[Bug c++/105304] New: ICE segfault using ad-hoc concept with -Wall

[Bug c++/105304] New: ICE segfault using ad-hoc concept with -Wall

[bjoern at hoehrmann dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

            Bug ID: 105304
           Summary: ICE segfault using ad-hoc concept with -Wall
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bjoern at hoehrmann dot de
  Target Milestone: ---

GCC 11.2.0 on Linux

 ❯  g++-11 -Wall -std=c++2a -o x ../mini.cxx   
../mini.cxx: In function 'int main()':
../mini.cxx:23:18: internal compiler error: Segmentation fault
   23 |                 }) {
      |                  ^
Please submit a full bug report,

Code:

#include <iostream>
#include <utility>

class X
{
public:
  int m(int, int, int = 7) { return 123; }
};

template<typename... Ts>
void
invoke_m(std::index_sequence_for<Ts...> is)
{
  X o;
  o.m(Ts()...);
}

int
main()
{
  if constexpr (requires {
                  invoke_m<int, int, int, int>(std::make_index_sequence<4>());
                }) {
    std::cerr << "ok" << '\n';
  }

  return 0;
}

Compiles when omitting -Wall.

[Bug c++/105304] [10/11/12 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |ppalka at gcc dot gnu.org
            Summary|ICE segfault using ad-hoc   |[10/11/12 Regression] ICE
                   |concept with -Wall          |segfault using ad-hoc
                   |                            |concept with -Wall since
                   |                            |r10-7441-ga7ea3d2ced786c45
   Last reconfirmed|                            |2022-04-19

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r10-7441-ga7ea3d2ced786c45.

[Bug c++/105304] [10/11/12 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
   Target Milestone|---                         |10.4

[Bug c++/105304] [10/11/12 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

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++/105304] [10/11/12 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

--- Comment #2 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:c83b9c54d9dee2dce5d8268472a745b013d166cc

commit r12-8257-gc83b9c54d9dee2dce5d8268472a745b013d166cc
Author: Patrick Palka <ppalka@redhat.com>
Date:   Mon Apr 25 21:49:00 2022 -0400

    c++: ICE with requires-expr and -Wsequence-point [PR105304]

    Here we're crashing from verify_sequence_points for this requires-expr
    condition because it contains a templated CAST_EXPR with empty operand,
    and verify_tree doesn't ignore this empty operand only because the
    manual tail recursion that it performs for unary expression trees skips
    the NULL test.

            PR c++/105304

    gcc/c-family/ChangeLog:

            * c-common.cc (verify_tree) [restart]: Move up to before the
            NULL test.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-requires30.C: New test.

[Bug c++/105304] [10/11 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[10/11/12 Regression] ICE   |[10/11 Regression] ICE
                   |segfault using ad-hoc       |segfault using ad-hoc
                   |concept with -Wall since    |concept with -Wall since
                   |r10-7441-ga7ea3d2ced786c45  |r10-7441-ga7ea3d2ced786c45

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 12 so far.

[Bug c++/105304] [10/11 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

--- Comment #4 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:992dd9a071c16b94a616ab7242390b6581fa6001

commit r11-9946-g992dd9a071c16b94a616ab7242390b6581fa6001
Author: Patrick Palka <ppalka@redhat.com>
Date:   Mon Apr 25 21:49:00 2022 -0400

    c++: ICE with requires-expr and -Wsequence-point [PR105304]

    Here we're crashing from verify_sequence_points for this requires-expr
    condition because it contains a templated CAST_EXPR with empty operand,
    and verify_tree doesn't ignore this empty operand only because the
    manual tail recursion that it performs for unary expression trees skips
    the NULL test.

            PR c++/105304

    gcc/c-family/ChangeLog:

            * c-common.c (verify_tree) [restart]: Move up to before the
            NULL test.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-requires30.C: New test.

    (cherry picked from commit c83b9c54d9dee2dce5d8268472a745b013d166cc)

[Bug c++/105304] [10 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:9a8b7edbe65ec6350a996eab51a7c26a087e6d2b

commit r10-10605-g9a8b7edbe65ec6350a996eab51a7c26a087e6d2b
Author: Patrick Palka <ppalka@redhat.com>
Date:   Mon Apr 25 21:49:00 2022 -0400

    c++: ICE with requires-expr and -Wsequence-point [PR105304]

    Here we're crashing from verify_sequence_points for this requires-expr
    condition because it contains a templated CAST_EXPR with empty operand,
    and verify_tree doesn't ignore this empty operand only because the
    manual tail recursion that it performs for unary expression trees skips
    the NULL test.

            PR c++/105304

    gcc/c-family/ChangeLog:

            * c-common.c (verify_tree) [restart]: Move up to before the
            NULL test.

    gcc/testsuite/ChangeLog:

            * g++.dg/cpp2a/concepts-requires30.C: New test.

    (cherry picked from commit c83b9c54d9dee2dce5d8268472a745b013d166cc)

[Bug c++/105304] [10 Regression] ICE segfault using ad-hoc concept with -Wall since r10-7441-ga7ea3d2ced786c45

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105304

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 10.4/11.4/12, thanks for the bug report.