Test stdlib from TASTy directly from Jar

Passing the class names will no be supported in the future.

Author: nicolasstucki

compiler/src/dotty/tools/dotc/Driver.scala

@@ -86,6 +86,7 @@ class Driver {
   protected def fromTastySetup(fileNames0: List[String], ctx0: Context): (List[String], Context) =
     given Context = ctx0
     if (ctx0.settings.fromTasty.value) {
+      val fromTastyBlacklist = ctx0.settings.YfromTastyBlacklist.value.toSet
       // Resolve classpath and class names of tasty files
       val (classPaths, classNames) = fileNames0.flatMap { name =>
         val path = Paths.get(name)
@@ -96,7 +97,7 @@ class Driver {
           Nil
         else if name.endsWith(".jar") then
           new dotty.tools.io.Jar(File(name)).toList.collect {
-            case e if e.getName.endsWith(".tasty") =>
+            case e if e.getName.endsWith(".tasty") && !fromTastyBlacklist(e.getName) =>
               (name, e.getName.stripSuffix(".tasty").replace("/", "."))
           }
         else

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

@@ -45,7 +45,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val language: Setting[List[String]] = MultiStringSetting("-language", "feature", "Enable one or more language features.") withAbbreviation "--language"
   val rewrite: Setting[Option[Rewrites]] = OptionSetting[Rewrites]("-rewrite", "When used in conjunction with a `...-migration` source version, rewrites sources to migrate to new version.") withAbbreviation "--rewrite"
   val silentWarnings: Setting[Boolean] = BooleanSetting("-nowarn", "Silence all warnings.") withAbbreviation "--no-warnings"
-  val fromTasty: Setting[Boolean] = BooleanSetting("-from-tasty", "Compile classes from tasty in classpath. The arguments are used as class names.") withAbbreviation "--from-tasty"
+  val fromTasty: Setting[Boolean] = BooleanSetting("-from-tasty", "Compile classes from tasty files. The arguments are .tasty or .jar files.") withAbbreviation "--from-tasty"
 
   val newSyntax: Setting[Boolean] = BooleanSetting("-new-syntax", "Require `then` and `do` in control expressions.")
   val oldSyntax: Setting[Boolean] = BooleanSetting("-old-syntax", "Require `(...)` around conditions.")
@@ -158,6 +158,7 @@ class ScalaSettings extends Settings.SettingGroup {
   val YretainTrees: Setting[Boolean] = BooleanSetting("-Yretain-trees", "Retain trees for top-level classes, accessible from ClassSymbol#tree")
   val Ysemanticdb: Setting[Boolean] = BooleanSetting("-Ysemanticdb", "Store information in SemanticDB.")
   val YshowTreeIds: Setting[Boolean] = BooleanSetting("-Yshow-tree-ids", "Uniquely tag all tree nodes in debugging output.")
+  val YfromTastyBlacklist: Setting[List[String]] = MultiStringSetting("-Yfrom-tasty-blacklist", "file", "List of `tasty` files in jar files that will not be loaded when using -from-tasty")
 
   val YprofileEnabled: Setting[Boolean] = BooleanSetting("-Yprofile-enabled", "Enable profiling.")
   val YprofileDestination: Setting[String] = StringSetting("-Yprofile-destination", "file", "Where to send profiling output - specify a file, default is to the console.", "")

stdlib-bootstrapped-tasty-tests/test/BootstrappedStdLibTASYyTest.scala

@@ -10,6 +10,7 @@ import dotty.tools.dotc.util.ClasspathFromClassloader
 import scala.quoted._
 
 import java.io.File.pathSeparator
+import java.io.File.separator
 
 class BootstrappedStdLibTASYyTest:
 
@@ -23,13 +24,6 @@ class BootstrappedStdLibTASYyTest:
   @Test def testFromTasty: Unit =
     compileFromTasty(loadBlacklisted.union(compileBlacklisted))
 
-  @Ignore
-  @Test def testWhiteListFromTasty: Unit =
-    val whitelist = Set(
-      "scala.collection.mutable.StringBuilder"
-    )
-    compileFromTasty(x => !whitelist(x))
-
   @Test def blacklistNoDuplicates =
     def testDup(name: String, list: List[String], set: Set[String]) =
       assert(list.size == set.size,
@@ -111,15 +105,17 @@ object BootstrappedStdLibTASYyTest:
     val hasErrors = inspector.inspectTastyFilesInJar(scalaLibJarPath)
     assert(!hasErrors, "Errors reported while loading from TASTy")
 
-  def compileFromTasty(blacklisted: String => Boolean): Unit = {
+  def compileFromTasty(blacklisted: Iterable[String]): Unit = {
     val driver = new dotty.tools.dotc.Driver
-    val currentClasspath = ClasspathFromClassloader(getClass.getClassLoader)
-    val classNames = scalaLibJarTastyClassNames.filterNot(blacklisted)
+    val yFromTastyBlacklist =
+      blacklisted.map(x => x.replace(".", separator) + ".tasty").mkString("-Yfrom-tasty-blacklist:", ",", "")
     val args = Array(
-      "-classpath", s"$scalaLibJarPath$pathSeparator$currentClasspath",
+      "-classpath", ClasspathFromClassloader(getClass.getClassLoader),
       "-from-tasty",
-      "-nowarn"
-    ) ++ classNames
+      "-nowarn",
+      yFromTastyBlacklist,
+      scalaLibJarPath,
+    )
     val reporter = driver.process(args)
     assert(reporter.errorCount == 0, "Errors while re-compiling")
   }