Restrict access to the classloader to Context only.

Author: sjrd

build.sbt

@@ -127,6 +127,7 @@ lazy val tastyQuery =
         import com.typesafe.tools.mima.core.*
         Seq(
           // private[tastyquery], not an issue
+          ProblemFilters.exclude[DirectMissingMethodProblem]("tastyquery.Contexts#Context.classloader"),
           ProblemFilters.exclude[MissingClassProblem]("tastyquery.Utils"),
           ProblemFilters.exclude[MissingClassProblem]("tastyquery.Utils$"),
           // private, not an issue

tasty-query/shared/src/main/scala/tastyquery/Contexts.scala

@@ -58,15 +58,19 @@ object Contexts {
     * The same instance of [[Classpaths.Classpath]] can be reused to create
     * several [[Context]]s, if necessary.
     */
-  final class Context private[Contexts] (private[tastyquery] val classloader: Loader) {
+  final class Context private[Contexts] (classloader: Loader) {
     private given Context = this
 
     private val sourceFiles = mutable.HashMap.empty[String, SourceFile]
 
     private val (RootPackage @ _, EmptyPackage @ _) = PackageSymbol.createRoots()
 
+    private[tastyquery] def hasGenericTuples: Boolean = classloader.hasGenericTuples
+
     val defn: Definitions = Definitions(this: @unchecked, RootPackage, EmptyPackage)
 
+    private[tastyquery] def internalClasspathForTestsOnly: Classpath = classloader.classpath
+
     private[tastyquery] def getSourceFile(path: String): SourceFile =
       sourceFiles.getOrElseUpdate(path, new SourceFile(path))
 

tasty-query/shared/src/main/scala/tastyquery/Definitions.scala

@@ -517,7 +517,7 @@ final class Definitions private[tastyquery] (
     end functionClassOf
   end PolyFunctionType
 
-  lazy val hasGenericTuples = withRestrictedContext(ctx.classloader.hasGenericTuples)
+  lazy val hasGenericTuples = withRestrictedContext(ctx.hasGenericTuples)
 
   lazy val uninitializedMethod: Option[TermSymbol] =
     withRestrictedContext {

tasty-query/shared/src/main/scala/tastyquery/reader/ReaderContext.scala

@@ -69,7 +69,7 @@ private[reader] final class ReaderContext(underlying: Context):
   def getSourceFile(path: String): SourceFile =
     underlying.getSourceFile(path)
 
-  def hasGenericTuples: Boolean = underlying.classloader.hasGenericTuples
+  def hasGenericTuples: Boolean = underlying.hasGenericTuples
 
   def createObjectMagicMethods(cls: ClassSymbol): Unit =
     underlying.defn.createObjectMagicMethods(cls)

tasty-query/shared/src/test/scala/tastyquery/ClasspathEntrySuite.scala

@@ -9,7 +9,7 @@ import tastyquery.testutil.TestPlatform
 class ClasspathEntrySuite extends UnrestrictedUnpicklingSuite:
 
   def scala3ClasspathEntry(using Context): ClasspathEntry =
-    ctx.classloader.classpath(TestPlatform.scala3ClasspathIndex)
+    ctx.internalClasspathForTestsOnly(TestPlatform.scala3ClasspathIndex)
 
   def lookupSyms(entry: ClasspathEntry)(using Context): IArray[Symbol] =
     IArray.from(ctx.findSymbolsByClasspathEntry(entry))