fixes #3357

compiler/vmgen.nim

@@ -1377,10 +1377,13 @@ proc genCheckedObjAccess(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
   genObjAccess(c, n.sons[0], dest, flags)
 
 proc genArrAccess(c: PCtx; n: PNode; dest: var TDest; flags: TGenFlags) =
-  if n.sons[0].typ.skipTypes(abstractVarRange-{tyTypeDesc}).kind in {
-      tyString, tyCString}:
+  let arrayType = n.sons[0].typ.skipTypes(abstractVarRange-{tyTypeDesc}).kind
+  if arrayType in {tyString, tyCString}:
     genArrAccess2(c, n, dest, opcLdStrIdx, {})
+  elif arrayType == tyTypeDesc:
+    c.genTypeLit(n.typ, dest)
   else:
+    echo renderTree(n)
     genArrAccess2(c, n, dest, opcLdArr, flags)
 
 proc getNullValueAux(obj: PNode, result: PNode) =

tests/vm/tyaytypedesc.nim

@@ -0,0 +1,21 @@
+discard """
+  output: "ntWhitespace"
+"""
+
+# bug #3357
+
+type NodeType* = enum
+  ntWhitespace
+
+type TokenType* = enum
+  ttWhitespace
+
+proc enumTable*[A, B, C](a: openarray[tuple[key: A, val: B]], ret: typedesc[C]): C =
+  for item in a:
+    result[item.key] = item.val
+
+const tokenTypeToNodeType = {
+  ttWhitespace: ntWhitespace,
+}.enumTable(array[ttWhitespace..ttWhitespace, NodeType])
+
+echo tokenTypeToNodeType[ttWhitespace]