[Bug c++/107464] New: Expression error in qualified name lookup with lambdas in unevaluated context

[Bug c++/107464] New: Expression error in qualified name lookup with lambdas in unevaluated context

[roma.sandu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107464

            Bug ID: 107464
           Summary: Expression error in qualified name lookup with lambdas
                    in unevaluated context
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: roma.sandu at gmail dot com
  Target Milestone: ---

Created attachment 53795
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53795&action=edit
Minimal bug repro

I've discovered an interesting bug with unevaluated context lambdas. In the
attached examples, trying to instantiate `boo` with a qualified name results in
an expression error. If we instead bring the name `spooky::boo` into the `evil`
namespace with a `using` statement and instantiate `boo` through an unqualified
name, it works as expected. And finally, if one removes the unevaluated context
lambda in `boo`'s definition, it works in all cases.

[Bug c++/107464] Expression error in qualified name lookup with lambdas in unevaluated context

[roma.sandu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107464

--- Comment #1 from Роман Санду <roma.sandu at gmail dot com> ---
Created attachment 53796
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53796&action=edit
No bug with unqualified name

[Bug c++/107464] Expression error in qualified name lookup with lambdas in unevaluated context

[roma.sandu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107464

--- Comment #2 from Роман Санду <roma.sandu at gmail dot com> ---
Here's a link to godbolt with the minimal reproducing test case:
https://godbolt.org/z/5PoYd3sPs

Note that the bug is present in both gcc trunk and gcc 12.2.

[Bug c++/107464] Expression error in qualified name lookup with lambdas in unevaluated context

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107464

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
There are definitely issues with lamdba in decltype and aliases and this is
just one of many.

[Bug c++/107464] Expression error in qualified name lookup with lambdas in unevaluated context

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107464

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |14.0
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Fixed on the trunk for GCC 14 by the recent lambda template patches.