Use canonical underlying type reference

Author: nicolasstucki

compiler/src/dotty/tools/dotc/typer/QuotesAndSplices.scala

@@ -180,8 +180,9 @@ trait QuotesAndSplices {
     else
       val tree1 = typedSelect(untpd.Select(tree.expr, tpnme.Underlying), pt)(using spliceContext).withSpan(tree.span)
       val msg = em"Consider using canonical type reference ${tree1.tpe} instead"
-      if sourceVersion.isAtLeast(`3.1-migration`) then report.error(msg, tree.srcPos)
-      else report.warning(msg, tree.srcPos)
+      // if sourceVersion.isAtLeast(`3.1-migration`) then
+      report.error(msg, tree.srcPos)
+      // else report.warning(msg, tree.srcPos)
       tree1
   }
 

tests/neg-macros/i4774b.scala

@@ -3,8 +3,8 @@ import scala.quoted._
 
 object Test {
   def loop[T](x: Expr[T])(implicit t: Type[T], qctx: QuoteContext): Expr[T] = '{
-    val y: $t = $x;
-    ${loop[$t]( // error
+    val y: t.Underlying = $x;
+    ${loop[t.Underlying]( // error
       'y
     )}
   }

tests/neg-macros/i6997.scala

@@ -2,7 +2,7 @@
 import scala.quoted._
 class Foo {
   def mcrImpl(body: Expr[Any])(using t: Type[_ <: Any])(using ctx: QuoteContext): Expr[Any] = '{
-    val tmp = ???.asInstanceOf[$t] // error // error
+    val tmp = ???.asInstanceOf[t.Underlying] // error // error
     tmp
   }
 }

tests/neg-macros/i7048e.scala

@@ -16,18 +16,18 @@ abstract class Test {
       import t.given
       println(summon[Type[t.T]].show)
       // val r = '{Option.empty[t.T]} // access to value t from wrong staging level
-      val r2 = '{Option.empty[${t.T}]} // works
+      val r2 = '{Option.empty[t.T.Underlying]} // works
     }
 
     {
-      val r1 = '{Option.empty[${T}]} // works
-      val r2 = '{Option.empty[List[${T}]]} // works
-      val r3 = '{summon[Type[${T}]]} // error: is not stable
-      val r4 = '{summon[${T} <:< Any]} // error: is not stable
+      val r1 = '{Option.empty[T.Underlying]} // works
+      val r2 = '{Option.empty[List[T.Underlying]]} // works
+      val r3 = '{summon[Type[T.Underlying]]} // error: is not stable
+      val r4 = '{summon[T.Underlying <:< Any]} // error: is not stable
     }
 
     {
-      val s = '{Option.empty[${T}]} // works
+      val s = '{Option.empty[T.Underlying]} // works
       val r = '{identity($s)} // works
       val r2 = '{identity(${s: Expr[Option[T]]})} // error // error : is not stable
     }

tests/pos-macros/i4023c/Macro_1.scala

@@ -1,5 +1,5 @@
 import scala.quoted._
 object Macro {
   inline def ff[T](x: T): T = ${ impl('x)('[T], summon[QuoteContext]) }
-  def impl[T](x: Expr[T])(implicit t: Type[T], qctx: QuoteContext): Expr[T] = '{ $x: $t }
+  def impl[T](x: Expr[T])(implicit t: Type[T], qctx: QuoteContext): Expr[T] = '{ $x: T }
 }

tests/pos-macros/i4774a.scala

@@ -3,7 +3,7 @@ import scala.quoted._
 
 object Test {
   def loop[T](x: Expr[T])(implicit t: Type[T], qctx: QuoteContext): Expr[T] = '{
-    val y: $t = $x
+    val y: T = $x
     ${loop('y)}
   }
 }

tests/pos-macros/i6210/Macros_1.scala

@@ -7,8 +7,8 @@ object Macro {
   def impl[A : Type, B : Type](using QuoteContext): Expr[Any] = {
     val t = '[Map[A, B]]
     '{
-      new Object().asInstanceOf[$t]
-      ???.asInstanceOf[$t]
+      new Object().asInstanceOf[t.Underlying]
+      ???.asInstanceOf[t.Underlying]
     }
   }
 }

tests/pos-macros/i7048e.scala

@@ -16,18 +16,18 @@ abstract class Test {
       import t.given
       println(summon[Type[t.T]].show)
       // val r = '{Option.empty[t.T]} // access to value t from wrong staging level
-      val r2 = '{Option.empty[${t.T}]}
+      val r2 = '{Option.empty[t.T.Underlying]}
     }
 
     {
-      val r1 = '{Option.empty[${T}]} // works
-      val r2 = '{Option.empty[List[${T}]]} // works
-      // val r3 = '{summon[Type[${T}]]} // access to Test.this from wrong staging level
-      val r4 = '{summon[${T} <:< Any]}
+      val r1 = '{Option.empty[T.Underlying]} // works
+      val r2 = '{Option.empty[List[T.Underlying]]} // works
+      // val r3 = '{summon[Type[T.Underlying]]} // access to Test.this from wrong staging level
+      val r4 = '{summon[T.Underlying <:< Any]}
     }
 
     {
-      val s = '{Option.empty[${T}]}
+      val s = '{Option.empty[T.Underlying]}
       val r = '{identity($s)} // works
       val r2 = '{identity(${s: Expr[Option[T]]})}
     }

tests/pos-macros/i7405.scala

@@ -6,7 +6,7 @@ class Foo {
       val x: X = ???
       ${
         val t: Type[X] = '[X] // Level 0
-        '{ val y: $t = x }
+        '{ val y: t.Underlying = x }
       }
     }
   }

tests/pos-macros/i7405b.scala

@@ -11,7 +11,8 @@ class Foo {
       type Z = x.Y
       ${
         val t: Type[Z] = '[Z]
-        '{ val y: $t = x.y }
+        '{ val y: Z = x.y }
+        '{ val y: t.Underlying = x.y }
       }
     }
   }

tests/pos-macros/i7887.scala

@@ -1,7 +1,7 @@
 def typed[A](using t: quoted.Type[A], qctx: quoted.QuoteContext): Unit = {
   import qctx.reflect._
   '{
-    type T = $t
+    type T = A
     ${'{???}.cast[T]}
   }
 }

tests/pos-macros/i9020-b/Macro_1.scala

@@ -8,8 +8,8 @@ object Show {
   import quoted._
   def impl[T](using ctx: QuoteContext, tpe: Type[T]): Expr[Show[T]] =
     '{
-      new Show[$tpe] {
-        def show(t: $tpe): String = "TODO"
+      new Show[tpe.Underlying] {
+        def show(t: tpe.Underlying): String = "TODO"
       }
     }
 }

tests/pos-macros/quote-1.scala

@@ -3,13 +3,13 @@ import scala.quoted._
 class Test(using QuoteContext) {
 
   def f[T](x: Expr[T])(implicit t: Type[T]) = '{
-    val y: $t = $x
+    val y: T = $x
     val z = $x
   }
 
   f('{2})('[Int])
   f('{ true })('[Boolean])
 
   def g(es: Expr[String], t: Type[String]) =
-    f('{ ($es + "!") :: Nil })('[List[$t]])
+    f('{ ($es + "!") :: Nil })('[List[t.Underlying]])
 }

tests/run-macros/i7887/Macro_1.scala

@@ -3,7 +3,7 @@ def myMacroImpl(a: quoted.Expr[_])(using qctx: quoted.QuoteContext) = {
   def typed[A] = {
     implicit val t: quoted.Type[A] = a.unseal.tpe.widen.seal.asInstanceOf[quoted.Type[A]]
     '{
-      type T = $t
+      type T = A
       ${a.unseal.seal.cast[T]}
     }
   }

tests/run-macros/refined-selectable-macro/Macro_2.scala

@@ -14,10 +14,10 @@ object Macro2 {
   object Record extends SelectableRecordCompanion[Record] {
     import scala.quoted._
 
-    inline def apply[R <: Record](elems: (String, Any)*) : R = ${ applyImpl('elems, '[R]) }
+    inline def apply[R <: Record](elems: (String, Any)*) : R = ${ applyImpl[R]('elems) }
 
-    def applyImpl[R <: Record: Type](elems: Expr[Seq[(String, Any)]], ev: Type[R])(using qctx: QuoteContext) = {
-      '{ new Record($elems:_*).asInstanceOf[$ev] }
+    def applyImpl[R <: Record: Type](elems: Expr[Seq[(String, Any)]])(using qctx: QuoteContext) = {
+      '{ new Record($elems:_*).asInstanceOf[R] }
     }
 
     def fromUntypedTuple(elems: (String, Any)*): Record = Record(elems: _*)