diff options
Diffstat (limited to 'src')
7 files changed, 22 insertions, 3 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/Constructors.scala b/src/compiler/scala/tools/nsc/transform/Constructors.scala index 636fb08b89..971a55f763 100644 --- a/src/compiler/scala/tools/nsc/transform/Constructors.scala +++ b/src/compiler/scala/tools/nsc/transform/Constructors.scala @@ -715,6 +715,9 @@ abstract class Constructors extends Statics with Transform with ast.TreeDSL { primaryConstrBody.expr) }) + if (omittableAccessor.exists(_.isOuterField) && !constructorStats.exists(_.exists { case i: Ident if i.symbol.isOuterParam => true; case _ => false})) + primaryConstructor.symbol.updateAttachment(OuterArgCanBeElided) + val constructors = primaryConstructor :: auxConstructors // Unlink all fields that can be dropped from class scope diff --git a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala index a8933a9ee6..2dd8def53e 100644 --- a/src/compiler/scala/tools/nsc/transform/Delambdafy.scala +++ b/src/compiler/scala/tools/nsc/transform/Delambdafy.scala @@ -279,10 +279,15 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre if (!dd.symbol.hasFlag(STATIC) && !methodReferencesThis(dd.symbol)) dd.symbol.setFlag(STATIC) super.transform(tree) + case Apply(fun, outer :: rest) if shouldElideOuterArg(fun.symbol, outer) => + val nullOuter = gen.mkZero(outer.tpe) + treeCopy.Apply(tree, transform(fun), nullOuter :: transformTrees(rest)) case _ => super.transform(tree) } } // DelambdafyTransformer + private def shouldElideOuterArg(fun: Symbol, outerArg: Tree): Boolean = + fun.isConstructor && treeInfo.isQualifierSafeToElide(outerArg) && fun.hasAttachment[OuterArgCanBeElided.type] // A traverser that finds symbols used but not defined in the given Tree // TODO freeVarTraverser in LambdaLift does a very similar task. With some @@ -368,6 +373,9 @@ abstract class Delambdafy extends Transform with TypingTransformers with ast.Tre case Apply(sel @ Select(This(_), _), args) if sel.symbol.isLiftedMethod => if (currentMethod.exists) liftedMethodReferences(currentMethod) += sel.symbol super.traverseTrees(args) + case Apply(fun, outer :: rest) if shouldElideOuterArg(fun.symbol, outer) => + super.traverse(fun) + super.traverseTrees(rest) case This(_) => if (currentMethod.exists && tree.symbol == currentMethod.enclClass) { debuglog(s"$currentMethod directly refers to 'this'") diff --git a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala index 3d6fad4238..411ff6b9be 100644 --- a/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala +++ b/src/compiler/scala/tools/nsc/transform/ExplicitOuter.scala @@ -67,8 +67,6 @@ abstract class ExplicitOuter extends InfoTransform result } - private val innerClassConstructorParamName: TermName = newTermName("arg" + nme.OUTER) - class RemoveBindingsTransformer(toRemove: Set[Symbol]) extends Transformer { override def transform(tree: Tree) = tree match { case Bind(_, body) if toRemove(tree.symbol) => super.transform(body) @@ -169,7 +167,7 @@ abstract class ExplicitOuter extends InfoTransform val paramsWithOuter = if (sym.isClassConstructor && isInner(sym.owner)) // 1 - sym.newValueParameter(innerClassConstructorParamName, sym.pos).setInfo(sym.owner.outerClass.thisType) :: params + sym.newValueParameter(nme.OUTER_ARG, sym.pos).setInfo(sym.owner.outerClass.thisType) :: params else params if ((resTpTransformed ne resTp) || (paramsWithOuter ne params)) MethodType(paramsWithOuter, resTpTransformed) diff --git a/src/reflect/scala/reflect/internal/StdAttachments.scala b/src/reflect/scala/reflect/internal/StdAttachments.scala index ef95b38843..76e34153c9 100644 --- a/src/reflect/scala/reflect/internal/StdAttachments.scala +++ b/src/reflect/scala/reflect/internal/StdAttachments.scala @@ -71,4 +71,9 @@ trait StdAttachments { abstract class InlineAnnotatedAttachment case object NoInlineCallsiteAttachment extends InlineAnnotatedAttachment case object InlineCallsiteAttachment extends InlineAnnotatedAttachment + + /** Attached to a local class that has its outer field elided. A `null` constant may be passed + * in place of the outer parameter, can help callers to avoid capturing the outer instance. + */ + case object OuterArgCanBeElided extends PlainAttachment } diff --git a/src/reflect/scala/reflect/internal/StdNames.scala b/src/reflect/scala/reflect/internal/StdNames.scala index c93ecac3fa..d96d06ca94 100644 --- a/src/reflect/scala/reflect/internal/StdNames.scala +++ b/src/reflect/scala/reflect/internal/StdNames.scala @@ -364,6 +364,7 @@ trait StdNames { val MODULE_INSTANCE_FIELD: NameType = NameTransformer.MODULE_INSTANCE_NAME // "MODULE$" val OUTER: NameType = "$outer" val OUTER_LOCAL: NameType = OUTER.localName + val OUTER_ARG: NameType = "arg" + OUTER val OUTER_SYNTH: NameType = "<outer>" // emitted by virtual pattern matcher, replaced by outer accessor in explicitouter val ROOTPKG: NameType = "_root_" val SELECTOR_DUMMY: NameType = "<unapply-selector>" diff --git a/src/reflect/scala/reflect/internal/Symbols.scala b/src/reflect/scala/reflect/internal/Symbols.scala index 3b886d357f..e2fb827186 100644 --- a/src/reflect/scala/reflect/internal/Symbols.scala +++ b/src/reflect/scala/reflect/internal/Symbols.scala @@ -914,6 +914,9 @@ trait Symbols extends api.Symbols { self: SymbolTable => /** Is this symbol an accessor method for outer? */ final def isOuterField = isArtifact && (unexpandedName == nme.OUTER_LOCAL) + /** Is this symbol an outer parameter in a constructor */ + final def isOuterParam = isParameter && owner.isConstructor && (name == nme.OUTER_ARG || name == nme.OUTER) + /** Does this symbol denote a stable value, ignoring volatility? * * Stability and volatility are checked separately to allow volatile paths in patterns that amount to equality checks. SI-6815 diff --git a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala index 28222cf9a7..0a90a141d3 100644 --- a/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala +++ b/src/reflect/scala/reflect/runtime/JavaUniverseForce.scala @@ -45,6 +45,7 @@ trait JavaUniverseForce { self: runtime.JavaUniverse => this.SubpatternsAttachment this.NoInlineCallsiteAttachment this.InlineCallsiteAttachment + this.OuterArgCanBeElided this.noPrint this.typeDebug this.Range |