[Bug c++/107267] New: ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[Bug c++/107267] New: ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

            Bug ID: 107267
           Summary: ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253
           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 53705
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53705&action=edit
gzipped C++ source code

The attached C++ code, with compiler flag -O1, does this with recent gcc:

/home/dcb36/rpmbuild/BUILD/Vulkan-ValidationLayers-sdk-1.2.198.0/layers/vk_layer_utils.h:428:18:
internal compil
er error: in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253
  428 |             auto ret = std::move(FindResult(true, itr->second));
      |                  ^~~
0x76bbbd cp_gimplify_init_expr(tree_node**)
        ../../trunk.git/gcc/cp/cp-gimplify.cc:253
0x76bbbd cp_gimplify_expr(tree_node**, gimple**, gimple**)
        ../../trunk.git/gcc/cp/cp-gimplify.cc:508

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #1 from David Binderman <dcb314 at hotmail dot com> ---
The compiler first seems to break sometime between git hash 8a9e92b249c9c5a5
and 6ffbf87ca66f4ed9, a day later.

Reduction running.

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #2 from David Binderman <dcb314 at hotmail dot com> ---
There is only one mention of cp_gimplify_init_expr in that git
range, and it is the final commit of Jason's, marked
6ffbf87ca66f4ed9cd79cff675fabe2109e46e85.

Not a smoking gun, but possibly a lead candidate.

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #3 from David Binderman <dcb314 at hotmail dot com> ---
Reduced C++ code is

template <int __v> struct integral_constant {
  static constexpr int value = __v;
};
template <bool __v> using __bool_constant = integral_constant<__v>;
template <int> struct __conditional {
  template <typename _Tp, typename> using type = _Tp;
};
template <bool _Cond, typename _If, typename _Else>
using __conditional_t = typename __conditional<_Cond>::type<_If, _Else>;
template <typename _Tp> struct remove_reference { using type = _Tp; };
namespace std {
template <typename _Tp> typename remove_reference<_Tp>::type &&move(_Tp &&);
struct pair {
  int second;
};
template <int _Constant_iterators> struct _Hashtable_traits {
  using __constant_iterators = __bool_constant<_Constant_iterators>;
};
template <int __constant_iterators> struct _Node_iterator {
  using value_type = pair;
  using pointer =
      __conditional_t<__constant_iterators, value_type *, value_type>;
  pointer operator->();
};
struct _Insert_base {
  using __constant_iterators = _Hashtable_traits<false>::__constant_iterators;
  using iterator = _Node_iterator<__constant_iterators::value>;
};
template <typename, typename> using __umap_hashtable = _Insert_base;
struct unordered_map {
  __umap_hashtable<int, int>::iterator find(int);
};
} // namespace std
template <typename, typename> using unordered_map = std::unordered_map;
struct vl_concurrent_unordered_map {
  struct FindResult {
    FindResult(bool, int);
    std::pair result;
  };
  int pop_key;
  void pop() {
    auto itr = maps[0].find(pop_key);
    auto ret = std::move(FindResult(true, itr->second));
  }
  unordered_map<int, int> maps[];
} unique_id_mapping;
void DispatchDestroyAccelerationStructureKHR() { unique_id_mapping.pop(); }

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #4 from David Binderman <dcb314 at hotmail dot com> ---
Trying a git bisect with git hash 93b3ab6c0c6a44df.

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #5 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to David Binderman from comment #4)
> Trying a git bisect with git hash 93b3ab6c0c6a44df.

Seems good. Trying eb491ea5c10955c6.

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #6 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to David Binderman from comment #5)
> (In reply to David Binderman from comment #4)
> > Trying a git bisect with git hash 93b3ab6c0c6a44df.
> 
> Seems good. Trying eb491ea5c10955c6.

Seems good. Trying b9ad850e86b863c2.

[Bug c++/107267] ice in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

David Binderman <dcb314 at hotmail dot com> changed:

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

--- Comment #7 from David Binderman <dcb314 at hotmail dot com> ---
Advice of Jason sought.

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2022-10-17
            Summary|ice in                      |[13 Regression] ICE in
                   |cp_gimplify_init_expr, at   |cp_gimplify_init_expr, at
                   |cp/cp-gimplify.cc:253       |cp/cp-gimplify.cc:253 since
                   |                            |r13-3175-g6ffbf87ca66f4ed9
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |marxin at gcc dot gnu.org
           Keywords|ice-on-valid-code,          |rejects-valid
                   |needs-bisection             |

--- Comment #8 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r13-3175-g6ffbf87ca66f4ed9.

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #9 from Martin Liška <marxin at gcc dot gnu.org> ---
More reduced test-case:

template <int __v> struct integral_constant {
  static constexpr int value = __v;
};
template <bool __v> using __bool_constant = integral_constant<__v>;
template <int> struct __conditional {
  template <typename _Tp, typename> using type = _Tp;
};
template <bool _Cond, typename _If, typename _Else>
using __conditional_t = typename __conditional<_Cond>::type<_If, _Else>;
namespace std {
template <typename _Tp> _Tp &&move(_Tp &&);
struct pair {
  int second;
};
template <int _Constant_iterators> struct _Hashtable_traits {
  using __constant_iterators = __bool_constant<_Constant_iterators>;
};
template <int __constant_iterators> struct _Node_iterator {
  __conditional_t<__constant_iterators, pair *, pair> operator->();
};
using iterator =
    _Node_iterator<_Hashtable_traits<false>::__constant_iterators::value>;
} // namespace std
struct FindResult {
  FindResult(bool, int);
  std::pair result;
};
std::iterator pop_itr;
FindResult pop_ret = std::move(FindResult(true, pop_itr->second));

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1
            Version|12.0                        |13.0

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[dcb314 at hotmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #10 from David Binderman <dcb314 at hotmail dot com> ---
(In reply to Martin Liška from comment #8)
> Started with r13-3175-g6ffbf87ca66f4ed9.

So maybe it would be a good idea to assign this bug to Jason ?

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

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

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

--- Comment #11 from Patrick Palka <ppalka at gcc dot gnu.org> ---
FWIW -ffold-simple-inline is sufficient to trigger the ICE, so this has
something to do with cp_fold's folding of std::move.  More reduced:

$ cat 107267.C
namespace std {
  template<typename _Tp> _Tp &&move(_Tp &&);
}

struct FindResult {
  FindResult();
  int result;
};

FindResult pop_ret = std::move(FindResult());

$ g++ -ffold-simple-inlines 107267.C
107267.C:10:44: internal compiler error: in cp_gimplify_init_expr, at
cp/cp-gimplify.cc:253
   10 | FindResult pop_ret = std::move(FindResult());
      |                                            ^

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

Jason Merrill <jason at gcc dot gnu.org> changed:

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

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

--- Comment #12 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The trunk branch has been updated by Jason Merrill <jason@gcc.gnu.org>:

https://gcc.gnu.org/g:4cbc71691e47b1ca6b64feb0af678606705d2f92

commit r13-5316-g4cbc71691e47b1ca6b64feb0af678606705d2f92
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Jan 23 17:14:11 2023 -0500

    c++: TARGET_EXPR_ELIDING_P and std::move [PR107267]

    With -ffold-simple-inlines, we turn calls to std::move into the static_cast
    equivalent.  In this testcase, this exposes the FindResult temporary to
copy
    elision which is not specified by the standard, through an optimization in
    gimplify_modify_expr_rhs.  Since the type is not TREE_ADDRESSABLE, this is
    not detectable by the user, so we just need to soften the assert.

            PR c++/107267

    gcc/cp/ChangeLog:

            * cp-gimplify.cc (cp_gimplify_init_expr): Allow unexpected elision
            of trivial types.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp0x/move2.C: New test.

[Bug c++/107267] [13 Regression] ICE in cp_gimplify_init_expr, at cp/cp-gimplify.cc:253 since r13-3175-g6ffbf87ca66f4ed9

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107267

Jason Merrill <jason at gcc dot gnu.org> changed:

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

--- Comment #13 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed.