add back classic reporter

Author: liufengyun

src/dotty/tools/dotc/reporting/ClassicReporter.scala

@@ -0,0 +1,85 @@
+package dotty.tools
+package dotc
+package reporting
+
+import scala.collection.mutable
+import util.SourcePosition
+import core.Contexts._
+import Reporter._
+import java.io.{ BufferedReader, IOException, PrintWriter }
+import scala.reflect.internal.util._
+import diagnostic.{ Message, MessageContainer, NoExplanation }
+import diagnostic.messages._
+
+/**
+ * This class implements a Reporter that displays messages on a text
+ * console.
+ */
+class ClassicReporter(
+    reader: BufferedReader = Console.in,
+    writer: PrintWriter = new PrintWriter(Console.err, true))
+  extends Reporter with UniqueMessagePositions with HideNonSensicalMessages {
+
+  import MessageContainer._
+
+  /** maximal number of error messages to be printed */
+  protected def ErrorLimit = 100
+
+  def printPos(pos: SourcePosition): Unit =
+    if (pos.exists) {
+      printMessage(pos.lineContent.stripLineEnd)
+      printMessage(" " * pos.column + "^")
+      if (pos.outer.exists) {
+        printMessage(s"\n... this location is in code that was inlined at ${pos.outer}:\n")
+        printPos(pos.outer)
+      }
+    }
+
+  /** Prints the message. */
+  def printMessage(msg: String): Unit = { writer.print(msg + "\n"); writer.flush() }
+
+  /** Prints the message with the given position indication. */
+  def printMessageAndPos(msg: String, pos: SourcePosition)(implicit ctx: Context): Unit = {
+    val posStr = if (pos.exists) s"$pos: " else ""
+    printMessage(posStr + msg)
+    printPos(pos)
+  }
+
+  override def doReport(m: MessageContainer)(implicit ctx: Context): Unit = m match {
+    case m: Error =>
+      printMessageAndPos(s"error: ${m.contained}", m.pos)
+      if (ctx.settings.prompt.value) displayPrompt()
+    case m: ConditionalWarning if !m.enablingOption.value =>
+    case m: FeatureWarning =>
+      printMessageAndPos(s"feature warning: ${m.contained.msg}", m.pos)
+    case m: DeprecationWarning =>
+      printMessageAndPos(s"deprecation warning: ${m.contained.msg}", m.pos)
+    case m: UncheckedWarning =>
+      printMessageAndPos(s"unchecked warning: ${m.contained.msg}", m.pos)
+    case m: Info =>
+      printMessageAndPos(m.contained.msg, m.pos)
+    case m: MigrationWarning =>
+      printMessageAndPos(s"migration warning: ${m.contained.msg}", m.pos)
+    case m: Warning =>
+      printMessageAndPos(s"warning: ${m.contained.msg}", m.pos)
+    case _ =>
+      printMessageAndPos(m.contained.msg, m.pos)
+  }
+
+  def displayPrompt(): Unit = {
+    writer.print("\na)bort, s)tack, r)esume: ")
+    writer.flush()
+    if (reader != null) {
+      val response = reader.read().asInstanceOf[Char].toLower
+      if (response == 'a' || response == 's') {
+        Thread.dumpStack()
+        if (response == 'a')
+          sys.exit(1)
+      }
+      writer.print("\n")
+      writer.flush()
+    }
+  }
+
+  override def flush()(implicit ctx: Context): Unit = { writer.flush() }
+}