Merge pull request #2622 from scalamacros/pullrequest/paradise

Backport from paradise/macros

3 files changed, 21 insertions, 14 deletions

diff --git a/src/compiler/scala/reflect/macros/util/Helpers.scala b/src/compiler/scala/reflect/macros/util/Helpers.scala
index ada8efa833..9b7680717e 100644
--- a/src/compiler/scala/reflect/macros/util/Helpers.scala
+++ b/src/compiler/scala/reflect/macros/util/Helpers.scala
@@ -54,7 +54,7 @@ trait Helpers {
    *
    *  @see Metalevels.scala for more information and examples about metalevels
    */
-  def increaseMetalevel(pre: Type, tp: Type): Type = dealiasAndRewrap(tp) {
+  def increaseMetalevel(pre: Type, tp: Type): Type = transparentShallowTransform(RepeatedParamClass, tp) {
     case tp => typeRef(pre, MacroContextExprClass, List(tp))
   }
 
@@ -64,8 +64,8 @@ trait Helpers {
    *
    *  @see Metalevels.scala for more information and examples about metalevels
    */
-  def decreaseMetalevel(tp: Type): Type = dealiasAndRewrap(tp) {
+  def decreaseMetalevel(tp: Type): Type = transparentShallowTransform(RepeatedParamClass, tp) {
     case ExprClassOf(runtimeType) => runtimeType
-    case _ => AnyClass.tpe // so that macro impls with rhs = ??? don't screw up our inference
+    case _ => AnyTpe // so that macro impls with rhs = ??? don't screw up our inference
   }
 }
\ No newline at end of file
diff --git a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
index fe1607c631..7fa199afaf 100644
--- a/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/ContextErrors.scala
@@ -782,7 +782,7 @@ trait ContextErrors {
       }
 
       def MacroExpansionHasInvalidTypeError(expandee: Tree, expanded: Any) = {
-        val expected = "expr"
+        val expected = "expr or tree"
         val isPathMismatch = expanded != null && expanded.isInstanceOf[scala.reflect.api.Exprs#Expr[_]]
         macroExpansionError(expandee,
           s"macro must return a compiler-specific $expected; returned value is " + (
diff --git a/src/compiler/scala/tools/nsc/typechecker/Macros.scala b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
index 6c4d1e20aa..86ba3d2164 100644
--- a/src/compiler/scala/tools/nsc/typechecker/Macros.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/Macros.scala
@@ -92,11 +92,12 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
     methName: String,
     // flattens the macro impl's parameter lists having symbols replaced with their fingerprints
     // currently fingerprints are calculated solely from types of the symbols:
-    //   * c.Expr[T] => IMPLPARAM_EXPR
-    //   * c.WeakTypeTag[T] => index of the type parameter corresponding to that type tag
-    //   * everything else (e.g. scala.reflect.macros.Context) => IMPLPARAM_OTHER
+    //   * c.Expr[T] => LiftedTyped
+    //   * c.Tree => LiftedUntyped
+    //   * c.WeakTypeTag[T] => Tagged(index of the type parameter corresponding to that type tag)
+    //   * everything else (e.g. scala.reflect.macros.Context) => Other
     // f.ex. for: def impl[T: WeakTypeTag, U, V: WeakTypeTag](c: Context)(x: c.Expr[T], y: c.Tree): (U, V) = ???
-    // `signature` will be equal to List(List(Other), List(Lifted, Other), List(Tagged(0), Tagged(2)))
+    // `signature` will be equal to List(List(Other), List(LiftedTyped, LiftedUntyped), List(Tagged(0), Tagged(2)))
     signature: List[List[Fingerprint]],
     // type arguments part of a macro impl ref (the right-hand side of a macro definition)
     // these trees don't refer to a macro impl, so we can pickle them as is
@@ -124,7 +125,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
    *        "className" = "Macros$"))
    */
   object MacroImplBinding {
-    val versionFormat = 4.0
+    val versionFormat = 5.0
 
     def pickleAtom(obj: Any): Tree =
       obj match {
@@ -164,7 +165,8 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
       def signature: List[List[Fingerprint]] = {
         def fingerprint(tpe: Type): Fingerprint = tpe.dealiasWiden match {
           case TypeRef(_, RepeatedParamClass, underlying :: Nil) => fingerprint(underlying)
-          case ExprClassOf(_) => Lifted
+          case ExprClassOf(_) => LiftedTyped
+          case TreeType() => LiftedUntyped
           case _ => Other
         }
 
@@ -388,7 +390,8 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
             val wrappedArgs = mapWithIndex(args)((arg, j) => {
               val fingerprint = implParams(min(j, implParams.length - 1))
               fingerprint match {
-                case Lifted => context.Expr[Nothing](arg)(TypeTag.Nothing) // TODO: SI-5752
+                case LiftedTyped => context.Expr[Nothing](arg)(TypeTag.Nothing) // TODO: SI-5752
+                case LiftedUntyped => arg
                 case _ => abort(s"unexpected fingerprint $fingerprint in $binding with paramss being $paramss " +
                                 s"corresponding to arg $arg in $argss")
               }
@@ -690,6 +693,7 @@ trait Macros extends FastTrack with MacroRuntimes with Traces with Helpers {
           }
           expanded match {
             case expanded: Expr[_] if expandee.symbol.isTermMacro => validateResultingTree(expanded.tree)
+            case expanded: Tree if expandee.symbol.isTermMacro => validateResultingTree(expanded)
             case _ => MacroExpansionHasInvalidTypeError(expandee, expanded)
           }
         } catch {
@@ -804,10 +808,12 @@ class Fingerprint(val value: Int) extends AnyVal {
   def paramPos = { assert(isTag, this); value }
   def isTag = value >= 0
   def isOther = this == Other
-  def isExpr = this == Lifted
+  def isExpr = this == LiftedTyped
+  def isTree = this == LiftedUntyped
   override def toString = this match {
     case Other => "Other"
-    case Lifted => "Expr"
+    case LiftedTyped => "Expr"
+    case LiftedUntyped => "Tree"
     case _ => s"Tag($value)"
   }
 }
@@ -815,5 +821,6 @@ class Fingerprint(val value: Int) extends AnyVal {
 object Fingerprint {
   def Tagged(tparamPos: Int) = new Fingerprint(tparamPos)
   val Other = new Fingerprint(-1)
-  val Lifted = new Fingerprint(-2)
+  val LiftedTyped = new Fingerprint(-2)
+  val LiftedUntyped = new Fingerprint(-3)
 }