[Bug c++/99811] New: ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[Bug c++/99811] New: ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

            Bug ID: 99811
           Summary: ICE: tree check: accessed elt 2 of 'tree_vec' with 1
                    elts in tsubst_pack_expansion, at cp/pt.c:13002
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hewillk at gmail dot com
  Target Milestone: ---

https://godbolt.org/z/shj7Tr65M

related to PR 99809:

#include <concepts>

template <typename... Ts>
auto f(Ts...) {
  return []<typename... Us>(std::same_as<Ts> auto...) {};
}

int main() {
  f(0, 0.5)();
}

<source>:9:12: internal compiler error: tree check: accessed elt 2 of
'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002
    9 |   f(0, 0.5)();
      |   ~~~~~~~~~^~
0x1cfb7f9 internal_error(char const*, ...)
        ???:0
0x67bcb2 tree_vec_elt_check_failed(int, int, char const*, int, char const*)
        ???:0
0x93095c tsubst_pack_expansion(tree_node*, tree_node*, int, tree_node*)
        ???:0
0x73efca constraints_satisfied_p(tree_node*, tree_node*)
        ???:0
0x954963 fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, conversion**, bool,
bool)
        ???:0
0x6e225e build_op_call(tree_node*, vec<tree_node*, va_gc, vl_embed>**, int)
        ???:0
0x980ae5 finish_call_expr(tree_node*, vec<tree_node*, va_gc, vl_embed>**, bool,
bool, int)
        ???:0
0x8e12ad c_parse_file()
        ???:0
0xa600a2 c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[hewillk at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> ---
same form with the different error message:

https://godbolt.org/z/hE9n6eEMT

#include <concepts>

template <typename... Ts>
auto f(Ts...) {
  return []<std::same_as<Ts> auto> {};
}

int main() {
  f(0).template operator()<0>();
}


<source>:9:30: internal compiler error: tree check: accessed elt 1 of
'tree_vec' with 0 elts in hash, at cp/constraint.cc:2522
    9 |   f(0).template operator()<0>();
      |   ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~
0x1cfb7f9 internal_error(char const*, ...)
        ???:0
0x67bcb2 tree_vec_elt_check_failed(int, int, char const*, int, char const*)
        ???:0
0x73fc50 sat_hasher::hash(sat_entry*)
        ???:0
0x73b2b7 satisfaction_cache::satisfaction_cache(tree_node*, tree_node*,
sat_info)
        ???:0
0x73efca constraints_satisfied_p(tree_node*, tree_node*)
        ???:0
0x909bbe do_auto_deduction(tree_node*, tree_node*, tree_node*, int,
auto_deduction_context, tree_node*, int)
        ???:0
0x954187 fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node*
const*, unsigned int, tree_node*, unification_kind_t, int, conversion**, bool,
bool)
        ???:0
0x6dec99 build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc,
vl_embed>**, tree_node*, int, tree_node**, int)
        ???:0
0x8e12ad c_parse_file()
        ???:0
0xa600a2 c_common_parse_file()
        ???:0
Please submit a full bug report,
with preprocessed source if appropriate.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|11.1.0                      |

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The first testcase is fixed in GCC 11+ while the second testcase still ICEs on
the trunk.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|ice-on-invalid-code         |ice-on-valid-code
   Target Milestone|---                         |11.3
   Last reconfirmed|                            |2021-12-14
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
All reduced to:

template<typename T, typename U> concept C = sizeof(T) == 0;

template<typename T> void g5() {
[]() -> C<T> auto{ return T();  }();
}
template void g5<int>();

Confirmed.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.1.0
           Keywords|ice-on-valid-code           |ice-on-invalid-code,
                   |                            |needs-bisection

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Actually the original testcase seems to be fixed in GCC 11.
While the one in comment #1 and #3 are a regression; and recorded as PR 103341.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|11.3                        |---

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|needs-bisection             |
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |ppalka at gcc dot gnu.org

--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
Changed with r11-8065-g123b3e03c911a430.

[Bug c++/99811] ICE: tree check: accessed elt 2 of 'tree_vec' with 1 elts in tsubst_pack_expansion, at cp/pt.c:13002

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
   Target Milestone|---                         |11.0
         Resolution|---                         |FIXED

--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed.
Even though the original testcase was invalid, there was valid testcases which
was added with g++.dg/cpp2a/concepts-lambda16.C .