macro impls can now return subtypes of c.Tree

10229316db allowed macro impls to take and return values of type c.Tree
in addition to the usual c.Expr. However it didn't take into account that
it is often useful to return subtypes of trees (e.g. with quasiquotes
that expand into expressions typed as precisely as possible). This patch
fixes that oversight.

1 files changed, 2 insertions, 4 deletions

diff --git a/src/reflect/scala/reflect/internal/Definitions.scala b/src/reflect/scala/reflect/internal/Definitions.scala
index d3b9c38ee1..6a9fa9a884 100644
--- a/src/reflect/scala/reflect/internal/Definitions.scala
+++ b/src/reflect/scala/reflect/internal/Definitions.scala
@@ -492,10 +492,8 @@ trait Definitions extends api.StandardDefinitions {
 
     lazy val TreesClass            = getClassIfDefined("scala.reflect.api.Trees") // defined in scala-reflect.jar, so we need to be careful
     lazy val TreesTreeType         = TreesClass.map(sym => getTypeMember(sym, tpnme.Tree))
-    object TreeType {
-      def unapply(tpe: Type): Boolean = unapply(tpe.typeSymbol)
-      def unapply(sym: Symbol): Boolean = sym.overrideChain contains TreesTreeType
-    }
+    object TreeType { def unapply(tpe: Type): Boolean = tpe.typeSymbol.overrideChain contains TreesTreeType }
+    object SubtreeType { def unapply(tpe: Type): Boolean = tpe.typeSymbol.overrideChain exists (_.tpe <:< TreesTreeType.tpe) }
 
     lazy val ExprsClass            = getClassIfDefined("scala.reflect.api.Exprs") // defined in scala-reflect.jar, so we need to be careful
     lazy val ExprClass             = ExprsClass.map(sym => getMemberClass(sym, tpnme.Expr))