Created attachment 14856 [details]
Use with gdb to demonstrate bug.

When the last element of a C language struct is a zero length array, the evaluation of sizeof(*(struct S*)pointer) does not match sizeof(struct S).

> Breakpoint 1, fn (ps=0x7fffffffe250) at demo-sizeof-bug.c:15
> 15              printf("ps = %p\n", ps);
> (gdb) p sizeof(*ps)
> $1 = 7
> (gdb) p sizeof(struct S)
> $2 = 8
> (gdb) ptype/o *ps
> /* offset      |    size */  type = struct S {
> /*      0      |       4 */    int32_t f1;
> /*      4      |       2 */    int16_t f2;
> /*      6      |       1 */    int8_t f3;
> /*      7      |       0 */    int8_t f4[];
>                              /* total size (bytes):    7 */