toplevel .closure procs are deprecated

compiler/semstmts.nim

@@ -1220,6 +1220,9 @@ proc semProcAux(c: PContext, n: PNode, kind: TSymKind,
   if n.sons[patternPos].kind != nkEmpty:
     c.patterns.add(s)
   if isAnon: result.typ = s.typ
+  if isTopLevel(c) and s.kind != skClosureIterator and
+      s.typ.callConv == ccClosure:
+    message(s.info, warnDeprecated, "top level '.closure' calling convention")
 
 proc determineType(c: PContext, s: PSym) =
   if s.typ != nil: return

todo.txt

@@ -1,7 +1,6 @@
 version 0.11.4
 ==============
 
-- deprecate toplevel .closure procs
 - deprecate closure iterator construction via ``var cl = foo``
 
 - document special cased varargs[untyped] and varargs[typed]

web/news.txt

@@ -46,6 +46,10 @@ News
     overloaded, so we removed it with no deprecation cycle.
   - To use the ``parallel`` statement you now have to
     use the ``--experimental`` mode.
+  - Toplevel procs of calling convention ``closure`` never worked reliably
+    and are now deprecated and will be removed from the language. Instead you
+    have to insert type conversions
+    like ``(proc (a, b: int) {.closure.})(myToplevelProc)`` if necessary.