Fix #7048: Heal phase inconsistent path dependent types

Author: nicolasstucki

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

@@ -117,7 +117,8 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
           // Replace it with a properly encoded type splice. This is the normal for expected for type splices.
           tp.prefix.select(tpnme.splice)
         case tp: NamedType =>
-          checkSymLevel(tp.symbol, tp, pos) match {
+          if (tp.prefix.isInstanceOf[TermRef] && tp.prefix.isStable) tp
+          else checkSymLevel(tp.symbol, tp, pos) match {
             case Some(tpRef) => tpRef.tpe
             case _ =>
               if (tp.symbol.is(Param)) tp

tests/neg/i5954b.scala

@@ -0,0 +1,11 @@
+abstract class MatcherFactory1[A] {
+  class AndNotWord
+}
+
+object MatcherFactory1 {
+  import scala.quoted._
+
+  def impl[T](self: Expr[MatcherFactory1[T]#AndNotWord]) given QuoteContext =
+    '{ val a: Any = $self } // error: access to type T from wrong staging level
+
+}

tests/neg/i5954c.scala

@@ -0,0 +1,11 @@
+abstract class MatcherFactory1 {
+  class AndNotWord[A]
+}
+
+object MatcherFactory1 {
+  import scala.quoted._
+
+  def impl[T](self: Expr[MatcherFactory1#AndNotWord[T]]) given QuoteContext =
+    '{ val a: Any = $self } // error: access to type T from wrong staging level
+
+}

tests/neg/i7048.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+trait IsExpr {
+  type Underlying
+}
+
+def foo: IsExpr = ???
+
+def g(e: IsExpr) given (tu: Type[e.Underlying]): Unit = ???
+
+def mcrImpl: Unit = {
+  g(foo) // error
+}

tests/neg/i7048b.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+trait IsExpr {
+  type Underlying
+}
+
+def foo: IsExpr = ???
+
+def g(e: IsExpr) given (tu: Type[e.Underlying]): Unit = ???
+
+def mcrImpl: Unit = {
+  g(foo) given '[foo.Underlying] // error: => IsExpr(foo) is not stable
+}

tests/pos/i5954b.scala

@@ -0,0 +1,15 @@
+abstract class MatcherFactory1 {
+  class AndNotWord[A]
+}
+
+object MatcherFactory1 {
+  import scala.quoted._
+
+  def impl(self: Expr[MatcherFactory1#AndNotWord[Int]]) given QuoteContext =
+    '{ val a: Any = $self }
+
+
+  def impl[T: Type](self: Expr[MatcherFactory1#AndNotWord[T]]) given QuoteContext =
+    '{ val a: Any = $self }
+
+}

tests/pos/i5954c.scala

@@ -0,0 +1,15 @@
+abstract class MatcherFactory1[A] {
+  class AndNotWord
+}
+
+object MatcherFactory1 {
+  import scala.quoted._
+
+  def impl(self: Expr[MatcherFactory1[Int]#AndNotWord]) given QuoteContext =
+    '{ val a: Any = $self }
+
+
+  def impl[T: Type](self: Expr[MatcherFactory1[T]#AndNotWord]) given QuoteContext =
+    '{ val a: Any = $self }
+
+}

tests/pos/i5954d.scala

@@ -0,0 +1,15 @@
+abstract class MatcherFactory1 {
+  type AndNotWord
+}
+
+object MatcherFactory1 {
+  import scala.quoted._
+
+  def impl(self: Expr[MatcherFactory1#AndNotWord]) given QuoteContext =
+    '{ val a: Any = $self }
+
+
+  def impl2[T: Type](a: MatcherFactory1)(self: Expr[T])(implicit ev: T =:= a.AndNotWord, qctx: QuoteContext) =
+    '{ val a: Any = $self }
+
+}

tests/pos/i7048.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+trait IsExpr[T] {
+  type Underlying
+  def expr: Expr[Underlying]
+}
+
+def f(x: Any): String = x.toString
+
+def g[T] given (e: IsExpr[T], tu: Type[e.Underlying]): given QuoteContext => Expr[String] = {
+  val underlying: Expr[e.Underlying] = e.expr
+  '{f($underlying)}
+}

tests/pos/i7048b.scala

@@ -0,0 +1,12 @@
+import scala.quoted._
+
+trait IsExpr {
+  type Underlying
+}
+
+val foo: IsExpr = ???
+
+def g() given QuoteContext: Unit = {
+  val a = '[foo.Underlying]
+  ()
+}

tests/pos/i7048c.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+trait IsExpr {
+  type Underlying
+}
+
+val foo: IsExpr = ???
+
+def g(e: IsExpr) given (tu: Type[e.Underlying]): Unit = ???
+
+def mcrImpl given QuoteContext: Unit = {
+  g(foo)
+}

tests/pos/i7048d.scala

@@ -0,0 +1,13 @@
+import scala.quoted._
+
+trait IsExpr {
+  class Underlying
+}
+
+val foo: IsExpr = ???
+
+def g(e: IsExpr) given (tu: Type[e.Underlying]): Unit = ???
+
+def mcrImpl given QuoteContext: Unit = {
+  g(foo)
+}