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 14CFA3884FBB; Wed, 14 Dec 2022 18:18:05 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 14CFA3884FBB
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1671041885;
	bh=Pkji8iK7ZSIag8OQtfp3GSu0dexvO8qfSavguoXaej4=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=f/qRfoT/XDVUldHUAslFutHoOnkrT12B5EkQcUjmnv/nlWv4dLp1xZ3kFNU70ujPy
	 4D8/TTm8HAVEQY3WEdzT3kfE7W820qZOiu4hnHpJDJpFH3mkFduaiuX7DeDOiLsple
	 Mx4/FP43qrU8JmiE+ecpEZCi38LdQMuX4b5gR+xw=
From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/108099] [12/13 Regression] ICE with type alias with `signed
 __int128_t`
Date: Wed, 14 Dec 2022 18:18:04 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 12.2.0
X-Bugzilla-Keywords: ice-on-invalid-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: jakub at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 11.4
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cc
Message-ID: <bug-108099-4-T0ZNOprJMB@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-108099-4@http.gcc.gnu.org/bugzilla/>
References: <bug-108099-4@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=3D108099

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jason at gcc dot gnu.org

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r12-8173-ge580f81d22d61153564959f08d9a6d3bcc7fd386
For
using u128 =3D unsigned __int128_t;
auto a =3D sizeof (u128);
it doesn't ICE but changes behavior, before that commit a was 16, now it is=
 4.
The reason for the ICE as well as 4 in there is because r12-8173 does:
+             type =3D DECL_ORIGINAL_TYPE (typedef_decl);
+             typedef_decl =3D NULL_TREE;
which is fine for user typedefs, but for the internally created typedefs li=
ke
__int128_t, __uint128_t, __builtin_va_list, dunno if others too
DECL_ORIGINAL_TYPE
is NULL.
So, the question is if we should fix it by tweaking c-common.cc so that ins=
tead
of say:
  if (targetm.scalar_mode_supported_p (TImode))
    lang_hooks.decls.pushdecl (build_decl (UNKNOWN_LOCATION,
                                           TYPE_DECL,
                                           get_identifier ("__int128_t"),
                                           intTI_type_node));
do
  if (targetm.scalar_mode_supported_p (TImode))
    {
      tree decl =3D build_decl (UNKNOWN_LOCATION, TYPE_DECL,
                              get_identifier ("__int128_t"),
                              intTI_type_node);
      DECL_ORIGINAL_TYPE (decl) =3D intTI_type_node;
      lang_hooks.decls.pushdecl (decl);
    }
etc., or if it wouldn't be better or at least easier to:
--- gcc/cp/decl.cc.jj   2022-12-05 11:10:37.528674260 +0100
+++ gcc/cp/decl.cc      2022-12-14 19:16:40.242926374 +0100
@@ -12442,7 +12442,8 @@ grokdeclarator (const cp_declarator *dec
              pedwarn (loc, OPT_Wpedantic, "%qs specified with %qT",
                       key, type);
              ok =3D !flag_pedantic_errors;
-             type =3D DECL_ORIGINAL_TYPE (typedef_decl);
+             if (DECL_ORIGINAL_TYPE (typedef_decl))
+               type =3D DECL_ORIGINAL_TYPE (typedef_decl);
              typedef_decl =3D NULL_TREE;
            }
          else if (declspecs->decltype_p)
I'm going to test the latter.=