Refactor settings & improve dx

Author: szymon-rd

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)
 
   lazy val extraProc: Int = {
     import GenBCodeOps.addFlagIf
@@ -184,3 +167,23 @@ class BackendUtils(val postProcessor: PostProcessor) {
     }
   }
 }
+
+object BackendUtils {
+  lazy val classfileVersionMap = 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/Driver.scala

@@ -10,6 +10,7 @@ import dotty.tools.io.AbstractFile
 import reporting.*
 import core.Decorators.*
 import config.Feature
+import dotty.tools.dotc.config.ScalaSettings
 
 import scala.util.control.NonFatal
 import fromtasty.{TASTYCompiler, TastyFileUtil}
@@ -199,6 +200,7 @@ class Driver {
   }
 
   def main(args: Array[String]): Unit = {
+    println("settings: " + ScalaSettings.allSettings)
     // Preload scala.util.control.NonFatal. Otherwise, when trying to catch a StackOverflowError,
     // we may try to load it but fail with another StackOverflowError and lose the original exception,
     // see <https://groups.google.com/forum/#!topic/scala-user/kte6nak-zPM>.

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

@@ -5,9 +5,9 @@ import Settings.*
 import core.Contexts.*
 
 abstract class CompilerCommand extends CliCommand:
-  type ConcreteSettings = ScalaSettings
+  type ConcreteSettings = ScalaSettings.type
 
-  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/ScalaSettings.scala

@@ -513,7 +513,7 @@ object Contexts {
       s"""Context(
          |${outersIterator.map(ctx => cinfo(using ctx)).mkString("\n\n")})""".stripMargin
 
-    def settings: ScalaSettings            = base.settings
+    def settings: ScalaSettings.type            = base.settings
     def definitions: Definitions           = base.definitions
     def platform: Platform                 = base.platform
     def pendingUnderlying: util.HashSet[Type]      = base.pendingUnderlying
@@ -861,8 +861,7 @@ object Contexts {
                        with Phases.PhasesBase
                        with Plugins {
 
-    /** The applicable settings */
-    val settings: ScalaSettings = new ScalaSettings
+    val settings: ScalaSettings.type = ScalaSettings
 
     /** The initial context */
     val initialCtx: Context = FreshContext.initial(this: @unchecked, settings)

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

@@ -17,7 +17,7 @@ class ScalaCommandTest:
   def temporaryFolder = _temporaryFolder
 
   @Test def `Simple one parameter`: Unit = inContext {
-    val settings = config.ScalaSettings()
+    val settings = config.ScalaSettings
     val args = "-cp path/to/classes1:other/path/to/classes2 files".split(" ")
     val summary = ScalacCommand.distill(args, settings)()
     given SettingsState = summary.sstate
@@ -26,7 +26,7 @@ class ScalaCommandTest:
   }
 
   @Test def `Unfold @file`: Unit = inContext {
-    val settings = config.ScalaSettings()
+    val settings = config.ScalaSettings
     val file = temporaryFolder.newFile("config")
     val writer = java.io.FileWriter(file);
     writer.write("-sourceroot myNewRoot someMoreFiles");

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -43,8 +43,8 @@ class SettingsTests {
 
   @Test def acceptUnconstrained: Unit =
     object Settings extends SettingGroup:
-      val foo = StringSetting("-foo", "foo", "Foo", "a")
-      val bar = IntSetting("-bar", "Bar", 0)
+      val foo = StringSetting("", "foo", "foo", "Foo", "a")
+      val bar = IntSetting("", "bar", "Bar", 0)
 
     val args = List("-foo", "b", "-bar", "1")
     val summary = Settings.processArguments(args, true)
@@ -72,7 +72,7 @@ class SettingsTests {
 
   @Test def `dont crash on many options`: Unit =
     object Settings extends SettingGroup:
-      val option = BooleanSetting("-option", "Some option")
+      val option = BooleanSetting("", "-option", "Some option")
 
     val limit = 6000
     val args = List.fill(limit)("-option")
@@ -87,7 +87,7 @@ class SettingsTests {
 
   @Test def `bad option warning consumes an arg`: Unit =
     object Settings extends SettingGroup:
-      val option = BooleanSetting("-option", "Some option")
+      val option = BooleanSetting("", "-option", "Some option")
 
     val args = List("-adoption", "dogs", "cats")
     val summary = Settings.processArguments(args, processAll = true)
@@ -97,7 +97,7 @@ class SettingsTests {
 
   @Test def `bad option settings throws`: Unit =
     object Settings extends SettingGroup:
-      val option = BooleanSetting("-option", "Some option")
+      val option = BooleanSetting("", "-option", "Some option")
 
     def checkMessage(s: String): (Throwable => Boolean) = t =>
       if t.getMessage == s then true
@@ -112,12 +112,12 @@ class SettingsTests {
 
   @Test def validateChoices: Unit =
     object Settings extends SettingGroup:
-      val foo = ChoiceSetting("-foo", "foo", "Foo", List("a", "b"), "a")
-      val bar = IntChoiceSetting("-bar", "Bar", List(0, 1, 2), 0)
-      val baz = IntChoiceSetting("-baz", "Baz", 0 to 10, 10)
+      val foo = ChoiceSetting("", "-foo", "foo", "Foo", List("a", "b"), "a")
+      val bar = IntChoiceSetting("", "-bar", "Bar", List(0, 1, 2), 0)
+      val baz = IntChoiceSetting("", "-baz", "Baz", 0 to 10, 10)
 
-      val quux = ChoiceSetting("-quux", "quux", "Quux", List(), "")
-      val quuz = IntChoiceSetting("-quuz", "Quuz", List(), 0)
+      val quux = ChoiceSetting("", "-quux", "quux", "Quux", List(), "")
+      val quuz = IntChoiceSetting("", "-quuz", "Quuz", List(), 0)
 
     locally {
       val args = List("-foo", "b", "-bar", "1", "-baz", "5")
@@ -169,7 +169,7 @@ class SettingsTests {
 
   @Test def `Allow IntSetting's to be set with a colon`: Unit =
     object Settings extends SettingGroup:
-      val foo = IntSetting("-foo", "foo", 80)
+      val foo = IntSetting("", "-foo", "foo", 80)
     import Settings._
 
     val args = List("-foo:100")
@@ -181,10 +181,10 @@ class SettingsTests {
 
   @Test def `Set BooleanSettings correctly`: Unit =
     object Settings extends SettingGroup:
-      val foo = BooleanSetting("-foo", "foo", false)
-      val bar = BooleanSetting("-bar", "bar", true)
-      val baz = BooleanSetting("-baz", "baz", false)
-      val qux = BooleanSetting("-qux", "qux", false)
+      val foo = BooleanSetting("", "-foo", "foo", false)
+      val bar = BooleanSetting("", "-bar", "bar", true)
+      val baz = BooleanSetting("", "-baz", "baz", false)
+      val qux = BooleanSetting("", "-qux", "qux", false)
     import Settings._
 
     val args = List("-foo:true", "-bar:false", "-baz", "-qux:true", "-qux:false")

compiler/test/dotty/tools/dotc/ScalaCommandTest.scala

@@ -12,7 +12,7 @@ class ScalaSettingsTests:
 
   @Test def `A setting with aliases is accepted`: Unit =
     class MySettings extends SettingGroup:
-      val classpath: Setting[String] = PathSetting("-classpath", "Specify where to find user class files.", ".", aliases = List("--class-path", "-cp"))
+      val classpath: Setting[String] = PathSetting("", "classpath", "Specify where to find user class files.", ".", aliases = List("--class-path", "-cp"))
     val settings = MySettings()
     val args = tokenize("-cp path/to/classes1:other/path/to/classes2")
     val summary = ArgsSummary(settings.defaultState, args, errors = Nil, warnings = Nil)
@@ -25,7 +25,7 @@ class ScalaSettingsTests:
 
   @Test def `A multistring setting is multivalued`: Unit =
     class SUT extends SettingGroup:
-      val language: Setting[List[String]] = MultiStringSetting("-language", "feature", "Enable one or more language features.")
+      val language: Setting[List[String]] = MultiStringSetting("", "language", "feature", "Enable one or more language features.")
     val sut  = SUT()
     val args = tokenize("-language:implicitConversions,dynamics")
     val sumy = ArgsSummary(sut.defaultState, args, errors = Nil, warnings = Nil)
@@ -39,7 +39,7 @@ class ScalaSettingsTests:
 
   @Test def `t9719 Apply -language more than once`: Unit =
     class SUT extends SettingGroup:
-      val language: Setting[List[String]] = MultiStringSetting("-language", "feature", "Enable one or more language features.")
+      val language: Setting[List[String]] = MultiStringSetting("", "language", "feature", "Enable one or more language features.")
     val sut  = SUT()
     val args = tokenize("-language:implicitConversions -language:dynamics")
     val sumy = ArgsSummary(sut.defaultState, args, errors = Nil, warnings = Nil)
@@ -53,7 +53,7 @@ class ScalaSettingsTests:
 
   @Test def `Warn if multistring element is supplied multiply`: Unit =
     class SUT extends SettingGroup:
-      val language: Setting[List[String]] = MultiStringSetting("-language", "feature", "Enable one or more language features.")
+      val language: Setting[List[String]] = MultiStringSetting("", "language", "feature", "Enable one or more language features.")
     val sut  = SUT()
     val args = tokenize("-language:dynamics -language:implicitConversions -language:dynamics")
     val sumy = ArgsSummary(sut.defaultState, args, errors = Nil, warnings = Nil)
@@ -67,7 +67,7 @@ class ScalaSettingsTests:
 
   @Test def `WConf setting is parsed`: Unit =
     import reporting.{Action, Diagnostic, NoExplanation}
-    val sets = new ScalaSettings
+    val sets = ScalaSettings
     val args = List("-Wconf:cat=deprecation:s,cat=feature:e", "-Wconf:msg=a problem\\.:s")
     val sumy = ArgsSummary(sets.defaultState, args, errors = Nil, warnings = Nil)
     val proc = sets.processArguments(sumy, processAll = true, skipped = Nil)
@@ -85,7 +85,7 @@ class ScalaSettingsTests:
 
   @Test def `i18367 rightmost WConf flags take precedence over flags to the left`: Unit =
     import reporting.{Action, Diagnostic}
-    val sets = new ScalaSettings
+    val sets = ScalaSettings
     val args = List("-Wconf:cat=deprecation:e", "-Wconf:cat=deprecation:s")
     val sumy = ArgsSummary(sets.defaultState, args, errors = Nil, warnings = Nil)
     val proc = sets.processArguments(sumy, processAll = true, skipped = Nil)