Add AbstractFile.resolveSibling

Author: nicolasstucki

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

@@ -36,11 +36,8 @@ object FileUtils {
     /** Returns the tasty file associated with this class file */
     def classToTasty: Option[AbstractFile] =
       assert(file.isClass, s"non-class: $file")
-      val parent = file match  // TODO: simplify when #3552 is fixed
-        case file: io.ZipArchive#Entry => file.parent
-        case _ => file.container
       val tastyName = classNameToTasty(file.name)
-      Option(parent.lookupName(tastyName, directory = false))
+      Option(file.resolveSibling(tastyName))
   }
 
   extension (file: JFile) {

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

@@ -145,10 +145,7 @@ class ExtractDependencies extends Phase {
         // Dependency is external -- source is undefined
         processExternalDependency(depFile, dep.to.binaryClassName)
       } else if (depFile.extension == "tasty") {
-        val parent = depFile match  // TODO: simplify when #3552 is fixed
-          case depFile: io.ZipArchive#Entry => depFile.parent
-          case _ => depFile.container
-        val depClassFile = parent.lookupName(dep.to.binaryClassName + ".class", directory = false)
+        val depClassFile = depFile.resolveSibling(dep.to.binaryClassName + ".class")
         if depClassFile != null then
           processExternalDependency(depClassFile, dep.to.binaryClassName)
       } else if (allowLocal || depFile.file != sourceFile) {

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

@@ -250,6 +250,12 @@ abstract class AbstractFile extends Iterable[AbstractFile] {
     file
   }
 
+  /** Returns the sibling abstract file in the parent of this abstract file or directory.
+   *  If there is no such file, returns `null`.
+   */
+  def resolveSibling(name: String): AbstractFile =
+    container.lookupName(name, directory = false)
+
   private def fileOrSubdirectoryNamed(name: String, isDir: Boolean): AbstractFile =
     lookupName(name, isDir) match {
       case null =>

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

@@ -72,6 +72,8 @@ abstract class ZipArchive(override val jpath: JPath, release: Option[String]) ex
     // have to keep this name for compat with sbt's compiler-interface
     def getArchive: ZipFile = null
     override def underlyingSource: Option[ZipArchive] = Some(self)
+    override def resolveSibling(name: String): AbstractFile =
+      parent.lookupName(name, directory = false)
     override def toString: String = self.path + "(" + path + ")"
   }