package dotty.tools.dotc
package core
import Periods._, Contexts._, Symbols._, Referenceds._, Names._
import Types._, Flags._, Decorators._, Transformers._
import Scopes.Scope
import collection.mutable
import collection.immutable.BitSet
object Denotations {
abstract class Denotation extends SymRefd {
def symbol: Symbol = ???
def owner: Symbol = ???
def name: Name = ???
def flags: FlagSet = ???
def setFlag(flag: FlagSet): Unit = ???
def tpe: Type = ???
def info: Type = ???
/* Validity and instance handling:
*
* Symbols have an interval of validity, defined
* by their `valid` fields.
*
* There may be several symbols with different validity
* representing the same underlying symbol at different phases.
* These are called a "flock". Flock members are generated by
* @see SymRef.trackSym. Flock members are connected in a ring
* with their `nextInFlock` fields.
*
* There are the following invariants converning flock members
*
* 1) validity intervals must be non-overlapping
* 2) the union of all validity intervals must be a contiguous
* interval starting in FirstPhaseId.
*/
/** is this symbol a class? */
def isClass: Boolean = false
/** is this symbol a method? */
def isMethod: Boolean = false
/** is this symbol the result of an erroneous definition? */
def isError: Boolean = false
def withType(tp: Type): Denotation = ???
override protected def copy(s: Symbol, i: Type): SymRefd = new UniqueSymRefd(s, i, validFor)
}
object NameFilter {
final val WordSizeLog = 6
final val DefinedNamesWords = 16
final val DefinedNamesSize = DefinedNamesWords << WordSizeLog
final val DefinedNamesMask = DefinedNamesSize - 1
type FingerPrint = Array[Long]
def includeName(bits: FingerPrint, name: Name): Unit = {
val hash = name.start & DefinedNamesMask
bits(hash >> 6) |= (1 << hash)
}
def includeFingerPrint(bits1: FingerPrint, bits2: FingerPrint): Unit =
for (i <- 0 until DefinedNamesWords) bits1(i) |= bits2(i)
def containsName(bits: FingerPrint, name: Name): Boolean = {
val hash = name.start & DefinedNamesMask
(bits(hash >> 6) & (1 << hash)) != 0
}
def newNameFilter: FingerPrint = new Array[Long](DefinedNamesWords)
}
class ClassDenotation(val parents: List[Type], val decls: Scope, val clazz: ClassSymbol) extends Denotation {
import NameFilter._
import util.LRU8Cache
def typeParams: List[TypeSymbol] = ???
private var memberCacheVar: LRU8Cache[Name, ReferencedSet] = null
private def memberCache: LRU8Cache[Name, ReferencedSet] = {
if (memberCacheVar == null) memberCacheVar = new LRU8Cache
memberCacheVar
}
private var thisTypeCache: ThisType = null
def thisType(implicit ctx: Context): Type = {
if (thisTypeCache == null)
thisTypeCache = ThisType(clazz)
thisTypeCache
}
private var typeConstructorCache: Type = null
def typeConstructor(implicit ctx: Context): Type = {
if (typeConstructorCache == null)
typeConstructorCache = NamedType(thisType, clazz.name)
typeConstructorCache
}
private var typeTemplateCache: Type = null
def typeTemplate(implicit ctx: Context): Type = {
if (typeTemplateCache == null)
AppliedType.make(typeConstructor, typeParams map (_.typeConstructor))
typeTemplateCache
}
private var baseClassesVar: List[ClassSymbol] = null
private var superClassBitsVar: BitSet = null
private def computeSuperClassBits(implicit ctx: Context): Unit = {
val seen = new mutable.BitSet
val locked = new mutable.BitSet
def addBaseClasses(bcs: List[ClassSymbol], to: List[ClassSymbol])
: List[ClassSymbol] = bcs match {
case bc :: bcs1 =>
val id = bc.superId
if (seen contains id) to
else if (locked contains id) throw new CyclicReference(clazz)
else {
locked += id
val bcs1added = addBaseClasses(bcs1, to)
seen += id
if (bcs1added eq bcs1) bcs else bc :: bcs1added
}
case _ =>
to
}
def addParentBaseClasses(ps: List[Type], to: List[ClassSymbol]): List[ClassSymbol] = ps match {
case p :: ps1 =>
addBaseClasses(p.baseClasses, addParentBaseClasses(ps1, to))
case _ =>
to
}
baseClassesVar = clazz :: addParentBaseClasses(parents, Nil)
superClassBitsVar = ctx.root.uniqueBits.findEntryOrUpdate(seen.toImmutable)
}
def superClassBits(implicit ctx: Context): BitSet = {
if (superClassBitsVar == null) computeSuperClassBits
superClassBitsVar
}
def baseClasses(implicit ctx: Context): List[ClassSymbol] = {
if (baseClassesVar == null) computeSuperClassBits
baseClassesVar
}
/** Is this class a subclass of `clazz`? */
final def isSubClass(clazz: ClassSymbol)(implicit ctx: Context): Boolean = {
superClassBits contains clazz.superId
}
private var definedFingerPrintCache: FingerPrint = null
private def computeDefinedFingerPrint(implicit ctx: Context): FingerPrint = {
var bits = newNameFilter
var e = decls.lastEntry
while (e != null) {
includeName(bits, clazz.name)
e = e.prev
}
var ps = parents
while (ps.nonEmpty) {
val parent = ps.head.typeSymbol
parent.deref match {
case classd: ClassDenotation =>
includeFingerPrint(bits, classd.definedFingerPrint)
parent.deref setFlag Frozen
case _ =>
}
ps = ps.tail
}
definedFingerPrintCache = bits
bits
}
/** Enter a symbol in current scope.
* Note: We require that this does not happen after the first time
* someone does a findMember on a subclass.
*/
def enter(sym: Symbol)(implicit ctx: Context) = {
require((clazz.flags & Frozen) == Flags.Empty)
decls enter sym
if (definedFingerPrintCache != null)
includeName(definedFingerPrintCache, sym.name)
if (memberCacheVar != null)
memberCache invalidate sym.name
}
/** Delete symbol from current scope.
* Note: We require that this does not happen after the first time
* someone does a findMember on a subclass.
*/
def delete(sym: Symbol)(implicit ctx: Context) = {
require((clazz.flags & Frozen) == Flags.Empty)
decls unlink sym
if (definedFingerPrintCache != null)
computeDefinedFingerPrint
if (memberCacheVar != null)
memberCache invalidate sym.name
}
def definedFingerPrint(implicit ctx: Context): FingerPrint = {
val fp = definedFingerPrintCache
if (fp != null) fp else computeDefinedFingerPrint
}
final def memberRefsNamed(name: Name)(implicit ctx: Context): ReferencedSet = {
var refs: ReferencedSet = memberCache lookup name
if (refs == null) {
if (containsName(definedFingerPrint, name)) {
val ownRefs = decls.refsNamed(name)
refs = ownRefs
var ps = parents
while (ps.nonEmpty) {
val parentSym = ps.head.typeSymbol
parentSym.deref match {
case parentd: ClassDenotation =>
refs = refs union
parentd.memberRefsNamed(name)
.filterExcluded(Flags.Private)
.asSeenFrom(thisType, parentSym)
.filterDisjoint(ownRefs)
case _ =>
}
}
} else {
refs = NoRefd
}
memberCache enter (name, refs)
}
refs
}
private var baseTypeCache: java.util.HashMap[CachedType, Type] = null
private var baseTypeValid: RunId = NoRunId
final def baseTypeOf(tp: Type)(implicit ctx: Context): Type = {
def computeBaseTypeOf(tp: Type): Type = tp match {
case AppliedType(tycon, args) =>
baseTypeOf(tycon).subst(tycon.typeParams, args)
case tp: TypeProxy =>
baseTypeOf(tp.underlying)
case AndType(tp1, tp2) =>
baseTypeOf(tp1) & baseTypeOf(tp2)
case OrType(tp1, tp2) =>
baseTypeOf(tp1) | baseTypeOf(tp2)
case tp @ ClassInfo(pre, classd) =>
def reduce(bt: Type, ps: List[Type]): Type = ps match {
case p :: ps1 => reduce(bt & baseTypeOf(p), ps1)
case _ => bt
}
if (classd.clazz == clazz) tp.typeTemplate
else reduce(NoType, classd.parents).substThis(classd.clazz, tp.prefix)
}
if (clazz.isStaticMono) clazz.typeConstructor
else tp match {
case tp: CachedType =>
if (baseTypeValid != ctx.runId) {
baseTypeCache = new java.util.HashMap[CachedType, Type]
baseTypeValid = ctx.runId
}
var basetp = baseTypeCache get tp
if (basetp == null) {
baseTypeCache.put(tp, NoType)
basetp = computeBaseTypeOf(tp)
baseTypeCache.put(tp, basetp)
} else if (basetp == NoType) {
throw new CyclicReference(clazz)
}
basetp
case _ =>
computeBaseTypeOf(tp)
}
}
private var memberNamesCache: Map[NameFilter, Set[Name]] = Map()
def memberNames(keepOnly: NameFilter)(implicit ctx: Context): Set[Name] =
memberNamesCache get keepOnly match {
case Some(names) =>
names
case _ =>
val inheritedNames = (parents flatMap (_.memberNames(thisType, keepOnly))).toSet
val ownNames = decls.iterator map (_.name)
val candidates = inheritedNames ++ ownNames
val names = candidates filter (keepOnly(thisType, _))
memberNamesCache += (keepOnly -> names)
names
}
}
object NoDenotation extends Denotation {
override def owner: Symbol = throw new AssertionError("NoDenotation.owner")
override def name: Name = BootNameTable.newTermName("<none>")
override def flags = Flags.Empty
override def tpe: Type = NoType
override def info: Type = NoType
}
}
