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Compiler for the Scala Programming Language
/* NSC -- new Scala compiler
* Copyright 2005-2013 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package symtab
import java.io.IOException
import scala.compat.Platform.currentTime
import scala.tools.nsc.util.{ ClassPath }
import classfile.ClassfileParser
import scala.reflect.internal.Flags._
import scala.reflect.internal.MissingRequirementError
import scala.reflect.internal.util.Statistics
import scala.tools.nsc.io.{ AbstractFile, MsilFile }
/** This class ...
*
* @author Martin Odersky
* @version 1.0
*/
abstract class SymbolLoaders {
val global: Global
import global._
import SymbolLoadersStats._
protected def enterIfNew(owner: Symbol, member: Symbol, completer: SymbolLoader): Symbol = {
assert(owner.info.decls.lookup(member.name) == NoSymbol, owner.fullName + "." + member.name)
owner.info.decls enter member
member
}
/** Enter class with given `name` into scope of `root`
* and give them `completer` as type.
*/
def enterClass(owner: Symbol, name: String, completer: SymbolLoader): Symbol = {
val clazz = owner.newClass(newTypeName(name))
clazz setInfo completer
enterIfNew(owner, clazz, completer)
}
/** Enter module with given `name` into scope of `root`
* and give them `completer` as type.
*/
def enterModule(owner: Symbol, name: String, completer: SymbolLoader): Symbol = {
val module = owner.newModule(newTermName(name))
module setInfo completer
module.moduleClass setInfo moduleClassLoader
enterIfNew(owner, module, completer)
}
/** Enter package with given `name` into scope of `root`
* and give them `completer` as type.
*/
def enterPackage(root: Symbol, name: String, completer: SymbolLoader): Symbol = {
val pname = newTermName(name)
val preExisting = root.info.decls lookup pname
if (preExisting != NoSymbol) {
// Some jars (often, obfuscated ones) include a package and
// object with the same name. Rather than render them unusable,
// offer a setting to resolve the conflict one way or the other.
// This was motivated by the desire to use YourKit probes, which
// require yjp.jar at runtime. See SI-2089.
if (settings.termConflict.isDefault)
throw new TypeError(
root+" contains object and package with same name: "+
name+"\none of them needs to be removed from classpath"
)
else if (settings.termConflict.value == "package") {
global.warning(
"Resolving package/object name conflict in favor of package " +
preExisting.fullName + ". The object will be inaccessible."
)
root.info.decls.unlink(preExisting)
}
else {
global.warning(
"Resolving package/object name conflict in favor of object " +
preExisting.fullName + ". The package will be inaccessible."
)
return NoSymbol
}
}
// todo: find out initialization sequence for pkg/pkg.moduleClass is different from enterModule
val pkg = root.newPackage(pname)
pkg.moduleClass setInfo completer
pkg setInfo pkg.moduleClass.tpe
root.info.decls enter pkg
pkg
}
/** Enter class and module with given `name` into scope of `root`
* and give them `completer` as type.
*/
def enterClassAndModule(root: Symbol, name: String, completer: SymbolLoader) {
val clazz = enterClass(root, name, completer)
val module = enterModule(root, name, completer)
if (!clazz.isAnonymousClass) {
// Diagnostic for SI-7147
def msg: String = {
def symLocation(sym: Symbol) = if (sym == null) "null" else s"${clazz.fullLocationString} (from ${clazz.associatedFile})"
sm"""Inconsistent class/module symbol pair for `$name` loaded from ${symLocation(root)}.
|clazz = ${symLocation(clazz)}; clazz.companionModule = ${clazz.companionModule}
|module = ${symLocation(module)}; module.companionClass = ${module.companionClass}"""
}
assert(clazz.companionModule == module, msg)
assert(module.companionClass == clazz, msg)
}
}
/** In batch mode: Enter class and module with given `name` into scope of `root`
* and give them a source completer for given `src` as type.
* In IDE mode: Find all toplevel definitions in `src` and enter then into scope of `root`
* with source completer for given `src` as type.
* (overridden in interactive.Global).
*/
def enterToplevelsFromSource(root: Symbol, name: String, src: AbstractFile) {
enterClassAndModule(root, name, new SourcefileLoader(src))
}
/** The package objects of scala and scala.reflect should always
* be loaded in binary if classfiles are available, even if sourcefiles
* are newer. Late-compiling these objects from source leads to compilation
* order issues.
* Note: We do a name-base comparison here because the method is called before we even
* have ReflectPackage defined.
*/
def binaryOnly(owner: Symbol, name: String): Boolean =
name == "package" &&
(owner.fullName == "scala" || owner.fullName == "scala.reflect")
/** Initialize toplevel class and module symbols in `owner` from class path representation `classRep`
*/
def initializeFromClassPath(owner: Symbol, classRep: ClassPath[platform.BinaryRepr]#ClassRep) {
((classRep.binary, classRep.source) : @unchecked) match {
case (Some(bin), Some(src))
if platform.needCompile(bin, src) && !binaryOnly(owner, classRep.name) =>
if (settings.verbose.value) inform("[symloader] picked up newer source file for " + src.path)
global.loaders.enterToplevelsFromSource(owner, classRep.name, src)
case (None, Some(src)) =>
if (settings.verbose.value) inform("[symloader] no class, picked up source file for " + src.path)
global.loaders.enterToplevelsFromSource(owner, classRep.name, src)
case (Some(bin), _) =>
global.loaders.enterClassAndModule(owner, classRep.name, platform.newClassLoader(bin))
}
}
/**
* A lazy type that completes itself by calling parameter doComplete.
* Any linked modules/classes or module classes are also initialized.
* Todo: consider factoring out behavior from TopClassCompleter/SymbolLoader into
* supertrait SymLoader
*/
abstract class SymbolLoader extends SymLoader {
/** Load source or class file for `root`, return */
protected def doComplete(root: Symbol): Unit
def sourcefile: Option[AbstractFile] = None
/**
* Description of the resource (ClassPath, AbstractFile, MsilFile)
* being processed by this loader
*/
protected def description: String
private var ok = false
private def setSource(sym: Symbol) {
sourcefile foreach (sf => sym match {
case cls: ClassSymbol => cls.sourceFile = sf
case mod: ModuleSymbol => mod.moduleClass.sourceFile = sf
case _ => ()
})
}
override def complete(root: Symbol) {
def signalError(ex: Exception) {
ok = false
if (settings.debug.value) ex.printStackTrace()
val msg = ex.getMessage()
// SI-5593 Scaladoc's current strategy is to visit all packages in search of user code that can be documented
// therefore, it will rummage through the classpath triggering errors whenever it encounters package objects
// that are not in their correct place (see bug for details)
if (!settings.isScaladoc)
globalError(
if (msg eq null) "i/o error while loading " + root.name
else "error while loading " + root.name + ", " + msg);
}
try {
val start = currentTime
val currentphase = phase
doComplete(root)
phase = currentphase
informTime("loaded " + description, start)
ok = true
setSource(root)
setSource(root.companionSymbol) // module -> class, class -> module
} catch {
case ex: IOException =>
signalError(ex)
case ex: MissingRequirementError =>
signalError(ex)
}
initRoot(root)
if (!root.isPackageClass) initRoot(root.companionSymbol)
}
override def load(root: Symbol) { complete(root) }
private def markAbsent(sym: Symbol): Unit = {
val tpe: Type = if (ok) NoType else ErrorType
if (sym != NoSymbol)
sym setInfo tpe
}
private def initRoot(root: Symbol) {
if (root.rawInfo == this)
List(root, root.moduleClass) foreach markAbsent
else if (root.isClass && !root.isModuleClass)
root.rawInfo.load(root)
}
}
/**
* Load contents of a package
*/
class PackageLoader(classpath: ClassPath[platform.BinaryRepr]) extends SymbolLoader with FlagAgnosticCompleter {
protected def description = "package loader "+ classpath.name
protected def doComplete(root: Symbol) {
assert(root.isPackageClass, root)
root.setInfo(new PackageClassInfoType(newScope, root))
val sourcepaths = classpath.sourcepaths
if (!root.isRoot) {
for (classRep <- classpath.classes if platform.doLoad(classRep)) {
initializeFromClassPath(root, classRep)
}
}
if (!root.isEmptyPackageClass) {
for (pkg <- classpath.packages) {
enterPackage(root, pkg.name, new PackageLoader(pkg))
}
openPackageModule(root)
}
}
}
class ClassfileLoader(val classfile: AbstractFile) extends SymbolLoader with FlagAssigningCompleter {
private object classfileParser extends ClassfileParser {
val global: SymbolLoaders.this.global.type = SymbolLoaders.this.global
}
protected def description = "class file "+ classfile.toString
protected def doComplete(root: Symbol) {
val start = if (Statistics.canEnable) Statistics.startTimer(classReadNanos) else null
classfileParser.parse(classfile, root)
if (root.associatedFile eq null) {
root match {
// In fact, the ModuleSymbol forwards its setter to the module class
case _: ClassSymbol | _: ModuleSymbol =>
debuglog("ClassfileLoader setting %s.associatedFile = %s".format(root.name, classfile))
root.associatedFile = classfile
case _ =>
debuglog("Not setting associatedFile to %s because %s is a %s".format(classfile, root.name, root.shortSymbolClass))
}
}
if (Statistics.canEnable) Statistics.stopTimer(classReadNanos, start)
}
override def sourcefile: Option[AbstractFile] = classfileParser.srcfile
}
class MsilFileLoader(msilFile: MsilFile) extends SymbolLoader with FlagAssigningCompleter {
private def typ = msilFile.msilType
private object typeParser extends clr.TypeParser {
val global: SymbolLoaders.this.global.type = SymbolLoaders.this.global
}
protected def description = "MsilFile "+ typ.FullName + ", assembly "+ typ.Assembly.FullName
protected def doComplete(root: Symbol) { typeParser.parse(typ, root) }
}
class SourcefileLoader(val srcfile: AbstractFile) extends SymbolLoader with FlagAssigningCompleter {
protected def description = "source file "+ srcfile.toString
override def fromSource = true
override def sourcefile = Some(srcfile)
protected def doComplete(root: Symbol): Unit = global.currentRun.compileLate(srcfile)
}
object moduleClassLoader extends SymbolLoader with FlagAssigningCompleter {
protected def description = "module class loader"
protected def doComplete(root: Symbol) { root.sourceModule.initialize }
}
object clrTypes extends clr.CLRTypes {
val global: SymbolLoaders.this.global.type = SymbolLoaders.this.global
if (global.forMSIL) init()
}
/** used from classfile parser to avoid cyclies */
var parentsLevel = 0
var pendingLoadActions: List[() => Unit] = Nil
}
object SymbolLoadersStats {
import scala.reflect.internal.TypesStats.typerNanos
val classReadNanos = Statistics.newSubTimer ("time classfilereading", typerNanos)
}