From 6b8fbba1262cabf884c53e5a8ce8b4e48d3df51e Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 18 Dec 2023 10:17:11 +0100
Subject: [PATCH] Revert "Move faking errors to HideNonSensicalMessages"

This reverts commit 4fb8e7c9b1844085325876b4c2db7f5a517be691.
---
 .../reporting/HideNonSensicalMessages.scala   | 13 +------------
 .../dotty/tools/dotc/reporting/Reporter.scala | 19 ++++++++++++++++---
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/reporting/HideNonSensicalMessages.scala b/compiler/src/dotty/tools/dotc/reporting/HideNonSensicalMessages.scala
index 50b89d9fb393..5910d9b4d656 100644
--- a/compiler/src/dotty/tools/dotc/reporting/HideNonSensicalMessages.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/HideNonSensicalMessages.scala
@@ -13,18 +13,7 @@ trait HideNonSensicalMessages extends Reporter {
    */
   override def isHidden(dia: Diagnostic)(using Context): Boolean =
     super.isHidden(dia) || {
-        (if !errorsReported && dia.isInstanceOf[Diagnostic.Error] then
-          // Bump up errorCount so hasErrors is true while forcing the message.
-          // We use errorsReported as a predicate for broken code.
-          // So now any forcing won't cause, for instance,
-          // assertion errors and thus compiler crashes.
-          // Some messages, once forced, run more code
-          // to generate useful hints for the user.
-          try
-            _errorCount += 1
-            dia.msg.isNonSensical
-          finally _errorCount -= 1 // decrease rather than reset the value so we only ever decrease by 1
-        else dia.msg.isNonSensical) &&
+        dia.msg.isNonSensical &&
         hasErrors && // if there are no errors yet, report even if diagnostic is non-sensical
         !ctx.settings.YshowSuppressedErrors.value
     }
diff --git a/compiler/src/dotty/tools/dotc/reporting/Reporter.scala b/compiler/src/dotty/tools/dotc/reporting/Reporter.scala
index c24e8ba4f122..b3e54d2e6734 100644
--- a/compiler/src/dotty/tools/dotc/reporting/Reporter.scala
+++ b/compiler/src/dotty/tools/dotc/reporting/Reporter.scala
@@ -92,8 +92,8 @@ abstract class Reporter extends interfaces.ReporterResult {
 
   private def isIncompleteChecking = incompleteHandler ne defaultIncompleteHandler
 
-  protected var _errorCount = 0
-  protected var _warningCount = 0
+  private var _errorCount = 0
+  private var _warningCount = 0
 
   /** The number of errors reported by this reporter (ignoring outer reporters) */
   def errorCount: Int = _errorCount
@@ -154,7 +154,20 @@ abstract class Reporter extends interfaces.ReporterResult {
       val key = w.enablingOption.name
       addUnreported(key, 1)
     case _                                                  =>
-      if !isHidden(dia) then // avoid isHidden test for summarized warnings so that message is not forced
+      val hide = if !errorsReported && dia.isInstanceOf[Error] then
+        // We bump up errorCount so errorsReported is true while executing isHidden.
+        // We use errorsReported as a predicate for broken code.
+        // So now any code `isHidden` runs won't cause, for instance,
+        // assertion errors and thus compiler crashes.
+        // This normally amounts to forcing the message, which might run more code
+        // to generate useful hints for the user.
+        try
+          _errorCount += 1
+          isHidden(dia)
+        finally
+          _errorCount -= 1 // decrease rather than set back to `oldErrorCount` so we only ever decrease by 1
+      else isHidden(dia)
+      if !hide then // avoid isHidden test for summarized warnings so that message is not forced
         markReported(dia)
         withMode(Mode.Printing)(doReport(dia))
         dia match {