From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 31170 invoked by alias); 10 Jun 2004 16:58:24 -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 31162 invoked from network); 10 Jun 2004 16:58:23 -0000 Received: from unknown (HELO cuddles.cambridge.redhat.com) (81.96.64.123) by sourceware.org with SMTP; 10 Jun 2004 16:58:23 -0000 Received: from redhat.com (localhost.localdomain [127.0.0.1]) by cuddles.cambridge.redhat.com (8.12.8/8.12.8) with ESMTP id i5AGtqVL022978; Thu, 10 Jun 2004 17:56:02 +0100 Received: (from aph@localhost) by redhat.com (8.12.8/8.12.8/Submit) id i5AGtpDG022974; Thu, 10 Jun 2004 17:55:51 +0100 From: Andrew Haley MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16584.37526.974458.647364@cuddles.cambridge.redhat.com> Date: Thu, 10 Jun 2004 16:58:00 -0000 To: Ian Lance Taylor Cc: tromey@redhat.com, Daniel Jacobowitz , java@gcc.gnu.org, gdb@sources.redhat.com Subject: Re: Binary Compatibility: debug info for compiled Java programs In-Reply-To: References: <16582.65277.81118.189889@cuddles.cambridge.redhat.com> <20040609130859.GA7514@nevyn.them.org> <16583.3516.604885.805420@cuddles.cambridge.redhat.com> <20040609132951.GA8017@nevyn.them.org> <16583.4773.74100.735457@cuddles.cambridge.redhat.com> <20040609221710.GA16922@nevyn.them.org> <87ise0bc8y.fsf@fleche.redhat.com> <20040610163718.GA24803@nevyn.them.org> <874qpjbcju.fsf@fleche.redhat.com> X-SW-Source: 2004-06/txt/msg00099.txt.bz2 Ian Lance Taylor writes: > Tom Tromey writes: > > > The symbols in the otable (and actually I've been using shorthand > > here, we have a second "atable" for addresses as well -- same > > difference though) are resolved when the class ("Foo") is linked. In > > Java this is done at runtime, the JVM Spec (and perhaps the JLS) has > > information on the precise steps involved in class preparation and > > initialization. > > By the way, Tom and Andrew, I meant to ask, but I forgot: would it > make sense to build the numeric otables and atables for the common > case, and then recompute only when required? That's possibly true, but you'd somehow have to discover that something had changed, and I'm not sure how you'd do that without doing the lookups. > I have to think that the common case is pretty darn common--I'm > sure people don't spend all their time loading classes into > different hierarchies. What is very common is for people to distribute Java binaries without specifying the exact versions of the classes they depend on. So, it's normal for the run-time library environment of a Java program to be different from the compile-time environment. The whole idea of binary compatibility is to make this possible. Andrew.