path: root/src/dotty/tools/dotc/reporting/Diagnostic.scala

package dotty.tools
package dotc
package reporting

import util.SourcePosition

import java.util.Optional

object Diagnostic {
  val nonSensicalStartTag = "<nonsensical>"
  val nonSensicalEndTag = "</nonsensical>"
}

class Diagnostic(msgFn: => String, val pos: SourcePosition, val level: Int, val kind: String)
    extends Exception with interfaces.Diagnostic {
  import Diagnostic._
  private var myMsg: String = null
  private var myIsNonSensical: Boolean = false

  override def position: Optional[interfaces.SourcePosition] =
    if (pos.exists && pos.source.exists) Optional.of(pos) else Optional.empty()

  /** The message to report */
  def message: 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 = { message; myIsNonSensical }

  override def toString = s"$getClass at $pos: $message"
  override def getMessage() = message
}