESMTP id for ; Fri, 23 Aug 2002 10:29:16 -0700 Received: from inghji.apple.com (inghji.apple.com [17.201.22.240]) by scv3.apple.com (8.11.3/8.11.3) with ESMTP id g7NHTG305228 for ; Fri, 23 Aug 2002 10:29:16 -0700 (PDT) Date: Fri, 23 Aug 2002 10:50:00 -0000 Subject: Re: [RFC] breakpoints and function prologues... Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v543) From: Jim Ingham To: gdb-patches@sources.redhat.com Content-Transfer-Encoding: 7bit In-Reply-To: <1030059293.13128.ezmlm@sources.redhat.com> Message-Id: X-SW-Source: 2002-08/txt/msg00756.txt.bz2 On Thursday, August 22, 2002, at 04:34 PM, gdb-patches-digest-help@sources.redhat.com wrote: >> The question is, is there a strong reason to change a behavior >> that has been consistent for a very long time (even if undocumented). >> Even if the ability to debug the prologue is un-important for most >> users, it is important to some, and those users (GCC developers, >> for instance) may be quite accustomed to the current behavior. >> I am, for instance... The varobj code will fail with file:line number breakpoint setting on the { that starts the function. This is, of course, not a problem for command-line gdb users, but varobj IS a part of gdb... Until we have the CFI stuff well enough set up that, on landing at the beginning of the prologue, the scanner will tell us where the stack frame WILL be when it has been set up so we can record this properly, this will be a problem. > Incidentally, it would make the new behavior more in line with the > behavior seen when breaking by function name. If later we decide to > change the "break funcname" to stop skipping prologues because GDB now > has all the machinery that makes the skipping unnecessary, I would > likewise argue that we should change back the behavior of "break > linenum" as well. > > The patch I sent you makes prologue skipping for file:line breakpoints hang off the same flag - "funfirstline" - that the function name ones use. So if we decide to back it out, we just change the value we pass to decode_line_1, and you are done... Jim -- Jim Ingham jingham@apple.com Developer Tools - gdb Apple Computer