Re: [PATCH net-next 1/8] tools: ynl: fix render-max for flags definition

[Jakub Kicinski <kuba@kernel.org>]

On Tue,  7 Mar 2023 15:53:58 +0100 Lorenzo Bianconi wrote:
> Properly manage render-max property for flags definition type
> introducing mask value and setting it to (last_element << 1) - 1
> instead of adding max value set to last_element + 1
> 
> Fixes: be5bea1cc0bf ("net: add basic C code generators for Netlink")
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>  tools/net/ynl/ynl-gen-c.py | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/net/ynl/ynl-gen-c.py b/tools/net/ynl/ynl-gen-c.py
> index 274e9c566f61..f2e41dd962d4 100755
> --- a/tools/net/ynl/ynl-gen-c.py
> +++ b/tools/net/ynl/ynl-gen-c.py
> @@ -1995,9 +1995,14 @@ def render_uapi(family, cw):
>  
>              if const.get('render-max', False):
>                  cw.nl()
> -                max_name = c_upper(name_pfx + 'max')
> -                cw.p('__' + max_name + ',')
> -                cw.p(max_name + ' = (__' + max_name + ' - 1)')
> +                if const['type'] == 'flags':
> +                    max_name = c_upper(name_pfx + 'mask')
> +                    max_val = f' = {(entry.user_value() << 1) - 1},'

Hm, why not use const.get_mask() here? Rather than the last entry?

> +                    cw.p(max_name + max_val)
> +                else:
> +                    max_name = c_upper(name_pfx + 'max')
> +                    cw.p('__' + max_name + ',')
> +                    cw.p(max_name + ' = (__' + max_name + ' - 1)')
>              cw.block_end(line=';')
>              cw.nl()
>          elif const['type'] == 'const':