/* NSC -- new Scala compiler
* Copyright 2009-2013 Typesafe/Scala Solutions and LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package interactive
import scala.util.control.ControlThrowable
import scala.tools.nsc.io.AbstractFile
import scala.tools.nsc.util.FailedInterrupt
import scala.tools.nsc.util.EmptyAction
import scala.tools.nsc.util.WorkScheduler
import scala.reflect.internal.util.{SourceFile, Position}
import scala.tools.nsc.util.InterruptReq
/** Interface of interactive compiler to a client such as an IDE
* The model the presentation compiler consists of the following parts:
*
* unitOfFile: The map from sourcefiles to loaded units. A sourcefile/unit is loaded if it occurs in that map.
*
* manipulated by: removeUnitOf, reloadSources.
*
* A call to reloadSources will add the given sources to the loaded units, and
* start a new background compiler pass to compile all loaded units (with the indicated sources first).
* Each background compiler pass has its own typer run.
* The background compiler thread can be interrupted each time an AST node is
* completely typechecked in the following ways:
* 1. by a new call to reloadSources. This starts a new background compiler pass with a new typer run.
* 2. by a call to askTypeTree. This starts a new typer run if the forceReload parameter = true
* 3. by a call to askTypeAt, askTypeCompletion, askScopeCompletion, askToDoFirst, askLinkPos, askLastType.
* 4. by raising an exception in the scheduler.
* 5. by passing a high-priority action wrapped in ask { ... }.
*
* Actions under 1-3 can themselves be interrupted if they involve typechecking
* AST nodes. High-priority actions under 5 cannot; they always run to completion.
* So these high-priority actions should to be short.
*
* Normally, an interrupted action continues after the interrupting action is finished.
* However, if the interrupting action created a new typer run, the interrupted
* action is aborted. If there's an outstanding response, it will be set to
* a Right value with a FreshRunReq exception.
*/
trait CompilerControl { self: Global =>
type Response[T] = scala.tools.nsc.interactive.Response[T]
/** The scheduler by which client and compiler communicate
* Must be initialized before starting compilerRunner
*/
@volatile protected[interactive] var scheduler = new WorkScheduler
/** Return the compilation unit attached to a source file, or None
* if source is not loaded.
*/
def getUnitOf(s: SourceFile): Option[RichCompilationUnit] = getUnit(s)
/** Run operation `op` on a compilation unit associated with given `source`.
* If source has a loaded compilation unit, this one is passed to `op`.
* Otherwise a new compilation unit is created, but not added to the set of loaded units.
*/
def onUnitOf[T](source: SourceFile)(op: RichCompilationUnit => T): T =
op(unitOfFile.getOrElse(source.file, new RichCompilationUnit(source)))
/** Removes the CompilationUnit corresponding to the given SourceFile
* from consideration for recompilation.
*/
def removeUnitOf(s: SourceFile): Option[RichCompilationUnit] = { toBeRemoved += s.file; unitOfFile get s.file }
/** Returns the top level classes and objects that were deleted
* in the editor since last time recentlyDeleted() was called.
*/
def recentlyDeleted(): List[Symbol] = deletedTopLevelSyms.synchronized {
val result = deletedTopLevelSyms
deletedTopLevelSyms.clear()
result.toList
}
/** Locate smallest tree that encloses position
* @pre Position must be loaded
*/
def locateTree(pos: Position): Tree = onUnitOf(pos.source) { unit => new Locator(pos) locateIn unit.body }
/** Locates smallest context that encloses position as an optional value.
*/
def locateContext(pos: Position): Option[Context] =
for (unit <- getUnit(pos.source); cx <- locateContext(unit.contexts, pos)) yield cx
/** Returns the smallest context that contains given `pos`, throws FatalError if none exists.
*/
def doLocateContext(pos: Position): Context = locateContext(pos) getOrElse {
throw new FatalError("no context found for "+pos)
}
private def postWorkItem(item: WorkItem) =
if (item.onCompilerThread) item() else scheduler.postWorkItem(item)
/** Makes sure a set of compilation units is loaded and parsed.
* Returns () to syncvar `response` on completion.
* Afterwards a new background compiler run is started with
* the given sources at the head of the list of to-be-compiled sources.
*/
def askReload(sources: List[SourceFile], response: Response[Unit]) = {
val superseeded = scheduler.dequeueAll {
case ri: ReloadItem if ri.sources == sources => Some(ri)
case _ => None
}
superseeded.foreach(_.response.set(()))
postWorkItem(new ReloadItem(sources, response))
}
/** Removes source files and toplevel symbols, and issues a new typer run.
* Returns () to syncvar `response` on completion.
*/
def askFilesDeleted(sources: List[SourceFile], response: Response[Unit]) = {
postWorkItem(new FilesDeletedItem(sources, response))
}
/** Sets sync var `response` to the smallest fully attributed tree that encloses position `pos`.
* Note: Unlike for most other ask... operations, the source file belonging to `pos` needs not be loaded.
*/
def askTypeAt(pos: Position, response: Response[Tree]) =
postWorkItem(new AskTypeAtItem(pos, response))
/** Sets sync var `response` to the fully attributed & typechecked tree contained in `source`.
* @pre `source` needs to be loaded.
* @note Deprecated because of race conditions in the typechecker when the background compiler
* is interrupted while typing the same `source`.
* @see SI-6578
*/
@deprecated("Use `askLoadedTyped` instead to avoid race conditions in the typechecker", "2.10.1")
def askType(source: SourceFile, forceReload: Boolean, response: Response[Tree]) =
postWorkItem(new AskTypeItem(source, forceReload, response))
/** Sets sync var `response` to the position of the definition of the given link in
* the given sourcefile.
*
* @param sym The symbol referenced by the link (might come from a classfile)
* @param source The source file that's supposed to contain the definition
* @param response A response that will be set to the following:
* If `source` contains a definition that is referenced by the given link
* the position of that definition, otherwise NoPosition.
* Note: This operation does not automatically load `source`. If `source`
* is unloaded, it stays that way.
*/
def askLinkPos(sym: Symbol, source: SourceFile, response: Response[Position]) =
postWorkItem(new AskLinkPosItem(sym, source, response))
/** Sets sync var `response` to doc comment information for a given symbol.
*
* @param sym The symbol whose doc comment should be retrieved (might come from a classfile)
* @param source The source file that's supposed to contain the definition
* @param site The symbol where 'sym' is observed
* @param fragments All symbols that can contribute to the generated documentation
* together with their source files.
* @param response A response that will be set to the following:
* If `source` contains a definition of a given symbol that has a doc comment,
* the (expanded, raw, position) triplet for a comment, otherwise ("", "", NoPosition).
* Note: This operation does not automatically load sources that are not yet loaded.
*/
def askDocComment(sym: Symbol, source: SourceFile, site: Symbol, fragments: List[(Symbol,SourceFile)], response: Response[(String, String, Position)]): Unit =
postWorkItem(new AskDocCommentItem(sym, source, site, fragments, response))
@deprecated("Use method that accepts fragments", "2.10.2")
def askDocComment(sym: Symbol, site: Symbol, source: SourceFile, response: Response[(String, String, Position)]): Unit =
askDocComment(sym, source, site, (sym,source)::Nil, response)
/** Sets sync var `response` to list of members that are visible
* as members of the tree enclosing `pos`, possibly reachable by an implicit.
* @pre source is loaded
*/
def askTypeCompletion(pos: Position, response: Response[List[Member]]) =
postWorkItem(new AskTypeCompletionItem(pos, response))
/** Sets sync var `response` to list of members that are visible
* as members of the scope enclosing `pos`.
* @pre source is loaded
*/
def askScopeCompletion(pos: Position, response: Response[List[Member]]) =
postWorkItem(new AskScopeCompletionItem(pos, response))
/** Asks to do unit corresponding to given source file on present and subsequent type checking passes.
* If the file is in the 'crashedFiles' ignore list it is removed and typechecked normally.
*/
def askToDoFirst(source: SourceFile) =
postWorkItem(new AskToDoFirstItem(source))
/** If source is not yet loaded, loads it, and starts a new run, otherwise
* continues with current pass.
* Waits until source is fully type checked and returns body in response.
* @param source The source file that needs to be fully typed.
* @param keepLoaded Whether to keep that file in the PC if it was not loaded before. If
the file is already loaded, this flag is ignored.
* @param response The response, which is set to the fully attributed tree of `source`.
* If the unit corresponding to `source` has been removed in the meantime
* the a NoSuchUnitError is raised in the response.
*/
def askLoadedTyped(source:SourceFile, keepLoaded: Boolean, response: Response[Tree]): Unit =
postWorkItem(new AskLoadedTypedItem(source, keepLoaded, response))
final def askLoadedTyped(source: SourceFile, response: Response[Tree]): Unit =
askLoadedTyped(source, false, response)
/** If source if not yet loaded, get an outline view with askParseEntered.
* If source is loaded, wait for it to be typechecked.
* In both cases, set response to parsed (and possibly typechecked) tree.
* @param keepSrcLoaded If set to `true`, source file will be kept as a loaded unit afterwards.
*/
def askStructure(keepSrcLoaded: Boolean)(source: SourceFile, response: Response[Tree]) = {
getUnit(source) match {
case Some(_) => askLoadedTyped(source, keepSrcLoaded, response)
case None => askParsedEntered(source, keepSrcLoaded, response)
}
}
/** Set sync var `response` to the parse tree of `source` with all top-level symbols entered.
* @param source The source file to be analyzed
* @param keepLoaded If set to `true`, source file will be kept as a loaded unit afterwards.
* If keepLoaded is `false` the operation is run at low priority, only after
* everything is brought up to date in a regular type checker run.
* @param response The response.
*/
def askParsedEntered(source: SourceFile, keepLoaded: Boolean, response: Response[Tree]) =
postWorkItem(new AskParsedEnteredItem(source, keepLoaded, response))
/** Cancels current compiler run and start a fresh one where everything will be re-typechecked
* (but not re-loaded).
*/
def askReset() = scheduler raise (new FreshRunReq)
/** Tells the compile server to shutdown, and not to restart again */
def askShutdown() = scheduler raise ShutdownReq
/** Returns parse tree for source `source`. No symbols are entered. Syntax errors are reported.
*
* This method is thread-safe and as such can safely run outside of the presentation
* compiler thread.
*/
def parseTree(source: SourceFile): Tree = {
newUnitParser(new CompilationUnit(source)).parse()
}
/** Asks for a computation to be done quickly on the presentation compiler thread */
def ask[A](op: () => A): A = if (self.onCompilerThread) op() else scheduler doQuickly op
/** Asks for a computation to be done on presentation compiler thread, returning
* a response with the result or an exception
*/
def askForResponse[A](op: () => A): Response[A] = {
val r = new Response[A]
if (self.onCompilerThread) {
try { r set op() }
catch { case exc: Throwable => r raise exc }
r
} else {
val ir = scheduler askDoQuickly op
ir onComplete {
case Left(result) => r set result
case Right(exc) => r raise exc
}
r
}
}
def onCompilerThread = Thread.currentThread == compileRunner
/** Info given for every member found by completion
*/
abstract class Member {
def prefix: Type
val sym: Symbol
val tpe: Type
val accessible: Boolean
def implicitlyAdded = false
def symNameDropLocal: Name = sym.name.dropLocal
private def accessible_s = if (accessible) "" else "[inaccessible] "
def forceInfoString = {
definitions.fullyInitializeSymbol(sym)
definitions.fullyInitializeType(tpe)
infoString
}
def infoString = s"$accessible_s${sym.defStringSeenAs(tpe)}"
}
case class TypeMember(
sym: Symbol,
tpe: Type,
accessible: Boolean,
inherited: Boolean,
viaView: Symbol) extends Member {
// should be a case class parameter, but added as a var instead to preserve compatibility with the IDE
var prefix: Type = NoType
override def implicitlyAdded = viaView != NoSymbol
}
case class ScopeMember(
sym: Symbol,
tpe: Type,
accessible: Boolean,
viaImport: Tree) extends Member {
// should be a case class parameter, but added as a var instead to preserve compatibility with the IDE
var prefix: Type = NoType
}
// items that get sent to scheduler
abstract class WorkItem extends (() => Unit) {
val onCompilerThread = self.onCompilerThread
/** Raise a MissingResponse, if the work item carries a response. */
def raiseMissing(): Unit
}
case class ReloadItem(sources: List[SourceFile], response: Response[Unit]) extends WorkItem {
def apply() = reload(sources, response)
override def toString = "reload "+sources
def raiseMissing() =
response raise new MissingResponse
}
case class FilesDeletedItem(sources: List[SourceFile], response: Response[Unit]) extends WorkItem {
def apply() = filesDeleted(sources, response)
override def toString = "files deleted "+sources
def raiseMissing() =
response raise new MissingResponse
}
case class AskTypeAtItem(pos: Position, response: Response[Tree]) extends WorkItem {
def apply() = self.getTypedTreeAt(pos, response)
override def toString = "typeat "+pos.source+" "+pos.show
def raiseMissing() =
response raise new MissingResponse
}
case class AskTypeItem(source: SourceFile, forceReload: Boolean, response: Response[Tree]) extends WorkItem {
def apply() = self.getTypedTree(source, forceReload, response)
override def toString = "typecheck"
def raiseMissing() =
response raise new MissingResponse
}
case class AskTypeCompletionItem(pos: Position, response: Response[List[Member]]) extends WorkItem {
def apply() = self.getTypeCompletion(pos, response)
override def toString = "type completion "+pos.source+" "+pos.show
def raiseMissing() =
response raise new MissingResponse
}
case class AskScopeCompletionItem(pos: Position, response: Response[List[Member]]) extends WorkItem {
def apply() = self.getScopeCompletion(pos, response)
override def toString = "scope completion "+pos.source+" "+pos.show
def raiseMissing() =
response raise new MissingResponse
}
class AskToDoFirstItem(val source: SourceFile) extends WorkItem {
def apply() = {
moveToFront(List(source))
enableIgnoredFile(source.file)
}
override def toString = "dofirst "+source
def raiseMissing() = ()
}
case class AskLinkPosItem(sym: Symbol, source: SourceFile, response: Response[Position]) extends WorkItem {
def apply() = self.getLinkPos(sym, source, response)
override def toString = "linkpos "+sym+" in "+source
def raiseMissing() =
response raise new MissingResponse
}
case class AskDocCommentItem(sym: Symbol, source: SourceFile, site: Symbol, fragments: List[(Symbol,SourceFile)], response: Response[(String, String, Position)]) extends WorkItem {
def apply() = self.getDocComment(sym, source, site, fragments, response)
override def toString = "doc comment "+sym+" in "+source+" with fragments:"+fragments.mkString("(", ",", ")")
def raiseMissing() =
response raise new MissingResponse
}
case class AskLoadedTypedItem(source: SourceFile, keepLoaded: Boolean, response: Response[Tree]) extends WorkItem {
def apply() = self.waitLoadedTyped(source, response, keepLoaded, this.onCompilerThread)
override def toString = "wait loaded & typed "+source
def raiseMissing() =
response raise new MissingResponse
}
case class AskParsedEnteredItem(source: SourceFile, keepLoaded: Boolean, response: Response[Tree]) extends WorkItem {
def apply() = self.getParsedEntered(source, keepLoaded, response, this.onCompilerThread)
override def toString = "getParsedEntered "+source+", keepLoaded = "+keepLoaded
def raiseMissing() =
response raise new MissingResponse
}
/** A do-nothing work scheduler that responds immediately with MissingResponse.
*
* Used during compiler shutdown.
*/
class NoWorkScheduler extends WorkScheduler {
override def postWorkItem(action: Action) = synchronized {
action match {
case w: WorkItem => w.raiseMissing()
case e: EmptyAction => // do nothing
case _ => println("don't know what to do with this " + action.getClass)
}
}
override def doQuickly[A](op: () => A): A = {
throw new FailedInterrupt(new Exception("Posted a work item to a compiler that's shutting down"))
}
override def askDoQuickly[A](op: () => A): InterruptReq { type R = A } = {
val ir = new InterruptReq {
type R = A
val todo = () => throw new MissingResponse
}
ir.execute()
ir
}
}
}
// ---------------- Interpreted exceptions -------------------
/** Signals a request for a fresh background compiler run.
* Note: The object has to stay top-level so that the PresentationCompilerThread may access it.
*/
class FreshRunReq extends ControlThrowable
/** Signals a request for a shutdown of the presentation compiler.
* Note: The object has to stay top-level so that the PresentationCompilerThread may access it.
*/
object ShutdownReq extends ControlThrowable
class NoSuchUnitError(file: AbstractFile) extends Exception("no unit found for file "+file)
class MissingResponse extends Exception("response missing")
