objects with no ancestor are not implicitely final

lib/pure/pegs.nim

@@ -1057,7 +1057,7 @@ type
     charset: set[char]       ## if kind == tkCharSet
     index: int               ## if kind == tkBackref
   
-  TPegLexer = object          ## the lexer object.
+  TPegLexer {.inheritable.} = object          ## the lexer object.
     bufpos: int               ## the current position within the buffer
     buf: cstring              ## the buffer itself
     LineNumber: int           ## the current line number

lib/pure/xmldom.nim

@@ -58,7 +58,7 @@ type
     Features: seq[Feature] # Read-Only
 
   PNode* = ref Node
-  Node = object
+  Node = object of TObject
     attributes*: seq[PAttr]
     childNodes*: seq[PNode]
     FLocalName: string # Read-only

lib/system.nim

@@ -171,9 +171,12 @@ proc `..`*[T](b: T): TSlice[T] {.noSideEffect, inline.} =
 proc contains*[T](s: TSlice[T], value: T): bool {.noSideEffect, inline.} = 
   result = value >= s.a and value <= s.b
 
+when not defined(niminheritable):
+  {.pragma: inheritable.}
+
 when not defined(EcmaScript) and not defined(NimrodVM):
   type
-    TGenericSeq {.compilerproc, pure.} = object
+    TGenericSeq {.compilerproc, pure, inheritable.} = object
       len, reserved: int
     PGenericSeq {.exportc.} = ptr TGenericSeq
     # len and space without counting the terminating zero:
@@ -197,7 +200,7 @@ type
     ## is an int type ranging from one to the maximum value
     ## of an int. This type is often useful for documentation and debugging.
 
-  TObject* {.exportc: "TNimObject".} =
+  TObject* {.exportc: "TNimObject", inheritable.} =
     object ## the root of Nimrod's object hierarchy. Objects should
            ## inherit from TObject or one of its descendants. However,
            ## objects that have no ancestor are allowed.

lib/system/alloc.nim

@@ -113,7 +113,7 @@ type
   PChunk = ptr TBaseChunk
   PBigChunk = ptr TBigChunk
   PSmallChunk = ptr TSmallChunk
-  TBaseChunk {.pure.} = object
+  TBaseChunk {.pure, inheritable.} = object
     prevSize: int        # size of previous chunk; for coalescing
     size: int            # if < PageSize it is a small chunk
     used: bool           # later will be optimized into prevSize...

lib/wrappers/gtk/glib2.nim

@@ -107,7 +107,7 @@ type
     g_class*: PGTypeClass
 
   PGTypeInterface* = ptr TGTypeInterface
-  TGTypeInterface*{.pure.} = object 
+  TGTypeInterface*{.pure, inheritable.} = object 
     g_type*: GType
     g_instance_type*: GType
 
@@ -993,7 +993,7 @@ proc plugin_complete_interface_info*(plugin: PGTypePlugin,
     dynlib: gliblib, importc: "g_type_plugin_complete_interface_info".}
 type 
   PGObject* = ptr TGObject
-  TGObject*{.pure.} = object 
+  TGObject*{.pure, inheritable.} = object 
     g_type_instance*: TGTypeInstance
     ref_count*: guint
     qdata*: PGData
@@ -1006,7 +1006,7 @@ type
   TGWeakNotify* = proc (data: gpointer, where_the_object_was: PGObject){.cdecl.}
   PGObjectConstructParam* = ptr TGObjectConstructParam
   PGObjectClass* = ptr TGObjectClass
-  TGObjectClass*{.pure.} = object 
+  TGObjectClass*{.pure, inheritable.} = object 
     g_type_class*: TGTypeClass
     construct_properties*: PGSList
     constructor*: proc (theType: GType, n_construct_properties: guint, 

lib/wrappers/python.nim

@@ -341,7 +341,7 @@ type
     float*: float64
     imag*: float64
 
-  TPyObject*{.pure.} = object 
+  TPyObject*{.pure, inheritable.} = object 
     ob_refcnt*: int
     ob_type*: PPyTypeObject