From df0d9eadf789b1315a1c73522c5642127cdbdeff Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Thu, 17 Nov 2022 15:51:15 +0100
Subject: [PATCH 1/2] Disallow local term references in staged types

Fixes #16355
Fixes #15917
---
 .../dotc/transform/PCPCheckAndHeal.scala      |  8 +++--
 tests/neg-macros/i15917.scala                 |  6 ++++
 tests/neg-macros/i16355a.scala                | 35 +++++++++++++++++++
 tests/neg-macros/i16355b.scala                |  4 +++
 4 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 tests/neg-macros/i15917.scala
 create mode 100644 tests/neg-macros/i16355a.scala
 create mode 100644 tests/neg-macros/i16355b.scala

diff --git a/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala b/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
index 1d0ed035df09..4669dc86982d 100644
--- a/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
@@ -176,8 +176,10 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
   /** If the type refers to a locally defined symbol (either directly, or in a pickled type),
    *  check that its staging level matches the current level.
    *  - Static types and term are allowed at any level.
-   *  - If a type reference is used a higher level, then it is inconsistent. Will attempt to heal before failing.
-   *  - If a term reference is used a different level, then it is inconsistent.
+   *  - If a type reference is used a higher level, then it is inconsistent.
+   *    Will attempt to heal before failing.
+   *  - If a term reference is used a higher level, then it is inconsistent.
+   *    It can not be healed because the term will not exists in the any future stage.
    *
    *  If `T` is a reference to a type at the wrong level, try to heal it by replacing it with
    *  a type tag of type `quoted.Type[T]`.
@@ -206,6 +208,8 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
               tryHeal(prefix.symbol, tp, pos)
             case _ =>
               mapOver(tp)
+        case tp @ TermRef(NoPrefix, _) if !tp.symbol.isStatic && level > levelOf(tp.symbol) =>
+          levelError(tp.symbol, tp, pos)
         case tp: ThisType if level != -1 && level != levelOf(tp.cls) =>
           levelError(tp.cls, tp, pos)
         case tp: AnnotatedType =>
diff --git a/tests/neg-macros/i15917.scala b/tests/neg-macros/i15917.scala
new file mode 100644
index 000000000000..3eecc38b21f9
--- /dev/null
+++ b/tests/neg-macros/i15917.scala
@@ -0,0 +1,6 @@
+import scala.quoted.*
+
+def m(using Quotes): Expr[Option[_]] =
+  val s = 3
+  type st = s.type
+  '{ Some(${ Expr(s) }: st) } // error
diff --git a/tests/neg-macros/i16355a.scala b/tests/neg-macros/i16355a.scala
new file mode 100644
index 000000000000..8870b7777263
--- /dev/null
+++ b/tests/neg-macros/i16355a.scala
@@ -0,0 +1,35 @@
+//> using scala "3.2.1"
+import scala.quoted.Expr
+import scala.quoted.Type
+import scala.quoted.quotes
+import scala.quoted.Quotes
+
+object macros {
+
+  inline transparent def mkNames[A]: List[Any] = ${ mkNamesImpl[A] }
+
+  def mkNamesImpl[A: Type](using Quotes): Expr[List[Any]] = {
+    import quotes.reflect._
+
+    val fieldNames = TypeRepr.of[A].typeSymbol.declaredFields.map(_.name)
+
+    val types = fieldNames
+      .map { f =>
+        val t1 = ConstantType(StringConstant(f))
+        t1.asType match {
+          case '[t1Type] => TypeRepr.of[(t1Type, "aa")]
+        }
+      }
+      .reduceLeft[TypeRepr](OrType(_, _))
+
+    types.asType match {
+      case '[ttt] =>
+        Expr.ofList[ttt](
+          fieldNames.map { v =>
+            Expr[(v.type, "aa")](v -> "aa").asExprOf[ttt] // error
+          }
+        )
+    }
+  }
+
+}
diff --git a/tests/neg-macros/i16355b.scala b/tests/neg-macros/i16355b.scala
new file mode 100644
index 000000000000..763810979ddf
--- /dev/null
+++ b/tests/neg-macros/i16355b.scala
@@ -0,0 +1,4 @@
+import scala.quoted._
+def test(v: String)(using Quotes): Any =
+  Type.of : Type[v.type] // error
+  Type.of[v.type] // error

From 4e4bf207fd521f16d743d4bbe64d11f7cf076c9e Mon Sep 17 00:00:00 2001
From: Nicolas Stucki <nicolas.stucki@gmail.com>
Date: Mon, 23 Jan 2023 17:18:16 +0100
Subject: [PATCH 2/2] Update
 compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala

Co-authored-by: Guillaume Martres <smarter@ubuntu.com>
---
 compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala b/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
index 4669dc86982d..e2e494a95074 100644
--- a/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
+++ b/compiler/src/dotty/tools/dotc/transform/PCPCheckAndHeal.scala
@@ -179,7 +179,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
    *  - If a type reference is used a higher level, then it is inconsistent.
    *    Will attempt to heal before failing.
    *  - If a term reference is used a higher level, then it is inconsistent.
-   *    It can not be healed because the term will not exists in the any future stage.
+   *    It cannot be healed because the term will not exist in any future stage.
    *
    *  If `T` is a reference to a type at the wrong level, try to heal it by replacing it with
    *  a type tag of type `quoted.Type[T]`.