https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107952
--- Comment #8 from Siddhesh Poyarekar <siddhesh at gcc dot gnu.org> ---
(In reply to qinzhao from comment #7)
> (In reply to Richard Biener from comment #1)
> > GCC considered this as a flex-array.
>
> do you mean for the following example:
>
> typedef struct {
> char pad;
> char data[];
> } F2;
>
> typedef struct {
> unsigned pad;
> F2 flex;
> } S2;
>
> although C standard disallow the above, GCC extension treats S2.flex.data as
> a flex-array?
>
> How about:
>
> typedef struct {
> char pad;
> char data[];
> } F2;
>
> typedef struct {
> F2 flex;
> unsigned pad;
> } S2;
>
> do we have any documentation on this Gcc extension?
There's an open bug to document these semantics:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77650
