Merge pull request #4780 from dotty-staging/fix-#4774

Disallow inferred splices and set the correct position

Author: smarter

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

@@ -568,8 +568,7 @@ class ReifyQuotes extends MacroTransformWithImplicits with InfoTransformer {
             quotation(quotedTree, tree)
           case tree: TypeTree if tree.tpe.typeSymbol.isSplice =>
             val splicedType = tree.tpe.stripTypeVar.asInstanceOf[TypeRef].prefix.termSymbol
-            if (levelOf.get(splicedType).contains(level)) tree
-            else splice(ref(splicedType).select(tpnme.UNARY_~))
+            splice(ref(splicedType).select(tpnme.UNARY_~).withPos(tree.pos))
           case tree: Select if tree.symbol.isSplice =>
             splice(tree)
           case tree: RefTree if isCaptured(tree.symbol, level) =>

tests/neg/i4774a.scala

@@ -0,0 +1,11 @@
+
+import scala.quoted._
+
+object Test {
+  def loop[T](x: Expr[T])(implicit t: Type[T]): Expr[T] = '{
+    val y: ~t = ~x
+    ~loop( // error: inferred loop[~t] where T should be used
+      '(y)
+    )
+  }
+}

tests/pos/i4774c.scala

@@ -0,0 +1,6 @@
+
+import scala.quoted._
+
+object Test {
+  def loop[T](x: Expr[T])(implicit t: Type[T]): Expr[T] = '{ val y = ~x; ~loop('(y)) }
+}

tests/pos/i4774.scala renamed to tests/pos/i4774d.scala

@@ -3,5 +3,5 @@ import scala.quoted._
 
 object Test {
   def loop[T](x: Expr[T])(implicit t: Type[T]): Expr[T] =
-    '{ val y: ~t = ~x; ~loop('(y)) }
+    '{ val y: T = ~x; ~loop('(y)) }
 }