[Bug c++/103379] New: [12 Regression] ICE: tree check: expected class 'type', have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544

[Bug c++/103379] New: [12 Regression] ICE: tree check: expected class 'type', have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103379

            Bug ID: 103379
           Summary: [12 Regression] ICE: tree check: expected class
                    'type', have 'declaration' (namespace_decl) in
                    comptypes, at cp/typeck.c:1544
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

g++-12.0.0-alpha20211121 snapshot (g:da17c304e22ba256eba0b03710aa329115163b08)
ICEs when compiling the following testcase, extracted from
test/CXX/dcl.dcl/basic.namespace/namespace.udecl/p7-cxx20.cpp from the clang
13.0.0 test suite, w/ -std=c++20:

namespace Nine {
namespace Q {
enum class Bob { a };
using Bob::a;
}

struct Foo {
  using Q::a;
  using Q::Bob::a;
};
}

% gcc-12.0.0 -std=c++20 -c tjgp3kjm.cpp
tjgp3kjm.cpp:9:17: internal compiler error: tree check: expected class 'type',
have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544
    9 |   using Q::Bob::a;
      |                 ^
0x862e17 tree_class_check_failed(tree_node const*, tree_code_class, char
const*, int, char const*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/tree.c:8752
0x72ded8 tree_class_check(tree_node*, tree_code_class, char const*, int, char
const*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/tree.h:3564
0x72ded8 comptypes(tree_node*, tree_node*, int)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/typeck.c:1544
0xa84878 push_class_level_binding_1
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/name-lookup.c:5490
0xa84a1e push_class_level_binding(tree_node*, tree_node*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/name-lookup.c:5549
0xa84a1e pushdecl_class_level(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/name-lookup.c:5284
0xb62567 finish_member_declaration(tree_node*)
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/semantics.c:3562
0xa98b81 finish_using_decl
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:21338
0xadd229 cp_parser_using_declaration
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:21469
0xab55e6 cp_parser_member_specification_opt
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:26668
0xab55e6 cp_parser_class_specifier_1
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:25738
0xab7ab7 cp_parser_class_specifier
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:26055
0xab7ab7 cp_parser_type_specifier
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:19220
0xab8a54 cp_parser_decl_specifier_seq
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:15794
0xab99d7 cp_parser_simple_declaration
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:15042
0xaeb015 cp_parser_declaration
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:14855
0xaea4f9 cp_parser_toplevel_declaration
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:14876
0xaea4f9 cp_parser_declaration_seq_opt
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:14629
0xaea953 cp_parser_namespace_body
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:21250
0xaea953 cp_parser_namespace_definition
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20211121/work/gcc-12-20211121/gcc/cp/parser.c:21228

[Bug c++/103379] ICE: tree check: expected class 'type', have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103379

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-11-23
     Ever confirmed|0                           |1

--- Comment #1 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Confirmed, but clang++ accepts it, so probably valid code.

[Bug c++/103379] ICE: tree check: expected class 'type', have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103379

Martin Liška <marxin at gcc dot gnu.org> changed:

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

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Started to ICE after r11-5003-gd50310408f54e380, it was rejected before the
revision.

[Bug c++/103379] ICE: tree check: expected class 'type', have 'declaration' (namespace_decl) in comptypes, at cp/typeck.c:1544

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103379

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-invalid-code         |ice-on-valid-code

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Looks valid.