Refactor settings & improve dx

compiler/src/dotty/tools/backend/jvm/BackendUtils.scala

@@ -20,24 +20,7 @@ class BackendUtils(val postProcessor: PostProcessor) {
   import bTypes.*
   import coreBTypes.jliLambdaMetaFactoryAltMetafactoryHandle
 
-  // Keep synchronized with `minTargetVersion` and `maxTargetVersion` in ScalaSettings
-  lazy val classfileVersion: Int = compilerSettings.target match {
-    case "8"  => asm.Opcodes.V1_8
-    case "9"  => asm.Opcodes.V9
-    case "10" => asm.Opcodes.V10
-    case "11" => asm.Opcodes.V11
-    case "12" => asm.Opcodes.V12
-    case "13" => asm.Opcodes.V13
-    case "14" => asm.Opcodes.V14
-    case "15" => asm.Opcodes.V15
-    case "16" => asm.Opcodes.V16
-    case "17" => asm.Opcodes.V17
-    case "18" => asm.Opcodes.V18
-    case "19" => asm.Opcodes.V19
-    case "20" => asm.Opcodes.V20
-    case "21" => asm.Opcodes.V21
-    case "22" => asm.Opcodes.V22
-  }
+  lazy val classfileVersion: Int = BackendUtils.classfileVersionMap(compilerSettings.target.toInt)
 
   lazy val extraProc: Int = {
     import GenBCodeOps.addFlagIf
@@ -184,3 +167,23 @@ class BackendUtils(val postProcessor: PostProcessor) {
     }
   }
 }
+
+object BackendUtils {
+  lazy val classfileVersionMap: Map[Int, Int] = Map(
+    8 -> asm.Opcodes.V1_8,
+    9 -> asm.Opcodes.V9,
+    10 -> asm.Opcodes.V10,
+    11 -> asm.Opcodes.V11,
+    12 -> asm.Opcodes.V12,
+    13 -> asm.Opcodes.V13,
+    14 -> asm.Opcodes.V14,
+    15 -> asm.Opcodes.V15,
+    16 -> asm.Opcodes.V16,
+    17 -> asm.Opcodes.V17,
+    18 -> asm.Opcodes.V18,
+    19 -> asm.Opcodes.V19,
+    20 -> asm.Opcodes.V20,
+    21 -> asm.Opcodes.V21,
+    22 -> asm.Opcodes.V22,
+  )
+}

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

@@ -86,7 +86,7 @@ trait CliCommand:
   protected def isVerbose(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
     s.name.startsWith("-V") && s.name != "-V"
   protected def isWarning(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
-    s.name.startsWith("-W") && s.name != "-W" || s.name == "-Xlint"
+    s.name.startsWith("-W") && s.name != "-W"
   protected def isAdvanced(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =
     s.name.startsWith("-X") && s.name != "-X"
   protected def isPrivate(s: Setting[?])(using settings: ConcreteSettings)(using SettingsState): Boolean =

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

@@ -7,7 +7,7 @@ import core.Contexts.*
 abstract class CompilerCommand extends CliCommand:
   type ConcreteSettings = ScalaSettings
 
-  final def helpMsg(using settings: ScalaSettings)(using SettingsState, Context): String =
+  final def helpMsg(using settings: ConcreteSettings)(using SettingsState, Context): String =
     settings.allSettings.find(isHelping) match
       case Some(s) => s.description
       case _ =>
@@ -20,7 +20,7 @@ abstract class CompilerCommand extends CliCommand:
         else if (settings.XshowPhases.value) phasesMessage
         else ""
 
-  final def isHelpFlag(using settings: ScalaSettings)(using SettingsState): Boolean =
+  final def isHelpFlag(using settings: ConcreteSettings)(using SettingsState): Boolean =
     import settings.*
     val flags = Set(help, Vhelp,  Whelp, Xhelp, Yhelp, showPlugins, XshowPhases)
     flags.exists(_.value) || allSettings.exists(isHelping)

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

@@ -0,0 +1,41 @@
+package dotty.tools.dotc
+package config
+
+import dotty.tools.backend.jvm.BackendUtils.classfileVersionMap
+import dotty.tools.io.{AbstractFile, Directory, JDK9Reflectors, PlainDirectory, NoAbstractFile}
+import scala.language.unsafeNulls
+
+object ScalaSettingsProperties:
+
+  private lazy val minTargetVersion = classfileVersionMap.keysIterator.min
+  private lazy val maxTargetVersion = classfileVersionMap.keysIterator.max
+
+  def supportedTargetVersions: List[String] =
+    (minTargetVersion to maxTargetVersion).toList.map(_.toString)
+
+  def supportedReleaseVersions: List[String] =
+    if scala.util.Properties.isJavaAtLeast("9") then
+      val jdkVersion = JDK9Reflectors.runtimeVersionMajor(JDK9Reflectors.runtimeVersion()).intValue()
+      val maxVersion = Math.min(jdkVersion, maxTargetVersion)
+      (minTargetVersion to maxVersion).toList.map(_.toString)
+    else List(minTargetVersion).map(_.toString)
+
+  def supportedScalaReleaseVersions: List[String] =
+    ScalaRelease.values.toList.map(_.show)
+
+  def supportedSourceVersions: List[String] =
+    SourceVersion.values.toList.map(_.toString)
+
+  def defaultClasspath: String = sys.env.getOrElse("CLASSPATH", ".")
+
+  def defaultPageWidth: Int = {
+    val defaultWidth = 80
+    val columnsVar = System.getenv("COLUMNS")
+    if columnsVar != null then columnsVar.toInt
+    else if Properties.isWin then
+      val ansiconVar = System.getenv("ANSICON") // eg. "142x32766 (142x26)"
+      if ansiconVar != null && ansiconVar.matches("[0-9]+x.*") then
+        ansiconVar.substring(0, ansiconVar.indexOf("x")).toInt
+      else defaultWidth
+    else defaultWidth
+  }