As explained in the head comment of Compatible_Types_In_Predicate,
anomalies involving private and full views can occur when a call
to a predicate or invariant function is generated by the compiler.
The function uses the child function Common_Type to reconcile the
various views of a private type, but this latter function does not
consider the Underlying_Full_View of private types, so it can miss
some cases like this one.
Tested on x86_64-pc-linux-gnu, committed on trunk
2020-06-16 Eric Botcazou <ebotca...@adacore.com>
gcc/ada/
* sem_ch4.adb (Common_Type): Go to Underlying_Full_View, if any.--- gcc/ada/sem_ch4.adb
+++ gcc/ada/sem_ch4.adb
@@ -3291,20 +3291,30 @@ package body Sem_Ch4 is
T2 : Entity_Id) return Boolean
is
function Common_Type (T : Entity_Id) return Entity_Id;
- -- Find non-private full view if any, without going to ancestor type
- -- (as opposed to Underlying_Type).
+ -- Find non-private underlying full view if any, without going to
+ -- ancestor type (as opposed to Underlying_Type).
-----------------
-- Common_Type --
-----------------
function Common_Type (T : Entity_Id) return Entity_Id is
+ CT : Entity_Id;
+
begin
- if Is_Private_Type (T) and then Present (Full_View (T)) then
- return Base_Type (Full_View (T));
- else
- return Base_Type (T);
+ CT := T;
+
+ if Is_Private_Type (CT) and then Present (Full_View (CT)) then
+ CT := Full_View (CT);
end if;
+
+ if Is_Private_Type (CT)
+ and then Present (Underlying_Full_View (CT))
+ then
+ CT := Underlying_Full_View (CT);
+ end if;
+
+ return Base_Type (CT);
end Common_Type;
-- Start of processing for Compatible_Types_In_Predicate
