ConsoleReporter: handling of non-sensical messages is now reusable

This is now handled by a separate trait HideNonSensicalMessages that can
be mixed in, similar to UniqueMessagePositions. This way we'll be able
to reuse this functionality for other kind of Reporters.

This also means that we don't need `doReport` to return a Boolean
anymore, so we change it to return a Unit as it did before
065a002

Author: smarter

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

@@ -16,7 +16,7 @@ import scala.reflect.internal.util._
 class ConsoleReporter(
     reader: BufferedReader = Console.in,
     writer: PrintWriter = new PrintWriter(Console.err, true))
-  extends Reporter with UniqueMessagePositions {
+  extends Reporter with UniqueMessagePositions with HideNonSensicalMessages {
 
   /** maximal number of error messages to be printed */
   protected def ErrorLimit = 100
@@ -40,24 +40,17 @@ class ConsoleReporter(
     }
   }
 
-  override def doReport(d: Diagnostic)(implicit ctx: Context): Boolean = {
-    val issue =
-      !d.isNonSensical ||
-      !hasErrors || // if there are no errors yet, report even if diagnostic is non-sensical
-      ctx.settings.YshowSuppressedErrors.value
-    if (issue) d match {
-      case d: Error =>
-        printMessageAndPos(s"error: ${d.msg}", d.pos)
-        if (ctx.settings.prompt.value) displayPrompt()
-      case d: ConditionalWarning if !d.enablingOption.value =>
-      case d: MigrationWarning =>
-        printMessageAndPos(s"migration warning: ${d.msg}", d.pos)
-      case d: Warning =>
-        printMessageAndPos(s"warning: ${d.msg}", d.pos)
-      case _ =>
-        printMessageAndPos(d.msg, d.pos)
-    }
-    issue
+  override def doReport(d: Diagnostic)(implicit ctx: Context): Unit = d match {
+    case d: Error =>
+      printMessageAndPos(s"error: ${d.msg}", d.pos)
+      if (ctx.settings.prompt.value) displayPrompt()
+    case d: ConditionalWarning if !d.enablingOption.value =>
+    case d: MigrationWarning =>
+      printMessageAndPos(s"migration warning: ${d.msg}", d.pos)
+    case d: Warning =>
+      printMessageAndPos(s"warning: ${d.msg}", d.pos)
+    case _ =>
+      printMessageAndPos(d.msg, d.pos)
   }
 
   def displayPrompt(): Unit = {

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

@@ -0,0 +1,20 @@
+package dotty.tools
+package dotc
+package reporting
+
+import core.Contexts.Context
+
+/**
+ * This trait implements `isHidden` so that we avoid reporting non-sensical messages.
+ */
+trait HideNonSensicalMessages extends Reporter {
+  /** Hides non-sensical messages, unless we haven't reported any error yet or
+   *  `-Yshow-suppressed-errors` is set.
+   */
+  override def isHidden(d: Diagnostic)(implicit ctx: Context): Boolean =
+    super.isHidden(d) || {
+        d.isNonSensical &&
+        hasErrors && // if there are no errors yet, report even if diagnostic is non-sensical
+        !ctx.settings.YshowSuppressedErrors.value
+    }
+}

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

@@ -159,10 +159,8 @@ trait Reporting { this: Context =>
  */
 abstract class Reporter {
 
-  /** Report a diagnostic, unless it is suppressed because it is nonsensical
-   *  @return a diagnostic was reported.
-   */
-  def doReport(d: Diagnostic)(implicit ctx: Context): Boolean
+  /** Report a diagnostic */
+  def doReport(d: Diagnostic)(implicit ctx: Context): Unit
 
  /** Whether very long lines can be truncated.  This exists so important
    *  debugging information (like printing the classpath) is not rendered
@@ -203,7 +201,8 @@ abstract class Reporter {
   }
 
   def report(d: Diagnostic)(implicit ctx: Context): Unit =
-    if (!isHidden(d) && doReport(d)(ctx.addMode(Mode.Printing)))
+    if (!isHidden(d)) {
+      doReport(d)(ctx.addMode(Mode.Printing))
       d match {
         case d: ConditionalWarning if !d.enablingOption.value => unreportedWarnings(d.enablingOption.name) += 1
         case d: Warning => warningCount += 1
@@ -213,6 +212,7 @@ abstract class Reporter {
         case d: Info => // nothing to do here
         // match error if d is something else
       }
+    }
 
   def incomplete(d: Diagnostic)(implicit ctx: Context): Unit =
     incompleteHandler(d)(ctx)

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

@@ -14,11 +14,10 @@ class StoreReporter(outer: Reporter) extends Reporter {
 
   private var infos: mutable.ListBuffer[Diagnostic] = null
 
-  def doReport(d: Diagnostic)(implicit ctx: Context): Boolean = {
+  def doReport(d: Diagnostic)(implicit ctx: Context): Unit = {
     typr.println(s">>>> StoredError: ${d.msg}") // !!! DEBUG
     if (infos == null) infos = new mutable.ListBuffer
     infos += d
-    true
   }
 
   override def hasPending: Boolean = infos != null && {

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

@@ -11,7 +11,7 @@ import Reporter._
  * info to the underlying reporter.
  */
 class ThrowingReporter(reportInfo: Reporter) extends Reporter {
-  def doReport(d: Diagnostic)(implicit ctx: Context): Boolean = d match {
+  def doReport(d: Diagnostic)(implicit ctx: Context): Unit = d match {
     case _: Error => throw d
     case _ => reportInfo.doReport(d)
   }