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Compiler for the Scala Programming Language
/* NSC -- new scala compiler
* Copyright 2005-2012 LAMP/EPFL
* @author Martin Odersky
*/
package scala.reflect
package internal
import scala.collection.{ mutable, immutable }
import util._
abstract class SymbolTable extends macros.Universe
with Collections
with Names
with Symbols
with Types
with Kinds
with ExistentialsAndSkolems
with FlagSets
with Scopes
with Mirrors
with Definitions
with Constants
with BaseTypeSeqs
with InfoTransformers
with transform.Transforms
with StdNames
with AnnotationInfos
with AnnotationCheckers
with Trees
with Printers
with Positions
with TypeDebugging
with Importers
with Required
with CapturedVariables
with StdAttachments
with StdCreators
with BuildUtils
{
val gen = new TreeGen { val global: SymbolTable.this.type = SymbolTable.this }
lazy val treeBuild = gen
def log(msg: => AnyRef): Unit
def warning(msg: String): Unit = Console.err.println(msg)
def globalError(msg: String): Unit = abort(msg)
def abort(msg: String): Nothing = throw new FatalError(supplementErrorMessage(msg))
@deprecated("Give us a reason", "2.10.0")
def abort(): Nothing = abort("unknown error")
/** Override with final implementation for inlining. */
def debuglog(msg: => String): Unit = if (settings.debug.value) log(msg)
def debugwarn(msg: => String): Unit = if (settings.debug.value) Console.err.println(msg)
def throwableAsString(t: Throwable): String = "" + t
/** Prints a stack trace if -Ydebug or equivalent was given, otherwise does nothing. */
def debugStack(t: Throwable): Unit = debugwarn(throwableAsString(t))
/** Overridden when we know more about what was happening during a failure. */
def supplementErrorMessage(msg: String): String = msg
private[scala] def printCaller[T](msg: String)(result: T) = {
Console.err.println("%s: %s\nCalled from: %s".format(msg, result,
(new Throwable).getStackTrace.drop(2).take(15).mkString("\n")))
result
}
private[scala] def printResult[T](msg: String)(result: T) = {
Console.err.println(msg + ": " + result)
result
}
@inline
final private[scala] def logResult[T](msg: => String)(result: T): T = {
log(msg + ": " + result)
result
}
@inline
final private[scala] def logResultIf[T](msg: => String, cond: T => Boolean)(result: T): T = {
if (cond(result))
log(msg + ": " + result)
result
}
// For too long have we suffered in order to sort NAMES.
// I'm pretty sure there's a reasonable default for that.
// Notice challenge created by Ordering's invariance.
implicit def lowPriorityNameOrdering[T <: Names#Name]: Ordering[T] =
SimpleNameOrdering.asInstanceOf[Ordering[T]]
private object SimpleNameOrdering extends Ordering[Names#Name] {
def compare(n1: Names#Name, n2: Names#Name) = (
if (n1 eq n2) 0
else n1.toString compareTo n2.toString
)
}
/** Dump each symbol to stdout after shutdown.
*/
final val traceSymbolActivity = sys.props contains "scalac.debug.syms"
object traceSymbols extends {
val global: SymbolTable.this.type = SymbolTable.this
} with util.TraceSymbolActivity
/** Are we compiling for Java SE? */
// def forJVM: Boolean
/** Are we compiling for .NET? */
def forMSIL: Boolean = false
/** A last effort if symbol in a select . is not found.
* This is overridden by the reflection compiler to make up a package
* when it makes sense (i.e. is a package and is a term name).
*/
def missingHook(owner: Symbol, name: Name): Symbol = NoSymbol
/** Returns the mirror that loaded given symbol */
def mirrorThatLoaded(sym: Symbol): Mirror
/** A period is an ordinal number for a phase in a run.
* Phases in later runs have higher periods than phases in earlier runs.
* Later phases have higher periods than earlier phases in the same run.
*/
type Period = Int
final val NoPeriod = 0
/** An ordinal number for compiler runs. First run has number 1. */
type RunId = Int
final val NoRunId = 0
// sigh, this has to be public or atPhase doesn't inline.
var phStack: List[Phase] = Nil
private[this] var ph: Phase = NoPhase
private[this] var per = NoPeriod
final def atPhaseStack: List[Phase] = phStack
final def phase: Phase = {
if (Statistics.hotEnabled)
Statistics.incCounter(SymbolTableStats.phaseCounter)
ph
}
def atPhaseStackMessage = atPhaseStack match {
case Nil => ""
case ps => ps.reverseMap("->" + _).mkString("(", " ", ")")
}
final def phase_=(p: Phase) {
//System.out.println("setting phase to " + p)
assert((p ne null) && p != NoPhase, p)
ph = p
per = period(currentRunId, p.id)
}
final def pushPhase(ph: Phase): Phase = {
val current = phase
phase = ph
phStack ::= ph
current
}
final def popPhase(ph: Phase) {
phStack = phStack.tail
phase = ph
}
/** The current compiler run identifier. */
def currentRunId: RunId
/** The run identifier of the given period. */
final def runId(period: Period): RunId = period >> 8
/** The phase identifier of the given period. */
final def phaseId(period: Period): Phase#Id = period & 0xFF
/** The period at the start of run that includes `period`. */
final def startRun(period: Period): Period = period & 0xFFFFFF00
/** The current period. */
final def currentPeriod: Period = {
//assert(per == (currentRunId << 8) + phase.id)
per
}
/** The phase associated with given period. */
final def phaseOf(period: Period): Phase = phaseWithId(phaseId(period))
final def period(rid: RunId, pid: Phase#Id): Period =
(rid << 8) + pid
/** Are we later than given phase in compilation? */
final def isAtPhaseAfter(p: Phase) =
p != NoPhase && phase.id > p.id
/** Perform given operation at given phase. */
@inline final def atPhase[T](ph: Phase)(op: => T): T = {
val saved = pushPhase(ph)
try op
finally popPhase(saved)
}
/** Since when it is to be "at" a phase is inherently ambiguous,
* a couple unambiguously named methods.
*/
@inline final def beforePhase[T](ph: Phase)(op: => T): T = atPhase(ph)(op)
@inline final def afterPhase[T](ph: Phase)(op: => T): T = atPhase(ph.next)(op)
@inline final def afterCurrentPhase[T](op: => T): T = atPhase(phase.next)(op)
@inline final def beforePrevPhase[T](op: => T): T = atPhase(phase.prev)(op)
@inline final def atPhaseNotLaterThan[T](target: Phase)(op: => T): T =
if (isAtPhaseAfter(target)) atPhase(target)(op) else op
final def isValid(period: Period): Boolean =
period != 0 && runId(period) == currentRunId && {
val pid = phaseId(period)
if (phase.id > pid) infoTransformers.nextFrom(pid).pid >= phase.id
else infoTransformers.nextFrom(phase.id).pid >= pid
}
final def isValidForBaseClasses(period: Period): Boolean = {
def noChangeInBaseClasses(it: InfoTransformer, limit: Phase#Id): Boolean = (
it.pid >= limit ||
!it.changesBaseClasses && noChangeInBaseClasses(it.next, limit)
);
period != 0 && runId(period) == currentRunId && {
val pid = phaseId(period)
if (phase.id > pid) noChangeInBaseClasses(infoTransformers.nextFrom(pid), phase.id)
else noChangeInBaseClasses(infoTransformers.nextFrom(phase.id), pid)
}
}
def openPackageModule(container: Symbol, dest: Symbol) {
// unlink existing symbols in the package
for (member <- container.info.decls.iterator) {
if (!member.isPrivate && !member.isConstructor) {
// todo: handle overlapping definitions in some way: mark as errors
// or treat as abstractions. For now the symbol in the package module takes precedence.
for (existing <- dest.info.decl(member.name).alternatives)
dest.info.decls.unlink(existing)
}
}
// enter non-private decls the class
for (member <- container.info.decls.iterator) {
if (!member.isPrivate && !member.isConstructor) {
dest.info.decls.enter(member)
}
}
// enter decls of parent classes
for (p <- container.parentSymbols) {
if (p != definitions.ObjectClass) {
openPackageModule(p, dest)
}
}
}
/** Convert array parameters denoting a repeated parameter of a Java method
* to `JavaRepeatedParamClass` types.
*/
def arrayToRepeated(tp: Type): Type = tp match {
case MethodType(params, rtpe) =>
val formals = tp.paramTypes
assert(formals.last.typeSymbol == definitions.ArrayClass, formals)
val method = params.last.owner
val elemtp = formals.last.typeArgs.head match {
case RefinedType(List(t1, t2), _) if (t1.typeSymbol.isAbstractType && t2.typeSymbol == definitions.ObjectClass) =>
t1 // drop intersection with Object for abstract types in varargs. UnCurry can handle them.
case t =>
t
}
val newParams = method.newSyntheticValueParams(formals.init :+ definitions.javaRepeatedType(elemtp))
MethodType(newParams, rtpe)
case PolyType(tparams, rtpe) =>
PolyType(tparams, arrayToRepeated(rtpe))
}
abstract class SymLoader extends LazyType {
def fromSource = false
}
/** if there's a `package` member object in `pkgClass`, enter its members into it. */
def openPackageModule(pkgClass: Symbol) {
val pkgModule = pkgClass.info.decl(nme.PACKAGEkw)
def fromSource = pkgModule.rawInfo match {
case ltp: SymLoader => ltp.fromSource
case _ => false
}
if (pkgModule.isModule && !fromSource) {
// println("open "+pkgModule)//DEBUG
openPackageModule(pkgModule, pkgClass)
}
}
object perRunCaches {
import java.lang.ref.WeakReference
import scala.runtime.ScalaRunTime.stringOf
import scala.collection.generic.Clearable
// Weak references so the garbage collector will take care of
// letting us know when a cache is really out of commission.
private val caches = mutable.HashSet[WeakReference[Clearable]]()
def recordCache[T <: Clearable](cache: T): T = {
caches += new WeakReference(cache)
cache
}
def clearAll() = {
debuglog("Clearing " + caches.size + " caches.")
caches foreach { ref =>
val cache = ref.get()
if (cache == null)
caches -= ref
else
cache.clear()
}
}
def newWeakMap[K, V]() = recordCache(mutable.WeakHashMap[K, V]())
def newMap[K, V]() = recordCache(mutable.HashMap[K, V]())
def newSet[K]() = recordCache(mutable.HashSet[K]())
def newWeakSet[K <: AnyRef]() = recordCache(new WeakHashSet[K]())
}
/** The set of all installed infotransformers. */
var infoTransformers = new InfoTransformer {
val pid = NoPhase.id
val changesBaseClasses = true
def transform(sym: Symbol, tpe: Type): Type = tpe
}
/** The phase which has given index as identifier. */
val phaseWithId: Array[Phase]
/** Is this symbol table a part of a compiler universe?
*/
def isCompilerUniverse = false
}
object SymbolTableStats {
val phaseCounter = Statistics.newCounter("#phase calls")
}