Refactor Diagnostic

Break it out from Reporter and eliminate all dependencies
to Context. This is done so that Diagnostics can be part
of a public and minimal compiler API.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/dotty/tools/dotc/reporting/Diagnostic.scala b/src/dotty/tools/dotc/reporting/Diagnostic.scala
new file mode 100644
index 000000000..c57be3d26
--- /dev/null
+++ b/src/dotty/tools/dotc/reporting/Diagnostic.scala
@@ -0,0 +1,47 @@
+package dotty.tools
+package dotc
+package reporting
+
+import util.SourcePosition
+
+object Diagnostic {
+
+  // Error levels
+  val ERROR = 2
+  val WARNING = 1
+  val INFO = 0
+
+  val nonSensicalStartTag = "<nonsensical>"
+  val nonSensicalEndTag = "</nonsensical>"
+}
+
+class Diagnostic(msgFn: => String, val pos: SourcePosition, val level: Int) extends Exception {
+  import Diagnostic._
+  private var myMsg: String = null
+  private var myIsNonSensical: Boolean = false
+
+  /** The message to report */
+  def msg: String = {
+    if (myMsg == null) {
+      myMsg = msgFn
+      if (myMsg.contains(nonSensicalStartTag)) {
+        myIsNonSensical = true
+        // myMsg might be composed of several d"..." invocations -> nested nonsensical tags possible
+        myMsg = myMsg.replaceAllLiterally(nonSensicalStartTag, "").replaceAllLiterally(nonSensicalEndTag, "")
+      }
+    }
+    myMsg
+  }
+
+  /** A message is non-sensical if it contains references to <nonsensical> tags.
+   *  Such tags are inserted by the error diagnostic framework if a message
+   *  contains references to internally generated error types. Normally we
+   *  want to suppress error messages referring to types like this because
+   *  they look weird and are normally follow-up errors to something that
+   *  was diagnosed before.
+   */
+  def isNonSensical = { msg; myIsNonSensical }
+
+  override def toString = s"$getClass at $pos: $msg"
+  override def getMessage() = msg
+}