From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 2970 invoked by alias); 13 Apr 2002 19:59:10 -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 2927 invoked from network); 13 Apr 2002 19:59:08 -0000 Received: from unknown (HELO nevyn.them.org) (128.2.145.6) by sources.redhat.com with SMTP; 13 Apr 2002 19:59:08 -0000 Received: from drow by nevyn.them.org with local (Exim 3.35 #1 (Debian)) id 16wTg9-0004lE-00 for ; Sat, 13 Apr 2002 15:59:21 -0400 Date: Sat, 13 Apr 2002 12:59:00 -0000 From: Daniel Jacobowitz To: gdb@sources.redhat.com Subject: Re: Lifetime of local variables Message-ID: <20020413155921.A18279@nevyn.them.org> Mail-Followup-To: gdb@sources.redhat.com References: <86u1qghdp5.fsf@einstein.home-of-linux.org> <20020412194304.B11562@nevyn.them.org> <86bscnesxy.fsf@einstein.home-of-linux.org> <20020413143246.B13608@nevyn.them.org> <86vgav77oa.fsf@einstein.home-of-linux.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86vgav77oa.fsf@einstein.home-of-linux.org> User-Agent: Mutt/1.3.23i X-SW-Source: 2002-04/txt/msg00236.txt.bz2 On Sat, Apr 13, 2002 at 08:52:21PM +0200, Martin Baulig wrote: > Daniel Jacobowitz writes: > > > On Sat, Apr 13, 2002 at 01:31:05PM +0200, Martin Baulig wrote: > > > Daniel Jacobowitz writes: > > > > Also, I believe that this should be entirely subsumed by .debug_loc. > > > > The first variable's value may no longer be available, but it has not > > > > actually gone out of scope, has it? We should list it but claim that > > > > its value is unavailable. > > > > > > It has actually gone out of scope. I want to use this to debug machine > > > generated IL code and the JIT may want to create local variables > > > on-the-fly. For variables which have actually been defined by a human > > > programmer, listing them and claiming that their value is no longer > > > available is IMHO the right thing to do - but I'd like to tell the > > > debugger to make a machine-generated variable disappear when it's no > > > longer used, otherwise you'd get a large number of automatic variables > > > (having numbers, not names, which makes it even more confusing to the > > > user) and only a very few of them are actually used. > > > > What business does the JIT have actually creating local variables > > (rather than temporaries, which don't get names)? I don't understand. > > What's the difference between a local variable and a temporary variable ? There's no reason for temporaries to have names, or to appear in debug info at all. I don't see why you need them. > > > Btw. are there any plans to implement .debug_loc anytime soon, I need > > > this for something else ? > > > > I believe it's in progress. > > Well, this is probably the correct place to put this (and then use > DW_AT_artificial or something like this to make the variables > disappear outside their lifetime). Sounds good to me. -- Daniel Jacobowitz Carnegie Mellon University MontaVista Software Debian GNU/Linux Developer