[Bug c++/102576] New: [modules] Importing <initializer_list> doesn't permit implicit uses

[Bug c++/102576] New: [modules] Importing <initializer_list> doesn't permit implicit uses

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102576

            Bug ID: 102576
           Summary: [modules] Importing <initializer_list> doesn't permit
                    implicit uses
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: johelegp at gmail dot com
                CC: johelegp at gmail dot com
  Target Milestone: ---

A use like

```C++
import<initializer_list>;

constexpr void test() {
  for (const int i : {0, 1, -1}) { }
}
```

results in an error like

```
error: deducing from brace-enclosed initializer list requires ‘#include
<initializer_list>’
    3 | import<initializer_list>;
  +++ |+#include <initializer_list>
    4 | // import<iterator>;
......
   11 |   for (const int i : {0, 1, -1}) {
      |                               ^
```

[Bug c++/102576] [modules] Importing <initializer_list> doesn't permit implicit uses

[johelegp at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102576

--- Comment #1 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
`<array>` is specified as including `<initializer_list>`.
It doesn't with with that either:

```C++
import<array>;

namespace {

constexpr void test() {
  for (const int i : {0, 1, -1}) { }
```

```
error: deducing from brace-enclosed initializer list requires ‘#include
<initializer_list>’
    2 | import<array>;
  +++ |+#include <initializer_list>
    3 | // import<iterator>;
......
   10 |   for (const int i : {0, 1, -1}) {
      |                               ^
```

This might apply more generally to standard headers specified as including
other headers.

[Bug c++/102576] [modules] Importing <initializer_list> doesn't permit implicit uses

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102576

--- 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:c2ee70f20de8133a88553270073226b0f3f55f62

commit r13-2969-gc2ee70f20de8133a88553270073226b0f3f55f62
Author: Patrick Palka <ppalka@redhat.com>
Date:   Thu Sep 29 16:27:30 2022 -0400

    c++: implicit lookup of std::initializer_list [PR102576]

    Here the lookup for the implicit use of std::initializer_list fails
    because we do it using get_namespace_binding, which isn't import aware.
    Fix this by using lookup_qualified_name instead.

            PR c++/102576

    gcc/cp/ChangeLog:

            * pt.cc (listify): Use lookup_qualified_name instead of
            get_namespace_binding.

    gcc/testsuite/ChangeLog:

            * g++.dg/modules/pr102576_a.H: New test.
            * g++.dg/modules/pr102576_b.C: New test.

[Bug c++/102576] [modules] Importing <initializer_list> doesn't permit implicit uses

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102576

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
           Assignee|unassigned at gcc dot gnu.org      |ppalka at gcc dot gnu.org
             Status|UNCONFIRMED                 |RESOLVED
                 CC|                            |ppalka at gcc dot gnu.org
   Target Milestone|---                         |13.0

--- Comment #3 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Fixed for GCC 13

[Bug c++/102576] [modules] Importing <initializer_list> doesn't permit implicit uses

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102576

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |matthewsatti at gmail dot com

--- Comment #4 from Patrick Palka <ppalka at gcc dot gnu.org> ---
*** Bug 109295 has been marked as a duplicate of this bug. ***