[Bug c/109828] C2x:static compound literal (with flexible array) in initializer leads to invalid size and ICE

["yann at droneaud dot fr" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109828

--- Comment #2 from Yann Droneaud <yann at droneaud dot fr> ---
(In reply to Yann Droneaud from comment #0)
> The following code is badly compiled by GCC 13.1:
> 
>     struct s { int i; char c[]; };
> 
>     const struct s s = { .c = "0", };
>     const struct s *r = &(constexpr struct s) { .c = "1", };
>     const struct s *t = &(static struct s) { .c = "2", };
> 
> Targetting x86-64 / amd64, compiling this with gcc -std=gnu2x -S, produces
> surprising large .zero directive:
> 
>     s: 
>         .zero   4
>         .string "0"
>     __compound_literal.0:
>         .zero   4
>         .string "1"
>         .zero   18446744073709551613
>         .zero   1
>     r:
>         .quad   __compound_literal.0
>     __compound_literal.1:
>         .zero   4
>         .string "2"
>         .zero   18446744073709551613
>         .zero   1
>     t:
>         .quad   __compound_literal.1
> 
>

When asked to assemble that, binutils' as complains:

    $ gcc -std=gnu2x nice.c -c
    /tmp/ccZEWv73.s: Assembler messages:
    /tmp/ccZEWv73.s:17: Warning: .space repeat count is zero, ignored
    /tmp/ccZEWv73.s:32: Warning: .space repeat count is zero, ignored