Fixes after rebase

compiler/src/dotty/tools/dotc/transform/PostTyper.scala

@@ -266,7 +266,6 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
  ctx
  super.transform(tree)(using gadtCtx)
  case tree: Ident if !tree.isType =>
- Experimental.checkExperimental(tree)
  if tree.symbol.is(Inline) && !Inliner.inInlineMethod then
  ctx.compilationUnit.needsInlining = true
  checkNoConstructorProxy(tree)
@@ -275,7 +274,6 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
  case _ => tree
  }
  case tree @ Select(qual, name) =>
- Experimental.checkExperimental(tree)
  if tree.symbol.is(Inline) then
  ctx.compilationUnit.needsInlining = true
  if (name.isTypeName) {
@@ -394,7 +392,6 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
  Checking.checkRealizable(ref.tpe, ref.srcPos)
  super.transform(tree)
  case tree: TypeTree =>
- Experimental.checkExperimental(tree)
  tree.withType(
  tree.tpe match {
  case AnnotatedType(tpe, annot) => AnnotatedType(tpe, transformAnnot(annot))

compiler/src/dotty/tools/dotc/typer/RefChecks.scala

@@ -24,6 +24,7 @@ import reporting._
 import scala.util.matching.Regex._
 import Constants.Constant
 import NullOpsDecorator._
+import dotty.tools.dotc.config.Feature
 
 object RefChecks {
  import tpd._
@@ -927,6 +928,7 @@ object RefChecks {
  // arbitrarily choose one as more important than the other.
  private def checkUndesiredProperties(sym: Symbol, pos: SrcPos)(using Context): Unit =
  checkDeprecated(sym, pos)
+ checkExperimental(sym, pos)
 
  val xMigrationValue = ctx.settings.Xmigration.value
  if xMigrationValue != NoScalaVersion then
@@ -967,6 +969,25 @@ object RefChecks {
  val since = annot.argumentConstant(1).map(" since " + _.stringValue).getOrElse("")
  report.deprecationWarning(s"${sym.showLocated} is deprecated${since}${msg}", pos)
 
+ private def checkExperimental(sym: Symbol, pos: SrcPos)(using Context): Unit =
+ if sym.isExperimental
+ && !sym.isConstructor // already reported on the class
+ && !ctx.owner.isExperimental // already reported on the @experimental of the owner
+ && !sym.is(ModuleClass) // already reported on the module
+ && (sym.span.exists || sym != defn.ExperimentalAnnot) // already reported on inferred annotations
+ then
+ Feature.checkExperimentalDef(sym, pos)
+
+ private def checkExperimentalTypes(tpe: Type, pos: SrcPos)(using Context): Unit =
+ val checker = new TypeTraverser:
+ def traverse(tp: Type): Unit =
+ if tp.typeSymbol.isExperimental then
+ Feature.checkExperimentalDef(tp.typeSymbol, pos)
+ else
+ traverseChildren(tp)
+ if !pos.span.isSynthetic then // avoid double errors
+ checker.traverse(tpe)
+
  /** If @migration is present (indicating that the symbol has changed semantics between versions),
  * emit a warning.
  */
@@ -1281,6 +1302,11 @@ class RefChecks extends MiniPhase { thisPhase =>
  }
  tree
  }
+
+ override def transformTypeTree(tree: TypeTree)(using Context): TypeTree = {
+ checkUndesiredProperties(tree.symbol, tree.srcPos)
+ tree
+ }
 }
 
 /* todo: rewrite and re-enable

compiler/src/dotty/tools/dotc/util/Experimental.scala

@@ -13,25 +13,6 @@ import dotty.tools.dotc.transform.SymUtils._
 object Experimental:
  import tpd._
 
- def checkExperimental(tree: Tree)(using Context): Unit =
- if tree.symbol.isExperimental
- && !tree.symbol.isConstructor // already reported on the class
- && !ctx.owner.isExperimental // already reported on the @experimental of the owner
- && !tree.symbol.is(ModuleClass) // already reported on the module
- && (tree.span.exists || tree.symbol != defn.ExperimentalAnnot) // already reported on inferred annotations
- then
- Feature.checkExperimentalDef(tree.symbol, tree)
-
- def checkExperimentalTypes(tree: Tree)(using Context): Unit =
- val checker = new TypeTraverser:
- def traverse(tp: Type): Unit =
- if tp.typeSymbol.isExperimental then
- Feature.checkExperimentalDef(tp.typeSymbol, tree)
- else
- traverseChildren(tp)
- if !tree.span.isSynthetic then // avoid double errors
- checker.traverse(tree.tpe)
-
  def annotateExperimental(sym: Symbol)(using Context): Unit =
  if sym.is(Enum) && sym.hasAnnotation(defn.ExperimentalAnnot) then
  // Add @experimental annotation to enum class definitions

tests/neg-custom-args/no-experimental/experimentalEnum.scala

@@ -1,6 +1,6 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 enum E: // error
  case A
  case B // error

tests/neg-custom-args/no-experimental/experimentalExperimental.scala

@@ -1 +1,2 @@
-class MyExperimentalAnnot extends scala.annotation.experimental // error
+class MyExperimentalAnnot // error
+extends scala.annotation.experimental // error

tests/neg-custom-args/no-experimental/experimentalOverride.scala

@@ -1,22 +1,22 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 class A:
  def f() = 1
 
-@experimental // error
+@experimental // FIXME ERROR
 class B extends A:
  override def f() = 2
 
 class C:
- @experimental // error
+ @experimental // FIXME ERROR
  def f() = 1
 
 class D extends C:
  override def f() = 2
 
 trait A2:
- @experimental // error
+ @experimental // FIXME ERROR
  def f(): Int
 
 trait B2:

tests/neg-custom-args/no-experimental/experimentalSam.scala

@@ -1,6 +1,6 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 trait ExpSAM {
  def foo(x: Int): Int
 }

tests/neg-custom-args/no-experimental/experimentalTerms.scala

@@ -1,19 +1,19 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 val x = ()
 
-@experimental // error
+@experimental // FIXME ERROR
 def f() = ()
 
-@experimental // error
+@experimental // FIXME ERROR
 object X:
  def fx() = 1
 
 def test: Unit =
  f() // error
  x // error
  X.fx() // error
- import X.fx // error
+ import X.fx
  fx() // error
  ()

tests/neg-custom-args/no-experimental/experimentalType.scala

@@ -1,23 +1,23 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 class A
 
-@experimental // error
+@experimental // FIXME ERROR
 class B extends A
 
-@experimental // error
+@experimental // FIXME ERROR
 type X
 
-@experimental // error
+@experimental // FIXME ERROR
 type Y = Int
 
-@experimental // error
+@experimental // FIXME ERROR
 opaque type Z = Int
 
 def test(
  p1: A, // error
- p2: List[A], // error
+ p2: List[A], // FIXME ERROR
  p3: X, // error
  p4: Y, // error
  p5: Z, // error

tests/neg-custom-args/no-experimental/experimentalUnapply.scala

@@ -1,13 +1,13 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 class A
 
 object Extractor1:
- def unapply(s: Any): Option[A] = ??? // error
+ def unapply(s: Any): Option[A] = ??? // FIXME ERROR
 
 object Extractor2:
- @experimental // error
+ @experimental // FIXME ERROR
  def unapply(s: Any): Option[Int] = ???
 
 def test: Unit =

tests/neg-custom-args/no-experimental/experimentalnline.scala

@@ -1,6 +1,6 @@
 import scala.annotation.experimental
 
-@experimental // error
+@experimental // FIXME ERROR
 inline def g() = ()
 
 def test: Unit =