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Reflection Library for the Scala Programming Language
/*
* Scala (https://www.scala-lang.org)
*
* Copyright EPFL and Lightbend, Inc.
*
* Licensed under Apache License 2.0
* (http://www.apache.org/licenses/LICENSE-2.0).
*
* See the NOTICE file distributed with this work for
* additional information regarding copyright ownership.
*/
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
*/
package scala
package reflect
package internal
import scala.collection.immutable
import scala.collection.mutable.ListBuffer
import util.{ ReusableInstance, Statistics, shortClassOfInstance }
import Flags._
import scala.annotation.tailrec
import scala.reflect.io.{AbstractFile, NoAbstractFile}
import Variance._
trait Symbols extends api.Symbols { self: SymbolTable =>
import definitions._
import statistics._
protected var ids = 0
def getCurrentSymbolIdCount: Int = ids
protected def nextId() = { ids += 1; ids }
/** Used to keep track of the recursion depth on locked symbols */
private[this] var _recursionTable = immutable.Map.empty[Symbol, Int]
def recursionTable = _recursionTable
def recursionTable_=(value: immutable.Map[Symbol, Int]) = _recursionTable = value
private[this] var _lockedCount = 0
def lockedCount = this._lockedCount
def lockedCount_=(i: Int) = _lockedCount = i
@deprecated("Global existential IDs no longer used", "2.12.1")
private[this] var existentialIds = 0
@deprecated("Global existential IDs no longer used", "2.12.1")
protected def nextExistentialId() = { existentialIds += 1; existentialIds }
@deprecated("Use overload that accepts an id", "2.12.1")
protected def freshExistentialName(suffix: String): TypeName = freshExistentialName(suffix, nextExistentialId())
protected def freshExistentialName(suffix: String, id: Int): TypeName = newTypeName("_" + id + suffix)
// Set the fields which point companions at one another. Returns the module.
def connectModuleToClass(m: ModuleSymbol, moduleClass: ClassSymbol): ModuleSymbol = {
moduleClass.sourceModule = m
m setModuleClass moduleClass
m
}
/** Create a new free term. Its owner is NoSymbol.
*/
def newFreeTermSymbol(name: TermName, value: => Any, flags: Long = 0L, origin: String): FreeTermSymbol =
new FreeTermSymbol(name, value, origin) initFlags flags
/** Create a new free type. Its owner is NoSymbol.
*/
def newFreeTypeSymbol(name: TypeName, flags: Long = 0L, origin: String): FreeTypeSymbol =
new FreeTypeSymbol(name, origin) initFlags flags
/**
* This map stores the original owner the first time the owner of a symbol is re-assigned.
* The original owner of a symbol is needed in some places in the backend. Ideally, owners should
* be versioned like the type history.
*/
private[this] val originalOwnerMap = perRunCaches.newAnyRefMap[Symbol, Symbol]()
// TODO - don't allow the owner to be changed without checking invariants, at least
// when under some flag. Define per-phase invariants for owner/owned relationships,
// e.g. after flatten all classes are owned by package classes, there are lots and
// lots of these to be declared (or more realistically, discovered.)
// could be private since 2.11.6, but left protected to avoid potential breakages (eg ensime)
protected def saveOriginalOwner(sym: Symbol): Unit = {
// some synthetic symbols have NoSymbol as owner initially
if (sym.owner != NoSymbol) {
if (originalOwnerMap contains sym) ()
else defineOriginalOwner(sym, sym.rawowner)
}
}
def defineOriginalOwner(sym: Symbol, owner: Symbol): Unit = {
originalOwnerMap(sym) = owner
}
def symbolOf[T: WeakTypeTag]: TypeSymbol = weakTypeOf[T].typeSymbolDirect.asType
abstract class SymbolContextApiImpl extends SymbolApi {
this: Symbol =>
def isFreeTerm: Boolean = false
def asFreeTerm: FreeTermSymbol = throw new ScalaReflectionException(s"$this is not a free term")
def isFreeType: Boolean = false
def asFreeType: FreeTypeSymbol = throw new ScalaReflectionException(s"$this is not a free type")
def isExistential: Boolean = this.isExistentiallyBound
def isParamWithDefault: Boolean = this.hasDefault
// `isByNameParam` is only true for a call-by-name parameter of a *method*,
// an argument of the primary constructor seen in the class body is excluded by `isValueParameter`
def isByNameParam: Boolean = this.isValueParameter && (this hasFlag BYNAMEPARAM)
def isImplementationArtifact: Boolean = this hasFlag (BRIDGE | VBRIDGE | ARTIFACT)
def isJava: Boolean = isJavaDefined
def isField: Boolean = isTerm && !isModule && (!isMethod || owner.isTrait && isAccessor)
def isMutableVal = if (owner.isTrait) !hasFlag(STABLE) else isMutable
def isVal: Boolean = isField && !isMutableVal
def isVar: Boolean = isField && !isLazy && isMutableVal
def isAbstract: Boolean = isAbstractClass || isDeferred || isAbstractType
def isPrivateThis = this hasAllFlags (PRIVATE | LOCAL)
def isProtectedThis = this hasAllFlags (PROTECTED | LOCAL)
def isJavaEnum: Boolean = hasJavaEnumFlag
def isJavaAnnotation: Boolean = hasJavaAnnotationFlag
def isStaticAnnotation: Boolean =
initialize.hasJavaAnnotationFlag || isNonBottomSubClass(StaticAnnotationClass) && this != NowarnClass
def newNestedSymbol(name: Name, pos: Position, newFlags: Long, isClass: Boolean): Symbol = name match {
case n: TermName => newTermSymbol(n, pos, newFlags)
case n: TypeName => if (isClass) newClassSymbol(n, pos, newFlags) else newNonClassSymbol(n, pos, newFlags)
}
def knownDirectSubclasses = {
// See `getFlag` to learn more about the `isThreadsafe` call in the body of this method.
if (!isCompilerUniverse && !isThreadsafe(purpose = AllOps)) initialize
enclosingPackage.info.decls.foreach { sym =>
if(sourceFile == sym.sourceFile) {
sym.rawInfo.forceDirectSuperclasses()
}
}
if(!isPastTyper)
updateAttachment(KnownDirectSubclassesCalled)
children
}
def selfType = {
// See `getFlag` to learn more about the `isThreadsafe` call in the body of this method.
if (!isCompilerUniverse && !isThreadsafe(purpose = AllOps)) initialize
typeOfThis
}
def baseClasses = info.baseClasses
def module = sourceModule
def thisPrefix: Type = thisType
def superPrefix(supertpe: Type): Type = SuperType(thisType, supertpe)
// These two methods used to call fullyInitializeSymbol on `this`.
//
// The only positive effect of that is, to the best of my knowledge, convenient printing
// (if you print a signature of the symbol that's not fully initialized,
// you might end up with weird 's in value/type params)
//
// Another effect is obviously full initialization of that symbol,
// but that one shouldn't be necessary from the public API standpoint,
// because everything that matters auto-initializes at runtime,
// and auto-initialization at compile-time is anyway dubious
// (I've had spurious cyclic refs caused by calling typeSignature
// that initialized parent, which was in the middle of initialization).
//
// Given that and also given the pressure of being uniform with info and infoIn,
// I've removed calls to fullyInitializeSymbol from typeSignature and typeSignatureIn,
// injected fullyInitializeSymbol in showDecl, and injected fullyInitializeType in runtime Type.toString
// (the latter will make things a bit harder to debug in runtime universe, because
// toString might now very rarely cause cyclic references, but we also have showRaw that doesn't do initialization).
//
// Auto-initialization in runtime Type.toString is one of the examples of why a cake-based design
// isn't a very good idea for reflection API. Sometimes we want to same pretty name for both a compiler-facing
// and a user-facing API that should have different behaviors (other examples here include isPackage, isCaseClass, etc).
// Within a cake it's fundamentally impossible to achieve that.
def typeSignature: Type = info
def typeSignatureIn(site: Type): Type = site memberInfo this
def toType: Type = tpe
def toTypeIn(site: Type): Type = site.memberType(this)
def toTypeConstructor: Type = typeConstructor
def setAnnotations(annots: AnnotationInfo*): this.type = { setAnnotations(annots.toList); this }
def getter: Symbol = getterIn(owner)
def setter: Symbol = setterIn(owner)
def companion: Symbol = {
if (isModule && !hasPackageFlag) companionSymbol
else if (isModuleClass && !isPackageClass) sourceModule.companionSymbol
else if (isClass && !isModuleClass && !isPackageClass) companionSymbol
else NoSymbol
}
def infoIn(site: Type): Type = typeSignatureIn(site)
def overrides: List[Symbol] = allOverriddenSymbols
def paramLists: List[List[Symbol]] = paramss
}
private[reflect] final case class SymbolKind(accurate: String, sanitized: String, abbreviation: String) {
def skolemize: SymbolKind = copy(accurate = s"$accurate skolem", abbreviation = s"$abbreviation#SKO")
}
protected def newStubSymbol(owner: Symbol,
name: Name,
missingMessage: String): Symbol = {
name match {
case n: TypeName => new StubClassSymbol(owner, n, missingMessage)
case _ => new StubTermSymbol(owner, name.toTermName, missingMessage)
}
}
/** The class for all symbols */
abstract class Symbol protected[Symbols] (initOwner: Symbol, initPos: Position, initName: Name)
extends SymbolContextApiImpl
with HasFlags
with Annotatable[Symbol]
with Attachable {
protected[this] final var _rawname = initName
// makes sure that all symbols that runtime reflection deals with are synchronized
private def isSynchronized = this.isInstanceOf[scala.reflect.runtime.SynchronizedSymbols#SynchronizedSymbol]
private def isAprioriThreadsafe = isThreadsafe(AllOps)
if (!(isCompilerUniverse || isSynchronized || isAprioriThreadsafe))
throw new AssertionError(s"unsafe symbol $initName (child of $initOwner) in runtime reflection universe") // Not an assert to avoid retention of `initOwner` as a field!
type AccessBoundaryType = Symbol
type AnnotationType = AnnotationInfo
// TODO - don't allow names to be renamed in this unstructured fashion.
// Rename as little as possible. Enforce invariants on all renames.
type TypeOfClonedSymbol >: Null <: Symbol { type NameType = Symbol.this.NameType }
final def rawname: NameType = _rawname.asInstanceOf[NameType]
final def name: NameType = if (needsFlatClasses) flattenedName else _rawname.asInstanceOf[NameType]
def name_=(n: Name): Unit = {
if (shouldLogAtThisPhase) {
def msg = s"In $owner, renaming $name -> $n"
if (isSpecialized) debuglog(msg) else log(msg)
}
}
protected[this] def flattenedName: NameType = rawname
def asNameType(n: Name): NameType
// Syncnote: need not be protected, as only assignment happens in owner_=, which is not exposed to api
// The null check is for NoSymbol, which can't pass a reference to itself to the constructor and also
// can't call owner_= due to an assertion it contains.
private[this] var _rawowner = if (initOwner eq null) this else initOwner
private[this] var _rawflags: Long = _
final def rawowner = _rawowner
final def rawflags = _rawflags
rawatt = initPos
final val id = nextId() // identity displayed when -uniqid
//assert(id != 3390, initName)
private[this] var _validTo: Period = NoPeriod
if (traceSymbolActivity)
traceSymbols.recordNewSymbol(this)
def validTo = _validTo
def validTo_=(x: Period): Unit = { _validTo = x}
def setName(name: Name): this.type = { this.name = asNameType(name) ; this }
// Update the surrounding scopes
protected[this] def changeNameInOwners(name: Name): Unit = {
if (owner.isClass) {
var ifs = owner.infos
while (ifs != null) {
ifs.info.decls.rehash(this, name)
ifs = ifs.prev
}
}
}
def rawFlagString(mask: Long): String = calculateFlagString(rawflags & mask)
def rawFlagString: String = rawFlagString(flagMask)
def debugFlagString: String = flagString(AllFlags)
/** String representation of symbol's variance */
def varianceString: String = variance.symbolicString
override def flagMask =
if (settings.isDebug && !isAbstractType) AllFlags
else if (owner.isRefinementClass) ExplicitFlags & ~OVERRIDE
else ExplicitFlags
// make the error message more googlable
def flagsExplanationString =
if (isGADTSkolem) " (this is a GADT skolem)"
else ""
def shortSymbolClass = shortClassOfInstance(this)
def symbolCreationString: String = (
"%s%25s | %-40s | %s".format(
if (settings.uniqid) "%06d | ".format(id) else "",
shortSymbolClass,
name.decode + " in " + owner,
rawFlagString
)
)
// ------ creators -------------------------------------------------------------------
final def newValue(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): TermSymbol =
newTermSymbol(name, pos, newFlags)
final def newVariable(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): TermSymbol =
newTermSymbol(name, pos, MUTABLE | newFlags)
final def newValueParameter(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): TermSymbol =
newTermSymbol(name, pos, PARAM | newFlags)
/** Create local dummy for template (owner of local blocks) */
final def newLocalDummy(pos: Position): TermSymbol =
newTermSymbol(nme.localDummyName(this), pos) setInfo NoType
final def newMethod(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): MethodSymbol =
createMethodSymbol(name, pos, METHOD | newFlags)
final def newMethodSymbol(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): MethodSymbol =
createMethodSymbol(name, pos, METHOD | newFlags)
final def newLabel(name: TermName, pos: Position = NoPosition): MethodSymbol =
newMethod(name, pos, LABEL)
/** Propagates ConstrFlags (JAVA, specifically) from owner to constructor. */
final def newConstructor(pos: Position, newFlags: Long = 0L): MethodSymbol =
newMethod(nme.CONSTRUCTOR, pos, getFlag(ConstrFlags) | newFlags)
/** Static constructor with info set. */
def newStaticConstructor(pos: Position): MethodSymbol =
newConstructor(pos, STATIC) setInfo UnitTpe
/** Instance constructor with info set. */
def newClassConstructor(pos: Position): MethodSymbol =
newConstructor(pos) setInfo MethodType(Nil, this.tpe)
def newLinkedModule(moduleClass: Symbol, newFlags: Long = 0L): ModuleSymbol = {
val m = newModuleSymbol(moduleClass.name.toTermName, moduleClass.pos, MODULE | newFlags)
connectModuleToClass(m, moduleClass.asInstanceOf[ClassSymbol])
}
final def newModule(name: TermName, pos: Position = NoPosition, newFlags0: Long = 0L): ModuleSymbol = {
val newFlags = newFlags0 | MODULE
val m = newModuleSymbol(name, pos, newFlags)
val clazz = newModuleClass(name.toTypeName, pos, newFlags & ModuleToClassFlags)
connectModuleToClass(m, clazz)
}
final def newPackage(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): ModuleSymbol = {
assert(name == nme.ROOT || isPackageClass, this)
newModule(name, pos, PackageFlags | newFlags)
}
final def newThisSym(name: TermName = nme.this_, pos: Position = NoPosition): TermSymbol =
newTermSymbol(name, pos, SYNTHETIC)
final def newImport(pos: Position): TermSymbol =
newTermSymbol(nme.IMPORT, pos)
final def newModuleSymbol(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): ModuleSymbol =
newTermSymbol(name, pos, newFlags).asInstanceOf[ModuleSymbol]
final def newModuleAndClassSymbol(name: Name, pos: Position, flags0: FlagSet): (ModuleSymbol, ClassSymbol) = {
val flags = flags0 | MODULE
val m = newModuleSymbol(name.toTermName, pos, flags)
val c = newModuleClass(name.toTypeName, pos, flags & ModuleToClassFlags)
connectModuleToClass(m, c)
(m, c)
}
final def newModuleClassSymbol(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): ModuleClassSymbol =
newClassSymbol(name, pos, newFlags).asInstanceOf[ModuleClassSymbol]
final def newTypeSkolemSymbol(name: TypeName, origin: AnyRef, pos: Position = NoPosition, newFlags: Long = 0L): TypeSkolem =
createTypeSkolemSymbol(name, origin, pos, newFlags)
/** @param pre type relative to which alternatives are seen.
* for instance:
* class C[T] {
* def m(x: T): T
* def m'(): T
* }
* val v: C[Int]
*
* Then v.m has symbol TermSymbol(flags = {OVERLOADED},
* tpe = OverloadedType(C[Int], List(m, m')))
* You recover the type of m doing a
*
* m.tpe.asSeenFrom(pre, C) (generally, owner of m, which is C here).
*
* or:
*
* pre.memberType(m)
*/
final def newOverloaded(pre: Type, alternatives: List[Symbol]): TermSymbol = {
val triedCookingFlag = if (alternatives.forall(_.hasFlag(TRIEDCOOKING))) TRIEDCOOKING else 0L
newTermSymbol(alternatives.head.name.toTermName, alternatives.head.pos, OVERLOADED | triedCookingFlag) setInfo OverloadedType(pre, alternatives)
}
final def newErrorValue(name: TermName): TermSymbol =
newTermSymbol(name, pos, SYNTHETIC | IS_ERROR) setInfo ErrorType
/** Symbol of a type definition type T = ...
*/
final def newAliasType(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): AliasTypeSymbol =
createAliasTypeSymbol(name, pos, newFlags)
/** Symbol of an abstract type type T >: ... <: ...
*/
final def newAbstractType(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): AbstractTypeSymbol =
createAbstractTypeSymbol(name, pos, DEFERRED | newFlags)
/** Symbol of a type parameter
*/
final def newTypeParameter(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): TypeSymbol =
newAbstractType(name, pos, PARAM | newFlags)
// is defined in SymbolCreations
// final def newTypeSymbol(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): TypeSymbol =
// (if ((newFlags & DEFERRED) != 0) new AbstractTypeSymbol(this, pos, name)
// else new AbstractTypeSymbol(this, pos, name)) setFlag newFlags
/** Symbol of an existential type T forSome { ... }
*/
final def newExistential(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): TypeSymbol =
newAbstractType(name, pos, EXISTENTIAL | newFlags)
private def freshNamer: () => TermName = {
var cnt = 0
() => { cnt += 1; nme.syntheticParamName(cnt) }
}
/** Synthetic value parameters when parameter symbols are not available.
* Calling this method multiple times will re-use the same parameter names.
*/
final def newSyntheticValueParams(argtypes: List[Type]): List[TermSymbol] =
newSyntheticValueParams(argtypes, freshNamer)
final def newSyntheticValueParams(argtypes: List[Type], freshName: () => TermName): List[TermSymbol] =
argtypes map (tp => newSyntheticValueParam(tp, freshName()))
/** Synthetic value parameter when parameter symbol is not available.
* Calling this method multiple times will re-use the same parameter name.
*/
final def newSyntheticValueParam(argtype: Type, name: TermName = nme.syntheticParamName(1)): TermSymbol =
newValueParameter(name, owner.pos.focus, SYNTHETIC) setInfo argtype
def newSyntheticTypeParam(name: String, newFlags: Long): TypeSymbol = newTypeParameter(newTypeName(name), NoPosition, newFlags) setInfo TypeBounds.empty
def newSyntheticTypeParams(num: Int): List[TypeSymbol] = (0 until num).toList map (n => newSyntheticTypeParam("T" + n, 0L))
/** Create a new existential type skolem with this symbol its owner,
* based on the given symbol and origin.
*/
def newExistentialSkolem(basis: Symbol, origin: AnyRef): TypeSkolem =
newExistentialSkolem(basis.name.toTypeName, basis.info, basis.flags, basis.pos, origin)
/** Create a new existential type skolem with this symbol its owner, and the given other properties.
*/
def newExistentialSkolem(name: TypeName, info: Type, flags: Long, pos: Position, origin: AnyRef): TypeSkolem = {
val skolem = newTypeSkolemSymbol(name.toTypeName, origin, pos, (flags | EXISTENTIAL) & ~PARAM)
skolem setInfo (info cloneInfo skolem)
}
// don't test directly -- use isGADTSkolem
// used to single out a gadt skolem symbol in deskolemizeGADT
// gadtskolems are created in adaptConstrPattern and removed at the end of typedCase
final protected[Symbols] def GADT_SKOLEM_FLAGS = CASEACCESSOR | SYNTHETIC
// flags set up to maintain TypeSkolem's invariant: origin.isInstanceOf[Symbol] == !hasFlag(EXISTENTIAL)
// GADT_SKOLEM_FLAGS (== CASEACCESSOR | SYNTHETIC) used to single this symbol out in deskolemizeGADT
// TODO: it would be better to allocate a new bit in the flag long for GADTSkolem rather than OR'ing together CASEACCESSOR | SYNTHETIC
def newGADTSkolem(name: TypeName, origin: Symbol, info: Type): TypeSkolem =
newTypeSkolemSymbol(name, origin, origin.pos, origin.flags & ~(EXISTENTIAL | PARAM) | GADT_SKOLEM_FLAGS) setInfo info
@deprecated("Use overload that accepts an id", "2.12.1")
final def freshExistential(suffix: String): TypeSymbol =
newExistential(freshExistentialName(suffix), pos)
final def freshExistential(suffix: String, id: Int): TypeSymbol =
newExistential(freshExistentialName(suffix, id), pos)
/** Type skolems are type parameters ''seen from the inside''
* Assuming a polymorphic method m[T], its type is a PolyType which has a TypeParameter
* with name `T` in its typeParams list. While type checking the parameters, result type and
* body of the method, there's a local copy of `T` which is a TypeSkolem.
*/
final def newTypeSkolem: TypeSkolem =
owner.newTypeSkolemSymbol(name.toTypeName, this, pos, flags)
final def newClass(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): ClassSymbol =
newClassSymbol(name, pos, newFlags)
/** A new class with its info set to a ClassInfoType with given scope and parents. */
def newClassWithInfo(name: TypeName, parents: List[Type], scope: Scope, pos: Position = NoPosition, newFlags: Long = 0L): ClassSymbol = {
val clazz = newClass(name, pos, newFlags)
clazz setInfo ClassInfoType(parents, scope, clazz)
}
final def newErrorClass(name: TypeName): ClassSymbol =
newClassWithInfo(name, Nil, new ErrorScope(this), pos, SYNTHETIC | IS_ERROR)
final def newModuleClass(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): ModuleClassSymbol =
newModuleClassSymbol(name, pos, newFlags | MODULE)
final def newAnonymousFunctionClass(pos: Position = NoPosition, newFlags: Long = 0L): ClassSymbol =
newClassSymbol(tpnme.ANON_FUN_NAME, pos, FINAL | SYNTHETIC | newFlags)
final def newAnonymousFunctionValue(pos: Position, newFlags: Long = 0L): TermSymbol =
newTermSymbol(nme.ANON_FUN_NAME, pos, SYNTHETIC | newFlags) setInfo NoType
/** Refinement types P { val x: String; type T <: Number }
* also have symbols, they are refinementClasses
*/
final def newRefinementClass(pos: Position): RefinementClassSymbol =
createRefinementClassSymbol(pos, 0L)
final def newErrorSymbol(name: Name): Symbol = name match {
case x: TypeName => newErrorClass(x)
case x: TermName => newErrorValue(x)
}
/** Creates a placeholder symbol for when a name is encountered during
* unpickling for which there is no corresponding classfile. This defers
* failure to the point when that name is used for something, which is
* often to the point of never.
*/
def newStubSymbol(name: Name, missingMessage: String): Symbol = {
// Invoke the overridden `newStubSymbol` in Global that gives us access to typer
Symbols.this.newStubSymbol(this, name, missingMessage)
}
/** Given a field, construct a term symbol that represents the source construct that gave rise the field */
def sugaredSymbolOrSelf = {
val getter = getterIn(owner)
if (getter == NoSymbol) {
this
} else {
val result = owner.newValue(getter.name.toTermName, newFlags = getter.flags & ~Flags.METHOD).setPrivateWithin(getter.privateWithin).setInfo(getter.info.resultType)
val setter = setterIn(owner)
if (setter != NoSymbol) result.setFlag(Flags.MUTABLE)
result
}
}
// ----- locking and unlocking ------------------------------------------------------
// True if the symbol is unlocked.
// True if the symbol is locked but still below the allowed recursion depth.
// False otherwise
private[scala] def lockOK: Boolean = {
((_rawflags & LOCKED) == 0L) ||
((settings.Yrecursion.value != 0) &&
(recursionTable get this match {
case Some(n) => (n <= settings.Yrecursion.value)
case None => true }))
}
// Lock a symbol, using the handler if the recursion depth becomes too great.
private[scala] def lock(handler: => Unit): Boolean = {
if ((_rawflags & LOCKED) != 0L) {
if (settings.Yrecursion.value != 0) {
recursionTable get this match {
case Some(n) =>
if (n > settings.Yrecursion.value) {
handler
false
} else {
recursionTable += (this -> (n + 1))
true
}
case None =>
recursionTable += (this -> 1)
true
}
} else { handler; false }
} else {
_rawflags |= LOCKED
true
}
}
// Unlock a symbol
private[scala] def unlock() = {
if ((_rawflags & LOCKED) != 0L) {
_rawflags &= ~LOCKED
if (settings.Yrecursion.value != 0)
recursionTable -= this
}
}
// ----- tests ----------------------------------------------------------------------
def isAliasType = false
def isAbstractType = false
def isSkolem = false
/** A Type, but not a Class. */
def isNonClassType = false
/** The bottom classes are Nothing and Null, found in Definitions. */
def isBottomClass = false
/** These are all tests for varieties of ClassSymbol, which has these subclasses:
* - ModuleClassSymbol
* - RefinementClassSymbol
* - PackageClassSymbol (extends ModuleClassSymbol)
*/
def isAbstractClass = false
def isAnonOrRefinementClass = false
def isAnonymousClass = false
def isCaseClass = false
def isConcreteClass = false
@deprecated("trait implementation classes have been removed in Scala 2.12", "2.12.0")
def isImplClass = false
def isJavaInterface = false
def isNumericValueClass = false
def isPrimitiveValueClass = false
def isRefinementClass = false
override def isTrait = false
/** Qualities of Types, always false for TermSymbols.
*/
def isContravariant = false
def isCovariant = false
def isExistentialSkolem = false
def isExistentiallyBound = false
def isGADTSkolem = false
def isTypeParameter = false
def isTypeParameterOrSkolem = false
def isTypeSkolem = false
def isInvariant = !isCovariant && !isContravariant
/** Qualities of Terms, always false for TypeSymbols.
*/
def isAccessor = false
def isBridge = false
def isCapturedVariable = false
def isClassConstructor = false
def isConstructor = false
def isEarlyInitialized = false
def isGetter = false
def isDefaultGetter = false
def isLocalDummy = false
def isMixinConstructor = false
def isOverloaded = false
def isSetter = false
def isSetterParameter = false
def isValue = false
def isValueParameter = false
def isVariable = false
def isTermMacro = false
/** Qualities of MethodSymbols, always false for TypeSymbols
* and other TermSymbols.
*/
def isCaseAccessorMethod = false
def isLiftedMethod = false
def isSourceMethod = false
def isVarargsMethod = false
override def isLabel = false
/** Package/package object tests */
def isPackageClass = false
def isPackageObject = false
def isPackageObjectClass = false
def isPackageObjectOrClass = isPackageObject || isPackageObjectClass
def isModuleOrModuleClass = isModule || isModuleClass
/** Overridden in custom objects in Definitions */
def isRoot = false
def isRootPackage = false
def isRootSymbol = false // RootPackage and RootClass. TODO: also NoSymbol.
def isEmptyPackage = false
def isEmptyPackageClass = false
/** Is this symbol an effective root for fullname string?
*/
def isEffectiveRoot = false
/** Can this symbol only be subclassed by bottom classes? This is assessed
* to be the case if it is final, and any type parameters are invariant.
*/
def hasOnlyBottomSubclasses = {
@tailrec
def loop(tparams: List[Symbol]): Boolean = tparams match {
case Nil => true
case x :: xs => x.variance.isInvariant && loop(xs)
}
isClass && isFinal && loop(typeParams)
}
final def isOverridableMember = !(isClass || isEffectivelyFinal || isTypeParameter) && safeOwner.isClass
/** Does this symbol denote a wrapper created by the repl? */
final def isInterpreterWrapper = isTopLevel && nme.isReplWrapperName(name)
/** In our current architecture, symbols for top-level classes and modules
* are created as dummies. Package symbols just call newClass(name) or newModule(name) and
* consider their job done.
*
* In order for such a dummy to provide meaningful info (e.g. a list of its members),
* it needs to go through unpickling. Unpickling is a process of reading Scala metadata
* from ScalaSignature annotations and assigning it to symbols and types.
*
* A single unpickling session takes a top-level class or module, parses the ScalaSignature annotation
* and then reads metadata for the unpicklee, its companion (if any) and all their members recursively
* (i.e. the pickle not only contains info about directly nested classes/modules, but also about
* classes/modules nested into those and so on).
*
* Unpickling is triggered automatically whenever info (info in compiler parlance) is called.
* This happens because package symbols assign completer thunks to the dummies they create.
* Therefore metadata loading happens lazily and transparently.
*
* Almost transparently. Unfortunately metadata isn't limited to just signatures (i.e. lists of members).
* It also includes flags (which determine e.g. whether a class is sealed or not), annotations and privateWithin.
* This gives rise to unpleasant effects like in scala/bug#6277, when a flag test called on an uninitialize symbol
* produces incorrect results.
*
* One might think that the solution is simple: automatically call the completer
* whenever one needs flags, annotations and privateWithin - just like it's done for info.
* Unfortunately, this leads to weird crashes in scalac, and currently we can't attempt
* to fix the core of the compiler risk stability a few weeks before the final release.
* upd. Haha, "a few weeks before the final release". This surely sounds familiar :)
*
* However we do need to fix this for runtime reflection, since this idiosyncrasy is not something
* we'd like to expose to reflection users. Therefore a proposed solution is to check whether we're in a
* runtime reflection universe, and if yes and if we've not yet loaded the requested info, then to commence initialization.
*/
def getFlag(mask: Long): Long = {
mask & (if ((mask & PhaseIndependentFlags) == mask) rawflags else flags)
}
/** Does symbol have ANY flag in `mask` set? */
final def hasFlag(mask: Long): Boolean = getFlag(mask) != 0
/** Does symbol have ALL the flags in `mask` set? */
final def hasAllFlags(mask: Long): Boolean = getFlag(mask) == mask
def setFlag(mask: Long): this.type = { _rawflags |= mask ; this }
def resetFlag(mask: Long): this.type = { _rawflags &= ~mask ; this }
def resetFlags(): Unit = { rawflags = 0 }
/** Default implementation calls the generic string function, which
* will print overloaded flags as . Subclasses
* of Symbol refine.
*/
override def resolveOverloadedFlag(flag: Long): String = Flags.flagToString(flag)
/** Set the symbol's flags to the given value, asserting
* that the previous value was 0.
*/
def initFlags(mask: Long): this.type = {
assert(rawflags == 0L, symbolCreationString)
_rawflags = mask
this
}
final def flags: Long = {
flags(phase.flagMask)
}
private[reflect] final def flags(phaseFlagMask: Long): Long = {
val fs = _rawflags & phaseFlagMask
(fs | ((fs & LateFlags) >>> LateShift)) & ~((fs & AntiFlags) >>> AntiShift)
}
def flags_=(fs: Long) = _rawflags = fs
def rawflags_=(x: Long): Unit = { _rawflags = x }
final def hasGetter = isTerm && nme.isLocalName(name)
/**
* Nested modules with a non-static owner receive the METHOD flag during UnCurry's info transform.
* (They are replaced by a ClassDef and DefDef for the module accessor during the fields phase.)
*
* Note: the METHOD flag is added lazily in the info transformer of the UnCurry phase.
* This means that forcing the `sym.info` may change the value of `sym.isMethod`. Forcing the
* info is in the responsibility of the caller. Doing it eagerly here was tried (0ccdb151f) but
* has proven to lead to bugs (scala/bug#8907).
*
* Here's an example where one can see all four of FF FT TF TT for (isStatic, isMethod) at
* various phases.
*
* trait A1 { case class Quux() }
* object A2 extends A1 { object Flax }
* // -- namer object Quux in trait A1
* // -M flatten object Quux in trait A1
* // S- flatten object Flax in object A2
* // -M posterasure object Quux in trait A1
* // -M jvm object Quux in trait A1
* // SM jvm object Quux in object A2
*
* So "isModuleNotMethod" exists not for its achievement in brevity, but to encapsulate the
* relevant condition.
*/
def isModuleNotMethod = isModule && !isMethod
// After RefChecks, the `isStatic` check is mostly redundant: all non-static modules should
// be methods (and vice versa). There's a corner case on the vice-versa with mixed-in module
// symbols:
// trait T { object A }
// object O extends T
// The module symbol A is cloned into T$impl (addInterfaces), and then cloned into O (mixin).
// Since the original A is not static, it's turned into a method. The clone in O however is
// static (owned by a module), but it's also a method.
def isStaticModule = isModuleNotMethod && isStatic
final def isInitializedToDefault = !isType && hasAllFlags(DEFAULTINIT | ACCESSOR)
final def isThisSym = isTerm && owner.thisSym == this
final def isError = hasFlag(IS_ERROR)
final def isErroneous = isError || isInitialized && tpe_*.isErroneous
def isHigherOrderTypeParameter = owner.isTypeParameterOrSkolem
// class C extends D( { class E { ... } ... } ). Here, E is a class local to a constructor
def isClassLocalToConstructor = false
final def isDerivedValueClass =
isClass && !hasFlag(PACKAGE | TRAIT) &&
!phase.erasedTypes && info.firstParent.typeSymbol == AnyValClass && !isPrimitiveValueClass
final def isMethodWithExtension =
isMethod && owner.isDerivedValueClass && !isParamAccessor && !isConstructor && !hasFlag(SUPERACCESSOR) && !isMacro && !isSpecialized
final def isAnonymousFunction = isSynthetic && (name containsName tpnme.ANON_FUN_NAME)
final def isDelambdafyFunction = isSynthetic && (name containsName tpnme.DELAMBDAFY_LAMBDA_CLASS_NAME)
final def isDelambdafyTarget = isArtifact && isMethod && hasAttachment[DelambdafyTarget.type]
final def isDefinedInPackage = effectiveOwner.isPackageClass
final def needsFlatClasses = phase.flatClasses && (rawowner ne NoSymbol) && !rawowner.isPackageClass && !isMethod
// TODO introduce a flag for these?
final def isPatternTypeVariable: Boolean =
isAbstractType && !isExistential && !isTypeParameterOrSkolem && isLocalToBlock
/** change name by appending $$
* Do the same for any accessed symbols to preserve serialization compatibility.
* Implementation in TermSymbol.
*/
def expandName(base: Symbol): Unit = ()
// In java.lang, Predef, or scala package/package object
def isInDefaultNamespace = UnqualifiedOwners(effectiveOwner)
/** The owner, skipping package objects.
*/
def effectiveOwner = owner.skipPackageObject
/** If this is a package object or its implementing class, its owner: otherwise this.
*/
def skipPackageObject: Symbol = this
/** The package object symbol corresponding to this package or package class symbol, or NoSymbol otherwise */
@tailrec
final def packageObject: Symbol =
if (isPackageClass) tpe.packageObject
else if (hasPackageFlag) moduleClass.packageObject
else NoSymbol
/** If this is a constructor, its owner: otherwise this.
*/
final def skipConstructor: Symbol = if (isConstructor) owner else this
/** Conditions where we omit the prefix when printing a symbol, to avoid
* unpleasantries like Predef.String, $read.$iw.Foo and .Bippy.
*/
final def isOmittablePrefix = /*!settings.debug.value &&*/ {
// scala/bug#5941 runtime reflection can have distinct symbols representing `package scala` (from different mirrors)
// We check equality by FQN here to make sure we omit prefixes uniformly for all of them.
def matches(sym1: Symbol, sym2: Symbol) = (sym1 eq sym2) || (sym1.hasPackageFlag && sym2.hasPackageFlag && sym1.name == sym2.name && sym1.fullNameString == sym2.fullNameString)
val skipped = skipPackageObject
UnqualifiedOwners.exists((sym: Symbol) => matches(sym, skipped)) || isEmptyPrefix
}
def isEmptyPrefix = (
isEffectiveRoot // has no prefix for real, or
|| isAnonOrRefinementClass // has uninteresting or prefix
|| nme.isReplWrapperName(name) // $read.$iw.Foo or $read.INSTANCE.$iw.Foo
)
def isFBounded = info match {
case TypeBounds(_, _) => info.baseTypeSeq exists (_ contains this)
case _ => false
}
/** Is symbol a monomorphic type?
* assumption: if a type starts out as monomorphic, it will not acquire
* type parameters in later phases.
*/
final def isMonomorphicType =
isType && {
val info = originalInfo
( (info eq null)
|| (info.isComplete && !info.isHigherKinded)
)
}
@tailrec
final def isStrictFP: Boolean = this != NoSymbol && !isDeferred && (hasAnnotation(ScalaStrictFPAttr) || originalOwner.isStrictFP)
def isSerializable = info.baseClasses.exists(_ == SerializableClass)
def isDeprecated = hasAnnotation(DeprecatedAttr) || (isJava && hasAnnotation(JavaDeprecatedAttr))
def deprecationMessage = getAnnotation(DeprecatedAttr) flatMap (_ stringArg 0)
def deprecationVersion = getAnnotation(DeprecatedAttr) flatMap (_ stringArg 1)
def deprecatedParamName = getAnnotation(DeprecatedNameAttr) flatMap (ann => ann.symbolArg(0).orElse(ann.stringArg(0).map(newTermName)).orElse(Some(nme.NO_NAME)))
def deprecatedParamVersion = getAnnotation(DeprecatedNameAttr) flatMap (_ stringArg 1)
def hasDeprecatedInheritanceAnnotation
= hasAnnotation(DeprecatedInheritanceAttr)
def deprecatedInheritanceMessage
= getAnnotation(DeprecatedInheritanceAttr) flatMap (_ stringArg 0)
def deprecatedInheritanceVersion
= getAnnotation(DeprecatedInheritanceAttr) flatMap (_ stringArg 1)
def hasDeprecatedOverridingAnnotation
= hasAnnotation(DeprecatedOverridingAttr)
def deprecatedOverridingMessage
= getAnnotation(DeprecatedOverridingAttr) flatMap (_ stringArg 0)
def deprecatedOverridingVersion
= getAnnotation(DeprecatedOverridingAttr) flatMap (_ stringArg 1)
// !!! when annotation arguments are not literal strings, but any sort of
// assembly of strings, there is a fair chance they will turn up here not as
// Literal(const) but some arbitrary AST. However nothing in the compiler
// prevents someone from writing a @migration annotation with a calculated
// string. So this needs attention. For now the fact that migration is
// private[scala] ought to provide enough protection.
def hasMigrationAnnotation = hasAnnotation(MigrationAnnotationClass)
def migrationMessage = getAnnotation(MigrationAnnotationClass) flatMap { _.stringArg(0) }
def migrationVersion = getAnnotation(MigrationAnnotationClass) flatMap { _.stringArg(1) }
def elisionLevel = getAnnotation(ElidableMethodClass) flatMap { _.intArg(0) }
def implicitNotFoundMsg = getAnnotation(ImplicitNotFoundClass).flatMap(_.stringArg(0))
def implicitAmbiguousMsg = getAnnotation(ImplicitAmbiguousClass) flatMap { _.stringArg(0) }
def isCompileTimeOnly = hasAnnotation(CompileTimeOnlyAttr)
def compileTimeOnlyMessage = getAnnotation(CompileTimeOnlyAttr) flatMap (_ stringArg 0)
/** Is this symbol an accessor method for outer? */
final def isOuterAccessor = hasFlag(STABLE | ARTIFACT) && (unexpandedName == nme.OUTER)
/** Is this symbol an accessor method for outer? */
final def isOuterField = isArtifact && (unexpandedName == nme.OUTER_LOCAL)
/** Is this symbol an outer parameter in a constructor */
final def isOuterParam = isParameter && owner.isConstructor && (name == nme.OUTER_ARG || name == nme.OUTER)
/** Does this symbol denote a stable value, ignoring volatility?
*
* Stability and volatility are checked separately to allow volatile paths in patterns that amount to equality checks. scala/bug#6815
*/
final def isStable = isTerm && !isMutable && !(hasFlag(BYNAMEPARAM)) && (!isMethod || hasStableFlag)
final def hasVolatileType = tpe.isVolatile && !hasAnnotation(uncheckedStableClass)
/** Does this symbol denote the primary constructor of its enclosing class? */
final def isPrimaryConstructor =
isConstructor && owner.primaryConstructor == this
/** Does this symbol denote an auxiliary constructor of its enclosing class? */
final def isAuxiliaryConstructor =
isConstructor && !isPrimaryConstructor
/** Is this symbol a synthetic apply or unapply method in a companion object of a case class? */
// xeno-by: why this obscure use of the CASE flag? why not simply compare name with nme.apply and nme.unapply?
// dnw: "fixed in Dotty"? In Scala 3 unapply methods don't use the CASE flag.
final def isCaseApplyOrUnapply =
isMethod && isCase && isSynthetic
/** Is this symbol a synthetic copy method in a case class? */
final def isCaseCopy =
isMethod && owner.isCase && isSynthetic && name == nme.copy
final def isModuleVar = hasFlag(MODULEVAR)
final def isScala3Defined = hasFlag(SCALA3X)
/**
* Is this symbol static (i.e. with no outer instance)?
* Q: When exactly is a sym marked as STATIC?
* A: If it's a member of a toplevel object, or of an object contained in a toplevel object, or
* any number of levels deep.
* https://groups.google.com/group/scala-internals/browse_thread/thread/d385bcd60b08faf6
*
* TODO: should this only be invoked on class / module symbols? because there's also `isStaticMember`.
*
* Note: the result of `isStatic` changes over time.
* - Lambdalift local definitions to the class level, the `owner` field is modified.
* object T { def foo { object O } }
* After lambdalift, the OModule.isStatic is true.
*
* - After flatten, nested classes are moved to the package level. Invoking `owner` on a
* class returns a package class, for which `isStaticOwner` is true. For example,
* class C { object O }
* OModuleClass.isStatic is true after flatten. Using phase travel to get before flatten,
* method `owner` returns the class C.
*
* Why not make a stable version of `isStatic`? Maybe some parts of the compiler depend on the
* current implementation.
*/
def isStatic = (this hasFlag STATIC) || owner.isStaticOwner
/** Is this symbol a static constructor? */
final def isStaticConstructor: Boolean =
isStaticMember && isClassConstructor
/** Is this symbol a static member of its class? (i.e. needs to be implemented as a Java static?) */
final def isStaticMember: Boolean =
hasFlag(STATIC)
/** Does this symbol denote a class that defines static symbols? */
final def isStaticOwner: Boolean =
isPackageClass || isModuleClass && isStatic
/** A helper function for isEffectivelyFinal. */
private def isNotOverridden = (
owner.isClass && (
owner.isEffectivelyFinal
|| (owner.isSealed && owner.sealedChildren.forall(c => c.isEffectivelyFinal && (overridingSymbol(c) == NoSymbol)))
)
)
/** Is this symbol effectively final? I.e, it cannot be overridden */
final def isEffectivelyFinal: Boolean = (
((this hasFlag FINAL | PACKAGE) && this != SingletonClass)
|| isModuleOrModuleClass
|| isTerm && (isPrivate || isLocalToBlock || (hasAllFlags(notPRIVATE | METHOD) && !hasFlag(DEFERRED)))
// We track known subclasses of term-owned classes, use that to infer finality.
// However, don't look at owner for refinement classes (it's basically arbitrary).
|| isClass && !isRefinementClass && originalOwner.isTerm && children.isEmpty
)
/** Is this symbol effectively final or a concrete term member of sealed class whose children do not override it */
final def isEffectivelyFinalOrNotOverridden: Boolean = isEffectivelyFinal || (isTerm && !isDeferred && isNotOverridden)
/** Is this symbol owned by a package? */
final def isTopLevel = owner.isPackageClass
// shim for sbt's compiler interface
/** Is this symbol defined in a block? */
@deprecated("use isLocalToBlock instead", "2.11.0")
final def isLocal: Boolean = owner.isTerm
/** Is this symbol defined in a block? */
final def isLocalToBlock: Boolean = owner.isTerm
/** Is this symbol a constant? */
final def isConstant: Boolean = isStable && isConstantType(tpe.resultType)
/** Is this class nested in another class or module (not a package). Includes locally defined classes. */
def isNestedClass = false
/** Is this class locally defined?
* A class is local, if
* - it is anonymous, or
* - its owner is a value
* - it is defined within a local class
*/
def isLocalClass = false
/** Is this class or type defined as a structural refinement type?
*/
final def isStructuralRefinement: Boolean =
(isClass || isType || isModule) && info.dealiasWiden/*.underlying*/.isStructuralRefinement
/** Is this a term symbol only defined in a refinement (so that it needs
* to be accessed by reflection)?
*/
def isOnlyRefinementMember = (
isTerm // Type members are unaffected
&& owner.isRefinementClass // owner must be a refinement class
&& isPossibleInRefinement // any overridden symbols must also have refinement class owners
&& !isConstant // Must not be a constant. Question: Can we exclude @inline methods as well?
&& isDeclaredByOwner // Must be explicitly declared in the refinement (not synthesized from glb)
)
// "(owner.info decl name) == this" is inadequate, because "name" might
// be overloaded in owner - and this might be an overloaded symbol.
// TODO - make this cheaper and see where else we should be doing something similar.
private def isDeclaredByOwner = (owner.info decl name).alternatives exists (alternatives contains _)
final def isStructuralRefinementMember = owner.isStructuralRefinement && isPossibleInRefinement && isPublic
final def isPossibleInRefinement = (
!isConstructor
&& allOverriddenSymbols.forall(_.owner.isRefinementClass) // this includes allOverriddenSymbols.isEmpty
)
/** A 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.
*/
@tailrec
final def isIncompleteIn(base: Symbol): Boolean =
this.isDeferred ||
(this hasFlag ABSOVERRIDE) && {
val supersym = superSymbolIn(base)
supersym == NoSymbol || supersym.isIncompleteIn(base)
}
def exists: Boolean = !isTopLevel || {
val isSourceLoader = rawInfo match {
case sl: SymLoader => sl.fromSource
case _ => false
}
def warnIfSourceLoader(): Unit = {
if (isSourceLoader)
// Predef is completed early due to its autoimport; we used to get here when type checking its
// parent LowPriorityImplicits. See comment in c5441dc for more elaboration.
// Since the fix for scala/bug#7335 Predef parents must be defined in Predef.scala, and we should not
// get here anymore.
devWarning(s"calling Symbol#exists with sourcefile based symbol loader may give incorrect results.")
}
rawInfo load this
rawInfo != NoType || { warnIfSourceLoader(); false }
}
final def isInitialized: Boolean =
validTo != NoPeriod
/** We consider a symbol to be thread-safe, when multiple concurrent threads can call its methods
* (either directly or indirectly via public reflection or internal compiler infrastructure),
* without any locking and everything works as it should work.
*
* In its basic form, `isThreadsafe` always returns false. Runtime reflection augments reflection infrastructure
* with threadsafety-tracking mechanism implemented in `SynchronizedSymbol` that communicates with underlying completers
* and can sometimes return true if the symbol has been completed to the point of thread safety.
*
* The `purpose` parameter signifies whether we want to just check immutability of certain flags for the given mask.
* This is necessary to enable robust auto-initialization of `Symbol.flags` for runtime reflection, and is also quite handy
* in avoiding unnecessary initializations when requesting for flags that have already been set.
*/
def isThreadsafe(purpose: SymbolOps): Boolean = false
def markFlagsCompleted(mask: Long): this.type = this
def markAllCompleted(): this.type = this
/** Can this symbol be loaded by a reflective mirror?
*
* Scalac relies on `ScalaSignature` annotation to retain symbols across compilation runs.
* Such annotations (also called "pickles") are applied on top-level classes and include information
* about all symbols reachable from the annotee. However, local symbols (e.g. classes or definitions local to a block)
* are typically unreachable and information about them gets lost.
*
* This method is useful for macro writers who wish to save certain ASTs to be used at runtime.
* With `isLocatable` it's possible to check whether a tree can be retained as is, or it needs special treatment.
*/
final def isLocatable: Boolean = {
if (this == NoSymbol) return false
if (isRoot || isRootPackage) return true
if (!owner.isLocatable) return false
if (owner.isTerm) return false
if (isLocalDummy) return false
if (isAliasType) return true
if (isType && isNonClassType) return false
if (isRefinementClass) return false
true
}
/** The variance of this symbol. */
def variance: Variance =
if (isCovariant) Covariant
else if (isContravariant) Contravariant
else Invariant
/** The sequence number of this parameter symbol among all type
* and value parameters of symbol's owner. -1 if symbol does not
* appear among the parameters of its owner.
*/
def paramPos: Int = {
def searchIn(tpe: Type, base: Int): Int = {
def searchList(params: List[Symbol], fallback: Type): Int = {
val idx = params indexOf this
if (idx >= 0) idx + base
else searchIn(fallback, base + params.length)
}
tpe match {
case PolyType(tparams, res) => searchList(tparams, res)
case MethodType(params, res) => searchList(params, res)
case _ => -1
}
}
searchIn(owner.info, 0)
}
// ------ owner attribute --------------------------------------------------------------
/**
* The owner of a symbol. Changes over time to adapt to the structure of the trees:
* - Up to lambdalift, the owner is the lexically enclosing definition. For definitions
* in a local block, the owner is also the next enclosing definition.
* - After lambdalift, all local method and class definitions (those not owned by a class
* or package class) change their owner to the enclosing class. This is done through
* a destructive "sym.owner = sym.owner.enclClass". The old owner is saved by
* saveOriginalOwner.
* - After flatten, all classes are owned by a PackageClass. This is done through a
* phase check (if after flatten) in the (overridden) method "def owner" in
* ModuleSymbol / ClassSymbol. The `rawowner` field is not modified.
* - Owners are also changed in other situations, for example when moving trees into a new
* lexical context, e.g. in the named/default arguments transformation, or when translating
* extension method definitions.
*
* In general when seeking the owner of a symbol, one should call `owner`.
* The other possibilities include:
* - call `safeOwner` if it is expected that the target may be NoSymbol
* - call `assertOwner` if it is an unrecoverable error if the target is NoSymbol
*
* `owner` behaves like `safeOwner`, but logs NoSymbol.owner calls under -Xdev.
* `assertOwner` aborts compilation immediately if called on NoSymbol.
*/
def owner: Symbol = {
rawowner
}
final def safeOwner: Symbol = if (this eq NoSymbol) NoSymbol else owner
final def assertOwner: Symbol = if (this eq NoSymbol) abort("no-symbol does not have an owner") else owner
/**
* The initial owner of this symbol.
*/
def originalOwner: Symbol = originalOwnerMap.getOrElse(this, rawowner)
// TODO - don't allow the owner to be changed without checking invariants, at least
// when under some flag. Define per-phase invariants for owner/owned relationships,
// e.g. after flatten all classes are owned by package classes, there are lots and
// lots of these to be declared (or more realistically, discovered.)
def owner_=(owner: Symbol): Unit = {
saveOriginalOwner(this)
assert(isCompilerUniverse, "owner_= is not thread-safe; cannot be run in reflexive code")
if (traceSymbolActivity)
traceSymbols.recordNewSymbolOwner(this, owner)
_rawowner = owner
}
def ownerChain: List[Symbol] = this :: owner.ownerChain
// Non-classes skip self and return rest of owner chain; overridden in ClassSymbol.
def enclClassChain: List[Symbol] = owner.enclClassChain
def ownersIterator: Iterator[Symbol] = new collection.AbstractIterator[Symbol] {
private[this] var current = Symbol.this
def hasNext = current ne NoSymbol
def next() = { val r = current; current = current.owner; r }
}
/** Same as `ownerChain contains sym` but more efficient, and
* with a twist for refinement classes (see RefinementClassSymbol.)
*/
def hasTransOwner(sym: Symbol): Boolean = {
var o = this
while ((o ne sym) && (o ne NoSymbol)) o = o.owner
(o eq sym)
}
// ------ name attribute --------------------------------------------------------------
@deprecated("use unexpandedName", "2.11.0") def originalName: Name = unexpandedName
/** If this symbol has an expanded name, its original (unexpanded) name,
* otherwise the name itself.
*/
def unexpandedName: Name = nme.unexpandedName(name)
/** The name of the symbol before decoding, e.g. `\$eq\$eq` instead of `==`.
*/
def encodedName: String = name.toString
/** The decoded name of the symbol, e.g. `==` instead of `\$eq\$eq`.
*/
def decodedName: String = name.decode
private def addModuleSuffix(n: Name): Name =
if (needsModuleSuffix) n append nme.MODULE_SUFFIX_STRING else n
def moduleSuffix: String = (
if (needsModuleSuffix) nme.MODULE_SUFFIX_STRING
else ""
)
/** Whether this symbol needs nme.MODULE_SUFFIX_STRING (aka $) appended on the java platform.
*/
def needsModuleSuffix = (
hasModuleFlag
&& !isMethod
&& !isJavaDefined
)
/** These should be moved somewhere like JavaPlatform.
*/
def javaSimpleName: Name = addModuleSuffix(simpleName.dropLocal)
def javaBinaryName: Name = name.newName(javaBinaryNameString)
def javaBinaryNameString: String = {
if (javaBinaryNameStringCache == null)
javaBinaryNameStringCache = fullName('/', moduleSuffix)
javaBinaryNameStringCache
}
private[this] var javaBinaryNameStringCache: String = null
def javaClassName: String = fullName('.', moduleSuffix)
/** The encoded full path name of this symbol, where outer names and inner names
* are separated by `separator` characters.
* Never translates expansions of operators back to operator symbol.
* Never adds id.
* Drops package objects.
*/
final def fullName(separator: Char): String = fullName(separator, "")
private def fullName(separator: Char, suffix: CharSequence): String = {
var b: java.lang.StringBuffer = null
def loop(size: Int, sym: Symbol): Unit = {
val symName = sym.name
val nSize = symName.length - (if (symName.endsWith(nme.LOCAL_SUFFIX_STRING)) 1 else 0)
if (sym.isRoot || sym.isRootPackage || sym == NoSymbol || sym.owner.isEffectiveRoot) {
val capacity = size + nSize
b = new java.lang.StringBuffer(capacity)
symName.appendTo(b, 0, nSize)
} else {
loop(size + nSize + 1, sym.effectiveOwner.enclClass)
b.append(separator)
symName.appendTo(b, 0, nSize)
}
}
loop(suffix.length(), this)
b.append(suffix)
b.toString
}
def fullNameAsName(separator: Char): Name = name.newName(fullName(separator, ""))
/** The encoded full path name of this symbol, where outer names and inner names
* are separated by periods.
*/
final def fullName: String = fullName('.')
/**
* Symbol creation implementations.
*/
protected def createAbstractTypeSymbol(name: TypeName, pos: Position, newFlags: Long): AbstractTypeSymbol =
new AbstractTypeSymbol(this, pos, name) initFlags newFlags
protected def createAliasTypeSymbol(name: TypeName, pos: Position, newFlags: Long): AliasTypeSymbol =
new AliasTypeSymbol(this, pos, name) initFlags newFlags
protected def createTypeSkolemSymbol(name: TypeName, origin: AnyRef, pos: Position, newFlags: Long): TypeSkolem =
new TypeSkolem(this, pos, name, origin) initFlags newFlags
protected def createClassSymbol(name: TypeName, pos: Position, newFlags: Long): ClassSymbol =
new ClassSymbol(this, pos, name) initFlags newFlags
protected def createModuleClassSymbol(name: TypeName, pos: Position, newFlags: Long): ModuleClassSymbol =
new ModuleClassSymbol(this, pos, name) initFlags newFlags
protected def createPackageClassSymbol(name: TypeName, pos: Position, newFlags: Long): PackageClassSymbol =
new PackageClassSymbol(this, pos, name) initFlags newFlags
protected def createRefinementClassSymbol(pos: Position, newFlags: Long): RefinementClassSymbol =
new RefinementClassSymbol(this, pos) initFlags newFlags
protected def createPackageObjectClassSymbol(pos: Position, newFlags: Long): PackageObjectClassSymbol =
new PackageObjectClassSymbol(this, pos) initFlags newFlags
protected def createMethodSymbol(name: TermName, pos: Position, newFlags: Long): MethodSymbol =
new MethodSymbol(this, pos, name) initFlags newFlags
protected def createModuleSymbol(name: TermName, pos: Position, newFlags: Long): ModuleSymbol =
new ModuleSymbol(this, pos, name) initFlags newFlags
protected def createPackageSymbol(name: TermName, pos: Position, newFlags: Long): ModuleSymbol =
new ModuleSymbol(this, pos, name) initFlags newFlags
protected def createValueParameterSymbol(name: TermName, pos: Position, newFlags: Long): TermSymbol =
new TermSymbol(this, pos, name) initFlags newFlags
protected def createValueMemberSymbol(name: TermName, pos: Position, newFlags: Long): TermSymbol =
new TermSymbol(this, pos, name) initFlags newFlags
final def newExtensionMethodSymbol(companion: Symbol, pos: Position): MethodSymbol = {
val extensionMeth = (
companion.moduleClass.newMethod(this.name.extensionName, pos, this.flags & ~OVERRIDE & ~PROTECTED & ~PRIVATE & ~LOCAL | FINAL)
setAnnotations this.annotations
)
defineOriginalOwner(extensionMeth, this.owner)
// @strictfp on class means strictfp on all methods, but `setAnnotations` won't copy it
if (this.isStrictFP && !extensionMeth.hasAnnotation(ScalaStrictFPAttr))
extensionMeth.addAnnotation(ScalaStrictFPAttr)
this.removeAnnotation(TailrecClass) // it's on the extension method, now.
companion.info.decls.enter(extensionMeth)
}
final def newTermSymbol(name: TermName, pos: Position = NoPosition, newFlags: Long = 0L): TermSymbol = {
// Package before Module, Module before Method, or we might grab the wrong guy.
if ((newFlags & PACKAGE) != 0)
createPackageSymbol(name, pos, newFlags | PackageFlags)
else if ((newFlags & MODULE) != 0)
createModuleSymbol(name, pos, newFlags)
else if ((newFlags & METHOD) != 0)
createMethodSymbol(name, pos, newFlags)
else if ((newFlags & PARAM) != 0)
createValueParameterSymbol(name, pos, newFlags)
else
createValueMemberSymbol(name, pos, newFlags)
}
final def newClassSymbol(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): ClassSymbol = {
if (name == tpnme.REFINE_CLASS_NAME)
createRefinementClassSymbol(pos, newFlags)
else if ((newFlags & PACKAGE) != 0)
createPackageClassSymbol(name, pos, newFlags | PackageFlags)
else if (name == tpnme.PACKAGE)
createPackageObjectClassSymbol(pos, newFlags)
else if ((newFlags & MODULE) != 0)
createModuleClassSymbol(name, pos, newFlags)
else
createClassSymbol(name, pos, newFlags)
}
final def newNonClassSymbol(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): TypeSymbol = {
if ((newFlags & DEFERRED) != 0)
createAbstractTypeSymbol(name, pos, newFlags)
else
createAliasTypeSymbol(name, pos, newFlags)
}
def newTypeSymbol(name: TypeName, pos: Position = NoPosition, newFlags: Long = 0L): TypeSymbol =
newNonClassSymbol(name, pos, newFlags)
/**
* The class or term up to which this symbol is accessible, or else
* `enclosingRootClass` if it is public.
*/
def accessBoundary(base: Symbol): Symbol = {
if (hasFlag(PRIVATE) || isLocalToBlock) owner
else if (hasAccessBoundary && !phase.erasedTypes) privateWithin // Phase check needed? See comment in Context.isAccessible.
else if (hasFlag(PROTECTED)) base
else enclosingRootClass
}
def isLessAccessibleThan(other: Symbol): Boolean = {
val tb = this.accessBoundary(owner)
val ob1 = other.accessBoundary(owner)
val ob2 = ob1.linkedClassOfClass
var o = tb
while (o != NoSymbol && o != ob1 && o != ob2) {
o = o.owner
}
o != NoSymbol && o != tb
}
/** See comment in HasFlags for how privateWithin combines with flags.
*/
private[this] var _privateWithin: Symbol = _
def privateWithin = {
_privateWithin
}
def privateWithin_=(sym: Symbol): Unit = { _privateWithin = sym }
def setPrivateWithin(sym: Symbol): this.type = { privateWithin_=(sym) ; this }
/** Does symbol have a private or protected qualifier set? */
final def hasAccessBoundary = {
val pw = privateWithin
(pw ne null) && (pw ne NoSymbol)
}
// ------ info and type -------------------------------------------------------------------
private[Symbols] var infos: TypeHistory = null
def originalInfo = {
if (infos eq null) null
else {
var is = infos
while (is.prev ne null) { is = is.prev }
is.info
}
}
/** The "type" of this symbol. The type of a term symbol is its usual
* type. A TypeSymbol is more complicated; see that class for elaboration.
* Since tpe forwards to tpe_*, if you call it on a type symbol with unapplied
* type parameters, the type returned will contain dummies types. These will
* hide legitimate errors or create spurious ones if used as normal types.
*
* For type symbols, `tpe` is different than `info`. `tpe` returns a typeRef
* to the type symbol, `info` returns the type information of the type symbol,
* e.g. a ClassInfoType for classes or a TypeBounds for abstract types.
*/
final def tpe: Type = tpe_*
/** typeConstructor throws an exception when called on term
* symbols; this is a more forgiving alternative. Calls
* typeConstructor on TypeSymbols, returns info otherwise.
*/
def tpeHK: Type = info
/** Only applicable to TypeSymbols, it is the type corresponding
* to the symbol itself. For instance, the type of a List might
* be List[Int] - the same symbol's typeConstructor is simply List.
* One might be tempted to write that as List[_], and in some
* contexts this is possible, but it is discouraged because it is
* syntactically indistinguishable from and easily confused with the
* type List[T] forSome { type T; }, which can also be written List[_].
*/
def typeConstructor: Type = (
// Avoiding a third override in NoSymbol to preserve bimorphism
if (this eq NoSymbol)
abort("no-symbol does not have a type constructor (this may indicate scalac cannot find fundamental classes)")
else
abort("typeConstructor inapplicable for " + this)
)
/** The type of this symbol, guaranteed to be of kind *.
* If there are unapplied type parameters, they will be
* substituted with dummy type arguments derived from the
* type parameters. Such types are not valid in a general
* sense and will cause difficult-to-find bugs if allowed
* to roam free.
*
* If you call tpe_* explicitly to obtain these types,
* you are responsible for them as if it they were your own
* minor children.
*/
def tpe_* : Type = info
// Alternate implementation of def tpe for warning about misuse,
// disabled to keep the method maximally hotspot-friendly:
// def tpe: Type = {
// val result = tpe_*
// if (settings.debug.value && result.typeArgs.nonEmpty)
// printCaller(s"""Call to ${this.tpe} created $result: call tpe_* or tpeHK""")("")
// result
// }
/** Get type info associated with symbol at current phase, after
* ensuring that symbol is initialized (i.e. type is completed).
*/
def info: Type = {
var cnt = 0
while (_validTo == NoPeriod) {
completeInfo()
cnt += 1
// allow for two completions:
// one: sourceCompleter to LazyType, two: LazyType to completed type
def abortNoProgress() = abort(s"no progress in completing $this: ${infos.info}")
if (cnt == 3) abortNoProgress()
}
rawInfo
}
private def completeInfo(): Unit = try {
assert(infos ne null, this.name)
assert(infos.prev eq null, this.name)
val tp = infos.info
if ((_rawflags & LOCKED) != 0L) { // rolled out once for performance
lock {
setInfo(ErrorType)
throw CyclicReference(this, tp)
}
} else {
_rawflags |= LOCKED
}
val current = phase
if (isCompilerUniverse) {
try {
assertCorrectThread()
phase = phaseOf(infos.validFrom)
tp.complete(this)
} finally {
unlock()
phase = current
}
} else {
// In runtime reflection, there is only on phase, so don't mutate Global.phase which would lead to warnings
// of data races from when using TSAN to assess thread safety.
try {
tp.complete(this)
} finally {
unlock()
}
}
} catch {
case ex: CyclicReference =>
devWarning("... hit cycle trying to complete " + this.fullLocationString)
throw ex
}
def info_=(info: Type): Unit = {
assert(info ne null, "Can't assign a null type")
if (infos ne null) {
infos.reset(currentPeriod, info)
} else
infos = TypeHistory(currentPeriod, info, null)
unlock()
_validTo = if (info.isComplete) currentPeriod else NoPeriod
}
/** Set initial info. */
def setInfo(info: Type): this.type = { info_=(info); this }
/** Modifies this symbol's info in place. */
def modifyInfo(f: Type => Type): this.type = setInfo(f(info))
/** Substitute second list of symbols for first in current info.
*
* NOTE: this discards the type history (uses setInfo)
*/
def substInfo(syms0: List[Symbol], syms1: List[Symbol]): this.type =
if (syms0.isEmpty) this
else modifyInfo(_.substSym(syms0, syms1))
def setInfoOwnerAdjusted(info: Type): this.type = setInfo(info atOwner this)
/** Set the info and enter this symbol into the owner's scope. */
def setInfoAndEnter(info: Type): this.type = {
setInfo(info)
owner.info.decls enter this
this
}
/** Set new info valid from start of this phase. */
def updateInfo(info: Type): Symbol = {
val pid = phaseId(infos.validFrom)
assert(pid <= phase.id, (pid, phase.id))
if (pid == phase.id) infos = infos.prev
infos = TypeHistory(currentPeriod, info, infos)
_validTo = if (info.isComplete) currentPeriod else NoPeriod
this
}
def hasRawInfo: Boolean = infos ne null
def hasCompleteInfo = hasRawInfo && rawInfo.isComplete
// does not run adaptToNewRun, which is prone to trigger cycles (scala/bug#8029)
// TODO: give this a better name if you understand the intent of the caller.
// Is it something to do with `reallyExists` or `isStale`?
final def rawInfoIsNoType: Boolean = {
hasRawInfo && (infos.info eq NoType)
}
/** Return info without checking for initialization or completing */
def rawInfo: Type = {
// OPT: hoisting the outer reference reduces the bytecode size of this method a little which makes it more
// likely to inline into hot callers of .info
val outer = Symbols.this
var infos = this.infos
outer.assert(infos != null, "infos must not be null")
if (_validTo != NoPeriod) {
val curPeriod = outer.currentPeriod
val curPid = outer.phaseId(curPeriod)
// skip any infos that concern later phases
while (curPid < outer.phaseId(infos.validFrom) && infos.prev != null)
infos = infos.prev
if (_validTo < curPeriod) {
// adapt any infos that come from previous runs
val curPhase = outer.phase
try {
if (infos != null && outer.runId(infos.validFrom) != outer.currentRunId) {
// scala/bug#8871 Discard all but the first element of type history. Specialization only works in the resident
// compiler / REPL if re-run its info transformer in this run to correctly populate its
// per-run caches, e.g. typeEnv
adaptInfo(infos.oldest)
infos = this.infos
}
//assert(runId(validTo) == currentRunId, name)
//assert(runId(infos.validFrom) == currentRunId, name)
if (_validTo < curPeriod) {
infos = transformInfos(infos, curPhase, curPeriod)
}
} finally {
outer.phase = curPhase
}
}
}
infos.info
}
private def transformInfos(infos0: TypeHistory, curPhase: Phase, curPeriod: Period): TypeHistory = {
assertCorrectThread()
var infos = infos0
var itr = nextFrom(phaseId(_validTo))
infoTransformers = itr; // caching optimization
while (itr.pid != NoPhase.id && itr.pid < curPhase.id) {
phase = phaseWithId(itr.pid)
val info1 = itr.transform(this, infos.info)
if (info1 ne infos.info) {
infos = TypeHistory(currentPeriod + 1, info1, infos)
this.infos = infos
}
_validTo = currentPeriod + 1 // to enable reads from same symbol during info-transform
itr = itr.next
}
_validTo = if (itr.pid == NoPhase.id) curPeriod
else period(currentRunId, itr.pid)
infos
}
// adapt to new run in fsc.
private def adaptInfo(oldest: TypeHistory): Unit = {
assert(isCompilerUniverse, "Must be compiler universe")
assert(oldest.prev == null, "Previous history must be null")
val pid = phaseId(oldest.validFrom)
_validTo = period(currentRunId, pid)
phase = phaseWithId(pid)
val info1 = adaptToNewRunMap(oldest.info)
if (info1 eq oldest.info) {
oldest.validFrom = validTo
this.infos = oldest
} else {
if (this.infos ne null) {
this.infos = this.infos.reset(validTo, info1)
} else
this.infos = TypeHistory(validTo, info1, null)
}
}
/** Raises a `MissingRequirementError` if this symbol is a `StubSymbol` */
def failIfStub(): Unit = {}
/** Initialize the symbol */
final def initialize: this.type = {
if (!isInitialized) info
this
}
def maybeInitialize = {
try { initialize ; true }
catch { case _: CyclicReference => debuglog(s"Hit cycle in maybeInitialize of $this") ; false }
}
/** Was symbol's type updated during given phase? */
final def hasTypeAt(pid: Phase#Id): Boolean = {
assert(isCompilerUniverse, "Must be compiler universe")
var infos = this.infos
while ((infos ne null) && phaseId(infos.validFrom) > pid) infos = infos.prev
infos ne null
}
/** Modify term symbol's type so that a raw type C is converted to an existential C[_]
*
* This is done in checkAccessible and overriding checks in refchecks
* We can't do this on class loading because it would result in infinite cycles.
*/
def cookJavaRawInfo(): this.type = {
// only try once...
if (phase.erasedTypes || (this hasFlag TRIEDCOOKING))
return this
this setFlag TRIEDCOOKING
info // force the current info
if (isJavaDefined || isType && owner.isJavaDefined)
this modifyInfo rawToExistential
else if (isOverloaded) {
for (alt <- alternatives) {
alt.setFlag(TRIEDCOOKING)
if (alt.isJavaDefined) alt.modifyInfo(rawToExistential)
}
}
this
}
/** The logic approximately boils down to finding the most recent phase
* which immediately follows any of parser, namer, typer, or erasure.
* In effect that means this will return one of:
*
* - packageobjects (follows namer)
* - superaccessors (follows typer)
* - lambdaLift (follows erasure)
* - null
*/
private def unsafeTypeParamPhase = {
var ph = phase
while (ph.prev.keepsTypeParams)
ph = ph.prev
ph
}
/** The type parameters of this symbol, without ensuring type completion.
* assumption: if a type starts out as monomorphic, it will not acquire
* type parameters later.
*/
// NOTE: overridden in SynchronizedSymbols with the code copy/pasted
// don't forget to modify the code over there if you modify this method
def unsafeTypeParams: List[Symbol] =
if (isMonomorphicType) Nil
else enteringPhase(unsafeTypeParamPhase)(rawInfo.typeParams)
/** The type parameters of this symbol.
* assumption: if a type starts out as monomorphic, it will not acquire
* type parameters later.
*/
// NOTE: overridden in SynchronizedSymbols with the code copy/pasted
// don't forget to modify the code over there if you modify this method
def typeParams: List[Symbol] = {
def completeTypeParams = {
if (isMonomorphicType) Nil
else {
// analogously to the "info" getter, here we allow for two completions:
// one: sourceCompleter to LazyType, two: LazyType to completed type
enteringPhase(phaseOf(infos.validFrom))(rawInfo load this)
if (validTo == NoPeriod)
enteringPhase(phaseOf(infos.validFrom))(rawInfo load this)
rawInfo.typeParams
}
}
if (validTo != NoPeriod) rawInfo.typeParams else completeTypeParams
}
/** The value parameter sections of this symbol.
*/
def paramss: List[List[Symbol]] = info.paramss
/** The least proper supertype of a class; includes all parent types
* and refinement where needed. You need to compute that in a situation like this:
* {
* class C extends P { ... }
* new C
* }
*/
def classBound: Type = {
val tp = refinedType(info.parents, owner)
// scala/bug#4589 refinedType only creates a new refinement class symbol before erasure; afterwards
// the first parent class is returned, to which we must not add members.
if (!phase.erasedTypes) {
val thistp = tp.typeSymbol.thisType
val oldsymbuf = new ListBuffer[Symbol]
val newsymbuf = new ListBuffer[Symbol]
for (sym <- info.decls) {
// todo: what about public references to private symbols?
if (sym.isPublic && !sym.isConstructor) {
oldsymbuf += sym
newsymbuf += (
if (sym.isClass)
tp.typeSymbol.newAbstractType(sym.name.toTypeName, sym.pos).setInfo(sym.existentialBound)
else
sym.cloneSymbol(tp.typeSymbol))
}
}
val oldsyms = oldsymbuf.toList
val newsyms = newsymbuf.toList
for (sym <- newsyms)
addMember(thistp, tp, sym.modifyInfo(_.substThisAndSym(this, thistp, oldsyms, newsyms)))
}
tp
}
/** If we quantify existentially over this symbol,
* the bound of the type variable that stands for it
* pre: symbol is a term, a class, or an abstract type (no alias type allowed)
*/
def existentialBound: Type
/** Reset symbol to initial state
*/
def reset(completer: Type): this.type = {
resetFlags()
infos = null
_validTo = NoPeriod
//limit = NoPhase.id
setInfo(completer)
}
/**
* Adds the interface java.io.Serializable to the parents of a ClassInfoType.
* Note that the tree also has to be updated accordingly.
*/
def makeSerializable(): Unit = {
info match {
case ci @ ClassInfoType(_, _, _) =>
setInfo(ci.copy(parents = ci.parents :+ SerializableTpe))
invalidateCaches(ci.typeSymbol.typeOfThis, ci.typeSymbol :: Nil)
case i =>
abort("Only ClassInfoTypes can be made serializable: "+ i)
}
}
// ----- setters implemented in selected subclasses -------------------------------------
def typeOfThis_=(tp: Type): Unit = { throw new UnsupportedOperationException("typeOfThis_= inapplicable for " + this) }
def sourceModule_=(sym: Symbol): Unit = { throw new UnsupportedOperationException("sourceModule_= inapplicable for " + this) }
def addChild(sym: Symbol): Unit = { throw new UnsupportedOperationException("addChild inapplicable for " + this) }
// ----- annotations ------------------------------------------------------------
// null is a marker that they still need to be obtained.
private[this] var _annotations: List[AnnotationInfo] = Nil
def annotationsString = if (annotations.isEmpty) "" else annotations.mkString("(", ", ", ")")
/** After the typer phase (before, look at the definition's Modifiers), contains
* the annotations attached to member a definition (class, method, type, field).
*/
def annotations: List[AnnotationInfo] = {
_annotations
}
def setAnnotations(annots: List[AnnotationInfo]): this.type = {
_annotations = annots
this
}
def withAnnotations(annots: List[AnnotationInfo]): this.type =
setAnnotations(annots ::: annotations)
def withAnnotation(anno: AnnotationInfo): this.type =
setAnnotations(anno :: annotations)
def withoutAnnotations: this.type =
setAnnotations(Nil)
def filterAnnotations(p: AnnotationInfo => Boolean): this.type =
setAnnotations(annotations filter p)
def addAnnotation(annot: AnnotationInfo): this.type =
setAnnotations(annot :: annotations)
// Convenience for the overwhelmingly common cases, and avoid varags and listbuilders
final def addAnnotation(sym: Symbol): this.type = {
addAnnotation(sym, Nil)
}
final def addAnnotation(sym: Symbol, arg: Tree): this.type = {
addAnnotation(sym, arg :: Nil)
}
final def addAnnotation(sym: Symbol, arg1: Tree, arg2: Tree): this.type = {
addAnnotation(sym, arg1 :: arg2 :: Nil)
}
final def addAnnotation(sym: Symbol, args: Tree*): this.type = {
addAnnotation(sym, args.toList)
}
final def addAnnotation(sym: Symbol, args: List[Tree]): this.type = {
// The assertion below is meant to prevent from issues like scala/bug#7009 but it's disabled
// due to problems with cycles while compiling Scala library. It's rather shocking that
// just checking if sym is monomorphic type introduces nasty cycles. We are definitively
// forcing too much because monomorphism is a local property of a type that can be checked
// syntactically
// assert(sym.initialize.isMonomorphicType, sym)
addAnnotation(AnnotationInfo(sym.tpe, args, Nil))
}
/** Use that variant if you want to pass (for example) an applied type */
final def addAnnotation(tp: Type): this.type = {
addAnnotation(tp, Nil)
}
final def addAnnotation(tp: Type, arg: Tree): this.type = {
addAnnotation(tp, arg:: Nil)
}
final def addAnnotation(tp: Type, arg1: Tree, arg2: Tree): this.type = {
addAnnotation(tp, arg1 :: arg2 :: Nil)
}
final def addAnnotation(tp: Type, args: List[Tree]): this.type = {
assert(tp.typeParams.isEmpty, tp)
addAnnotation(AnnotationInfo(tp, args, Nil))
}
// ------ comparisons ----------------------------------------------------------------
/** A total ordering between symbols that refines the class
* inheritance graph (i.e. subclass.isLess(superclass) always holds).
* the ordering is given by: (_.isType, -_.baseTypeSeq.length) for type symbols, followed by `id`.
*/
final def isLess(that: Symbol): Boolean = (this ne that) && {
def baseTypeSeqLength(sym: Symbol) =
if (sym.isAbstractType) 1 + sym.info.upperBound.baseTypeSeq.length
else sym.info.baseTypeSeq.length
if (this.isType)
(that.isType &&
{ val diff = baseTypeSeqLength(this) - baseTypeSeqLength(that)
diff > 0 || diff == 0 && this.id < that.id })
else
that.isType || this.id < that.id
}
/** A partial ordering between symbols.
* (this isNestedIn that) holds iff this symbol is defined within
* a class or method defining that symbol
*/
@tailrec
final def isNestedIn(that: Symbol): Boolean =
owner == that || owner != NoSymbol && (owner isNestedIn that)
/** Is this class symbol a subclass of that symbol,
* and is this class symbol also different from Null or Nothing? */
def isNonBottomSubClass(that: Symbol): Boolean = false
/** Is this class symbol Null or Nothing,
* and (if Null) is `that` inhabited by null?
* If this is Nothing, of course, it is a
* subclass of `that` by definition.
*
* TODO - what is implied by the fact that AnyVal now has
* infinitely many non-bottom subclasses, not only 9?
*/
def isBottomSubClass(that: Symbol) = (
(this eq NothingClass)
|| (this eq NullClass) && that.isClass && (that ne NothingClass) && !(that isNonBottomSubClass AnyValClass)
)
/** Overridden in NullClass and NothingClass for custom behavior.
*/
def isSubClass(that: Symbol) = isNonBottomSubClass(that)
final def isNumericSubClass(that: Symbol): Boolean =
definitions.isNumericSubClass(this, that)
final def isWeakSubClass(that: Symbol) =
isSubClass(that) || isNumericSubClass(that)
// ------ overloaded alternatives ------------------------------------------------------
def alternatives: List[Symbol] =
if (isOverloaded) info.asInstanceOf[OverloadedType].alternatives
else this :: Nil
def filter(cond: Symbol => Boolean): Symbol =
if (isOverloaded) {
var changed = false
var alts0: List[Symbol] = alternatives
var alts1: List[Symbol] = Nil
while (!alts0.isEmpty) {
if (cond(alts0.head))
alts1 ::= alts0.head
else
changed = true
alts0 = alts0.tail
}
if (!changed) this
else if (alts1.isEmpty) NoSymbol
else if (alts1.tail.isEmpty) alts1.head
else owner.newOverloaded(info.prefix, alts1.reverse)
}
else if (cond(this)) this
else NoSymbol
def suchThat(cond: Symbol => Boolean): Symbol = {
val result = filter(cond)
assert(!result.isOverloaded, result.alternatives)
result
}
// ------ cloning -------------------------------------------------------------------
/** A clone of this symbol. */
final def cloneSymbol: TypeOfClonedSymbol =
cloneSymbol(owner)
/** A clone of this symbol, but with given owner. */
final def cloneSymbol(newOwner: Symbol): TypeOfClonedSymbol =
cloneSymbol(newOwner, _rawflags)
final def cloneSymbol(newOwner: Symbol, newFlags: Long): TypeOfClonedSymbol =
cloneSymbol(newOwner, newFlags, null)
final def cloneSymbol(newOwner: Symbol, newFlags: Long, newName: Name): TypeOfClonedSymbol = {
val clone = cloneSymbolImpl(newOwner, newFlags)
( clone
setPrivateWithin privateWithin
setInfo (this.info cloneInfo clone)
setAnnotations this.annotations
)
assert(clone.attachments.isEmpty, "cloned symbol cannot have attachments")
clone.setAttachments(this.attachments.cloneAttachments)
if (clone.thisSym != clone)
clone.typeOfThis = (clone.typeOfThis cloneInfo clone)
if (newName ne null)
clone setName asNameType(newName)
clone
}
/** Internal method to clone a symbol's implementation with the given flags and no info. */
def cloneSymbolImpl(owner: Symbol, newFlags: Long): TypeOfClonedSymbol
def flipped: Symbol = this
// ------ access to related symbols --------------------------------------------------
/** The next enclosing class. */
def enclClass: Symbol = if (isClass) this else owner.enclClass
/** The next enclosing method. */
def enclMethod: Symbol = if (isSourceMethod) this else owner.enclMethod
/** The primary constructor of a class. */
def primaryConstructor: Symbol = NoSymbol
/** The self symbol (a TermSymbol) of a class with explicit self type, or else the
* symbol itself (a TypeSymbol).
*
* WARNING: you're probably better off using typeOfThis, as it's more uniform across classes with and without self variables.
*
* Example by Paul:
* scala> trait Foo1 { }
* scala> trait Foo2 { self => }
* scala> intp("Foo1").thisSym
* res0: $r.intp.global.Symbol = trait Foo1
*
* scala> intp("Foo2").thisSym
* res1: $r.intp.global.Symbol = value self
*
* Martin says: The reason `thisSym` is `this` is so that thisType can be this.thisSym.tpe.
* It's a trick to shave some cycles off.
*
* Morale: DO: if (clazz.typeOfThis.typeConstructor ne clazz.typeConstructor) ...
* DON'T: if (clazz.thisSym ne clazz) ...
*
*/
def thisSym: Symbol = this
def hasSelfType = (thisSym ne this) && (typeOfThis.typeConstructor ne typeConstructor)
/** The type of `this` in a class, or else the type of the symbol itself. */
def typeOfThis = thisSym.tpe_*
/** If symbol is a class, the type `this.type` in this class,
* otherwise `NoPrefix`.
* We always have: thisType <:< typeOfThis
*/
def thisType: Type = NoPrefix
/** For a case class, the symbols of the accessor methods, one for each
* argument in the first parameter list of the primary constructor.
* The empty list for all other classes.
*
* This list will be sorted to correspond to the declaration order
* in the constructor parameter
*/
final def caseFieldAccessors: List[Symbol] = {
// We can't rely on the ordering of the case field accessors within decls --
// handling of non-public parameters seems to change the order (see scala/bug#7035.)
//
// Luckily, the constrParamAccessors are still sorted properly, so sort the field-accessors using them
// (need to undo name-mangling, including the sneaky trailing whitespace, and match longest first)
//
// The slightly more principled approach of using the paramss of the
// primary constructor leads to cycles in, for example, pos/t5084.scala.
val primaryNames = constrParamAccessors map (_.name.dropLocal)
def nameStartsWithOrigDollar(name: Name, prefix: Name) =
name.startsWith(prefix) && name.length > prefix.length + 1 && name.charAt(prefix.length) == '$'
def rec(remaningAccessors: List[Symbol], foundAccessors: List[(Symbol, Int)], remainingNames: List[(Name, Int)]): List[Symbol] = {
remaningAccessors match {
case Nil => foundAccessors.sortBy(_._2).map(_._1)
case acc :: tail => {
val i = remainingNames.collectFirst { case (name, i) if acc.name == name || nameStartsWithOrigDollar(acc.name, name) => i}
rec(tail, (acc, i.get) :: foundAccessors, remainingNames.filterNot { case (_, ii) => Some(ii) == i} )
}
}
}
rec(caseFieldAccessorsUnsorted.sortBy(s => -s.name.length), Nil, primaryNames.zipWithIndex.sortBy{ case (n, _) => -n.length})
}
private final def caseFieldAccessorsUnsorted: List[Symbol] = info.decls.toList.filter(_.isCaseAccessorMethod)
final def constrParamAccessors: List[Symbol] = info.decls.toList.filter(sym => !sym.isMethod && sym.isParamAccessor)
/** The symbol accessed by this accessor (getter or setter) function. */
final def accessed: Symbol = {
assert(hasAccessorFlag, this)
val localField = owner.info decl localName
if (localField == NoSymbol && this.hasFlag(MIXEDIN)) { // TODO: fields phase does not (yet?) add MIXEDIN in setMixedinAccessorFlags
// scala/bug#8087: private[this] fields don't have a `localName`. When searching the accessed field
// for a mixin accessor of such a field, we need to look for `name` instead.
// The phase travel ensures that the field is found (`owner` is the trait class symbol, the
// field gets removed from there in later phases).
enteringPhase(picklerPhase)(owner.info).decl(name).suchThat(!_.isAccessor)
} else {
localField
}
}
/** The module corresponding to this module class (note that this
* is not updated when a module is cloned), or NoSymbol if this is not a ModuleClass.
*/
def sourceModule: Symbol = NoSymbol
/** The class that is logically an outer class of given `clazz`.
* This is the enclosing class, except for classes defined locally to constructors,
* where it is the outer class of the enclosing class.
*/
@tailrec
final def outerClass: Symbol =
if (this == NoSymbol) {
// ideally we shouldn't get here, but it's better to harden against this than suffer the infinite loop in scala/bug#9133
devWarningDumpStack("NoSymbol.outerClass", 15)
NoSymbol
} else if (owner.isClass) owner
else if (isClassLocalToConstructor) owner.enclClass.outerClass
else owner.outerClass
/** For a paramaccessor: a superclass paramaccessor for which this symbol
* is an alias, NoSymbol for all others.
*/
def alias: Symbol = NoSymbol
@deprecated("No longer applicable, as lazy vals are not desugared until the fields phase", "2.12.0") // used by scala-refactoring
def lazyAccessor: Symbol = NoSymbol
@deprecated("No longer applicable, as lazy vals are not desugared until the fields phase", "2.12.0")
def lazyAccessorOrSelf: Symbol = NoSymbol
/** `accessed`, if this is an accessor that should have an underlying field. Otherwise, `this`.
* Note that a "regular" accessor in a trait does not have a field, as an interface cannot define a field.
* "non-regular" vals are: early initialized or lazy vals.
* Eventually, we should delay introducing symbols for all val/vars until the fields (or lazyvals) phase,
* as they are an implementation detail that's irrelevant to type checking.
*/
def accessedOrSelf: Symbol =
if (hasAccessorFlag && (!owner.isTrait || hasFlag(PRESUPER))) accessed
else this
/** For an outer accessor: The class from which the outer originates.
* For all other symbols: NoSymbol
*/
def outerSource: Symbol = NoSymbol
/** The superclass of this class. */
def superClass: Symbol = if (info.parents.isEmpty) NoSymbol else info.parents.head.typeSymbol
def parentSymbols: List[Symbol] = info.parents map (_.typeSymbol)
def parentSymbolsIterator: Iterator[Symbol] = info.parents.iterator.map(_.typeSymbol)
/** The directly or indirectly inherited mixins of this class
* except for mixin classes inherited by the superclass. Mixin classes appear
* in linearization order.
*/
def mixinClasses: List[Symbol] = {
val sc = superClass
ancestors takeWhile (sc ne _)
}
/** All directly or indirectly inherited classes. */
def ancestors: List[Symbol] = info.baseClasses drop 1
@inline final def enclosingSuchThat(p: Symbol => Boolean): Symbol = {
var sym = this
while (sym != NoSymbol && !p(sym))
sym = sym.owner
sym
}
/** The package class containing this symbol, or NoSymbol if there
* is not one.
* TODO: formulate as enclosingSuchThat, after making sure
* we can start with current symbol rather than owner.
* TODO: Also harmonize with enclClass, enclMethod etc.
*/
def enclosingPackageClass: Symbol = {
var sym = this.owner
while (sym != NoSymbol && !sym.isPackageClass)
sym = sym.owner
sym
}
/** The package class containing this symbol, or NoSymbol if there
* is not one. */
def enclosingRootClass: Symbol = enclosingSuchThat(_.isRoot)
/** The package containing this symbol, or NoSymbol if there
* is not one. */
def enclosingPackage: Symbol = enclosingPackageClass.companionModule
/** The method or class which logically encloses the current symbol.
* If the symbol is defined in the initialization part of a template
* this is the template's primary constructor, otherwise it is
* the physically enclosing method or class.
*
* Example 1:
*
* def f() { val x = { def g() = ...; g() } }
*
* In this case the owner chain of `g` is `x`, followed by `f` and
* `g.logicallyEnclosingMember == f`.
*
* Example 2:
*
* class C {
* def = { ... }
* val x = { def g() = ...; g() } }
* }
*
* In this case the owner chain of `g` is `x`, followed by `C` but
* g.logicallyEnclosingMember is the primary constructor symbol ``
* (or, for traits: `$init`) of `C`.
*
*/
@tailrec
final def logicallyEnclosingMember: Symbol =
if (isLocalDummy) enclClass.primaryConstructor
else if (isMethod || isClass || this == NoSymbol) this
else owner.logicallyEnclosingMember
/** The top-level class containing this symbol, using the current owner chain. */
@tailrec
final def enclosingTopLevelClass: Symbol =
if (this eq NoSymbol) this
else if (isTopLevel) {
if (isClass) this else moduleClass
} else owner.enclosingTopLevelClass
/** The top-level class or local dummy symbol containing this symbol, using the original owner chain. */
@tailrec
final def originalEnclosingTopLevelClassOrDummy: Symbol =
if (this eq NoSymbol) this
else if (isTopLevel) {
if (isClass) this else moduleClass.orElse(this)
} else originalOwner.originalEnclosingTopLevelClassOrDummy
/** Is this symbol defined in the same scope and compilation unit as `that` symbol? */
def isCoDefinedWith(that: Symbol) = {
!rawInfoIsNoType &&
(this.effectiveOwner == that.effectiveOwner) &&
(!this.effectiveOwner.isPackageClass || { val thisFile = this.associatedFile
(thisFile eq NoAbstractFile) || { val thatFile = that.associatedFile
(thatFile eq NoAbstractFile) ||
(thisFile.path == thatFile.path) || // Cheap possibly wrong check
(thisFile.canonicalPath == thatFile.canonicalPath)
}}
)
}
/** The internal representation of classes and objects:
*
* class Foo is "the class" or sometimes "the plain class"
* object Foo is "the module"
* class Foo$ is "the module class" (invisible to the user: it implements object Foo)
*
* class Foo <
* ^ ^ (2) \
* | | | \
* | (5) | (3)
* | | | \
* (1) v v \
* object Foo (4)-> > class Foo$
*
* (1) companionClass
* (2) companionModule
* (3) linkedClassOfClass
* (4) moduleClass
* (5) companionSymbol
*/
/** For a module: the class with the same name in the same package.
* For all others: NoSymbol
* Note: does not work for classes owned by methods, see Namers.companionClassOf
*
* object Foo . companionClass --> class Foo
*
* !!! linkedClassOfClass depends on companionClass on the module class getting
* to the class. As presently implemented this potentially returns class for
* any symbol except NoSymbol.
*/
def companionClass: Symbol = flatOwnerInfo.decl(name.toTypeName).suchThat(d => d.isClass && d.isCoDefinedWith(this))
/** For a class: the module or case class factory with the same name in the same package.
* For all others: NoSymbol
* Note: does not work for modules owned by methods, see Namers.companionModuleOf
*
* class Foo . companionModule --> object Foo
*/
def companionModule: Symbol = NoSymbol
/** For a module: its linked class
* For a plain class: its linked module or case factory.
* Note: does not work for modules owned by methods, see Namers.companionSymbolOf
*
* class Foo <-- companionSymbol --> object Foo
*/
def companionSymbol: Symbol = NoSymbol
/** For a module class: its linked class
* For a plain class: the module class of its linked module.
*
* class Foo <-- linkedClassOfClass --> class Foo$
*/
def linkedClassOfClass: Symbol = NoSymbol
/**
* Returns the rawInfo of the owner. If the current phase has flat classes,
* it first applies all pending type maps to this symbol.
*
* assume this is the ModuleSymbol for B in the following definition:
* package p { class A { object B { val x = 1 } } }
*
* The owner after flatten is "package p" (see "def owner"). The flatten type map enters
* symbol B in the decls of p. So to find a linked symbol ("object B" or "class B")
* we need to apply flatten to B first. Fixes #2470.
*/
protected final def flatOwnerInfo: Type = {
if (needsFlatClasses)
info
owner.rawInfo
}
/** The module class corresponding to this module.
*/
def moduleClass: Symbol = NoSymbol
/** The non-private symbol whose type matches the type of this symbol
* in in given class.
*
* @param ofclazz The class containing the symbol's definition
* @param site The base type from which member types are computed
*/
final def matchingSymbol(ofclazz: Symbol, site: Type): Symbol =
matchingSymbolInternal(site, ofclazz.info nonPrivateDecl name)
/** The non-private member of `site` whose type and name match the type of this symbol. */
final def matchingSymbol(site: Type, admit: Long = 0L): Symbol =
matchingSymbolInternal(site, site.nonPrivateMemberAdmitting(name, admit))
private def matchingSymbolInternal(site: Type, candidate: Symbol): Symbol = {
def qualifies(sym: Symbol) = !sym.isTerm || ((site memberType this) matches (site memberType sym))
//OPT Fast past for NoSymbol. Cut down on #closures by special casing non-overloaded case
if (candidate == NoSymbol) NoSymbol
else if (candidate.isOverloaded) candidate filter qualifies
else if (qualifies(candidate)) candidate
else NoSymbol
}
/** The symbol, in class `baseClass`, that is overridden by this symbol.
*
* @param baseClass is a base class of this symbol's owner.
*/
final def overriddenSymbol(baseClass: Symbol): Symbol = {
// concrete always overrides abstract, so don't let an abstract definition
// claim to be overriding an inherited concrete one.
val matching = matchingInheritedSymbolIn(baseClass)
if (isDeferred) matching.filter(_.isDeferred) else matching
}
private def matchingInheritedSymbolIn(baseClass: Symbol): Symbol =
if (canMatchInheritedSymbols) matchingSymbol(baseClass, owner.thisType) else NoSymbol
/** The symbol overriding this symbol in given subclass `ofclazz`.
*
* @param ofclazz is a subclass of this symbol's owner
*/
final def overridingSymbol(ofclazz: Symbol): Symbol = (
if (canMatchInheritedSymbols)
matchingSymbol(ofclazz, ofclazz.thisType)
else
NoSymbol
)
/** If false, this symbol cannot possibly participate in an override,
* either as overrider or overridee. For internal use; you should consult
* with isOverridingSymbol. This is used by isOverridingSymbol to escape
* the recursive knot.
*/
private def canMatchInheritedSymbols = (
owner.isClass
&& !this.isClass
&& !this.isConstructor
)
// All the symbols overridden by this symbol and this symbol at the head,
// or Nil if this is NoSymbol.
def overrideChain = (
if (this eq NoSymbol) Nil
else if (isOverridingSymbol) this :: allOverriddenSymbols
else this :: Nil
)
/** Returns all symbols overridden by this symbol. */
final def allOverriddenSymbols: List[Symbol] = {
if (isOverridingSymbol) {
// performance sensitive
val builder = List.newBuilder[Symbol]
for (o <- owner.ancestors) {
overriddenSymbol(o).andAlso(builder += _)
}
builder.result()
} else Nil
}
private[this] var isOverridingSymbolCache = 0
/** Equivalent to allOverriddenSymbols.nonEmpty, but more efficient. */
private def computeIsOverridingSymbol: Boolean = (
canMatchInheritedSymbols
&& owner.ancestors.exists(base => overriddenSymbol(base) != NoSymbol)
)
final def isOverridingSymbol: Boolean = {
val curRunId = currentRunId
// TODO this cache can lead to incorrect answers if the overrider/overridee relationship changes
// with the passage of compiler phases. Details: https://github.com/scala/scala/pull/6197#discussion_r161427280
// When fixing this problem (e.g. by ignoring the cache after erasure?), be mindful of performance
if (isOverridingSymbolCache == curRunId) true
else if (isOverridingSymbolCache == -curRunId) false
else {
val result = computeIsOverridingSymbol
isOverridingSymbolCache = (if (result) 1 else -1) * curRunId
result
}
}
/** Equivalent to allOverriddenSymbols.head (or NoSymbol if no overrides) but more efficient. */
def nextOverriddenSymbol: Symbol = {
@tailrec def loop(bases: List[Symbol]): Symbol = bases match {
case Nil => NoSymbol
case base :: rest =>
val sym = overriddenSymbol(base)
if (sym == NoSymbol) loop(rest) else sym
}
if (isOverridingSymbol) loop(owner.ancestors) else NoSymbol
}
/** Returns all symbols overridden by this symbol, plus all matching symbols
* defined in parents of the selftype.
*/
final def extendedOverriddenSymbols: List[Symbol] = (
if (canMatchInheritedSymbols)
owner.thisSym.ancestors map overriddenSymbol filter (_ != NoSymbol)
else
Nil
)
@deprecated("use `superSymbolIn` instead", "2.11.0")
final def superSymbol(base: Symbol): Symbol = superSymbolIn(base)
/** 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): Symbol = {
var bcs = base.info.baseClasses dropWhile (owner != _) drop 1
var sym: Symbol = NoSymbol
while (!bcs.isEmpty && sym == NoSymbol) {
sym = matchingSymbol(bcs.head, base.thisType).suchThat(!_.isDeferred)
bcs = bcs.tail
}
sym
}
@deprecated("use `getterIn` instead", "2.11.0")
final def getter(base: Symbol): Symbol = getterIn(base)
/** The getter of this value or setter definition in class `base`, or NoSymbol if none exists. */
final def getterIn(base: Symbol): Symbol =
base.info decl getterName filter (_.hasAccessorFlag)
def getterName: TermName = name.getterName
def setterName: TermName = name.setterName
def localName: TermName = name.localName
@deprecated("use `setterIn` instead", "2.11.0")
final def setter(base: Symbol, hasExpandedName: Boolean = needsExpandedSetterName): Symbol =
setterIn(base, hasExpandedName)
/** The setter of this value or getter definition, or NoSymbol if none exists. */
final def setterIn(base: Symbol, hasExpandedName: Boolean = needsExpandedSetterName): Symbol =
base.info decl setterNameInBase(base, hasExpandedName) filter (_.hasAccessorFlag)
def needsExpandedSetterName = (
if (isMethod) hasStableFlag && !isLazy
else hasNoFlags(LAZY | MUTABLE)
)
def setterNameInBase(base: Symbol, expanded: Boolean): TermName =
if (expanded) nme.expandedSetterName(setterName, base) else setterName
/** If this is a derived value class, return its unbox method
* or NoSymbol if it does not exist.
*/
def derivedValueClassUnbox: Symbol = NoSymbol
/** The case module corresponding to this case class
* @pre case class is a member of some other class or package
*/
final def caseModule: Symbol = {
var modname = name.toTermName
val pw = privateWithin
if (pw.isClass && !pw.isModuleClass && !hasFlag(EXPANDEDNAME))
modname = nme.expandedName(modname, pw)
initialize.owner.info.decl(modname).suchThat(_.isModule)
}
/** If this symbol is a type parameter skolem (not an existential skolem!)
* its corresponding type parameter, otherwise this */
def deSkolemize: Symbol = this
/** If this symbol is an existential skolem the location (a Tree or null)
* where it was unpacked. Resulttype is AnyRef because trees are not visible here. */
def unpackLocation: AnyRef = null
/** Remove private modifier from symbol `sym`s definition. If `sym` is a
* is not a constructor nor a static module rename it by expanding its name to avoid name clashes
* @param base the fully qualified name of this class will be appended if name expansion is needed
*/
@tailrec
final def makeNotPrivate(base: Symbol): Unit = {
if (this.isPrivate) {
setFlag(notPRIVATE) // this makes it effectively final (isEffectivelyFinal)
// don't set FINAL -- methods not marked final by user should not end up final in bytecode
// inliner will know it's effectively final (notPRIVATE non-deferred method)
if (!isStaticModule && !isClassConstructor) {
expandName(base)
if (isModule) moduleClass.makeNotPrivate(base)
}
}
}
/** Remove any access boundary and clear flags PROTECTED | PRIVATE.
*/
def makePublic = this setPrivateWithin NoSymbol resetFlag AccessFlags
/** The first parameter to the first argument list of this method,
* or NoSymbol if inapplicable.
*/
def firstParam = info.params match {
case p :: _ => p
case _ => NoSymbol
}
// Desire to re-use the field in ClassSymbol which stores the source
// file to also store the classfile, but without changing the behavior
// of sourceFile (which is expected at least in the IDE only to
// return actual source code.) So sourceFile has classfiles filtered out.
final def sourceFile: AbstractFile = {
val file = associatedFile
if (
(file eq NoAbstractFile) || {
val path = file.path
path.endsWith(".class") || path.endsWith(".sig")
}) null else file
}
/** Overridden in ModuleSymbols to delegate to the module class.
* Never null; if there is no associated file, returns NoAbstractFile.
*/
def associatedFile: AbstractFile = enclosingTopLevelClass.associatedFile
def associatedFile_=(f: AbstractFile): Unit = { abort("associatedFile_= inapplicable for " + this) }
/** If this is a sealed or local class, its known direct subclasses.
* Otherwise, the empty set.
*/
def children: Set[Symbol] = Set()
final def sealedChildren: Set[Symbol] = if (!isSealed) Set.empty else children
/** Recursively assemble all children of this symbol.
*/
final def sealedDescendants: Set[Symbol] = if (!isSealed) Set(this) else children.flatMap(_.sealedDescendants) + this
@inline final def orElse(alt: => Symbol): Symbol = if (this ne NoSymbol) this else alt
@inline final def andAlso(f: Symbol => Unit): Symbol = { if (this ne NoSymbol) f(this) ; this }
@inline final def fold[T](none: => T)(f: Symbol => T): T = if (this ne NoSymbol) f(this) else none
@inline final def map(f: Symbol => Symbol): Symbol = if (this eq NoSymbol) this else f(this)
final def toOption: Option[Symbol] = if (exists) Some(this) else None
// ------ toString -------------------------------------------------------------------
/** The simple name of this Symbol */
final def simpleName: Name = name
/** The String used to order otherwise identical sealed symbols.
* This uses data which is stable across runs and variable classpaths
* (the initial Name) before falling back on id, which varies depending
* on exactly when a symbol is loaded.
*/
final def sealedSortName: String = initName.toString + "#" + id
/** String representation of symbol's definition key word */
final def keyString: String =
if (isJavaInterface) "interface"
else if (isTrait) "trait"
else if (isClass) "class"
else if (isType && !isParameter) "type"
else if (isVariable) "var"
else if (hasPackageFlag) "package"
else if (isModule) "object"
else if (isSourceMethod) "def"
else if (isTerm && (!isParameter || isParamAccessor)) "val"
else ""
private def symbolKind: SymbolKind = {
implicit val triple2SK = (SymbolKind.apply _).tupled
val kind: SymbolKind =
if (isTermMacro) ("term macro", "macro method", "MACM")
else if (isInstanceOf[FreeTermSymbol]) ("free term", "free term", "FTE")
else if (isInstanceOf[FreeTypeSymbol]) ("free type", "free type", "FTY")
else if (isPackageClass) ("package class", "package", "PKC")
else if (hasPackageFlag) ("package", "package", "PK")
else if (isPackageObject) ("package object", "package", "PKO")
else if (isPackageObjectClass) ("package object class", "package", "PKOC")
else if (isAnonymousClass) ("anonymous class", "anonymous class", "AC")
else if (isRefinementClass) ("refinement class", "", "RC")
else if (isJavaAnnotation) ("Java annotation", "Java annotation", "JANN")
else if (isJavaEnum
|| companion.isJavaEnum) ("Java enumeration", "Java enum", "JENUM")
else if (isJava && isModule) ("Java module", "class", "JMOD")
else if (isJava && isModuleClass) ("Java module class", "class", "JMODC")
else if (isModule) ("module", "object", "MOD")
else if (isModuleClass) ("module class", "object", "MODC")
else if (isAccessor &&
!hasFlag(STABLE | LAZY)) ("setter", "variable", "SET")
else if (isAccessor && !hasFlag(LAZY)) ("getter", "value", "GET")
else if (isTerm && hasFlag(LAZY)) ("lazy value", "lazy value", "LAZ")
else if (isVariable) ("field", "variable", "VAR")
else if (isTrait) ("trait", "trait", "TRT")
else if (isClass) ("class", "class", "CLS")
else if (isType) ("type", "type", "TPE")
else if (isClassConstructor && (owner.hasCompleteInfo &&
isPrimaryConstructor)) ("primary constructor", "constructor", "PCTOR")
else if (isClassConstructor) ("constructor", "constructor", "CTOR")
else if (isMethod) ("method", "method", "METH")
else if (isTerm) ("value", "value", "VAL")
else ("", "", "???")
if (isSkolem) kind.skolemize else kind
}
/** Accurate string representation of symbols' kind, suitable for developers. */
final def accurateKindString: String =
symbolKind.accurate
/** String representation of symbol's kind, suitable for the masses. */
private def sanitizedKindString: String =
symbolKind.sanitized
/** String representation of symbol's kind, suitable for the masses. */
protected[scala] def abbreviatedKindString: String =
symbolKind.abbreviation
final def kindString: String =
if (settings.isDebug) accurateKindString
else sanitizedKindString
/** If the name of the symbol's owner should be used when you care about
* seeing an interesting name: in such cases this symbol is e.g. a method
* parameter with a synthetic name, a constructor named "this", an object
* "package", etc. The kind string, if non-empty, will be phrased relative
* to the name of the owner.
*/
def hasMeaninglessName = (
isSetterParameter // x$1
|| isClassConstructor // this
|| isRefinementClass //
|| (name == nme.PACKAGE) // package
)
/** String representation of symbol's simple name.
* If !settings.debug translates expansions of operators back to operator symbol.
* E.g. $eq => =.
* If settings.uniqid, adds id.
* If settings.Yshowsymowners, adds owner's id
* If settings.Yshowsymkinds, adds abbreviated symbol kind.
*/
def nameString: String = {
val name_s = if (settings.isDebug) "" + unexpandedName else unexpandedName.dropLocal.decode
val kind_s = if (settings.Yshowsymkinds.value) "#" + abbreviatedKindString else ""
name_s + idString + kind_s
}
def fullNameString: String = {
def recur(sym: Symbol): String = {
if (sym.isRootSymbol || sym == NoSymbol) sym.nameString
else if (sym.owner.isEffectiveRoot) sym.nameString
else recur(sym.effectiveOwner.enclClass) + "." + sym.nameString
}
recur(this)
}
/** If settings.uniqid is set, the symbol's id, else "" */
final def idString = {
val id_s = if (settings.uniqid.value) "#"+id else ""
val owner_s = if (settings.Yshowsymowners.value) "@"+owner.id else ""
id_s + owner_s
}
/** String representation, including symbol's kind e.g., "class Foo", "method Bar".
* If hasMeaninglessName is true, uses the owner's name to disambiguate identity.
*/
override def toString: String = {
val simplifyNames = !settings.isDebug
if (isPackageObjectOrClass && simplifyNames) s"package object ${owner.decodedName}"
else {
val kind = kindString
val _name: String =
if (hasMeaninglessName) owner.decodedName + idString
else if (simplifyNames && (kind == "variable" || kind == "value")) unexpandedName.getterName.decode.toString // TODO: make condition less gross?
else nameString
compose(kind, _name)
}
}
/** String representation of location.
*/
def ownsString: String = {
val owns = effectiveOwner
if (owns.isClass && !owns.isEmptyPrefix) "" + owns else ""
}
/** String representation of location, plus a preposition. Doesn't do much,
* for backward compatibility reasons.
*/
def locationString: String = ownsString match {
case "" => ""
case s => " in " + s
}
def fullLocationString: String = toString + locationString
def signatureString: String = if (hasRawInfo) infoString(rawInfo) else "<_>"
/** String representation of symbol's definition following its name */
final def infoString(tp: Type): String = {
def loop(tp: Type, followsParens: Boolean): String = {
def isStructuralThisType = owner.isInitialized && owner.isStructuralRefinement && tp == owner.tpe // scala/bug#8158
// colon+space, preceded by an extra space if needed to prevent the colon glomming onto a symbolic name
def postnominalColon: String = if (!followsParens && name.isOperatorName) " : " else ": "
def parents = if (settings.isDebug) parentsString(tp.parents) else briefParentsString(tp.parents)
def typeRest =
if (isClass) " extends " + parents
else if (isAliasType) " = " + tp.resultType
else tp.resultType match {
case rt@TypeBounds(_, _) => "" + rt
case rt => " <: " + rt
}
tp match {
case _ if isType => typeParamsString(tp) + typeRest
case _ if isModule => "" // avoid "object X of type X.type"
case PolyType(tparams, res) => typeParamsString(tp) + loop(res, followsParens = true)
case NullaryMethodType(res) => loop(res, followsParens = false)
case MethodType(params, res) => valueParamsString(tp) + loop(res, followsParens = true)
case _ if isStructuralThisType => postnominalColon + owner.name
case _ => postnominalColon + tp
}
}
loop(tp, followsParens = false)
}
def infosString = infos.toString
def debugLocationString = {
val pre = flagString match {
case "" => ""
case s if s contains ' ' => "(" + s + ") "
case s => s + " "
}
pre + fullLocationString
}
private def defStringCompose(infoString: String) = compose(
flagString,
keyString,
varianceString + nameString + infoString + flagsExplanationString
)
/** String representation of symbol's definition. It uses the
* symbol's raw info to avoid forcing types.
*/
def defString = defStringCompose(signatureString)
def defStringWithoutImplicit = compose(
keyString,
varianceString + nameString + signatureString + flagsExplanationString
)
/** String representation of symbol's definition, using the supplied
* info rather than the symbol's.
*/
def defStringSeenAs(info: Type) = defStringCompose(infoString(info))
/** Concatenate strings separated by spaces */
private def compose(ss: String*) = ss filter (_ != "") mkString " "
def isSingletonExistential: Boolean =
nme.isSingletonName(name)
/** String representation of existentially bound variable */
def existentialToString =
if (isSingletonExistential && !settings.isDebug)
"val " + tpnme.dropSingletonName(name) + ": " + dropSingletonType(info.upperBound)
else defString
}
implicit val SymbolTag = ClassTag[Symbol](classOf[Symbol])
/** A class for term symbols */
class TermSymbol protected[Symbols] (initOwner: Symbol, initPos: Position, initName: TermName)
extends Symbol(initOwner, initPos, initName) with TermSymbolApi {
private[this] var _referenced: Symbol = NoSymbol
privateWithin = NoSymbol
type TypeOfClonedSymbol = TermSymbol
override def name_=(name: Name): Unit = {
if (name != rawname) {
super.name_=(name) // logging
changeNameInOwners(name)
_rawname = name.toTermName
}
}
final def asNameType(n: Name) = n.toTermName
/** Term symbols with the exception of static parts of Java classes and packages.
*/
override def isValue = !(isModule && hasFlag(PACKAGE | JAVA))
override def isVariable = isMutable && !isMethod
override def isTermMacro = hasFlag(MACRO)
def isAnnotationMacro = hasFlag(MACRO) && name == nme.macroTransform && owner.isClass && owner.hasFlag(MACRO)
// interesting only for lambda lift. Captured variables are accessed from inner lambdas.
override def isCapturedVariable = hasAllFlags(MUTABLE | CAPTURED) && !hasFlag(METHOD)
override def companionSymbol: Symbol = companionClass
override def moduleClass = if (isModule) referenced else NoSymbol
override def isBridge = this hasFlag BRIDGE
override def isEarlyInitialized = this hasFlag PRESUPER
override def isMethod = this hasFlag METHOD
override def isModule = this hasFlag MODULE
override def isOverloaded = this hasFlag OVERLOADED
/*** !!! TODO: shouldn't we do something like the following:
override def isOverloaded = (
if (this.isInitialized)
this hasFlag OVERLOADED
else
(infos ne null) && infos.info.isInstanceOf[OverloadedType]
)
***/
override def isValueParameter = this hasFlag PARAM
override def isSetterParameter = isValueParameter && owner.isSetter
override def isDefaultGetter = name containsName nme.DEFAULT_GETTER_STRING
override def isAccessor = this hasFlag ACCESSOR
override def isGetter = isAccessor && !nme.isSetterName(name) // TODO: make independent of name, as this can be forged.
override def isSetter = isAccessor && nme.isSetterName(name) // TODO: make independent of name, as this can be forged.
override def isLocalDummy = nme.isLocalDummyName(name)
override def isClassConstructor = rawname == nme.CONSTRUCTOR
override def isMixinConstructor = rawname == nme.MIXIN_CONSTRUCTOR
override def isConstructor = isClassConstructor || isMixinConstructor
override def isPackageObject = isModule && (rawname == nme.PACKAGE)
// The name in comments is what it is being disambiguated from.
// TODO - rescue CAPTURED from BYNAMEPARAM so we can see all the names.
override def resolveOverloadedFlag(flag: Long) = flag match {
case DEFAULTPARAM => "" // TRAIT
case MIXEDIN => "" // EXISTENTIAL
case LABEL => "