[Bug ada/85760] New: Using generic function to initialize a type created by a generic package crashes GNAT

[jhb.chat at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85760

            Bug ID: 85760
           Summary: Using generic function to initialize a type created by
                    a generic package crashes GNAT
           Product: gcc
           Version: 7.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jhb.chat at gmail dot com
  Target Milestone: ---
              Host: Windows 10 msys2 mingw64
            Target: x86_64-w64-mingw32

given a package, 

Wrappers.ads
************************************************
generic
   type Element_Type is limited private;
package Wrappers is

   type Wrapper is tagged limited private;

   -- Causes GNAT crash when used to initialize a wrapper
   -- Happens in GNAT GPL 2017, FSF GNAT 7.2, and FSF GNAT 7.3
   generic
      with function Constructor(Value : Element_Type) return Element_Type;
   function Make(Value : Element_Type) return Wrapper;

private

   type Wrapper is tagged limited null record;

end Wrappers;
************************************************

wrappers.adb
************************************************
package body Wrappers is

   function Make(Value : Element_Type) return Wrapper is
   begin
      return (others => <>);
   end Make;

end Wrappers;
************************************************

implemented in main.adb
************************************************
with Ada.Text_IO; use Ada.Text_IO;
with Wrappers;

procedure Main is
   package Int_Wrappers is new Wrappers(Integer);

   function Make(Value : Integer) return Integer is (Value);
   function Make is new Int_Wrappers.Make
      (Constructor => Make);

   v : Int_Wrappers.Wrapper := Make(50);
begin
  null;
end Main;
************************************************

outputs:
************************************************
$ gprbuild default.gpr
gcc -c -g -gnatn -gnato -gnatE -fstack-check -gnat12 -O3 -g main.adb
gprbuild: *** compilation phase failed
************************************************

Side Note:  Compiling in GNAT GPL 2017 outputs:
************************************************
Compile
   [Ada]          main.adb
+===========================GNAT BUG DETECTED==============================+
| GPL 2017 (20170515-63) (i686-pc-mingw32) Program_Error
EXCEPTION_ACCESS_VIOLATION|
| Error detected at main.adb:11:4                                          |
| Please submit a bug report by email to rep...@adacore.com.               |
| GAP members can alternatively use GNAT Tracker:                          |
| http://www.adacore.com/ section 'send a report'.                         |
| See gnatinfo.txt for full info on procedure for submitting bugs.         |
| Use a subject line meaningful to you and us to track the bug.            |
| Include the entire contents of this bug box in the report.               |
| Include the exact command that you entered.                              |
| Also include sources listed below.                                       |
| Use plain ASCII or MIME attachment(s).                                   |
+==========================================================================+

Please include these source files with error report
Note that list may not be accurate in some cases,
so please double check that the problem can still
be reproduced with the set of files listed.
Consider also -gnatd.n switch (see debug.adb).

src\main.adb
src\wrappers.ads

compilation abandoned
gprbuild: *** compilation phase failed
************************************************

changing:
   v : Int_Wrappers.Wrapper := Make(50);
to:
   v : Int_Wrappers.Wrapper;

allows compilation.

using "gcc -v -save-temps all-your-options source-file" as instructed only
creates an empty main.s file (attached).

I attached a test case in a .zip