[Bug c/122496] New: counted-by attribute is not supported correctly for a FAM embedded in an anonymous structure

[qinzhao at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122496

            Bug ID: 122496
           Summary: counted-by attribute is not supported correctly for a
                    FAM embedded in an anonymous structure
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: qinzhao at gcc dot gnu.org
  Target Milestone: ---

for example:
#define __counted_by(member) \
    __attribute__((__counted_by__(member)))

/* Only GCC complains. */
struct fam_in_struct {
    int count;
    struct {
        char a;
        char fam[] __counted_by(count);
    };
};
[counted_by_bug]$ sh t
/home/opc/Install/latest-d/bin/gcc -O1 t1.c
t1.c:9:14: error: argument ‘count’ to the ‘counted_by’ attribute is not a field
declaration in the same structure as ‘fam’
    9 |         char fam[] __counted_by(count);
      |              ^~~