1 files changed, 76 insertions, 0 deletions
diff --git a/compiler/src/dotty/tools/dotc/transform/Getters.scala b/compiler/src/dotty/tools/dotc/transform/Getters.scala
new file mode 100644
index 000000000..31171dfab
--- /dev/null
+++ b/compiler/src/dotty/tools/dotc/transform/Getters.scala
@@ -0,0 +1,76 @@
+package dotty.tools.dotc
+package transform
+
+import core._
+import DenotTransformers.SymTransformer
+import Contexts.Context
+import SymDenotations.SymDenotation
+import Types._
+import Symbols._
+import SymUtils._
+import Constants._
+import TreeTransforms._
+import Flags._
+import Decorators._
+import ValueClasses._
+
+/** Performs the following rewritings for fields of a class:
+ *
+ *    <mods> val x: T = e
+ *      -->  <mods> <stable> <accessor> def x: T = e
+ *    <mods> var x: T = e
+ *      -->  <mods> <accessor> def x: T = e
+ *
+ *    <mods> val x: T
+ *      -->  <mods> <stable> <accessor> def x: T
+ *
+ *    <mods> lazy val x: T = e
+ *      -->  <mods> <accessor> lazy def x: T =e
+ *
+ *    <mods> var x: T
+ *      -->  <mods> <accessor> def x: T
+ *
+ *    <mods> non-static <module> val x$ = e
+ *      -->  <mods> <module> <accessor> def x$ = e
+ *
+ *  Omitted from the rewritings are
+ *
+ *   - private[this] fields in classes (excluding traits, value classes)
+ *   - fields generated for static modules (TODO: needed?)
+ *   - parameters, static fields, and fields coming from Java
+ *
+ *  Furthermore, assignments to mutable vars are replaced by setter calls
+ *
+ *     p.x = e
+ *      -->  p.x_=(e)
+ *
+ *  No fields are generated yet. This is done later in phase Memoize.
+ */
+class Getters extends MiniPhaseTransform with SymTransformer { thisTransform =>
+  import ast.tpd._
+
+  override def phaseName = "getters"
+
+  override def transformSym(d: SymDenotation)(implicit ctx: Context): SymDenotation = {
+    def noGetterNeeded =
+      d.is(NoGetterNeeded) ||
+      d.initial.asInstanceOf[SymDenotation].is(PrivateLocal) && !d.owner.is(Trait) && !isDerivedValueClass(d.owner) && !d.is(Flags.Lazy) ||
+      d.is(Module) && d.isStatic ||
+      d.hasAnnotation(defn.ScalaStaticAnnot) ||
+      d.isSelfSym
+    if (d.isTerm && (d.is(Lazy) || d.owner.isClass) && d.info.isValueType && !noGetterNeeded) {
+      val maybeStable = if (d.isStable) Stable else EmptyFlags
+      d.copySymDenotation(
+        initFlags = d.flags | maybeStable | AccessorCreationFlags,
+        info = ExprType(d.info))
+    }
+    else d
+  }
+  private val NoGetterNeeded = Method | Param | JavaDefined | JavaStatic
+
+  override def transformValDef(tree: ValDef)(implicit ctx: Context, info: TransformerInfo): Tree =
+    if (tree.symbol is Method) DefDef(tree.symbol.asTerm, tree.rhs).withPos(tree.pos) else tree
+
+  override def transformAssign(tree: Assign)(implicit ctx: Context, info: TransformerInfo): Tree =
+    if (tree.lhs.symbol is Method) tree.lhs.becomes(tree.rhs).withPos(tree.pos) else tree
+}