Remove some unsafe nulls

Author: SuperCl4sh

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

@@ -2,8 +2,6 @@ package dotty.tools
 package backend
 package jvm
 
-//import scala.language.unsafeNulls
-
 import dotty.tools.dotc.core.Flags.*
 import dotty.tools.dotc.core.Symbols.*
 import dotty.tools.dotc.report

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

@@ -8,7 +8,6 @@ import scala.collection.mutable
 import scala.jdk.CollectionConverters.*
 import dotty.tools.dotc.report
 
-//import scala.language.unsafeNulls
 
 /**
  * This component hosts tools and utilities used in the backend that require access to a `BTypes`

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

@@ -1,6 +1,5 @@
 package dotty.tools.backend.jvm
 
-//import scala.language.unsafeNulls
 
 import dotty.tools.dotc.CompilationUnit
 import dotty.tools.dotc.ast.Trees.{PackageDef, ValDef}
@@ -68,7 +67,7 @@ class CodeGen(val int: DottyBackendInterface, val primitives: DottyPrimitives)(
             null
 
         if sym.isClass then
-          val tastyAttrNode = if (mirrorClassNode ne null) mirrorClassNode else mainClassNode // LHOTAK
+          val tastyAttrNode = if (mirrorClassNode ne null) mirrorClassNode else mainClassNode
           genTastyAndSetAttributes(sym, tastyAttrNode)
 
         def registerGeneratedClass(classNode: ClassNode | Null, isArtifact: Boolean): Unit =

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

@@ -1,6 +1,5 @@
 package dotty.tools.backend.jvm
 
-//import scala.language.unsafeNulls
 
 import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.core.Flags.*

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

@@ -14,7 +14,6 @@ import scala.util.control.NonFatal
 import dotty.tools.dotc.core.Phases
 import dotty.tools.dotc.core.Decorators.em
 
-//import scala.language.unsafeNulls
 import scala.compiletime.uninitialized
 
 /**
@@ -189,4 +188,4 @@ final private class CompilationUnitInPostProcess(private var classes: List[Gener
   var task: Future[Unit] = uninitialized
 
   val bufferedReporting = new PostProcessorFrontendAccess.BufferingBackendReporting()
-}
+}

compiler/src/dotty/tools/dotc/classpath/ZipArchiveFileLookup.scala

@@ -3,7 +3,6 @@
  */
 package dotty.tools.dotc.classpath
 
-//import scala.language.unsafeNulls
 
 import java.io.File
 import java.net.URL

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

@@ -2,7 +2,6 @@ package dotty.tools
 package dotc
 package config
 
-//import scala.language.unsafeNulls
 
 import io.*
 

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

@@ -2,7 +2,6 @@ package dotty.tools
 package dotc
 package config
 
-import scala.language.unsafeNulls
 
 import scala.annotation.internal.sharable
 
@@ -45,7 +44,7 @@ trait PropertiesTrait {
 
   def propIsSet(name: String): Boolean                  = System.getProperty(name) != null
   def propIsSetTo(name: String, value: String): Boolean = propOrNull(name) == value
-  def propOrElse(name: String, alt: => String): String  = Option(System.getProperty(name)).getOrElse(alt)
+  def propOrElse(name: String, alt: => String | Null): String  = Option(System.getProperty(name)).getOrElse(alt)
   def propOrEmpty(name: String): String                 = propOrElse(name, "")
   def propOrNull(name: String): String                  = propOrElse(name, null)
   def propOrNone(name: String): Option[String]          = Option(propOrNull(name))

compiler/src/dotty/tools/dotc/coverage/Serializer.scala

@@ -3,7 +3,6 @@ package coverage
 
 import java.nio.file.{Path, Paths, Files}
 import java.io.Writer
-import scala.language.unsafeNulls
 import scala.collection.mutable.StringBuilder
 
 /**

compiler/src/dotty/tools/dotc/sbt/APIUtils.scala

@@ -1,7 +1,6 @@
 package dotty.tools.dotc
 package sbt
 
-//import scala.language.unsafeNulls
 
 import core.*
 import Contexts.*

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

@@ -1,7 +1,6 @@
 package dotty.tools.dotc
 package transform
 
-//import scala.language.unsafeNulls
 
 import java.io.{PrintWriter, StringWriter}
 import java.lang.reflect.{InvocationTargetException, Method => JLRMethod}

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

@@ -1,6 +1,6 @@
 package dotty.tools.dotc.util
 
-import scala.language.unsafeNulls //
+import scala.language.unsafeNulls
 
 /** A specialized implementation of GenericHashMap with standard hashCode and equals
  *  as comparison

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

@@ -1,6 +1,5 @@
 package dotty.tools.dotc.util
 
-//import scala.language.unsafeNulls
 
 import reflect.ClassTag
 import annotation.tailrec

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

@@ -2,7 +2,6 @@ package dotty.tools
 package dotc
 package util
 
-//import scala.language.unsafeNulls
 
 import core.Names.*
 

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

@@ -1,6 +1,5 @@
 package dotty.tools.dotc.util
 
-import scala.language.unsafeNulls //
 
 import collection.mutable
 

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

@@ -2,7 +2,6 @@ package dotty.tools
 package dotc
 package util
 
-//import scala.language.unsafeNulls
 
 import printing.{Showable, Printer}
 import printing.Texts.*

compiler/src/dotty/tools/io/Streamable.scala

@@ -5,7 +5,6 @@
 
 package dotty.tools.io
 
-//import scala.language.unsafeNulls
 
 import java.net.URL
 import java.io.{ BufferedInputStream, InputStream }

compiler/src/dotty/tools/runner/ScalaClassLoader.scala

@@ -1,7 +1,6 @@
 package dotty.tools
 package runner
 
-import scala.language.unsafeNulls
 
 import java.lang.ClassLoader
 import java.lang.invoke.{MethodHandles, MethodType}
@@ -64,7 +63,7 @@ object ScalaClassLoader {
   def fromURLsParallelCapable(urls: Seq[URL], parent: ClassLoader | Null = null): URLClassLoader =
     new URLClassLoader(urls.toArray, if parent == null then bootClassLoader else parent)
 
-  @sharable private val bootClassLoader: ClassLoader =
+  @sharable private val bootClassLoader: ClassLoader | Null =
     if scala.util.Properties.isJavaAtLeast("9") then
       try
         ClassLoader.getSystemClassLoader.getParent