From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH for-1.7] target-i386: Fix build by providing stub kvm_arch_get_supported_cpuid() Date: Tue, 12 Nov 2013 16:58:01 +0100 Message-ID: <52825009.10506@redhat.com> References: <5281580D.7060305@redhat.com> <52816422.8060002@redhat.com> <52821A62.2050001@redhat.com> <52822958.8060508@redhat.com> <20131112132337.GB2008@redhat.com> <528233DD.6020306@redhat.com> <20131112140935.GD2008@redhat.com> <528241E0.5060503@redhat.com> <52824766.2000507@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Gleb Natapov , Anthony Liguori , QEMU Developers , kvm-devel , Patch Tracking , Andreas Tobler , Anthony Liguori To: Peter Maydell Return-path: Received: from mail-qe0-f54.google.com ([209.85.128.54]:37625 "EHLO mail-qe0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751554Ab3KLP6I (ORCPT ); Tue, 12 Nov 2013 10:58:08 -0500 Received: by mail-qe0-f54.google.com with SMTP id 1so5688150qec.41 for ; Tue, 12 Nov 2013 07:58:07 -0800 (PST) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: Il 12/11/2013 16:32, Peter Maydell ha scritto: > > Is this FUD or do you have examples of bad debuggability of -O1 code? > > The clang manpage says specifically "Note that Clang debug > information works best at -O0. ", and I see no reason to > disbelieve it. In particular, they don't say "we definitely > will never add an optimization to -O1 that makes the debug > info much worse". This doesn't quite answer my question. It looks like another bug that should be reported to clang. "-O1 is somewhere between -O0 and -O2" (quoted from the man page) is a joke, it's not documentation. Every time I look at clang, it seems to me that they are still relying on the "buzz" from their "better syntax errors" blog posts (undeserved these days), and from clang-analyzer (deserved). I don't really see a reason why QEMU should give clang more weight than Windows or Mac OS X. Paolo