Move compiler and compiler tests to compiler dir

1 files changed, 42 insertions, 0 deletions

diff --git a/compiler/src/dotty/tools/backend/jvm/CollectSuperCalls.scala b/compiler/src/dotty/tools/backend/jvm/CollectSuperCalls.scala
new file mode 100644
index 000000000..8285bfe4b
--- /dev/null
+++ b/compiler/src/dotty/tools/backend/jvm/CollectSuperCalls.scala
@@ -0,0 +1,42 @@
+package dotty.tools.backend.jvm
+
+import dotty.tools.dotc.ast.tpd
+import dotty.tools.dotc.ast.Trees._
+import dotty.tools.dotc.core.Contexts.Context
+import dotty.tools.dotc.core.Symbols._
+import dotty.tools.dotc.core.Flags.Trait
+import dotty.tools.dotc.transform.TreeTransforms.{MiniPhaseTransform, TransformerInfo}
+
+/** Collect all super calls to trait members.
+ *
+ *  For each super reference to trait member, register a call from the current class to the
+ *  owner of the referenced member.
+ *
+ *  This information is used to know if it is safe to remove a redundant mixin class.
+ *  A redundant mixin class is one that is implemented by another mixin class. As the
+ *  methods in a redundant mixin class could be implemented with a default abstract method,
+ *  the redundant mixin class could be required as a parent by the JVM.
+ */
+class CollectSuperCalls extends MiniPhaseTransform {
+  import tpd._
+
+  def phaseName: String = "collectSuperCalls"
+
+  override def transformSelect(tree: Select)(implicit ctx: Context, info: TransformerInfo): Tree = {
+    tree.qualifier match {
+      case sup: Super =>
+        if (tree.symbol.owner.is(Trait))
+          registerSuperCall(ctx.owner.enclosingClass.asClass, tree.symbol.owner.asClass)
+      case _ =>
+    }
+    tree
+  }
+
+  private def registerSuperCall(sym: ClassSymbol, calls: ClassSymbol)(implicit ctx: Context) = {
+    ctx.genBCodePhase match {
+      case genBCodePhase: GenBCode =>
+        genBCodePhase.registerSuperCall(sym, calls)
+      case _ =>
+    }
+  }
+}