Introduce -Yreporter

Author: som-snytt

compiler/src/dotty/tools/dotc/Driver.scala

@@ -84,17 +84,26 @@ class Driver {
     MacroClassLoader.init(ictx)
     Positioned.init(using ictx)
 
-    inContext(ictx) {
+    inContext(ictx):
       if !ctx.settings.XdropComments.value || ctx.settings.XreadComments.value then
         ictx.setProperty(ContextDoc, new ContextDocstrings)
       val fileNamesOrNone = command.checkUsage(summary, sourcesRequired)(using ctx.settings)(using ctx.settingsState)
       fileNamesOrNone.map: fileNames =>
         val files = fileNames.map(ctx.getFile)
         (files, fromTastySetup(files))
       .tap: _ =>
-        if ctx.settings.YnoReporter.value then
-          ictx.setReporter(Reporter.SilentReporter())
-    }
+        if !ctx.settings.Yreporter.isDefault then
+          ctx.settings.Yreporter.value match
+          case "help" =>
+          case reporterClassName =>
+            try
+              Class.forName(reporterClassName).getDeclaredConstructor().newInstance() match
+              case userReporter: Reporter =>
+                ictx.setReporter(userReporter)
+              case badReporter => report.error:
+                em"Not a reporter: ${ctx.settings.Yreporter.value}"
+            catch case e: ReflectiveOperationException => report.error:
+              em"Could not create reporter ${ctx.settings.Yreporter.value}: ${e}"
   }
 
   /** Setup extra classpath of tasty and jar files */

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

@@ -397,7 +397,7 @@ private sealed trait YSettings:
   val YdisableFlatCpCaching: Setting[Boolean] = BooleanSetting(ForkSetting, "YdisableFlatCpCaching", "Do not cache flat classpath representation of classpath elements from jars across compiler instances.")
   val YnoStdlibPatches: Setting[Boolean] = BooleanSetting(ForkSetting, "Yno-stdlib-patches", "Do not patch stdlib files (temporary and only to be used for the stdlib migration)", false)
 
-  val YnoReporter: Setting[Boolean] = BooleanSetting(ForkSetting, "Yno-reporter", "Diagnostics are silently consumed")
+  val Yreporter: Setting[String] = StringSetting(ForkSetting, name = "Yreporter", helpArg = "<class>", descr = "Specify a dotty.tools.dotc.reporting.Reporter", default = "dotty.tools.dotc.reporting.ConsoleReporter")
 
   val Yscala2Unpickler: Setting[String] = StringSetting(ForkSetting, "Yscala2-unpickler", "", "Control where we may get Scala 2 symbols from. This is either \"always\", \"never\", or a classpath.", "always")
 

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

@@ -30,7 +30,7 @@ object Reporter {
     override def report(dia: Diagnostic)(using Context): Unit = ()
   }
 
-  /** A reporter for -Yno-reporter [sic] */
+  /** A silent reporter for testing */
   class SilentReporter extends Reporter:
     def doReport(dia: Diagnostic)(using Context): Unit = ()
 

compiler/test/dotty/tools/dotc/semanticdb/SemanticdbTests.scala

@@ -144,7 +144,7 @@ class SemanticdbTests:
       "-Xignore-scala2-macros",
       "-usejavacp",
       "-Wunused:all",
-      "-Yno-reporter",
+      "-Yreporter:dotty.tools.dotc.reporting.Reporter$SilentReporter",
     ) ++ inputFiles().map(_.toString)
     val exit = Main.process(args)
     assertFalse(s"dotc errors: ${exit.errorCount}", exit.hasErrors)