WIP Package stdlib compiled with Scala 2 + TASTy

Author: nicolasstucki

project/Build.scala

@@ -939,6 +939,46 @@ object Build {
       },
       mimaCheckDirection := "both",
       mimaBinaryIssueFilters ++= MiMaFilters.LibraryBootstrappedForward,
+      libraryDependencies += // For jar packaging
+        ("org.scala-lang" % "scala-library" % stdlibVersion(Bootstrapped)),
+      exportJars := true,
+      Compile / packageBin / artifactName := { (sv: ScalaVersion, module: ModuleID, artifact: Artifact) =>
+        artifact.name + "-" + stdlibVersion(Bootstrapped) + "-" + module.revision + "." + artifact.extension
+      },
+      Compile / packageBin / mappings := {
+        val s = streams.value
+        val report = updateClassifiers.value
+        val scalaLibraryJar =
+          // FIXME
+          report.select(
+              configuration = configurationFilter("sourcedeps"),
+              module = (_: ModuleID).name == "scala-library",
+              artifact = artifactFilter(`type` = "src")).headOption.getOrElse {
+            sys.error(s"Could not fetch scala-library sources")
+          }.getParentFile / "scala-library-2.13.10.jar"
+        val cacheDir = s.cacheDirectory
+        val trgDir = (Compile / sourceManaged).value / "scala-library-bin"
+        FileFunction.cached(cacheDir / "fetchScalaLibraryBin",
+            FilesInfo.lastModified, FilesInfo.exists) { dependencies =>
+          s.log.info(s"Unpacking scala-library classfiles to $trgDir...")
+          if (trgDir.exists)
+            IO.delete(trgDir)
+          IO.createDirectory(trgDir)
+          IO.unzip(scalaLibraryJar, trgDir)
+
+          (trgDir ** "*.class").get.toSet
+        } (Set(scalaLibraryJar)).toSeq
+        val allScalaLibraryJarFiles =
+          trgDir.allPaths.get().filterNot(_.getName.endsWith(".MF")) // TODO use parts of the old manifest?
+        val allScalaLibraryJarMappings: Seq[(java.io.File, String)] =
+          allScalaLibraryJarFiles.zip(allScalaLibraryJarFiles.map(_.relativeTo(trgDir).get.getPath))
+
+        val tastyFileMappings: Seq[(java.io.File, String)] =
+          (Compile / packageBin / mappings).value.filter(_._1.getName.endsWith(".tasty"))
+
+        allScalaLibraryJarMappings ++ tastyFileMappings
+      }
+
     )
 
   /** Scala library compiled by dotty using the latest published sources of the library