Merge pull request #7667 from dotty-staging/fix-#7603

Fix #7603: Emit error when a splice type is not an identifier

Author: nicolasstucki

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

@@ -107,9 +107,9 @@ trait QuotesAndSplices {
           if (ctx.mode.is(Mode.QuotedPattern)) spliceOwner(ctx.outer) else ctx.owner
         val name = tree.expr match {
           case Ident(name) => ("$" + name).toTypeName
-          case Typed(Ident(name), _) => ("$" + name).toTypeName
-          case Bind(name, _) => ("$" + name).toTypeName
-          case _ => NameKinds.UniqueName.fresh("$".toTypeName)
+          case expr =>
+            ctx.error("expected a name binding", expr.sourcePos)
+            "$error".toTypeName
         }
         val typeSym = ctx.newSymbol(spliceOwner(ctx), name, EmptyFlags, TypeBounds.empty, NoSymbol, tree.expr.span)
         typeSym.addAnnotation(Annotation(New(ref(defn.InternalQuoted_patternBindHoleAnnot.typeRef)).withSpan(tree.expr.span)))
@@ -233,7 +233,6 @@ trait QuotesAndSplices {
           tdef.symbol.addAnnotation(Annotation(New(ref(defn.InternalQuoted_fromAboveAnnot.typeRef)).withSpan(tdef.span)))
         val bindingType = getBinding(tdef.symbol).symbol.typeRef
         val bindingTypeTpe = AppliedType(defn.QuotedTypeClass.typeRef, bindingType :: Nil)
-        assert(tdef.name.startsWith("$"))
         val bindName = tdef.name.toString.stripPrefix("$").toTermName
         val sym = ctx0.newPatternBoundSymbol(bindName, bindingTypeTpe, tdef.span, flags = ImplicitTerm)
         buff += Bind(sym, untpd.Ident(nme.WILDCARD).withType(bindingTypeTpe)).withSpan(tdef.span)

tests/neg/i7603.scala

@@ -0,0 +1,7 @@
+import scala.quoted._
+class Foo {
+  def f[T2: Type](e: Expr[T2])(given QuoteContext) = e match {
+    case '{ $x: ${'[List[$t]]} } => // error
+    case '{ $x: ${y @ '[List[$t]]} } => // error // error
+  }
+}

tests/neg/quotedPatterns-6.scala

@@ -0,0 +1,12 @@
+import scala.quoted._
+object Test {
+  def test(x: quoted.Expr[Int])(given QuoteContext) = x match {
+    case '{ poly[${Foo(t)}]($x); 4 } => ??? // error
+    case '{ type $t; poly[${Foo(y: quoted.Type[`$t`])}]($x); 4 } => ??? // error
+    case _ =>
+  }
+
+  def poly[T](x: T): Unit = ()
+
+}
+

tests/pos/quotedPatterns.scala

@@ -32,9 +32,7 @@ object Test {
       val a: quoted.matching.Sym[[T] =>> T => Int] = ff
       z
     case '{ poly[$t]($x); 4 } => ???
-    case '{ poly[${Foo(t)}]($x); 4 } => ???
     case '{ type $X; poly[`$X`]($x); 4 } => ???
-    case '{ type $t; poly[${Foo(x: quoted.Type[`$t`])}]($x); 4 } => ???
     case '{ type $T; val x: `$T` = $a; val y: `$T` = x;  1 } => ???
     case '{ type $t <: AnyRef; val x: `$t` = $a; val y: `$t` = x;  1 } => ???
     case _ => '{1}