Re: [PATCH v3 13/14] lib/zstd: Convert constants to defines

[Nick Terrell <terrelln@fb.com>]

> On Jan 22, 2021, at 1:58 AM, Nikolay Borisov <nborisov@suse.com> wrote:
> 
> Those constants are really used internally by zstd and including
> linux/zstd.h into users results in the following warnings:
> 
> In file included from fs/btrfs/zstd.c:19:
> ./include/linux/zstd.h:798:21: warning: ‘ZSTD_skippableHeaderSize’ defined but not used [-Wunused-const-variable=]
>  798 | static const size_t ZSTD_skippableHeaderSize = 8;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:796:21: warning: ‘ZSTD_frameHeaderSize_max’ defined but not used [-Wunused-const-variable=]
>  796 | static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:795:21: warning: ‘ZSTD_frameHeaderSize_min’ defined but not used [-Wunused-const-variable=]
>  795 | static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
>      |                     ^~~~~~~~~~~~~~~~~~~~~~~~
> ./include/linux/zstd.h:794:21: warning: ‘ZSTD_frameHeaderSize_prefix’ defined but not used [-Wunused-const-variable=]
>  794 | static const size_t ZSTD_frameHeaderSize_prefix = 5;
> 
> So fix those warnings by turning the constants into defines.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> ---
> include/linux/zstd.h | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/include/linux/zstd.h b/include/linux/zstd.h
> index 249575e2485f..e87f78c9b19c 100644
> --- a/include/linux/zstd.h
> +++ b/include/linux/zstd.h
> @@ -791,11 +791,11 @@ size_t ZSTD_DStreamOutSize(void);
> /* for static allocation */
> #define ZSTD_FRAMEHEADERSIZE_MAX 18
> #define ZSTD_FRAMEHEADERSIZE_MIN  6
> -static const size_t ZSTD_frameHeaderSize_prefix = 5;
> -static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
> -static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
> +#define ZSTD_frameHeaderSize_prefix 5
> +#define ZSTD_frameHeaderSize_min ZSTD_FRAMEHEADERSIZE_MIN
> +#define ZSTD_frameHeaderSize_max ZSTD_FRAMEHEADERSIZE_MAX
> /* magic number + skippable frame length */
> -static const size_t ZSTD_skippableHeaderSize = 8;
> +#define ZSTD_skippableHeaderSize 8
> 
> 
> /*-*************************************
This looks good to me! We removed these constants from the upstream header a
while ago, for similar reasons.

You can add:

Reviewed-by: Nick Terrell <terrelln@fb.com>

-Nick