ada: Fix detection of components with per-object constraints

Routine Contains_POC (where POC means "per-object constraint") was
failing to detect expressions of the form "Current_Type'Access", because
it was comparing prefix (typically an N_Identifier) with a scope
(typically an N_Definining_Entity). This was harmless, because these
expressions are detected anyway in Analyze_Access_Attribute, together
with uses of 'Unconstrained_Access and 'Unchecked_Access.

Also, this routine was failing to detect the use of discriminants in
array types with constrained subtype indication, e.g.:

  type T (D : Integer) is record
     C : array (Integer range 1 .. D);
  end record;

It is simpler to just reuse Has_Discriminant_Dependent_Constraint and
leave detection of access attributes to Analyze_Access_Attribute.

gcc/ada/

	* sem_attr.adb (Analyze_Access_Attribute): Prevent search from
	going too far.
	* sem_ch3.adb (Analyze_Component_Declaration): Remove
	Contains_POC; reuse Has_Discriminant_Dependent_Constraint.

2 files changed, 14 insertions, 80 deletions

diff --git a/gcc/ada/sem_attr.adb b/gcc/ada/sem_attr.adb
index c067d88..c17f673 100644
--- a/gcc/ada/sem_attr.adb
+++ b/gcc/ada/sem_attr.adb
@@ -1014,16 +1014,20 @@ package body Sem_Attr is
                      Q : Node_Id := Parent (N);
 
                   begin
-                     while Present (Q)
-                       and then Nkind (Q) /= N_Component_Declaration
-                     loop
+                     while Present (Q) loop
+                        if Nkind (Q) = N_Component_Declaration then
+                           Set_Has_Per_Object_Constraint
+                             (Defining_Identifier (Q), True);
+                           exit;
+
+                        --  Prevent the search from going too far
+
+                        elsif Is_Body_Or_Package_Declaration (Q) then
+                           exit;
+                        end if;
+
                         Q := Parent (Q);
                      end loop;
-
-                     if Present (Q) then
-                        Set_Has_Per_Object_Constraint
-                          (Defining_Identifier (Q), True);
-                     end if;
                   end;
 
                   if Nkind (P) = N_Expanded_Name then
diff --git a/gcc/ada/sem_ch3.adb b/gcc/ada/sem_ch3.adb
index 737ea80..ad9e931 100644
--- a/gcc/ada/sem_ch3.adb
+++ b/gcc/ada/sem_ch3.adb
@@ -1960,71 +1960,11 @@ package body Sem_Ch3 is
       T   : Entity_Id;
       P   : Entity_Id;
 
-      function Contains_POC (Constr : Node_Id) return Boolean;
-      --  Determines whether a constraint uses the discriminant of a record
-      --  type thus becoming a per-object constraint (POC).
-
       function Is_Known_Limited (Typ : Entity_Id) return Boolean;
       --  Typ is the type of the current component, check whether this type is
       --  a limited type. Used to validate declaration against that of
       --  enclosing record.
 
-      ------------------
-      -- Contains_POC --
-      ------------------
-
-      function Contains_POC (Constr : Node_Id) return Boolean is
-      begin
-         --  Prevent cascaded errors
-
-         if Error_Posted (Constr) then
-            return False;
-         end if;
-
-         case Nkind (Constr) is
-            when N_Attribute_Reference =>
-               return Attribute_Name (Constr) = Name_Access
-                 and then Prefix (Constr) = Scope (Entity (Prefix (Constr)));
-
-            when N_Discriminant_Association =>
-               return Denotes_Discriminant (Expression (Constr));
-
-            when N_Identifier =>
-               return Denotes_Discriminant (Constr);
-
-            when N_Index_Or_Discriminant_Constraint =>
-               declare
-                  IDC : Node_Id;
-
-               begin
-                  IDC := First (Constraints (Constr));
-                  while Present (IDC) loop
-
-                     --  One per-object constraint is sufficient
-
-                     if Contains_POC (IDC) then
-                        return True;
-                     end if;
-
-                     Next (IDC);
-                  end loop;
-
-                  return False;
-               end;
-
-            when N_Range =>
-               return Denotes_Discriminant (Low_Bound (Constr))
-                        or else
-                      Denotes_Discriminant (High_Bound (Constr));
-
-            when N_Range_Constraint =>
-               return Denotes_Discriminant (Range_Expression (Constr));
-
-            when others =>
-               return False;
-         end case;
-      end Contains_POC;
-
       ----------------------
       -- Is_Known_Limited --
       ----------------------
@@ -2208,18 +2148,8 @@ package body Sem_Ch3 is
       --  The component declaration may have a per-object constraint, set
       --  the appropriate flag in the defining identifier of the subtype.
 
-      if Present (Subtype_Indication (Component_Definition (N))) then
-         declare
-            Sindic : constant Node_Id :=
-                       Subtype_Indication (Component_Definition (N));
-         begin
-            if Nkind (Sindic) = N_Subtype_Indication
-              and then Present (Constraint (Sindic))
-              and then Contains_POC (Constraint (Sindic))
-            then
-               Set_Has_Per_Object_Constraint (Id);
-            end if;
-         end;
+      if Has_Discriminant_Dependent_Constraint (Id) then
+         Set_Has_Per_Object_Constraint (Id);
       end if;
 
       --  Ada 2005 (AI-231): Propagate the null-excluding attribute and carry