From 3ecfc57960364d121156f46e3649f0c1bc9f33d8 Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 4 Jan 2021 13:43:58 +0100
Subject: [PATCH] Fix #10355: Run PostTyper before Staging

PostTyper marks compilation units with `needsStaging` to enable this phase.
---
 compiler/src/dotty/tools/dotc/transform/Staging.scala | 2 ++
 compiler/src/dotty/tools/repl/ReplCompiler.scala      | 2 +-
 compiler/test-resources/repl/i10355                   | 5 +++++
 3 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 compiler/test-resources/repl/i10355

diff --git a/compiler/src/dotty/tools/dotc/transform/Staging.scala b/compiler/src/dotty/tools/dotc/transform/Staging.scala
index aa895fd01021..20183f71fc38 100644
--- a/compiler/src/dotty/tools/dotc/transform/Staging.scala
+++ b/compiler/src/dotty/tools/dotc/transform/Staging.scala
@@ -35,6 +35,8 @@ class Staging extends MacroTransform {
 
   override def phaseName: String = Staging.name
 
+  override def runsAfter: Set[String] = Set(PostTyper.name)
+
   override def allowsImplicitSearch: Boolean = true
 
   override def checkPostCondition(tree: Tree)(using Context): Unit =
diff --git a/compiler/src/dotty/tools/repl/ReplCompiler.scala b/compiler/src/dotty/tools/repl/ReplCompiler.scala
index dc5e9b87b715..3580336830be 100644
--- a/compiler/src/dotty/tools/repl/ReplCompiler.scala
+++ b/compiler/src/dotty/tools/repl/ReplCompiler.scala
@@ -34,8 +34,8 @@ class ReplCompiler extends Compiler {
   override protected def frontendPhases: List[List[Phase]] = List(
     List(new REPLFrontEnd),
     List(new CollectTopLevelImports),
+    List(new PostTyper),
     List(new Staging),
-    List(new PostTyper)
   )
 
   def newRun(initCtx: Context, state: State): Run = new Run(this, initCtx) {
diff --git a/compiler/test-resources/repl/i10355 b/compiler/test-resources/repl/i10355
new file mode 100644
index 000000000000..bfe3af835c87
--- /dev/null
+++ b/compiler/test-resources/repl/i10355
@@ -0,0 +1,5 @@
+scala> import scala.quoted._
+scala> def foo(expr: Expr[Any])(using Quotes) = expr match { case '{ $x: t } => '{ $x: Any } }
+def foo(expr: quoted.Expr[Any])(using x$2: quoted.Quotes): quoted.Expr[Any]
+scala> def bar(expr: Expr[Any])(using Quotes) = expr match { case '{ $x: t } => '{ val a: t = ??? ; ???} }
+def bar(expr: quoted.Expr[Any])(using x$2: quoted.Quotes): quoted.Expr[Nothing]