diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/TypingTransformers.scala | 6 | ||||
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala | 160 |
2 files changed, 157 insertions, 9 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala index c4de6f6fab..ffab99ed26 100644 --- a/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala +++ b/src/compiler/scala/tools/nsc/transform/TypingTransformers.scala @@ -6,6 +6,8 @@ package scala.tools.nsc.transform +import scala.collection.mutable.{Map, HashMap} + /** A base class for transforms. * A transform contains a compiler phase which applies a tree transformer. */ @@ -19,13 +21,17 @@ trait TypingTransformers { analyzer.rootContext(unit, EmptyTree, true)) private var curTree: Tree = _ + var typers: Map[Symbol, analyzer.Typer] = new HashMap + override def atOwner[A](owner: Symbol)(trans: => A): A = atOwner(curTree, owner)(trans) def atOwner[A](tree: Tree, owner: Symbol)(trans: => A): A = { val savedLocalTyper = localTyper localTyper = localTyper.atOwner(tree, owner) + typers += owner -> localTyper; val result = super.atOwner(owner)(trans) localTyper = savedLocalTyper + typers.excl(owner); result } diff --git a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala index 42c03ab884..776425e2b7 100644 --- a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala +++ b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala @@ -21,7 +21,7 @@ import nsc.symtab.Flags._ * @author Martin Odersky * @version 1.0 */ -abstract class SuperAccessors extends transform.Transform { +abstract class SuperAccessors extends transform.Transform with transform.TypingTransformers { // inherits abstract value `global' and class `Phase' from Transform import global._ @@ -34,7 +34,7 @@ abstract class SuperAccessors extends transform.Transform { protected def newTransformer(unit: CompilationUnit): Transformer = new SuperAccTransformer(unit) - class SuperAccTransformer(unit: CompilationUnit) extends Transformer { + class SuperAccTransformer(unit: CompilationUnit) extends TypingTransformer(unit) { private var validCurrentOwner = true private var accDefs: List[Pair[Symbol, ListBuffer[Tree]]] = List() @@ -62,11 +62,13 @@ abstract class SuperAccessors extends transform.Transform { } super.transform(tree) case Template(parents, body) => - val ownAccDefs = new ListBuffer[Tree] - accDefs = Pair(currentOwner, ownAccDefs) :: accDefs; - val body1 = transformTrees(body) - accDefs = accDefs.tail - copy.Template(tree, parents, ownAccDefs.toList ::: body1) + val ownAccDefs = new ListBuffer[Tree]; + accDefs = Pair(currentOwner, ownAccDefs) :: accDefs; +// val body1 = transformTrees(body); + val Template(_, body1) = super.transform(tree); + accDefs = accDefs.tail; + copy.Template(tree, parents, ownAccDefs.toList ::: body1); + case Select(qual @ This(_), name) => val sym = tree.symbol if ((sym hasFlag PARAMACCESSOR) && (sym.alias != NoSymbol)) { @@ -78,7 +80,13 @@ abstract class SuperAccessors extends transform.Transform { if (settings.debug.value) System.out.println("alias replacement: " + tree + " ==> " + result);//debug transform(result) - } else tree + } else { + if (needsProtectedAccessor(sym, tree.pos)) { + if (settings.debug.value) log("Adding protected accessor for " + tree); + transform(makeAccessor(tree.asInstanceOf[Select])) + } else + tree + } case Select(sup @ Super(_, mix), name) => val sym = tree.symbol val clazz = sup.symbol @@ -107,6 +115,27 @@ abstract class SuperAccessors extends transform.Transform { Select(gen.mkAttributedThis(clazz), superAcc) setType tree.tpe; } } else tree + + case Select(qual, name) => + val sym = tree.symbol + if (needsProtectedAccessor(sym, tree.pos)) { + if (settings.debug.value) log("Adding protected accessor for tree: " + tree); + transform(makeAccessor(tree.asInstanceOf[Select])) + } else + super.transform(tree) + + case Assign(lhs @ Select(qual, name), rhs) => + if (lhs.symbol.isVariable && + lhs.symbol.hasFlag(JAVA) && + needsProtectedAccessor(lhs.symbol, tree.pos)) { + if (settings.debug.value) log("Adding protected setter for " + tree) + val setter = makeSetter(lhs); + if (settings.debug.value) + log("Replaced " + tree + " with " + setter); + transform(typed(Apply(setter, List(qual, rhs)))) + } else + super.transform(tree) + case Apply(fn, args) => copy.Apply(tree, transform(fn), transformArgs(args, fn.tpe.paramTypes)) case Function(vparams, body) => @@ -118,7 +147,7 @@ abstract class SuperAccessors extends transform.Transform { } override def atOwner[A](owner: Symbol)(trans: => A): A = { - if (owner.isClass) validCurrentOwner = true; + if (owner.isClass) validCurrentOwner = true super.atOwner(owner)(trans) } @@ -129,5 +158,118 @@ abstract class SuperAccessors extends transform.Transform { validCurrentOwner = prevValidCurrentOwner result } + + /** Add a protected accessor, if needed, and return a tree that calls + * the accessor and returns the the same member. The result is already + * typed. + */ + private def makeAccessor(tree: Select): Tree = { + val Select(qual, name) = tree + val sym = tree.symbol + val clazz = hostForAccessorOf(sym, currentOwner.enclClass) + assert(clazz != NoSymbol, sym) + if (settings.debug.value) + log("Decided for host class: " + clazz) + val accName = nme.protName(sym.originalName) + var protAcc = clazz.info.decl(accName) + if (protAcc == NoSymbol) { + val hasArgs = sym.tpe.paramTypes != Nil + + protAcc = clazz.newMethod(tree.pos, nme.protName(sym.originalName)) + .setInfo(MethodType(List(clazz.typeOfThis), + if (hasArgs) + MethodType(sym.tpe.paramTypes, sym.tpe.resultType) + else + sym.tpe.resultType)) + clazz.info.decls.enter(protAcc); + val code = DefDef(protAcc, vparamss => + vparamss.tail.foldRight(Select(gen.mkAttributedRef(vparamss.head.head), sym): Tree) ( + (vparams, fun) => Apply(fun, (vparams map { v => Ident(v) } )))) + if (settings.debug.value) + log(code) + accDefBuf(clazz) += typers(clazz).typed(code) + } + var res: Tree = atPos(tree.pos) { Apply(Select(This(clazz), protAcc), List(qual)) } + if (settings.debug.value) + log("Replaced " + tree + " with " + res) + typer.typedOperator(res) + } + + /** Add an accessor for field, if needed, and return a selection tree for it . + * The result is not typed. + */ + private def makeSetter(tree: Select): Tree = { + val field = tree.symbol + val clazz = hostForAccessorOf(field, currentOwner.enclClass) + assert(clazz != NoSymbol, field) + if (settings.debug.value) + log("Decided for host class: " + clazz) + val accName = nme.protSetterName(field.originalName) + var protAcc = clazz.info.decl(accName) + if (protAcc == NoSymbol) { + protAcc = clazz.newMethod(field.pos, nme.protSetterName(field.originalName)) + .setInfo(MethodType(List(clazz.typeOfThis, field.tpe), definitions.UnitClass.tpe)); + clazz.info.decls.enter(protAcc) + val code = DefDef(protAcc, vparamss => { + val obj :: value :: Nil = vparamss.head; + atPos(tree.pos) { + Assign( + Select(Ident(obj), field.name), + Ident(value)) + } + }) + if (settings.debug.value) + log(code); + accDefBuf(clazz) += typers(clazz).typed(code) + } + var res: Tree = atPos(tree.pos) { Select(This(clazz), protAcc) } + res + } + + /** Does `sym' need an accessor when accessed from `currentOwner'? + * A special case arises for classes with explicit self-types. If the + * self type is a Java class, and a protected accessor is needed, we issue + * an error. If the self type is a Scala class, we don't add an accessor. + * + * If the access happens inside a 'trait', access is more problematic since + * the implementation code is moved to an '$class' class which does not + * inherit anything. Since we can't (yet) add accessors for 'required' + * classes, this has to be signaled as error. + */ + private def needsProtectedAccessor(sym: Symbol, pos: PositionType): Boolean = { + val res = /* settings.debug.value && */ + ((sym hasFlag PROTECTED) + && (!(currentOwner.enclClass.thisSym isSubClass sym.owner)) + && (enclPackage(sym.owner) != enclPackage(currentOwner))) + + if (res) { + val host = hostForAccessorOf(sym, currentOwner.enclClass) + if (host.thisSym != host) { + if (host.thisSym.tpe.symbol.hasFlag(JAVA) || currentOwner.enclClass.isTrait) + unit.error(pos, "Implementation restriction: " + currentOwner.enclClass + " accesses protected " + + sym + " from 'required' " + host.thisSym.tpe) + false + } else res + } else res + } + + /** Return the enclosing package of the given symbol. */ + private def enclPackage(sym: Symbol): Symbol = + if ((sym == NoSymbol) || sym.isPackageClass) sym else enclPackage(sym.owner) + + /** Return the innermost enclosing class C of referencingClass for which either + * of the following holds: + * - C is a subclass of sym.owner or + * - C is declared in the same package as sym's owner + */ + private def hostForAccessorOf(sym: Symbol, referencingClass: Symbol): Symbol = { + if (referencingClass.isSubClass(sym.owner.enclClass) + || referencingClass.thisSym.isSubClass(sym.owner.enclClass) + || enclPackage(referencingClass) == enclPackage(sym.owner)) { + assert(referencingClass.isClass) + referencingClass + } else + hostForAccessorOf(sym, referencingClass.owner.enclClass) + } } } |