Merge pull request #4081 from dotty-staging/fix-#4044

Fix #4044: Change quote pickled representation

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -1133,19 +1133,14 @@ class TreeUnpickler(reader: TastyReader,
       val idx = readNat()
       val args = until(end)(readTerm())
       val splice = splices(idx)
-
+      val reifiedArgs = args.map(arg => if (arg.isTerm) new TreeExpr(arg) else new TreeType(arg))
       if (isType) {
-        val quotedType =
-          if (args.isEmpty) splice.asInstanceOf[quoted.Type[_]]
-          else splice.asInstanceOf[Seq[Any] => quoted.Type[_]](args.map(tree => new TreeType(tree)))
+        val quotedType = splice.asInstanceOf[Seq[Any] => quoted.Type[_]](reifiedArgs)
         PickledQuotes.quotedTypeToTree(quotedType)
       } else {
-        val quotedExpr =
-          if (args.isEmpty) splice.asInstanceOf[quoted.Expr[_]]
-          else splice.asInstanceOf[Seq[Any] => quoted.Expr[_]](args.map(tree => new TreeExpr(tree)))
+        val quotedExpr = splice.asInstanceOf[Seq[Any] => quoted.Expr[_]](reifiedArgs)
         PickledQuotes.quotedExprToTree(quotedExpr)
       }
-
     }
 
 // ------ Setting positions ------------------------------------------------

compiler/src/dotty/tools/dotc/transform/ReifyQuotes.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+class Test {
+
+  val a = '(1)
+  '{
+    a // error
+    ~a
+    '(~a) // error
+    '( '(~a) ) // error
+  }
+
+}

tests/neg/i4044a.scala

@@ -0,0 +1,18 @@
+import scala.quoted._
+
+class Test {
+
+  '{
+
+    val b = '(3)
+
+    '{
+      b // error
+      ~(b)
+      ~('(b)) // error
+      '( '(~b) ) // error
+    }
+
+  }
+
+}

tests/neg/i4044b.scala

@@ -0,0 +1 @@
+3

tests/run-with-compiler/i4044a.check

@@ -0,0 +1,17 @@
+import scala.quoted._
+import dotty.tools.dotc.quoted.Toolbox._
+
+class Foo {
+  def foo: Unit = {
+    val e: Expr[Int] = '(3)
+    val q = '{ ~( '{ ~e } ) }
+    println(q.show)
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val f = new Foo
+    f.foo
+  }
+}

tests/run-with-compiler/i4044a.scala

@@ -0,0 +1,5 @@
+{
+  var x: Int = 4
+  x = 3
+  x
+}

tests/run-with-compiler/i4044b.check

@@ -0,0 +1,27 @@
+import scala.quoted._
+import dotty.tools.dotc.quoted.Toolbox._
+
+sealed abstract class VarRef[T] {
+  def update(expr: Expr[T]): Expr[Unit]
+  def expr: Expr[T]
+}
+
+object VarRef {
+  def apply[T: Type, U](init: Expr[T])(body: VarRef[T] => Expr[U]): Expr[U] = '{
+    var x = ~init
+    ~body(
+      new VarRef {
+        def update(e: Expr[T]): Expr[Unit] = '{ x = ~e }
+        def expr: Expr[T] = '(x)
+      }
+    )
+  }
+
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val q = VarRef(4)(varRef => '{ ~varRef.update(3); ~varRef.expr })
+    println(q.show)
+  }
+}

tests/run-with-compiler/i4044b.scala

@@ -0,0 +1 @@
+5

tests/run-with-compiler/i4044c.check

@@ -0,0 +1,16 @@
+import scala.quoted._
+import dotty.tools.dotc.quoted.Toolbox._
+
+class Foo {
+  def foo: Unit = {
+    val q = '{ ~( '{ ~( '{ 5 } ) } ) }
+    println(q.show)
+  }
+}
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val f = new Foo
+    f.foo
+  }
+}