From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f65.google.com ([209.85.221.65]:45909 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725965AbfIDWky (ORCPT ); Wed, 4 Sep 2019 18:40:54 -0400 Date: Wed, 4 Sep 2019 15:40:50 -0700 From: Nathan Chancellor Subject: Re: [PATCH v3 1/2] kbuild: refactor scripts/Makefile.extrawarn Message-ID: <20190904224050.GA82176@archlinux-threadripper> References: <20190831162555.31887-1-yamada.masahiro@socionext.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Arnd Bergmann Cc: Masahiro Yamada , Linux Kbuild mailing list , Nick Desaulniers , Sedat Dilek , Michal Marek , clang-built-linux , "linux-kernel@vger.kernel.org" On Wed, Sep 04, 2019 at 11:46:45PM +0200, Arnd Bergmann wrote: > On Sat, Aug 31, 2019 at 6:26 PM Masahiro Yamada > wrote: > > > +# Some diagnostics enabled by default are noisy. > > +# Suppress them by using -Wno... except for W=1. > > + > > ifdef CONFIG_CC_IS_CLANG > > KBUILD_CFLAGS += -Wno-initializer-overrides > > KBUILD_CFLAGS += -Wno-format > > KBUILD_CFLAGS += -Wno-sign-compare > > KBUILD_CFLAGS += -Wno-format-zero-length > > endif > > FWIW, I just found out I missed a bug that clang failed to warn about > because of the -Wno-format. Apparently gcc warns only about type > mismatches that result in incompatible calling conventions (e.g. > int vs int64_t) but not smaller types (int, short) that get converted to an > int anyway. Passing -Wno-format turns both off. > > Arnd Hi Arnd, This has been fixed in clang 10.0.0 but this areas has not been updated as nobody has sent a patch yet: https://github.com/ClangBuiltLinux/linux/issues/378#issuecomment-524411147 Cheers, Nathan