scala.reflect.reify.utils.SymbolTables.scala Maven / Gradle / Ivy
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Compiler for the SubScript extension of the Scala Programming Language
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package scala.reflect.reify
package utils
import scala.collection._
import scala.compat.Platform.EOL
trait SymbolTables {
self: Utils =>
import global._
class SymbolTable private[SymbolTable] (
private[SymbolTable] val symtab: immutable.ListMap[Symbol, Tree] = immutable.ListMap[Symbol, Tree](),
private[SymbolTable] val aliases: List[(Symbol, TermName)] = List[(Symbol, TermName)](),
private[SymbolTable] val original: Option[List[Tree]] = None) {
def syms: List[Symbol] = symtab.keys.toList
def symDef(sym: Symbol): Tree =
symtab.getOrElse(sym, EmptyTree)
def symName(sym: Symbol): TermName =
symtab.get(sym) match {
case Some(FreeDef(_, name, _, _, _)) => name
case Some(SymDef(_, name, _, _)) => name
case None => nme.EMPTY
}
def symAliases(sym: Symbol): List[TermName] =
symName(sym) match {
case name if name.isEmpty => Nil
case _ => (aliases.distinct groupBy (_._1) mapValues (_ map (_._2)))(sym)
}
def symBinding(sym: Symbol): Tree =
symtab.get(sym) match {
case Some(FreeDef(_, _, binding, _, _)) => binding
case Some(SymDef(_, _, _, _)) => throw new UnsupportedOperationException(s"${symtab(sym)} is a symdef, hence it doesn't have a binding")
case None => EmptyTree
}
def symRef(sym: Symbol): Tree =
symtab.get(sym) match {
case Some(FreeDef(_, name, binding, _, _)) => Ident(name) updateAttachment binding
case Some(SymDef(_, name, _, _)) => Ident(name) updateAttachment ReifyBindingAttachment(Ident(sym))
case None => EmptyTree
}
def +(sym: Symbol, name: TermName, reification: Tree): SymbolTable = add(sym, name, reification)
def +(symDef: Tree): SymbolTable = add(symDef)
def ++(symDefs: TraversableOnce[Tree]): SymbolTable = (this /: symDefs)((symtab, symDef) => symtab.add(symDef))
def ++(symtab: SymbolTable): SymbolTable = { val updated = this ++ symtab.symtab.values; new SymbolTable(updated.symtab, updated.aliases ++ symtab.aliases) }
def -(sym: Symbol): SymbolTable = remove(sym)
def -(name: TermName): SymbolTable = remove(name)
def -(symDef: Tree): SymbolTable = remove(reifyBinding(symDef).symbol)
def --(syms: GenTraversableOnce[Symbol]): SymbolTable = (this /: syms)((symtab, sym) => symtab.remove(sym))
def --(names: Iterable[TermName]): SymbolTable = (this /: names)((symtab, name) => symtab.remove(name))
def --(symDefs: TraversableOnce[Tree]): SymbolTable = this -- (symDefs map (reifyBinding(_)))
def --(symtab: SymbolTable): SymbolTable = { val updated = this -- symtab.symtab.values; new SymbolTable(updated.symtab, updated.aliases diff symtab.aliases) }
def filterSyms(p: Symbol => Boolean): SymbolTable = this -- (syms filterNot p)
def filterAliases(p: (Symbol, TermName) => Boolean): SymbolTable = this -- (aliases filterNot (tuple => p(tuple._1, tuple._2)) map (_._2))
private def add(symDef: Tree): SymbolTable = {
val sym = reifyBinding(symDef).symbol
assert(sym != NoSymbol, showRaw(symDef))
val name = symDef match {
case FreeDef(_, name, _, _, _) => name
case SymDef(_, name, _, _) => name
}
val newSymtab = if (!(symtab contains sym)) symtab + (sym -> symDef) else symtab
val newAliases = aliases :+ (sym -> name)
new SymbolTable(newSymtab, newAliases)
}
private def add(sym: Symbol, name0: TermName, reification: Tree): SymbolTable = {
def freshName(name0: TermName): TermName = {
var name = name0.toString
name = name.replace(".type", "$type")
name = name.replace(" ", "$")
val fresh = typer.context.unit.fresh
newTermName(fresh.newName(name))
}
val bindingAttachment = reification.attachments.get[ReifyBindingAttachment].get
add(ValDef(NoMods, freshName(name0), TypeTree(), reification) updateAttachment bindingAttachment)
}
private def remove(sym: Symbol): SymbolTable = {
val newSymtab = symtab - sym
val newAliases = aliases filter (_._1 != sym)
new SymbolTable(newSymtab, newAliases)
}
private def remove(name: TermName): SymbolTable = {
var newSymtab = symtab
val newAliases = aliases filter (_._2 != name)
newSymtab = newSymtab filter { case ((sym, _)) => newAliases exists (_._1 == sym) }
newSymtab = newSymtab map { case ((sym, tree)) =>
val ValDef(mods, primaryName, tpt, rhs) = tree
val tree1 =
if (!(newAliases contains ((sym, primaryName)))) {
val primaryName1 = newAliases.find(_._1 == sym).get._2
ValDef(mods, primaryName1, tpt, rhs).copyAttrs(tree)
} else tree
(sym, tree1)
}
new SymbolTable(newSymtab, newAliases)
}
private val cache = mutable.Map[SymbolTable, List[Tree]]()
def encode: List[Tree] = cache.getOrElseUpdate(this, SymbolTable.encode(this)) map (_.duplicate)
override def toString = {
val symtabString = symtab.keys.map(symName(_)).mkString(", ")
val trueAliases = aliases.distinct.filter(entry => symName(entry._1) != entry._2)
val aliasesString = trueAliases.map(entry => s"${symName(entry._1)} -> ${entry._2}").mkString(", ")
s"""symtab = [$symtabString], aliases = [$aliasesString]${if (original.isDefined) ", has original" else ""}"""
}
def debugString: String = {
val buf = new StringBuilder
buf.append("symbol table = " + (if (syms.length == 0) "" else "")).append(EOL)
syms foreach (sym => buf.append(symDef(sym)).append(EOL))
buf.delete(buf.length - EOL.length, buf.length)
buf.toString
}
}
object SymbolTable {
def apply(): SymbolTable =
new SymbolTable()
def apply(encoded: List[Tree]): SymbolTable = {
var result = new SymbolTable(original = Some(encoded))
encoded foreach (entry => (entry.attachments.get[ReifyBindingAttachment], entry.attachments.get[ReifyAliasAttachment]) match {
case (Some(ReifyBindingAttachment(_)), _) => result += entry
case (_, Some(ReifyAliasAttachment(sym, alias))) => result = new SymbolTable(result.symtab, result.aliases :+ ((sym, alias)))
case _ => // do nothing, this is boilerplate that can easily be recreated by subsequent `result.encode`
})
result
}
private[SymbolTable] def encode(symtab0: SymbolTable): List[Tree] = {
if (symtab0.original.isDefined) return symtab0.original.get.map(_.duplicate)
else assert(hasReifier, "encoding a symbol table requires a reifier")
// during `encode` we might need to do some reifications
// these reifications might lead to changes in `reifier.symtab`
// reifier is mutable, symtab is immutable. this is a tough friendship
val backup = reifier.state.backup
reifier.state.symtab = symtab0.asInstanceOf[reifier.SymbolTable]
def currtab = reifier.symtab.asInstanceOf[SymbolTable]
try {
val cumulativeSymtab = mutable.ArrayBuffer[Tree](symtab0.symtab.values.toList: _*)
val cumulativeAliases = mutable.ArrayBuffer[(Symbol, TermName)](symtab0.aliases: _*)
def fillInSymbol(sym: Symbol): Tree = {
if (reifyDebug) println("Filling in: %s (%s)".format(sym, sym.accurateKindString))
val isFreeTerm = FreeTermDef.unapply(currtab.symDef(sym)).isDefined
// SI-6204 don't reify signatures for incomplete symbols, because this might lead to cyclic reference errors
val signature =
if (sym.isInitialized) {
if (sym.isCapturedVariable) capturedVariableType(sym)
else if (isFreeTerm) sym.tpe
else sym.info
} else NoType
val rset = reifier.mirrorBuildCall(nme.setInfo, currtab.symRef(sym), reifier.reify(signature))
// `Symbol.annotations` doesn't initialize the symbol, so we don't need to do anything special here
// also since we call `sym.info` a few lines above, by now the symbol will be initialized (if possible)
// so the annotations will be filled in and will be waiting to be reified (unless symbol initialization is prohibited as described above)
if (sym.annotations.isEmpty) rset
else reifier.mirrorBuildCall(nme.setAnnotations, rset, reifier.mkList(sym.annotations map reifier.reifyAnnotationInfo))
}
// `fillInSymbol` might add symbols to `symtab`, that's why this is done iteratively
var progress = 0
while (progress < cumulativeSymtab.length) {
val sym = reifyBinding(cumulativeSymtab(progress)).symbol
if (sym != NoSymbol) {
val symtabProgress = currtab.symtab.size
val aliasesProgress = currtab.aliases.length
val fillIn = fillInSymbol(sym)
cumulativeSymtab ++= currtab.symtab.values drop symtabProgress
cumulativeAliases ++= currtab.aliases drop aliasesProgress
cumulativeSymtab += fillIn
}
progress += 1
}
val withAliases = cumulativeSymtab flatMap (entry => {
val result = mutable.ListBuffer[Tree]()
result += entry
val sym = reifyBinding(entry).symbol
if (sym != NoSymbol)
result ++= cumulativeAliases.distinct filter (alias => alias._1 == sym && alias._2 != currtab.symName(sym)) map (alias => {
val canonicalName = currtab.symName(sym)
val aliasName = alias._2
ValDef(NoMods, aliasName, TypeTree(), Ident(canonicalName)) updateAttachment ReifyAliasAttachment(sym, aliasName)
})
result.toList
})
withAliases.toList
} finally {
reifier.state.restore(backup)
}
}
}
}