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Diffstat (limited to 'src/compiler/scala/tools/nsc/ast/Reifiers.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/ast/Reifiers.scala | 761 |
1 files changed, 0 insertions, 761 deletions
diff --git a/src/compiler/scala/tools/nsc/ast/Reifiers.scala b/src/compiler/scala/tools/nsc/ast/Reifiers.scala deleted file mode 100644 index 7ece8bbd31..0000000000 --- a/src/compiler/scala/tools/nsc/ast/Reifiers.scala +++ /dev/null @@ -1,761 +0,0 @@ -/* NSC -- new Scala compiler - * Copyright 2005-2011 LAMP/EPFL - * @author Gilles Dubochet - */ - -package scala.tools.nsc -package ast - -import symtab._ -import Flags._ -import scala.reflect.api.Modifier._ -import scala.collection.{ mutable, immutable } -import scala.collection.mutable.ListBuffer -import scala.tools.nsc.util.FreshNameCreator -import scala.runtime.ScalaRunTime.{ isAnyVal, isTuple } - -/** Given a tree or type, generate a tree that when executed at runtime produces the original tree or type. - * See more info in the comments to `reify' in scala.reflect.macro.Context. - * - * @author Martin Odersky - * @version 2.10 - */ -trait Reifiers { self: Global => - - def reify(tree: Tree): Tree = { - class Reifier { - import definitions._ - import Reifier._ - - final val scalaPrefix = "scala." - final val localPrefix = "$local" - final val memoizerName = "$memo" - - val reifyDebug = settings.Yreifydebug.value - - private val reifiableSyms = mutable.ArrayBuffer[Symbol]() // the symbols that are reified with the tree - private val symIndex = mutable.HashMap[Symbol, Int]() // the index of a reifiable symbol in `reifiableSyms` - private var boundSyms = Set[Symbol]() // set of all symbols that are bound in tree to be reified - - private def definedInLiftedCode(tpe: Type) = - tpe exists (tp => boundSyms contains tp.typeSymbol) - - private def definedInLiftedCode(sym: Symbol) = - boundSyms contains sym - - /** - * Generate tree of the form - * - * { val $mr = scala.reflect.runtime.Mirror - * $local1 = new TypeSymbol(owner1, NoPosition, name1) - * ... - * $localN = new TermSymbol(ownerN, NoPositiion, nameN) - * $local1.setInfo(tpe1) - * ... - * $localN.setInfo(tpeN) - * $localN.setAnnotations(annotsN) - * rtree - * } - * - * where - * - * - `$localI` are free type symbols in the environment, as well as local symbols - * of refinement types. - * - `tpeI` are the info's of `symI` - * - `rtree` is code that generates `data` at runtime, maintaining all attributes. - * - `data` is typically a tree or a type. - */ - def reifyTopLevel(data: Any): Tree = { - val rtree = reify(data) - Block(mirrorAlias :: reifySymbolTableSetup, rtree) - } - - private def isLocatable(sym: Symbol) = - sym.isPackageClass || sym.owner.isClass || sym.isTypeParameter && sym.paramPos >= 0 - - private def registerReifiableSymbol(sym: Symbol): Unit = - if (!(symIndex contains sym)) { - sym.owner.ownersIterator find (x => !isLocatable(x)) foreach registerReifiableSymbol - symIndex(sym) = reifiableSyms.length - reifiableSyms += sym - } - - // helper methods - - private def localName(sym: Symbol): TermName = - newTermName(localPrefix + symIndex(sym)) - - private def call(fname: String, args: Tree*): Tree = - Apply(termPath(fname), args.toList) - - private def mirrorSelect(name: String): Tree = - termPath(nme.MIRROR_PREFIX + name) - - private def mirrorCall(name: TermName, args: Tree*): Tree = - call("" + (nme.MIRROR_PREFIX append name), args: _*) - - private def mirrorCall(name: String, args: Tree*): Tree = - call(nme.MIRROR_PREFIX + name, args: _*) - - private def mirrorFactoryCall(value: Product, args: Tree*): Tree = - mirrorFactoryCall(value.productPrefix, args: _*) - - private def mirrorFactoryCall(prefix: String, args: Tree*): Tree = - mirrorCall(prefix, args: _*) - - private def scalaFactoryCall(name: String, args: Tree*): Tree = - call(scalaPrefix + name + ".apply", args: _*) - - private def mkList(args: List[Tree]): Tree = - scalaFactoryCall("collection.immutable.List", args: _*) - - private def reifyModifiers(m: Modifiers) = - mirrorCall("modifiersFromInternalFlags", reify(m.flags), reify(m.privateWithin), reify(m.annotations)) - - private def reifyAggregate(name: String, args: Any*) = - scalaFactoryCall(name, (args map reify).toList: _*) - - /** - * Reify a list - */ - private def reifyList(xs: List[Any]): Tree = - mkList(xs map reify) - - /** - * Reify an array - */ - private def reifyArray(xs: Array[_]): Tree = - // @xeno.by: doesn't work for Array(LiteralAnnotArg(...)) - // because we cannot generate manifests for path-dependent types - scalaFactoryCall(nme.Array, xs map reify: _*) - - /** Reify a name */ - private def reifyName(name: Name) = - mirrorCall(if (name.isTypeName) "newTypeName" else "newTermName", Literal(Constant(name.toString))) - - private def isFree(sym: Symbol) = - !(symIndex contains sym) - - /** - * Reify a reference to a symbol - */ - private def reifySymRef(sym: Symbol): Tree = { - symIndex get sym match { - case Some(idx) => - Ident(localName(sym)) - case None => - if (sym == NoSymbol) - mirrorSelect("NoSymbol") - else if (sym == RootPackage) - mirrorSelect("definitions.RootPackage") - else if (sym == RootClass) - mirrorSelect("definitions.RootClass") - else if (sym == EmptyPackage) - mirrorSelect("definitions.EmptyPackage") - else if (sym.isModuleClass) - Select(reifySymRef(sym.sourceModule), "moduleClass") - else if (sym.isStatic && sym.isClass) - mirrorCall("staticClass", reify(sym.fullName)) - else if (sym.isStatic && sym.isModule) - mirrorCall("staticModule", reify(sym.fullName)) - else if (isLocatable(sym)) - if (sym.isTypeParameter) - mirrorCall("selectParam", reify(sym.owner), reify(sym.paramPos)) - else { - if (reifyDebug) println("locatable: " + sym + " " + sym.isPackageClass + " " + sym.owner + " " + sym.isTypeParameter) - val rowner = reify(sym.owner) - val rname = reify(sym.name.toString) - if (sym.isType) - mirrorCall("selectType", rowner, rname) - else if (sym.isMethod && sym.owner.isClass && sym.owner.info.decl(sym.name).isOverloaded) { - val index = sym.owner.info.decl(sym.name).alternatives indexOf sym - assert(index >= 0, sym) - mirrorCall("selectOverloadedMethod", rowner, rname, reify(index)) - } else - mirrorCall("selectTerm", rowner, rname) - } - else { - if (sym.isTerm) { - if (reifyDebug) println("Free: " + sym) - val symtpe = lambdaLift.boxIfCaptured(sym, sym.tpe, erasedTypes = false) - def markIfCaptured(arg: Ident): Tree = - if (sym.isCapturedVariable) referenceCapturedVariable(arg) else arg - mirrorCall("newFreeVar", reify(sym.name.toString), reify(symtpe), markIfCaptured(Ident(sym))) - } else { - if (reifyDebug) println("Late local: " + sym) - registerReifiableSymbol(sym) - reifySymRef(sym) - } - } - } - } - - /** - * reify the creation of a symbol - */ - private def reifySymbolDef(sym: Symbol): Tree = { - if (reifyDebug) println("reify sym def " + sym) - - ValDef(NoMods, localName(sym), TypeTree(), - Apply( - Select(reify(sym.owner), "newNestedSymbol"), - List(reify(sym.name), reify(sym.pos), Literal(Constant(sym.flags))) - ) - ) - } - - /** - * Generate code to add type and annotation info to a reified symbol - */ - private def fillInSymbol(sym: Symbol): Tree = { - val rset = Apply(Select(reifySymRef(sym), nme.setTypeSignature), List(reifyType(sym.info))) - if (sym.annotations.isEmpty) rset - else Apply(Select(rset, nme.setAnnotations), List(reify(sym.annotations))) - } - - /** Reify a scope */ - private def reifyScope(scope: Scope): Tree = { - scope foreach registerReifiableSymbol - mirrorCall(nme.newScopeWith, scope.toList map reifySymRef: _*) - } - - /** Reify a list of symbols that need to be created */ - private def reifySymbols(syms: List[Symbol]): Tree = { - syms foreach registerReifiableSymbol - mkList(syms map reifySymRef) - } - - /** Reify a type that defines some symbols */ - private def reifyTypeBinder(value: Product, bound: List[Symbol], underlying: Type): Tree = - mirrorFactoryCall(value, reifySymbols(bound), reify(underlying)) - - /** Reify a type */ - private def reifyType(tpe0: Type): Tree = { - val tpe = tpe0.normalize - - if (tpe.isErroneous) - CannotReifyErroneousType(tpe) - if (definedInLiftedCode(tpe)) - CannotReifyTypeInvolvingBoundType(tpe) - - val tsym = tpe.typeSymbol - if (tsym.isClass && tpe == tsym.typeConstructor && tsym.isStatic) - Select(reifySymRef(tpe.typeSymbol), nme.asTypeConstructor) - else tpe match { - case t @ NoType => - reifyMirrorObject(t) - case t @ NoPrefix => - reifyMirrorObject(t) - case tpe @ ThisType(clazz) if clazz.isModuleClass && clazz.isStatic => - mirrorCall(nme.thisModuleType, reify(clazz.fullName)) - case t @ RefinedType(parents, decls) => - registerReifiableSymbol(tpe.typeSymbol) - mirrorFactoryCall(t, reify(parents), reify(decls), reify(t.typeSymbol)) - case t @ ClassInfoType(parents, decls, clazz) => - registerReifiableSymbol(clazz) - mirrorFactoryCall(t, reify(parents), reify(decls), reify(t.typeSymbol)) - case t @ ExistentialType(tparams, underlying) => - reifyTypeBinder(t, tparams, underlying) - case t @ PolyType(tparams, underlying) => - reifyTypeBinder(t, tparams, underlying) - case t @ MethodType(params, restpe) => - reifyTypeBinder(t, params, restpe) - case t @ AnnotatedType(anns, underlying, selfsym) => - val saved1 = reifySymbols - val saved2 = reifyTypes - - try { - // one more quirk of reifying annotations - // - // when reifying AnnotatedTypes we need to reify all the types and symbols of inner ASTs - // that's because a lot of logic expects post-typer trees to have non-null tpes - // - // Q: reified trees are pre-typer, so there's shouldn't be a problem. - // reflective typechecker will fill in missing symbols and types, right? - // A: actually, no. annotation ASTs live inside AnnotatedTypes, - // and insides of the types is the place where typechecker doesn't look. - reifySymbols = true - reifyTypes = true - if (reifyDebug) println("reify AnnotatedType: " + tpe) - reifyProductUnsafe(tpe) - } finally { - reifySymbols = saved1 - reifyTypes = saved2 - } - case _ => - reifyProductUnsafe(tpe) - } - } - - var reifySymbols = false - var reifyTypes = false - - /** Preprocess a tree before reification */ - private def trimTree(tree: Tree): Tree = { - def trimSyntheticCaseClassMembers(deff: Tree, stats: List[Tree]) = { - var stats1 = stats filterNot (stat => stat.isDef && { - if (stat.symbol.isCaseAccessorMethod && reifyDebug) println("discarding case accessor method: " + stat) - stat.symbol.isCaseAccessorMethod - }) - stats1 = stats1 filterNot (memberDef => memberDef.isDef && { - val isSynthetic = memberDef.symbol.isSynthetic - // @xeno.by: this doesn't work for local classes, e.g. for ones that are top-level to a quasiquote (see comments to companionClass) - // that's why I replace the check with an assumption that all synthetic members are, in fact, generated of case classes -// val isCaseMember = deff.symbol.isCaseClass || deff.symbol.companionClass.isCaseClass - val isCaseMember = true - if (isSynthetic && isCaseMember && reifyDebug) println("discarding case class synthetic def: " + memberDef) - isSynthetic && isCaseMember - }) - stats1 = stats1 map { - case valdef @ ValDef(mods, name, tpt, rhs) if valdef.symbol.isCaseAccessor => - if (reifyDebug) println("resetting visibility of case accessor field: " + valdef) - val Modifiers(flags, privateWithin, annotations) = mods - val flags1 = flags & ~Flags.LOCAL & ~Flags.PRIVATE - val mods1 = Modifiers(flags1, privateWithin, annotations) - ValDef(mods1, name, tpt, rhs).copyAttrs(valdef) - case stat => - stat - } - stats1 - } - - def trimSyntheticCaseClassCompanions(stats: List[Tree]) = - stats diff (stats collect { case moddef: ModuleDef => moddef } filter (moddef => { - val isSynthetic = moddef.symbol.isSynthetic - // @xeno.by: this doesn't work for local classes, e.g. for ones that are top-level to a quasiquote (see comments to companionClass) - // that's why I replace the check with an assumption that all synthetic modules are, in fact, companions of case classes -// val isCaseCompanion = moddef.symbol.companionClass.isCaseClass - val isCaseCompanion = true - // @xeno.by: we also have to do this ugly hack for the very same reason described above - // normally this sort of stuff is performed in reifyTree, which binds related symbols, however, local companions will be out of its reach - if (reifyDebug) println("boundSym: "+ moddef.symbol) - boundSyms += moddef.symbol - if (isSynthetic && isCaseCompanion && reifyDebug) println("discarding synthetic case class companion: " + moddef) - isSynthetic && isCaseCompanion - })) - - tree match { - case tree if tree.isErroneous => - tree - case ta @ TypeApply(hk, ts) => - def isErased(tt: TypeTree) = tt.tpe != null && definedInLiftedCode(tt.tpe) && tt.original == null - val discard = ts collect { case tt: TypeTree => tt } exists isErased - if (reifyDebug && discard) println("discarding TypeApply: " + tree) - if (discard) hk else ta - case classDef @ ClassDef(mods, name, params, impl) => - val Template(parents, self, body) = impl - val body1 = trimSyntheticCaseClassMembers(classDef, body) - var impl1 = Template(parents, self, body1).copyAttrs(impl) - ClassDef(mods, name, params, impl1).copyAttrs(classDef) - case moduledef @ ModuleDef(mods, name, impl) => - val Template(parents, self, body) = impl - val body1 = trimSyntheticCaseClassMembers(moduledef, body) - var impl1 = Template(parents, self, body1).copyAttrs(impl) - ModuleDef(mods, name, impl1).copyAttrs(moduledef) - case template @ Template(parents, self, body) => - val body1 = trimSyntheticCaseClassCompanions(body) - Template(parents, self, body1).copyAttrs(template) - case block @ Block(stats, expr) => - val stats1 = trimSyntheticCaseClassCompanions(stats) - Block(stats1, expr).copyAttrs(block) - case valdef @ ValDef(mods, name, tpt, rhs) if valdef.symbol.isLazy => - if (reifyDebug) println("dropping $lzy in lazy val's name: " + tree) - val name1 = if (name endsWith nme.LAZY_LOCAL) name dropRight nme.LAZY_LOCAL.length else name - ValDef(mods, name1, tpt, rhs).copyAttrs(valdef) - case unapply @ UnApply(fun, args) => - def extractExtractor(tree: Tree): Tree = { - val Apply(fun, args) = tree - args match { - case List(Ident(special)) if special == nme.SELECTOR_DUMMY => - val Select(extractor, flavor) = fun - assert(flavor == nme.unapply || flavor == nme.unapplySeq) - extractor - case _ => - extractExtractor(fun) - } - } - - if (reifyDebug) println("unapplying unapply: " + tree) - val fun1 = extractExtractor(fun) - Apply(fun1, args).copyAttrs(unapply) - case _ => - tree - } - } - - /** Reify a tree */ - private def reifyTree(tree0: Tree): Tree = { - val tree = trimTree(tree0) - - var rtree = tree match { - case tree if tree.isErroneous => - CannotReifyErroneousTree(tree) - case self.EmptyTree => - reifyMirrorObject(EmptyTree) - case self.emptyValDef => - mirrorSelect(nme.emptyValDef) - case This(_) if tree.symbol != NoSymbol && !(boundSyms contains tree.symbol) => - reifyFree(tree) - case Ident(_) if tree.symbol != NoSymbol && !(boundSyms contains tree.symbol) => - if (tree.symbol.isVariable && tree.symbol.owner.isTerm) { - if (reifyDebug) println("captured variable: " + tree.symbol) - captureVariable(tree.symbol) // Note order dependency: captureVariable needs to come before reifyTree here. - mirrorCall("Select", reifyFree(tree), reifyName(nme.elem)) - } else reifyFree(tree) - case tt: TypeTree if (tt.tpe != null) => - reifyTypeTree(tt) - case Literal(constant @ Constant(tpe: Type)) if boundSyms exists (tpe contains _) => - CannotReifyClassOfBoundType(tree, tpe) - case Literal(constant @ Constant(sym: Symbol)) if boundSyms contains sym => - CannotReifyClassOfBoundEnum(tree, constant.tpe) - case tree if tree.isDef => - if (reifyDebug) println("boundSym: %s of type %s".format(tree.symbol, (tree.productIterator.toList collect { case tt: TypeTree => tt } headOption).getOrElse(TypeTree(tree.tpe)))) - boundSyms += tree.symbol - - bindRelatedSymbol(tree.symbol.sourceModule, "sourceModule") - bindRelatedSymbol(tree.symbol.moduleClass, "moduleClass") - bindRelatedSymbol(tree.symbol.companionClass, "companionClass") - bindRelatedSymbol(tree.symbol.companionModule, "companionModule") - Some(tree.symbol) collect { case termSymbol: TermSymbol => bindRelatedSymbol(termSymbol.referenced, "referenced") } - def bindRelatedSymbol(related: Symbol, name: String): Unit = - if (related != null && related != NoSymbol) { - if (reifyDebug) println("boundSym (" + name + "): " + related) - boundSyms += related - } - - val prefix = tree.productPrefix - val elements = (tree.productIterator map { - // annotations exist in two flavors: - // 1) pre-typer ones that populate: a) Modifiers, b) Annotated nodes (irrelevant in this context) - // 2) post-typer ones that dwell inside: a) sym.annotations, b) AnnotatedTypes (irrelevant in this context) - // - // here we process Modifiers that are involved in deftrees - // AnnotatedTypes get reified elsewhere (currently, in ``reifyTypeTree'') - case Modifiers(flags, privateWithin, annotations) => - assert(annotations.isEmpty) // should've been eliminated by the typer - val postTyper = tree.symbol.annotations filter (_.original != EmptyTree) - if (reifyDebug && !postTyper.isEmpty) println("reify symbol annotations for %s: %s".format(tree.symbol, tree.symbol.annotations)) - val preTyper = postTyper map toPreTyperAnnotation - Modifiers(flags, privateWithin, preTyper) - case x => - x - }).toList - reifyProduct(prefix, elements) - case _ => - reifyProduct(tree) - } - - // usually we don't reify symbols/types, because they can be re-inferred during subsequent reflective compilation - // however, reification of AnnotatedTypes is special. see ``reifyType'' to find out why. - if (reifySymbols && tree.hasSymbol) { - if (reifyDebug) println("reifying symbol %s for tree %s".format(tree.symbol, tree)) - rtree = Apply(Select(rtree, nme.setSymbol), List(reifySymRef(tree.symbol))) - } - if (reifyTypes && tree.tpe != null) { - if (reifyDebug) println("reifying type %s for tree %s".format(tree.tpe, tree)) - rtree = Apply(Select(rtree, nme.setType), List(reifyType(tree.tpe))) - } - - rtree - } - - /** Reify pre-typer representation of a type. - * - * NB: This is the trickiest part of reification! - * - * In most cases, we're perfectly fine to reify a Type itself (see ``reifyType''). - * However if the type involves a symbol declared inside the quasiquote (i.e. registered in ``boundSyms''), - * then we cannot reify it, or otherwise subsequent reflective compilation will fail. - * - * Why will it fail? Because reified deftrees (e.g. ClassDef(...)) will generate fresh symbols during that compilation, - * so naively reified symbols will become out of sync, which brings really funny compilation errors and/or crashes, e.g.: - * https://issues.scala-lang.org/browse/SI-5230 - * - * To deal with this unpleasant fact, we need to fall back from types to equivalent trees (after all, parser trees don't contain any types, just trees, so it should be possible). - * Luckily, these original trees get preserved for us in the ``original'' field when Trees get transformed into TypeTrees. - * And if an original of a type tree is empty, we can safely assume that this type is non-essential (e.g. was inferred/generated by the compiler). - * In that case the type can be omitted (e.g. reified as an empty TypeTree), since it will be inferred again later on. - * - * An important property of the original is that it isn't just a pre-typer tree. - * It's actually kind of a post-typer tree with symbols assigned to its Idents (e.g. Ident("List") will contain a symbol that points to immutable.this.List). - * This is very important, since subsequent reflective compilation won't have to resolve these symbols. - * In general case, such resolution cannot be performed, since reification doesn't preserve lexical context, - * which means that reflective compilation won't be aware of, say, imports that were provided when the reifee has been compiled. - * - * This workaround worked surprisingly well and allowed me to fix several important reification bugs, until the abstraction has leaked. - * Suddenly I found out that in certain contexts original trees do not contain symbols, but are just parser trees. - * To the moment I know only one such situation: typedAnnotations does not typecheck the annotation in-place, but rather creates new trees and typechecks them, so the original remains symless. - * This is laboriously worked around in the code below. I hope this will be the only workaround in this department. - */ - private def reifyTypeTree(tt: TypeTree): Tree = { - if (definedInLiftedCode(tt.tpe)) { - if (reifyDebug) println("reifyTypeTree, defined in lifted code: " + tt.tpe) - if (tt.original != null) { - val annotations = tt.tpe filter { _.isInstanceOf[AnnotatedType] } collect { case atp: AnnotatedType => atp.annotations } flatten - val annmap = annotations map { ann => (ann.original, ann) } toMap - - // annotations exist in two flavors: - // 1) pre-typer ones that populate: a) Modifiers (irrelevant in this context), b) Annotated nodes - // 2) post-typer ones that dwell inside: a) sym.annotations (irrelevant in this context), b) AnnotatedTypes - // - // here we process AnnotatedTypes, since only they can be involved in TypeTrees - // Modifiers get reified elsewhere (currently, in the "isDef" case of ``reifyTree'') - // - // the problem with annotations is that their originals don't preserve any symbols at all - // read the comment to this method to find out why it's bad - // that's why we transplant typechecked, i.e. symful, annotations onto original trees - class AnnotationFixup extends self.Transformer { - override def transform(tree: Tree) = tree match { - case Annotated(ann0, args) => - assert(annmap contains ann0) - val ann1 = annmap(ann0) - val ann = toPreTyperAnnotation(ann1) - Annotated(ann, transform(args)) - case _ => - tree - } - } - - if (reifyDebug) println("verdict: essential, reify as original") - val patchedOriginal = new AnnotationFixup().transform(tt.original) - reifyTree(patchedOriginal) - } else { - // type is deemed to be non-essential - // erase it and hope that subsequent reflective compilation will be able to recreate it again - if (reifyDebug) println("verdict: non-essential, discard") - mirrorCall("TypeTree") - } - } else { - var rtt = mirrorCall(nme.TypeTree, reifyType(tt.tpe)) - // @xeno.by: temporarily disabling reification of originals - // subsequent reflective compilation will try to typecheck them - // and this means that the reifier has to do additional efforts to ensure that this will succeed - // additional efforts + no clear benefit = will be implemented later -// if (tt.original != null) { -// val setOriginal = Select(rtt, newTermName("setOriginal")) -// val reifiedOriginal = reify(tt.original) -// rtt = Apply(setOriginal, List(reifiedOriginal)) -// } - rtt - } - } - - /** Reify post-typer representation of an annotation */ - private def reifyAnnotation(ann: AnnotationInfo): Tree = - // @xeno.by: if you reify originals, you get SO when trying to reify AnnotatedTypes, so screw it - after all, it's not that important - mirrorFactoryCall("AnnotationInfo", reifyType(ann.atp), reifyList(ann.args), reify(ann.assocs)) - - /** Reify pre-typer representation of an annotation. - * The trick here is to retain the symbols that have been populated during typechecking of the annotation. - * If we do not do that, subsequent reflective compilation will fail. - */ - private def toPreTyperAnnotation(ann: AnnotationInfo): Tree = { - if (definedInLiftedCode(ann.atp)) { - // todo. deconstruct reifiable tree from ann.original and ann.args+ann.assocs - // - // keep in mind that we can't simply use ann.original, because its args are symless - // which means that any imported symbol (e.g. List) will crash subsequent reflective compilation - // hint: if I had enough time, I'd try to extract reifiable annotation type from ann.original - // and to apply its constructor to ann.args (that are symful, i.e. suitable for reification) - // - // also, if we pursue the route of reifying annotations defined in lifted code - // we should think about how to provide types for all nodes of the return value - // this will be necessary for reifying AnnotatedTypes, since ASTs inside ATs must all have non-null tpes - // an alternative would be downgrading ATs to Annotated nodes, but this needs careful thinking - // for now I just leave this as an implementation restriction - CannotReifyAnnotationInvolvingBoundType(ann) - } else { - val args = if (ann.assocs.isEmpty) { - ann.args - } else { - def toScalaAnnotation(jann: ClassfileAnnotArg): Tree = jann match { - case LiteralAnnotArg(const) => - Literal(const) - case ArrayAnnotArg(arr) => - Apply(Ident(definitions.ArrayModule), arr.toList map toScalaAnnotation) - case NestedAnnotArg(ann) => - toPreTyperAnnotation(ann) - } - - ann.assocs map { case (nme, arg) => AssignOrNamedArg(Ident(nme), toScalaAnnotation(arg)) } - } - - New(ann.atp, args: _*) - } - } - - /** - * Reify a free reference. The result will be either a mirror reference - * to a global value, or else a mirror Literal. - */ - private def reifyFree(tree: Tree): Tree = tree match { - case This(_) if tree.symbol.isClass && !tree.symbol.isModuleClass => - val sym = tree.symbol - if (reifyDebug) println("This for %s, reified as freeVar".format(sym)) - if (reifyDebug) println("Free: " + sym) - val freeVar = mirrorCall("newFreeVar", reify(sym.name.toString), reify(sym.tpe), This(sym)) - mirrorCall(nme.Ident, freeVar) - case This(_) => - if (reifyDebug) println("This for %s, reified as This".format(tree.symbol)) - mirrorCall(nme.This, reifySymRef(tree.symbol)) - case _ => - mirrorCall(nme.Ident, reifySymRef(tree.symbol)) - } - - // todo: consider whether we should also reify positions - private def reifyPosition(pos: Position): Tree = - reifyMirrorObject(NoPosition) - - // !!! we must eliminate these casts. - private def reifyProductUnsafe(x: Any): Tree = - if (x.isInstanceOf[Product]) reifyProduct(x.asInstanceOf[Product]) - else throw new Exception("%s of type %s cannot be cast to Product".format(x, x.getClass)) - private def reifyProduct(x: Product): Tree = - reifyProduct(x.productPrefix, x.productIterator.toList) - private def reifyProduct(prefix: String, elements: List[Any]): Tree = { - // @xeno.by: reflection would be more robust, but, hey, this is a hot path - if (prefix.startsWith("Tuple")) reifyAggregate(prefix, elements: _*) - else mirrorCall(prefix, (elements map reify): _*) - } - - /** - * Reify a case object defined in Mirror - */ - private def reifyMirrorObject(name: String): Tree = mirrorSelect(name) - private def reifyMirrorObject(x: Product): Tree = reifyMirrorObject(x.productPrefix) - - private def isReifiableConstant(value: Any) = value match { - case null => true // seems pretty reifable to me? - case _: String => true - case _ => isAnyVal(value) - } - - /** Reify an arbitary value */ - private def reify(value: Any): Tree = value match { - case tree: Tree => reifyTree(tree) - case sym: Symbol => reifySymRef(sym) - case tpe: Type => reifyType(tpe) - case xs: List[_] => reifyList(xs) - case xs: Array[_] => reifyArray(xs) - case scope: Scope => reifyScope(scope) - case x: Name => reifyName(x) - case x: Position => reifyPosition(x) - case x: Modifiers => reifyModifiers(x) - case x: AnnotationInfo => reifyAnnotation(x) - case _ => - if (isReifiableConstant(value)) Literal(Constant(value)) - else reifyProductUnsafe(value) - } - - /** - * An (unreified) path that refers to definition with given fully qualified name - * @param mkName Creator for last portion of name (either TermName or TypeName) - */ - private def path(fullname: String, mkName: String => Name): Tree = { - val parts = fullname split "\\." - val prefixParts = parts.init - val lastName = mkName(parts.last) - if (prefixParts.isEmpty) Ident(lastName) - else { - val prefixTree = ((Ident(prefixParts.head): Tree) /: prefixParts.tail)(Select(_, _)) - Select(prefixTree, lastName) - } - } - - /** An (unreified) path that refers to term definition with given fully qualified name */ - private def termPath(fullname: String): Tree = path(fullname, newTermName) - - /** An (unreified) path that refers to type definition with given fully qualified name */ - private def typePath(fullname: String): Tree = path(fullname, newTypeName) - - private def mirrorAlias = - ValDef(NoMods, nme.MIRROR_SHORT, SingletonTypeTree(termPath(fullnme.MirrorPackage)), termPath(fullnme.MirrorPackage)) - - /** - * Generate code that generates a symbol table of all symbols registered in `reifiableSyms` - */ - private def reifySymbolTableSetup: List[Tree] = { - val symDefs, fillIns = new mutable.ArrayBuffer[Tree] - var i = 0 - while (i < reifiableSyms.length) { - // fillInSymbol might create new reifiableSyms, that's why this is done iteratively - symDefs += reifySymbolDef(reifiableSyms(i)) - fillIns += fillInSymbol(reifiableSyms(i)) - i += 1 - } - - symDefs.toList ++ fillIns.toList - } - } // end of Reifier - - object Reifier { - def CannotReifyPreTyperTree(tree: Tree) = { - val msg = "pre-typer trees are not supported, consider typechecking the tree before passing it to the reifier" - throw new ReifierError(tree.pos, msg) - } - - def CannotReifyErroneousTree(tree: Tree) = { - val msg = "erroneous trees are not supported, make sure that your tree typechecks successfully before passing it to the reifier" - throw new ReifierError(tree.pos, msg) - } - - def CannotReifyErroneousType(tpe: Type) = { - val msg = "erroneous types are not supported, make sure that your tree typechecks successfully before passing it to the reifier" - throw new ReifierError(NoPosition, msg) - } - - def CannotReifyClassOfBoundType(tree: Tree, tpe: Type) = { - val msg = "implementation restriction: cannot reify classOf[%s] which refers to a type declared inside the block being reified".format(tpe) - throw new ReifierError(tree.pos, msg) - } - - def CannotReifyClassOfBoundEnum(tree: Tree, tpe: Type) = { - val msg = "implementation restriction: cannot reify classOf[%s] which refers to an enum declared inside the block being reified".format(tpe) - throw new ReifierError(tree.pos, msg) - } - - def CannotReifyTypeInvolvingBoundType(tpe: Type) = { - val msg = "implementation restriction: cannot reify type %s which involves a symbol declared inside the block being reified".format(tpe) - throw new ReifierError(NoPosition, msg) - } - - def CannotReifyAnnotationInvolvingBoundType(ann: AnnotationInfo) = { - val msg = "implementation restriction: cannot reify annotation @%s which involves a symbol declared inside the block being reified".format(ann) - throw new ReifierError(ann.original.pos, msg) - } - } // end of Reifier - - // begin reify - import Reifier._ - if (tree.tpe != null) { - val saved = printTypings - try { - val reifyDebug = settings.Yreifydebug.value - val debugTrace = util.trace when reifyDebug - debugTrace("transforming = ")(if (settings.Xshowtrees.value) "\n" + nodePrinters.nodeToString(tree).trim else tree.toString) - debugTrace("transformed = ") { - val reifier = new Reifier() - val untyped = reifier.reifyTopLevel(tree) - - val reifyCopypaste = settings.Yreifycopypaste.value - if (reifyCopypaste) { - if (reifyDebug) println("=======================") - println(reifiedNodeToString(untyped)) - if (reifyDebug) println("=======================") - } - - untyped - } - } finally { - printTypings = saved - } - } else { - CannotReifyPreTyperTree(tree) - } - } - - /** A throwable signalling a reification error */ - class ReifierError(var pos: Position, val msg: String) extends Throwable(msg) { - def this(msg: String) = this(NoPosition, msg) - } -} |