fixes #2509

compiler/renderer.nim

@@ -503,6 +503,7 @@ proc gsub(g: var TSrcGen, n: PNode) =
 
 proc hasCom(n: PNode): bool =
   result = false
+  if n.isNil: return false
   if n.comment != nil: return true
   case n.kind
   of nkEmpty..nkNilLit: discard

compiler/seminst.nim

@@ -176,7 +176,9 @@ proc instantiateProcType(c: PContext, pt: TIdTable,
 
   for i in 1 .. <result.len:
     # twrong_field_caching requires these 'resetIdTable' calls:
-    if i > 1: resetIdTable(cl.symMap)
+    if i > 1:
+      resetIdTable(cl.symMap)
+      resetIdTable(cl.localCache)
     result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
     propagateToOwner(result, result.sons[i])
     internalAssert originalParams[i].kind == nkSym
@@ -196,6 +198,7 @@ proc instantiateProcType(c: PContext, pt: TIdTable,
       addDecl(c, result.n.sons[i].sym)
 
   resetIdTable(cl.symMap)
+  resetIdTable(cl.localCache)
   result.sons[0] = replaceTypeVarsT(cl, result.sons[0])
   result.n.sons[0] = originalParams[0].copyTree
 

compiler/sempass2.nim

@@ -764,7 +764,7 @@ proc track(tracked: PEffects, n: PNode) =
     setLen(tracked.locked, oldLocked)
     tracked.currLockLevel = oldLockLevel
   of nkTypeSection, nkProcDef, nkConverterDef, nkMethodDef, nkIteratorDef,
-      nkMacroDef, nkTemplateDef:
+      nkMacroDef, nkTemplateDef, nkLambda, nkDo:
     discard
   else:
     for i in 0 .. <safeLen(n): track(tracked, n.sons[i])

compiler/semtypinst.nim

@@ -418,15 +418,23 @@ proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType): PType =
     result = t
 
   of tyGenericInst:
+    result = PType(idTableGet(cl.localCache, t))
+    if result != nil: return result
     result = instCopyType(cl, t)
+    idTablePut(cl.localCache, t, result)
     for i in 1 .. <result.sonsLen:
       result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
     propagateToOwner(result, result.lastSon)
 
   else:
     if containsGenericType(t):
+      #if not cl.allowMetaTypes:
+      result = PType(idTableGet(cl.localCache, t))
+      if result != nil: return result
       result = instCopyType(cl, t)
       result.size = -1 # needs to be recomputed
+      #if not cl.allowMetaTypes:
+      idTablePut(cl.localCache, t, result)
 
       for i in countup(0, sonsLen(result) - 1):
         if result.sons[i] != nil:

tests/generics/twrong_generic_object.nim

@@ -0,0 +1,21 @@
+discard """
+  errormsg: "cannot instantiate: 'GenericNodeObj'"
+  line: 21
+"""
+# bug #2509
+type
+  GenericNodeObj[T] = ref object
+    obj: T
+
+  Node* = ref object
+    children*: seq[Node]
+    parent*: Node
+
+    nodeObj*: GenericNodeObj # [int]
+
+proc newNode*(nodeObj: GenericNodeObj): Node =
+  result = Node(nodeObj: nodeObj)
+  newSeq(result.children, 10)
+
+var genericObj = GenericNodeObj[int]()
+var myNode = newNode(genericObj)

tests/objects/trefobjsyntax2.nim

@@ -0,0 +1,19 @@
+# bug #2508
+
+type
+  GenericNodeObj[T] = ref object
+    obj: T
+
+  Node* = ref object
+    children*: seq[Node]
+    parent*: Node
+
+    nodeObj*: GenericNodeObj[int]
+
+proc newNode*(nodeObj: GenericNodeObj): Node =
+    result = Node(nodeObj: nodeObj)
+    newSeq(result.children, 10)
+
+var genericObj = GenericNodeObj[int]()
+
+var myNode = newNode(genericObj)