From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762591Ab2DLTkU (ORCPT ); Thu, 12 Apr 2012 15:40:20 -0400 Received: from smtp.snhosting.dk ([87.238.248.203]:16161 "EHLO smtp.domainteam.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762551Ab2DLTkS (ORCPT ); Thu, 12 Apr 2012 15:40:18 -0400 Date: Thu, 12 Apr 2012 21:40:16 +0200 From: Sam Ravnborg To: Geert Uytterhoeven Cc: Andi Kleen , linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, x86@kernel.org, Andi Kleen Subject: Re: [PATCH 2/2] Add CONFIG_READABLE_ASM Message-ID: <20120412194016.GA30558@merkur.ravnborg.org> References: <1332960678-11879-1-git-send-email-andi@firstfloor.org> <1332960678-11879-2-git-send-email-andi@firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 12, 2012 at 09:08:36PM +0200, Geert Uytterhoeven wrote: > Hi Andi, > > On Wed, Mar 28, 2012 at 20:51, Andi Kleen wrote: > > +ifdef CONFIG_READABLE_ASM > > +# Disable optimizations that make assembler listings hard to read. > > +# reorder blocks reorders the control in the function > > +# ipa clone creates specialized cloned functions > > +# partial inlining inlines only parts of functions > > +KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \ > > +                 $(call cc-option,-fno-ipa-cp-clone,) \ > > +                 $(call cc-option,-fno-partial-inlining) > > +endif Could people move to this century and drop these ugly "\" line-continuations please... People seems to get along in C without but think they should be used in Makefiles.. > This (now in linux-next) causes m68k/allmodconfig to fail for me: > > CHK include/linux/version.h > CHK include/generated/utsrelease.h > CC kernel/bounds.s > cc1: error: unrecognized command line option "-fno-ipa-cp-clone" > > Somehow, "$(call cc-option,-fno-ipa-cp-clone,)" doesn't detect that my > toolchain (gcc version 4.1.2 20061115 (prerelease) (Ubuntu 4.1.1-21)) > doesn't support this option. > > I tried playing with the trailing comma (why do the first 2 tests have it, > and the 3rd one doesn't?), but that didn't make a difference. The trailing comma does not have any affect - it is only ugly and should be dropped. You should try cc-diasable-warning like this: KBUILD_CFLAGS += $(call cc-disable-warning, ipa-cp-clone) from Documentation/kbuild/makefiles.txt: cc-disable-warning cc-disable-warning checks if gcc supports a given warning and returns the commandline switch to disable it. This special function is needed, because gcc 4.4 and later accept any unknown -Wno-* option and only warn about it if there is another warning in the source file. Example: KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable) In the above example, -Wno-unused-but-set-variable will be added to KBUILD_CFLAGS only if gcc really accepts it. The documentation refer to gcc 4.4 - but maybe the older gcc you have has the same behaviour. Sam