Lift Scala Settings from experimental to stabilized (#20199)

Fixes: #19693

This is the tracking list from the issue and the status of migraton.
- [x] lift to `-X`
  - [x] `-Yresolve-term-conflict`
  - [x] `-YnoGenericSig`
  - [x] `-Ydumpclasses`
  - [x] `-YjarCompressionLevel`
  - [x] `-YkindProjector`
  - [x] `-YdropComments`
  - [x] `-YcookComments`
  - [x] `-YreadComments`
  - [x] `-YnoDecodeStacktraces`
  - [x] `-YnoEnrichErrorMessages`
  - [x] `-YdebugMacros`
  - [ ] `-YjavaTasty`- deprecate in 3.7.0
  - [ ] `-YjavaTastyOutput`- deprecate in 3.7.0
  - [ ] `-YallowOutlineFromTasty`- deprecate in 3.7.0
- [x] lift to `-W`
  - [x] `-Wsafe-init`
- [x] to be removed
- [x] `--Yforce-inline-while-typing` // Note: this was already removed
by
05eb7f7
- [ ] TBD
  - [ ] `-YfromTastyIgnoreList` // this flag was not decided
  - [x] `-YoutputOnlyTasty`

I suppose 2 last flags that have to be decided are maintained by
@bishabosha
Do you know their status ?

Other than that, this PR implemented a deprecation mechanism for the
future e.g.
```scala
Deprecation(
  msg = "message",
  replacedBy = Some("newMessage"),
)
```

EDIT:
As it was decided, options responsible for pipelining will be retained
until 3.7.0.
The code is commented and following PR which will deprecate them will be
created after merging this one.

EDIT2:
`-Xlint` is a very problematic flag. It was added into the compiler in
3.4 bypassing argument verification. Then in the future, when it was
deprecated in favour of `-Wshadow` we couldn't exactly map them 1-1, and
it was deprecated in following way:
- Scala 2: `-Xlint` is valid flag,
- Scala pre 3.4: `-Xlint` was skipped as it was not implemented,
- Scala post 3.4 pre flag refactor: `-Xlint` was implemented allowing
for `all`, `private-shadow` and `type-parameter-shadow` options. It also
bypassed argument verification allowing standalone `-Xlint` to be
ignored, not reported as error,
- Scala post 3.4 post flag refactor: This flag was then deprecated in
favour of `-Wshadow`. We didn't want to commit this mistake again and
allow standalone `-Wshadow` thus when it was deprecated, we didn't
handle it as we should (deprecated option should trigger replacement
when possible).

That's why I'm retaining the previous behaviour of `-Xlint`. It will be
removed in the future versions as it is already deprecated.

community-build/src/scala/dotty/communitybuild/projects.scala

@@ -149,7 +149,7 @@ final case class SbtCommunityProject(
 object SbtCommunityProject:
   def scalacOptions = List(
     "-Xcheck-macros",
-    "-Ysafe-init",
+    "-Wsafe-init",
   )
 
 object projects:
@@ -362,7 +362,7 @@ object projects:
     project = "shapeless-3",
     sbtTestCommand = "testJVM; testJS",
     sbtDocCommand = forceDoc("typeable", "deriving"),
-    scalacOptions = "-source" :: "3.3" :: SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"), // due to -Xfatal-warnings
+    scalacOptions = "-source" :: "3.3" :: SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"), // due to -Xfatal-warnings
   )
 
   lazy val xmlInterpolator = SbtCommunityProject(
@@ -429,7 +429,7 @@ object projects:
     sbtTestCommand   = "unitTests/test",
     // Adds <empty> package
     sbtDocCommand   = "coreJVM/doc",
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"),
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"),
     dependencies = List(munit, scodecBits),
   )
 
@@ -510,7 +510,7 @@ object projects:
     project = "discipline",
     sbtTestCommand = "coreJVM/test;coreJS/test",
     sbtPublishCommand = "set every credentials := Nil;coreJVM/publishLocal;coreJS/publishLocal",
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"),
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"),
     dependencies = List(scalacheck)
   )
 
@@ -526,7 +526,7 @@ object projects:
     sbtTestCommand = "test",
     sbtPublishCommand = "coreJVM/publishLocal;coreJS/publishLocal",
     dependencies = List(discipline),
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init")
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init")
   )
 
   lazy val simulacrumScalafixAnnotations = SbtCommunityProject(
@@ -540,8 +540,7 @@ object projects:
     sbtTestCommand = "set Global/scalaJSStage := FastOptStage;rootJVM/test;rootJS/test",
     sbtPublishCommand = "rootJVM/publishLocal;rootJS/publishLocal",
     dependencies = List(discipline, disciplineMunit, scalacheck, simulacrumScalafixAnnotations),
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init") // disable -Ysafe-init, due to -Xfatal-warning
-
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init") // disable -Ysafe-init or -Wsafe-init, due to -Xfatal-warning
   )
 
   lazy val catsMtl = SbtCommunityProject(
@@ -656,7 +655,7 @@ object projects:
       """set actorTests/Compile/scalacOptions -= "-Xfatal-warnings"""",
       "akka-actor-tests/Test/compile",
     ).mkString("; "),
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"),
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"),
     dependencies = List(scalatest, scalatestplusJunit, scalatestplusScalacheck)
   )
 
@@ -707,7 +706,7 @@ object projects:
     project = "fs2",
     sbtTestCommand = "coreJVM/test; coreJS/test",  // io/test requires JDK9+
     sbtPublishCommand = "coreJVM/publishLocal; coreJS/publishLocal",
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"),
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"),
     dependencies = List(cats, catsEffect3, munitCatsEffect, scalacheckEffect, scodecBits)
   )
 
@@ -744,7 +743,7 @@ object projects:
     project = "http4s",
     sbtTestCommand = """set ThisBuild / tlFatalWarnings := false; rootJVM/test""",
     sbtPublishCommand = "publishLocal",
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Ysafe-init"),
+    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Wsafe-init"),
     dependencies = List(cats, catsEffect3, fs2, disciplineMunit, scalacheckEffect)
   )
 

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

@@ -823,7 +823,7 @@ trait BCodeHelpers extends BCodeIdiomatic {
     // without it.  This is particularly bad because the availability of
     // generic information could disappear as a consequence of a seemingly
     // unrelated change.
-      ctx.base.settings.YnoGenericSig.value
+      ctx.base.settings.XnoGenericSig.value
     || sym.is(Artifact)
     || sym.isAllOf(LiftedMethod)
     || sym.is(Bridge)

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

@@ -121,12 +121,14 @@ object PostProcessorFrontendAccess {
           case (None, None) => "8" // least supported version by default
 
       override val debug: Boolean = ctx.debug
-      override val dumpClassesDirectory: Option[String] = s.Ydumpclasses.valueSetByUser
+      override val dumpClassesDirectory: Option[String] = s.Xdumpclasses.valueSetByUser
       override val outputDirectory: AbstractFile = s.outputDir.value
       override val mainClass: Option[String] = s.XmainClass.valueSetByUser
-      override val jarCompressionLevel: Int = s.YjarCompressionLevel.value
+      override val jarCompressionLevel: Int = s.XjarCompressionLevel.value
       override val backendParallelism: Int = s.YbackendParallelism.value
       override val backendMaxWorkerQueue: Option[Int] = s.YbackendWorkerQueue.valueSetByUser
+
+      @annotation.nowarn("cat=deprecation")
       override val outputOnlyTasty: Boolean = s.YoutputOnlyTasty.value
      }
 

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

@@ -84,7 +84,7 @@ class Driver {
     Positioned.init(using ictx)
 
     inContext(ictx) {
-      if !ctx.settings.YdropComments.value || ctx.settings.YreadComments.value then
+      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 =>

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

@@ -377,7 +377,7 @@ class Run(comp: Compiler, ictx: Context) extends ImplicitRunInfo with Constraint
     runCtx.withProgressCallback: cb =>
       _progress = Progress(cb, this, fusedPhases.map(_.traversals).sum)
     val cancelAsyncTasty: () => Unit =
-      if !myAsyncTastyWritten && Phases.picklerPhase.exists && !ctx.settings.YearlyTastyOutput.isDefault then
+      if !myAsyncTastyWritten && Phases.picklerPhase.exists && !ctx.settings.XearlyTastyOutput.isDefault then
         initializeAsyncTasty()
       else () => {}
 

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

@@ -60,7 +60,8 @@ trait CliCommand:
       def defaultValue = s.default match
         case _: Int | _: String => s.default.toString
         case _ => ""
-      val info = List(shortHelp(s), if defaultValue.nonEmpty then s"Default $defaultValue" else "", if s.legalChoices.nonEmpty then s"Choices : ${s.legalChoices}" else "")
+      val deprecationMessage = s.deprecation.map(d => s"Option deprecated.\n${d.msg}").getOrElse("")
+      val info = List(deprecationMessage, shortHelp(s), if defaultValue.nonEmpty then s"Default $defaultValue" else "", if s.legalChoices.nonEmpty then s"Choices : ${s.legalChoices}" else "")
       (s.name, info.filter(_.nonEmpty).mkString("\n"))
     end help