[Bug ada/82529] New: Warning on unreferenced "with" is not produced

[porton at narod dot ru]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82529

            Bug ID: 82529
           Summary: Warning on unreferenced "with" is not produced
           Product: gcc
           Version: 7.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: porton at narod dot ru
  Target Milestone: ---

Created attachment 42345
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=42345&action=edit
The compilation units which should produce a warning

The command "gcc-7 -c -gnat12 -gnatwa test.adb" does not produce a warning on
unreferenced "with Ada.Unchecked_Conversion", despite it must produce such
warning.

The full program text is attached in all.chop and also reprised here.

with Ada.Unchecked_Conversion;
with Ada.Text_IO;
with X;

procedure Test is
begin
  Ada.Text_IO.Put_Line(Integer'Image(X.C(0)));
end;

with Ada.Unchecked_Conversion;

package X is
  function C is new Ada.Unchecked_Conversion(Integer, integer);
end X;