[Ada] Overriding error on type derived from discriminated untagged private type
Commit Message
When a derived type DT has an untagged private parent type PT with a
discriminant, where the full type of PT is tagged, and DT inherits a
function F with an anonymous access result that designates the type, the
compiler wrongly reports an error saying that DT must be declared
abstract or F overridden. A test is added to exclude checking the
abstract overriding rules that should only apply to inherited
subprograms of tagged derived types.
Tested on x86_64-pc-linux-gnu, committed on trunk
gcc/ada/
* sem_ch3.adb (Check_Abstract_Overriding): If the type is
derived from an untagged type, then don't perform any of the
abstract overriding error checks.
@@ -11047,6 +11047,14 @@ package body Sem_Ch3 is
Subp := Node (Elmt);
Alias_Subp := Alias (Subp);
+ -- If the parent type is untagged, then no overriding error checks
+ -- are needed (such as in the case of an implicit full type for
+ -- a derived type whose parent is an untagged private type with
+ -- a tagged full type).
+
+ if not Is_Tagged_Type (Etype (T)) then
+ null;
+
-- Inherited subprograms are identified by the fact that they do not
-- come from source, and the associated source location is the
-- location of the first subtype of the derived type.
@@ -11065,7 +11073,7 @@ package body Sem_Ch3 is
-- overriding in Ada 2005, but wrappers need to be built for them
-- (see exp_ch3, Build_Controlling_Function_Wrappers).
- if Is_Null_Extension (T)
+ elsif Is_Null_Extension (T)
and then Has_Controlling_Result (Subp)
and then Ada_Version >= Ada_2005
and then Present (Alias_Subp)