[Bug debug/109161] New: Bad CTF generated for stub in function scope

["ibhagat at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109161

            Bug ID: 109161
           Summary: Bad CTF generated for stub in function scope
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ibhagat at gcc dot gnu.org
  Target Milestone: ---

$ cat t.c 
void set_cpu_arch (void) {
    typedef struct arch_stack_entry {
        const struct arch_stack_entry *prev;
    } arch_stack_entry;
    static arch_stack_entry *arch_stack_top;
}

$ gcc -gctf -g3 -c t.c

$ objdump --ctf=.ctf t.o will hang.

The hang is because the compiler spits incorrect CTF. 

Byte offsets (which point to the location of the various sub-sections in the
CTF section) encoded in the CTF header as seen via poke:
  ...
  cth_funcoff=0U#B,
  cth_objtidxoff=4U#B,
  cth_funcidxoff=4U#B,
  cth_varoff=8U#B,
  cth_typeoff=8U#B,
  cth_stroff=96U#B,
  ...

 -- The generated CTF section has one function object, and no variables as can
be seen from the offsets in the header. This is OK. 
 --There are however, generated types; Further, a subset of which are incorrect
(see below).

(poke) ctf_dump_all_types(ctf)
Types:
   1:  (kind 1) integer void (size 0) (signed)
   2:  (kind 5) function set_cpu_arch --> ID 1: (kind 1) integer void (size 0)
   3:  (kind 6) struct arch_stack_entry (size 8)
        [0U#b] prev (ID 5)
        [0U#b]  (ID 3)
   4:  (kind 12) const  --> ID 3: (kind 6) struct arch_stack_entry (size 8)
   5:  (kind 3) pointer  --> ID 4: (kind 12) const  --> ID 3: (kind 6) struct
arch_stack_entry (size 8)

[Problem #1] A struct with two members, one of which is unnamed.  The type as
defined by the user has one member named prev in the struct => The generated
CTF is incorrect.
[Problem #2] Well, why is there any generated CTF at all ?  Both the variable
and the defined type are function-scope; In CTF, only top-level types,
functions, variables are to be described.