Relax nullability checks on FlexibleTypes

compiler/src/dotty/tools/dotc/cc/CaptureSet.scala

@@ -949,7 +949,7 @@ object CaptureSet:
      *  is not derived from some other variable.
      */
     protected def ids(using Context): String =
-      def descr = getClass.getSimpleName.nn.take(1)
+      def descr = getClass.getSimpleName.take(1)
       val trail = this.match
         case dv: DerivedVar =>
           def summary = if ctx.settings.YccVerbose.value then dv.summarize else descr

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

@@ -47,7 +47,7 @@ object NullOpsDecorator:
 
     /** Is self (after widening and dealiasing) a type of the form `T | Null`? */
     def isNullableUnion(using Context): Boolean = {
-      val stripped = self.stripNull()
+      val stripped = self.stripNull(stripFlexibleTypes = false)
       stripped ne self
     }
   end extension

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

@@ -322,7 +322,7 @@ object SymbolLoaders {
           val fullName = pkg.name
           val name =
             if (packageName.isEmpty) fullName
-            else fullName.substring(packageName.length + 1).nn
+            else fullName.substring(packageName.length + 1)
 
           enterPackage(root.symbol, name.toTermName,
             (module, modcls) => new PackageLoader(module, classPath))

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

@@ -3376,12 +3376,12 @@ object TypeComparer {
   }
 
   private[core] def show(res: Any)(using Context): String =
-    if ctx.settings.YexplainLowlevel.value then String.valueOf(res).nn
+    if ctx.settings.YexplainLowlevel.value then String.valueOf(res)
     else res match
       case ClassInfo(_, cls, _, _, _) => cls.showLocated
       case bounds: TypeBounds => i"type bounds [$bounds]"
       case res: printing.Showable => res.show
-      case _ => String.valueOf(res).nn
+      case _ => String.valueOf(res)
 
   /** The approximation state indicates how the pair of types currently compared
    *  relates to the types compared originally.

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

@@ -382,7 +382,7 @@ object Types extends TypeUtils {
     /** Is this type guaranteed not to have `null` as a value? */
     final def isNotNull(using Context): Boolean = this match {
       case tp: ConstantType => tp.value.value != null
-      case tp: FlexibleType => false
+      case tp: FlexibleType => true
       case tp: ClassInfo => !tp.cls.isNullableClass && !tp.isNothingType
       case tp: AppliedType => tp.superType.isNotNull
       case tp: TypeBounds => tp.hi.isNotNull

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

@@ -1218,7 +1218,7 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
     }
     catch {
       case ex: FromDigitsException =>
-        report.error(ex.getMessage.nn, tree.srcPos)
+        report.error(ex.getMessage, tree.srcPos)
         tree.kind match {
           case Whole(_) => lit(0)
           case _ => lit(0.0)

library/src/scala/reflect/Selectable.scala

@@ -23,7 +23,7 @@ trait Selectable extends scala.Selectable:
   final def selectDynamic(name: String): Any =
     val rcls = selectedValue.getClass
     try
-      val fld = rcls.getField(NameTransformer.encode(name)).nn
+      val fld = rcls.getField(NameTransformer.encode(name))
       ensureAccessible(fld)
       fld.get(selectedValue)
     catch case ex: NoSuchFieldException =>
@@ -37,7 +37,7 @@ trait Selectable extends scala.Selectable:
    */
   final def applyDynamic(name: String, paramTypes: Class[?]*)(args: Any*): Any =
     val rcls = selectedValue.getClass
-    val mth = rcls.getMethod(NameTransformer.encode(name), paramTypes*).nn
+    val mth = rcls.getMethod(NameTransformer.encode(name), paramTypes*)
     ensureAccessible(mth)
     mth.invoke(selectedValue, args.asInstanceOf[Seq[AnyRef]]*)
 

library/src/scala/util/FromDigits.scala

@@ -154,7 +154,7 @@ object FromDigits {
         case ex: NumberFormatException => throw MalformedNumber()
       }
     if (x.isInfinite) throw NumberTooLarge()
-    if (x == 0.0d && !zeroFloat.pattern.matcher(digits).nn.matches) throw NumberTooSmall()
+    if (x == 0.0d && !zeroFloat.pattern.matcher(digits).matches) throw NumberTooSmall()
     x
   }
 

presentation-compiler/src/main/dotty/tools/pc/AutoImports.scala

@@ -23,7 +23,7 @@ object AutoImports:
     def renameConfigMap(config: PresentationCompilerConfig)(using
         Context
     ): Map[Symbol, String] =
-      config.symbolPrefixes().nn.asScala.flatMap { (from, to) =>
+      config.symbolPrefixes().asScala.flatMap { (from, to) =>
         val pkg = SemanticdbSymbols.inverseSemanticdbSymbol(from)
         val rename = to.stripSuffix(".").stripSuffix("#")
         List(pkg, pkg.map(_.moduleClass)).flatten
@@ -253,7 +253,7 @@ object AutoImports:
         // see WorksheetProvider.worksheetScala3AdjustmentsForPC
         val indent =
           if pos.source.path.isWorksheet &&
-            editPos.getStart().nn.getCharacter() == 0
+            editPos.getStart().getCharacter() == 0
           then indent0.drop(2)
           else indent0
         val topPadding =

presentation-compiler/src/main/dotty/tools/pc/AutoImportsProvider.scala

@@ -30,8 +30,8 @@ final class AutoImportsProvider(
 )(using ReportContext):
 
   def autoImports(isExtension: Boolean): List[AutoImportsResult] =
-    val uri = params.uri().nn
-    val text = params.text().nn
+    val uri = params.uri()
+    val text = params.text()
     val filePath = Paths.get(uri)
     driver.run(uri, SourceFile.virtual(filePath.toString, text))
 

presentation-compiler/src/main/dotty/tools/pc/CompilerSearchVisitor.scala

@@ -19,7 +19,7 @@ class CompilerSearchVisitor(
 )(using ctx: Context, reports: ReportContext)
     extends SymbolSearchVisitor:
 
-  val logger: Logger = Logger.getLogger(classOf[CompilerSearchVisitor].getName()).nn
+  val logger: Logger = Logger.getLogger(classOf[CompilerSearchVisitor].getName())
 
   private def isAccessibleImplicitClass(sym: Symbol) =
     val owner = sym.maybeOwner
@@ -77,7 +77,7 @@ class CompilerSearchVisitor(
       .split("\\$")
 
     val added =
-      try toSymbols(pkg, innerPath.nn.toList.map(_.nn)).filter(visitSymbol)
+      try toSymbols(pkg, innerPath.toList).filter(visitSymbol)
       catch
         case NonFatal(e) =>
           logger.log(Level.WARNING, e.getMessage(), e)

presentation-compiler/src/main/dotty/tools/pc/CompletionItemResolver.scala

@@ -50,7 +50,7 @@ object CompletionItemResolver extends ItemResolver:
       Context
   ): String =
     def docs(gsym: Symbol): String =
-      search.symbolDocumentation(gsym).fold("")(_.docstring().nn)
+      search.symbolDocumentation(gsym).fold("")(_.docstring())
     val gsymDoc = docs(gsym)
     def keyword(gsym: Symbol): String =
       if gsym.isClass then "class"

presentation-compiler/src/main/dotty/tools/pc/ConvertToNamedArgumentsProvider.scala

@@ -23,8 +23,8 @@ final class ConvertToNamedArgumentsProvider(
 ):
 
   def convertToNamedArguments: Either[String, List[l.TextEdit]] =
-    val uri = params.uri().nn
-    val text = params.text().nn
+    val uri = params.uri()
+    val text = params.text()
     val filePath = Paths.get(uri)
     driver.run(uri, SourceFile.virtual(filePath.toString, text))
 

presentation-compiler/src/main/dotty/tools/pc/DiagnosticProvider.scala

@@ -18,7 +18,7 @@ class DiagnosticProvider(driver: InteractiveDriver, params: VirtualFileParams):
 
   def diagnostics(): List[lsp4j.Diagnostic] =
     if params.shouldReturnDiagnostics then
-      val diags = driver.run(params.uri().nn, params.text().nn)
+      val diags = driver.run(params.uri(), params.text())
       given Context = driver.currentCtx
       diags.flatMap(toLsp)
     else Nil

presentation-compiler/src/main/dotty/tools/pc/ExtractMethodProvider.scala

@@ -39,8 +39,8 @@ final class ExtractMethodProvider(
     extends ExtractMethodUtils:
 
   def extractMethod(): List[TextEdit] =
-    val text = range.text().nn
-    val uri = range.uri().nn
+    val text = range.text()
+    val uri = range.uri()
     val filePath = Paths.get(uri)
     val source = SourceFile.virtual(filePath.toString, text)
     driver.run(uri, source)

presentation-compiler/src/main/dotty/tools/pc/HoverProvider.scala

@@ -37,8 +37,8 @@ object HoverProvider:
       search: SymbolSearch,
       contentType: ContentType
   )(implicit reportContext: ReportContext): ju.Optional[HoverSignature] =
-    val uri = params.uri().nn
-    val text = params.text().nn
+    val uri = params.uri()
+    val text = params.text()
     val sourceFile = SourceFile.virtual(uri, text)
     driver.run(uri, sourceFile)
     val unit = driver.compilationUnits.get(uri)
@@ -90,7 +90,7 @@ object HoverProvider:
         )
       end report
       reportContext.unsanitized.create(() => report, /*ifVerbose =*/ true)
-      ju.Optional.empty().nn
+      ju.Optional.empty()
     else
       val skipCheckOnName =
         !pos.isPoint // don't check isHoveringOnName for RangeHover
@@ -158,9 +158,9 @@ object HoverProvider:
                   contextInfo = printer.getUsedRenamesInfo,
                   contentType = contentType
                 )
-              ).nn
+              )
             case _ =>
-              ju.Optional.empty().nn
+              ju.Optional.empty()
           end match
         case (_, tpe, Some(namedTupleArg)) :: _ =>
           val exprTpw = tpe.widenTermRefExpr.deepDealiasAndSimplify
@@ -175,8 +175,8 @@ object HoverProvider:
                   contextInfo = printer.getUsedRenamesInfo,
                   contentType = contentType
                 )
-              ).nn
-            case _ => ju.Optional.empty().nn
+              )
+            case _ => ju.Optional.empty()
       end match
     end if
   end hover
@@ -238,7 +238,7 @@ object HoverProvider:
 
       refTpe.flatMap(findRefinement).headOption.asJava
     case _ =>
-      ju.Optional.empty().nn
+      ju.Optional.empty()
 
 end HoverProvider