Add -Ycheck capability

Right now uses a super-rudementary tree checker: we only check that every tree
has a type.

1 files changed, 37 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/transform/TreeChecker.scala b/src/dotty/tools/dotc/transform/TreeChecker.scala
new file mode 100644
index 000000000..ea3afc679
--- /dev/null
+++ b/src/dotty/tools/dotc/transform/TreeChecker.scala
@@ -0,0 +1,37 @@
+package dotty.tools.dotc
+package transform
+
+import TreeTransforms._
+import core.DenotTransformers._
+import core.Denotations._
+import core.SymDenotations._
+import core.Contexts._
+import core.Symbols._
+import core.Types._
+import core.Constants._
+import core.StdNames._
+import core.transform.Erasure.isUnboundedGeneric
+import typer.ErrorReporting._
+import ast.Trees._
+
+/** This transform eliminates patterns. Right now it's a dummy.
+ *  Awaiting the real pattern matcher.
+ */
+class TreeChecker {
+  import ast.tpd._
+
+  def check(ctx: Context) = {
+    println(s"checking ${ctx.compilationUnit} after phase ${ctx.phase.prev}")
+    Checker.transform(ctx.compilationUnit.tpdTree)(ctx)
+  }
+
+  object Checker extends TreeMap {
+    override def transform(tree: Tree)(implicit ctx: Context) = {
+      println(i"checking $tree")
+      assert(tree.isEmpty || tree.hasType, tree.show)
+      super.transform(tree)
+    }
+  }
+}
+
+object TreeChecker extends TreeChecker
\ No newline at end of file