diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala | 311 |
1 files changed, 224 insertions, 87 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala index 64638ca34d..b9f593a4d8 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala @@ -25,49 +25,110 @@ class Inliner[BT <: BTypes](val btypes: BT) { import inlinerHeuristics._ import backendUtils._ - case class InlineLog(request: InlineRequest, sizeBefore: Int, sizeAfter: Int, sizeInlined: Int, warning: Option[CannotInlineWarning]) - var inlineLog: List[InlineLog] = Nil + sealed trait InlineLog { + def request: InlineRequest + } + final case class InlineLogSuccess(request: InlineRequest, sizeBefore: Int, sizeInlined: Int) extends InlineLog { + var downstreamLog: mutable.Buffer[InlineLog] = mutable.ListBuffer.empty + } + final case class InlineLogFail(request: InlineRequest, warning: CannotInlineWarning) extends InlineLog + final case class InlineLogRollback(request: InlineRequest, warnings: List[CannotInlineWarning]) extends InlineLog + + object InlineLog { + private def shouldLog(request: InlineRequest): Boolean = { + def logEnabled = compilerSettings.YoptLogInline.isSetByUser + def matchesName = { + val prefix = compilerSettings.YoptLogInline.value match { + case "_" => "" + case p => p + } + val name: String = request.callsite.callsiteClass.internalName + "." + request.callsite.callsiteMethod.name + name startsWith prefix + } + logEnabled && (upstream != null || (isTopLevel && matchesName)) + } - def runInliner(): Unit = { - for (request <- collectAndOrderInlineRequests) { - val Right(callee) = request.callsite.callee // collectAndOrderInlineRequests returns callsites with a known callee + // indexed by callsite method + private val logs = mutable.Map.empty[MethodNode, mutable.LinkedHashSet[InlineLog]] - // TODO: if the request has downstream requests, create a snapshot to which we could roll back in case some downstream callsite cannot be inlined - // (Needs to revert modifications to the callee method, but also the call graph) - // (This assumes that inlining a request only makes sense if its downstream requests are satisfied - sync with heuristics!) + private var upstream: InlineLogSuccess = _ + private var isTopLevel = true - val warnings = inline(request) - for (warning <- warnings) { - if ((callee.annotatedInline && btypes.compilerSettings.optWarningEmitAtInlineFailed) || warning.emitWarning(compilerSettings)) { - val annotWarn = if (callee.annotatedInline) " is annotated @inline but" else "" - val msg = s"${BackendReporting.methodSignature(callee.calleeDeclarationClass.internalName, callee.callee)}$annotWarn could not be inlined:\n$warning" - backendReporting.inlinerWarning(request.callsite.callsitePosition, msg) - } + def withInlineLogging[T](request: InlineRequest)(inlineRequest: => Unit)(inlinePost: => T): T = { + def doInlinePost(): T = { + val savedIsTopLevel = isTopLevel + isTopLevel = false + try inlinePost + finally isTopLevel = savedIsTopLevel + } + if (shouldLog(request)) { + val sizeBefore = request.callsite.callsiteMethod.instructions.size + inlineRequest + val log = InlineLogSuccess(request, sizeBefore, request.callsite.callee.get.callee.instructions.size) + apply(log) + + val savedUpstream = upstream + upstream = log + try doInlinePost() + finally upstream = savedUpstream + } else { + inlineRequest + doInlinePost() } } - if (compilerSettings.YoptLogInline.isSetByUser) { - val methodPrefix = { val p = compilerSettings.YoptLogInline.value; if (p == "_") "" else p } - val byCallsiteMethod = inlineLog.groupBy(_.request.callsite.callsiteMethod).toList.sortBy(_._2.head.request.callsite.callsiteClass.internalName) - for ((m, mLogs) <- byCallsiteMethod) { - val initialSize = mLogs.minBy(_.sizeBefore).sizeBefore - val firstLog = mLogs.head - val methodName = s"${firstLog.request.callsite.callsiteClass.internalName}.${m.name}" - if (methodName.startsWith(methodPrefix)) { - println(s"Inlining into $methodName (initially $initialSize instructions, ultimately ${m.instructions.size}):") - val byCallee = mLogs.groupBy(_.request.callsite.callee.get).toList.sortBy(_._2.length).reverse - for ((c, cLogs) <- byCallee) { - val first = cLogs.head - if (first.warning.isEmpty) { - val num = if (cLogs.tail.isEmpty) "" else s" ${cLogs.length} times" - println(s" - Inlined ${c.calleeDeclarationClass.internalName}.${c.callee.name} (${first.sizeInlined} instructions)$num: ${first.request.reason}") - } else - println(s" - Failed to inline ${c.calleeDeclarationClass.internalName}.${c.callee.name} (${first.request.reason}): ${first.warning.get}") - } - println() - } + def apply(log: => InlineLog): Unit = if (shouldLog(log.request)) { + if (upstream != null) upstream.downstreamLog += log + else { + val methodLogs = logs.getOrElseUpdate(log.request.callsite.callsiteMethod, mutable.LinkedHashSet.empty) + methodLogs += log + } + } + + def entryString(log: InlineLog, indent: Int = 0): String = { + val callee = log.request.callsite.callee.get + val calleeString = callee.calleeDeclarationClass.internalName + "." + callee.callee.name + val indentString = " " * indent + log match { + case s @ InlineLogSuccess(_, sizeBefore, sizeInlined) => + val self = s"${indentString}inlined $calleeString. Before: $sizeBefore ins, inlined: $sizeInlined ins." + if (s.downstreamLog.isEmpty) self + else s.downstreamLog.iterator.map(entryString(_, indent + 2)).mkString(self + "\n", "\n", "") + + case InlineLogFail(_, w) => + s"${indentString}failed $calleeString. ${w.toString.replace('\n', ' ')}" + + case InlineLogRollback(_, _) => + s"${indentString}rolling back, nested inline failed." + } + } + + def print(): Unit = if (compilerSettings.YoptLogInline.isSetByUser) { + val byClassAndMethod: List[(InternalName, mutable.Map[MethodNode, mutable.LinkedHashSet[InlineLog]])] = { + logs. + groupBy(_._2.head.request.callsite.callsiteClass.internalName). + toList.sortBy(_._1) + } + for { + (c, methodLogs) <- byClassAndMethod + (m, mLogs) <- methodLogs.toList.sortBy(_._1.name) + mLog <- mLogs // insertion order + } { + println(s"Inline into $c.${m.name}: ${entryString(mLog)}") + } + } + } + + def runInliner(): Unit = { + for (request <- collectAndOrderInlineRequests) { + val Right(callee) = request.callsite.callee // collectAndOrderInlineRequests returns callsites with a known callee + val warnings = inline(request) + for (warning <- warnings) { + if (warning.emitWarning(compilerSettings)) + backendReporting.inlinerWarning(request.callsite.callsitePosition, warning.toString) } } + InlineLog.print() } /** @@ -221,26 +282,79 @@ class Inliner[BT <: BTypes](val btypes: BT) { impl(post, mainCallsite) } + class UndoLog(active: Boolean = true) { + import java.util.{ ArrayList => JArrayList } + + private var actions = List.empty[() => Unit] + private var methodStateSaved = false + + def apply(a: => Unit): Unit = if (active) actions = (() => a) :: actions + def rollback(): Unit = if (active) actions.foreach(_.apply()) + + def saveMethodState(methodNode: MethodNode): Unit = if (active && !methodStateSaved) { + methodStateSaved = true + val currentInstructions = methodNode.instructions.toArray + val currentLocalVariables = new JArrayList(methodNode.localVariables) + val currentTryCatchBlocks = new JArrayList(methodNode.tryCatchBlocks) + val currentMaxLocals = methodNode.maxLocals + val currentMaxStack = methodNode.maxStack + + apply { + // `methodNode.instructions.clear()` doesn't work: it keeps the `prev` / `next` / `index` of + // instruction nodes. `instructions.removeAll(true)` would work, but is not public. + methodNode.instructions.iterator.asScala.toList.foreach(methodNode.instructions.remove) + for (i <- currentInstructions) methodNode.instructions.add(i) + + methodNode.localVariables.clear() + methodNode.localVariables.addAll(currentLocalVariables) + + methodNode.tryCatchBlocks.clear() + methodNode.tryCatchBlocks.addAll(currentTryCatchBlocks) + + methodNode.maxLocals = currentMaxLocals + methodNode.maxStack = currentMaxStack + } + } + } + + val NoUndoLogging = new UndoLog(active = false) /** * Inline the callsite of an inlining request and its post-inlining requests. * * @return An inliner warning for each callsite that could not be inlined. */ - def inline(request: InlineRequest): List[CannotInlineWarning] = canInlineBody(request.callsite) match { - case Some(w) => - if (compilerSettings.YoptLogInline.isSetByUser) { - val size = request.callsite.callsiteMethod.instructions.size - inlineLog ::= InlineLog(request, size, size, 0, Some(w)) + def inline(request: InlineRequest, undo: UndoLog = NoUndoLogging): List[CannotInlineWarning] = { + def doInline(undo: UndoLog, callRollback: Boolean = false): List[CannotInlineWarning] = { + InlineLog.withInlineLogging(request) { + inlineCallsite(request.callsite, undo) + } { + val postRequests = request.post.flatMap(adaptPostRequestForMainCallsite(_, request.callsite)) + val warnings = postRequests.flatMap(inline(_, undo)) + if (callRollback && warnings.nonEmpty) { + undo.rollback() + InlineLog(InlineLogRollback(request, warnings)) + } + warnings } - List(w) - case None => - val sizeBefore = request.callsite.callsiteMethod.instructions.size - inlineCallsite(request.callsite) - if (compilerSettings.YoptLogInline.isSetByUser) - inlineLog ::= InlineLog(request, sizeBefore, request.callsite.callsiteMethod.instructions.size, request.callsite.callee.get.callee.instructions.size, None) - val postRequests = request.post.flatMap(adaptPostRequestForMainCallsite(_, request.callsite)) - postRequests flatMap inline + } + + def inlinedByPost(insns: List[AbstractInsnNode]): Boolean = + insns.nonEmpty && insns.forall(ins => request.post.exists(_.callsite.callsiteInstruction == ins)) + + canInlineCallsite(request.callsite) match { + case None => + doInline(undo) + + case Some((_, illegalAccessInsns)) if inlinedByPost(illegalAccessInsns) => + // speculatively inline, roll back if an illegalAccessInsn cannot be eliminated + if (undo == NoUndoLogging) doInline(new UndoLog(), callRollback = true) + else doInline(undo) + + case Some((w, _)) => + InlineLog(InlineLogFail(request, w)) + List(w) + } } /** @@ -253,7 +367,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { * @return A map associating instruction nodes of the callee with the corresponding cloned * instruction in the callsite method. */ - def inlineCallsite(callsite: Callsite): Unit = { + def inlineCallsite(callsite: Callsite, undo: UndoLog = NoUndoLogging): Unit = { import callsite.{callsiteClass, callsiteMethod, callsiteInstruction, receiverKnownNotNull, callsiteStackHeight} val Right(callsiteCallee) = callsite.callee import callsiteCallee.{callee, calleeDeclarationClass, sourceFilePath} @@ -380,6 +494,8 @@ class Inliner[BT <: BTypes](val btypes: BT) { clonedInstructions.insert(postCallLabel, retVarLoad) } + undo.saveMethodState(callsiteMethod) + callsiteMethod.instructions.insert(callsiteInstruction, clonedInstructions) callsiteMethod.instructions.remove(callsiteInstruction) @@ -406,7 +522,8 @@ class Inliner[BT <: BTypes](val btypes: BT) { callsiteMethod.maxStack = math.max(callsiteMethod.maxStack, math.max(stackHeightAtNullCheck, maxStackOfInlinedCode)) - addIndyLambdaImplMethod(callsiteClass.internalName, targetHandles) + val added = addIndyLambdaImplMethod(callsiteClass.internalName, targetHandles) + undo { removeIndyLambdaImplMethod(callsiteClass.internalName, added) } callGraph.addIfMissing(callee, calleeDeclarationClass) @@ -426,8 +543,13 @@ class Inliner[BT <: BTypes](val btypes: BT) { argInfos = argInfos, callsiteStackHeight = callsiteStackHeight + originalCallsite.callsiteStackHeight ) - originalCallsite.inlinedClones += ClonedCallsite(newCallsite, callsite) + val clonedCallsite = ClonedCallsite(newCallsite, callsite) + originalCallsite.inlinedClones += clonedCallsite callGraph.addCallsite(newCallsite) + undo { + originalCallsite.inlinedClones -= clonedCallsite + callGraph.removeCallsite(newCallsite.callsiteInstruction, newCallsite.callsiteMethod) + } } callGraph.closureInstantiations(callee).valuesIterator foreach { originalClosureInit => @@ -440,10 +562,14 @@ class Inliner[BT <: BTypes](val btypes: BT) { capturedArgInfos) originalClosureInit.inlinedClones += newClosureInit callGraph.addClosureInstantiation(newClosureInit) + undo { + callGraph.removeClosureInstantiation(newClosureInit.lambdaMetaFactoryCall.indy, newClosureInit.ownerMethod) + } } // Remove the elided invocation from the call graph callGraph.removeCallsite(callsiteInstruction, callsiteMethod) + undo { callGraph.addCallsite(callsite) } // Inlining a method body can render some code unreachable, see example above in this method. unreachableCodeEliminated -= callsiteMethod @@ -467,10 +593,10 @@ class Inliner[BT <: BTypes](val btypes: BT) { if (isSynchronizedMethod(callee)) { // Could be done by locking on the receiver, wrapping the inlined code in a try and unlocking // in finally. But it's probably not worth the effort, scala never emits synchronized methods. - Some(SynchronizedMethod(calleeDeclarationClass.internalName, callee.name, callee.desc)) + Some(SynchronizedMethod(calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated)) } else if (isStrictfpMethod(callsiteMethod) != isStrictfpMethod(callee)) { Some(StrictfpMismatch( - calleeDeclarationClass.internalName, callee.name, callee.desc, + calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated, callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc)) } else None @@ -486,9 +612,14 @@ class Inliner[BT <: BTypes](val btypes: BT) { * we don't query it while traversing the call graph and selecting callsites to inline - it might * rule out callsites that can be inlined just fine. * - * @return `Some(message)` if inlining cannot be performed, `None` otherwise + * Returns + * - `None` if the callsite can be inlined + * - `Some((message, Nil))` if there was an issue performing the access checks, for example + * because of a missing classfile + * - `Some((message, instructions))` if inlining `instructions` into the callsite method would + * cause an IllegalAccessError */ - def canInlineBody(callsite: Callsite): Option[CannotInlineWarning] = { + def canInlineCallsite(callsite: Callsite): Option[(CannotInlineWarning, List[AbstractInsnNode])] = { import callsite.{callsiteInstruction, callsiteMethod, callsiteClass, callsiteStackHeight} val Right(callsiteCallee) = callsite.callee import callsiteCallee.{callee, calleeDeclarationClass} @@ -519,23 +650,30 @@ class Inliner[BT <: BTypes](val btypes: BT) { } if (codeSizeOKForInlining(callsiteMethod, callee)) { - Some(ResultingMethodTooLarge( - calleeDeclarationClass.internalName, callee.name, callee.desc, - callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc)) + val warning = ResultingMethodTooLarge( + calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated, + callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc) + Some((warning, Nil)) } else if (!callee.tryCatchBlocks.isEmpty && stackHasNonParameters) { - Some(MethodWithHandlerCalledOnNonEmptyStack( - calleeDeclarationClass.internalName, callee.name, callee.desc, - callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc)) - } else findIllegalAccess(callee.instructions, calleeDeclarationClass, callsiteClass) map { - case (illegalAccessIns, None) => - IllegalAccessInstruction( - calleeDeclarationClass.internalName, callee.name, callee.desc, - callsiteClass.internalName, illegalAccessIns) - - case (illegalAccessIns, Some(warning)) => - IllegalAccessCheckFailed( - calleeDeclarationClass.internalName, callee.name, callee.desc, - callsiteClass.internalName, illegalAccessIns, warning) + val warning = MethodWithHandlerCalledOnNonEmptyStack( + calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated, + callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc) + Some((warning, Nil)) + } else findIllegalAccess(callee.instructions, calleeDeclarationClass, callsiteClass) match { + case Right(Nil) => + None + + case Right(illegalAccessInsns) => + val warning = IllegalAccessInstruction( + calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated, + callsiteClass.internalName, illegalAccessInsns.head) + Some((warning, illegalAccessInsns)) + + case Left((illegalAccessIns, cause)) => + val warning = IllegalAccessCheckFailed( + calleeDeclarationClass.internalName, callee.name, callee.desc, callsite.isInlineAnnotated, + callsiteClass.internalName, illegalAccessIns, cause) + Some((warning, Nil)) } } @@ -624,13 +762,14 @@ class Inliner[BT <: BTypes](val btypes: BT) { } /** - * Returns the first instruction in the `instructions` list that would cause a - * [[java.lang.IllegalAccessError]] when inlined into the `destinationClass`. - * - * If validity of some instruction could not be checked because an error occurred, the instruction - * is returned together with a warning message that describes the problem. + * Returns + * - `Right(Nil)` if all instructions can be safely inlined + * - `Right(insns)` if inlining any of `insns` would cause a [[java.lang.IllegalAccessError]] + * when inlined into the `destinationClass` + * - `Left((insn, warning))` if validity of some instruction could not be checked because an + * error occurred */ - def findIllegalAccess(instructions: InsnList, calleeDeclarationClass: ClassBType, destinationClass: ClassBType): Option[(AbstractInsnNode, Option[OptimizerWarning])] = { + def findIllegalAccess(instructions: InsnList, calleeDeclarationClass: ClassBType, destinationClass: ClassBType): Either[(AbstractInsnNode, OptimizerWarning), List[AbstractInsnNode]] = { /** * Check if `instruction` can be transplanted to `destinationClass`. * @@ -759,17 +898,15 @@ class Inliner[BT <: BTypes](val btypes: BT) { } val it = instructions.iterator.asScala - @tailrec def find: Option[(AbstractInsnNode, Option[OptimizerWarning])] = { - if (!it.hasNext) None // all instructions are legal - else { - val i = it.next() - isLegal(i) match { - case Left(warning) => Some((i, Some(warning))) // checking isLegal for i failed - case Right(false) => Some((i, None)) // an illegal instruction was found - case _ => find - } + val illegalAccess = mutable.ListBuffer.empty[AbstractInsnNode] + while (it.hasNext) { + val i = it.next() + isLegal(i) match { + case Left(warning) => return Left((i, warning)) // checking isLegal for i failed + case Right(false) => illegalAccess += i // an illegal instruction was found + case _ => } } - find + Right(illegalAccess.toList) } } |