diff options
Diffstat (limited to 'src/compiler')
16 files changed, 356 insertions, 185 deletions
diff --git a/src/compiler/scala/tools/nsc/Reporting.scala b/src/compiler/scala/tools/nsc/Reporting.scala index 72a4b69536..4e7a527a5a 100644 --- a/src/compiler/scala/tools/nsc/Reporting.scala +++ b/src/compiler/scala/tools/nsc/Reporting.scala @@ -46,7 +46,7 @@ trait Reporting extends scala.reflect.internal.Reporting { self: ast.Positions w private val _deprecationWarnings = new ConditionalWarning("deprecation", settings.deprecation)() private val _uncheckedWarnings = new ConditionalWarning("unchecked", settings.unchecked)() private val _featureWarnings = new ConditionalWarning("feature", settings.feature)() - private val _inlinerWarnings = new ConditionalWarning("inliner", settings.YinlinerWarnings)(if (settings.isBCodeAskedFor) settings.YoptWarnings.name else settings.YinlinerWarnings.name) + private val _inlinerWarnings = new ConditionalWarning("inliner", settings.YinlinerWarnings)(if (settings.isBCodeActive) settings.YoptWarnings.name else settings.YinlinerWarnings.name) private val _allConditionalWarnings = List(_deprecationWarnings, _uncheckedWarnings, _featureWarnings, _inlinerWarnings) // TODO: remove in favor of the overload that takes a Symbol, give that argument a default (NoSymbol) diff --git a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala index b1b6c73f8d..cbe6239bb2 100644 --- a/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala +++ b/src/compiler/scala/tools/nsc/backend/icode/GenICode.scala @@ -883,7 +883,12 @@ abstract class GenICode extends SubComponent { case None => val saved = settings.uniqid settings.uniqid.value = true - try abort(s"symbol $sym does not exist in ${ctx.method}, which contains locals ${ctx.method.locals.mkString(",")}") + try { + val methodCode = unit.body.collect { case dd: DefDef + if dd.symbol == ctx.method.symbol => showCode(dd); + }.headOption.getOrElse("<unknown>") + abort(s"symbol $sym does not exist in ${ctx.method}, which contains locals ${ctx.method.locals.mkString(",")}. \nMethod code: $methodCode") + } finally settings.uniqid.value = saved } } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala index d8a17e975e..d690542f0e 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypes.scala @@ -11,11 +11,12 @@ import scala.collection.concurrent.TrieMap import scala.reflect.internal.util.Position import scala.tools.asm import asm.Opcodes -import scala.tools.asm.tree.{MethodInsnNode, InnerClassNode, ClassNode} +import scala.tools.asm.tree.{MethodNode, MethodInsnNode, InnerClassNode, ClassNode} import scala.tools.nsc.backend.jvm.BTypes.{InlineInfo, MethodInlineInfo} import scala.tools.nsc.backend.jvm.BackendReporting._ import scala.tools.nsc.backend.jvm.opt._ import scala.collection.convert.decorateAsScala._ +import scala.tools.nsc.settings.ScalaSettings /** * The BTypes component defines The BType class hierarchy. A BType stores all type information @@ -39,6 +40,8 @@ abstract class BTypes { */ val byteCodeRepository: ByteCodeRepository + val localOpt: LocalOpt[this.type] + val inliner: Inliner[this.type] val callGraph: CallGraph[this.type] @@ -48,14 +51,9 @@ abstract class BTypes { // Allows to define per-run caches here and in the CallGraph component, which don't have a global def recordPerRunCache[T <: collection.generic.Clearable](cache: T): T - // When building the call graph, we need to know if global inlining is allowed (the component doesn't have a global) - def inlineGlobalEnabled: Boolean - - // When the inliner is not enabled, there's no point in adding InlineInfos to all ClassBTypes - def inlinerEnabled: Boolean + // Allows access to the compiler settings for backend components that don't have a global in scope + def compilerSettings: ScalaSettings - // Settings that define what kind of optimizer warnings are emitted. - def warnSettings: WarnSettings /** * A map from internal names to ClassBTypes. Every ClassBType is added to this map on its @@ -83,6 +81,18 @@ abstract class BTypes { val javaDefinedClasses: collection.mutable.Set[InternalName] = recordPerRunCache(collection.mutable.Set.empty) /** + * Cache, contains methods whose unreachable instructions are eliminated. + * + * The ASM Analyzer class does not compute any frame information for unreachable instructions. + * Transformations that use an analyzer (including inlining) therefore require unreachable code + * to be eliminated. + * + * This cache allows running dead code elimination whenever an analyzer is used. If the method + * is already optimized, DCE can return early. + */ + val unreachableCodeEliminated: collection.mutable.Set[MethodNode] = recordPerRunCache(collection.mutable.Set.empty) + + /** * Obtain the BType for a type descriptor or internal name. For class descriptors, the ClassBType * is constructed by parsing the corresponding classfile. * @@ -229,7 +239,7 @@ abstract class BTypes { // The InlineInfo is built from the classfile (not from the symbol) for all classes that are NOT // being compiled. For those classes, the info is only needed if the inliner is enabled, othewise // we can save the memory. - if (!inlinerEnabled) BTypes.EmptyInlineInfo + if (!compilerSettings.YoptInlinerEnabled) BTypes.EmptyInlineInfo else fromClassfileAttribute getOrElse fromClassfileWithoutAttribute } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala index eeb6ed24a2..1b9fd5e298 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/BTypesFromSymbols.scala @@ -7,9 +7,10 @@ package scala.tools.nsc package backend.jvm import scala.tools.asm -import scala.tools.nsc.backend.jvm.opt.{CallGraph, Inliner, ByteCodeRepository} +import scala.tools.nsc.backend.jvm.opt.{LocalOpt, CallGraph, Inliner, ByteCodeRepository} import scala.tools.nsc.backend.jvm.BTypes.{InlineInfo, MethodInlineInfo, InternalName} import BackendReporting._ +import scala.tools.nsc.settings.ScalaSettings /** * This class mainly contains the method classBTypeFromSymbol, which extracts the necessary @@ -37,6 +38,8 @@ class BTypesFromSymbols[G <: Global](val global: G) extends BTypes { val byteCodeRepository = new ByteCodeRepository(global.classPath, javaDefinedClasses, recordPerRunCache(collection.concurrent.TrieMap.empty)) + val localOpt: LocalOpt[this.type] = new LocalOpt(this) + val inliner: Inliner[this.type] = new Inliner(this) val callGraph: CallGraph[this.type] = new CallGraph(this) @@ -49,19 +52,7 @@ class BTypesFromSymbols[G <: Global](val global: G) extends BTypes { def recordPerRunCache[T <: collection.generic.Clearable](cache: T): T = perRunCaches.recordCache(cache) - def inlineGlobalEnabled: Boolean = settings.YoptInlineGlobal - - def inlinerEnabled: Boolean = settings.YoptInlinerEnabled - - def warnSettings: WarnSettings = { - val c = settings.YoptWarningsChoices - // cannot extract settings.YoptWarnings into a local val due to some dependent typing issue. - WarnSettings( - !settings.YoptWarnings.isSetByUser || settings.YoptWarnings.contains(c.atInlineFailedSummary.name) || settings.YoptWarnings.contains(c.atInlineFailed.name), - settings.YoptWarnings.contains(c.noInlineMixed.name), - settings.YoptWarnings.contains(c.noInlineMissingBytecode.name), - settings.YoptWarnings.contains(c.noInlineMissingScalaInlineInfoAttr.name)) - } + def compilerSettings: ScalaSettings = settings // helpers that need access to global. // TODO @lry create a separate component, they don't belong to BTypesFromSymbols @@ -418,8 +409,8 @@ class BTypesFromSymbols[G <: Global](val global: G) extends BTypes { // phase travel required, see implementation of `compiles`. for nested classes, it checks if the // enclosingTopLevelClass is being compiled. after flatten, all classes are considered top-level, // so `compiles` would return `false`. - if (exitingPickler(currentRun.compiles(classSym))) buildFromSymbol // InlineInfo required for classes being compiled, we have to create the classfile attribute - else if (!inlinerEnabled) BTypes.EmptyInlineInfo // For other classes, we need the InlineInfo only inf the inliner is enabled. + if (exitingPickler(currentRun.compiles(classSym))) buildFromSymbol // InlineInfo required for classes being compiled, we have to create the classfile attribute + else if (!compilerSettings.YoptInlinerEnabled) BTypes.EmptyInlineInfo // For other classes, we need the InlineInfo only inf the inliner is enabled. else { // For classes not being compiled, the InlineInfo is read from the classfile attribute. This // fixes an issue with mixed-in methods: the mixin phase enters mixin methods only to class diff --git a/src/compiler/scala/tools/nsc/backend/jvm/BackendReporting.scala b/src/compiler/scala/tools/nsc/backend/jvm/BackendReporting.scala index a06fb4bab8..d641f708d2 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/BackendReporting.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/BackendReporting.scala @@ -4,6 +4,8 @@ package backend.jvm import scala.tools.asm.tree.{AbstractInsnNode, MethodNode} import scala.tools.nsc.backend.jvm.BTypes.InternalName import scala.reflect.internal.util.Position +import scala.tools.nsc.settings.ScalaSettings +import scala.util.control.ControlThrowable /** * Interface for emitting inline warnings. The interface is required because the implementation @@ -73,24 +75,22 @@ object BackendReporting { } } - case class Invalid[A](e: A) extends Exception + case class Invalid[A](e: A) extends ControlThrowable /** * See documentation of orThrow above. */ def tryEither[A, B](op: => Either[A, B]): Either[A, B] = try { op } catch { case Invalid(e) => Left(e.asInstanceOf[A]) } - final case class WarnSettings(atInlineFailed: Boolean, noInlineMixed: Boolean, noInlineMissingBytecode: Boolean, noInlineMissingScalaInlineInfoAttr: Boolean) - sealed trait OptimizerWarning { - def emitWarning(settings: WarnSettings): Boolean + def emitWarning(settings: ScalaSettings): Boolean } // Method filter in RightBiasedEither requires an implicit empty value. Taking the value here // in scope allows for-comprehensions that desugar into filter calls (for example when using a // tuple de-constructor). implicit object emptyOptimizerWarning extends OptimizerWarning { - def emitWarning(settings: WarnSettings): Boolean = false + def emitWarning(settings: ScalaSettings): Boolean = false } sealed trait MissingBytecodeWarning extends OptimizerWarning { @@ -112,17 +112,17 @@ object BackendReporting { missingClass.map(c => s" Reason:\n$c").getOrElse("") } - def emitWarning(settings: WarnSettings): Boolean = this match { + def emitWarning(settings: ScalaSettings): Boolean = this match { case ClassNotFound(_, javaDefined) => - if (javaDefined) settings.noInlineMixed - else settings.noInlineMissingBytecode + if (javaDefined) settings.YoptWarningNoInlineMixed + else settings.YoptWarningNoInlineMissingBytecode case m @ MethodNotFound(_, _, _, missing) => if (m.isArrayMethod) false - else settings.noInlineMissingBytecode || missing.exists(_.emitWarning(settings)) + else settings.YoptWarningNoInlineMissingBytecode || missing.exists(_.emitWarning(settings)) case FieldNotFound(_, _, _, missing) => - settings.noInlineMissingBytecode || missing.exists(_.emitWarning(settings)) + settings.YoptWarningNoInlineMissingBytecode || missing.exists(_.emitWarning(settings)) } } @@ -141,9 +141,9 @@ object BackendReporting { s"Failed to get the type of class symbol $classFullName due to SI-9111." } - def emitWarning(settings: WarnSettings): Boolean = this match { + def emitWarning(settings: ScalaSettings): Boolean = this match { case NoClassBTypeInfoMissingBytecode(cause) => cause.emitWarning(settings) - case NoClassBTypeInfoClassSymbolInfoFailedSI9111(_) => settings.noInlineMissingBytecode + case NoClassBTypeInfoClassSymbolInfoFailedSI9111(_) => settings.YoptWarningNoInlineMissingBytecode } } @@ -175,11 +175,11 @@ object BackendReporting { cause.toString } - def emitWarning(settings: WarnSettings): Boolean = this match { + def emitWarning(settings: ScalaSettings): Boolean = this match { case MethodInlineInfoIncomplete(_, _, _, cause) => cause.emitWarning(settings) case MethodInlineInfoMissing(_, _, _, Some(cause)) => cause.emitWarning(settings) - case MethodInlineInfoMissing(_, _, _, None) => settings.noInlineMissingBytecode + case MethodInlineInfoMissing(_, _, _, None) => settings.YoptWarningNoInlineMissingBytecode case MethodInlineInfoError(_, _, _, cause) => cause.emitWarning(settings) @@ -214,11 +214,21 @@ object BackendReporting { case SynchronizedMethod(_, _, _) => s"Method $calleeMethodSig cannot be inlined because it is synchronized." + + case StrictfpMismatch(_, _, _, callsiteClass, callsiteName, callsiteDesc) => + s"""The callsite method ${BackendReporting.methodSignature(callsiteClass, callsiteName, callsiteDesc)} + |does not have the same strictfp mode as the callee $calleeMethodSig. + """.stripMargin + + case ResultingMethodTooLarge(_, _, _, callsiteClass, callsiteName, callsiteDesc) => + s"""The size of the callsite method ${BackendReporting.methodSignature(callsiteClass, callsiteName, callsiteDesc)} + |would exceed the JVM method size limit after inlining $calleeMethodSig. + """.stripMargin } - def emitWarning(settings: WarnSettings): Boolean = this match { - case _: IllegalAccessInstruction | _: MethodWithHandlerCalledOnNonEmptyStack | _: SynchronizedMethod => - settings.atInlineFailed + def emitWarning(settings: ScalaSettings): Boolean = this match { + case _: IllegalAccessInstruction | _: MethodWithHandlerCalledOnNonEmptyStack | _: SynchronizedMethod | _: StrictfpMismatch | _: ResultingMethodTooLarge => + settings.YoptWarningEmitAtInlineFailed case IllegalAccessCheckFailed(_, _, _, _, _, cause) => cause.emitWarning(settings) @@ -231,6 +241,10 @@ object BackendReporting { case class MethodWithHandlerCalledOnNonEmptyStack(calleeDeclarationClass: InternalName, name: String, descriptor: String, callsiteClass: InternalName, callsiteName: String, callsiteDesc: String) extends CannotInlineWarning case class SynchronizedMethod(calleeDeclarationClass: InternalName, name: String, descriptor: String) extends CannotInlineWarning + case class StrictfpMismatch(calleeDeclarationClass: InternalName, name: String, descriptor: String, + callsiteClass: InternalName, callsiteName: String, callsiteDesc: String) extends CannotInlineWarning + case class ResultingMethodTooLarge(calleeDeclarationClass: InternalName, name: String, descriptor: String, + callsiteClass: InternalName, callsiteName: String, callsiteDesc: String) extends CannotInlineWarning /** * Used in the InlineInfo of a ClassBType, when some issue occurred obtaining the inline information. @@ -250,11 +264,11 @@ object BackendReporting { s"Cannot read ScalaInlineInfo version $version in classfile $internalName. Use a more recent compiler." } - def emitWarning(settings: WarnSettings): Boolean = this match { - case NoInlineInfoAttribute(_) => settings.noInlineMissingScalaInlineInfoAttr + def emitWarning(settings: ScalaSettings): Boolean = this match { + case NoInlineInfoAttribute(_) => settings.YoptWarningNoInlineMissingScalaInlineInfoAttr case ClassNotFoundWhenBuildingInlineInfoFromSymbol(cause) => cause.emitWarning(settings) - case ClassSymbolInfoFailureSI9111(_) => settings.noInlineMissingBytecode - case UnknownScalaInlineInfoVersion(_, _) => settings.noInlineMissingScalaInlineInfoAttr + case ClassSymbolInfoFailureSI9111(_) => settings.YoptWarningNoInlineMissingBytecode + case UnknownScalaInlineInfoVersion(_, _) => settings.YoptWarningNoInlineMissingScalaInlineInfoAttr } } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala index be1595dc29..c6ee36d7b2 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/GenBCode.scala @@ -14,7 +14,6 @@ import scala.reflect.internal.util.Statistics import scala.tools.asm import scala.tools.asm.tree.ClassNode -import scala.tools.nsc.backend.jvm.opt.LocalOpt /* * Prepare in-memory representations of classfiles using the ASM Tree API, and serialize them to disk. @@ -215,17 +214,12 @@ abstract class GenBCode extends BCodeSyncAndTry { * - converting the plain ClassNode to byte array and placing it on queue-3 */ class Worker2 { - lazy val localOpt = new LocalOpt(settings) - def runGlobalOptimizations(): Unit = { import scala.collection.convert.decorateAsScala._ q2.asScala foreach { case Item2(_, _, plain, _, _) => // skip mirror / bean: wd don't inline into tem, and they are not used in the plain class - if (plain != null) { - localOpt.minimalRemoveUnreachableCode(plain) - callGraph.addClass(plain) - } + if (plain != null) callGraph.addClass(plain) } bTypes.inliner.runInliner() } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala index 14e8cccc60..201ab15177 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala @@ -10,6 +10,7 @@ package opt import scala.annotation.{tailrec, switch} import scala.collection.mutable import scala.reflect.internal.util.Collections._ +import scala.tools.asm.commons.CodeSizeEvaluator import scala.tools.asm.tree.analysis._ import scala.tools.asm.{MethodWriter, ClassWriter, Label, Opcodes} import scala.tools.asm.tree._ @@ -21,6 +22,12 @@ import scala.tools.nsc.backend.jvm.BTypes._ object BytecodeUtils { + // http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.9.1 + final val maxJVMMethodSize = 65535 + + // 5% margin, more than enough for the instructions added by the inliner (store / load args, null check for instance methods) + final val maxMethodSizeAfterInline = maxJVMMethodSize - (maxJVMMethodSize / 20) + object Goto { def unapply(instruction: AbstractInsnNode): Option[JumpInsnNode] = { if (instruction.getOpcode == Opcodes.GOTO) Some(instruction.asInstanceOf[JumpInsnNode]) @@ -83,10 +90,14 @@ object BytecodeUtils { def isSynchronizedMethod(methodNode: MethodNode): Boolean = (methodNode.access & Opcodes.ACC_SYNCHRONIZED) != 0 + def isNativeMethod(methodNode: MethodNode): Boolean = (methodNode.access & Opcodes.ACC_NATIVE) != 0 + def isFinalClass(classNode: ClassNode): Boolean = (classNode.access & Opcodes.ACC_FINAL) != 0 def isFinalMethod(methodNode: MethodNode): Boolean = (methodNode.access & (Opcodes.ACC_FINAL | Opcodes.ACC_PRIVATE | Opcodes.ACC_STATIC)) != 0 + def isStrictfpMethod(methodNode: MethodNode): Boolean = (methodNode.access & Opcodes.ACC_STRICT) != 0 + def nextExecutableInstruction(instruction: AbstractInsnNode, alsoKeep: AbstractInsnNode => Boolean = Set()): Option[AbstractInsnNode] = { var result = instruction do { result = result.getNext } @@ -215,7 +226,7 @@ object BytecodeUtils { * to create a separate visitor for computing those values, duplicating the functionality from the * MethodWriter. */ - def computeMaxLocalsMaxStack(method: MethodNode) { + def computeMaxLocalsMaxStack(method: MethodNode): Unit = { val cw = new ClassWriter(ClassWriter.COMPUTE_MAXS) val excs = method.exceptions.asScala.toArray val mw = cw.visitMethod(method.access, method.name, method.desc, method.signature, excs).asInstanceOf[MethodWriter] @@ -224,6 +235,21 @@ object BytecodeUtils { method.maxStack = mw.getMaxStack } + def codeSizeOKForInlining(caller: MethodNode, callee: MethodNode): Boolean = { + // Looking at the implementation of CodeSizeEvaluator, all instructions except tableswitch and + // lookupswitch are <= 8 bytes. These should be rare enough for 8 to be an OK rough upper bound. + def roughUpperBound(methodNode: MethodNode): Int = methodNode.instructions.size * 8 + + def maxSize(methodNode: MethodNode): Int = { + val eval = new CodeSizeEvaluator(null) + methodNode.accept(eval) + eval.getMaxSize + } + + (roughUpperBound(caller) + roughUpperBound(callee) > maxMethodSizeAfterInline) && + (maxSize(caller) + maxSize(callee) > maxMethodSizeAfterInline) + } + def removeLineNumberNodes(classNode: ClassNode): Unit = { for (m <- classNode.methods.asScala) removeLineNumberNodes(m.instructions) } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala index 47d32c94cb..028f0f8fa6 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala @@ -43,14 +43,14 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // callee, we only check there for the methodInlineInfo, we should find it there. calleeDeclarationClassBType.info.orThrow.inlineInfo.methodInfos.get(methodSignature) match { case Some(methodInlineInfo) => - val canInlineFromSource = inlineGlobalEnabled || calleeSource == CompilationUnit + val canInlineFromSource = compilerSettings.YoptInlineGlobal || calleeSource == CompilationUnit val isAbstract = BytecodeUtils.isAbstractMethod(calleeMethodNode) // (1) A non-final method can be safe to inline if the receiver type is a final subclass. Example: // class A { @inline def f = 1 }; object B extends A; B.f // can be inlined // - // TODO: type analysis can render more calls statically resolved. Example˜∫ + // TODO: type analysis can render more calls statically resolved. Example: // new A.f // can be inlined, the receiver type is known to be exactly A. val isStaticallyResolved: Boolean = { methodInlineInfo.effectivelyFinal || @@ -68,8 +68,13 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // (2) Final trait methods can be rewritten from the interface to the static implementation // method to enable inlining. CallsiteInfo( - safeToInline = canInlineFromSource && isStaticallyResolved && !isAbstract, // (1) - safeToRewrite = canInlineFromSource && isRewritableTraitCall, // (2) + safeToInline = + canInlineFromSource && + isStaticallyResolved && // (1) + !isAbstract && + !BytecodeUtils.isConstructor(calleeMethodNode) && + !BytecodeUtils.isNativeMethod(calleeMethodNode), + safeToRewrite = canInlineFromSource && isRewritableTraitCall, // (2) annotatedInline = methodInlineInfo.annotatedInline, annotatedNoInline = methodInlineInfo.annotatedNoInline, warning = warning) @@ -92,6 +97,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // TODO: for now we run a basic analyzer to get the stack height at the call site. // once we run a more elaborate analyzer (types, nullness), we can get the stack height out of there. + localOpt.minimalRemoveUnreachableCode(methodNode, definingClass.internalName) val analyzer = new AsmAnalyzer(methodNode, definingClass.internalName) methodNode.instructions.iterator.asScala.collect({ 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 e14e57d3ab..ac5c9ce2e6 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala @@ -16,7 +16,7 @@ import scala.collection.convert.decorateAsJava._ import AsmUtils._ import BytecodeUtils._ import collection.mutable -import scala.tools.asm.tree.analysis.{SourceInterpreter, Analyzer} +import scala.tools.asm.tree.analysis.SourceInterpreter import BackendReporting._ import scala.tools.nsc.backend.jvm.BTypes.InternalName @@ -24,21 +24,39 @@ class Inliner[BT <: BTypes](val btypes: BT) { import btypes._ import callGraph._ + def eliminateUnreachableCodeAndUpdateCallGraph(methodNode: MethodNode, definingClass: InternalName): Unit = { + localOpt.minimalRemoveUnreachableCode(methodNode, definingClass) foreach { + case invocation: MethodInsnNode => callGraph.callsites.remove(invocation) + case _ => + } + } + def runInliner(): Unit = { rewriteFinalTraitMethodInvocations() for (request <- collectAndOrderInlineRequests) { val Right(callee) = request.callee // collectAndOrderInlineRequests returns callsites with a known callee - val r = inline(request.callsiteInstruction, request.callsiteStackHeight, request.callsiteMethod, request.callsiteClass, - callee.callee, callee.calleeDeclarationClass, - receiverKnownNotNull = false, keepLineNumbers = false) - - for (warning <- r) { - if ((callee.annotatedInline && btypes.warnSettings.atInlineFailed) || warning.emitWarning(warnSettings)) { - 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.callsitePosition, msg) + // Inlining a method can create unreachable code. Example: + // def f = throw e + // def g = f; println() // println is unreachable after inlining f + // If we have an inline request for a call to g, and f has been already inlined into g, we + // need to run DCE before inlining g. + eliminateUnreachableCodeAndUpdateCallGraph(callee.callee, callee.calleeDeclarationClass.internalName) + + // DCE above removes unreachable callsites from the call graph. If the inlining request denotes + // such an eliminated callsite, do nothing. + if (callGraph.callsites contains request.callsiteInstruction) { + val r = inline(request.callsiteInstruction, request.callsiteStackHeight, request.callsiteMethod, request.callsiteClass, + callee.callee, callee.calleeDeclarationClass, + receiverKnownNotNull = false, keepLineNumbers = false) + + for (warning <- r) { + if ((callee.annotatedInline && btypes.compilerSettings.YoptWarningEmitAtInlineFailed) || 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$warning" + backendReporting.inlinerWarning(request.callsitePosition, msg) + } } } } @@ -75,7 +93,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { val res = doInlineCallsite(callsite) if (!res) { - if (annotatedInline && btypes.warnSettings.atInlineFailed) { + if (annotatedInline && btypes.compilerSettings.YoptWarningEmitAtInlineFailed) { // if the callsite is annotated @inline, we report an inline warning even if the underlying // reason is, for example, mixed compilation (which has a separate -Yopt-warning flag). def initMsg = s"${BackendReporting.methodSignature(calleeDeclClass.internalName, callee)} is annotated @inline but cannot be inlined" @@ -86,7 +104,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { backendReporting.inlinerWarning(pos, s"$initMsg: the method is not final and may be overridden." + warnMsg) else backendReporting.inlinerWarning(pos, s"$initMsg." + warnMsg) - } else if (warning.isDefined && warning.get.emitWarning(warnSettings)) { + } else if (warning.isDefined && warning.get.emitWarning(compilerSettings)) { // when annotatedInline is false, and there is some warning, the callsite metadata is possibly incomplete. backendReporting.inlinerWarning(pos, s"there was a problem determining if method ${callee.name} can be inlined: \n"+ warning.get) } @@ -95,7 +113,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { res case Callsite(ins, _, _, Left(warning), _, _, pos) => - if (warning.emitWarning(warnSettings)) + if (warning.emitWarning(compilerSettings)) backendReporting.inlinerWarning(pos, s"failed to determine if ${ins.name} should be inlined:\n$warning") false }).toList @@ -106,7 +124,8 @@ class Inliner[BT <: BTypes](val btypes: BT) { */ def doInlineCallsite(callsite: Callsite): Boolean = callsite match { case Callsite(_, _, _, Right(Callee(callee, calleeDeclClass, safeToInline, _, annotatedInline, _, warning)), _, _, pos) => - annotatedInline && safeToInline + if (compilerSettings.YoptInlineHeuristics.value == "everything") safeToInline + else annotatedInline && safeToInline case _ => false } @@ -167,6 +186,8 @@ class Inliner[BT <: BTypes](val btypes: BT) { // VerifyError. We run a `SourceInterpreter` to find all producer instructions of the // receiver value and add a cast to the self type after each. if (!selfTypeOk) { + // there's no need to run eliminateUnreachableCode here. building the call graph does that + // already, no code can become unreachable in the meantime. val analyzer = new AsmAnalyzer(callsite.callsiteMethod, callsite.callsiteClass.internalName, new SourceInterpreter) val receiverValue = analyzer.frameAt(callsite.callsiteInstruction).peekDown(traitMethodArgumentTypes.length) for (i <- receiverValue.insns.asScala) { @@ -311,6 +332,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { val localVarShift = callsiteMethod.maxLocals clonedInstructions.iterator.asScala foreach { case varInstruction: VarInsnNode => varInstruction.`var` += localVarShift + case iinc: IincInsnNode => iinc.`var` += localVarShift case _ => () } @@ -433,6 +455,9 @@ class Inliner[BT <: BTypes](val btypes: BT) { // Remove the elided invocation from the call graph callGraph.callsites.remove(callsiteInstruction) + // Inlining a method body can render some code unreachable, see example above (in runInliner). + unreachableCodeEliminated -= callsiteMethod + callsiteMethod.maxLocals += returnType.getSize + callee.maxLocals callsiteMethod.maxStack = math.max(callsiteMethod.maxStack, callee.maxStack + callsiteStackHeight) @@ -472,10 +497,18 @@ class Inliner[BT <: BTypes](val btypes: BT) { callsiteStackHeight > expectedArgs } - if (isSynchronizedMethod(callee)) { + if (codeSizeOKForInlining(callsiteMethod, callee)) { + Some(ResultingMethodTooLarge( + calleeDeclarationClass.internalName, callee.name, callee.desc, + callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc)) + } else 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)) + } else if (isStrictfpMethod(callsiteMethod) != isStrictfpMethod(callee)) { + Some(StrictfpMismatch( + calleeDeclarationClass.internalName, callee.name, callee.desc, + callsiteClass.internalName, callsiteMethod.name, callsiteMethod.desc)) } else if (!callee.tryCatchBlocks.isEmpty && stackHasNonParameters) { Some(MethodWithHandlerCalledOnNonEmptyStack( calleeDeclarationClass.internalName, callee.name, callee.desc, diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala index f6cfc5598b..5f51a94673 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/LocalOpt.scala @@ -14,7 +14,6 @@ import scala.tools.asm.tree._ import scala.collection.convert.decorateAsScala._ import scala.tools.nsc.backend.jvm.BTypes.InternalName import scala.tools.nsc.backend.jvm.opt.BytecodeUtils._ -import scala.tools.nsc.settings.ScalaSettings /** * Optimizations within a single method. @@ -47,18 +46,9 @@ import scala.tools.nsc.settings.ScalaSettings * stale labels * - eliminate labels that are not referenced, merge sequences of label definitions. */ -class LocalOpt(settings: ScalaSettings) { - /** - * Remove unreachable code from all methods of `classNode`. See of its overload. - * - * @param classNode The class to optimize - * @return `true` if unreachable code was removed from any method - */ - def minimalRemoveUnreachableCode(classNode: ClassNode): Boolean = { - classNode.methods.asScala.foldLeft(false) { - case (changed, method) => minimalRemoveUnreachableCode(method, classNode.name) || changed - } - } +class LocalOpt[BT <: BTypes](val btypes: BT) { + import LocalOptImpls._ + import btypes._ /** * Remove unreachable code from a method. @@ -66,25 +56,30 @@ class LocalOpt(settings: ScalaSettings) { * This implementation only removes instructions that are unreachable for an ASM analyzer / * interpreter. This ensures that future analyses will not produce `null` frames. The inliner * and call graph builder depend on this property. + * + * @return A set containing the eliminated instructions */ - def minimalRemoveUnreachableCode(method: MethodNode, ownerClassName: InternalName): Boolean = { - if (method.instructions.size == 0) return false // fast path for abstract methods + def minimalRemoveUnreachableCode(method: MethodNode, ownerClassName: InternalName): Set[AbstractInsnNode] = { + if (method.instructions.size == 0) return Set.empty // fast path for abstract methods + if (unreachableCodeEliminated(method)) return Set.empty // we know there is no unreachable code // For correctness, after removing unreachable code, we have to eliminate empty exception // handlers, see scaladoc of def methodOptimizations. Removing an live handler may render more // code unreachable and therefore requires running another round. - def removalRound(): Boolean = { - val (codeRemoved, liveLabels) = removeUnreachableCodeImpl(method, ownerClassName) - if (codeRemoved) { + def removalRound(): Set[AbstractInsnNode] = { + val (removedInstructions, liveLabels) = removeUnreachableCodeImpl(method, ownerClassName) + val removedRecursively = if (removedInstructions.nonEmpty) { val liveHandlerRemoved = removeEmptyExceptionHandlers(method).exists(h => liveLabels(h.start)) if (liveHandlerRemoved) removalRound() - } - codeRemoved + else Set.empty + } else Set.empty + removedInstructions ++ removedRecursively } - val codeRemoved = removalRound() - if (codeRemoved) removeUnusedLocalVariableNodes(method)() - codeRemoved + val removedInstructions = removalRound() + if (removedInstructions.nonEmpty) removeUnusedLocalVariableNodes(method)() + unreachableCodeEliminated += method + removedInstructions } /** @@ -95,7 +90,7 @@ class LocalOpt(settings: ScalaSettings) { * @return `true` if unreachable code was eliminated in some method, `false` otherwise. */ def methodOptimizations(clazz: ClassNode): Boolean = { - !settings.YoptNone && clazz.methods.asScala.foldLeft(false) { + !compilerSettings.YoptNone && clazz.methods.asScala.foldLeft(false) { case (changed, method) => methodOptimizations(method, clazz.name) || changed } } @@ -144,15 +139,15 @@ class LocalOpt(settings: ScalaSettings) { def removalRound(): Boolean = { // unreachable-code, empty-handlers and simplify-jumps run until reaching a fixpoint (see doc on class LocalOpt) - val (codeRemoved, handlersRemoved, liveHandlerRemoved) = if (settings.YoptUnreachableCode) { - val (codeRemoved, liveLabels) = removeUnreachableCodeImpl(method, ownerClassName) + val (codeRemoved, handlersRemoved, liveHandlerRemoved) = if (compilerSettings.YoptUnreachableCode) { + val (removedInstructions, liveLabels) = removeUnreachableCodeImpl(method, ownerClassName) val removedHandlers = removeEmptyExceptionHandlers(method) - (codeRemoved, removedHandlers.nonEmpty, removedHandlers.exists(h => liveLabels(h.start))) + (removedInstructions.nonEmpty, removedHandlers.nonEmpty, removedHandlers.exists(h => liveLabels(h.start))) } else { (false, false, false) } - val jumpsChanged = if (settings.YoptSimplifyJumps) simplifyJumps(method) else false + val jumpsChanged = if (compilerSettings.YoptSimplifyJumps) simplifyJumps(method) else false // Eliminating live handlers and simplifying jump instructions may render more code // unreachable, so we need to run another round. @@ -165,13 +160,13 @@ class LocalOpt(settings: ScalaSettings) { // (*) Removing stale local variable descriptors is required for correctness of unreachable-code val localsRemoved = - if (settings.YoptCompactLocals) compactLocalVariables(method) // also removes unused - else if (settings.YoptUnreachableCode) removeUnusedLocalVariableNodes(method)() // (*) + if (compilerSettings.YoptCompactLocals) compactLocalVariables(method) // also removes unused + else if (compilerSettings.YoptUnreachableCode) removeUnusedLocalVariableNodes(method)() // (*) else false - val lineNumbersRemoved = if (settings.YoptEmptyLineNumbers) removeEmptyLineNumbers(method) else false + val lineNumbersRemoved = if (compilerSettings.YoptEmptyLineNumbers) removeEmptyLineNumbers(method) else false - val labelsRemoved = if (settings.YoptEmptyLabels) removeEmptyLabelNodes(method) else false + val labelsRemoved = if (compilerSettings.YoptEmptyLabels) removeEmptyLabelNodes(method) else false // assert that local variable annotations are empty (we don't emit them) - otherwise we'd have // to eliminate those covering an empty range, similar to removeUnusedLocalVariableNodes. @@ -179,15 +174,22 @@ class LocalOpt(settings: ScalaSettings) { assert(nullOrEmpty(method.visibleLocalVariableAnnotations), method.visibleLocalVariableAnnotations) assert(nullOrEmpty(method.invisibleLocalVariableAnnotations), method.invisibleLocalVariableAnnotations) + unreachableCodeEliminated += method + codeHandlersOrJumpsChanged || localsRemoved || lineNumbersRemoved || labelsRemoved } +} + +object LocalOptImpls { /** * Removes unreachable basic blocks. * * TODO: rewrite, don't use computeMaxLocalsMaxStack (runs a ClassWriter) / Analyzer. Too slow. + * + * @return A set containing eliminated instructions, and a set containing all live label nodes. */ - def removeUnreachableCodeImpl(method: MethodNode, ownerClassName: InternalName): (Boolean, Set[LabelNode]) = { + def removeUnreachableCodeImpl(method: MethodNode, ownerClassName: InternalName): (Set[AbstractInsnNode], Set[LabelNode]) = { // The data flow analysis requires the maxLocals / maxStack fields of the method to be computed. computeMaxLocalsMaxStack(method) val a = new Analyzer(new BasicInterpreter) @@ -197,6 +199,7 @@ class LocalOpt(settings: ScalaSettings) { val initialSize = method.instructions.size var i = 0 var liveLabels = Set.empty[LabelNode] + var removedInstructions = Set.empty[AbstractInsnNode] val itr = method.instructions.iterator() while (itr.hasNext) { itr.next() match { @@ -209,11 +212,12 @@ class LocalOpt(settings: ScalaSettings) { // Instruction iterators allow removing during iteration. // Removing is O(1): instructions are doubly linked list elements. itr.remove() + removedInstructions += ins } } i += 1 } - (method.instructions.size != initialSize, liveLabels) + (removedInstructions, liveLabels) } /** diff --git a/src/compiler/scala/tools/nsc/plugins/Plugin.scala b/src/compiler/scala/tools/nsc/plugins/Plugin.scala index 5a7a0df595..1a5529140c 100644 --- a/src/compiler/scala/tools/nsc/plugins/Plugin.scala +++ b/src/compiler/scala/tools/nsc/plugins/Plugin.scala @@ -60,13 +60,15 @@ abstract class Plugin { * @return true to continue, or false to opt out */ def init(options: List[String], error: String => Unit): Boolean = { - if (!options.isEmpty) error(s"Error: $name takes no options") + // call to deprecated method required here, we must continue to support + // code that subclasses that override `processOptions`. + processOptions(options, error) true } @deprecated("use Plugin#init instead", since="2.11") def processOptions(options: List[String], error: String => Unit): Unit = { - init(options, error) + if (!options.isEmpty) error(s"Error: $name takes no options") } /** A description of this plugin's options, suitable as a response diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala index d273995e6e..03fd0976e5 100644 --- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala +++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala @@ -256,6 +256,13 @@ trait ScalaSettings extends AbsScalaSettings def YoptInlineGlobal = Yopt.contains(YoptChoices.inlineGlobal) def YoptInlinerEnabled = YoptInlineProject || YoptInlineGlobal + val YoptInlineHeuristics = ChoiceSetting( + name = "-Yopt-inline-heuristics", + helpArg = "strategy", + descr = "Set the heuristics for inlining decisions.", + choices = List("at-inline-annotated", "everything"), + default = "at-inline-annotated") + object YoptWarningsChoices extends MultiChoiceEnumeration { val none = Choice("none" , "No optimizer warnings.") val atInlineFailedSummary = Choice("at-inline-failed-summary" , "One-line summary if there were @inline method calls that could not be inlined.") @@ -267,7 +274,7 @@ trait ScalaSettings extends AbsScalaSettings val YoptWarnings = MultiChoiceSetting( name = "-Yopt-warnings", - helpArg = "warnings", + helpArg = "warning", descr = "Enable optimizer warnings", domain = YoptWarningsChoices, default = Some(List(YoptWarningsChoices.atInlineFailed.name))) withPostSetHook (self => { @@ -275,6 +282,15 @@ trait ScalaSettings extends AbsScalaSettings else YinlinerWarnings.value = true }) + def YoptWarningEmitAtInlineFailed = + !YoptWarnings.isSetByUser || + YoptWarnings.contains(YoptWarningsChoices.atInlineFailedSummary) || + YoptWarnings.contains(YoptWarningsChoices.atInlineFailed) + + def YoptWarningNoInlineMixed = YoptWarnings.contains(YoptWarningsChoices.noInlineMixed) + def YoptWarningNoInlineMissingBytecode = YoptWarnings.contains(YoptWarningsChoices.noInlineMissingBytecode) + def YoptWarningNoInlineMissingScalaInlineInfoAttr = YoptWarnings.contains(YoptWarningsChoices.noInlineMissingScalaInlineInfoAttr) + private def removalIn212 = "This flag is scheduled for removal in 2.12. If you have a case where you need this flag then please report a bug." object YstatisticsPhases extends MultiChoiceEnumeration { val parser, typer, patmat, erasure, cleanup, jvm = Value } @@ -345,12 +361,7 @@ trait ScalaSettings extends AbsScalaSettings /** Test whether this is scaladoc we're looking at */ def isScaladoc = false - /** - * Helper utilities for use by checkConflictingSettings() - */ - def isBCodeActive = !isICodeAskedFor - def isBCodeAskedFor = (Ybackend.value != "GenASM") - def isICodeAskedFor = ((Ybackend.value == "GenASM") || optimiseSettings.exists(_.value) || writeICode.isSetByUser) + def isBCodeActive = Ybackend.value == "GenBCode" object MacroExpand { val None = "none" diff --git a/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala b/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala index 0b53dc37de..4ea569c8e6 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/Logic.scala @@ -9,8 +9,7 @@ package tools.nsc.transform.patmat import scala.language.postfixOps import scala.collection.mutable -import scala.reflect.internal.util.Statistics -import scala.reflect.internal.util.HashSet +import scala.reflect.internal.util.{NoPosition, Position, Statistics, HashSet} trait Logic extends Debugging { import PatternMatchingStats._ @@ -71,6 +70,8 @@ trait Logic extends Debugging { def unapply(v: Var): Some[Tree] } + def uncheckedWarning(pos: Position, msg: String): Unit + def reportWarning(message: String): Unit // resets hash consing -- only supposed to be called by TreeMakersToProps @@ -283,6 +284,23 @@ trait Logic extends Debugging { } } + // to govern how much time we spend analyzing matches for unreachability/exhaustivity + object AnalysisBudget { + val maxDPLLdepth = global.settings.YpatmatExhaustdepth.value + val maxFormulaSize = 100 * math.min(Int.MaxValue / 100, maxDPLLdepth) + + private def advice = + s"Please try with scalac -Ypatmat-exhaust-depth ${maxDPLLdepth * 2} or -Ypatmat-exhaust-depth off." + + def recursionDepthReached = + s"Exhaustivity analysis reached max recursion depth, not all missing cases are reported.\n($advice)" + + abstract class Exception(val advice: String) extends RuntimeException("CNF budget exceeded") + + object formulaSizeExceeded extends Exception(s"The analysis required more space than allowed.\n$advice") + + } + // TODO: remove since deprecated val budgetProp = scala.sys.Prop[String]("scalac.patmat.analysisBudget") if (budgetProp.isSet) { @@ -385,7 +403,7 @@ trait Logic extends Debugging { def findModelFor(solvable: Solvable): Model - def findAllModelsFor(solvable: Solvable): List[Solution] + def findAllModelsFor(solvable: Solvable, pos: Position = NoPosition): List[Solution] } } diff --git a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala index 34ebbc7463..cecb5c37be 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/MatchAnalysis.scala @@ -399,6 +399,7 @@ trait MatchAnalysis extends MatchApproximation { trait MatchAnalyzer extends MatchApproximator { def uncheckedWarning(pos: Position, msg: String) = currentRun.reporting.uncheckedWarning(pos, msg) + def warn(pos: Position, ex: AnalysisBudget.Exception, kind: String) = uncheckedWarning(pos, s"Cannot check match for $kind.\n${ex.advice}") def reportWarning(message: String) = global.reporter.warning(typer.context.tree.pos, message) // TODO: model dependencies between variables: if V1 corresponds to (x: List[_]) and V2 is (x.hd), V2 cannot be assigned when V1 = null or V1 = Nil @@ -429,44 +430,50 @@ trait MatchAnalysis extends MatchApproximation { val propsCasesOk = approximate(True) map caseWithoutBodyToProp val propsCasesFail = approximate(False) map (t => Not(caseWithoutBodyToProp(t))) - val (eqAxiomsFail, symbolicCasesFail) = removeVarEq(propsCasesFail, modelNull = true) - val (eqAxiomsOk, symbolicCasesOk) = removeVarEq(propsCasesOk, modelNull = true) - val eqAxioms = simplify(And(eqAxiomsOk, eqAxiomsFail)) // I'm pretty sure eqAxiomsOk == eqAxiomsFail, but not 100% sure. - - val prefix = mutable.ArrayBuffer[Prop]() - prefix += eqAxioms - - var prefixRest = symbolicCasesFail - var current = symbolicCasesOk - var reachable = true - var caseIndex = 0 - - debug.patmat("reachability, vars:\n" + ((propsCasesFail flatMap gatherVariables).distinct map (_.describe) mkString ("\n"))) - debug.patmat(s"equality axioms:\n$eqAxiomsOk") - - // invariant (prefixRest.length == current.length) && (prefix.reverse ++ prefixRest == symbolicCasesFail) - // termination: prefixRest.length decreases by 1 - while (prefixRest.nonEmpty && reachable) { - val prefHead = prefixRest.head - caseIndex += 1 - prefixRest = prefixRest.tail - if (prefixRest.isEmpty) reachable = true - else { - prefix += prefHead - current = current.tail + try { + val (eqAxiomsFail, symbolicCasesFail) = removeVarEq(propsCasesFail, modelNull = true) + val (eqAxiomsOk, symbolicCasesOk) = removeVarEq(propsCasesOk, modelNull = true) + val eqAxioms = simplify(And(eqAxiomsOk, eqAxiomsFail)) // I'm pretty sure eqAxiomsOk == eqAxiomsFail, but not 100% sure. + + val prefix = mutable.ArrayBuffer[Prop]() + prefix += eqAxioms + + var prefixRest = symbolicCasesFail + var current = symbolicCasesOk + var reachable = true + var caseIndex = 0 + + debug.patmat("reachability, vars:\n" + ((propsCasesFail flatMap gatherVariables).distinct map (_.describe) mkString ("\n"))) + debug.patmat(s"equality axioms:\n$eqAxiomsOk") + + // invariant (prefixRest.length == current.length) && (prefix.reverse ++ prefixRest == symbolicCasesFail) + // termination: prefixRest.length decreases by 1 + while (prefixRest.nonEmpty && reachable) { + val prefHead = prefixRest.head + caseIndex += 1 + prefixRest = prefixRest.tail + if (prefixRest.isEmpty) reachable = true + else { + prefix += prefHead + current = current.tail val and = And((current.head +: prefix): _*) val model = findModelFor(eqFreePropToSolvable(and)) - // debug.patmat("trying to reach:\n"+ cnfString(current.head) +"\nunder prefix:\n"+ cnfString(prefix)) - // if (NoModel ne model) debug.patmat("reached: "+ modelString(model)) + // debug.patmat("trying to reach:\n"+ cnfString(current.head) +"\nunder prefix:\n"+ cnfString(prefix)) + // if (NoModel ne model) debug.patmat("reached: "+ modelString(model)) - reachable = NoModel ne model + reachable = NoModel ne model + } } - } - if (Statistics.canEnable) Statistics.stopTimer(patmatAnaReach, start) + if (Statistics.canEnable) Statistics.stopTimer(patmatAnaReach, start) - if (reachable) None else Some(caseIndex) + if (reachable) None else Some(caseIndex) + } catch { + case ex: AnalysisBudget.Exception => + warn(prevBinder.pos, ex, "unreachability") + None // CNF budget exceeded + } } // exhaustivity @@ -507,32 +514,38 @@ trait MatchAnalysis extends MatchApproximation { // when does the match fail? val matchFails = Not(\/(symbolicCases)) - // debug output: + // debug output: debug.patmat("analysing:") showTreeMakers(cases) // debug.patmat("\nvars:\n"+ (vars map (_.describe) mkString ("\n"))) // debug.patmat("\nmatchFails as CNF:\n"+ cnfString(propToSolvable(matchFails))) - // find the models (under which the match fails) - val matchFailModels = findAllModelsFor(propToSolvable(matchFails)) + try { + // find the models (under which the match fails) + val matchFailModels = findAllModelsFor(propToSolvable(matchFails), prevBinder.pos) - val scrutVar = Var(prevBinderTree) - val counterExamples = { - matchFailModels.flatMap { - model => - val varAssignments = expandModel(model) - varAssignments.flatMap(modelToCounterExample(scrutVar) _) + val scrutVar = Var(prevBinderTree) + val counterExamples = { + matchFailModels.flatMap { + model => + val varAssignments = expandModel(model) + varAssignments.flatMap(modelToCounterExample(scrutVar) _) + } } - } - - // sorting before pruning is important here in order to - // keep neg/t7020.scala stable - // since e.g. List(_, _) would cover List(1, _) - val pruned = CounterExample.prune(counterExamples.sortBy(_.toString)).map(_.toString) - if (Statistics.canEnable) Statistics.stopTimer(patmatAnaExhaust, start) - pruned + // sorting before pruning is important here in order to + // keep neg/t7020.scala stable + // since e.g. List(_, _) would cover List(1, _) + val pruned = CounterExample.prune(counterExamples.sortBy(_.toString)).map(_.toString) + + if (Statistics.canEnable) Statistics.stopTimer(patmatAnaExhaust, start) + pruned + } catch { + case ex: AnalysisBudget.Exception => + warn(prevBinder.pos, ex, "exhaustivity") + Nil // CNF budget exceeded + } } } diff --git a/src/compiler/scala/tools/nsc/transform/patmat/Solving.scala b/src/compiler/scala/tools/nsc/transform/patmat/Solving.scala index 27217f0dc2..c43f1b6209 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/Solving.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/Solving.scala @@ -11,6 +11,7 @@ import scala.reflect.internal.util.Statistics import scala.language.postfixOps import scala.collection.mutable import scala.reflect.internal.util.Collections._ +import scala.reflect.internal.util.Position // a literal is a (possibly negated) variable class Lit(val v: Int) extends AnyVal { @@ -64,7 +65,12 @@ trait Solving extends Logic { def size = symbols.size } - case class Solvable(cnf: Cnf, symbolMapping: SymbolMapping) + final case class Solvable(cnf: Cnf, symbolMapping: SymbolMapping) { + def ++(other: Solvable) = { + require(this.symbolMapping eq other.symbolMapping) + Solvable(cnf ++ other.cnf, symbolMapping) + } + } trait CnfBuilder { private[this] val buff = ArrayBuffer[Clause]() @@ -95,7 +101,11 @@ trait Solving extends Logic { } } - def buildCnf: Array[Clause] = buff.toArray + def buildCnf: Array[Clause] = { + val cnf = buff.toArray + buff.clear() + cnf + } } @@ -244,19 +254,54 @@ trait Solving extends Logic { def eqFreePropToSolvable(p: Prop): Solvable = { + def doesFormulaExceedSize(p: Prop): Boolean = { + p match { + case And(ops) => + if (ops.size > AnalysisBudget.maxFormulaSize) { + true + } else { + ops.exists(doesFormulaExceedSize) + } + case Or(ops) => + if (ops.size > AnalysisBudget.maxFormulaSize) { + true + } else { + ops.exists(doesFormulaExceedSize) + } + case Not(a) => doesFormulaExceedSize(a) + case _ => false + } + } + + val simplified = simplify(p) + if (doesFormulaExceedSize(simplified)) { + throw AnalysisBudget.formulaSizeExceeded + } + // collect all variables since after simplification / CNF conversion // they could have been removed from the formula val symbolMapping = new SymbolMapping(gatherSymbols(p)) - - val simplified = simplify(p) val cnfExtractor = new AlreadyInCNF(symbolMapping) + val cnfTransformer = new TransformToCnf(symbolMapping) + + def cnfFor(prop: Prop): Solvable = { + prop match { + case cnfExtractor.ToCnf(solvable) => + // this is needed because t6942 would generate too many clauses with Tseitin + // already in CNF, just add clauses + solvable + case p => + cnfTransformer.apply(p) + } + } + simplified match { - case cnfExtractor.ToCnf(solvable) => - // this is needed because t6942 would generate too many clauses with Tseitin - // already in CNF, just add clauses - solvable - case p => - new TransformToCnf(symbolMapping).apply(p) + case And(props) => + // SI-6942: + // CNF(P1 /\ ... /\ PN) == CNF(P1) ++ CNF(...) ++ CNF(PN) + props.map(cnfFor).reduce(_ ++ _) + case p => + cnfFor(p) } } } @@ -288,7 +333,7 @@ trait Solving extends Logic { val NoTseitinModel: TseitinModel = null // returns all solutions, if any (TODO: better infinite recursion backstop -- detect fixpoint??) - def findAllModelsFor(solvable: Solvable): List[Solution] = { + def findAllModelsFor(solvable: Solvable, pos: Position): List[Solution] = { debug.patmat("find all models for\n"+ cnfString(solvable.cnf)) // we must take all vars from non simplified formula @@ -308,13 +353,12 @@ trait Solving extends Logic { final case class TseitinSolution(model: TseitinModel, unassigned: List[Int]) { def projectToSolution(symForVar: Map[Int, Sym]) = Solution(projectToModel(model, symForVar), unassigned map symForVar) } + def findAllModels(clauses: Array[Clause], models: List[TseitinSolution], - recursionDepthAllowed: Int = global.settings.YpatmatExhaustdepth.value): List[TseitinSolution]= + recursionDepthAllowed: Int = AnalysisBudget.maxDPLLdepth): List[TseitinSolution]= if (recursionDepthAllowed == 0) { - val maxDPLLdepth = global.settings.YpatmatExhaustdepth.value - reportWarning("(Exhaustivity analysis reached max recursion depth, not all missing cases are reported. " + - s"Please try with scalac -Ypatmat-exhaust-depth ${maxDPLLdepth * 2} or -Ypatmat-exhaust-depth off.)") + uncheckedWarning(pos, AnalysisBudget.recursionDepthReached) models } else { debug.patmat("find all models for\n" + cnfString(clauses)) diff --git a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala index db81eecdf5..e0d96df062 100644 --- a/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala +++ b/src/compiler/scala/tools/nsc/typechecker/SuperAccessors.scala @@ -322,7 +322,7 @@ abstract class SuperAccessors extends transform.Transform with transform.TypingT case Super(_, mix) => if (sym.isValue && !sym.isMethod || sym.hasAccessorFlag) { if (!settings.overrideVars) - reporter.error(tree.pos, "super may be not be used on " + sym.accessedOrSelf) + reporter.error(tree.pos, "super may not be used on " + sym.accessedOrSelf) } else if (isDisallowed(sym)) { reporter.error(tree.pos, "super not allowed here: use this." + name.decode + " instead") } |