[Bug c++/98372] New: ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[Bug c++/98372] New: ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98372

            Bug ID: 98372
           Summary: ICE tree check: accessed elt 2 of ‘tree_vec’ with 1
                    elts in tsubst, at cp/pt.c:15500 since
                    r11-5942-g059da609fa8b3a08
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: nathan at gcc dot gnu.org
  Target Milestone: ---

Reduced from libcamera package:

$ cat ipa-key.ii
template <typename _Tp> using remove_pointer_t = typename _Tp ::type;
template <bool> struct enable_if;
template <bool _Cond, typename>
using enable_if_t = typename enable_if<_Cond>::type;
template <typename> bool is_convertible_v;
template <typename, unsigned long = 0> class Span;
template <typename T, unsigned long> class Span {
  using element_type = T;
  template <unsigned long N>
  Span(element_type (&arr)[N],
       enable_if_t<is_convertible_v<remove_pointer_t<decltype(data(arr))>>,
                   decltype(nullptr)>);
};
template <typename T> class Span<T> {
  using element_type = T;
  template <unsigned long N>
  Span(element_type (&arr)[N],
       enable_if_t<is_convertible_v<remove_pointer_t<decltype(data(arr))>>,
                   decltype(nullptr)>);
};

struct aaa
{
  Span<char> data0;
};

$ g++ ipa-key.ii -c
ipa-key.ii: In instantiation of ‘class Span<char>’:
ipa-key.ii:24:14:   required from here
ipa-key.ii:10:23: internal compiler error: tree check: accessed elt 2 of
‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15511
   10 |   Span(element_type (&arr)[N],
      |        ~~~~~~~~~~~~~~~^~~~~~~
0x83963e tree_vec_elt_check_failed(int, int, char const*, int, char const*)
        /home/marxin/Programming/gcc/gcc/tree.c:10011
0x94f182 tree_vec_elt_check(tree_node*, int, char const*, int, char const*)
        /home/marxin/Programming/gcc/gcc/tree.h:3559
0xad3dae tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:15511
0xab7c28 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:20744
0xac10d8 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:19004
0xad5a83 tsubst_expr(tree_node*, tree_node*, int, tree_node*, bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:12247
0xad5a83 tsubst_template_arg(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:12258
0xad5a83 tsubst_template_arg(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:12246
0xad5b98 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:13316
0xad4c57 tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:15395
0xad2d14 tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:15434
0xad2d14 tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:15434
0xabe8ef tsubst_decl
        /home/marxin/Programming/gcc/gcc/cp/pt.c:14461
0xab479f tsubst_copy
        /home/marxin/Programming/gcc/gcc/cp/pt.c:16514
0xab5f50 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:20609
0xab6703 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:19526
0xab6a03 tsubst_copy_and_build(tree_node*, tree_node*, int, tree_node*, bool,
bool)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:20033
0xad31ea tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:16086
0xad3296 tsubst(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:15979
0xad5b98 tsubst_template_args(tree_node*, tree_node*, int, tree_node*)
        /home/marxin/Programming/gcc/gcc/cp/pt.c:13316
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug c++/98372] ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98372

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.0
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2020-12-18
      Known to work|                            |10.2.0
      Known to fail|                            |11.0
             Status|UNCONFIRMED                 |NEW
           Priority|P3                          |P1

[Bug c++/98372] [11 Regression] ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98372

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |nathan at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

[Bug c++/98372] [11 Regression] ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98372

--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Nathan Sidwell <nathan@gcc.gnu.org>:

https://gcc.gnu.org/g:d61d2a5f3ce9238bad7cbd7733d90c6ec7ae5fbc

commit r11-6666-gd61d2a5f3ce9238bad7cbd7733d90c6ec7ae5fbc
Author: Nathan Sidwell <nathan@acm.org>
Date:   Thu Jan 14 05:15:33 2021 -0800

    c++: Fix erroneous parm comparison logic [PR 98372]

    I flubbed an application of De Morgan's law.  Let's just express the
    logic directly and let the compiler figure it out.  This bug made it
    look like pr52830 was fixed, but it is not.

            PR c++/98372
            gcc/cp/
            * tree.c (cp_tree_equal): Correct map_context logic.
            gcc/testsuite/
            * g++.dg/cpp0x/constexpr-52830.C: Restore dg-ice
            * g++.dg/template/pr98372.C: New.

[Bug c++/98372] [11 Regression] ICE tree check: accessed elt 2 of ‘tree_vec’ with 1 elts in tsubst, at cp/pt.c:15500 since r11-5942-g059da609fa8b3a08

[nathan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98372

Nathan Sidwell <nathan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #2 from Nathan Sidwell <nathan at gcc dot gnu.org> ---
fixed: * d61d2a5f3ce 2021-01-14 | c++: Fix erroneous parm comparison logic [PR
98372]