Merge pull request #2712 from nanoant/patch/macros-introduce-typenode-for-typedesc

Macros: Introduce typeNode(t: typedesc): NimNode

lib/core/macros.nim

@@ -177,6 +177,12 @@ proc getType*(n: NimNode): NimNode {.magic: "NGetType", noSideEffect.}
   ## resolve recursive types, you have to call 'getType' again. To see what
   ## kind of type it is, call `typeKind` on getType's result.
 
+proc getType*(n: typedesc): NimNode {.magic: "NGetType", noSideEffect.}
+  ## Returns the Nim type node for given type. This can be used to turn macro
+  ## typedesc parameter into proper NimNode representing type, since typedesc
+  ## are an exception in macro calls - they are not mapped implicitly to
+  ## NimNode like any other arguments.
+
 proc typeKind*(n: NimNode): NimTypeKind {.magic: "NGetType", noSideEffect.}
   ## Returns the type kind of the node 'n' that should represent a type, that
   ## means the node should have been obtained via `getType`.

tests/macros/tgettype.nim

@@ -0,0 +1,20 @@
+discard """
+msg: '''ObjectTy(Sym(Model), RecList(Sym(name), Sym(password)))
+BracketExpr(Sym(typeDesc), Sym(User))'''
+"""
+import strutils, macros
+
+type
+  Model = object of RootObj
+  User = object of Model
+    name : string
+    password : string
+
+macro testUser: expr =
+  return newLit(User.getType.lispRepr)
+
+macro testGeneric(T: typedesc[Model]): expr =
+  return newLit(T.getType.lispRepr)
+
+echo testUser
+echo User.testGeneric