From 95030c29334e57e50e8c73a91288c9b221889984 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 5 Aug 2019 23:23:01 +0200
Subject: [PATCH 1/2] Accept jars as input with -from-tasty

Recompile all classes in the given jar.
---
 compiler/src/dotty/tools/dotc/Driver.scala | 17 ++++++++++++-----
 project/scripts/cmdTests                   |  5 +++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/Driver.scala b/compiler/src/dotty/tools/dotc/Driver.scala
index b42d9984d683..4207f1ee61b5 100644
--- a/compiler/src/dotty/tools/dotc/Driver.scala
+++ b/compiler/src/dotty/tools/dotc/Driver.scala
@@ -8,6 +8,7 @@ import core.Comments.{ContextDoc, ContextDocstrings}
 import core.Contexts.{Context, ContextBase}
 import core.{MacroClassLoader, Mode, TypeError}
 import dotty.tools.dotc.ast.Positioned
+import dotty.tools.io.File
 import reporting._
 
 import scala.util.control.NonFatal
@@ -70,19 +71,25 @@ class Driver {
   protected def fromTastySetup(fileNames0: List[String], ctx0: Context): (List[String], Context) = {
     if (ctx0.settings.fromTasty.value(ctx0)) {
       // Resolve classpath and class names of tasty files
-      val (classPaths, classNames) = fileNames0.map { name =>
+      val (classPaths, classNames) = fileNames0.flatMap { name =>
         val path = Paths.get(name)
-        if (!name.endsWith(".tasty")) ("", name)
+        if (name.endsWith(".jar")) {
+          new dotty.tools.io.Jar(File(name)).iterator.collect {
+            case e if e.getName.endsWith(".tasty") =>
+              (name, e.getName.stripSuffix(".tasty").replace("/", "."))
+          }.toList
+        }
+        else if (!name.endsWith(".tasty")) ("", name) :: Nil
         else if (Files.exists(path)) {
           TastyFileUtil.getClassName(path) match {
-            case Some(res) => res
+            case Some(res) => res:: Nil
             case _ =>
               ctx0.error(s"Could not load classname from $name.")
-              ("", name)
+              ("", name) :: Nil
           }
         } else {
           ctx0.error(s"File $name does not exist.")
-          ("", name)
+          ("", name):: Nil
         }
       }.unzip
       val ctx1 = ctx0.fresh
diff --git a/project/scripts/cmdTests b/project/scripts/cmdTests
index 93384739a345..79aa4a14ceeb 100755
--- a/project/scripts/cmdTests
+++ b/project/scripts/cmdTests
@@ -13,6 +13,11 @@ clear_out "$OUT"
 "$SBT" ";dotc $SOURCE -d $OUT ;dotc -from-tasty -classpath $OUT -d $OUT1 $MAIN ;dotr -classpath $OUT1 $MAIN" > "$tmp"
 grep -qe "$EXPECTED_OUTPUT" "$tmp"
 
+echo "testing sbt dotc -from-tasty from a jar and dotr -classpath"
+clear_out "$OUT"
+"$SBT" ";dotc -d $OUT/out.jar $SOURCE ;dotc -from-tasty -d $OUT1 $OUT/out.jar ;dotr -classpath $OUT1 $MAIN" > "$tmp"
+grep -qe "$EXPECTED_OUTPUT" "$tmp"
+
 # check that `sbt dotc -decompile` runs
 echo "testing sbt dotc -decompile"
 "$SBT" ";dotc -decompile -color:never -classpath $OUT $MAIN" > "$tmp"

From f6288a55e2864ee9fdc41f02052762aac9046396 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Tue, 6 Aug 2019 19:20:59 +0200
Subject: [PATCH 2/2] Code format cleanup

---
 compiler/src/dotty/tools/dotc/Driver.scala | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/compiler/src/dotty/tools/dotc/Driver.scala b/compiler/src/dotty/tools/dotc/Driver.scala
index 4207f1ee61b5..f3ab08a7c0cc 100644
--- a/compiler/src/dotty/tools/dotc/Driver.scala
+++ b/compiler/src/dotty/tools/dotc/Driver.scala
@@ -79,7 +79,8 @@ class Driver {
               (name, e.getName.stripSuffix(".tasty").replace("/", "."))
           }.toList
         }
-        else if (!name.endsWith(".tasty")) ("", name) :: Nil
+        else if (!name.endsWith(".tasty"))
+          ("", name) :: Nil
         else if (Files.exists(path)) {
           TastyFileUtil.getClassName(path) match {
             case Some(res) => res:: Nil
@@ -89,7 +90,7 @@ class Driver {
           }
         } else {
           ctx0.error(s"File $name does not exist.")
-          ("", name):: Nil
+          ("", name) :: Nil
         }
       }.unzip
       val ctx1 = ctx0.fresh