[Bug c++/95371] New: [10 Regression] ICE concepts with template template parameter

[Bug c++/95371] New: [10 Regression] ICE concepts with template template parameter

[gcc-bugs at marehr dot dialup.fu-berlin.de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

            Bug ID: 95371
           Summary: [10 Regression] ICE concepts with template template
                    parameter
           Product: gcc
           Version: 10.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: gcc-bugs at marehr dot dialup.fu-berlin.de
  Target Milestone: ---

Hallo gcc-team,

the following code worked with gcc9, but ICEs with gcc 10.1 and in trunk

```c++
template <typename...>
struct configuration  {
    template <template <typename...> typename query_t>
    static constexpr bool exists() { return true; }

    template <template <typename...> typename query_t>
    void remove() requires(exists<query_t>());
};

int main() {
    configuration<> cfg{};
    cfg.remove<configuration>();
}
```

https://godbolt.org/z/NGU5i9


```
> g++-10 -std=c++2a
<source>: In function 'int main()':
<source>:12:31: internal compiler error: Segmentation fault
   12 |     cfg.remove<configuration>();
      |                               ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <https://gcc.gnu.org/bugs/> for instructions.
Compiler returned: 1
```

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[10 Regression] ICE         |[10/11 Regression] ICE
                   |concepts with template      |concepts with template
                   |template parameter          |template parameter since
                   |                            |r10-3735-gcb57504a55015891
   Last reconfirmed|                            |2020-05-27
           Keywords|                            |needs-reduction
             Status|UNCONFIRMED                 |NEW
                 CC|                            |jason at gcc dot gnu.org,
                   |                            |marxin at gcc dot gnu.org
     Ever confirmed|0                           |1

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|needs-reduction             |ice-on-valid-code

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Whoops, it's already reduced.

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |10.2

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

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++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

--- Comment #2 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:2fb595f8348e164d2f06536ba98322616eeaeeb6

commit r11-734-g2fb595f8348e164d2f06536ba98322616eeaeeb6
Author: Jason Merrill <jason@redhat.com>
Date:   Fri May 29 16:55:52 2020 -0400

    c++: Template template parameter in constraint [PR95371]

    any_template_parm_r was assuming that the DECL_TEMPLATE_RESULT of a
template
    will have a suitable TEMPLATE_INFO from which we can look at the generic
    arguments for that template.  But that wasn't true for a template template
    parameter; this patch makes it so.

    gcc/cp/ChangeLog:

            PR c++/95371
            * pt.c (process_template_parm): Set DECL_TEMPLATE_INFO
            on the DECL_TEMPLATE_RESULT.

    gcc/testsuite/ChangeLog:

            PR c++/95371
            * g++.dg/cpp2a/concepts-ttp1.C: New test.

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jason Merrill
<jason@gcc.gnu.org>:

https://gcc.gnu.org/g:c07c745b1ef62f633024824b7e125027f10c969b

commit r10-8211-gc07c745b1ef62f633024824b7e125027f10c969b
Author: Jason Merrill <jason@redhat.com>
Date:   Fri May 29 16:55:52 2020 -0400

    c++: Template template parameter in constraint [PR95371]

    gcc/cp/ChangeLog:

            PR c++/95371
            * pt.c (process_template_parm): Set DECL_TEMPLATE_INFO
            on the DECL_TEMPLATE_RESULT.

    gcc/testsuite/ChangeLog:

            PR c++/95371
            * g++.dg/cpp2a/concepts-ttp1.C: New test.

    (cherry picked from commit d91b3aea7a5bdfbdaec746af2d62894812e6fd86)

[Bug c++/95371] [10/11 Regression] ICE concepts with template template parameter since r10-3735-gcb57504a55015891

[jason at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95371

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

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

--- Comment #4 from Jason Merrill <jason at gcc dot gnu.org> ---
Fixed for 10.2/11.