Merge pull request #2333 from def-/recursive-type

Fix infinite recursion in semtypes with recursive types

compiler/semtypes.nim

@@ -787,6 +787,8 @@ proc liftParamType(c: PContext, procKind: TSymKind, genericParams: PNode,
       result = addImplicitGeneric(typ)
     else:
       for i in 0 .. <paramType.sons.len:
+        if paramType.sons[i] == paramType:
+          globalError(info, errIllegalRecursionInTypeX, typeToString(paramType))
         var lifted = liftingWalk(paramType.sons[i])
         if lifted != nil:
           paramType.sons[i] = lifted

tests/types/tinfiniterecursion.nim

@@ -0,0 +1,8 @@
+discard """
+  errormsg: "illegal recursion in type 'XIM'"
+  line: 8
+"""
+
+type
+  XIM* = ptr XIM
+  XIMProc* = proc (a2: XIM)