enable filtering warnings by their ErrorMessageID name

Author: lrytz

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -152,6 +152,9 @@ private sealed trait WarningSettings:
          |  - Message id: id=E129
          |    The message id is printed with the warning.
          |
+         |  - Message name: name=PureExpressionInStatementPosition
+         |    The message name is printed with the warning in verbose warning mode.
+         |
          |In verbose warning mode the compiler prints matching filters for warnings.
          |Verbose mode can be enabled globally using `-Wconf:any:verbose`, or locally
          |using the @nowarn annotation (example: `@nowarn("v") def test = try 1`).

compiler/src/dotty/tools/dotc/reporting/MessageRendering.scala

@@ -155,6 +155,7 @@ trait MessageRendering {
       sb.append(EOL).append("Matching filters for @nowarn or -Wconf:")
       if (hasId)
         sb.append(EOL).append("  - id=E").append(msg.errorId.errorNumber)
+        sb.append(EOL).append("  - name=").append(msg.errorId.productPrefix.stripSuffix("ID"))
       if (category.nonEmpty)
         sb.append(EOL).append("  - cat=").append(category)
 

compiler/src/dotty/tools/dotc/reporting/WConf.scala

@@ -69,6 +69,10 @@ object WConf:
             Left(s"unknonw error message id: E$n")
         case _ =>
           Left(s"invalid error message id: $conf")
+      case "name" =>
+        try Right(MessageID(ErrorMessageID.valueOf(conf + "ID")))
+        catch case _: IllegalArgumentException => Left(s"unknown error message name: $conf")
+
       case "cat" => conf match
         case "deprecation" => Right(Deprecated)
         case "feature"     => Right(Feature)