Re: [V2][PATCH 1/1] Add a new warning option -Wstrict-flex-arrays.

[Kees Cook <keescook@chromium.org>]

On Wed, Nov 30, 2022 at 02:25:56PM +0000, Qing Zhao wrote:
> '-Wstrict-flex-arrays'
>      Warn about inproper usages of flexible array members according to
>      the LEVEL of the 'strict_flex_array (LEVEL)' attribute attached to
>      the trailing array field of a structure if it's available,
>      otherwise according to the LEVEL of the option
>      '-fstrict-flex-arrays=LEVEL'.
> 
>      This option is effective only when LEVEL is bigger than 0.
>      Otherwise, it will be ignored with a warning.
> 
>      when LEVEL=1, warnings will be issued for a trailing array
>      reference of a structure that have 2 or more elements if the
>      trailing array is referenced as a flexible array member.
> 
>      when LEVEL=2, in addition to LEVEL=1, additional warnings will be
>      issued for a trailing one-element array reference of a structure if
>      the array is referenced as a flexible array member.
> 
>      when LEVEL=3, in addition to LEVEL=2, additional warnings will be
>      issued for a trailing zero-length array reference of a structure if
>      the array is referenced as a flexible array member.
> 
> At the same time, -Warray-bounds is updated:

Why is there both -Wstrict-flex-arrays and -Warray-bounds? I thought
only the latter was going to exist?

Are you trying to split code gen (-fstrict-flex-arrays) from warnings?
Is that needed?

-- 
Kees Cook