> On Aug 31, 2022, at 3:52 PM, Joseph Myers <jos...@codesourcery.com> wrote:
>
> On Wed, 31 Aug 2022, Qing Zhao wrote:
>
>> Does the above mean that -std=gnu89 does not support C99 flexible array
>> member, then
>
> No.
>
> Flexible array members are supported by GCC in all C standards modes. The
> C90 standard doesn't support them, but that's irrelevant to what GCC
> supports; it just means a diagnostic is required for strict conformance in
> pre-C99 modes.
Okay.
>
>> When -std=gnu89 + -fstrict-flex-array=3 (ONLY C99 flexible array member
>> [] is treated as a valid flexible array) present together,
>
> That seems reasonable enough without a warning. If people want a warning
> for flexible array members in older language modes, they can use
> -pedantic; I don't think we need to warn for any particular
> -fstrict-flex-array modes there.
So, you mean,
1. GCC with -std=gnu89 support all [0], [1], and [] as Flexible array member;
2. Therefore. -std=gnu89 + -fstrict-flex-array=3 does not need a warning;
?
Then, how about:
-std=c89:
1. GCC with -std=c89 also support all [0], [1], and [] as Flexible array member;
2, therefore, -std=c89 + -fstrict-flex-array does not need a warning too.
?
Qing
>
> --
> Joseph S. Myers
> jos...@codesourcery.com
