On Fri, Mar 4, 2022 at 2:47 PM Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> wrote:
>
> From: Nathan Chancellor <nathan@xxxxxxxxxx>
>
> Add __diag macros similar to those in compiler-gcc.h, so that warnings
> that need to be adjusted for specific cases but not globally can be
> ignored when building with clang.
>
> Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
> Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> Cc: llvm@xxxxxxxxxxxxxxx
> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
> [ Kartikeya: wrote commit message ]
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> ---
> include/linux/compiler-clang.h | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> index 3c4de9b6c6e3..f1aa41d520bd 100644
> --- a/include/linux/compiler-clang.h
> +++ b/include/linux/compiler-clang.h
The equivalent functionality for GCC has
357 #ifndef __diag_GCC
358 #define __diag_GCC(version, severity, string)
359 #endif
in include/linux/compiler_types.h. Should this patch as well? (at
least #define __diag_clang`)?
> @@ -68,3 +68,25 @@
>
> #define __nocfi __attribute__((__no_sanitize__("cfi")))
> #define __cficanonical __attribute__((__cfi_canonical_jump_table__))
> +
> +/*
> + * Turn individual warnings and errors on and off locally, depending
> + * on version.
> + */
> +#define __diag_clang(version, severity, s) \
> + __diag_clang_ ## version(__diag_clang_ ## severity s)
> +
> +/* Severity used in pragma directives */
> +#define __diag_clang_ignore ignored
> +#define __diag_clang_warn warning
> +#define __diag_clang_error error
These severities match GCC. I wonder if rather than copy+pasting these
over, we could rework __diag_ignore, __diag_warn, and __diag_error to
not invoke a compiler-suffixed macro and rather pass the compiler
along (or make it implicit since we know CONFIG_CC_IS_CLANG vs
CONFIG_CC_IS_GCC)? We can probably land this than follow up on better
code-reuse between compilers for diagnostics.
> +
> +#define __diag_str1(s) #s
> +#define __diag_str(s) __diag_str1(s)
> +#define __diag(s) _Pragma(__diag_str(clang diagnostic s))
> +
> +#if CONFIG_CLANG_VERSION >= 110000
> +#define __diag_clang_11(s) __diag(s)
> +#else
> +#define __diag_clang_11(s)
> +#endif
> --
> 2.35.1
>
--
Thanks,
~Nick Desaulniers
