[Bug ada/113862] New: error: "others" choice not allowed here

[Bug ada/113862] New: error: "others" choice not allowed here

[p.p11 at orange dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

            Bug ID: 113862
           Summary: error: "others" choice not allowed here
           Product: gcc
           Version: 13.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: p.p11 at orange dot fr
                CC: dkm at gcc dot gnu.org
  Target Milestone: ---

Created attachment 57376
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57376&action=edit
Reproducer.

$ gcc -c -gnatl test34b.adb
GNAT 13.2.0
Compiling: test34b.adb
     1. procedure Test34b is
     2.
     3.    type NTCT is new Natural;
     4.    TBD_Error, Not_Valid_Error : exception;
     5.    function Is_Valid (P : NTCT) return Boolean is (False);
     6.    Param : NTCT;
     7.    type Some_Tagged is tagged null record;
     8.    type A_Tagged is new Some_Tagged with  record Comp : Character; end
record;
     9.    type Some_Array is array (Positive range <>) of NTCT;
    10.    function Func (Val : Integer) return Natural is (0);
    11.
    12.    --    Section_11_3_Paragraph_2a
    13.    Pre : Boolean  := (if not Is_Valid(Param) then raise
Not_Valid_Error);
    14.    A : A_Tagged   := (Some_Tagged'(raise TBD_Error) with Comp => 'A');
    15.    B : Some_Array := (1, 2, 3, others => raise Not_Valid_Error);
                                       |
        >>> error: "others" choice not allowed here
        >>> error: qualify the aggregate with a constrained subtype to provide
bounds for it

    16.    C : Natural    := Func (Val => raise TBD_Error);
    17.    D : A_Tagged   := ((raise TBD_Error) with Comp => 'A');
    18.
    19. begin
    20.    null;
    21. end;

It is weird as this code comes from AARM 2022 Section_11_3_Paragraph_2a.
See full source code in attachement.

[Bug ada/113862] error: "others" choice not allowed here

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2024-02-14
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Not clear if there is much value in creating a PR for such a pathological case
if it happens to be legal.

[Bug ada/113862] error: "others" choice not allowed here

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |SUSPENDED

[Bug ada/113862] error: "others" choice not allowed here

[p.p11 at orange dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

--- Comment #2 from Pascal Pignard <p.p11 at orange dot fr> ---
Nevertheless, theses examples of code come from AARM Ada 2022:
11.3 Raise Statements and Raise Expressions
...
All of the following are legal, no additional parens are needed:

2.a.10/4        Pre : Boolean  := (if not Is_Valid(Param) then raise
Not_Valid_Error);
                A : A_Tagged   := (Some_Tagged'(raise TBD_Error) with Comp =>
'A');
                B : Some_Array := (1, 2, 3, others => raise Not_Valid_Error);
                C : Natural    := Func (Val => raise TBD_Error);

[Bug ada/113862] error: "others" choice not allowed here

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Well, this is very irregular if it happens to be legal, since it would be
illegal if the raise was replaced by anything else.  More of a bug in the
language than in the compiler if you ask me...

[Bug ada/113862] error: "others" choice not allowed here

[charlet at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

Arnaud Charlet <charlet at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |charlet at gcc dot gnu.org
             Status|SUSPENDED                   |RESOLVED
         Resolution|---                         |INVALID

--- Comment #4 from Arnaud Charlet <charlet at gcc dot gnu.org> ---
The AARM example is just wrong, the syntax isn't valid.
The point of this section is to clarify when extra parens are not needed, it
doesn't change the fact that you can't declare an unconstrained array like that
without specifying the bounds, so GNAT's error message is correct.

[Bug ada/113862] error: "others" choice not allowed here

[p.p11 at orange dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113862

--- Comment #5 from Pascal Pignard <p.p11 at orange dot fr> ---
Created attachment 57522
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57522&action=edit
Reproducer updated (no more error)

I apologize the reproducer was wrong, I assumed Some_Array unconstrained
whereas it should have been constrained:
   type Some_Array is array (Positive range 1 .. 10) of NTCT;
Then no more error issue.
I've updated the reproducer.
Sorry for that, Pascal.