[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=83258

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The first example works with -std=c++20 as expected (it is not valid C++17 and
gets rejected with -std=c++1z too).

The second example is related to PR 83258 (or is a dup of that bug).

[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80488

--- Comment #3 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:c3afdb8ba8f1839544c414f57e41a58c8fda5349

commit r14-708-gc3afdb8ba8f1839544c414f57e41a58c8fda5349
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu May 11 10:04:25 2023 -0400

    c++: converted lambda as template argument [PR83258, ...]

    r8-1253-g3d2e25a240c711 removed the template argument linkage requirement
    in convert_nontype_argument for C++17 (which r9-3836-g4be5c72cf3ea3e later
    factored out into invalid_tparm_referent_p), but we need to also remove
    the one in convert_nontype_argument_function for benefit of the first and
    third testcase which we currently reject even in C++17/20 mode.

    And in invalid_tparm_referent_p we're inadvertendly returning false for
    the address of a lambda's static op() since it's DECL_ARTIFICIAL, which
    currently causes us to reject the second (C++20) testcase.  But this
    DECL_ARTIFICIAL check seems to be relevant only for VAR_DECL, and in fact
    this code path was originally reachable only for VAR_DECL until recently
    (r13-6970-gb5e38b1c166357).  So this patch restricts the check to VAR_DECL.

    Co-authored-by: Jonathan Wakely <jwakely@redhat.com>

            PR c++/83258
            PR c++/80488
            PR c++/97700

    gcc/cp/ChangeLog:

            * pt.cc (convert_nontype_argument_function): Remove linkage
            requirement for C++17 and later.
            (invalid_tparm_referent_p) <case ADDR_EXPR>: Restrict
            DECL_ARTIFICIAL rejection test to VAR_DECL.

    gcc/testsuite/ChangeLog:

            * g++.dg/ext/visibility/anon8.C: Don't expect a "no linkage"
            error for the template argument &B2:fn in C++17 mode.
            * g++.dg/cpp0x/lambda/lambda-conv15.C: New test.
            * g++.dg/cpp2a/nontype-class56.C: New test.
            * g++.dg/template/function2.C: New test.

[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80488

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
                 CC|                            |ppalka at gcc dot gnu.org
   Target Milestone|---                         |13.2

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed on trunk so far.

[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80488

--- Comment #5 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:42f9b481be3527b336b800128247d053fd18d121

commit r13-7324-g42f9b481be3527b336b800128247d053fd18d121
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu May 11 10:04:25 2023 -0400

    c++: converted lambda as template argument [PR83258, ...]

    r8-1253-g3d2e25a240c711 removed the template argument linkage requirement
    in convert_nontype_argument for C++17 (which r9-3836-g4be5c72cf3ea3e later
    factored out into invalid_tparm_referent_p), but we need to also remove
    the one in convert_nontype_argument_function for benefit of the first and
    third testcase which we currently reject even in C++17/20 mode.

    And in invalid_tparm_referent_p we're inadvertendly returning false for
    the address of a lambda's static op() since it's DECL_ARTIFICIAL, which
    currently causes us to reject the second (C++20) testcase.  But this
    DECL_ARTIFICIAL check seems to be relevant only for VAR_DECL, and in fact
    this code path was originally reachable only for VAR_DECL until recently
    (r13-6970-gb5e38b1c166357).  So this patch restricts the check to VAR_DECL.

    Co-authored-by: Jonathan Wakely <jwakely@redhat.com>

            PR c++/83258
            PR c++/80488
            PR c++/97700

    gcc/cp/ChangeLog:

            * pt.cc (convert_nontype_argument_function): Remove linkage
            requirement for C++17 and later.
            (invalid_tparm_referent_p) <case ADDR_EXPR>: Restrict
            DECL_ARTIFICIAL rejection test to VAR_DECL.

    gcc/testsuite/ChangeLog:

            * g++.dg/ext/visibility/anon8.C: Don't expect a "no linkage"
            error for the template argument &B2:fn in C++17 mode.
            * g++.dg/cpp0x/lambda/lambda-conv15.C: New test.
            * g++.dg/cpp2a/nontype-class56.C: New test.
            * g++.dg/template/function2.C: New test.

    (cherry picked from commit c3afdb8ba8f1839544c414f57e41a58c8fda5349)

[Bug c++/80488] Erroneous error "lambda-expression in template argument"

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80488

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

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

--- Comment #6 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Should be fully fixed for GCC 13.2