From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 70267 invoked by alias); 22 Feb 2019 17:12:30 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 69884 invoked by uid 89); 22 Feb 2019 17:12:29 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_PASS autolearn=ham version=3.3.2 spammy=H*f:sk:4e1e43f, gtype.state, gt-*.h, gt*h X-HELO: mx1.suse.de Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 22 Feb 2019 17:12:28 +0000 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 32EFFAD6B; Fri, 22 Feb 2019 17:12:26 +0000 (UTC) Date: Fri, 22 Feb 2019 17:12:00 -0000 User-Agent: K-9 Mail for Android In-Reply-To: <20190222160346.GE7611@tucnak> References: <4e1e43f2-f944-7067-d4ba-71b42ae3f2c8@redhat.com> <20190222160346.GE7611@tucnak> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [RFC] Change PCH "checksum" To: Jakub Jelinek ,Jeff Law CC: gcc@gcc.gnu.org From: Richard Biener Message-ID: <00AD17E2-AB98-4C6B-A6D2-EF8B1A867DB9@suse.de> X-SW-Source: 2019-02/txt/msg00125.txt.bz2 On February 22, 2019 5:03:46 PM GMT+01:00, Jakub Jelinek = wrote: >On Fri, Feb 22, 2019 at 08:47:09AM -0700, Jeff Law wrote: >> > 2019-02-22 Richard Biener >> >=20 >> > c/ >> > * Make-lang.in (cc1-checksum.c): Checksum only gtype-desc.o. >> >=20 >> > cp/ >> > * Make-lang.in (cc1plus-checksum.c): Checksum only gtype-desc.o. >> >=20 >> > objc/ >> > * Make-lang.in (cc1obj-checksum.c): Checksum only gtype-desc.o. >> >=20 >> > objcp/ >> > * Make-lang.in (cc1objplus-checksum.c): Checksum only >gtype-desc.o. >> ISTM that gtype-desc effectively describes the structure of all the >GC data. >>=20 >> Given we're summing the thin-archives, we're already missing things >like >> a change in static data. So I don't think your patch is a >degradation >> over the current state. I'm not 100% sure the current state is >correct >> though :-) > >Does it cover everything though? I believe gtype-desc.c only covers a >small >portion, the rest is in all the gtype-*.h and gt-*.h headers that are >included in the various object files. >So, either we need to checksum all the object files that include gt-*.h >or >gtype-*.h headers in addition to gtype-desc.o, or perhaps checksum >gtype.state ? Though, that state wouldn't cover changes in ABI etc. Gtype-desc.o does not cover everything indeed. But the current state doesn'= t cover Gtype-desc.o... Slightly better would be to Re-include frontend obj= ects.=20 Not sure why we checksummed build flags for example. Isn't it enough to han= dle gty walking changes? Anyway, for suse I'm probably using the build-id thing.=20 Richard.=20 > Jakub