[Bug c++/104836] New: ice in unify, at cp/pt.cc:24055

[Bug c++/104836] New: ice in unify, at cp/pt.cc:24055

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104836

            Bug ID: 104836
           Summary: ice in unify, at cp/pt.cc:24055
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 52580
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52580&action=edit
C++ source code

For the attached C++ code, recent gcc trunk does this:

bug796.cc: In substitution of ‘template<Ts ...Ns, int (* ...Ps)[3]> A<int [3],
i
nt, int, short int>::A(X<Ps ...>, Ts (*)[Ns]...) [with Ts ...Ns = <missing>;
int
 (* ...Ps)[3] = {(& arr1), (& arr2)}]’:
bug796.cc:12:43:   required from here
bug796.cc:12:43: internal compiler error: in unify, at cp/pt.cc:24055
   12 | A a(X<&arr1, &arr2>{}, &arr1, &arr2, &arr3);
      |                                           ^
0x9432e3 unify(tree_node*, tree_node*, tree_node*, tree_node*, int, bool)
        ../../trunk.git/gcc/cp/pt.cc:24055

This code is a copy of a file from the clang test suite, file 
SemaTemplate/deduction-guide.cpp.

[Bug c++/104836] ice in unify, at cp/pt.cc:24055

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104836

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

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

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with -std=c++17 with r7-4431-g4a826ca6feb3c7ec.

[Bug c++/104836] ice in unify, at cp/pt.cc:24055

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104836

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
           Keywords|                            |ice-on-valid-code
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2022-03-09

[Bug c++/104836] ice in unify, at cp/pt.cc:24055

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104836

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

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

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
// PR c++/104836

template<auto ...> struct X {};
template<template<typename X, X> typename> struct Y {};
template<typename ...> struct Z {};

template<typename T, typename ...Ts> struct A {
  template<Ts ...Ns, T *...Ps> A(X<Ps...>, Ts (*...qs)[Ns]);
};
int arr1[3], arr2[3];
short arr3[4];
A a(X<&arr1, &arr2>{}, &arr1, &arr2, &arr3);
using AT = decltype(a);
using AT = A<int[3], int, int, short>;