===================================================================
@@ -6790,6 +6790,13 @@ package body Sem_Ch3 is
Mark_Rewrite_Insertion (New_Decl);
Insert_Before (N, New_Decl);
+ -- In the tagged case, make sure ancestor is frozen appropriately
+ -- (see also non-discriminated case below).
+
+ if not Private_Extension or else Is_Interface (Parent_Base) then
+ Freeze_Before (New_Decl, Parent_Type);
+ end if;
+
-- Note that this call passes False for the Derive_Subps parameter
-- because subprogram derivation is deferred until after creating
-- the subtype (see below).
@@ -6880,9 +6887,7 @@ package body Sem_Ch3 is
-- The declaration of a specific descendant of an interface type
-- freezes the interface type (RM 13.14).
- if not Private_Extension
- or else Is_Interface (Parent_Base)
- then
+ if not Private_Extension or else Is_Interface (Parent_Base) then
Freeze_Before (N, Parent_Type);
end if;
A record extension always freezes its parent type. However this freezing was erroneously omitted in the case of a tagged private ancestor with discriminants, causing a compiler crash while freezing the derived type. This change adds the missing freeze operation. The following compilation must be accepted cleanly: $ gcc -c derived_from_pvt_disc2.ads package Derived_From_Pvt_Disc2 is package P1 is type T1 (X : Integer) is tagged private; private type T1 (X : Integer) is tagged null record; end P1; type T2 is new P1.T1 (1) with null record; end Derived_From_Pvt_Disc2; Tested on x86_64-pc-linux-gnu, committed on trunk 2010-06-22 Thomas Quinot <quinot@adacore.com> * sem_ch3.adb (Build_Derived_Record_Type): When deriving a tagged private type with discriminants, make sure the parent type is frozen.