Split Nullarify functionality to ElimByName, Erasure

New phase ElimByName elimintaes by-name parameters. All other
occurrences of parameterless methods and ExprTypes are eliminated
in erasure.

The reason for the split like this is that it is very hard for
Nullarify to determine when to insert ()'s. The logic for this
is fragile because we need to look at previous denotations which might
not exist (before splitter) or might result from a merge
between parameterless and nullary methods. In Erasure
the same is much simpler to achieve.

1 files changed, 25 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/transform/SymUtils.scala b/src/dotty/tools/dotc/transform/SymUtils.scala
new file mode 100644
index 000000000..e5dfd4d4e
--- /dev/null
+++ b/src/dotty/tools/dotc/transform/SymUtils.scala
@@ -0,0 +1,25 @@
+package dotty.tools.dotc
+package transform
+
+import core._
+import core.transform.Erasure.ErasedValueType
+import Types._
+import Contexts._
+import Symbols._
+import Decorators._
+import StdNames.nme
+import NameOps._
+import language.implicitConversions
+
+object SymUtils {
+  implicit def decorateSymUtils(sym: Symbol): SymUtils = new SymUtils(sym)
+}
+
+/** A decorator that provides methods on symbols
+ *  that are needed in the transformer pipeline.
+ */
+class SymUtils(val self: Symbol) extends AnyVal {
+
+  def isTypeTestOrCast(implicit ctx: Context): Boolean =
+    self == defn.Any_asInstanceOf || self == defn.Any_isInstanceOf
+}