gigi.h (standard_datatypes): Add ADT_fdesc_type and ADT_null_fdesc.

	* gigi.h (standard_datatypes): Add ADT_fdesc_type and ADT_null_fdesc.
	(fdesc_type_node): Define.
	(null_fdesc_node): Likewise.
	* decl.c (gnat_to_gnu_entity) <E_Access_Subprogram_Type>: If the target
	uses descriptors for vtables and the type comes from a dispatch table,
	return the descriptor type.
	* trans.c (Attribute_to_gnu) <Attr_Unrestricted_Access>: If the target
	uses descriptors for vtables and the type comes from a dispatch table,
	build a descriptor in the static case and copy the existing one in the
	non-static case.
	(gnat_to_gnu) <N_Null>: If the target uses descriptors for vtables and
	the type is a pointer-to-subprogram coming from a dispatch table,
	return the null descriptor.
	<N_Unchecked_Type_Conversion>: If the target uses descriptors for
	vtables, the source type is the descriptor type and the target type
	is a pointer type, first build the pointer.
	* utils.c (init_gigi_decls): If the target uses descriptors for vtables
	build the descriptor type and the null descriptor.

From-SVN: r134101

1 files changed, 16 insertions, 0 deletions

diff --git a/gcc/ada/decl.c b/gcc/ada/decl.c
index 545730b..aca69ff 100644
--- a/gcc/ada/decl.c
+++ b/gcc/ada/decl.c
@@ -3089,6 +3089,22 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
       break;
 
     case E_Access_Subprogram_Type:
+      /* Use the special descriptor type for dispatch tables if needed,
+	 that is to say for the Prim_Ptr of a-tags.ads and its clones.
+	 Note that we are only required to do so for static tables in
+	 order to be compatible with the C++ ABI, but Ada 2005 allows
+	 to extend library level tagged types at the local level so
+	 we do it in the non-static case as well.  */
+      if (TARGET_VTABLE_USES_DESCRIPTORS
+	  && Is_Dispatch_Table_Entity (gnat_entity))
+	{
+	    gnu_type = fdesc_type_node;
+	    gnu_size = TYPE_SIZE (gnu_type);
+	    break;
+	}
+
+      /* ... fall through ... */
+
     case E_Anonymous_Access_Subprogram_Type:
       /* If we are not defining this entity, and we have incomplete
 	 entities being processed above us, make a dummy type and