[Bug ada/106168] New: Errors with empty array aggregate.

[Bug ada/106168] New: Errors with empty array aggregate.

[p.p11 at orange dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106168

            Bug ID: 106168
           Summary: Errors with empty array aggregate.
           Product: gcc
           Version: 12.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ada
          Assignee: unassigned at gcc dot gnu.org
          Reporter: p.p11 at orange dot fr
  Target Milestone: ---

Created attachment 53239
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53239&action=edit
Full source code

Following the example section of RM Ada 2022 § 4.3.3 Array Aggregate, the empty
aggregate is line 8:

3.    type Real is digits 8;
4.    type Matrix is array (Integer range <>, Integer range <>) of Real;
5. 
6.    -- AARM (Draft 22) Section_4_3_3_Paragraph_47
7.    
8.    Empty_Matrix : constant Matrix := []; -- A matrix without elements

GNAT 12.1.0 issues the following errors:
% gcc -c -gnat2022 2022/test_20220702_array_agg.adb
test_20220702_array_agg.adb:8:38: error: value not in range of type
"Standard.Integer"
test_20220702_array_agg.adb:8:38: error: static expression fails
Constraint_Check

[Bug ada/106168] Errors with empty array aggregate.

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106168

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2023-05-11
                 CC|                            |ebotcazou at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1

--- Comment #2 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
GCC 13 gives a different message:

p.adb:8:38: warning: Pred of "Integer'First" [enabled by default]
p.adb:8:38: warning: Constraint_Error will be raised at run time [enabled by
default]

[Bug ada/106168] Errors with empty array aggregate.

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106168

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
   Target Milestone|---                         |13.0
             Status|NEW                         |RESOLVED

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
That's expected, you need to replace Integer with Positive for example.

[Bug ada/106168] Errors with empty array aggregate.

[p.p11 at orange dot fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106168

Pascal Pignard <p.p11 at orange dot fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|FIXED                       |---

--- Comment #4 from Pascal Pignard <p.p11 at orange dot fr> ---
That's suppress the warnings.
But it remains strange as the example came from the Ada 2022 standard, see 3.6
Array Types, Examples at §26 and 4.3.3 Array Aggregates, Examples at § 47/5.
Is it correct?

[Bug ada/106168] Errors with empty array aggregate.

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106168

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|REOPENED                    |SUSPENDED

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Probably not, but I'm not sure we can do better for now.