Merge pull request #5273 from tuvior/decompiler-varargs

Resugar Varargs

Author: nicolasstucki

compiler/test/dotc/pos-recompilation.whitelist

@@ -38,3 +38,5 @@ t116
 t3869
 t6225b
 t704
+varargs
+varargs-position

library/src/scala/tasty/util/ShowSourceCode.scala

@@ -344,7 +344,13 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
       case Term.Typed(term, tpt) =>
         tpt.tpe match {
           case Types.Repeated(_) =>
-            printTree(term)
+            term match {
+              case Term.Repeated(_) =>
+                printTree(term)
+              case _ =>
+                printTree(term)
+                this += ": " += highlightTypeDef("_*", color)
+            }
           case _ =>
             inParens {
               printTree(term)
@@ -790,9 +796,16 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
 
       case TypeTree.Annotated(tpt, annot) =>
         val Annotation(ref, args) = annot
-        printTypeTree(tpt)
-        this += " "
-        printAnnotation(annot)
+        ref.tpe match {
+          case Types.RepeatedAnnotation() =>
+            val Types.Sequence(tp) = tpt.tpe
+            printType(tp)
+            this += highlightTypeDef("*", color)
+          case _ =>
+            printTypeTree(tpt)
+            this += " "
+            printAnnotation(annot)
+        }
 
       case TypeTree.And(left, right) =>
         printTypeTree(left)
@@ -1160,6 +1173,20 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
       }
     }
 
+    object Sequence {
+      def unapply(tpe: Type)(implicit ctx: Context): Option[Type] = tpe match {
+        case Type.AppliedType(Type.TypeRef("Seq", Type.SymRef(sym, _)), IsType(tp) :: Nil) if sym.fullName == "scala.collection" => Some(tp)
+        case _ => None
+      }
+    }
+
+    object RepeatedAnnotation {
+      def unapply(tpe: Type)(implicit ctx: Context): Boolean = tpe match {
+        case Type.TypeRef("Repeated", Type.SymRef(sym, _)) if sym.fullName == "scala.annotation.internal" => true
+        case _ => false
+      }
+    }
+
     object Repeated {
       def unapply(tpe: Type)(implicit ctx: Context): Option[Type] = tpe match {
         case Type.AppliedType(Type.TypeRef("<repeated>", ScalaPackage()), IsType(tp) :: Nil) => Some(tp)

tests/pos/varargs-position.decompiled

@@ -0,0 +1,12 @@
+object varargspos {
+  def g(a: scala.Int, x: scala.Int*): scala.Int = a.+(x.length)
+  varargspos.g(1, 2, 3, 4)
+  val xs: collection.immutable.List[scala.Int] = scala.Nil.::[scala.Int](2).::[scala.Int](1)
+  val a: scala.Int = 8
+  val b: scala.Int = 7
+  varargspos.g(5, varargspos.xs: _*)
+  varargspos.g(3, scala.Nil: _*)
+  varargspos.g(varargspos.a, varargspos.xs: _*)
+  varargspos.g(varargspos.a, varargspos.b, 2, 3)
+  varargspos.g(1)
+}

tests/pos/varargs-position.scala

@@ -0,0 +1,12 @@
+object varargspos {
+  def g(a: Int, x: Int*) = a + x.length
+  g(1, 2, 3, 4)
+  val xs = 1 :: 2 :: Nil
+  val a = 8
+  val b = 7
+  g(5, xs: _*)
+  g(3, Nil: _*)
+  g(a, xs: _*)
+  g(a, b, 2, 3)
+  g(1)
+}