package dotty.tools
package dotc
package core
import Periods._, Contexts._, Symbols._, Denotations._, Names._, NameOps._, Annotations._
import Types._, Flags._, Decorators._, DenotTransformers._, StdNames._, Scopes._
import NameOps._
import Scopes.Scope
import collection.mutable
import collection.immutable.BitSet
import scala.reflect.io.AbstractFile
import Decorators.SymbolIteratorDecorator
import ast._
import annotation.tailrec
import CheckRealizable._
import util.SimpleMap
import util.Stats
import config.Config
import config.Printers._
trait SymDenotations { this: Context =>
import SymDenotations._
/** Factory method for SymDenotion creation. All creations
* should be done via this method.
*/
def SymDenotation(
symbol: Symbol,
owner: Symbol,
name: Name,
initFlags: FlagSet,
initInfo: Type,
initPrivateWithin: Symbol = NoSymbol)(implicit ctx: Context): SymDenotation = {
val result =
if (symbol.isClass)
if (initFlags is Package) new PackageClassDenotation(symbol, owner, name, initFlags, initInfo, initPrivateWithin, ctx.runId)
else new ClassDenotation(symbol, owner, name, initFlags, initInfo, initPrivateWithin, ctx.runId)
else new SymDenotation(symbol, owner, name, initFlags, initInfo, initPrivateWithin)
result.validFor = stablePeriod
result
}
def stillValid(denot: SymDenotation): Boolean =
if (denot.is(ValidForever) || denot.isRefinementClass) true
else {
val initial = denot.initial
val firstPhaseId = initial.validFor.firstPhaseId.max(ctx.typerPhase.id)
if ((initial ne denot) || ctx.phaseId != firstPhaseId)
ctx.withPhase(firstPhaseId).stillValidInOwner(initial.asSymDenotation)
else
stillValidInOwner(denot)
}
private[SymDenotations] def stillValidInOwner(denot: SymDenotation): Boolean = try {
val owner = denot.owner.denot
stillValid(owner) && (
!owner.isClass
|| owner.isRefinementClass
|| (owner.unforcedDecls.lookupAll(denot.name) contains denot.symbol)
|| denot.isSelfSym)
} catch {
case ex: StaleSymbol => false
}
/** Explain why symbol is invalid; used for debugging only */
def traceInvalid(denot: Denotation): Boolean = {
def show(d: Denotation) = s"$d#${d.symbol.id}"
def explain(msg: String) = {
println(s"${show(denot)} is invalid at ${this.period} because $msg")
false
}
denot match {
case denot: SymDenotation =>
def explainSym(msg: String) = explain(s"$msg\n defined = ${denot.definedPeriodsString}")
if (denot.is(ValidForever) || denot.isRefinementClass) true
else {
implicit val ctx: Context = this
val initial = denot.initial
if ((initial ne denot) || ctx.phaseId != initial.validFor.firstPhaseId) {
ctx.withPhase(initial.validFor.firstPhaseId).traceInvalid(initial.asSymDenotation)
} else try {
val owner = denot.owner.denot
if (!traceInvalid(owner)) explainSym("owner is invalid")
else if (!owner.isClass || owner.isRefinementClass || denot.isSelfSym) true
else if (owner.unforcedDecls.lookupAll(denot.name) contains denot.symbol) true
else explainSym(s"decls of ${show(owner)} are ${owner.unforcedDecls.lookupAll(denot.name).toList}, do not contain ${denot.symbol}")
} catch {
case ex: StaleSymbol => explainSym(s"$ex was thrown")
}
}
case _ =>
explain("denotation is not a SymDenotation")
}
}
}
object SymDenotations {
/** A sym-denotation represents the contents of a definition
* during a period.
*/
class SymDenotation private[SymDenotations] (
symbol: Symbol,
ownerIfExists: Symbol,
final val name: Name,
initFlags: FlagSet,
final val initInfo: Type,
initPrivateWithin: Symbol = NoSymbol) extends SingleDenotation(symbol) {
//assert(symbol.id != 4940, name)
override def hasUniqueSym: Boolean = exists
/** Debug only
override def validFor_=(p: Period) = {
super.validFor_=(p)
}
*/
if (Config.checkNoSkolemsInInfo) assertNoSkolems(initInfo)
// ------ Getting and setting fields -----------------------------
private[this] var myFlags: FlagSet = adaptFlags(initFlags)
private[this] var myInfo: Type = initInfo
private[this] var myPrivateWithin: Symbol = initPrivateWithin
private[this] var myAnnotations: List[Annotation] = Nil
/** The owner of the symbol; overridden in NoDenotation */
def owner: Symbol = ownerIfExists
/** Same as owner, except returns NoSymbol for NoSymbol */
def maybeOwner: Symbol = if (exists) owner else NoSymbol
/** The flag set */
final def flags(implicit ctx: Context): FlagSet = { ensureCompleted(); myFlags }
/** The flag set without forcing symbol completion.
* Should be used only for printing.
*/
private[dotc] final def flagsUNSAFE = myFlags
/** Adapt flag set to this denotation's term or type nature */
private def adaptFlags(flags: FlagSet) = if (isType) flags.toTypeFlags else flags.toTermFlags
/** Update the flag set */
final def flags_=(flags: FlagSet): Unit =
myFlags = adaptFlags(flags)
/** Set given flags(s) of this denotation */
final def setFlag(flags: FlagSet): Unit = { myFlags |= flags }
/** Unset given flags(s) of this denotation */
final def resetFlag(flags: FlagSet): Unit = { myFlags &~= flags }
/** Set applicable flags from `flags` which is a subset of {NoInits, PureInterface} */
final def setApplicableFlags(flags: FlagSet): Unit = {
val mask = if (myFlags.is(Trait)) NoInitsInterface else NoInits
setFlag(flags & mask)
}
/** Has this denotation one of the flags in `fs` set? */
final def is(fs: FlagSet)(implicit ctx: Context) = {
(if (fs <= FromStartFlags) myFlags else flags) is fs
}
/** Has this denotation one of the flags in `fs` set, whereas none of the flags
* in `butNot` are set?
*/
final def is(fs: FlagSet, butNot: FlagSet)(implicit ctx: Context) =
(if (fs <= FromStartFlags && butNot <= FromStartFlags) myFlags else flags) is (fs, butNot)
/** Has this denotation all of the flags in `fs` set? */
final def is(fs: FlagConjunction)(implicit ctx: Context) =
(if (fs <= FromStartFlags) myFlags else flags) is fs
/** Has this denotation all of the flags in `fs` set, whereas none of the flags
* in `butNot` are set?
*/
final def is(fs: FlagConjunction, butNot: FlagSet)(implicit ctx: Context) =
(if (fs <= FromStartFlags && butNot <= FromStartFlags) myFlags else flags) is (fs, butNot)
/** The type info.
* The info is an instance of TypeType iff this is a type denotation
* Uncompleted denotations set myInfo to a LazyType.
*/
final def info(implicit ctx: Context): Type = myInfo match {
case myInfo: LazyType => completeFrom(myInfo); info
case _ => myInfo
}
/** The type info, or, if symbol is not yet completed, the completer */
final def infoOrCompleter = myInfo
/** Optionally, the info if it is completed */
final def unforcedInfo: Option[Type] = myInfo match {
case myInfo: LazyType => None
case _ => Some(myInfo)
}
private def completeFrom(completer: LazyType)(implicit ctx: Context): Unit = {
if (completions ne noPrinter) {
completions.println(i"${" " * indent}completing ${if (isType) "type" else "val"} $name")
indent += 1
}
if (myFlags is Touched) throw CyclicReference(this)
myFlags |= Touched
// completions.println(s"completing ${this.debugString}")
try completer.complete(this)(ctx.withPhase(validFor.firstPhaseId))
catch {
case ex: CyclicReference =>
completions.println(s"error while completing ${this.debugString}")
throw ex
}
finally
if (completions ne noPrinter) {
indent -= 1
completions.println(i"${" " * indent}completed $name in $owner")
}
// completions.println(s"completed ${this.debugString}")
}
protected[dotc] def info_=(tp: Type) = {
/* // DEBUG
def illegal: String = s"illegal type for $this: $tp"
if (this is Module) // make sure module invariants that allow moduleClass and sourceModule to work are kept.
tp match {
case tp: ClassInfo => assert(tp.selfInfo.isInstanceOf[TermRefBySym], illegal)
case tp: NamedType => assert(tp.isInstanceOf[TypeRefBySym], illegal)
case tp: ExprType => assert(tp.resultType.isInstanceOf[TypeRefBySym], illegal)
case _ =>
}
*/
if (Config.checkNoSkolemsInInfo) assertNoSkolems(initInfo)
myInfo = tp
}
/** The name, except
* - if this is a module class, strip the module class suffix
* - if this is a companion object with a clash-avoiding name, strip the
* "avoid clash" suffix
*/
def effectiveName(implicit ctx: Context) =
if (this is ModuleClass) name.stripModuleClassSuffix
else name.stripAvoidClashSuffix
/** The privateWithin boundary, NoSymbol if no boundary is given.
*/
final def privateWithin(implicit ctx: Context): Symbol = { ensureCompleted(); myPrivateWithin }
/** Set privateWithin. */
protected[core] final def privateWithin_=(sym: Symbol): Unit =
myPrivateWithin = sym
/** The annotations of this denotation */
final def annotations(implicit ctx: Context): List[Annotation] = {
ensureCompleted(); myAnnotations
}
/** Update the annotations of this denotation */
private[core] final def annotations_=(annots: List[Annotation]): Unit =
myAnnotations = annots
/** Does this denotation have an annotation matching the given class symbol? */
final def hasAnnotation(cls: Symbol)(implicit ctx: Context) =
dropOtherAnnotations(annotations, cls).nonEmpty
/** Apply transform `f` to all annotations of this denotation */
final def transformAnnotations(f: Annotation => Annotation)(implicit ctx: Context): Unit =
annotations = annotations.mapConserve(f)
/** Keep only those annotations that satisfy `p` */
final def filterAnnotations(p: Annotation => Boolean)(implicit ctx: Context): Unit =
annotations = annotations.filterConserve(p)
/** Optionally, the annotation matching the given class symbol */
final def getAnnotation(cls: Symbol)(implicit ctx: Context): Option[Annotation] =
dropOtherAnnotations(annotations, cls) match {
case annot :: _ => Some(annot)
case nil => None
}
/** Add given annotation to the annotations of this denotation */
final def addAnnotation(annot: Annotation): Unit =
annotations = annot :: myAnnotations
/** Remove annotation with given class from this denotation */
final def removeAnnotation(cls: Symbol)(implicit ctx: Context): Unit =
annotations = myAnnotations.filterNot(_ matches cls)
/** Add all given annotations to this symbol */
final def addAnnotations(annots: TraversableOnce[Annotation])(implicit ctx: Context): Unit =
annots.foreach(addAnnotation)
@tailrec
private def dropOtherAnnotations(anns: List[Annotation], cls: Symbol)(implicit ctx: Context): List[Annotation] = anns match {
case ann :: rest => if (ann matches cls) anns else dropOtherAnnotations(rest, cls)
case Nil => Nil
}
/** The denotation is completed: info is not a lazy type and attributes have defined values */
final def isCompleted: Boolean = !myInfo.isInstanceOf[LazyType]
/** The denotation is in train of being completed */
final def isCompleting: Boolean = (myFlags is Touched) && !isCompleted
/** The completer of this denotation. @pre: Denotation is not yet completed */
final def completer: LazyType = myInfo.asInstanceOf[LazyType]
/** Make sure this denotation is completed */
final def ensureCompleted()(implicit ctx: Context): Unit = info
/** The symbols defined in this class or object.
* Careful! This does not force the type, so is compilation order dependent.
* This method should be used only in the following circumstances:
*
* 1. When accessing type parameters or type parameter accessors (both are entered before
* completion).
* 2. When obtaining the current scope in order to enter, rename or delete something there.
* 3. When playing it safe in order not to raise CylicReferences, e.g. for printing things
* or taking more efficient shortcuts (e.g. the stillValid test).
*/
final def unforcedDecls(implicit ctx: Context): Scope = myInfo match {
case cinfo: LazyType =>
val knownDecls = cinfo.decls
if (knownDecls ne EmptyScope) knownDecls
else { completeFrom(cinfo); unforcedDecls } // complete-once
case _ => info.decls
}
/** If this is a package class, the symbols entered in it
* before it is completed. (this is needed to eagerly enter synthetic
* aliases such as AnyRef into a package class without forcing it.
* Right now, the only usage is for the AnyRef alias in Definitions.
*/
final private[core] def currentPackageDecls(implicit ctx: Context): MutableScope = myInfo match {
case pinfo: SymbolLoaders # PackageLoader => pinfo.currentDecls
case _ => unforcedDecls.openForMutations
}
// ------ Names ----------------------------------------------
/** The expanded name of this denotation. */
final def expandedName(implicit ctx: Context) =
if (is(ExpandedName) || isConstructor) name
else {
def legalize(name: Name): Name = // JVM method names may not contain `<' or `>' characters
if (is(Method)) name.replace('<', '(').replace('>', ')') else name
legalize(name.expandedName(initial.asSymDenotation.owner))
}
// need to use initial owner to disambiguate, as multiple private symbols with the same name
// might have been moved from different origins into the same class
/** The name with which the denoting symbol was created */
final def originalName(implicit ctx: Context) = {
val d = initial.asSymDenotation
if (d is ExpandedName) d.name.unexpandedName else d.name // !!!DEBUG, was: effectiveName
}
/** The encoded full path name of this denotation, where outer names and inner names
* are separated by `separator` strings.
* Never translates expansions of operators back to operator symbol.
* Drops package objects. Represents terms in the owner chain by a simple `~`.
* (Note: scalac uses nothing to represent terms, which can cause name clashes
* between same-named definitions in different enclosing methods. Before this commit
* we used `$' but this can cause ambiguities with the class separator '$').
* A separator "" means "flat name"; the real separator in this case is "$" and
* enclosing packages do not form part of the name.
*/
def fullNameSeparated(separator: String)(implicit ctx: Context): Name = {
var sep = separator
var stopAtPackage = false
if (sep.isEmpty) {
sep = "$"
stopAtPackage = true
}
if (symbol == NoSymbol ||
owner == NoSymbol ||
owner.isEffectiveRoot ||
stopAtPackage && owner.is(PackageClass)) name
else {
var encl = owner
while (!encl.isClass && !encl.isPackageObject) {
encl = encl.owner
sep += "~"
}
if (owner.is(ModuleClass, butNot = Package) && sep == "$") sep = "" // duplicate scalac's behavior: don't write a double '$$' for module class members.
val fn = encl.fullNameSeparated(separator) ++ sep ++ name
if (isType) fn.toTypeName else fn.toTermName
}
}
/** The encoded flat name of this denotation, where joined names are separated by `separator` characters. */
def flatName(implicit ctx: Context): Name = fullNameSeparated("")
/** `fullName` where `.' is the separator character */
def fullName(implicit ctx: Context): Name = fullNameSeparated(".")
// ----- Tests -------------------------------------------------
/** Is this denotation a type? */
override def isType: Boolean = name.isTypeName
/** Is this denotation a class? */
final def isClass: Boolean = isInstanceOf[ClassDenotation]
/** Is this denotation a non-trait class? */
final def isRealClass(implicit ctx: Context) = isClass && !is(Trait)
/** Cast to class denotation */
final def asClass: ClassDenotation = asInstanceOf[ClassDenotation]
/** is this symbol the result of an erroneous definition? */
def isError: Boolean = false
/** Make denotation not exist */
final def markAbsent(): Unit =
myInfo = NoType
/** Is symbol known to not exist? */
final def isAbsent(implicit ctx: Context): Boolean =
myInfo == NoType ||
(this is (ModuleVal, butNot = Package)) && moduleClass.isAbsent
/** Is this symbol the root class or its companion object? */
final def isRoot: Boolean =
(name.toTermName == nme.ROOT || name == nme.ROOTPKG) && (owner eq NoSymbol)
/** Is this symbol the empty package class or its companion object? */
final def isEmptyPackage(implicit ctx: Context): Boolean =
name.toTermName == nme.EMPTY_PACKAGE && owner.isRoot
/** Is this symbol the empty package class or its companion object? */
final def isEffectiveRoot(implicit ctx: Context) = isRoot || isEmptyPackage
/** Is this symbol an anonymous class? */
final def isAnonymousClass(implicit ctx: Context): Boolean =
isClass && (initial.asSymDenotation.name startsWith tpnme.ANON_CLASS)
final def isAnonymousFunction(implicit ctx: Context) =
this.symbol.is(Method) && (initial.asSymDenotation.name startsWith nme.ANON_FUN)
final def isAnonymousModuleVal(implicit ctx: Context) =
this.symbol.is(ModuleVal) && (initial.asSymDenotation.name startsWith nme.ANON_CLASS)
/** Is this a companion class method or companion object method?
* These methods are generated by Symbols#synthesizeCompanionMethod
* and used in SymDenotations#companionClass and
* SymDenotations#companionModule .
*/
final def isCompanionMethod(implicit ctx: Context) =
name.toTermName == nme.COMPANION_CLASS_METHOD ||
name.toTermName == nme.COMPANION_MODULE_METHOD
/** Is this a syntetic method that represents conversions between representations of a value class
* These methods are generated in ExtensionMethods
* and used in ElimErasedValueType.
*/
final def isValueClassConvertMethod(implicit ctx: Context) =
name.toTermName == nme.U2EVT ||
name.toTermName == nme.EVT2U
/** Is symbol a primitive value class? */
def isPrimitiveValueClass(implicit ctx: Context) =
maybeOwner == defn.ScalaPackageClass && defn.ScalaValueClasses().contains(symbol)
/** Is symbol a primitive numeric value class? */
def isNumericValueClass(implicit ctx: Context) =
maybeOwner == defn.ScalaPackageClass && defn.ScalaNumericValueClasses().contains(symbol)
/** Is symbol a phantom class for which no runtime representation exists? */
def isPhantomClass(implicit ctx: Context) = defn.PhantomClasses contains symbol
/** Is this symbol a class representing a refinement? These classes
* are used only temporarily in Typer and Unpickler as an intermediate
* step for creating Refinement types.
*/
final def isRefinementClass(implicit ctx: Context): Boolean =
name.decode == tpnme.REFINE_CLASS
/** Is this symbol a package object or its module class? */
def isPackageObject(implicit ctx: Context): Boolean = {
val poName = if (isType) nme.PACKAGE_CLS else nme.PACKAGE
(name.toTermName == poName) && (owner is Package) && (this is Module)
}
/** Is this symbol an abstract type? */
final def isAbstractType(implicit ctx: Context) = isType && (this is Deferred)
/** Is this symbol an alias type? */
final def isAliasType(implicit ctx: Context) = isAbstractOrAliasType && !(this is Deferred)
/** Is this symbol an abstract or alias type? */
final def isAbstractOrAliasType = isType & !isClass
/** Is this the denotation of a self symbol of some class?
* This is the case if one of two conditions holds:
* 1. It is the symbol referred to in the selfInfo part of the ClassInfo
* which is the type of this symbol's owner.
* 2. This symbol is owned by a class, it's selfInfo field refers to a type
* (indicating the self definition does not introduce a name), and the
* symbol's name is "_".
* TODO: Find a more robust way to characterize self symbols, maybe by
* spending a Flag on them?
*/
final def isSelfSym(implicit ctx: Context) = owner.infoOrCompleter match {
case ClassInfo(_, _, _, _, selfInfo) =>
selfInfo == symbol ||
selfInfo.isInstanceOf[Type] && name == nme.WILDCARD
case _ => false
}
/** Is this definition contained in `boundary`?
* Same as `ownersIterator contains boundary` but more efficient.
*/
final def isContainedIn(boundary: Symbol)(implicit ctx: Context): Boolean = {
def recur(sym: Symbol): Boolean =
if (sym eq boundary) true
else if (sym eq NoSymbol) false
else if ((sym is PackageClass) && !(boundary is PackageClass)) false
else recur(sym.owner)
recur(symbol)
}
final def isProperlyContainedIn(boundary: Symbol)(implicit ctx: Context): Boolean =
symbol != boundary && isContainedIn(boundary)
/** Is this denotation static (i.e. with no outer instance)? */
final def isStatic(implicit ctx: Context) =
(this is JavaStatic) || this.exists && owner.isStaticOwner || this.isRoot
/** Is this a package class or module class that defines static symbols? */
final def isStaticOwner(implicit ctx: Context): Boolean =
(this is PackageClass) || (this is ModuleClass) && isStatic
/** Is this denotation defined in the same scope and compilation unit as that symbol? */
final def isCoDefinedWith(that: Symbol)(implicit ctx: Context) =
(this.effectiveOwner == that.effectiveOwner) &&
( !(this.effectiveOwner is PackageClass)
|| this.isAbsent || that.isAbsent
|| { // check if they are defined in the same file(or a jar)
val thisFile = this.symbol.associatedFile
val thatFile = that.symbol.associatedFile
( thisFile == null
|| thatFile == null
|| thisFile.path == thatFile.path // Cheap possibly wrong check, then expensive normalization
|| thisFile.canonicalPath == thatFile.canonicalPath
)
}
)
/** Is this a denotation of a stable term (or an arbitrary type)? */
final def isStable(implicit ctx: Context) =
isType || is(Stable) || !(is(UnstableValue) || info.isInstanceOf[ExprType])
/** Is this a "real" method? A real method is a method which is:
* - not an accessor
* - not a label
* - not an anonymous function
* - not a companion method
*/
final def isRealMethod(implicit ctx: Context) =
this.is(Method, butNot = AccessorOrLabel) &&
!isAnonymousFunction &&
!isCompanionMethod
/** Is this a getter? */
final def isGetter(implicit ctx: Context) =
(this is Accessor) && !originalName.isSetterName && !originalName.isScala2LocalSuffix
/** Is this a setter? */
final def isSetter(implicit ctx: Context) =
(this is Accessor) &&
originalName.isSetterName &&
(!isCompleted || info.firstParamTypes.nonEmpty) // to avoid being fooled by var x_= : Unit = ...
/** is this the constructor of a class? */
final def isClassConstructor = name == nme.CONSTRUCTOR
/** Is this the constructor of a trait? */
final def isImplClassConstructor = name == nme.TRAIT_CONSTRUCTOR
/** Is this the constructor of a trait or a class */
final def isConstructor = name.isConstructorName
/** Is this a local template dummmy? */
final def isLocalDummy: Boolean = name.isLocalDummyName
/** Does this symbol denote the primary constructor of its enclosing class? */
final def isPrimaryConstructor(implicit ctx: Context) =
isConstructor && owner.primaryConstructor == symbol
/** Does this symbol denote the static constructor of its enclosing class? */
final def isStaticConstructor(implicit ctx: Context) =
name.isStaticConstructorName
/** Is this a subclass of the given class `base`? */
def isSubClass(base: Symbol)(implicit ctx: Context) = false
/** Is this a subclass of `base`,
* and is the denoting symbol also different from `Null` or `Nothing`?
* @note erroneous classes are assumed to derive from all other classes
* and all classes derive from them.
*/
def derivesFrom(base: Symbol)(implicit ctx: Context) = false
/** Is this symbol a class that extends `AnyVal`? */
final def isValueClass(implicit ctx: Context): Boolean = {
val di = this.initial.asSymDenotation
di.isClass &&
di.derivesFrom(defn.AnyValClass)(ctx.withPhase(di.validFor.firstPhaseId))
// We call derivesFrom at the initial phase both because AnyVal does not exist
// after Erasure and to avoid cyclic references caused by forcing denotations
}
/** Is this symbol a class references to which that are supertypes of null? */
final def isNullableClass(implicit ctx: Context): Boolean =
isClass && !isValueClass && !(this is ModuleClass) && symbol != defn.NothingClass
/** Is this definition accessible as a member of tree with type `pre`?
* @param pre The type of the tree from which the selection is made
* @param superAccess Access is via super
* Everything is accessible if `pre` is `NoPrefix`.
* A symbol with type `NoType` is not accessible for any other prefix.
*/
final def isAccessibleFrom(pre: Type, superAccess: Boolean = false, whyNot: StringBuffer = null)(implicit ctx: Context): Boolean = {
/** Are we inside definition of `boundary`? */
def accessWithin(boundary: Symbol) = {
def test(implicit ctx: Context) =
ctx.owner.isContainedIn(boundary) &&
(!(this is JavaDefined) || // disregard package nesting for Java
ctx.owner.enclosingPackageClass == boundary.enclosingPackageClass)
try test
catch {
// It might be we are in a definition whose symbol is not defined at the
// period where the test is made. Retry with FutureDefsOK. The reason
// for not doing this outright is speed. We would like to avoid
// creating a new context object each time we call accessWithin.
// Note that the exception should be thrown only infrequently.
case ex: NotDefinedHere => test(ctx.addMode(Mode.FutureDefsOK))
}
}
/** Are we within definition of linked class of `boundary`? */
def accessWithinLinked(boundary: Symbol) = {
val linked = boundary.linkedClass
(linked ne NoSymbol) && accessWithin(linked)
}
/** Is `pre` the same as C.thisThis, where C is exactly the owner of this symbol,
* or, if this symbol is protected, a subclass of the owner?
*/
def isCorrectThisType(pre: Type): Boolean = pre match {
case pre: ThisType =>
(pre.cls eq owner) || (this is Protected) && pre.cls.derivesFrom(owner)
case pre: TermRef =>
pre.symbol.moduleClass == owner
case _ =>
false
}
/** Is protected access to target symbol permitted? */
def isProtectedAccessOK = {
def fail(str: => String): Boolean = {
if (whyNot != null) whyNot append str
false
}
val cls = owner.enclosingSubClass
if (!cls.exists)
fail(
s""" Access to protected $this not permitted because
| enclosing ${ctx.owner.enclosingClass.showLocated} is not a subclass of
| ${owner.showLocated} where target is defined""".stripMargin)
else if (
!( isType // allow accesses to types from arbitrary subclasses fixes #4737
|| pre.baseTypeRef(cls).exists // ??? why not use derivesFrom ???
|| isConstructor
|| (owner is ModuleClass) // don't perform this check for static members
))
fail(
s""" Access to protected ${symbol.show} not permitted because
| prefix type ${pre.widen.show} does not conform to
| ${cls.showLocated} where the access takes place""".stripMargin)
else true
}
if (pre eq NoPrefix) true
else if (info eq NoType) false
else {
val boundary = accessBoundary(owner)
( boundary.isTerm
|| boundary.isRoot
|| (accessWithin(boundary) || accessWithinLinked(boundary)) &&
( !(this is Local)
|| (owner is ImplClass) // allow private local accesses to impl class members
|| isCorrectThisType(pre)
)
|| (this is Protected) &&
( superAccess
|| pre.isInstanceOf[ThisType]
|| ctx.phase.erasedTypes
|| isProtectedAccessOK
)
)
}
}
/** Do members of this symbol need translation via asSeenFrom when
* accessed via prefix `pre`?
*/
def membersNeedAsSeenFrom(pre: Type)(implicit ctx: Context) =
!( this.isTerm
|| this.isStaticOwner
|| ctx.erasedTypes
|| (pre eq NoPrefix) || (pre eq thisType)
)
/** Is this symbol concrete, or that symbol deferred? */
def isAsConcrete(that: Symbol)(implicit ctx: Context): Boolean =
!(this is Deferred) || (that is Deferred)
/** Does this symbol have defined or inherited default parameters? */
def hasDefaultParams(implicit ctx: Context): Boolean =
if (this is HasDefaultParams) true
else if (this is NoDefaultParams) false
else {
val result = allOverriddenSymbols exists (_.hasDefaultParams)
setFlag(if (result) InheritedDefaultParams else NoDefaultParams)
result
}
/** Symbol is an owner that would be skipped by effectiveOwner. Skipped are
* - package objects
* - labels
* - non-lazy valdefs
*/
def isWeakOwner(implicit ctx: Context): Boolean =
isPackageObject ||
isTerm && !is(MethodOrLazy, butNot = Label) && !isLocalDummy
// def isOverridable: Boolean = !!! need to enforce that classes cannot be redefined
def isSkolem: Boolean = name == nme.SKOLEM
// ------ access to related symbols ---------------------------------
/* Modules and module classes are represented as follows:
*
* object X extends Y { def f() }
*
* <module> lazy val X: X$ = new X$
* <module> class X$ extends Y { this: X.type => def f() }
*
* During completion, references to moduleClass and sourceModules are stored in
* the completers.
*/
/** The class implementing this module, NoSymbol if not applicable. */
final def moduleClass(implicit ctx: Context): Symbol = {
def notFound = { println(s"missing module class for $name: $myInfo"); NoSymbol }
if (this is ModuleVal)
myInfo match {
case info: TypeRef => info.symbol
case ExprType(info: TypeRef) => info.symbol // needed after uncurry, when module terms might be accessor defs
case info: LazyType => info.moduleClass
case t: MethodType =>
t.resultType match {
case info: TypeRef => info.symbol
case _ => notFound
}
case _ => notFound
}
else NoSymbol
}
/** The module implemented by this module class, NoSymbol if not applicable. */
final def sourceModule(implicit ctx: Context): Symbol = myInfo match {
case ClassInfo(_, _, _, _, selfType) if this is ModuleClass =>
selfType match {
case selfType: TermRef => selfType.symbol
case selfType: Symbol => selfType.info.asInstanceOf[TermRef].symbol
}
case info: LazyType =>
info.sourceModule
case _ =>
NoSymbol
}
/** The field accessed by this getter or setter, or if it does not exist, the getter */
def accessedFieldOrGetter(implicit ctx: Context): Symbol = {
val fieldName = if (isSetter) name.asTermName.getterName else name
val d = owner.info.decl(fieldName)
val field = d.suchThat(!_.is(Method)).symbol
def getter = d.suchThat(_.info.isParameterless).symbol
field orElse getter
}
/** The field accessed by a getter or setter, or
* if it does not exists, the getter of a setter, or
* if that does not exist the symbol itself.
*/
def underlyingSymbol(implicit ctx: Context): Symbol =
if (is(Accessor)) accessedFieldOrGetter orElse symbol else symbol
/** The chain of owners of this denotation, starting with the denoting symbol itself */
final def ownersIterator(implicit ctx: Context) = new Iterator[Symbol] {
private[this] var current = symbol
def hasNext = current.exists
def next: Symbol = {
val result = current
current = current.owner
result
}
}
/** If this is a weak owner, its owner, otherwise the denoting symbol. */
final def skipWeakOwner(implicit ctx: Context): Symbol =
if (isWeakOwner) owner.skipWeakOwner else symbol
/** The owner, skipping package objects, labels and non-lazy valdefs. */
final def effectiveOwner(implicit ctx: Context) = owner.skipWeakOwner
/** The class containing this denotation.
* If this denotation is already a class, return itself
* Definitions flagged with InSuperCall are treated specially.
* Their enclosing class is not the lexically enclosing class,
* but in turn the enclosing class of the latter. This reflects
* the context created by `Context#superCallContext`, `Context#thisCallArgContext`
* for these definitions.
*
* Note, that as packages have ClassSymbols, top level classes will have an `enclosingClass`
* with Package flag set.
*/
final def enclosingClass(implicit ctx: Context): Symbol = {
def enclClass(sym: Symbol, skip: Boolean): Symbol = {
def newSkip = sym.is(InSuperCall) || sym.is(JavaStaticTerm)
if (!sym.exists)
NoSymbol
else if (sym.isClass)
if (skip) enclClass(sym.owner, newSkip) else sym
else
enclClass(sym.owner, skip || newSkip)
}
enclClass(symbol, false)
}
/** A symbol is effectively final if it cannot be overridden in a subclass */
final def isEffectivelyFinal(implicit ctx: Context): Boolean =
is(PrivateOrFinal) || !owner.isClass || owner.is(ModuleOrFinal) || owner.isAnonymousClass
/** The class containing this denotation which has the given effective name. */
final def enclosingClassNamed(name: Name)(implicit ctx: Context): Symbol = {
val cls = enclosingClass
if (cls.effectiveName == name || !cls.exists) cls else cls.owner.enclosingClassNamed(name)
}
/** The closest enclosing method containing this definition.
* A local dummy owner is mapped to the primary constructor of the class.
*/
final def enclosingMethod(implicit ctx: Context): Symbol =
if (this is (Method, butNot = Label)) symbol
else if (this.isClass) primaryConstructor
else if (this.exists) owner.enclosingMethod
else NoSymbol
/** The top-level class containing this denotation,
* except for a toplevel module, where its module class is returned.
*/
final def topLevelClass(implicit ctx: Context): Symbol = {
def topLevel(d: SymDenotation): Symbol = {
if (d.isEffectiveRoot || (d is PackageClass) || (d.owner is PackageClass)) d.symbol
else topLevel(d.owner)
}
val sym = topLevel(this)
if (sym.isClass) sym else sym.moduleClass
}
/** The package class containing this denotation */
final def enclosingPackageClass(implicit ctx: Context): Symbol =
if (this is PackageClass) symbol else owner.enclosingPackageClass
/** The module object with the same (term-) name as this class or module class,
* and which is also defined in the same scope and compilation unit.
* NoSymbol if this module does not exist.
*/
final def companionModule(implicit ctx: Context): Symbol = {
if (this.flagsUNSAFE is Flags.Module) this.sourceModule
else {
val companionMethod = info.decls.denotsNamed(nme.COMPANION_MODULE_METHOD, selectPrivate).first
if (companionMethod.exists)
companionMethod.info.resultType.classSymbol.sourceModule
else
NoSymbol
}
}
/** The class with the same (type-) name as this module or module class,
* and which is also defined in the same scope and compilation unit.
* NoSymbol if this class does not exist.
*/
final def companionClass(implicit ctx: Context): Symbol = {
val companionMethod = info.decls.denotsNamed(nme.COMPANION_CLASS_METHOD, selectPrivate).first
if (companionMethod.exists)
companionMethod.info.resultType.classSymbol
else
NoSymbol
}
final def scalacLinkedClass(implicit ctx: Context): Symbol =
if (this is ModuleClass) companionNamed(effectiveName.toTypeName)
else if (this.isClass) companionNamed(effectiveName.moduleClassName).sourceModule.moduleClass
else NoSymbol
/** Find companion class symbol with given name, or NoSymbol if none exists.
* Three alternative strategies:
* 1. If owner is a class, look in its members, otherwise
* 2. If current compilation unit has a typed tree,
* determine the defining statement sequence and search its trees, otherwise
* 3. If context has an enclosing scope which defines this symbol,
* lookup its companion in the same scope.
*/
private def companionNamed(name: TypeName)(implicit ctx: Context): Symbol =
if (owner.isClass)
owner.info.decl(name).suchThat(_.isCoDefinedWith(symbol)).symbol
else if (!owner.exists || ctx.compilationUnit == null)
NoSymbol
else if (!ctx.compilationUnit.tpdTree.isEmpty)
tpd.definingStats(symbol).iterator
.map(tpd.definedSym)
.find(_.name == name)
.getOrElse(NoSymbol)
else if (ctx.scope == null)
NoSymbol
else if (ctx.scope.lookup(this.name) == symbol)
ctx.scope.lookup(name)
else
companionNamed(name)(ctx.outersIterator.dropWhile(_.scope eq ctx.scope).next)
/** If this is a class, the module class of its companion object.
* If this is a module class, its companion class.
* NoSymbol otherwise.
*/
final def linkedClass(implicit ctx: Context): Symbol =
if (this is ModuleClass) companionClass
else if (this.isClass) companionModule.moduleClass
else NoSymbol
/** The class that encloses the owner of the current context
* and that is a subclass of this class. NoSymbol if no such class exists.
*/
final def enclosingSubClass(implicit ctx: Context) =
ctx.owner.ownersIterator.findSymbol(_.isSubClass(symbol))
/** The non-private symbol whose name and type matches the type of this symbol
* in the given class.
* @param inClass The class containing the result symbol's definition
* @param site The base type from which member types are computed
*
* inClass <-- find denot.symbol class C { <-- symbol is here
*
* site: Subtype of both inClass and C
*/
final def matchingDecl(inClass: Symbol, site: Type)(implicit ctx: Context): Symbol = {
var denot = inClass.info.nonPrivateDecl(name)
if (denot.isTerm) // types of the same name always match
denot = denot.matchingDenotation(site, site.memberInfo(symbol))
denot.symbol
}
/** The non-private member of `site` whose name and type matches the type of this symbol
*/
final def matchingMember(site: Type)(implicit ctx: Context): Symbol = {
var denot = site.nonPrivateMember(name)
if (denot.isTerm) // types of the same name always match
denot = denot.matchingDenotation(site, site.memberInfo(symbol))
denot.symbol
}
/** If false, this symbol cannot possibly participate in an override,
* either as overrider or overridee.
*/
final def canMatchInheritedSymbols(implicit ctx: Context): Boolean =
maybeOwner.isClass && memberCanMatchInheritedSymbols
/** If false, this class member cannot possibly participate in an override,
* either as overrider or overridee.
*/
final def memberCanMatchInheritedSymbols(implicit ctx: Context): Boolean =
!isConstructor && !is(Private)
/** The symbol, in class `inClass`, that is overridden by this denotation. */
final def overriddenSymbol(inClass: ClassSymbol)(implicit ctx: Context): Symbol =
if (!canMatchInheritedSymbols && (owner ne inClass)) NoSymbol
else matchingDecl(inClass, owner.thisType)
/** All symbols overriden by this denotation. */
final def allOverriddenSymbols(implicit ctx: Context): Iterator[Symbol] =
if (!canMatchInheritedSymbols) Iterator.empty
else overriddenFromType(owner.info)
/** Returns all matching symbols defined in parents of the selftype. */
final def extendedOverriddenSymbols(implicit ctx: Context): Iterator[Symbol] =
if (!canMatchInheritedSymbols) Iterator.empty
else overriddenFromType(owner.asClass.classInfo.selfType)
private def overriddenFromType(tp: Type)(implicit ctx: Context): Iterator[Symbol] =
tp.baseClasses.tail.iterator map overriddenSymbol filter (_.exists)
/** The symbol overriding this symbol in given subclass `ofclazz`.
*
* @param ofclazz is a subclass of this symbol's owner
*/
final def overridingSymbol(inClass: ClassSymbol)(implicit ctx: Context): Symbol =
if (canMatchInheritedSymbols) matchingDecl(inClass, inClass.thisType)
else NoSymbol
/** The symbol accessed by a super in the definition of this symbol when
* seen from class `base`. This symbol is always concrete.
* pre: `this.owner` is in the base class sequence of `base`.
*/
final def superSymbolIn(base: Symbol)(implicit ctx: Context): Symbol = {
def loop(bcs: List[ClassSymbol]): Symbol = bcs match {
case bc :: bcs1 =>
val sym = matchingDecl(bcs.head, base.thisType)
.suchThat(alt => !(alt is Deferred)).symbol
if (sym.exists) sym else loop(bcs.tail)
case _ =>
NoSymbol
}
loop(base.info.baseClasses.dropWhile(owner != _).tail)
}
/** A member of class `base` is incomplete if
* (1) it is declared deferred or
* (2) it is abstract override and its super symbol in `base` is
* nonexistent or incomplete.
*/
final def isIncompleteIn(base: Symbol)(implicit ctx: Context): Boolean =
(this is Deferred) ||
(this is AbsOverride) && {
val supersym = superSymbolIn(base)
supersym == NoSymbol || supersym.isIncompleteIn(base)
}
/** The class or term symbol up to which this symbol is accessible,
* or RootClass if it is public. As java protected statics are
* otherwise completely inaccessible in scala, they are treated
* as public.
* @param base The access boundary to assume if this symbol is protected
*/
final def accessBoundary(base: Symbol)(implicit ctx: Context): Symbol = {
val fs = flags
if (fs is Private) owner
else if (fs is StaticProtected) defn.RootClass
else if (privateWithin.exists && !ctx.phase.erasedTypes) privateWithin
else if (fs is Protected) base
else defn.RootClass
}
/** The primary constructor of a class or trait, NoSymbol if not applicable. */
def primaryConstructor(implicit ctx: Context): Symbol = NoSymbol
// ----- type-related ------------------------------------------------
/** The type parameters of a class symbol, Nil for all other symbols */
def typeParams(implicit ctx: Context): List[TypeSymbol] = Nil
/** The named type parameters declared or inherited by this symbol */
def namedTypeParams(implicit ctx: Context): Set[TypeSymbol] = Set()
/** The type This(cls), where cls is this class, NoPrefix for all other symbols */
def thisType(implicit ctx: Context): Type = NoPrefix
override def typeRef(implicit ctx: Context): TypeRef =
TypeRef(owner.thisType, name.asTypeName, this)
override def termRef(implicit ctx: Context): TermRef =
TermRef(owner.thisType, name.asTermName, this)
override def valRef(implicit ctx: Context): TermRef =
TermRef.withSigAndDenot(owner.thisType, name.asTermName, Signature.NotAMethod, this)
override def termRefWithSig(implicit ctx: Context): TermRef =
TermRef.withSigAndDenot(owner.thisType, name.asTermName, signature, this)
def nonMemberTermRef(implicit ctx: Context): TermRef =
TermRef.withFixedSym(owner.thisType, name.asTermName, symbol.asTerm)
/** The variance of this type parameter or type member as an Int, with
* +1 = Covariant, -1 = Contravariant, 0 = Nonvariant, or not a type parameter
*/
final def variance(implicit ctx: Context): Int =
if (this is Covariant) 1
else if (this is Contravariant) -1
else 0
/** The flags to be used for a type parameter owned by this symbol.
* Overridden by ClassDenotation.
*/
def typeParamCreationFlags: FlagSet = TypeParam
override def toString = {
val kindString =
if (myFlags is ModuleClass) "module class"
else if (isClass) "class"
else if (isType) "type"
else if (myFlags is Module) "module"
else if (myFlags is Method) "method"
else "val"
s"$kindString $name"
}
// ----- Sanity checks and debugging */
def debugString = toString + "#" + symbol.id // !!! DEBUG
def hasSkolems(tp: Type): Boolean = tp match {
case tp: SkolemType => true
case tp: NamedType => hasSkolems(tp.prefix)
case tp: RefinedType => hasSkolems(tp.parent) || hasSkolems(tp.refinedInfo)
case tp: RecType => hasSkolems(tp.parent)
case tp: GenericType => tp.paramBounds.exists(hasSkolems) || hasSkolems(tp.resType)
case tp: MethodType => tp.paramTypes.exists(hasSkolems) || hasSkolems(tp.resType)
case tp: ExprType => hasSkolems(tp.resType)
case tp: HKApply => hasSkolems(tp.tycon) || tp.args.exists(hasSkolems)
case tp: AndOrType => hasSkolems(tp.tp1) || hasSkolems(tp.tp2)
case tp: TypeBounds => hasSkolems(tp.lo) || hasSkolems(tp.hi)
case tp: AnnotatedType => hasSkolems(tp.tpe)
case tp: TypeVar => hasSkolems(tp.inst)
case _ => false
}
def assertNoSkolems(tp: Type) =
if (!this.isSkolem)
assert(!hasSkolems(tp), s"assigning type $tp containing skolems to $this")
// ----- copies and transforms ----------------------------------------
protected def newLikeThis(s: Symbol, i: Type): SingleDenotation = new UniqueRefDenotation(s, i, validFor)
/** Copy this denotation, overriding selective fields */
final def copySymDenotation(
symbol: Symbol = this.symbol,
owner: Symbol = this.owner,
name: Name = this.name,
initFlags: FlagSet = UndefinedFlags,
info: Type = null,
privateWithin: Symbol = null,
annotations: List[Annotation] = null)(implicit ctx: Context) =
{ // simulate default parameters, while also passing implicit context ctx to the default values
val initFlags1 = (if (initFlags != UndefinedFlags) initFlags else this.flags) &~ Frozen
val info1 = if (info != null) info else this.info
val privateWithin1 = if (privateWithin != null) privateWithin else this.privateWithin
val annotations1 = if (annotations != null) annotations else this.annotations
val d = ctx.SymDenotation(symbol, owner, name, initFlags1, info1, privateWithin1)
d.annotations = annotations1
d
}
/** Install this denotation as the result of the given denotation transformer. */
override def installAfter(phase: DenotTransformer)(implicit ctx: Context): Unit =
super.installAfter(phase)
/** Apply a transformation `f` to all denotations in this group that start at or after
* given phase. Denotations are replaced while keeping the same validity periods.
*/
override def transformAfter(phase: DenotTransformer, f: SymDenotation => SymDenotation)(implicit ctx: Context): Unit =
super.transformAfter(phase, f)
/** If denotation is private, remove the Private flag and expand the name if necessary */
def ensureNotPrivate(implicit ctx: Context) =
if (is(Private))
copySymDenotation(
name = expandedName,
initFlags = this.flags &~ Private | ExpandedName)
else this
}
/** The contents of a class definition during a period
*/
class ClassDenotation private[SymDenotations] (
symbol: Symbol,
ownerIfExists: Symbol,
name: Name,
initFlags: FlagSet,
initInfo: Type,
initPrivateWithin: Symbol,
initRunId: RunId)
extends SymDenotation(symbol, ownerIfExists, name, initFlags, initInfo, initPrivateWithin) {
import util.LRUCache
// ----- denotation fields and accessors ------------------------------
if (initFlags is (Module, butNot = Package)) assert(name.isModuleClassName, s"module naming inconsistency: $name")
/** The symbol asserted to have type ClassSymbol */
def classSymbol: ClassSymbol = symbol.asInstanceOf[ClassSymbol]
/** The info asserted to have type ClassInfo */
def classInfo(implicit ctx: Context): ClassInfo = info.asInstanceOf[ClassInfo]
/** TODO: Document why caches are supposedly safe to use */
private[this] var myTypeParams: List[TypeSymbol] = _
private[this] var myNamedTypeParams: Set[TypeSymbol] = _
/** The type parameters in this class, in the order they appear in the current
* scope `decls`. This is might be temporarily the incorrect order when
* reading Scala2 pickled info. The problem is fixed by `updateTypeParams`
* which is called once an unpickled symbol has been completed.
*/
private def typeParamsFromDecls(implicit ctx: Context) =
unforcedDecls.filter(sym =>
(sym is TypeParam) && sym.owner == symbol).asInstanceOf[List[TypeSymbol]]
/** The type parameters of this class */
override final def typeParams(implicit ctx: Context): List[TypeSymbol] = {
if (myTypeParams == null)
myTypeParams =
if (ctx.erasedTypes || is(Module)) Nil // fast return for modules to avoid scanning package decls
else if (this ne initial) initial.asSymDenotation.typeParams
else infoOrCompleter match {
case info: TypeParamsCompleter => info.completerTypeParams(symbol)
case _ => typeParamsFromDecls
}
myTypeParams
}
/** The named type parameters declared or inherited by this class */
override final def namedTypeParams(implicit ctx: Context): Set[TypeSymbol] = {
def computeNamedTypeParams: Set[TypeSymbol] =
if (ctx.erasedTypes || is(Module)) Set() // fast return for modules to avoid scanning package decls
else memberNames(abstractTypeNameFilter).map(name =>
info.member(name).symbol.asType).filter(_.is(TypeParam, butNot = ExpandedName)).toSet
if (myNamedTypeParams == null) myNamedTypeParams = computeNamedTypeParams
myNamedTypeParams
}
override protected[dotc] final def info_=(tp: Type) = {
super.info_=(tp)
myTypeParams = null // changing the info might change decls, and with it typeParams
}
/** The denotations of all parents in this class. */
def classParents(implicit ctx: Context): List[TypeRef] = info match {
case classInfo: ClassInfo => classInfo.classParents
case _ => Nil
}
/** The symbol of the superclass, NoSymbol if no superclass exists */
def superClass(implicit ctx: Context): Symbol = classParents match {
case parent :: _ =>
val cls = parent.classSymbol
if (cls is Trait) NoSymbol else cls
case _ =>
NoSymbol
}
/** The denotation is fully completed: all attributes are fully defined.
* ClassDenotations compiled from source are first completed, then fully completed.
* Packages are never fully completed since members can be added at any time.
* @see Namer#ClassCompleter
*/
private def isFullyCompleted(implicit ctx: Context): Boolean = {
def isFullyCompletedRef(tp: TypeRef) = tp.denot match {
case d: ClassDenotation => d.isFullyCompleted
case _ => false
}
def testFullyCompleted =
if (classParents.isEmpty) !is(Package) && symbol.eq(defn.AnyClass)
else classParents.forall(isFullyCompletedRef)
flagsUNSAFE.is(FullyCompleted) ||
isCompleted && testFullyCompleted && { setFlag(FullyCompleted); true }
}
// ------ syncing inheritance-related info -----------------------------
private var firstRunId: RunId = initRunId
/** invalidate caches influenced by parent classes if one of the parents
* is younger than the denotation itself.
*/
override def syncWithParents(implicit ctx: Context): SingleDenotation = {
def isYounger(tref: TypeRef) = tref.symbol.denot match {
case denot: ClassDenotation =>
if (denot.validFor.runId < ctx.runId) denot.current // syncs with its parents in turn
val result = denot.firstRunId > this.firstRunId
if (result) incremental.println(s"$denot is younger than $this")
result
case _ => false
}
val parentIsYounger = (firstRunId < ctx.runId) && {
infoOrCompleter match {
case cinfo: ClassInfo => cinfo.classParents exists isYounger
case _ => false
}
}
if (parentIsYounger) {
incremental.println(s"parents of $this are invalid; symbol id = ${symbol.id}, copying ...\n")
invalidateInheritedInfo()
}
firstRunId = ctx.runId
this
}
/** Invalidate all caches and fields that depend on base classes and their contents */
override def invalidateInheritedInfo(): Unit = {
myBaseClasses = null
mySuperClassBits = null
myMemberFingerPrint = FingerPrint.unknown
myMemberCache = null
myMemberCachePeriod = Nowhere
memberNamesCache = SimpleMap.Empty
}
// ------ class-specific operations -----------------------------------
private[this] var myThisType: Type = null
/** The this-type depends on the kind of class:
* - for a package class `p`: ThisType(TypeRef(Noprefix, p))
* - for a module class `m`: A term ref to m's source module.
* - for all other classes `c` with owner `o`: ThisType(TypeRef(o.thisType, c))
*/
override def thisType(implicit ctx: Context): Type = {
if (myThisType == null) myThisType = computeThisType
myThisType
}
private def computeThisType(implicit ctx: Context): Type =
ThisType.raw(
TypeRef(if (this is Package) NoPrefix else owner.thisType, symbol.asType))
/* else {
val pre = owner.thisType
if (this is Module)
if (isMissing(pre)) TermRef(pre, sourceModule.asTerm)
else TermRef.withSig(pre, name.sourceModuleName, Signature.NotAMethod)
else ThisType.raw(TypeRef(pre, symbol.asType))
}
*/
private[this] var myTypeRef: TypeRef = null
override def typeRef(implicit ctx: Context): TypeRef = {
if (myTypeRef == null) myTypeRef = super.typeRef
myTypeRef
}
private[this] var myBaseClasses: List[ClassSymbol] = null
private[this] var mySuperClassBits: BitSet = null
/** Invalidate baseTypeRefCache, baseClasses and superClassBits on new run */
private def checkBasesUpToDate()(implicit ctx: Context) =
if (baseTypeRefValid != ctx.runId) {
baseTypeRefCache = new java.util.HashMap[CachedType, Type]
myBaseClasses = null
mySuperClassBits = null
baseTypeRefValid = ctx.runId
}
private def computeBases(implicit ctx: Context): (List[ClassSymbol], BitSet) = {
if (myBaseClasses eq Nil) throw CyclicReference(this)
myBaseClasses = Nil
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 bcs1added = addBaseClasses(bcs1, to)
val id = bc.superId
if (seen contains id) bcs1added
else {
seen += id
bc :: bcs1added
}
case nil =>
to
}
def addParentBaseClasses(ps: List[Type], to: List[ClassSymbol]): List[ClassSymbol] = ps match {
case p :: ps1 =>
addParentBaseClasses(ps1, addBaseClasses(p.baseClasses, to))
case nil =>
to
}
val bcs = classSymbol :: addParentBaseClasses(classParents, Nil)
val scbits = seen.toImmutable
if (isFullyCompleted) {
myBaseClasses = bcs
mySuperClassBits = scbits
}
else myBaseClasses = null
(bcs, scbits)
}
/** A bitset that contains the superId's of all base classes */
private def superClassBits(implicit ctx: Context): BitSet =
if (classParents.isEmpty) BitSet() // can happen when called too early in Namers
else {
checkBasesUpToDate()
if (mySuperClassBits != null) mySuperClassBits else computeBases._2
}
/** The base classes of this class in linearization order,
* with the class itself as first element.
*/
def baseClasses(implicit ctx: Context): List[ClassSymbol] =
if (classParents.isEmpty) classSymbol :: Nil // can happen when called too early in Namers
else {
checkBasesUpToDate()
if (myBaseClasses != null) myBaseClasses else computeBases._1
}
final override def derivesFrom(base: Symbol)(implicit ctx: Context): Boolean =
!isAbsent &&
base.isClass &&
( (symbol eq base)
|| (superClassBits contains base.superId)
|| (this is Erroneous)
|| (base is Erroneous)
)
final override def isSubClass(base: Symbol)(implicit ctx: Context) =
derivesFrom(base) ||
base.isClass && (
(symbol eq defn.NothingClass) ||
(symbol eq defn.NullClass) && (base ne defn.NothingClass))
final override def typeParamCreationFlags = ClassTypeParamCreationFlags
private[this] var myMemberFingerPrint: FingerPrint = FingerPrint.unknown
private def computeMemberFingerPrint(implicit ctx: Context): FingerPrint = {
var fp = FingerPrint()
var e = info.decls.lastEntry
while (e != null) {
fp.include(e.name)
e = e.prev
}
var ps = classParents
while (ps.nonEmpty) {
val parent = ps.head.typeSymbol
parent.denot match {
case parentDenot: ClassDenotation =>
fp.include(parentDenot.memberFingerPrint)
if (parentDenot.isFullyCompleted) parentDenot.setFlag(Frozen)
case _ =>
}
ps = ps.tail
}
fp
}
/** A bloom filter for the names of all members in this class.
* Makes sense only for parent classes, and should definitely
* not be used for package classes because cache never
* gets invalidated.
*/
def memberFingerPrint(implicit ctx: Context): FingerPrint =
if (myMemberFingerPrint != FingerPrint.unknown) myMemberFingerPrint
else {
val fp = computeMemberFingerPrint
if (isFullyCompleted) myMemberFingerPrint = fp
fp
}
private[this] var myMemberCache: LRUCache[Name, PreDenotation] = null
private[this] var myMemberCachePeriod: Period = Nowhere
private def memberCache(implicit ctx: Context): LRUCache[Name, PreDenotation] = {
if (myMemberCachePeriod != ctx.period) {
myMemberCache = new LRUCache
myMemberCachePeriod = ctx.period
}
myMemberCache
}
/** Enter a symbol in current scope, and future scopes of same denotation.
* Note: We require that this does not happen after the first time
* someone does a findMember on a subclass.
* @param scope The scope in which symbol should be entered.
* If this is EmptyScope, the scope is `decls`.
*/
def enter(sym: Symbol, scope: Scope = EmptyScope)(implicit ctx: Context): Unit = {
val mscope = scope match {
case scope: MutableScope =>
// if enter gets a scope as an argument,
// than this is a scope that will eventually become decls of this symbol.
// And this should only happen if this is first time the scope of symbol
// is computed, ie symbol yet has no future.
assert(this.nextInRun.validFor.code <= this.validFor.code)
scope
case _ => unforcedDecls.openForMutations
}
if (this is PackageClass) {
val entry = mscope.lookupEntry(sym.name)
if (entry != null) {
if (entry.sym == sym) return
mscope.unlink(entry)
entry.sym.denot = sym.denot // to avoid stale symbols
}
}
enterNoReplace(sym, mscope)
val nxt = this.nextInRun
if (nxt.validFor.code > this.validFor.code) {
this.nextInRun.asSymDenotation.asClass.enter(sym)
}
}
/** Enter a symbol in given `scope` without potentially replacing the old copy. */
def enterNoReplace(sym: Symbol, scope: MutableScope)(implicit ctx: Context): Unit = {
require((sym.denot.flagsUNSAFE is Private) || !(this is Frozen) || (scope ne this.unforcedDecls) || sym.hasAnnotation(defn.ScalaStaticAnnot))
scope.enter(sym)
if (myMemberFingerPrint != FingerPrint.unknown)
myMemberFingerPrint.include(sym.name)
if (myMemberCache != null)
myMemberCache invalidate sym.name
}
/** Replace symbol `prev` (if defined in current class) by symbol `replacement`.
* If `prev` is not defined in current class, do nothing.
* @pre `prev` and `replacement` have the same name.
*/
def replace(prev: Symbol, replacement: Symbol)(implicit ctx: Context): Unit = {
require(!(this is Frozen))
unforcedDecls.openForMutations.replace(prev, replacement)
if (myMemberCache != null)
myMemberCache invalidate replacement.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(!(this is Frozen))
info.decls.openForMutations.unlink(sym)
myMemberFingerPrint = FingerPrint.unknown
if (myMemberCache != null) myMemberCache invalidate sym.name
}
/** Make sure the type parameters of this class appear in the order given
* by `tparams` in the scope of the class. Reorder definitions in scope if necessary.
* @pre All type parameters in `tparams` are entered in class scope `info.decls`.
*/
def updateTypeParams(tparams: List[Symbol])(implicit ctx: Context): Unit =
if (!ctx.erasedTypes && !typeParamsFromDecls.corresponds(typeParams)(_.name == _.name)) {
val decls = info.decls
val decls1 = newScope
for (tparam <- tparams) decls1.enter(decls.lookup(tparam.name))
for (sym <- decls) if (!tparams.contains(sym)) decls1.enter(sym)
info = classInfo.derivedClassInfo(decls = decls1)
myTypeParams = null
}
/** All members of this class that have the given name.
* The elements of the returned pre-denotation all
* have existing symbols.
*/
final def membersNamed(name: Name)(implicit ctx: Context): PreDenotation = {
val privates = info.decls.denotsNamed(name, selectPrivate)
privates union nonPrivateMembersNamed(name).filterDisjoint(privates)
}
/** All non-private members of this class that have the given name.
* The elements of the returned pre-denotation all
* have existing symbols.
* @param inherited The method is called on a parent class from computeNPMembersNamed
*/
final def nonPrivateMembersNamed(name: Name, inherited: Boolean = false)(implicit ctx: Context): PreDenotation = {
Stats.record("nonPrivateMembersNamed")
if (Config.cacheMembersNamed) {
var denots: PreDenotation = memberCache lookup name
if (denots == null) {
denots = computeNPMembersNamed(name, inherited)
if (isFullyCompleted) memberCache.enter(name, denots)
} else if (Config.checkCacheMembersNamed) {
val denots1 = computeNPMembersNamed(name, inherited)
assert(denots.exists == denots1.exists, s"cache inconsistency: cached: $denots, computed $denots1, name = $name, owner = $this")
}
denots
} else computeNPMembersNamed(name, inherited)
}
private[core] def computeNPMembersNamed(name: Name, inherited: Boolean)(implicit ctx: Context): PreDenotation = /*>|>*/ Stats.track("computeNPMembersNamed") /*<|<*/ {
if (!inherited ||
!Config.useFingerPrints ||
(memberFingerPrint contains name)) {
Stats.record("computeNPMembersNamed after fingerprint")
ensureCompleted()
val ownDenots = info.decls.denotsNamed(name, selectNonPrivate)
if (debugTrace) // DEBUG
println(s"$this.member($name), ownDenots = $ownDenots")
def collect(denots: PreDenotation, parents: List[TypeRef]): PreDenotation = parents match {
case p :: ps =>
val denots1 = collect(denots, ps)
p.symbol.denot match {
case parentd: ClassDenotation =>
denots1 union
parentd.nonPrivateMembersNamed(name, inherited = true)
.mapInherited(ownDenots, denots1, thisType)
case _ =>
denots1
}
case nil =>
denots
}
if (name.isConstructorName) ownDenots
else collect(ownDenots, classParents)
} else NoDenotation
}
override final def findMember(name: Name, pre: Type, excluded: FlagSet)(implicit ctx: Context): Denotation = {
val raw = if (excluded is Private) nonPrivateMembersNamed(name) else membersNamed(name)
raw.filterExcluded(excluded).asSeenFrom(pre).toDenot(pre)
}
private[this] var baseTypeRefCache: java.util.HashMap[CachedType, Type] = null
private[this] var baseTypeRefValid: RunId = NoRunId
/** Compute tp.baseTypeRef(this) */
final def baseTypeRefOf(tp: Type)(implicit ctx: Context): Type = {
def foldGlb(bt: Type, ps: List[Type]): Type = ps match {
case p :: ps1 => foldGlb(bt & baseTypeRefOf(p), ps1)
case _ => bt
}
def inCache(tp: Type) = baseTypeRefCache.containsKey(tp)
/** We cannot cache:
* - type variables which are uninstantiated or whose instances can
* change, depending on typerstate.
* - types where the underlying type is an ErasedValueType, because
* this underlying type will change after ElimErasedValueType,
* and this changes subtyping relations. As a shortcut, we do not
* cache ErasedValueType at all.
*/
def isCachable(tp: Type): Boolean = tp match {
case _: TypeErasure.ErasedValueType => false
case tp: TypeVar => tp.inst.exists && inCache(tp.inst)
case tp: TypeProxy => inCache(tp.underlying)
case tp: AndOrType => inCache(tp.tp1) && inCache(tp.tp2)
case _ => true
}
def computeBaseTypeRefOf(tp: Type): Type = {
Stats.record("computeBaseTypeOf")
if (symbol.isStatic && tp.derivesFrom(symbol))
symbol.typeRef
else tp match {
case tp: TypeRef =>
val subcls = tp.symbol
if (subcls eq symbol)
tp
else subcls.denot match {
case cdenot: ClassDenotation =>
if (cdenot.superClassBits contains symbol.superId) foldGlb(NoType, tp.parents)
else NoType
case _ =>
baseTypeRefOf(tp.superType)
}
case tp: TypeProxy =>
baseTypeRefOf(tp.superType)
case AndType(tp1, tp2) =>
baseTypeRefOf(tp1) & baseTypeRefOf(tp2)
case OrType(tp1, tp2) =>
baseTypeRefOf(tp1) | baseTypeRefOf(tp2)
case JavaArrayType(_) if symbol == defn.ObjectClass =>
this.typeRef
case _ =>
NoType
}
}
/*>|>*/ ctx.debugTraceIndented(s"$tp.baseTypeRef($this)") /*<|<*/ {
tp match {
case tp: CachedType =>
checkBasesUpToDate()
var basetp = baseTypeRefCache get tp
if (basetp == null) {
baseTypeRefCache.put(tp, NoPrefix)
basetp = computeBaseTypeRefOf(tp)
if (isCachable(tp)) baseTypeRefCache.put(tp, basetp)
else baseTypeRefCache.remove(tp)
} else if (basetp == NoPrefix) {
baseTypeRefCache.put(tp, null)
throw CyclicReference(this)
}
basetp
case _ =>
computeBaseTypeRefOf(tp)
}
}
}
private[this] var memberNamesCache: SimpleMap[NameFilter, Set[Name]] = SimpleMap.Empty
def memberNames(keepOnly: NameFilter)(implicit ctx: Context): Set[Name] = {
def computeMemberNames: Set[Name] = {
var names = Set[Name]()
def maybeAdd(name: Name) = if (keepOnly(thisType, name)) names += name
for (p <- classParents)
for (name <- p.memberNames(keepOnly, thisType)) maybeAdd(name)
val ownSyms =
if (keepOnly == implicitFilter)
if (this is Package) Iterator.empty
else info.decls.iterator filter (_ is Implicit)
else info.decls.iterator
for (sym <- ownSyms) maybeAdd(sym.name)
names
}
if ((this is PackageClass) || !Config.cacheMemberNames)
computeMemberNames // don't cache package member names; they might change
else {
val cached = memberNamesCache(keepOnly)
if (cached != null) cached
else {
val names = computeMemberNames
if (isFullyCompleted) {
setFlag(Frozen)
memberNamesCache = memberNamesCache.updated(keepOnly, names)
}
names
}
}
}
private[this] var fullNameCache: SimpleMap[String, Name] = SimpleMap.Empty
override final def fullNameSeparated(separator: String)(implicit ctx: Context): Name = {
val cached = fullNameCache(separator)
if (cached != null) cached
else {
val fn = super.fullNameSeparated(separator)
fullNameCache = fullNameCache.updated(separator, fn)
fn
}
}
// to avoid overloading ambiguities
override def fullName(implicit ctx: Context): Name = super.fullName
override def primaryConstructor(implicit ctx: Context): Symbol = {
def constrNamed(cname: TermName) = info.decls.denotsNamed(cname).last.symbol
// denotsNamed returns Symbols in reverse order of occurrence
if (this.is(ImplClass)) constrNamed(nme.TRAIT_CONSTRUCTOR) // ignore normal constructor
else
constrNamed(nme.CONSTRUCTOR).orElse(constrNamed(nme.TRAIT_CONSTRUCTOR))
}
/** The parameter accessors of this class. Term and type accessors,
* getters and setters are all returned int his list
*/
def paramAccessors(implicit ctx: Context): List[Symbol] =
unforcedDecls.filter(_ is ParamAccessor).toList
/** If this class has the same `decls` scope reference in `phase` and
* `phase.next`, install a new denotation with a cloned scope in `phase.next`.
*/
def ensureFreshScopeAfter(phase: DenotTransformer)(implicit ctx: Context): Unit =
if (ctx.phaseId != phase.next.id) ensureFreshScopeAfter(phase)(ctx.withPhase(phase.next))
else {
val prevCtx = ctx.withPhase(phase)
val ClassInfo(pre, _, ps, decls, selfInfo) = classInfo
if (classInfo(prevCtx).decls eq decls)
copySymDenotation(info = ClassInfo(pre, classSymbol, ps, decls.cloneScope, selfInfo))
.installAfter(phase)
}
}
/** The denotation of a package class.
* It overrides ClassDenotation to take account of package objects when looking for members
*/
class PackageClassDenotation private[SymDenotations] (
symbol: Symbol,
ownerIfExists: Symbol,
name: Name,
initFlags: FlagSet,
initInfo: Type,
initPrivateWithin: Symbol,
initRunId: RunId)
extends ClassDenotation(symbol, ownerIfExists, name, initFlags, initInfo, initPrivateWithin, initRunId) {
private[this] var packageObjCache: SymDenotation = _
private[this] var packageObjRunId: RunId = NoRunId
/** The package object in this class, of one exists */
def packageObj(implicit ctx: Context): SymDenotation = {
if (packageObjRunId != ctx.runId) {
packageObjRunId = ctx.runId
packageObjCache = NoDenotation // break cycle in case we are looking for package object itself
packageObjCache = findMember(nme.PACKAGE, thisType, EmptyFlags).asSymDenotation
}
packageObjCache
}
/** Look first for members in package; if none are found look in package object */
override def computeNPMembersNamed(name: Name, inherited: Boolean)(implicit ctx: Context): PreDenotation = {
val denots = super.computeNPMembersNamed(name, inherited)
if (denots.exists) denots
else packageObj.moduleClass.denot match {
case pcls: ClassDenotation => pcls.computeNPMembersNamed(name, inherited)
case _ => denots
}
}
/** The union of the member names of the package and the package object */
override def memberNames(keepOnly: NameFilter)(implicit ctx: Context): Set[Name] = {
val ownNames = super.memberNames(keepOnly)
packageObj.moduleClass.denot match {
case pcls: ClassDenotation => ownNames union pcls.memberNames(keepOnly)
case _ => ownNames
}
}
}
class NoDenotation extends SymDenotation(
NoSymbol, NoSymbol, "<none>".toTermName, Permanent, NoType) {
override def exists = false
override def isTerm = false
override def isType = false
override def owner: Symbol = throw new AssertionError("NoDenotation.owner")
override def computeAsSeenFrom(pre: Type)(implicit ctx: Context): SingleDenotation = this
validFor = Period.allInRun(NoRunId) // will be brought forward automatically
}
@sharable val NoDenotation = new NoDenotation
@sharable val NotDefinedHereDenotation = new NoDenotation
// ---- Completion --------------------------------------------------------
/** Instances of LazyType are carried by uncompleted symbols.
* Note: LazyTypes double up as (constant) functions from Symbol and
* from (TermSymbol, ClassSymbol) to LazyType. That way lazy types can be
* directly passed to symbol creation methods in Symbols that demand instances
* of these function types.
*/
abstract class LazyType extends UncachedGroundType
with (Symbol => LazyType)
with ((TermSymbol, ClassSymbol) => LazyType) { self =>
/** Sets all missing fields of given denotation */
def complete(denot: SymDenotation)(implicit ctx: Context): Unit
def apply(sym: Symbol) = this
def apply(module: TermSymbol, modcls: ClassSymbol) = this
private var myDecls: Scope = EmptyScope
private var mySourceModuleFn: Context => Symbol = NoSymbolFn
private var myModuleClassFn: Context => Symbol = NoSymbolFn
/** A proxy to this lazy type that keeps the complete operation
* but provides fresh slots for scope/sourceModule/moduleClass
*/
def proxy: LazyType = new LazyType {
override def complete(denot: SymDenotation)(implicit ctx: Context) = self.complete(denot)
}
def decls: Scope = myDecls
def sourceModule(implicit ctx: Context): Symbol = mySourceModuleFn(ctx)
def moduleClass(implicit ctx: Context): Symbol = myModuleClassFn(ctx)
def withDecls(decls: Scope): this.type = { myDecls = decls; this }
def withSourceModule(sourceModuleFn: Context => Symbol): this.type = { mySourceModuleFn = sourceModuleFn; this }
def withModuleClass(moduleClassFn: Context => Symbol): this.type = { myModuleClassFn = moduleClassFn; this }
}
/** A subclass of LazyTypes where type parameters can be completed independently of
* the info.
*/
trait TypeParamsCompleter extends LazyType {
/** The type parameters computed by the completer before completion has finished */
def completerTypeParams(sym: Symbol)(implicit ctx: Context): List[TypeSymbol]
}
val NoSymbolFn = (ctx: Context) => NoSymbol
/** A missing completer */
@sharable class NoCompleter extends LazyType {
def complete(denot: SymDenotation)(implicit ctx: Context): Unit = unsupported("complete")
}
object NoCompleter extends NoCompleter
/** A lazy type for modules that points to the module class.
* Needed so that `moduleClass` works before completion.
* Completion of modules is always completion of the underlying
* module class, followed by copying the relevant fields to the module.
*/
class ModuleCompleter(_moduleClass: ClassSymbol) extends LazyType {
override def moduleClass(implicit ctx: Context) = _moduleClass
def complete(denot: SymDenotation)(implicit ctx: Context): Unit = {
val from = moduleClass.denot.asClass
denot.setFlag(from.flags.toTermFlags & RetainedModuleValFlags)
denot.annotations = from.annotations filter (_.appliesToModule)
// !!! ^^^ needs to be revised later. The problem is that annotations might
// only apply to the module but not to the module class. The right solution
// is to have the module class completer set the annotations of both the
// class and the module.
denot.info = moduleClass.typeRef
denot.privateWithin = from.privateWithin
}
}
/** A completer for missing references */
class StubInfo() extends LazyType {
def initializeToDefaults(denot: SymDenotation)(implicit ctx: Context) = {
denot.info = denot match {
case denot: ClassDenotation =>
ClassInfo(denot.owner.thisType, denot.classSymbol, Nil, EmptyScope)
case _ =>
ErrorType
}
denot.privateWithin = NoSymbol
}
def complete(denot: SymDenotation)(implicit ctx: Context): Unit = {
val sym = denot.symbol
val file = sym.associatedFile
val (location, src) =
if (file != null) (s" in $file", file.toString)
else ("", "the signature")
val name = ctx.fresh.setSetting(ctx.settings.debugNames, true).nameString(denot.name)
ctx.error(
s"""|bad symbolic reference. A signature$location
|refers to $name in ${denot.owner.showKind} ${denot.owner.showFullName} which is not available.
|It may be completely missing from the current classpath, or the version on
|the classpath might be incompatible with the version used when compiling $src.""".stripMargin)
if (ctx.debug) throw new Error()
initializeToDefaults(denot)
}
}
// ---- Fingerprints -----------------------------------------------------
/** A fingerprint is a bitset that acts as a bloom filter for sets
* of names.
*/
class FingerPrint(val bits: Array[Long]) extends AnyVal {
import FingerPrint._
/** Include some bits of name's hashcode in set */
def include(name: Name): Unit = {
val hash = name.hashCode & Mask
bits(hash >> WordSizeLog) |= (1L << hash)
}
/** Include all bits of `that` fingerprint in set */
def include(that: FingerPrint): Unit =
for (i <- 0 until NumWords) bits(i) |= that.bits(i)
/** Does set contain hash bits of given name? */
def contains(name: Name): Boolean = {
val hash = name.hashCode & Mask
(bits(hash >> WordSizeLog) & (1L << hash)) != 0
}
}
object FingerPrint {
def apply() = new FingerPrint(new Array[Long](NumWords))
val unknown = new FingerPrint(null)
private final val WordSizeLog = 6
private final val NumWords = 32
private final val NumBits = NumWords << WordSizeLog
private final val Mask = NumBits - 1
}
private val AccessorOrLabel = Accessor | Label
@sharable private var indent = 0 // for completions printing
}