[Bug c++/111471] New: Incorrect NTTP printing in the error messages

[Bug c++/111471] New: Incorrect NTTP printing in the error messages

[mateusz.pusz at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111471

            Bug ID: 111471
           Summary: Incorrect NTTP printing in the error messages
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mateusz.pusz at gmail dot com
  Target Milestone: ---

Please see the following example https://godbolt.org/z/qajTKdnGq:

There are many similar issues:

```
required for the satisfaction of 'ReferenceOf<typename
std::remove_const<decltype (Q::reference)>::type, V>' [with Q =
mp_units::quantity<{}, double>; V = _ZTAXtlN8mp_units3isq5speedEEE]
```

The `{}` part above does not help at all and should print the actual type of
the NTTP somewhere. `_ZTAXtlN8mp_units3isq5speedEEE` should be properly
demangled. 

```
note: the expression 'implicitly_convertible({}, QS) [with T =
mp_units::kind_of_<{}>; QS = _ZTAXtlN8mp_units3isq5speedEEE]' evaluated to
'false'
```

Again, lack of demangling and mysterious `{}`.

[Bug c++/111471] Incorrect NTTP printing in the error messages

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111471

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.3
           Keywords|                            |diagnostic
   Last reconfirmed|                            |2023-09-19
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
             Status|UNCONFIRMED                 |ASSIGNED
     Ever confirmed|0                           |1
                 CC|                            |ppalka at gcc dot gnu.org

--- Comment #1 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Confirmed.

[Bug c++/111471] Incorrect NTTP printing in the error messages

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111471

--- 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:75c4b0cde4835b45350da0a5cd82f1d1a0a7a2f1

commit r14-4178-g75c4b0cde4835b45350da0a5cd82f1d1a0a7a2f1
Author: Patrick Palka <ppalka@redhat.com>
Date:   Wed Sep 20 12:09:36 2023 -0400

    c++: improve class NTTP object pretty printing [PR111471]

    1. Move class NTTP object pretty printing to a more general spot in
       the pretty printer, so that we always print its value instead of
       its (mangled) name even when it appears outside of a template
       argument list.
    2. Print the type of an class NTTP object alongside its CONSTRUCTOR
       value, like dump_expr would have done.
    3. Don't print const VIEW_CONVERT_EXPR wrappers for class NTTPs.

            PR c++/111471

    gcc/cp/ChangeLog:

            * cxx-pretty-print.cc (cxx_pretty_printer::expression)
            <case VAR_DECL>: Handle class NTTP objects by printing
            their type and value.
            <case VIEW_CONVERT_EXPR>: Strip const VIEW_CONVERT_EXPR
            wrappers for class NTTPs.
            (pp_cxx_template_argument_list): Don't handle class NTTP
            objects here.

    gcc/testsuite/ChangeLog:

            * g++.dg/concepts/diagnostic19.C: New test.

[Bug c++/111471] Incorrect NTTP printing in the error messages

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111471

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-13 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:b7d2bb488efbdeab42cf047d92cf0f9acdc1c5ec

commit r13-7830-gb7d2bb488efbdeab42cf047d92cf0f9acdc1c5ec
Author: Patrick Palka <ppalka@redhat.com>
Date:   Wed Sep 20 12:09:36 2023 -0400

    c++: improve class NTTP object pretty printing [PR111471]

    1. Move class NTTP object pretty printing to a more general spot in
       the pretty printer, so that we always print its value instead of
       its (mangled) name even when it appears outside of a template
       argument list.
    2. Print the type of an class NTTP object alongside its CONSTRUCTOR
       value, like dump_expr would have done.
    3. Don't print const VIEW_CONVERT_EXPR wrappers for class NTTPs.

            PR c++/111471

    gcc/cp/ChangeLog:

            * cxx-pretty-print.cc (cxx_pretty_printer::expression)
            <case VAR_DECL>: Handle class NTTP objects by printing
            their type and value.
            <case VIEW_CONVERT_EXPR>: Strip const VIEW_CONVERT_EXPR
            wrappers for class NTTPs.
            (pp_cxx_template_argument_list): Don't handle class NTTP
            objects here.

    gcc/testsuite/ChangeLog:

            * g++.dg/concepts/diagnostic19.C: New test.

    (cherry picked from commit 75c4b0cde4835b45350da0a5cd82f1d1a0a7a2f1)

[Bug c++/111471] Incorrect NTTP printing in the error messages

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111471

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|13.3                        |13.4

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 13.3 is being released, retargeting bugs to GCC 13.4.