From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id 88B253858D35; Thu, 16 Mar 2023 20:45:46 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 88B253858D35
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1678999546;
	bh=Xyuw1fzvHNyCuZGSZ4BIX65GGY39orTHUfFf1iAwLNo=;
	h=From:To:Subject:Date:From;
	b=UZCijELXhHLntHHfye1zwoTJUC+TV2VPAC93ykhUkvsXmt7B0Ad56tjoInoIHKSEl
	 XB4lt87Tojcgn+NO7KueYfiiO/AuQggz4dFzFdCx4bvQcLHUnr4KcDN9W5q7SbyHR8
	 7MRjEghsBN6a913iCShVoscUTJzuzmIJsBrLxmyk=
From: "ibhagat at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug debug/109161] New: Bad CTF generated for stub in function scope
Date: Thu, 16 Mar 2023 20:45:46 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: debug
X-Bugzilla-Version: 13.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: ibhagat at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-109161-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109161

            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=20
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=3D.ctf t.o will hang.

The hang is because the compiler spits incorrect CTF.=20

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=3D0U#B,
  cth_objtidxoff=3D4U#B,
  cth_funcidxoff=3D4U#B,
  cth_varoff=3D8U#B,
  cth_typeoff=3D8U#B,
  cth_stroff=3D96U#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.=20
 --There are however, generated types; Further, a subset of which are incor=
rect
(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) stru=
ct
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 =3D> The genera=
ted
CTF is incorrect.
[Problem #2] Well, why is there any generated CTF at all ?  Both the variab=
le
and the defined type are function-scope; In CTF, only top-level types,
functions, variables are to be described.=