Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757292AbcCRKUj (ORCPT ); Fri, 18 Mar 2016 06:20:39 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.47.9]:58427 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751423AbcCRKU3 (ORCPT ); Fri, 18 Mar 2016 06:20:29 -0400 Subject: Re: [PATCH] ARC: build: Turn off -Wmaybe-uninitialized for ARC gcc 4.8 To: Arnd Bergmann References: <1458290783-31491-1-git-send-email-vgupta@synopsys.com> <23667289.mNa1Q2STbY@wuerfel> CC: , Claudiu Zissulescu , Michal Marek , "Geert Uytterhoeven" , , Newsgroups: gmane.linux.kbuild.devel,gmane.linux.kernel.arc,gmane.linux.kernel From: Vineet Gupta Message-ID: <56EBD65B.10109@synopsys.com> Date: Fri, 18 Mar 2016 15:50:11 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <23667289.mNa1Q2STbY@wuerfel> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.12.197.157] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1970 Lines: 49 On Friday 18 March 2016 03:22 PM, Arnd Bergmann wrote: > On Friday 18 March 2016 14:16:23 Vineet Gupta wrote: >> diff --git a/arch/arc/Makefile b/arch/arc/Makefile >> index fed12f39d8ce..aeb101e8e674 100644 >> --- a/arch/arc/Makefile >> +++ b/arch/arc/Makefile >> @@ -48,9 +48,14 @@ endif >> upto_gcc44 := $(call cc-ifversion, -le, 0404, y) >> atleast_gcc44 := $(call cc-ifversion, -ge, 0404, y) >> atleast_gcc48 := $(call cc-ifversion, -ge, 0408, y) >> +is_gcc48 := $(call cc-ifversion, -eq, 0408, y) >> >> cflags-$(atleast_gcc44) += -fsection-anchors >> >> +# gcc 4.8 spits out false positives for default -O3 >> +# disable these for 4.8 and revisit when we upgrade to newer ver >> +cflags-$(is_gcc48) += $(call cc-disable-warning,maybe-uninitialized,) >> + >> cflags-$(CONFIG_ARC_HAS_LLSC) += -mlock >> cflags-$(CONFIG_ARC_HAS_SWAPE) += -mswape > > Is this any better with gcc-4.9 or gcc-5? I don't think there's a production ARC toolchain with gcc 4.9 which we can use yet - Claudiu is still in the the middle of upstreaming the new ARC HS port bits so things are still in flight there. These tools are off of github ! Maybe it's better to add the flag to > the line that adds -O3 for consistency. We do the same thing for -Os in the > global Makefile, as that triggers a similar load of warnings. Sure, but I prefer this to be only for gcc 4.8 as this warning seems to be healthy in small doses :-) At least it keeps the door open for future discussion with gcc guys ! The following nested construct actually works - does that look OK to you ? ARCH_CFLAGS += -O3 $(call cc-ifversion, -lt, 0408, $(call cc-disable-warning,maybe-uninitialized,)) Thx, -Vineet > > Arnd > -- > To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >