Merge pull request #9098 from dotty-staging/scala2-macro-bundle-val

nicolasstucki · web-flow · commit 31879e5a4647 · 2020-06-06T09:43:55.000+02:00
Add a val in Scala 2 macro bundles
diff --git a/compiler/src/dotty/tools/dotc/core/StdNames.scala b/compiler/src/dotty/tools/dotc/core/StdNames.scala
@@ -425,6 +425,7 @@ object StdNames {
     val assume_ : N             = "assume"
     val box: N                  = "box"
     val build : N               = "build"
+    val bundle: N               = "bundle"
     val bytes: N                = "bytes"
     val canEqual_ : N           = "canEqual"
     val cbnArg: N               = "<cbn-arg>"
diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala
@@ -3566,28 +3566,34 @@ class Typer extends Namer
   /** Types the body Scala 2 macro declaration `def f = macro <body>` */
   private def typedScala2MacroBody(call: untpd.Tree)(using Context): Tree =
     // TODO check that call is to a method with valid signature
-    def typedPrefix(tree: untpd.RefTree): Tree = {
+    def typedPrefix(tree: untpd.RefTree)(splice: Context ?=> Tree => Tree)(using Context): Tree = {
       tryAlternatively {
-        typedExpr(tree, defn.AnyType)
+        splice(typedExpr(tree, defn.AnyType))
       } {
         // Try to type as a macro bundle
         val ref = tree match
           case Ident(name) => untpd.Ident(name.toTypeName).withSpan(tree.span)
           case Select(qual, name) => untpd.Select(qual, name.toTypeName).withSpan(tree.span)
         val bundle = untpd.Apply(untpd.Select(untpd.New(ref), nme.CONSTRUCTOR), untpd.Literal(Constant(null))).withSpan(call.span)
-        typedExpr(bundle, defn.AnyType)
+        val bundle1 = typedExpr(bundle, defn.AnyType)
+        val bundleVal = SyntheticValDef(NameKinds.UniqueName.fresh(nme.bundle), bundle1).withSpan(call.span)
+        tpd.Block(List(bundleVal), splice(tpd.ref(bundleVal.symbol))).withSpan(call.span)
       }
     }
     if ctx.phase.isTyper then
       call match
         case call: untpd.Ident =>
           typedIdent(call, defn.AnyType)
         case untpd.Select(qual: untpd.RefTree, name) =>
-          val call2 = untpd.Select(untpd.TypedSplice(typedPrefix(qual)), name).withSpan(call.span)
-          typedSelect(call2, defn.AnyType)
+          typedPrefix(qual) { qual =>
+            val call2 = untpd.Select(untpd.TypedSplice(qual), name).withSpan(call.span)
+            typedSelect(call2, defn.AnyType)
+          }
         case untpd.TypeApply(untpd.Select(qual: untpd.RefTree, name), targs) =>
-          val call2= untpd.TypeApply(untpd.Select(untpd.TypedSplice(typedPrefix(qual)), name), targs).withSpan(call.span)
-          typedTypeApply(call2, defn.AnyType)
+          typedPrefix(qual) { qual =>
+            val call2 = untpd.TypeApply(untpd.Select(untpd.TypedSplice(qual), name), targs).withSpan(call.span)
+            typedTypeApply(call2, defn.AnyType)
+          }
         case _ =>
           ctx.error("Invalid Scala 2 macro " + call.show, call.sourcePos)
           EmptyTree
