[Bug c++/103105] New: [11 Regression] ICE iterative_hash_template_arg, at cp/pt.c:1790

[Bug c++/103105] New: [11 Regression] ICE iterative_hash_template_arg, at cp/pt.c:1790

[jonathan.poelen at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

            Bug ID: 103105
           Summary: [11 Regression] ICE iterative_hash_template_arg, at
                    cp/pt.c:1790
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jonathan.poelen at gmail dot com
  Target Milestone: ---

$ cat test.cpp

template<class...>
struct list
{};

template<bool>
struct wrap_in_list_c
{};

template<class x, class... xs>
using wrap_in_list_if_convertible = wrap_in_list_c<
  1 != (... + requires { x() = xs(); })
>;

template<class... xs>
using foo = list<wrap_in_list_if_convertible<xs, xs...>...>;

using L = foo<int,int>;


$ g++ -std=c++20 test.cpp

test.cpp: In substitution of ‘template<class x, class ... xs> using
wrap_in_list_if_convertible = wrap_in_list_c<(1 != (... +requires{x()=
xs();}))> [with x = xs; xs = {xs ...}]’:
test.cpp:15:55:   required from here
test.cpp:10:7: internal compiler error: in iterative_hash_template_arg, at
cp/pt.c:1790
   10 | using wrap_in_list_if_convertible = wrap_in_list_c<
      |       ^~~~~~~~~~~~~~~~~~~~~~~~~~~
0x1797368 internal_error(char const*, ...)
        ???:0
0x67f8f9 fancy_abort(char const*, int, char const*)
        ???:0
0x7d5ec1 iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7d5d8f iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7d5e12 iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7d5d8f iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7d5d8f iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7d5ec1 iterative_hash_template_arg(tree_node*, unsigned int)
        ???:0
0x7e7d16 tsubst(tree_node*, tree_node*, int, tree_node*)
        ???:0
0x7f227c lookup_template_class(tree_node*, tree_node*, tree_node*, tree_node*,
int, int)
        ???:0
0x816d4d finish_template_type(tree_node*, tree_node*, int)
        ???:0
0x7ce2fe c_parse_file()
        ???:0
0x8a252d c_common_parse_file()
        ???:0


Works with g++-10: https://godbolt.org/z/KvM31Yq35

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11 Regression] ICE         |[11/12 Regression] ICE
                   |iterative_hash_template_arg |iterative_hash_template_arg
                   |, at cp/pt.c:1790           |with concepts and varagrs
                   |                            |template
      Known to fail|                            |11.1.0, 12.0
      Known to work|                            |10.3.0
   Target Milestone|---                         |11.3

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-11-06

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed, reduced testcase even further:
template<bool>class h{};
template<class... xs>
using j = h< 1 != (... + requires { xs(); }) >;
template<class... xs> using foo = j<xs...>;

I tried changing the requires to be something else but it didn't fail.

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11/12 Regression] ICE      |[11/12 Regression] ICE
                   |iterative_hash_template_arg |iterative_hash_template_arg
                   |with concepts and varagrs   |with concepts and varagrs
                   |template                    |template since
                   |                            |r11-3261-gb28b621ac67beee8
           Keywords|needs-bisection             |
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |ppalka at gcc dot gnu.org

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-3261-gb28b621ac67beee8.

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

Patrick Palka <ppalka at gcc dot gnu.org> changed:

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

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug c++/103105] [11/12 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Patrick Palka <ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:e2c7070ac7740508a7c49bfee9f895e216a272d6

commit r12-8110-ge2c7070ac7740508a7c49bfee9f895e216a272d6
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Apr 12 12:58:18 2022 -0400

    c++: requires-expr in pack expansion using pack [PR103105]

    Here after dependent substitution of {Ts...} into the alias 'wrap',
    since we never partially instantiate a requires-expr, we end up with a
    requires-expr whose REQUIRES_EXPR_EXTRA_ARGS contains an
    ARGUMENT_PACK_SELECT (which just resolves to the parameter pack Ts).
    Then when hashing the resulting dependent specialization of A, we crash
    from iterative_hash_template_arg since it deliberately doesn't handle
    ARGUMENT_PACK_SELECT.

    Like in r12-7102-gdb5f1c17031ad8, it seems the right fix here is to
    resolve ARGUMENT_PACK_SELECT arguments before storing them into an
    extra args tree (such as REQUIRES_EXPR).

            PR c++/103105

    gcc/cp/ChangeLog:

            * pt.cc (build_extra_args): Call preserve_args.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-requires29.C: New test.
            * g++.dg/cpp2a/concepts-requires29a.C: New test.

[Bug c++/103105] [11 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

Patrick Palka <ppalka at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |12.0
      Known to fail|12.0                        |
            Summary|[11/12 Regression] ICE      |[11 Regression] ICE
                   |iterative_hash_template_arg |iterative_hash_template_arg
                   |with concepts and varagrs   |with concepts and varagrs
                   |template since              |template since
                   |r11-3261-gb28b621ac67beee8  |r11-3261-gb28b621ac67beee8

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 12 so far.

[Bug c++/103105] [11 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105
Bug 103105 depends on bug 104008, which changed state.

Bug 104008 Summary: [11 Regression] New g++ folly compile error since r11-7931-ga2531859bf5bf6cf
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104008

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

[Bug c++/103105] [11 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:051d304ce8e2173bd0cb721ed91d4a1fefa61d87

commit r11-9839-g051d304ce8e2173bd0cb721ed91d4a1fefa61d87
Author: Patrick Palka <ppalka@redhat.com>
Date:   Tue Apr 12 12:58:18 2022 -0400

    c++: requires-expr in pack expansion using pack [PR103105]

    Here after dependent substitution of {Ts...} into the alias 'wrap',
    since we never partially instantiate a requires-expr, we end up with a
    requires-expr whose REQUIRES_EXPR_EXTRA_ARGS contains an
    ARGUMENT_PACK_SELECT (which just resolves to the parameter pack Ts).
    Then when hashing the resulting dependent specialization of A, we crash
    from iterative_hash_template_arg since it deliberately doesn't handle
    ARGUMENT_PACK_SELECT.

    Like in r12-7102-gdb5f1c17031ad8, it seems the right fix here is to
    resolve ARGUMENT_PACK_SELECT arguments before storing them into an
    extra args tree (such as REQUIRES_EXPR).

            PR c++/103105

    gcc/cp/ChangeLog:

            * pt.c (build_extra_args): Call preserve_args.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-requires29.C: New test.
            * g++.dg/cpp2a/concepts-requires29a.C: New test.

    (cherry picked from commit e2c7070ac7740508a7c49bfee9f895e216a272d6)

[Bug c++/103105] [11 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105
Bug 103105 depends on bug 103706, which changed state.

Bug 103706 Summary: [11 Regression] ICE: tree check: accessed elt 1 of 'tree_vec' with 0 elts in hash, at cp/constraint.cc:2503
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103706

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

[Bug c++/103105] [11 Regression] ICE iterative_hash_template_arg with concepts and varagrs template since r11-3261-gb28b621ac67beee8

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103105

Patrick Palka <ppalka at gcc dot gnu.org> changed:

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

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 11.3/12.