@@ -14,21 +14,21 @@ import Annotations._
1414import StdNames ._
1515import NameOps ._
1616import NameKinds .{ExpandedName , TraitSetterName }
17+ import ast .Trees ._
1718
1819object AugmentScala2Traits {
1920 val name : String = " augmentScala2Traits"
2021}
2122
22- /** This phase augments Scala2 traits with implementation classes and with additional members
23- * needed for mixin composition.
24- * These symbols would have been added between Unpickling and Mixin in the Scala2 pipeline.
25- * Specifically, it adds
23+ /** This phase augments Scala2 traits with additional members needed for mixin composition.
2624 *
27- * - an implementation class which defines a trait constructor and trait method implementations
28- * - trait setters for vals defined in traits
25+ * These symbols would have been added between Unpickling and Mixin in the Scala2 pipeline.
2926 *
30- * Furthermore, it expands the names of all private getters and setters as well as super accessors in the trait and makes
31- * them not-private.
27+ * Specifically, we:
28+ * - Mark all lazy val fields as @volatile to get the proper Scala 2 semantics.
29+ * - Add trait setters for vals defined in traits.
30+ * - Expand the names of all private getters and setters as well as super accessors in the trait and make
31+ * not-private.
3232 */
3333class AugmentScala2Traits extends MiniPhase with IdentityDenotTransformer with FullParameterization { thisPhase =>
3434 import ast .tpd ._
@@ -41,66 +41,34 @@ class AugmentScala2Traits extends MiniPhase with IdentityDenotTransformer with F
4141
4242 override def transformTemplate (impl : Template )(implicit ctx : Context ): Template = {
4343 val cls = impl.symbol.owner.asClass
44- for (mixin <- cls.mixins)
45- if (mixin.is(Scala2x ))
46- augmentScala2Trait(mixin, cls)
44+ for (mixin <- cls.mixins if mixin.is(Scala2x ) && ! mixin.is(Scala2xPartiallyAugmented ))
45+ augmentScala2Trait(mixin)
4746 impl
4847 }
4948
50- private def augmentScala2Trait (mixin : ClassSymbol , cls : ClassSymbol )(implicit ctx : Context ): Unit = {
51- if (mixin.implClass.is(Scala2x )) () // nothing to do, mixin was already augmented
52- else {
53- // println(i"creating new implclass for $mixin ${mixin.implClass}")
54- val ops = new MixinOps (cls, thisPhase)
55- import ops ._
56-
57- val implClass = ctx.newCompleteClassSymbol(
58- owner = mixin.owner,
59- name = mixin.name.implClassName,
60- flags = Abstract | Scala2x | ImplClass ,
61- parents = defn.ObjectType :: Nil ,
62- assocFile = mixin.assocFile).enteredAfter(thisPhase)
63-
64- def implMethod (meth : TermSymbol ): Symbol = {
65- val mold =
66- if (meth.isConstructor)
67- meth.copySymDenotation(
68- name = nme.TRAIT_CONSTRUCTOR ,
69- info = MethodType (Nil , defn.UnitType ))
70- else meth.ensureNotPrivate
71- meth.copy(
72- owner = implClass,
73- name = mold.name.asTermName,
74- flags = Method | JavaStatic ,
75- info = fullyParameterizedType(mold.info, mixin))
76- }
77-
78- def traitSetter (getter : TermSymbol ) =
79- getter.copy(
80- name = getter.ensureNotPrivate.name
81- .expandedName(getter.owner, TraitSetterName )
82- .asTermName.setterName,
83- flags = Method | Accessor ,
84- info = MethodType (getter.info.resultType :: Nil , defn.UnitType ))
49+ private def augmentScala2Trait (mixin : ClassSymbol )(implicit ctx : Context ): Unit = {
50+ def traitSetter (getter : TermSymbol ) =
51+ getter.copy(
52+ name = getter.ensureNotPrivate.name
53+ .expandedName(getter.owner, TraitSetterName )
54+ .asTermName.setterName,
55+ flags = Method | Accessor ,
56+ info = MethodType (getter.info.resultType :: Nil , defn.UnitType ))
8557
86- for (sym <- mixin.info.decls) {
87- if (needsForwarder(sym) || sym.isConstructor || sym.isGetter && sym.is(Lazy ) || sym.is(Method , butNot = Deferred ))
88- implClass.enter(implMethod(sym.asTerm))
89- if (sym.isGetter)
90- if (sym.is(Lazy )) {
91- if (! sym.hasAnnotation(defn.VolatileAnnot ))
92- sym.addAnnotation(Annotation (defn.VolatileAnnot , Nil ))
93- }
94- else if (! sym.is(Deferred ) && ! sym.setter.exists &&
95- ! sym.info.resultType.isInstanceOf [ConstantType ])
96- traitSetter(sym.asTerm).enteredAfter(thisPhase)
97- if ((sym.is(PrivateAccessor ) && ! sym.name.is(ExpandedName ) &&
98- (sym.isGetter || sym.isSetter)) // strangely, Scala 2 fields are also methods that have Accessor set.
99- || sym.isSuperAccessor) // scala2 superaccessors are pickled as private, but are compiled as public expanded
100- sym.ensureNotPrivate.installAfter(thisPhase)
101- }
102- ctx.log(i " Scala2x trait decls of $mixin = ${mixin.info.decls.toList.map(_.showDcl)}% \n % " )
103- ctx.log(i " Scala2x impl decls of $mixin = ${implClass.info.decls.toList.map(_.showDcl)}% \n % " )
58+ for (sym <- mixin.info.decls) {
59+ if (sym.isGetter)
60+ if (sym.is(Lazy )) {
61+ if (! sym.hasAnnotation(defn.VolatileAnnot ))
62+ sym.addAnnotation(Annotation (defn.VolatileAnnot , Nil ))
63+ }
64+ else if (! sym.is(Deferred ) && ! sym.setter.exists &&
65+ ! sym.info.resultType.isInstanceOf [ConstantType ])
66+ traitSetter(sym.asTerm).enteredAfter(thisPhase)
67+ if ((sym.is(PrivateAccessor ) && ! sym.name.is(ExpandedName ) &&
68+ (sym.isGetter || sym.isSetter)) // strangely, Scala 2 fields are also methods that have Accessor set.
69+ || sym.isSuperAccessor) // scala2 superaccessors are pickled as private, but are compiled as public expanded
70+ sym.ensureNotPrivate.installAfter(thisPhase)
10471 }
72+ mixin.setFlag(Scala2xPartiallyAugmented )
10573 }
10674}
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