From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-f68.google.com ([209.85.210.68]:34149 "EHLO mail-ot1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726750AbgBSEyh (ORCPT ); Tue, 18 Feb 2020 23:54:37 -0500 From: Nathan Chancellor Subject: [PATCH 6/6] kbuild: Enable -Wtautological-compare Date: Tue, 18 Feb 2020 21:54:23 -0700 Message-Id: <20200219045423.54190-7-natechancellor@gmail.com> In-Reply-To: <20200219045423.54190-1-natechancellor@gmail.com> References: <20200219045423.54190-1-natechancellor@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Masahiro Yamada , Michal Marek , Arnd Bergmann , Steven Rostedt , Ingo Molnar , Jason Baron , Catalin Marinas , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, clang-built-linux@googlegroups.com, Nathan Chancellor Currently, we disable -Wtautological-compare, which in turn disables a bunch of more specific tautological comparison warnings that are useful for the kernel (see clang's documentation below). Now that all of the major/noisy warnings have been fixed, enable -Wtautological-compare so that more issues can be caught at build time. -Wtautological-constant-out-of-range-compare is kept disabled because there are places in the kernel where a constant or variable size can change based on the kernel configuration; these are not fixed in a clean/concise way and they are almost always harmless so this one subwarning is kept disabled. Link: https://github.com/ClangBuiltLinux/linux/issues/488 Link: http://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html#wtautological-compare Signed-off-by: Nathan Chancellor --- Makefile | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/Makefile b/Makefile index b954c304c479..99080c57a1cb 100644 --- a/Makefile +++ b/Makefile @@ -742,8 +742,7 @@ ifdef CONFIG_CC_IS_CLANG KBUILD_CPPFLAGS += -Qunused-arguments KBUILD_CFLAGS += -Wno-format-invalid-specifier KBUILD_CFLAGS += -Wno-gnu -# Quiet clang warning: comparison of unsigned expression < 0 is always false -KBUILD_CFLAGS += -Wno-tautological-compare +KBUILD_CFLAGS += -Wno-tautological-constant-out-of-range-compare # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the # source of a reference will be _MergedGlobals and not on of the whitelisted names. # See modpost pattern 2 -- 2.25.1