From: Nathan Chancellor <nathan@kernel.org>
To: Nick Desaulniers <ndesaulniers@google.com>,
Miguel Ojeda <ojeda@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>, Marco Elver <elver@google.com>,
Masahiro Yamada <masahiroy@kernel.org>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Arvind Sankar <nivedita@alum.mit.edu>,
Will Deacon <will@kernel.org>,
Sami Tolvanen <samitolvanen@google.com>,
Arnd Bergmann <arnd@arndb.de>, Ard Biesheuvel <ardb@kernel.org>,
linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: Re: [PATCH v2] compiler_attributes.h: move __compiletime_{error|warning}
Date: Mon, 2 Aug 2021 13:29:36 -0700 [thread overview]
Message-ID: <1847b77a-093a-ce59-5c3b-1a21d3bb66c7@kernel.org> (raw)
In-Reply-To: <20210802202326.1817503-1-ndesaulniers@google.com>
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 <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
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) \
>
next prev parent reply other threads:[~2021-08-02 20:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-02 20:23 [PATCH v2] compiler_attributes.h: move __compiletime_{error|warning} Nick Desaulniers
2021-08-02 20:29 ` Nathan Chancellor [this message]
2021-08-04 17:43 ` Nick Desaulniers
2021-08-04 17:48 ` Miguel Ojeda
2021-09-02 18:26 ` Nick Desaulniers
2021-08-03 6:42 ` Kees Cook
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1847b77a-093a-ce59-5c3b-1a21d3bb66c7@kernel.org \
--to=nathan@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=ardb@kernel.org \
--cc=arnd@arndb.de \
--cc=clang-built-linux@googlegroups.com \
--cc=elver@google.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luc.vanoostenryck@gmail.com \
--cc=masahiroy@kernel.org \
--cc=ndesaulniers@google.com \
--cc=nivedita@alum.mit.edu \
--cc=ojeda@kernel.org \
--cc=samitolvanen@google.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).