Some uninteresting code related to error messag...

Some uninteresting code related to error messages, which I'm checking
in mostly because I booted the r23379 commit in a git-svn meltdown and
posterity demands the message, which was:

You can now use the self-type of an anonymous class as a singleton type
in a pattern match ON THE MOON. Actual test case excerpt:

  val x4 = new { self =>
    def f(x: Any) = x match {
      case _: x1.type     => 1
      case _: x2.type     => 2
      case _: x3.type     => 3
      case _: self.type   => 4
      case x: Dingus.type => x.IamDingus
    }
  }

Closes #576, no review.

1 files changed, 10 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
index be576289f6..d5bb546b7f 100644
--- a/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/TypeDiagnostics.scala
@@ -39,6 +39,8 @@ trait TypeDiagnostics {
   import definitions._
   import global.typer.infer
 
+  private def currentUnit = currentRun.currentUnit
+
   /** It can be quite difficult to know which of the many functions called "error"
    *  is being called at any given point in the compiler.  To alleviate this I am
    *  renaming such functions inside this trait based on where it originated.
@@ -53,6 +55,14 @@ trait TypeDiagnostics {
   def noErroneousSyms(syms: Symbol*)  = syms forall (x => !x.isErroneous)
   def noErroneousTrees(trees: Tree*)  = trees forall (x => !x.isErroneous)
 
+  /** For errors which are artifacts of the implementation: such messages
+   *  indicate that the restriction may be lifted in the future.
+   */
+  def restrictionWarning(pos: Position, unit: CompilationUnit, msg: String): Unit =
+    unit.warning(pos, "Implementation restriction: " + msg)
+  def restrictionError(pos: Position, unit: CompilationUnit, msg: String): Unit =
+    unit.error(pos, "Implementation restriction: " + msg)
+
   /** A map of Positions to addendums - if an error involves a position in
    *  the map, the addendum should also be printed.
    */