[Bug c++/95317] New: [7 regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[Bug c++/95317] New: [7 regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[fxcoudert at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

            Bug ID: 95317
           Summary: [7 regression] ICE on valid C++14 code, in
                    tsubst_copy, at cp/pt.c:15649
           Product: gcc
           Version: 9.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: fxcoudert at gcc dot gnu.org
  Target Milestone: ---

ICE on valid C++14 code:

$ cat b.C
#include <iostream>

template <int I>
struct num
{
    enum { value = I };
};

#define VALUEOFNUM(x) std::remove_reference_t<decltype(x)>::value


template <typename TYPE>
void foo()
{
    auto test = [&](auto i)
    {
        enum { VALUE = VALUEOFNUM(i) };
        std::cout << VALUE;
    };

    test(num<0>());
    test(num<1>());
}

int main()
{
    foo<void>();
}

$ g++-9 b.C 
b.C: In instantiation of 'void foo() [with TYPE = void]':
b.C:27:15:   required from here
b.C:18:22: internal compiler error: in tsubst_copy, at cp/pt.c:15649
   18 |         std::cout << VALUE;
      |                      ^~~~~
libbacktrace could not find executable to open
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://github.com/Homebrew/homebrew-core/issues> for instructions.



Works fine with GCC up to version 6, but regresses at 7 and later.

[Bug c++/95317] [8/9/10/11 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
   Target Milestone|---                         |8.5
      Known to work|                            |6.5.0
            Summary|[7 regression] ICE on valid |[8/9/10/11 Regression] ICE
                   |C++14 code, in tsubst_copy, |on valid C++14 code, in
                   |at cp/pt.c:15649            |tsubst_copy, at
                   |                            |cp/pt.c:15649

[Bug c++/95317] [8/9/10/11 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2020-05-26
     Ever confirmed|0                           |1

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Confirmed, started with r8-2720-gf44a8dd56f5bfbd0.

[Bug c++/95317] [8/9/10/11 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Reduced test-case:

cat pr95317.ii
template <typename> void fn1() {
  [](auto) {
    enum { VALUE };
    VALUE;
  };
}
main() { fn1<void>; }

[Bug c++/95317] [8/9/10/11 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

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

[Bug c++/95317] [8/9/10/11 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

https://gcc.gnu.org/g:9f4c41147a41d08a74990eafe69a1064a3c13435

commit r11-7993-g9f4c41147a41d08a74990eafe69a1064a3c13435
Author: Jason Merrill <jason@redhat.com>
Date:   Mon Apr 5 14:26:03 2021 -0400

    c++: enum in generic lambda in template [PR95317]

    Here we weren't instantiating the enumerators because the arglist still had
    the template parameter for the generic lambda, so looking one up failed. 
We
    need to instantiate if the non-lambda enclosing scope is non-dependent.

    gcc/cp/ChangeLog:

            PR c++/95317
            * pt.c (lookup_template_class_1): Do tsubst_enum when
            tsubsting a generic lambda.

    gcc/testsuite/ChangeLog:

            PR c++/95317
            * g++.dg/cpp1y/lambda-generic-enum1.C: New test.

[Bug c++/95317] [8/9/10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |11.0
            Summary|[8/9/10/11 Regression] ICE  |[8/9/10 Regression] ICE on
                   |on valid C++14 code, in     |valid C++14 code, in
                   |tsubst_copy, at             |tsubst_copy, at
                   |cp/pt.c:15649               |cp/pt.c:15649
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jason at gcc dot gnu.org

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 11 so far.

[Bug c++/95317] [8/9/10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |zchendd at connect dot ust.hk

--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
*** Bug 100271 has been marked as a duplicate of this bug. ***

[Bug c++/95317] [9/10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|8.5                         |9.4

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 8 branch is being closed.

[Bug c++/95317] [9/10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.4                         |9.5

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9.4 is being released, retargeting bugs to GCC 9.5.

[Bug c++/95317] [9/10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |tim at ngus dot net

--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 101343 has been marked as a duplicate of this bug. ***

[Bug c++/95317] [10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|9.5                         |10.4

--- Comment #9 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 9 branch is being closed

[Bug c++/95317] [10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.4                        |10.5

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 10.4 is being released, retargeting bugs to GCC 10.5.

[Bug c++/95317] [10 Regression] ICE on valid C++14 code, in tsubst_copy, at cp/pt.c:15649

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95317

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.5                        |11.0
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
      Known to fail|                            |10.5.0

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed for GCC 11.