[gcc r16-1206] ada: Fix for validity checking of limited scalar types

[Marc Poulhies]

https://gcc.gnu.org/g:b449898970a502d31f30334cf0dd630f93d12bd8

commit r16-1206-gb449898970a502d31f30334cf0dd630f93d12bd8
Author: Piotr Trojanek <trojanek@adacore.com>
Date:   Tue Jan 28 12:12:23 2025 +0100

    ada: Fix for validity checking of limited scalar types
    
    With a recent change we are now validity checking objects of private scalar
    types, but need to handle private scalar types whose public view is limited.
    
    gcc/ada/ChangeLog:
    
            * checks.adb (Insert_Valid_Check): Set flag Assignment_OK in the object
            declaration inserted for the validity checks.

Diff:
---
 gcc/ada/checks.adb | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/gcc/ada/checks.adb b/gcc/ada/checks.adb
index dcfcaa33bcc4..6a98292d1cc1 100644
--- a/gcc/ada/checks.adb
+++ b/gcc/ada/checks.adb
@@ -8163,6 +8163,7 @@ package body Checks is
       end if;
 
       declare
+         Decl   : Node_Id;
          CE     : Node_Id;
          PV     : Node_Id;
          Var_Id : Entity_Id;
@@ -8215,12 +8216,20 @@ package body Checks is
             Mutate_Ekind (Var_Id, E_Variable);
             Set_Etype (Var_Id, Typ);
 
-            Insert_Action (Exp,
+            Decl :=
               Make_Object_Declaration (Loc,
                 Defining_Identifier => Var_Id,
                 Object_Definition   => New_Occurrence_Of (Typ, Loc),
-                Expression          => New_Copy_Tree (Exp)),
-              Suppress => Validity_Check);
+                Expression          => New_Copy_Tree (Exp));
+
+            --  We might be validity-checking object whose type is declared as
+            --  limited but completion is a scalar type. We need to explicitly
+            --  flag its assignment as OK, as otherwise it would be rejected by
+            --  the language rules.
+
+            Set_Assignment_OK (Decl);
+
+            Insert_Action (Exp, Decl, Suppress => Validity_Check);
 
             Set_Validated_Object (Var_Id, New_Copy_Tree (Exp));