The Has_Private_View mechanism is also applied to actuals of the
instantiations and there is the same issue for array type actuals whose
component type is the actual of a preceding formal as for global types
whose component type is not referenced in the tree.
This can happen for nested instantiations and in this case we can simply
restore the views of the actuals of the parent instances.
Tested on x86_64-pc-linux-gnu, committed on trunk
2020-06-04 Eric Botcazou <ebotca...@adacore.com>
gcc/ada/
* sem_ch12.adb (Check_Generic_Actuals): Also restore the proper
views of the actuals of the parent instances if the formals are
used as actuals of the children.
(Instantiate_Type): Add comment.--- gcc/ada/sem_ch12.adb
+++ gcc/ada/sem_ch12.adb
@@ -6802,8 +6802,35 @@ package body Sem_Ch12 is
and then Scope (Etype (E)) /= Instance
and then Is_Entity_Name (Subtype_Indication (Parent (E)))
then
+ -- Restore the proper view of the actual from the information
+ -- saved earlier by Instantiate_Type.
+
Check_Private_View (Subtype_Indication (Parent (E)));
+ -- If the actual is itself the formal of a parent instance,
+ -- then also restore the proper view of its actual and so on.
+ -- That's necessary for nested instantiations of the form
+
+ -- generic
+ -- type Component is private;
+ -- type Array_Type is array (Positive range <>) of Component;
+ -- procedure Proc;
+
+ -- when the outermost actuals have inconsistent views, because
+ -- the Component_Type of Array_Type of the inner instantiations
+ -- is the actual of Component of the outermost one and not that
+ -- of the corresponding inner instantiations.
+
+ Astype := Ancestor_Subtype (E);
+ while Present (Astype)
+ and then Nkind (Parent (Astype)) = N_Subtype_Declaration
+ and then Present (Generic_Parent_Type (Parent (Astype)))
+ and then Is_Entity_Name (Subtype_Indication (Parent (Astype)))
+ loop
+ Check_Private_View (Subtype_Indication (Parent (Astype)));
+ Astype := Ancestor_Subtype (Astype);
+ end loop;
+
Set_Is_Generic_Actual_Type (E);
if Is_Private_Type (E) and then Present (Full_View (E)) then
@@ -13603,6 +13630,10 @@ package body Sem_Ch12 is
Defining_Identifier => Subt,
Subtype_Indication => New_Occurrence_Of (Act_T, Loc));
+ -- Record whether the actual is private at this point, so that
+ -- Check_Generic_Actuals can restore its proper view before the
+ -- semantic analysis of the instance.
+
if Is_Private_Type (Act_T) then
Set_Has_Private_View (Subtype_Indication (Decl_Node));
end if;
