added annotation checker hook for Types.isWithi...

added annotation checker hook for Types.isWithinBounds. needed to allow
functions of type T => A @cps[B,C] even though A @cps[B,C] is not a
subtype of Any. review by odersky.

2 files changed, 13 insertions, 1 deletions

diff --git a/src/compiler/scala/tools/nsc/symtab/AnnotationCheckers.scala b/src/compiler/scala/tools/nsc/symtab/AnnotationCheckers.scala
index f28fbeca96..945d9aa2fe 100644
--- a/src/compiler/scala/tools/nsc/symtab/AnnotationCheckers.scala
+++ b/src/compiler/scala/tools/nsc/symtab/AnnotationCheckers.scala
@@ -29,6 +29,10 @@ trait AnnotationCheckers {
      *  All this should do is add annotations. */
     def annotationsGlb(tp: Type, ts: List[Type]): Type = tp
 
+    /** Refine the bounds on type parameters to the given type arguments. */
+    def adaptBoundsToAnnotations(bounds: List[TypeBounds],
+      tparams: List[Symbol], targs: List[Type]): List[TypeBounds] = bounds
+
     /** Modify the type that has thus far been inferred
      *  for a tree.  All this should do is add annotations. */
     def addAnnotations(tree: Tree, tpe: Type): Type = tpe
@@ -86,6 +90,12 @@ trait AnnotationCheckers {
       checker.annotationsGlb(tpe, ts))
   }
 
+  /** Refine the bounds on type parameters to the given type arguments. */
+  def adaptBoundsToAnnotations(bounds: List[TypeBounds],
+    tparams: List[Symbol], targs: List[Type]): List[TypeBounds] = {
+      annotationCheckers.foldLeft(bounds)((bounds, checker) =>
+        checker.adaptBoundsToAnnotations(bounds, tparams, targs))
+  }
 
   /** Let all annotations checkers add extra annotations
    *  to this tree's type. */
diff --git a/src/compiler/scala/tools/nsc/symtab/Types.scala b/src/compiler/scala/tools/nsc/symtab/Types.scala
index dc324511fa..ab8c34d44d 100644
--- a/src/compiler/scala/tools/nsc/symtab/Types.scala
+++ b/src/compiler/scala/tools/nsc/symtab/Types.scala
@@ -4589,7 +4589,9 @@ A type's typeSymbol should never be inspected directly.
    *  @return        ...
    */
   def isWithinBounds(pre: Type, owner: Symbol, tparams: List[Symbol], targs: List[Type]): Boolean = {
-    val bounds = instantiatedBounds(pre, owner, tparams, targs)
+    var bounds = instantiatedBounds(pre, owner, tparams, targs)
+    if (targs.exists(_.annotations.nonEmpty))
+      bounds = adaptBoundsToAnnotations(bounds, tparams, targs)
     (bounds corresponds targs)(_ containsType _)  // @PP: corresponds
   }