From 83cef51e1c7f65c2a57a6117964d06eaa314500a Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 28 May 2018 14:41:45 +0200
Subject: [PATCH] Fix #4591: Unpickle type quotes with TreeReader.readTpt

---
 .../dotc/core/quoted/PickledQuotes.scala      | 27 +++++++++++--------
 .../dotc/core/tasty/DottyUnpickler.scala      |  3 +++
 .../tools/dotc/core/tasty/TreeUnpickler.scala |  7 +++++
 tests/run-with-compiler/i4591.check           |  1 +
 tests/run-with-compiler/i4591.scala           | 15 +++++++++++
 5 files changed, 42 insertions(+), 11 deletions(-)
 create mode 100644 tests/run-with-compiler/i4591.check
 create mode 100644 tests/run-with-compiler/i4591.scala

diff --git a/compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala b/compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala
index faf50b5848a6..007e47e30a5f 100644
--- a/compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala
+++ b/compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala
@@ -66,13 +66,13 @@ object PickledQuotes {
   /** Unpickle the tree contained in the TastyExpr */
   private def unpickleExpr(expr: TastyExpr[_])(implicit ctx: Context): Tree = {
     val tastyBytes = TastyString.unpickle(expr.tasty)
-    unpickle(tastyBytes, expr.args)
+    unpickle(tastyBytes, expr.args, isType = false)
   }
 
   /** Unpickle the tree contained in the TastyType */
   private def unpickleType(ttpe: TastyType[_])(implicit ctx: Context): Tree = {
     val tastyBytes = TastyString.unpickle(ttpe.tasty)
-    unpickle(tastyBytes, ttpe.args)
+    unpickle(tastyBytes, ttpe.args, isType = true)
   }
 
   // TASTY picklingtests/pos/quoteTest.scala
@@ -85,28 +85,33 @@ object PickledQuotes {
     treePkl.compactify()
     pickler.addrOfTree = treePkl.buf.addrOfTree
     pickler.addrOfSym = treePkl.addrOfSym
-    // if (tree.pos.exists)
-    //   new PositionPickler(pickler, treePkl.buf.addrOfTree).picklePositions(tree :: Nil)
 
-    // other pickle sections go here.
+    if (pickling ne noPrinter)
+      println(i"**** pickling quote of \n${tree.show}")
+
     val pickled = pickler.assembleParts()
 
-    if (pickling ne noPrinter) {
-      println(i"**** pickled quote of \n${tree.show}")
+    if (pickling ne noPrinter)
       new TastyPrinter(pickled).printContents()
-    }
 
     pickled
   }
 
   /** Unpickle TASTY bytes into it's tree */
-  private def unpickle(bytes: Array[Byte], splices: Seq[Any])(implicit ctx: Context): Tree = {
+  private def unpickle(bytes: Array[Byte], splices: Seq[Any], isType: Boolean)(implicit ctx: Context): Tree = {
     val unpickler = new TastyUnpickler(bytes, splices)
-    val tree = unpickler.unpickleExpr()
     if (pickling ne noPrinter) {
-      println(i"**** unpickled quote for \n${tree.show}")
+      println(i"**** unpickling quote from TASTY")
       new TastyPrinter(bytes).printContents()
     }
+
+    val tree =
+      if (isType) unpickler.unpickleTypeTree()
+      else unpickler.unpickleExpr()
+
+    if (pickling ne noPrinter)
+      println(i"**** unpickle quote ${tree.show}")
+
     tree
   }
 
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/DottyUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/DottyUnpickler.scala
index 5dc92ee916df..91832b997877 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/DottyUnpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/DottyUnpickler.scala
@@ -49,6 +49,9 @@ class DottyUnpickler(bytes: Array[Byte]) extends ClassfileParser.Embedded with t
   def unpickleExpr()(implicit ctx: Context): Tree =
     treeUnpickler.unpickleExpr()
 
+  def unpickleTypeTree()(implicit ctx: Context): Tree =
+    treeUnpickler.unpickleTypeTree()
+
   protected def treeSectionUnpickler(posUnpicklerOpt: Option[PositionUnpickler]): TreeSectionUnpickler = {
     new TreeSectionUnpickler(posUnpicklerOpt)
   }
diff --git a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
index 1a8fd49a5d99..5b35002530f7 100644
--- a/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
+++ b/compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala
@@ -85,6 +85,13 @@ class TreeUnpickler(reader: TastyReader,
     rdr.readTerm()
   }
 
+  def unpickleTypeTree()(implicit ctx: Context): Tree = {
+    this.roots = Set(ctx.owner)
+    val rdr = new TreeReader(reader).fork
+    ownerTree = new OwnerTree(NoAddr, 0, rdr.fork, reader.endAddr)
+    rdr.readTpt()
+  }
+
   /** The unpickled trees */
   def unpickle()(implicit ctx: Context): List[Tree] = {
     assert(roots != null, "unpickle without previous enterTopLevel")
diff --git a/tests/run-with-compiler/i4591.check b/tests/run-with-compiler/i4591.check
new file mode 100644
index 000000000000..ee1eff6a5131
--- /dev/null
+++ b/tests/run-with-compiler/i4591.check
@@ -0,0 +1 @@
+Some(9)
diff --git a/tests/run-with-compiler/i4591.scala b/tests/run-with-compiler/i4591.scala
new file mode 100644
index 000000000000..ad5119618c96
--- /dev/null
+++ b/tests/run-with-compiler/i4591.scala
@@ -0,0 +1,15 @@
+import dotty.tools.dotc.quoted.Toolbox._
+import scala.quoted._
+
+object Test {
+
+  def foo[T: Type](init: Expr[T]): Expr[Unit] = '{
+    var x = ~init
+    println(x)
+  }
+
+  def main(args: Array[String]): Unit = {
+    foo('(Option(9))).run
+  }
+
+}