On Sat, Mar 05, 2022 at 04:16:43AM +0530, Kumar Kartikeya Dwivedi wrote:
> Add a __diag_ignore_all macro, to ignore warnings for both GCC and LLVM,
> without having to specify the compiler type and version. By default, GCC
> 8 and clang 11 are used. This will be used by bpf subsystem to ignore
> -Wmissing-prototypes warning for functions that are meant to be global
> functions so that they are in vmlinux BTF, but don't have a prototype.
>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
> ---
> include/linux/compiler-clang.h | 3 +++
> include/linux/compiler-gcc.h | 3 +++
> include/linux/compiler_types.h | 4 ++++
> 3 files changed, 10 insertions(+)
>
> diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h
> index f1aa41d520bd..babb1347148c 100644
> --- a/include/linux/compiler-clang.h
> +++ b/include/linux/compiler-clang.h
> @@ -90,3 +90,6 @@
> #else
> #define __diag_clang_11(s)
> #endif
> +
> +#define __diag_ignore_all(option, comment) \
> + __diag_clang(11, ignore, option)
> diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
> index ccbbd31b3aae..d364c98a4a80 100644
> --- a/include/linux/compiler-gcc.h
> +++ b/include/linux/compiler-gcc.h
> @@ -151,6 +151,9 @@
> #define __diag_GCC_8(s)
> #endif
>
> +#define __diag_ignore_all(option, comment) \
> + __diag_GCC(8, ignore, option)
While this approach will work for clang, it doesn't seem scalable for
GCC. Documentation/process/changes.rst documents that we support gcc
5.1+. This approach will only disable diagnostics for gcc 8+.
> +
> /*
> * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
> * attribute) do not work, and must be disabled.
> diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
> index 3f31ff400432..8e5d2f50f951 100644
> --- a/include/linux/compiler_types.h
> +++ b/include/linux/compiler_types.h
> @@ -371,4 +371,8 @@ struct ftrace_likely_data {
> #define __diag_error(compiler, version, option, comment) \
> __diag_ ## compiler(version, error, option)
>
> +#ifndef __diag_ignore_all
> +#define __diag_ignore_all(option, comment)
> +#endif
> +
> #endif /* __LINUX_COMPILER_TYPES_H */
> --
> 2.35.1
>
