From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF705C4338F for ; Mon, 2 Aug 2021 20:29:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E6E1610FB for ; Mon, 2 Aug 2021 20:29:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231368AbhHBU3t (ORCPT ); Mon, 2 Aug 2021 16:29:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:54950 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229729AbhHBU3s (ORCPT ); Mon, 2 Aug 2021 16:29:48 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3C577610A8; Mon, 2 Aug 2021 20:29:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627936178; bh=ARh9DG4tmIsdrfUtUTPBkpcqMfcJVlCT5toIiYasvPk=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=TX40QJ9dwI2EgMqrYCge7MFeyMWOcZvO5Noztf2D6DAXlAtwAWisLF3hgaz04HbCj iXNjxejwW6eyNbTzNZft0w7sK2wfKxFaNu2MxBROGxltUUdFta8fjBJlDpntD9URP6 rmHKP0V/JckHQzBePnr98wf8ZM3UJVC8dDEpwgqMwlMVUKudwcwf0yob0vRsJHeRDW 9o/Oop5xbrACDKfDnKv6N2xm9pL3Ou3vNr6erXw9mUdlmo8MnZ2wC4+zslNcTv7mG9 P6qAZ/HErMbjhqhdTr2HCbZUpDY7c72/YOYDLheGXz1KpHgTSk43rrLFxmYrJ/IvVH koo5g8srn89QA== Subject: Re: [PATCH v2] compiler_attributes.h: move __compiletime_{error|warning} To: Nick Desaulniers , Miguel Ojeda Cc: Andrew Morton , Kees Cook , Marco Elver , Masahiro Yamada , Luc Van Oostenryck , Arvind Sankar , Will Deacon , Sami Tolvanen , Arnd Bergmann , Ard Biesheuvel , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com References: <20210802202326.1817503-1-ndesaulniers@google.com> From: Nathan Chancellor Message-ID: <1847b77a-093a-ce59-5c3b-1a21d3bb66c7@kernel.org> Date: Mon, 2 Aug 2021 13:29:36 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210802202326.1817503-1-ndesaulniers@google.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/2/2021 1:23 PM, 'Nick Desaulniers' via Clang Built Linux wrote: > I'm working on adding support for __attribute__((__error__(""))) and > __attribute__((__warning__(""))) to Clang. To make use of these in > __compiletime_error and __compiletime_warning (as used by BUILD_BUG and > friends) for newer clang and detect/fallback for older versions of > clang, move these to compiler_attributes.h and guard them with > __has_attribute preprocessor guards. > > Link: https://reviews.llvm.org/D106030 > Link: https://bugs.llvm.org/show_bug.cgi?id=16428 > Link: https://github.com/ClangBuiltLinux/linux/issues/1173 > Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor One comment below, please carry my tag forward in further revisions unless they are significant. > --- > Changes v1 -> v2: > * Use __warning__ rather than warning in __has_attribute check, as per > Nathan. > * Don't sort existing __GCC4_has_attribute_* defines. > > include/linux/compiler-gcc.h | 3 --- > include/linux/compiler_attributes.h | 24 ++++++++++++++++++++++++ > include/linux/compiler_types.h | 6 ------ > 3 files changed, 24 insertions(+), 9 deletions(-) > > diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h > index cb9217fc60af..21c36b69eb06 100644 > --- a/include/linux/compiler-gcc.h > +++ b/include/linux/compiler-gcc.h > @@ -43,9 +43,6 @@ > > #define __compiletime_object_size(obj) __builtin_object_size(obj, 0) > > -#define __compiletime_warning(message) __attribute__((__warning__(message))) > -#define __compiletime_error(message) __attribute__((__error__(message))) > - > #if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__) > #define __latent_entropy __attribute__((latent_entropy)) > #endif > diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h > index 67c5667f8042..fb08b843ab47 100644 > --- a/include/linux/compiler_attributes.h > +++ b/include/linux/compiler_attributes.h > @@ -30,6 +30,7 @@ > # define __GCC4_has_attribute___assume_aligned__ 1 > # define __GCC4_has_attribute___copy__ 0 > # define __GCC4_has_attribute___designated_init__ 0 > +# define __GCC4_has_attribute___error__ 1 > # define __GCC4_has_attribute___externally_visible__ 1 > # define __GCC4_has_attribute___no_caller_saved_registers__ 0 > # define __GCC4_has_attribute___noclone__ 1 > @@ -39,6 +40,7 @@ > # define __GCC4_has_attribute___no_sanitize_undefined__ 1 > # define __GCC4_has_attribute___no_sanitize_coverage__ 0 > # define __GCC4_has_attribute___fallthrough__ 0 > +# define __GCC4_has_attribute___warning__ 1 > #endif > > /* > @@ -138,6 +140,17 @@ > # define __designated_init > #endif > > +/* > + * Optional: only supported since clang >= 13.0 Are you planning on petitioning for D106030 to be applied to release/13.x when it is merged into main? If not, this should be updated to 14.0.0 since that is main's current version. > + * > + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-error-function-attribute > + */ > +#if __has_attribute(__error__) > +# define __compiletime_error(msg) __attribute__((__error__(msg))) > +#else > +# define __compiletime_error(msg) > +#endif > + > /* > * Optional: not supported by clang > * > @@ -299,6 +312,17 @@ > */ > #define __must_check __attribute__((__warn_unused_result__)) > > +/* > + * Optional: only supported since clang >= 13.0 > + * > + * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-warning-function-attribute > + */ > +#if __has_attribute(__warning__) > +# define __compiletime_warning(msg) __attribute__((__warning__(msg))) > +#else > +# define __compiletime_warning(msg) > +#endif > + > /* > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-weak-function-attribute > * gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-weak-variable-attribute > diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h > index e4ea86fc584d..b6ff83a714ca 100644 > --- a/include/linux/compiler_types.h > +++ b/include/linux/compiler_types.h > @@ -294,12 +294,6 @@ struct ftrace_likely_data { > #ifndef __compiletime_object_size > # define __compiletime_object_size(obj) -1 > #endif > -#ifndef __compiletime_warning > -# define __compiletime_warning(message) > -#endif > -#ifndef __compiletime_error > -# define __compiletime_error(message) > -#endif > > #ifdef __OPTIMIZE__ > # define __compiletime_assert(condition, msg, prefix, suffix) \ >