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/* NSC -- new Scala compiler
* Copyright 2005-2009 LAMP/EPFL
* @author Martin Odersky
*/
// $Id$
package scala.tools.nsc.symtab
trait Scopes {
self: SymbolTable =>
class ScopeEntry(val sym: Symbol, val owner: Scope) {
/** the next entry in the hash bucket
*/
var tail: ScopeEntry = _
/** the next entry in this scope
*/
var next: ScopeEntry = null
override def hashCode(): Int = sym.name.start
override def toString(): String = sym.toString()
}
/**
* @param sym ...
* @param owner ...
* @return ...
*/
def newScopeEntry(sym: Symbol, owner: Scope): ScopeEntry = {
val e = new ScopeEntry(sym, owner)
e.next = owner.elems
owner.elems = e
e
}
object NoScopeEntry extends ScopeEntry(NoSymbol, null)
/**
* @param initElems ...
* @return ...
*/
def newScope(initElems: ScopeEntry): Scope = new NormalScope(initElems)
final def newScope: Scope = newScope(null: ScopeEntry)
trait PackageScopeDependMap {
def createDepend(from : Symbol, name : Name) : Unit
}
def newPackageScope(depends0 : PackageScopeDependMap) : PackageScope = {
object MyPackageScope extends NormalScope(null : ScopeEntry) with PackageScope {
val depends = depends0
}
MyPackageScope
}
def newTempScope = newScope(null : ScopeEntry)
class ScopeKind(name : String) { override def toString = name }
def allocateScopeKind(name : String) = new ScopeKind(name)
lazy val Constructor0ScopeKind : ScopeKind = allocateScopeKind("constructors0")
lazy val Constructor1ScopeKind : ScopeKind = allocateScopeKind("constructors1")
lazy val InnerScopeKind : ScopeKind = allocateScopeKind("inner")
lazy val FinishWithScopeKind : ScopeKind = allocateScopeKind("finishWith")
lazy val TypeSigScopeKind : ScopeKind = allocateScopeKind("typeSig")
lazy val PolyTypeCompleterScopeKind : ScopeKind = allocateScopeKind("polyType")
lazy val CompoundTreeScopeKind : ScopeKind = allocateScopeKind("compoundTree")
lazy val FreshArgScopeKind : ScopeKind = allocateScopeKind("freshArgs")
lazy val LabelScopeKind : ScopeKind = allocateScopeKind("label")
lazy val TypedCasesScopeKind : ScopeKind = allocateScopeKind("typedCases")
lazy val TypedDefScopeKind : ScopeKind = allocateScopeKind("typedDef")
//lazy val ParentTypesScopeKind : ScopeKind = allocateScopeKind("parentType")
lazy val TypedScopeKind : ScopeKind = allocateScopeKind("typed")
// have to sometimes use constructor depth unfortunately.
case class ParentTypesScopeKind(clazz : Symbol) extends ScopeKind("parentType") { override def toString = super.toString + "-" + clazz }
case class BlockScopeKind(depth : Int) extends ScopeKind("block") { override def toString = super.toString + "-" + depth }
def newClassScope(clazz : Symbol) = newScope // for use in ClassInfoType creation
def scopeFor( tree : Tree, kind : ScopeKind) : Scope = newScope
def scopeFor(old : Scope, tree : Tree, kind : ScopeKind) : Scope = newScope(old)
final def newScope(base: Scope) : Scope = newScope(base.elems)
final def newScope(decls: List[Symbol]) : Scope = {
val ret = newScope
decls.foreach(d => ret.enter(d))
ret
}
def newThrowAwayScope(decls : List[Symbol]) : Scope = newScope(decls)
// for symbols that don't exist in scopes!
def recycle(sym : Symbol) : Symbol = sym
def newLocalDummy(clazz : Symbol, pos : util.Position) = clazz.newLocalDummy(pos)
private class NormalScope(initElems: ScopeEntry) extends Scope(initElems)
trait PackageScope extends Scope {
val depends : PackageScopeDependMap
override def lookupEntryWithContext(name : Name)(from : Symbol) = {
if (from != NoSymbol && depends != null) {
depends.createDepend(from,name)
}
super.lookupEntryWithContext(name)(from)
}
override def lookupWithContext(name : Name)(from : Symbol) = {
if (from != NoSymbol && depends != null) {
depends.createDepend(from,name)
}
super.lookupWithContext(name)(from)
}
}
abstract class Scope(initElems: ScopeEntry) {
var elems: ScopeEntry = initElems
/** The number of times this scope is neted in another
*/
private var nestinglevel = 0
/** the hash table
*/
private var hashtable: Array[ScopeEntry] = null
/** a cache for all elements, to be used by symbol iterator.
*/
private var elemsCache: List[Symbol] = null
/** size and mask of hash tables
* todo: make hashtables grow?
*/
private val HASHSIZE = 0x80
private val HASHMASK = 0x7f
/** the threshold number of entries from which a hashtable is constructed.
*/
private val MIN_HASH = 8
if (size >= MIN_HASH) createHash()
def this() = this(null: ScopeEntry)
def this(base: Scope) = {
this(base.elems)
/*
if (base.hashtable ne null) {
this.hashtable = new Array[ScopeEntry](HASHSIZE)
System.arraycopy(base.hashtable, 0, this.hashtable, 0, HASHSIZE)
}
*/
nestinglevel = base.nestinglevel + 1
}
def this(decls: List[Symbol]) = {
this()
decls.foreach(sym => enter(sym))
}
/** Returns a new scope with the same content as this one. */
def cloneScope: Scope = {
val clone = newScope
this.toList.foreach(sym => clone.enter(sym))
clone
}
/* clear the contents of this scope */
def clear = {
elems = null
elemsCache = null
hashtable = null
}
/** is the scope empty? */
def isEmpty: Boolean = elems eq null
/** the number of entries in this scope */
def size: Int = {
var s = 0
var e = elems
while (e ne null) {
s += 1
e = e.next
}
s
}
/** enter a scope entry
*
* @param e ...
*/
def enter(e: ScopeEntry) {
elemsCache = null
if (hashtable ne null) {
val i = e.sym.name.start & HASHMASK
elems.tail = hashtable(i)
hashtable(i) = elems
} else if (size >= MIN_HASH) {
createHash()
}
}
/** enter a symbol
*
* @param sym ...
*/
def enter(sym: Symbol) : Symbol = { enter(newScopeEntry(sym, this)); sym }
/** enter a symbol, asserting that no symbol with same name exists in scope
*
* @param sym ...
*/
def enterUnique(sym: Symbol) {
assert(lookup(sym.name) == NoSymbol)
enter(sym)
}
private def createHash() {
hashtable = new Array[ScopeEntry](HASHSIZE)
enterInHash(elems)
}
private def enterInHash(e: ScopeEntry) {
if (e ne null) {
enterInHash(e.next)
val i = e.sym.name.start & HASHMASK
e.tail = hashtable(i)
hashtable(i) = e
}
}
def rehash(sym: Symbol, newname: Name) {
if (hashtable ne null) {
val index = sym.name.start & HASHMASK
var e1 = hashtable(index)
var e: ScopeEntry = null
if (e1 != null) {
if (e1.sym == sym) {
hashtable(index) = e1.tail
e = e1
} else {
while (e1.tail != null && e1.tail.sym != sym) e1 = e1.tail
if (e1.tail != null) {
e = e1.tail
e1.tail = e.tail
}
}
}
if (e != null) {
val newindex = newname.start & HASHMASK
e.tail = hashtable(newindex)
hashtable(newindex) = e
}
}
}
/** remove entry
*
* @param e ...
*/
def unlink(e: ScopeEntry) {
if (elems == e) {
elems = e.next
} else {
var e1 = elems
while (e1.next != e) e1 = e1.next
e1.next = e.next
}
if (hashtable ne null) {
val index = e.sym.name.start & HASHMASK
var e1 = hashtable(index)
if (e1 == e) {
hashtable(index) = e.tail
} else {
while (e1.tail != e) e1 = e1.tail;
e1.tail = e.tail
}
}
elemsCache = null
}
/** remove symbol */
def unlink(sym: Symbol) {
var e = lookupEntry(sym.name)
while (e ne null) {
if (e.sym == sym) unlink(e);
e = lookupNextEntry(e)
}
}
/** lookup a symbol
*
* @param name ...
* @return ...
*/
def lookup(name: Name): Symbol = {
val e = lookupEntry(name)
if (e eq null) NoSymbol else e.sym
}
/** Can lookup symbols and trace who the client is.
*/
def lookupEntryWithContext(name : Name)(from : Symbol) : ScopeEntry = lookupEntry(name)
def lookupWithContext(name : Name)(from : Symbol) : Symbol = lookup(name)
/** lookup a symbol entry matching given name.
*
* @param name ...
* @return ...
*/
def lookupEntry(name: Name): ScopeEntry = {
var e: ScopeEntry = null
if (hashtable ne null) {
e = hashtable(name.start & HASHMASK)
while ((e ne null) && e.sym.name != name) {
e = e.tail
}
} else {
e = elems
while ((e ne null) && e.sym.name != name) {
e = e.next
}
}
e
}
/** lookup next entry with same name as this one */
def lookupNextEntry(entry: ScopeEntry): ScopeEntry = {
var e = entry
if (hashtable ne null) //debug
do { e = e.tail } while ((e ne null) && e.sym.name != entry.sym.name)
else
do { e = e.next } while ((e ne null) && e.sym.name != entry.sym.name);
e
}
/** Return all symbols as a list in the order they were entered in this scope.
*/
def toList: List[Symbol] = {
if (elemsCache eq null) {
elemsCache = Nil
var e = elems
while ((e ne null) && e.owner == this) {
elemsCache = e.sym :: elemsCache
e = e.next
}
}
elemsCache
}
/** Return all symbols as an interator in the order they were entered in this scope.
*/
def iterator: Iterator[Symbol] = toList.iterator
@deprecated def elements = iterator
def filter(p: Symbol => Boolean): Scope =
if (!(toList forall p)) newScope(toList filter p) else this
def mkString(start: String, sep: String, end: String) =
toList.map(_.defString).mkString(start, sep, end)
override def toString(): String = mkString("{\n ", ";\n ", "\n}")
/** Return the nesting level of this scope, i.e. the number of times this scope
* was nested in another */
def nestingLevel = nestinglevel
def invalidate(name : Name) = {}
}
/** The empty scope (immutable).
*/
object EmptyScope extends Scope {
override def enter(e: ScopeEntry) {
throw new Error("EmptyScope.enter")
}
}
/** The error scope.
*/
class ErrorScope(owner: Symbol) extends Scope(null: ScopeEntry) {
override def lookupEntry(name: Name): ScopeEntry = {
val e = super.lookupEntry(name)
if (e != NoScopeEntry) e
else {
enter(if (name.isTermName) owner.newErrorValue(name)
else owner.newErrorClass(name))
super.lookupEntry(name)
}
}
}
}
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