diff options
Diffstat (limited to 'src')
19 files changed, 1428 insertions, 537 deletions
diff --git a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala index f866c0d038..76af40b330 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/GenASM.scala @@ -617,18 +617,16 @@ abstract class GenASM extends SubComponent with BytecodeWriters { self => val internalName = cachedJN.toString() val trackedSym = jsymbol(sym) reverseJavaName.get(internalName) match { - case Some(oldsym) if oldsym.exists && trackedSym.exists => - assert( - // In contrast, neither NothingClass nor NullClass show up bytecode-level. - (oldsym == trackedSym) || (oldsym == RuntimeNothingClass) || (oldsym == RuntimeNullClass) || (oldsym.isModuleClass && (oldsym.sourceModule == trackedSym.sourceModule)), - s"""|Different class symbols have the same bytecode-level internal name: - | name: $internalName - | oldsym: ${oldsym.fullNameString} - | tracked: ${trackedSym.fullNameString} - """.stripMargin - ) - case _ => + case None => reverseJavaName.put(internalName, trackedSym) + case Some(oldsym) => + // TODO: `duplicateOk` seems pretty ad-hoc (a more aggressive version caused SI-9356 because it called oldSym.exists, which failed in the unpickler; see also SI-5031) + def duplicateOk = oldsym == NoSymbol || trackedSym == NoSymbol || (syntheticCoreClasses contains oldsym) || (oldsym.isModuleClass && (oldsym.sourceModule == trackedSym.sourceModule)) + if (oldsym != trackedSym && !duplicateOk) + devWarning(s"""|Different class symbols have the same bytecode-level internal name: + | name: $internalName + | oldsym: ${oldsym.fullNameString} + | tracked: ${trackedSym.fullNameString}""".stripMargin) } } diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/AliasingFrame.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/AliasingFrame.scala new file mode 100644 index 0000000000..7bbe1e2a49 --- /dev/null +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/AliasingFrame.scala @@ -0,0 +1,251 @@ +package scala.tools.nsc +package backend.jvm +package analysis + +import scala.annotation.switch +import scala.collection.{mutable, immutable} +import scala.tools.asm.Opcodes +import scala.tools.asm.tree._ +import scala.tools.asm.tree.analysis.{Analyzer, Value, Frame, Interpreter} +import opt.BytecodeUtils._ + +object AliasingFrame { + private var _idCounter: Long = 0l + private def nextId = { _idCounter += 1; _idCounter } +} + +class AliasingFrame[V <: Value](nLocals: Int, nStack: Int) extends Frame[V](nLocals, nStack) { + import Opcodes._ + + // Auxiliary constructor required for implementing `AliasingAnalyzer.newFrame` + def this(src: Frame[_ <: V]) { + this(src.getLocals, src.getMaxStackSize) + init(src) + } + + /** + * For each slot (entry in the `values` array of the frame), an id that uniquely represents + * the object stored in it. If two values have the same id, they are aliases of the same + * object. + */ + private val aliasIds: Array[Long] = Array.fill(nLocals + nStack)(AliasingFrame.nextId) + + /** + * The object alias id of for a value index. + */ + def aliasId(entry: Int) = aliasIds(entry) + + /** + * Returns the indices of the values array which are aliases of the object `id`. + */ + def valuesWithAliasId(id: Long): Set[Int] = immutable.BitSet.empty ++ aliasIds.indices.iterator.filter(i => aliasId(i) == id) + + /** + * The set of aliased values for a given entry in the `values` array. + */ + def aliasesOf(entry: Int): Set[Int] = valuesWithAliasId(aliasIds(entry)) + + /** + * Define a new alias. For example, given + * var a = this // this, a have the same aliasId + * then an assignment + * b = a + * will set the same the aliasId for `b`. + */ + private def newAlias(assignee: Int, source: Int): Unit = { + aliasIds(assignee) = aliasIds(source) + } + + /** + * An assignment + * a = someUnknownValue() + * sets a fresh alias id for `a`. + * A stack value is also removed from its alias set when being consumed. + */ + private def removeAlias(assignee: Int): Unit = { + aliasIds(assignee) = AliasingFrame.nextId + } + + override def execute(insn: AbstractInsnNode, interpreter: Interpreter[V]): Unit = { + // Make the extendsion methods easier to use (otherwise we have to repeat `this`.stackTop) + def stackTop: Int = this.stackTop + def peekStack(n: Int): V = this.peekStack(n) + + // the val pattern `val (p, c) = f` still allocates a tuple (https://github.com/scala-opt/scala/issues/28) + val prodCons = InstructionStackEffect(insn, this) // needs to be called before super.execute, see its doc + val consumed = prodCons._1 + val produced = prodCons._2 + + super.execute(insn, interpreter) + + (insn.getOpcode: @switch) match { + case ALOAD => + newAlias(assignee = stackTop, source = insn.asInstanceOf[VarInsnNode].`var`) + + case DUP => + val top = stackTop + newAlias(assignee = top, source = top - 1) + + case DUP_X1 => + val top = stackTop + newAlias(assignee = top, source = top - 1) + newAlias(assignee = top - 1, source = top - 2) + newAlias(assignee = top - 2, source = top) + + case DUP_X2 => + // Check if the second element on the stack is size 2 + // https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-6.html#jvms-6.5.dup_x2 + val isSize2 = peekStack(1).getSize == 2 + val top = stackTop + newAlias(assignee = top, source = top - 1) + newAlias(assignee = top - 1, source = top - 2) + if (isSize2) { + // Size 2 values on the stack only take one slot in the `values` array + newAlias(assignee = top - 2, source = top) + } else { + newAlias(assignee = top - 2, source = top - 3) + newAlias(assignee = top - 3, source = top) + } + + case DUP2 => + val isSize2 = peekStack(0).getSize == 2 + val top = stackTop + if (isSize2) { + newAlias(assignee = top, source = top - 1) + } else { + newAlias(assignee = top - 1, source = top - 3) + newAlias(assignee = top, source = top - 2) + } + + case DUP2_X1 => + val isSize2 = peekStack(0).getSize == 2 + val top = stackTop + if (isSize2) { + newAlias(assignee = top, source = top - 1) + newAlias(assignee = top - 1, source = top - 2) + newAlias(assignee = top - 2, source = top) + } else { + newAlias(assignee = top, source = top - 2) + newAlias(assignee = top - 1, source = top - 3) + newAlias(assignee = top - 2, source = top - 4) + newAlias(assignee = top - 4, source = top) + newAlias(assignee = top - 5, source = top - 1) + } + + case DUP2_X2 => + val top = stackTop + // https://docs.oracle.com/javase/specs/jvms/se7/html/jvms-6.html#jvms-6.5.dup2_x2 + val v1isSize2 = peekStack(0).getSize == 2 + if (v1isSize2) { + newAlias(assignee = top, source = top - 1) + newAlias(assignee = top - 1, source = top - 2) + val v2isSize2 = peekStack(1).getSize == 2 + if (v2isSize2) { + // Form 4 + newAlias(assignee = top - 2, source = top) + } else { + // Form 2 + newAlias(assignee = top - 2, source = top - 3) + newAlias(assignee = top - 3, source = top) + } + } else { + newAlias(assignee = top, source = top - 2) + newAlias(assignee = top - 1, source = top - 3) + newAlias(assignee = top - 2, source = top - 4) + val v3isSize2 = peekStack(2).getSize == 2 + if (v3isSize2) { + // Form 3 + newAlias(assignee = top - 3, source = top) + newAlias(assignee = top - 4, source = top - 1) + } else { + // Form 1 + newAlias(assignee = top - 3, source = top - 5) + newAlias(assignee = top - 4, source = top) + newAlias(assignee = top - 5, source = top - 1) + } + } + + case SWAP => + val top = stackTop + val idTop = aliasIds(top) + aliasIds(top) = aliasIds(top - 1) + aliasIds(top - 1) = idTop + + case opcode => + if (opcode == ASTORE) { + // Not a separate case because we need to remove the consumed stack value from alias sets after. + val stackTopBefore = stackTop - produced + consumed + val local = insn.asInstanceOf[VarInsnNode].`var` + newAlias(assignee = local, source = stackTopBefore) + // if the value written is size 2, it overwrites the subsequent slot, which is then no + // longer an alias of anything. see the corresponding case in `Frame.execute`. + if (getLocal(local).getSize == 2) + removeAlias(local + 1) + + // if the value at the preceding index is size 2, it is no longer valid, so we remove its + // aliasing. see corresponding case in `Frame.execute` + if (local > 0) { + val precedingValue = getLocal(local - 1) + if (precedingValue != null && precedingValue.getSize == 2) + removeAlias(local - 1) + } + } + + // Remove consumed stack values from aliasing sets. + // Example: iadd + // - before: local1, local2, stack1, consumed1, consumed2 + // - after: local1, local2, stack1, produced1 // stackTop = 3 + val firstConsumed = stackTop - produced + 1 // firstConsumed = 3 + for (i <- 0 until consumed) + removeAlias(firstConsumed + i) // remove aliases for 3 and 4 + + // We don't need to set the aliases ids for the produced values: the aliasIds array already + // contains fresh ids for non-used stack values (ensured by removeAlias). + } + } + + /** + * Merge the AliasingFrame `other` into this AliasingFrame. + * + * Aliases that are common in both frames are kept. Example: + * + * var x, y = null + * if (...) { + * x = a + * y = a // (x, y, a) are aliases + * } else { + * x = a + * y = b // (x, a) and (y, b) + * } + * [...] // (x, a) + */ + override def merge(other: Frame[_ <: V], interpreter: Interpreter[V]): Boolean = { + val valuesChanged = super.merge(other, interpreter) + var aliasesChanged = false + val aliasingOther = other.asInstanceOf[AliasingFrame[_]] + for (i <- aliasIds.indices) { + val thisAliases = aliasesOf(i) + val thisNotOther = thisAliases diff (thisAliases intersect aliasingOther.aliasesOf(i)) + if (thisNotOther.nonEmpty) { + aliasesChanged = true + thisNotOther foreach removeAlias + } + } + valuesChanged || aliasesChanged + } + + override def init(src: Frame[_ <: V]): Frame[V] = { + super.init(src) + compat.Platform.arraycopy(src.asInstanceOf[AliasingFrame[_]].aliasIds, 0, aliasIds, 0, aliasIds.length) + this + } +} + +/** + * An analyzer that uses AliasingFrames instead of bare Frames. This can be used when an analysis + * needs to track aliases, but doesn't require a more specific Frame subclass. + */ +class AliasingAnalyzer[V <: Value](interpreter: Interpreter[V]) extends Analyzer[V](interpreter) { + override def newFrame(nLocals: Int, nStack: Int): AliasingFrame[V] = new AliasingFrame(nLocals, nStack) + override def newFrame(src: Frame[_ <: V]): AliasingFrame[V] = new AliasingFrame(src) +} diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/InstructionStackEffect.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/InstructionStackEffect.scala new file mode 100644 index 0000000000..98e93c125b --- /dev/null +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/InstructionStackEffect.scala @@ -0,0 +1,265 @@ +package scala.tools.nsc +package backend.jvm +package analysis + +import scala.annotation.switch +import scala.tools.asm.Opcodes._ +import scala.tools.asm.Type +import scala.tools.asm.tree.{MultiANewArrayInsnNode, InvokeDynamicInsnNode, MethodInsnNode, AbstractInsnNode} +import scala.tools.asm.tree.analysis.{Frame, Value} +import opt.BytecodeUtils._ +import collection.immutable + +object InstructionStackEffect { + private var cache: immutable.IntMap[(Int, Int)] = immutable.IntMap.empty + private def t(x: Int, y: Int): (Int, Int) = { + // x can go up to 255 (number of parameters of a method, dimensions in multianewarray) we cache + // x up to 10, which covers most cases and limits the cache. y doesn't go above 6 (see cases). + if (x > 10 || y > 6) (x, y) + else { + val key = (x << 8) + y // this would work for any x < 256 + if (cache contains key) { + cache(key) + } else { + val r = (x, y) + cache += key -> r + r + } + } + } + + /** + * Returns a pair with the number of stack values consumed and produced by `insn`. + * This method requires the `frame` to be in the state **before** executing / interpreting + * the `insn`. + */ + def apply[V <: Value](insn: AbstractInsnNode, frame: Frame[V]): (Int, Int) = { + def peekStack(n: Int): V = frame.peekStack(n) + + (insn.getOpcode: @switch) match { + // The order of opcodes is the same as in Frame.execute. + case NOP => t(0, 0) + + case ACONST_NULL | + ICONST_M1 | + ICONST_0 | + ICONST_1 | + ICONST_2 | + ICONST_3 | + ICONST_4 | + ICONST_5 | + LCONST_0 | + LCONST_1 | + FCONST_0 | + FCONST_1 | + FCONST_2 | + DCONST_0 | + DCONST_1 | + BIPUSH | + SIPUSH | + LDC | + ILOAD | + LLOAD | + FLOAD | + DLOAD | + ALOAD => t(0, 1) + + case IALOAD | + LALOAD | + FALOAD | + DALOAD | + AALOAD | + BALOAD | + CALOAD | + SALOAD => t(2, 1) + + case ISTORE | + LSTORE | + FSTORE | + DSTORE | + ASTORE => t(1, 0) + + case IASTORE | + LASTORE | + FASTORE | + DASTORE | + AASTORE | + BASTORE | + CASTORE | + SASTORE => t(3, 0) + + case POP => t(1, 0) + + case POP2 => + val isSize2 = peekStack(0).getSize == 2 + if (isSize2) t(1, 0) else t(2, 0) + + case DUP => t(0, 1) + + case DUP_X1 => t(2, 3) + + case DUP_X2 => + val isSize2 = peekStack(1).getSize == 2 + if (isSize2) t(2, 3) else t(3, 4) + + case DUP2 => + val isSize2 = peekStack(0).getSize == 2 + if (isSize2) t(0, 1) else t(0, 2) + + case DUP2_X1 => + val isSize2 = peekStack(0).getSize == 2 + if (isSize2) t(2, 3) else t(3, 4) + + case DUP2_X2 => + val v1isSize2 = peekStack(0).getSize == 2 + if (v1isSize2) { + val v2isSize2 = peekStack(1).getSize == 2 + if (v2isSize2) t(2, 3) else t(3, 4) + } else { + val v3isSize2 = peekStack(2).getSize == 2 + if (v3isSize2) t(3, 5) else t(4, 6) + } + + case SWAP => t(2, 2) + + case IADD | + LADD | + FADD | + DADD | + ISUB | + LSUB | + FSUB | + DSUB | + IMUL | + LMUL | + FMUL | + DMUL | + IDIV | + LDIV | + FDIV | + DDIV | + IREM | + LREM | + FREM | + DREM => t(2, 1) + + case INEG | + LNEG | + FNEG | + DNEG => t(1, 1) + + case ISHL | + LSHL | + ISHR | + LSHR | + IUSHR | + LUSHR | + IAND | + LAND | + IOR | + LOR | + IXOR | + LXOR => t(2, 1) + + case IINC => t(0, 0) + + case I2L | + I2F | + I2D | + L2I | + L2F | + L2D | + F2I | + F2L | + F2D | + D2I | + D2L | + D2F | + I2B | + I2C | + I2S => t(1, 1) + + case LCMP | + FCMPL | + FCMPG | + DCMPL | + DCMPG => t(2, 1) + + case IFEQ | + IFNE | + IFLT | + IFGE | + IFGT | + IFLE => t(1, 0) + + case IF_ICMPEQ | + IF_ICMPNE | + IF_ICMPLT | + IF_ICMPGE | + IF_ICMPGT | + IF_ICMPLE | + IF_ACMPEQ | + IF_ACMPNE => t(2, 0) + + case GOTO => t(0, 0) + + case JSR => t(0, 1) + + case RET => t(0, 0) + + case TABLESWITCH | + LOOKUPSWITCH => t(1, 0) + + case IRETURN | + LRETURN | + FRETURN | + DRETURN | + ARETURN => t(1, 0) // Frame.execute consumes one stack value + + case RETURN => t(0, 0) // Frame.execute does not change the stack + + case GETSTATIC => t(0, 1) + + case PUTSTATIC => t(1, 0) + + case GETFIELD => t(1, 1) + + case PUTFIELD => t(2, 0) + + case INVOKEVIRTUAL | + INVOKESPECIAL | + INVOKESTATIC | + INVOKEINTERFACE => + val desc = insn.asInstanceOf[MethodInsnNode].desc + val cons = Type.getArgumentTypes(desc).length + (if (insn.getOpcode == INVOKESTATIC) 0 else 1) + val prod = if (Type.getReturnType(desc) == Type.VOID_TYPE) 0 else 1 + t(cons, prod) + + case INVOKEDYNAMIC => + val desc = insn.asInstanceOf[InvokeDynamicInsnNode].desc + val cons = Type.getArgumentTypes(desc).length + val prod = if (Type.getReturnType(desc) == Type.VOID_TYPE) 0 else 1 + t(cons, prod) + + case NEW => t(0, 1) + + case NEWARRAY | + ANEWARRAY | + ARRAYLENGTH => t(1, 1) + + case ATHROW => t(1, 0) // Frame.execute consumes one stack value + + case CHECKCAST | + INSTANCEOF => t(1, 1) // Frame.execute does push(pop()) for both of them + + case MONITORENTER | + MONITOREXIT => t(1, 0) + + case MULTIANEWARRAY => t(insn.asInstanceOf[MultiANewArrayInsnNode].dims, 1) + + case IFNULL | + IFNONNULL => t(1, 0) + } + } + +} diff --git a/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala b/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala new file mode 100644 index 0000000000..31710dcbee --- /dev/null +++ b/src/compiler/scala/tools/nsc/backend/jvm/analysis/NullnessAnalyzer.scala @@ -0,0 +1,282 @@ +package scala.tools.nsc +package backend.jvm +package analysis + +import java.util + +import scala.annotation.switch +import scala.tools.asm.{Type, Opcodes} +import scala.tools.asm.tree.{MethodInsnNode, LdcInsnNode, AbstractInsnNode} +import scala.tools.asm.tree.analysis.{Frame, Analyzer, Interpreter, Value} +import scala.tools.nsc.backend.jvm.opt.BytecodeUtils +import BytecodeUtils._ + +/** + * Some notes on the ASM ananlyzer framework. + * + * Value + * - Abstract, needs to be implemented for each analysis. + * - Represents the desired information about local variables and stack values, for example: + * - Is this value known to be null / not null? + * - What are the instructions that could potentially have produced this value? + * + * Interpreter + * - Abstract, needs to be implemented for each analysis. Sometimes one can subclass an existing + * interpreter, e.g., SourceInterpreter or BasicInterpreter. + * - Multiple abstract methods that receive an instruction and the instruction's input values, and + * return a value representing the result of that instruction. + * - Note: due to control flow, the interpreter can be invoked multiple times for the same + * instruction, until reaching a fixed point. + * - Abstract `merge` function that computes the least upper bound of two values. Used by + * Frame.merge (see below). + * + * Frame + * - Can be used directly for many analyses, no subclass required. + * - Every frame has an array of values: one for each local variable and for each stack slot. + * - A `top` index stores the index of the current stack top + * - NOTE: for a size-2 local variable at index i, the local variable at i+1 is set to an empty + * value. However, for a size-2 value at index i on the stack, the value at i+1 holds the next + * stack value. + * - Defines the `execute(instruction)` method. + * - executing mutates the state of the frame according to the effect of the instruction + * - pop consumed values from the stack + * - pass them to the interpreter together with the instruction + * - if applicable, push the resulting value on the stack + * - Defines the `merge(otherFrame)` method + * - called by the analyzer when multiple control flow paths lead to an instruction + * - the frame at the branching instruction is merged into the current frame of the + * instruction (held by the analyzer) + * - mutates the values of the current frame, merges all values using interpreter.merge. + * + * Analyzer + * - Stores a frame for each instruction + * - `merge` function takes an instruction and a frame, merges the existing frame for that instr + * (from the frames array) with the new frame passed as argument. + * if the frame changed, puts the instruction on the work queue (fixpiont). + * - initial frame: initialized for first instr by calling interpreter.new[...]Value + * for each slot (locals and params), stored in frames[firstInstr] by calling `merge` + * - work queue of instructions (`queue` array, `top` index for next instruction to analyze) + * - analyze(method): simulate control flow. while work queue non-empty: + * - copy the state of `frames[instr]` into a local frame `current` + * - call `current.execute(instr, interpreter)`, mutating the `current` frame + * - if it's a branching instruction + * - for all potential destination instructions + * - merge the destination instruction frame with the `current` frame + * (this enqueues the destination instr if its frame changed) + * - invoke `newControlFlowEdge` (see below) + * - the analyzer also tracks active exception handlers at each instruction + * - the empty method `newControlFlowEdge` can be overridden to track control flow if required + * + * + * Some notes on nullness analysis. + * + * For an instance method, `this` is non-null at entry. So we have to return a NotNull value when + * the analyzer is initializing the first frame of a method (see above). This required a change of + * the analyzer: before it would simply call `interpreter.newValue`, where we don't have the + * required context. See https://github.com/scala/scala-asm/commit/8133d75032. + * + * After some operations we know that a certain value is not null (e.g. the receiver of an instance + * call). However, the receiver is an value on the stack and consumed while interpreting the + * instruction - so we can only gain some knowledge if we know that the receiver was an alias of + * some other local variable or stack slot. Therefore we use the AliasingFrame class. + * + * TODO: + * Finally, we'd also like to exploit the knowledge gained from `if (x == null)` tests: x is known + * to be null in one branch, not null in the other. This will make use of alias tracking as well. + * We still have to figure out how to do this exactly in the analyzer framework. + */ + +/** + * Type to represent nullness of values. + */ +sealed trait Nullness { + final def merge(other: Nullness) = if (this == other) this else Unknown +} +case object NotNull extends Nullness +case object Unknown extends Nullness +case object Null extends Nullness + +/** + * Represents the nullness state for a local variable or stack value. + * + * Note that nullness of primitive values is not tracked, it will be always [[Unknown]]. + */ +sealed trait NullnessValue extends Value { + /** + * The nullness of this value. + */ + def nullness: Nullness + + /** + * True if this value is a long or double. The Analyzer framework needs to know + * the size of each value when interpreting instructions, see `Frame.execute`. + */ + def isSize2: Boolean + /** + * The size of the slot described by this value. Cannot be 0 because no values are allocated + * for void-typed slots, see NullnessInterpreter.newValue. + **/ + def getSize: Int = if (isSize2) 2 else 1 + + def merge(other: NullnessValue) = NullnessValue(nullness merge other.nullness, isSize2) +} + +object NullValue extends NullnessValue { def nullness = Null; def isSize2 = false; override def toString = "Null" } +object UnknownValue1 extends NullnessValue { def nullness = Unknown; def isSize2 = false; override def toString = "Unknown1" } +object UnknownValue2 extends NullnessValue { def nullness = Unknown; def isSize2 = true; override def toString = "Unknown2" } +object NotNullValue extends NullnessValue { def nullness = NotNull; def isSize2 = false; override def toString = "NotNull" } + +object NullnessValue { + def apply(nullness: Nullness, isSize2: Boolean): NullnessValue = { + if (nullness == Null) NullValue + else if (nullness == NotNull) NotNullValue + else if (isSize2) UnknownValue2 + else UnknownValue1 + } + + def apply(nullness: Nullness, insn: AbstractInsnNode): NullnessValue = { + apply(nullness, isSize2 = BytecodeUtils.instructionResultSize(insn) == 2) + } +} + +final class NullnessInterpreter extends Interpreter[NullnessValue](Opcodes.ASM5) { + def newValue(tp: Type): NullnessValue = { + // ASM loves giving semantics to null. The behavior here is the same as in SourceInterpreter, + // which is provided by the framework. + // + // (1) For the void type, the ASM framework expects newValue to return `null`. + // Also, the Frame.returnValue field is `null` for methods with return type void. + // Example callsite passing VOID_TYPE: in Analyzer, `newValue(Type.getReturnType(m.desc))`. + // + // (2) `tp` may also be `null`. When creating the initial frame, the analyzer invokes + // `newValue(null)` for each local variable. We have to return a value of size 1. + if (tp == Type.VOID_TYPE) null // (1) + else NullnessValue(Unknown, isSize2 = tp != null /*(2)*/ && tp.getSize == 2 ) + } + + override def newParameterValue(isInstanceMethod: Boolean, local: Int, tp: Type): NullnessValue = { + // For instance methods, the `this` parameter is known to be not null. + if (isInstanceMethod && local == 0) NullnessValue(NotNull, isSize2 = false) + else super.newParameterValue(isInstanceMethod, local, tp) + } + + def newOperation(insn: AbstractInsnNode): NullnessValue = { + val nullness = (insn.getOpcode: @switch) match { + case Opcodes.ACONST_NULL => Null + + case Opcodes.LDC => insn.asInstanceOf[LdcInsnNode].cst match { + case _: String | _: Type => NotNull + case _ => Unknown + } + + case _ => Unknown + } + + // for Opcodes.NEW, we use Unknown. The value will become NotNull after the constructor call. + NullnessValue(nullness, insn) + } + + def copyOperation(insn: AbstractInsnNode, value: NullnessValue): NullnessValue = value + + def unaryOperation(insn: AbstractInsnNode, value: NullnessValue): NullnessValue = (insn.getOpcode: @switch) match { + case Opcodes.CHECKCAST => value + + case Opcodes.NEWARRAY | + Opcodes.ANEWARRAY => NullnessValue(NotNull, isSize2 = false) + + case _ => NullnessValue(Unknown, insn) + } + + def binaryOperation(insn: AbstractInsnNode, value1: NullnessValue, value2: NullnessValue): NullnessValue = { + NullnessValue(Unknown, insn) + } + + def ternaryOperation(insn: AbstractInsnNode, value1: NullnessValue, value2: NullnessValue, value3: NullnessValue): NullnessValue = { + NullnessValue(Unknown, isSize2 = false) + } + + def naryOperation(insn: AbstractInsnNode, values: util.List[_ <: NullnessValue]): NullnessValue = (insn.getOpcode: @switch) match { + case Opcodes.MULTIANEWARRAY => + NullnessValue(NotNull, isSize2 = false) + + case _ => + // TODO: use a list of methods that are known to return non-null values + NullnessValue(Unknown, insn) + } + + def returnOperation(insn: AbstractInsnNode, value: NullnessValue, expected: NullnessValue): Unit = () + + def merge(a: NullnessValue, b: NullnessValue): NullnessValue = a merge b +} + +class NullnessFrame(nLocals: Int, nStack: Int) extends AliasingFrame[NullnessValue](nLocals, nStack) { + // Auxiliary constructor required for implementing `NullnessAnalyzer.newFrame` + def this(src: Frame[_ <: NullnessValue]) { + this(src.getLocals, src.getMaxStackSize) + init(src) + } + + override def execute(insn: AbstractInsnNode, interpreter: Interpreter[NullnessValue]): Unit = { + import Opcodes._ + + // get the object id of the object that is known to be not-null after this operation + val nullCheckedAliasId: Long = (insn.getOpcode: @switch) match { + case IALOAD | + LALOAD | + FALOAD | + DALOAD | + AALOAD | + BALOAD | + CALOAD | + SALOAD => + aliasId(this.stackTop - 1) + + case IASTORE | + FASTORE | + AASTORE | + BASTORE | + CASTORE | + SASTORE | + LASTORE | + DASTORE => + aliasId(this.stackTop - 2) + + case GETFIELD => + aliasId(this.stackTop) + + case PUTFIELD => + aliasId(this.stackTop - 1) + + case INVOKEVIRTUAL | + INVOKESPECIAL | + INVOKEINTERFACE => + val desc = insn.asInstanceOf[MethodInsnNode].desc + val numArgs = Type.getArgumentTypes(desc).length + aliasId(this.stackTop - numArgs) + + case ARRAYLENGTH | + MONITORENTER | + MONITOREXIT => + aliasId(this.stackTop) + + case _ => + -1 + } + + super.execute(insn, interpreter) + + if (nullCheckedAliasId != -1) { + for (i <- valuesWithAliasId(nullCheckedAliasId)) + this.setValue(i, NotNullValue) + } + } +} + +/** + * This class is required to override the `newFrame` methods, which makes makes sure the analyzer + * uses NullnessFrames. + */ +class NullnessAnalyzer extends Analyzer[NullnessValue](new NullnessInterpreter) { + override def newFrame(nLocals: Int, nStack: Int): NullnessFrame = new NullnessFrame(nLocals, nStack) + override def newFrame(src: Frame[_ <: NullnessValue]): NullnessFrame = new NullnessFrame(src) +} 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 201ab15177..9bd016f964 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/BytecodeUtils.scala @@ -170,6 +170,8 @@ object BytecodeUtils { new InsnNode(op) } + def instructionResultSize(instruction: AbstractInsnNode) = InstructionResultSize(instruction) + def labelReferences(method: MethodNode): Map[LabelNode, Set[AnyRef]] = { val res = mutable.Map.empty[LabelNode, Set[AnyRef]] def add(l: LabelNode, ref: AnyRef) = if (res contains l) res(l) = res(l) + ref else res(l) = Set(ref) @@ -328,13 +330,38 @@ object BytecodeUtils { class AsmAnalyzer[V <: Value](methodNode: MethodNode, classInternalName: InternalName, interpreter: Interpreter[V] = new BasicInterpreter) { val analyzer = new Analyzer(interpreter) analyzer.analyze(classInternalName, methodNode) - def frameAt(instruction: AbstractInsnNode): Frame[V] = analyzer.getFrames()(methodNode.instructions.indexOf(instruction)) + def frameAt(instruction: AbstractInsnNode): Frame[V] = analyzer.frameAt(instruction, methodNode) + } + + implicit class AnalyzerExtensions[V <: Value](val analyzer: Analyzer[V]) extends AnyVal { + def frameAt(instruction: AbstractInsnNode, methodNode: MethodNode): Frame[V] = analyzer.getFrames()(methodNode.instructions.indexOf(instruction)) } - implicit class `frame extensions`[V <: Value](val frame: Frame[V]) extends AnyVal { - def peekDown(n: Int): V = { - val topIndex = frame.getStackSize - 1 - frame.getStack(topIndex - n) + implicit class FrameExtensions[V <: Value](val frame: Frame[V]) extends AnyVal { + /** + * The value `n` positions down the stack. + */ + def peekStack(n: Int): V = frame.getStack(frame.getStackSize - 1 - n) + + /** + * The index of the current stack top. + */ + def stackTop = frame.getLocals + frame.getStackSize - 1 + + /** + * Gets the value at slot i, where i may be a local or a stack index. + */ + def getValue(i: Int): V = { + if (i < frame.getLocals) frame.getLocal(i) + else frame.getStack(i - frame.getLocals) + } + + /** + * Sets the value at slot i, where i may be a local or a stack index. + */ + def setValue(i: Int, value: V): Unit = { + if (i < frame.getLocals) frame.setLocal(i, value) + else frame.setStack(i - frame.getLocals, value) } } } 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 028f0f8fa6..0932564b1f 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/CallGraph.scala @@ -8,12 +8,15 @@ package backend.jvm package opt import scala.reflect.internal.util.{NoPosition, Position} +import scala.tools.asm.tree.analysis.{Value, Analyzer, BasicInterpreter} +import scala.tools.asm.{Opcodes, Type} import scala.tools.asm.tree._ import scala.collection.convert.decorateAsScala._ -import scala.tools.nsc.backend.jvm.BTypes.{MethodInlineInfo, InternalName} +import scala.tools.nsc.backend.jvm.BTypes.InternalName import scala.tools.nsc.backend.jvm.BackendReporting._ -import scala.tools.nsc.backend.jvm.opt.BytecodeUtils.AsmAnalyzer +import scala.tools.nsc.backend.jvm.analysis.{NotNull, NullnessAnalyzer} import ByteCodeRepository.{Source, CompilationUnit} +import BytecodeUtils._ class CallGraph[BT <: BTypes](val btypes: BT) { import btypes._ @@ -93,12 +96,25 @@ class CallGraph[BT <: BTypes](val btypes: BT) { // TODO: run dataflow analyses to make the call graph more precise // - producers to get forwarded parameters (ForwardedParam) // - typeAnalysis for more precise argument types, more precise callee - // - nullAnalysis to skip emitting the receiver-null-check when inlining - // 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. + // For now we run a NullnessAnalyzer. It is used to determine if the receiver of an instance + // call is known to be not-null, in which case we don't have to emit a null check when inlining. + // It is also used to get the stack height at the call site. localOpt.minimalRemoveUnreachableCode(methodNode, definingClass.internalName) - val analyzer = new AsmAnalyzer(methodNode, definingClass.internalName) + + val analyzer: Analyzer[_ <: Value] = { + if (compilerSettings.YoptNullnessTracking) new NullnessAnalyzer + else new Analyzer(new BasicInterpreter) + } + analyzer.analyze(definingClass.internalName, methodNode) + + def receiverNotNullByAnalysis(call: MethodInsnNode, numArgs: Int) = analyzer match { + case nullnessAnalyzer: NullnessAnalyzer => + val frame = nullnessAnalyzer.frameAt(call, methodNode) + frame.getStack(frame.getStackSize - 1 - numArgs).nullness == NotNull + + case _ => false + } methodNode.instructions.iterator.asScala.collect({ case call: MethodInsnNode => @@ -126,13 +142,19 @@ class CallGraph[BT <: BTypes](val btypes: BT) { Nil } + val receiverNotNull = call.getOpcode == Opcodes.INVOKESTATIC || { + val numArgs = Type.getArgumentTypes(call.desc).length + receiverNotNullByAnalysis(call, numArgs) + } + Callsite( callsiteInstruction = call, callsiteMethod = methodNode, callsiteClass = definingClass, callee = callee, argInfos = argInfos, - callsiteStackHeight = analyzer.frameAt(call).getStackSize, + callsiteStackHeight = analyzer.frameAt(call, methodNode).getStackSize, + receiverKnownNotNull = receiverNotNull, callsitePosition = callsitePositions.getOrElse(call, NoPosition) ) }).toList @@ -154,7 +176,7 @@ class CallGraph[BT <: BTypes](val btypes: BT) { */ final case class Callsite(callsiteInstruction: MethodInsnNode, callsiteMethod: MethodNode, callsiteClass: ClassBType, callee: Either[OptimizerWarning, Callee], argInfos: List[ArgInfo], - callsiteStackHeight: Int, callsitePosition: Position) { + callsiteStackHeight: Int, receiverKnownNotNull: Boolean, callsitePosition: Position) { override def toString = "Invocation of" + s" ${callee.map(_.calleeDeclarationClass.internalName).getOrElse("?")}.${callsiteInstruction.name + callsiteInstruction.desc}" + 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 ac5c9ce2e6..814c78b69c 100644 --- a/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/Inliner.scala @@ -49,7 +49,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { 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) + request.receiverKnownNotNull, keepLineNumbers = false) for (warning <- r) { if ((callee.annotatedInline && btypes.compilerSettings.YoptWarningEmitAtInlineFailed) || warning.emitWarning(compilerSettings)) { @@ -89,7 +89,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { */ def selectCallsitesForInlining: List[Callsite] = { callsites.valuesIterator.filter({ - case callsite @ Callsite(_, _, _, Right(Callee(callee, calleeDeclClass, safeToInline, _, annotatedInline, _, warning)), _, _, pos) => + case callsite @ Callsite(_, _, _, Right(Callee(callee, calleeDeclClass, safeToInline, _, annotatedInline, _, warning)), _, _, _, pos) => val res = doInlineCallsite(callsite) if (!res) { @@ -112,7 +112,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { res - case Callsite(ins, _, _, Left(warning), _, _, pos) => + case Callsite(ins, _, _, Left(warning), _, _, _, pos) => if (warning.emitWarning(compilerSettings)) backendReporting.inlinerWarning(pos, s"failed to determine if ${ins.name} should be inlined:\n$warning") false @@ -123,7 +123,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { * The current inlining heuristics are simple: inline calls to methods annotated @inline. */ def doInlineCallsite(callsite: Callsite): Boolean = callsite match { - case Callsite(_, _, _, Right(Callee(callee, calleeDeclClass, safeToInline, _, annotatedInline, _, warning)), _, _, pos) => + case Callsite(_, _, _, Right(Callee(callee, calleeDeclClass, safeToInline, _, annotatedInline, _, warning)), _, _, _, pos) => if (compilerSettings.YoptInlineHeuristics.value == "everything") safeToInline else annotatedInline && safeToInline @@ -189,7 +189,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { // 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) + val receiverValue = analyzer.frameAt(callsite.callsiteInstruction).peekStack(traitMethodArgumentTypes.length) for (i <- receiverValue.insns.asScala) { val cast = new TypeInsnNode(CHECKCAST, selfParamType.internalName) callsite.callsiteMethod.instructions.insert(i, cast) @@ -215,6 +215,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { calleeInfoWarning = infoWarning)), argInfos = Nil, callsiteStackHeight = callsite.callsiteStackHeight, + receiverKnownNotNull = callsite.receiverKnownNotNull, callsitePosition = callsite.callsitePosition ) callGraph.callsites(newCallsiteInstruction) = staticCallsite @@ -400,7 +401,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { val inlinedReturn = instructionMap(originalReturn) val returnReplacement = new InsnList - def drop(slot: Int) = returnReplacement add getPop(frame.peekDown(slot).getSize) + def drop(slot: Int) = returnReplacement add getPop(frame.peekStack(slot).getSize) // for non-void methods, store the stack top into the return local variable if (hasReturnValue) { @@ -444,6 +445,7 @@ class Inliner[BT <: BTypes](val btypes: BT) { callee = originalCallsite.callee, argInfos = Nil, // TODO: re-compute argInfos for new destination (once we actually compute them) callsiteStackHeight = callsiteStackHeight + originalCallsite.callsiteStackHeight, + receiverKnownNotNull = originalCallsite.receiverKnownNotNull, callsitePosition = originalCallsite.callsitePosition ) diff --git a/src/compiler/scala/tools/nsc/backend/jvm/opt/InstructionResultSize.scala b/src/compiler/scala/tools/nsc/backend/jvm/opt/InstructionResultSize.scala new file mode 100644 index 0000000000..8d744f6d13 --- /dev/null +++ b/src/compiler/scala/tools/nsc/backend/jvm/opt/InstructionResultSize.scala @@ -0,0 +1,240 @@ +package scala.tools.nsc.backend.jvm.opt + +import scala.annotation.switch +import scala.tools.asm.{Handle, Type, Opcodes} +import scala.tools.asm.tree._ + +object InstructionResultSize { + import Opcodes._ + def apply(instruction: AbstractInsnNode): Int = (instruction.getOpcode: @switch) match { + // The order of opcodes is (almost) the same as in Opcodes.java + case ACONST_NULL => 1 + + case ICONST_M1 | + ICONST_0 | + ICONST_1 | + ICONST_2 | + ICONST_3 | + ICONST_4 | + ICONST_5 => 1 + + case LCONST_0 | + LCONST_1 => 2 + + case FCONST_0 | + FCONST_1 | + FCONST_2 => 1 + + case DCONST_0 | + DCONST_1 => 2 + + case BIPUSH | + SIPUSH => 1 + + case LDC => + instruction.asInstanceOf[LdcInsnNode].cst match { + case _: java.lang.Integer | + _: java.lang.Float | + _: String | + _: Type | + _: Handle => 1 + + case _: java.lang.Long | + _: java.lang.Double => 2 + } + + case ILOAD | + FLOAD | + ALOAD => 1 + + case LLOAD | + DLOAD => 2 + + case IALOAD | + FALOAD | + AALOAD | + BALOAD | + CALOAD | + SALOAD => 1 + + case LALOAD | + DALOAD => 2 + + case ISTORE | + LSTORE | + FSTORE | + DSTORE | + ASTORE => 0 + + case IASTORE | + LASTORE | + FASTORE | + DASTORE | + AASTORE | + BASTORE | + CASTORE | + SASTORE => 0 + + case POP | + POP2 => 0 + + case DUP | + DUP_X1 | + DUP_X2 | + DUP2 | + DUP2_X1 | + DUP2_X2 | + SWAP => throw new IllegalArgumentException("Can't compute the size of DUP/SWAP without knowing what's on stack top") + + case IADD | + FADD => 1 + + case LADD | + DADD => 2 + + case ISUB | + FSUB => 1 + + case LSUB | + DSUB => 2 + + case IMUL | + FMUL => 1 + + case LMUL | + DMUL => 2 + + case IDIV | + FDIV => 1 + + case LDIV | + DDIV => 2 + + case IREM | + FREM => 1 + + case LREM | + DREM => 2 + + case INEG | + FNEG => 1 + + case LNEG | + DNEG => 2 + + case ISHL | + ISHR => 1 + + case LSHL | + LSHR => 2 + + case IUSHR => 1 + + case LUSHR => 2 + + case IAND | + IOR | + IXOR => 1 + + case LAND | + LOR | + LXOR => 2 + + case IINC => 1 + + case I2F | + L2I | + L2F | + F2I | + D2I | + D2F | + I2B | + I2C | + I2S => 1 + + case I2L | + I2D | + L2D | + F2L | + F2D | + D2L => 2 + + case LCMP | + FCMPL | + FCMPG | + DCMPL | + DCMPG => 1 + + case IFEQ | + IFNE | + IFLT | + IFGE | + IFGT | + IFLE => 0 + + case IF_ICMPEQ | + IF_ICMPNE | + IF_ICMPLT | + IF_ICMPGE | + IF_ICMPGT | + IF_ICMPLE | + IF_ACMPEQ | + IF_ACMPNE => 0 + + case GOTO => 0 + + case JSR => throw new IllegalArgumentException("Subroutines are not supported.") + + case RET => 0 + + case TABLESWITCH | + LOOKUPSWITCH => 0 + + case IRETURN | + FRETURN | + ARETURN => 1 + + case LRETURN | + DRETURN => 2 + + case RETURN => 0 + + case GETSTATIC => Type.getType(instruction.asInstanceOf[FieldInsnNode].desc).getSize + + case PUTSTATIC => 0 + + case GETFIELD => Type.getType(instruction.asInstanceOf[FieldInsnNode].desc).getSize + + case PUTFIELD => 0 + + case INVOKEVIRTUAL | + INVOKESPECIAL | + INVOKESTATIC | + INVOKEINTERFACE => + val desc = instruction.asInstanceOf[MethodInsnNode].desc + Type.getReturnType(desc).getSize + + case INVOKEDYNAMIC => + val desc = instruction.asInstanceOf[InvokeDynamicInsnNode].desc + Type.getReturnType(desc).getSize + + case NEW => 1 + + case NEWARRAY | + ANEWARRAY | + ARRAYLENGTH => 1 + + case ATHROW => 0 + + case CHECKCAST | + INSTANCEOF => 1 + + case MONITORENTER | + MONITOREXIT => 0 + + case MULTIANEWARRAY => 1 + + case IFNULL | + IFNONNULL => 0 + } +} diff --git a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala index 35ee889c58..953e43eaca 100644 --- a/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala +++ b/src/compiler/scala/tools/nsc/settings/ScalaSettings.scala @@ -234,15 +234,16 @@ trait ScalaSettings extends AbsScalaSettings val emptyLineNumbers = Choice("empty-line-numbers", "Eliminate unnecessary line number information.") val emptyLabels = Choice("empty-labels", "Eliminate and collapse redundant labels in the bytecode.") val compactLocals = Choice("compact-locals", "Eliminate empty slots in the sequence of local variables.") - val inlineProject = Choice("inline-project", "Inline only methods defined in the files being compiled") - val inlineGlobal = Choice("inline-global", "Inline methods from any source, including classfiles on the compile classpath") + val nullnessTracking = Choice("nullness-tracking", "Track nullness / non-nullness of local variables and apply optimizations.") + val inlineProject = Choice("inline-project", "Inline only methods defined in the files being compiled.") + val inlineGlobal = Choice("inline-global", "Inline methods from any source, including classfiles on the compile classpath.") val lNone = Choice("l:none", "Don't enable any optimizations.") private val defaultChoices = List(unreachableCode) val lDefault = Choice("l:default", "Enable default optimizations: "+ defaultChoices.mkString(","), expandsTo = defaultChoices) - private val methodChoices = List(unreachableCode, simplifyJumps, emptyLineNumbers, emptyLabels, compactLocals) + private val methodChoices = List(unreachableCode, simplifyJumps, emptyLineNumbers, emptyLabels, compactLocals, nullnessTracking) val lMethod = Choice("l:method", "Enable intra-method optimizations: "+ methodChoices.mkString(","), expandsTo = methodChoices) private val projectChoices = List(lMethod, inlineProject) @@ -264,6 +265,7 @@ trait ScalaSettings extends AbsScalaSettings def YoptEmptyLineNumbers = Yopt.contains(YoptChoices.emptyLineNumbers) def YoptEmptyLabels = Yopt.contains(YoptChoices.emptyLabels) def YoptCompactLocals = Yopt.contains(YoptChoices.compactLocals) + def YoptNullnessTracking = Yopt.contains(YoptChoices.nullnessTracking) def YoptInlineProject = Yopt.contains(YoptChoices.inlineProject) def YoptInlineGlobal = Yopt.contains(YoptChoices.inlineGlobal) diff --git a/src/library/scala/collection/immutable/List.scala b/src/library/scala/collection/immutable/List.scala index 254f14f13c..82e38d3549 100644 --- a/src/library/scala/collection/immutable/List.scala +++ b/src/library/scala/collection/immutable/List.scala @@ -462,6 +462,7 @@ object List extends SeqFactory[List] { private class SerializationProxy[A](@transient private var orig: List[A]) extends Serializable { private def writeObject(out: ObjectOutputStream) { + out.defaultWriteObject() var xs: List[A] = orig while (!xs.isEmpty) { out.writeObject(xs.head) @@ -473,6 +474,7 @@ object List extends SeqFactory[List] { // Java serialization calls this before readResolve during de-serialization. // Read the whole list and store it in `orig`. private def readObject(in: ObjectInputStream) { + in.defaultReadObject() val builder = List.newBuilder[A] while (true) in.readObject match { case ListSerializeEnd => diff --git a/src/library/scala/collection/immutable/Queue.scala b/src/library/scala/collection/immutable/Queue.scala index 98266716cc..53af3ce158 100644 --- a/src/library/scala/collection/immutable/Queue.scala +++ b/src/library/scala/collection/immutable/Queue.scala @@ -56,11 +56,12 @@ class Queue[+A] protected(protected val in: List[A], protected val out: List[A]) * @throws java.util.NoSuchElementException if the queue is too short. */ override def apply(n: Int): A = { - val len = out.length - if (n < len) out.apply(n) + val olen = out.length + if (n < olen) out.apply(n) else { - val m = n - len - if (m < in.length) in.reverse.apply(m) + val m = n - olen + val ilen = in.length + if (m < ilen) in.apply(ilen - m - 1) else throw new NoSuchElementException("index out of range") } } diff --git a/src/library/scala/collection/mutable/ListBuffer.scala b/src/library/scala/collection/mutable/ListBuffer.scala index 8faaf97741..f9bab40a1e 100644 --- a/src/library/scala/collection/mutable/ListBuffer.scala +++ b/src/library/scala/collection/mutable/ListBuffer.scala @@ -15,7 +15,7 @@ import immutable.{List, Nil, ::} import java.io._ import scala.annotation.migration -/** A `Buffer` implementation back up by a list. It provides constant time +/** A `Buffer` implementation backed by a list. It provides constant time * prepend and append. Most other operations are linear. * * @author Matthias Zenger diff --git a/src/library/scala/math/BigDecimal.scala b/src/library/scala/math/BigDecimal.scala index d6e2963ad8..6bb35606a6 100644 --- a/src/library/scala/math/BigDecimal.scala +++ b/src/library/scala/math/BigDecimal.scala @@ -49,7 +49,7 @@ object BigDecimal { /** Constructs a `BigDecimal` using the decimal text representation of `Double` value `d`, rounding if necessary. */ def decimal(d: Double, mc: MathContext): BigDecimal = - new BigDecimal(new BigDec(java.lang.Double.toString(d), mc)) + new BigDecimal(new BigDec(java.lang.Double.toString(d), mc), mc) /** Constructs a `BigDecimal` using the decimal text representation of `Double` value `d`. */ def decimal(d: Double): BigDecimal = decimal(d, defaultMathContext) @@ -59,7 +59,7 @@ object BigDecimal { * `0.1 != 0.1f`. */ def decimal(f: Float, mc: MathContext): BigDecimal = - new BigDecimal(new BigDec(java.lang.Float.toString(f), mc)) + new BigDecimal(new BigDec(java.lang.Float.toString(f), mc), mc) /** Constructs a `BigDecimal` using the decimal text representation of `Float` value `f`. * Note that `BigDecimal.decimal(0.1f) != 0.1f` since equality agrees with the `Double` representation, and diff --git a/src/library/scala/math/Numeric.scala b/src/library/scala/math/Numeric.scala index eafbf96993..9245798c17 100644 --- a/src/library/scala/math/Numeric.scala +++ b/src/library/scala/math/Numeric.scala @@ -134,7 +134,7 @@ object Numeric { def div(x: Float, y: Float): Float = x / y } trait FloatAsIfIntegral extends FloatIsConflicted with Integral[Float] { - def quot(x: Float, y: Float): Float = (BigDecimal(x) / BigDecimal(y)).floatValue + def quot(x: Float, y: Float): Float = (BigDecimal(x) quot BigDecimal(y)).floatValue def rem(x: Float, y: Float): Float = (BigDecimal(x) remainder BigDecimal(y)).floatValue } implicit object FloatIsFractional extends FloatIsFractional with Ordering.FloatOrdering @@ -158,7 +158,7 @@ object Numeric { def div(x: Double, y: Double): Double = x / y } trait DoubleAsIfIntegral extends DoubleIsConflicted with Integral[Double] { - def quot(x: Double, y: Double): Double = (BigDecimal(x) / BigDecimal(y)).doubleValue + def quot(x: Double, y: Double): Double = (BigDecimal(x) quot BigDecimal(y)).doubleValue def rem(x: Double, y: Double): Double = (BigDecimal(x) remainder BigDecimal(y)).doubleValue } @@ -178,7 +178,7 @@ object Numeric { def div(x: BigDecimal, y: BigDecimal): BigDecimal = x / y } trait BigDecimalAsIfIntegral extends BigDecimalIsConflicted with Integral[BigDecimal] { - def quot(x: BigDecimal, y: BigDecimal): BigDecimal = x / y + def quot(x: BigDecimal, y: BigDecimal): BigDecimal = x quot y def rem(x: BigDecimal, y: BigDecimal): BigDecimal = x remainder y } diff --git a/src/library/scala/util/Sorting.scala b/src/library/scala/util/Sorting.scala index 2e021ad9d9..ee2bdbc4a7 100644 --- a/src/library/scala/util/Sorting.scala +++ b/src/library/scala/util/Sorting.scala @@ -1,6 +1,6 @@ /* __ *\ ** ________ ___ / / ___ Scala API ** -** / __/ __// _ | / / / _ | (c) 2006-2009, Ross Judson ** +** / __/ __// _ | / / / _ | (c) 2006-2015, LAMP/EPFL ** ** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** ** /____/\___/_/ |_/____/_/ | | ** ** |/ ** @@ -9,518 +9,276 @@ package scala package util -import scala.reflect.{ ClassTag, classTag } -import scala.math.{ Ordering, max, min } +import scala.reflect.ClassTag +import scala.math.Ordering -/** The Sorting object provides functions that can sort various kinds of - * objects. You can provide a comparison function, or you can request a sort - * of items that are viewable as [[scala.math.Ordered]]. Some sorts that - * operate directly on a subset of value types are also provided. These - * implementations are derived from those in the Sun JDK. +/** The `Sorting` object provides convenience wrappers for `java.util.Arrays.sort`. + * Methods that defer to `java.util.Arrays.sort` say that they do or under what + * conditions that they do. * - * Note that stability doesn't matter for value types, so use the `quickSort` - * variants for those. `stableSort` is intended to be used with - * objects when the prior ordering should be preserved, where possible. + * `Sorting` also implements a general-purpose quicksort and stable (merge) sort + * for those cases where `java.util.Arrays.sort` could only be used at the cost + * of a large memory penalty. If performance rather than memory usage is the + * primary concern, one may wish to find alternate strategies to use + * `java.util.Arrays.sort` directly e.g. by boxing primitives to use + * a custom ordering on them. + * + * `Sorting` provides methods where you can provide a comparison function, or + * can request a sort of items that are [[scala.math.Ordered]] or that + * otherwise have an implicit or explicit [[scala.math.Ordering]]. + * + * Note also that high-performance non-default sorts for numeric types + * are not provided. If this is required, it is advisable to investigate + * other libraries that cover this use case. * * @author Ross Judson - * @version 1.0 + * @author Adriaan Moors + * @author Rex Kerr + * @version 1.1 */ object Sorting { - /** Quickly sort an array of Doubles. */ - def quickSort(a: Array[Double]) { sort1(a, 0, a.length) } - - /** Quickly sort an array of items with an implicit Ordering. */ - def quickSort[K: Ordering](a: Array[K]) { sort1(a, 0, a.length) } - - /** Quickly sort an array of Ints. */ - def quickSort(a: Array[Int]) { sort1(a, 0, a.length) } - - /** Quickly sort an array of Floats. */ - def quickSort(a: Array[Float]) { sort1(a, 0, a.length) } - - /** Sort an array of K where K is Ordered, preserving the existing order - * where the values are equal. */ - def stableSort[K: ClassTag: Ordering](a: Array[K]) { - stableSort(a, 0, a.length-1, new Array[K](a.length), Ordering[K].lt _) - } + /** Sort an array of Doubles using `java.util.Arrays.sort`. */ + def quickSort(a: Array[Double]): Unit = java.util.Arrays.sort(a) - /** Sorts an array of `K` given an ordering function `f`. - * `f` should return `true` iff its first parameter is strictly less than its second parameter. - */ - def stableSort[K: ClassTag](a: Array[K], f: (K, K) => Boolean) { - stableSort(a, 0, a.length-1, new Array[K](a.length), f) - } + /** Sort an array of Ints using `java.util.Arrays.sort`. */ + def quickSort(a: Array[Int]): Unit = java.util.Arrays.sort(a) - /** Sorts an arbitrary sequence into an array, given a comparison function - * that should return `true` iff parameter one is strictly less than parameter two. - * - * @param a the sequence to be sorted. - * @param f the comparison function. - * @return the sorted sequence of items. - */ - def stableSort[K: ClassTag](a: Seq[K], f: (K, K) => Boolean): Array[K] = { - val ret = a.toArray - stableSort(ret, f) - ret - } + /** Sort an array of Floats using `java.util.Arrays.sort`. */ + def quickSort(a: Array[Float]): Unit = java.util.Arrays.sort(a) + + private final val qsortThreshold = 16 - /** Sorts an arbitrary sequence of items that are viewable as ordered. */ - def stableSort[K: ClassTag: Ordering](a: Seq[K]): Array[K] = - stableSort(a, Ordering[K].lt _) - - /** Stably sorts a sequence of items given an extraction function that will - * return an ordered key from an item. - * - * @param a the sequence to be sorted. - * @param f the comparison function. - * @return the sorted sequence of items. - */ - def stableSort[K: ClassTag, M: Ordering](a: Seq[K], f: K => M): Array[K] = - stableSort(a)(implicitly[ClassTag[K]], Ordering[M] on f) - - private def sort1[K: Ordering](x: Array[K], off: Int, len: Int) { - val ord = Ordering[K] - import ord._ - - def swap(a: Int, b: Int) { - val t = x(a) - x(a) = x(b) - x(b) = t - } - def vecswap(_a: Int, _b: Int, n: Int) { - var a = _a - var b = _b - var i = 0 - while (i < n) { - swap(a, b) - i += 1 - a += 1 - b += 1 - } - } - def med3(a: Int, b: Int, c: Int) = { - if (x(a) < x(b)) { - if (x(b) < x(c)) b else if (x(a) < x(c)) c else a - } else { - if (x(b) > x(c)) b else if (x(a) > x(c)) c else a - } - } - def sort2(off: Int, len: Int) { - // Insertion sort on smallest arrays - if (len < 7) { - var i = off - while (i < len + off) { - var j = i - while (j > off && x(j-1) > x(j)) { - swap(j, j-1) - j -= 1 + /** Sort array `a` with quicksort, using the Ordering on its elements. + * This algorithm sorts in place, so no additional memory is used aside from + * what might be required to box individual elements during comparison. + */ + def quickSort[K: Ordering](a: Array[K]): Unit = { + // Must have iN >= i0 or math will fail. Also, i0 >= 0. + def inner(a: Array[K], i0: Int, iN: Int, ord: Ordering[K]): Unit = { + if (iN - i0 < qsortThreshold) insertionSort(a, i0, iN, ord) + else { + var iK = (i0 + iN) >>> 1 // Unsigned div by 2 + // Find index of median of first, central, and last elements + var pL = + if (ord.compare(a(i0), a(iN - 1)) <= 0) + if (ord.compare(a(i0), a(iK)) < 0) + if (ord.compare(a(iN - 1), a(iK)) < 0) iN - 1 else iK + else i0 + else + if (ord.compare(a(i0), a(iK)) < 0) i0 + else + if (ord.compare(a(iN - 1), a(iK)) <= 0) iN - 1 + else iK + val pivot = a(pL) + // pL is the start of the pivot block; move it into the middle if needed + if (pL != iK) { a(pL) = a(iK); a(iK) = pivot; pL = iK } + // Elements equal to the pivot will be in range pL until pR + var pR = pL + 1 + // Items known to be less than pivot are below iA (range i0 until iA) + var iA = i0 + // Items known to be greater than pivot are at or above iB (range iB until iN) + var iB = iN + // Scan through everything in the buffer before the pivot(s) + while (pL - iA > 0) { + val current = a(iA) + ord.compare(current, pivot) match { + case 0 => + // Swap current out with pivot block + a(iA) = a(pL - 1) + a(pL - 1) = current + pL -= 1 + case x if x < 0 => + // Already in place. Just update indicies. + iA += 1 + case _ if iB > pR => + // Wrong side. There's room on the other side, so swap + a(iA) = a(iB - 1) + a(iB - 1) = current + iB -= 1 + case _ => + // Wrong side and there is no room. Swap by rotating pivot block. + a(iA) = a(pL - 1) + a(pL - 1) = a(pR - 1) + a(pR - 1) = current + pL -= 1 + pR -= 1 + iB -= 1 } - i += 1 } - } else { - // Choose a partition element, v - var m = off + (len >> 1) // Small arrays, middle element - if (len > 7) { - var l = off - var n = off + len - 1 - if (len > 40) { // Big arrays, pseudomedian of 9 - val s = len / 8 - l = med3(l, l+s, l+2*s) - m = med3(m-s, m, m+s) - n = med3(n-2*s, n-s, n) + // Get anything remaining in buffer after the pivot(s) + while (iB - pR > 0) { + val current = a(iB - 1) + ord.compare(current, pivot) match { + case 0 => + // Swap current out with pivot block + a(iB - 1) = a(pR) + a(pR) = current + pR += 1 + case x if x > 0 => + // Already in place. Just update indices. + iB -= 1 + case _ => + // Wrong side and we already know there is no room. Swap by rotating pivot block. + a(iB - 1) = a(pR) + a(pR) = a(pL) + a(pL) = current + iA += 1 + pL += 1 + pR += 1 } - m = med3(l, m, n) // Mid-size, med of 3 } - val v = x(m) - - // Establish Invariant: v* (<v)* (>v)* v* - var a = off - var b = a - var c = off + len - 1 - var d = c - var done = false - while (!done) { - while (b <= c && x(b) <= v) { - if (x(b) equiv v) { - swap(a, b) - a += 1 - } - b += 1 - } - while (c >= b && x(c) >= v) { - if (x(c) equiv v) { - swap(c, d) - d -= 1 - } - c -= 1 - } - if (b > c) { - done = true - } else { - swap(b, c) - c -= 1 - b += 1 - } + // Use tail recursion on large half (Sedgewick's method) so we don't blow up the stack if pivots are poorly chosen + if (iA - i0 < iN - iB) { + inner(a, i0, iA, ord) // True recursion + inner(a, iB, iN, ord) // Should be tail recursion + } + else { + inner(a, iB, iN, ord) // True recursion + inner(a, i0, iA, ord) // Should be tail recursion } - - // Swap partition elements back to middle - val n = off + len - var s = math.min(a-off, b-a) - vecswap(off, b-s, s) - s = math.min(d-c, n-d-1) - vecswap(b, n-s, s) - - // Recursively sort non-partition-elements - s = b - a - if (s > 1) - sort2(off, s) - s = d - c - if (s > 1) - sort2(n-s, s) } } - sort2(off, len) + inner(a, 0, a.length, implicitly[Ordering[K]]) } - - private def sort1(x: Array[Int], off: Int, len: Int) { - def swap(a: Int, b: Int) { - val t = x(a) - x(a) = x(b) - x(b) = t + + private final val mergeThreshold = 32 + + // Ordering[T] might be slow especially for boxed primitives, so use binary search variant of insertion sort + // Caller must pass iN >= i0 or math will fail. Also, i0 >= 0. + private def insertionSort[@specialized T](a: Array[T], i0: Int, iN: Int, ord: Ordering[T]): Unit = { + val n = iN - i0 + if (n < 2) return + if (ord.compare(a(i0), a(i0+1)) > 0) { + val temp = a(i0) + a(i0) = a(i0+1) + a(i0+1) = temp } - def vecswap(_a: Int, _b: Int, n: Int) { - var a = _a - var b = _b - var i = 0 - while (i < n) { - swap(a, b) - i += 1 - a += 1 - b += 1 - } - } - def med3(a: Int, b: Int, c: Int) = { - if (x(a) < x(b)) { - if (x(b) < x(c)) b else if (x(a) < x(c)) c else a - } else { - if (x(b) > x(c)) b else if (x(a) > x(c)) c else a - } - } - def sort2(off: Int, len: Int) { - // Insertion sort on smallest arrays - if (len < 7) { - var i = off - while (i < len + off) { - var j = i - while (j>off && x(j-1) > x(j)) { - swap(j, j-1) - j -= 1 - } - i += 1 + var m = 2 + while (m < n) { + // Speed up already-sorted case by checking last element first + val next = a(i0 + m) + if (ord.compare(next, a(i0+m-1)) < 0) { + var iA = i0 + var iB = i0 + m - 1 + while (iB - iA > 1) { + val ix = (iA + iB) >>> 1 // Use bit shift to get unsigned div by 2 + if (ord.compare(next, a(ix)) < 0) iB = ix + else iA = ix } - } else { - // Choose a partition element, v - var m = off + (len >> 1) // Small arrays, middle element - if (len > 7) { - var l = off - var n = off + len - 1 - if (len > 40) { // Big arrays, pseudomedian of 9 - val s = len / 8 - l = med3(l, l+s, l+2*s) - m = med3(m-s, m, m+s) - n = med3(n-2*s, n-s, n) - } - m = med3(l, m, n) // Mid-size, med of 3 - } - val v = x(m) - - // Establish Invariant: v* (<v)* (>v)* v* - var a = off - var b = a - var c = off + len - 1 - var d = c - var done = false - while (!done) { - while (b <= c && x(b) <= v) { - if (x(b) == v) { - swap(a, b) - a += 1 - } - b += 1 - } - while (c >= b && x(c) >= v) { - if (x(c) == v) { - swap(c, d) - d -= 1 - } - c -= 1 - } - if (b > c) { - done = true - } else { - swap(b, c) - c -= 1 - b += 1 - } + val ix = iA + (if (ord.compare(next, a(iA)) < 0) 0 else 1) + var i = i0 + m + while (i > ix) { + a(i) = a(i-1) + i -= 1 } - - // Swap partition elements back to middle - val n = off + len - var s = math.min(a-off, b-a) - vecswap(off, b-s, s) - s = math.min(d-c, n-d-1) - vecswap(b, n-s, s) - - // Recursively sort non-partition-elements - s = b - a - if (s > 1) - sort2(off, s) - s = d - c - if (s > 1) - sort2(n-s, s) + a(ix) = next } + m += 1 } - sort2(off, len) } - - private def sort1(x: Array[Double], off: Int, len: Int) { - def swap(a: Int, b: Int) { - val t = x(a) - x(a) = x(b) - x(b) = t + + // Caller is required to pass iN >= i0, else math will fail. Also, i0 >= 0. + private def mergeSort[@specialized T: ClassTag](a: Array[T], i0: Int, iN: Int, ord: Ordering[T], scratch: Array[T] = null): Unit = { + if (iN - i0 < mergeThreshold) insertionSort(a, i0, iN, ord) + else { + val iK = (i0 + iN) >>> 1 // Bit shift equivalent to unsigned math, no overflow + val sc = if (scratch eq null) new Array[T](iK - i0) else scratch + mergeSort(a, i0, iK, ord, sc) + mergeSort(a, iK, iN, ord, sc) + mergeSorted(a, i0, iK, iN, ord, sc) } - def vecswap(_a: Int, _b: Int, n: Int) { - var a = _a - var b = _b - var i = 0 - while (i < n) { - swap(a, b) + } + + // Must have 0 <= i0 < iK < iN + private def mergeSorted[@specialized T](a: Array[T], i0: Int, iK: Int, iN: Int, ord: Ordering[T], scratch: Array[T]): Unit = { + // Check to make sure we're not already in order + if (ord.compare(a(iK-1), a(iK)) > 0) { + var i = i0 + val jN = iK - i0 + var j = 0 + while (i < iK) { + scratch (j) = a(i) i += 1 - a += 1 - b += 1 - } - } - def med3(a: Int, b: Int, c: Int) = { - val ab = x(a) compare x(b) - val bc = x(b) compare x(c) - val ac = x(a) compare x(c) - if (ab < 0) { - if (bc < 0) b else if (ac < 0) c else a - } else { - if (bc > 0) b else if (ac > 0) c else a + j += 1 } - } - def sort2(off: Int, len: Int) { - // Insertion sort on smallest arrays - if (len < 7) { - var i = off - while (i < len + off) { - var j = i - while (j > off && (x(j-1) compare x(j)) > 0) { - swap(j, j-1) - j -= 1 - } - i += 1 - } - } else { - // Choose a partition element, v - var m = off + (len >> 1) // Small arrays, middle element - if (len > 7) { - var l = off - var n = off + len - 1 - if (len > 40) { // Big arrays, pseudomedian of 9 - val s = len / 8 - l = med3(l, l+s, l+2*s) - m = med3(m-s, m, m+s) - n = med3(n-2*s, n-s, n) - } - m = med3(l, m, n) // Mid-size, med of 3 - } - val v = x(m) - - // Establish Invariant: v* (<v)* (>v)* v* - var a = off - var b = a - var c = off + len - 1 - var d = c - var done = false - while (!done) { - var bv = x(b) compare v - while (b <= c && bv <= 0) { - if (bv == 0) { - swap(a, b) - a += 1 - } - b += 1 - if (b <= c) bv = x(b) compare v - } - var cv = x(c) compare v - while (c >= b && cv >= 0) { - if (cv == 0) { - swap(c, d) - d -= 1 - } - c -= 1 - if (c >= b) cv = x(c) compare v - } - if (b > c) { - done = true - } else { - swap(b, c) - c -= 1 - b += 1 - } - } - - // Swap partition elements back to middle - val n = off + len - var s = math.min(a-off, b-a) - vecswap(off, b-s, s) - s = math.min(d-c, n-d-1) - vecswap(b, n-s, s) - - // Recursively sort non-partition-elements - s = b - a - if (s > 1) - sort2(off, s) - s = d - c - if (s > 1) - sort2(n-s, s) + var k = i0 + j = 0 + while (i < iN && j < jN) { + if (ord.compare(a(i), scratch(j)) < 0) { a(k) = a(i); i += 1 } + else { a(k) = scratch(j); j += 1 } + k += 1 } + while (j < jN) { a(k) = scratch(j); j += 1; k += 1 } + // Don't need to finish a(i) because it's already in place, k = i } - sort2(off, len) } - - private def sort1(x: Array[Float], off: Int, len: Int) { - def swap(a: Int, b: Int) { - val t = x(a) - x(a) = x(b) - x(b) = t + + // Why would you even do this? + private def booleanSort(a: Array[Boolean]): Unit = { + var i = 0 + var n = 0 + while (i < a.length) { + if (!a(i)) n += 1 + i += 1 } - def vecswap(_a: Int, _b: Int, n: Int) { - var a = _a - var b = _b - var i = 0 - while (i < n) { - swap(a, b) - i += 1 - a += 1 - b += 1 - } + i = 0 + while (i < n) { + a(i) = false + i += 1 } - def med3(a: Int, b: Int, c: Int) = { - val ab = x(a) compare x(b) - val bc = x(b) compare x(c) - val ac = x(a) compare x(c) - if (ab < 0) { - if (bc < 0) b else if (ac < 0) c else a - } else { - if (bc > 0) b else if (ac > 0) c else a - } + while (i < a.length) { + a(i) = true + i += 1 } - def sort2(off: Int, len: Int) { - // Insertion sort on smallest arrays - if (len < 7) { - var i = off - while (i < len + off) { - var j = i - while (j > off && (x(j-1) compare x(j)) > 0) { - swap(j, j-1) - j -= 1 - } - i += 1 - } - } else { - // Choose a partition element, v - var m = off + (len >> 1) // Small arrays, middle element - if (len > 7) { - var l = off - var n = off + len - 1 - if (len > 40) { // Big arrays, pseudomedian of 9 - val s = len / 8 - l = med3(l, l+s, l+2*s) - m = med3(m-s, m, m+s) - n = med3(n-2*s, n-s, n) - } - m = med3(l, m, n) // Mid-size, med of 3 - } - val v = x(m) + } - // Establish Invariant: v* (<v)* (>v)* v* - var a = off - var b = a - var c = off + len - 1 - var d = c - var done = false - while (!done) { - var bv = x(b) compare v - while (b <= c && bv <= 0) { - if (bv == 0) { - swap(a, b) - a += 1 - } - b += 1 - if (b <= c) bv = x(b) compare v - } - var cv = x(c) compare v - while (c >= b && cv >= 0) { - if (cv == 0) { - swap(c, d) - d -= 1 - } - c -= 1 - if (c >= b) cv = x(c) compare v - } - if (b > c) { - done = true - } else { - swap(b, c) - c -= 1 - b += 1 - } - } + // TODO: add upper bound: T <: AnyRef, propagate to callers below (not binary compatible) + // Maybe also rename all these methods to `sort`. + @inline private def sort[T](a: Array[T], ord: Ordering[T]): Unit = a match { + case _: Array[AnyRef] => + // Note that runtime matches are covariant, so could actually be any Array[T] s.t. T is not primitive (even boxed value classes) + if (a.length > 1 && (ord eq null)) throw new NullPointerException("Ordering") + java.util.Arrays.sort(a, ord) + case a: Array[Int] => if (ord eq Ordering.Int) java.util.Arrays.sort(a) else mergeSort[Int](a, 0, a.length, ord) + case a: Array[Double] => mergeSort[Double](a, 0, a.length, ord) // Because not all NaNs are identical, stability is meaningful! + case a: Array[Long] => if (ord eq Ordering.Long) java.util.Arrays.sort(a) else mergeSort[Long](a, 0, a.length, ord) + case a: Array[Float] => mergeSort[Float](a, 0, a.length, ord) // Because not all NaNs are identical, stability is meaningful! + case a: Array[Char] => if (ord eq Ordering.Char) java.util.Arrays.sort(a) else mergeSort[Char](a, 0, a.length, ord) + case a: Array[Byte] => if (ord eq Ordering.Byte) java.util.Arrays.sort(a) else mergeSort[Byte](a, 0, a.length, ord) + case a: Array[Short] => if (ord eq Ordering.Short) java.util.Arrays.sort(a) else mergeSort[Short](a, 0, a.length, ord) + case a: Array[Boolean] => if (ord eq Ordering.Boolean) booleanSort(a) else mergeSort[Boolean](a, 0, a.length, ord) + // Array[Unit] is matched as an Array[AnyRef] due to covariance in runtime matching. Not worth catching it as a special case. + case null => throw new NullPointerException + } - // Swap partition elements back to middle - val n = off + len - var s = math.min(a-off, b-a) - vecswap(off, b-s, s) - s = math.min(d-c, n-d-1) - vecswap(b, n-s, s) + // TODO: remove unnecessary ClassTag (not binary compatible) + /** Sort array `a` using the Ordering on its elements, preserving the original ordering where possible. Uses `java.util.Arrays.sort` unless `K` is a primitive type. */ + def stableSort[K: ClassTag: Ordering](a: Array[K]): Unit = sort(a, Ordering[K]) - // Recursively sort non-partition-elements - s = b - a - if (s > 1) - sort2(off, s) - s = d - c - if (s > 1) - sort2(n-s, s) - } - } - sort2(off, len) + // TODO: Remove unnecessary ClassTag (not binary compatible) + // TODO: make this fast for primitive K (could be specialized if it didn't go through Ordering) + /** Sort array `a` using function `f` that computes the less-than relation for each element. Uses `java.util.Arrays.sort` unless `K` is a primitive type. */ + def stableSort[K: ClassTag](a: Array[K], f: (K, K) => Boolean): Unit = sort(a, Ordering fromLessThan f) + + /** A sorted Array, using the Ordering for the elements in the sequence `a`. Uses `java.util.Arrays.sort` unless `K` is a primitive type. */ + def stableSort[K: ClassTag: Ordering](a: Seq[K]): Array[K] = { + val ret = a.toArray + sort(ret, Ordering[K]) + ret } - private def stableSort[K : ClassTag](a: Array[K], lo: Int, hi: Int, scratch: Array[K], f: (K,K) => Boolean) { - if (lo < hi) { - val mid = (lo+hi) / 2 - stableSort(a, lo, mid, scratch, f) - stableSort(a, mid+1, hi, scratch, f) - var k, t_lo = lo - var t_hi = mid + 1 - while (k <= hi) { - if ((t_lo <= mid) && ((t_hi > hi) || (!f(a(t_hi), a(t_lo))))) { - scratch(k) = a(t_lo) - t_lo += 1 - } else { - scratch(k) = a(t_hi) - t_hi += 1 - } - k += 1 - } - k = lo - while (k <= hi) { - a(k) = scratch(k) - k += 1 - } - } + // TODO: make this fast for primitive K (could be specialized if it didn't go through Ordering) + /** A sorted Array, given a function `f` that computes the less-than relation for each item in the sequence `a`. Uses `java.util.Arrays.sort` unless `K` is a primitive type. */ + def stableSort[K: ClassTag](a: Seq[K], f: (K, K) => Boolean): Array[K] = { + val ret = a.toArray + sort(ret, Ordering fromLessThan f) + ret + } + + /** A sorted Array, given an extraction function `f` that returns an ordered key for each item in the sequence `a`. Uses `java.util.Arrays.sort` unless `K` is a primitive type. */ + def stableSort[K: ClassTag, M: Ordering](a: Seq[K], f: K => M): Array[K] = { + val ret = a.toArray + sort(ret, Ordering[M] on f) + ret } } diff --git a/src/library/scala/util/Try.scala b/src/library/scala/util/Try.scala index 0a6a7972c2..b0eae74043 100644 --- a/src/library/scala/util/Try.scala +++ b/src/library/scala/util/Try.scala @@ -48,7 +48,7 @@ import scala.language.implicitConversions * catching exceptions along the way. The `flatMap` and `map` combinators in the above example each essentially * pass off either their successfully completed value, wrapped in the `Success` type for it to be further operated * upon by the next combinator in the chain, or the exception wrapped in the `Failure` type usually to be simply - * passed on down the chain. Combinators such as `rescue` and `recover` are designed to provide some type of + * passed on down the chain. Combinators such as `recover` and `recoverWith` are designed to provide some type of * default behavior in the case of failure. * * ''Note'': only non-fatal exceptions are caught by the combinators on `Try` (see [[scala.util.control.NonFatal]]). diff --git a/src/reflect/scala/reflect/runtime/JavaMirrors.scala b/src/reflect/scala/reflect/runtime/JavaMirrors.scala index ce60ade9f5..8c32a92ecd 100644 --- a/src/reflect/scala/reflect/runtime/JavaMirrors.scala +++ b/src/reflect/scala/reflect/runtime/JavaMirrors.scala @@ -1184,6 +1184,7 @@ private[scala] trait JavaMirrors extends internal.SymbolTable with api.JavaUnive constr setInfo GenPolyType(tparams, MethodType(clazz.newSyntheticValueParams(paramtpes), clazz.tpe)) propagatePackageBoundary(jconstr.javaFlags, constr) copyAnnotations(constr, jconstr) + if (jconstr.javaFlags.isVarargs) constr modifyInfo arrayToRepeated markAllCompleted(constr) constr } diff --git a/src/repl/scala/tools/nsc/interpreter/IMain.scala b/src/repl/scala/tools/nsc/interpreter/IMain.scala index c281126d5f..e355d9f864 100644 --- a/src/repl/scala/tools/nsc/interpreter/IMain.scala +++ b/src/repl/scala/tools/nsc/interpreter/IMain.scala @@ -69,6 +69,8 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set // Used in a test case. def showDirectory() = replOutput.show(out) + lazy val isClassBased: Boolean = settings.Yreplclassbased.value + private[nsc] var printResults = true // whether to print result lines private[nsc] var totalSilence = false // whether to print anything private var _initializeComplete = false // compiler is initialized @@ -310,8 +312,14 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set } def originalPath(name: String): String = originalPath(TermName(name)) - def originalPath(name: Name): String = typerOp path name - def originalPath(sym: Symbol): String = typerOp path sym + def originalPath(name: Name): String = translateOriginalPath(typerOp path name) + def originalPath(sym: Symbol): String = translateOriginalPath(typerOp path sym) + /** For class based repl mode we use an .INSTANCE accessor. */ + val readInstanceName = if(isClassBased) ".INSTANCE" else "" + def translateOriginalPath(p: String): String = { + val readName = java.util.regex.Matcher.quoteReplacement(sessionNames.read) + p.replaceFirst(readName, readName + readInstanceName) + } def flatPath(sym: Symbol): String = flatOp shift sym.javaClassName def translatePath(path: String) = { @@ -758,11 +766,13 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set // object and we can do that much less wrapping. def packageDecl = "package " + packageName + def pathToInstance(name: String) = packageName + "." + name + readInstanceName def pathTo(name: String) = packageName + "." + name def packaged(code: String) = packageDecl + "\n\n" + code - def readPath = pathTo(readName) - def evalPath = pathTo(evalName) + def readPathInstance = pathToInstance(readName) + def readPath = pathTo(readName) + def evalPath = pathTo(evalName) def call(name: String, args: Any*): AnyRef = { val m = evalMethod(name) @@ -802,7 +812,8 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set /** The innermost object inside the wrapper, found by * following accessPath into the outer one. */ - def resolvePathToSymbol(accessPath: String): Symbol = { + def resolvePathToSymbol(fullAccessPath: String): Symbol = { + val accessPath = fullAccessPath.stripPrefix(readPath) val readRoot = readRootPath(readPath) // the outermost wrapper (accessPath split '.').foldLeft(readRoot: Symbol) { case (sym, "") => sym @@ -849,7 +860,6 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set def defines = defHandlers flatMap (_.definedSymbols) def imports = importedSymbols def value = Some(handlers.last) filter (h => h.definesValue) map (h => definedSymbols(h.definesTerm.get)) getOrElse NoSymbol - val lineRep = new ReadEvalPrint() private var _originalLine: String = null @@ -858,6 +868,11 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set /** handlers for each tree in this request */ val handlers: List[MemberHandler] = trees map (memberHandlers chooseHandler _) + val definesClass = handlers.exists { + case _: ClassHandler => true + case _ => false + } + def defHandlers = handlers collect { case x: MemberDefHandler => x } /** list of names used by this expression */ @@ -875,13 +890,13 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set * append to objectName to access anything bound by request. */ lazy val ComputedImports(importsPreamble, importsTrailer, accessPath) = - exitingTyper(importsCode(referencedNames.toSet, ObjectSourceCode)) + exitingTyper(importsCode(referencedNames.toSet, ObjectSourceCode, definesClass)) /** the line of code to compute */ def toCompute = line /** The path of the value that contains the user code. */ - def fullAccessPath = s"${lineRep.readPath}$accessPath" + def fullAccessPath = s"${lineRep.readPathInstance}$accessPath" /** The path of the given member of the wrapping instance. */ def fullPath(vname: String) = s"$fullAccessPath.`$vname`" @@ -911,7 +926,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set def postwrap: String } - private class ObjectBasedWrapper extends Wrapper { + class ObjectBasedWrapper extends Wrapper { def preambleHeader = "object %s {" def postamble = importsTrailer + "\n}" @@ -919,13 +934,16 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set def postwrap = "}\n" } - private class ClassBasedWrapper extends Wrapper { - def preambleHeader = "class %s extends Serializable {" + class ClassBasedWrapper extends Wrapper { + def preambleHeader = "class %s extends Serializable { " /** Adds an object that instantiates the outer wrapping class. */ - def postamble = s"""$importsTrailer + def postamble = s""" + |$importsTrailer + |} + |object ${lineRep.readName} { + | val INSTANCE = new ${lineRep.readName}(); |} - |object ${lineRep.readName} extends ${lineRep.readName} |""".stripMargin import nme.{ INTERPRETER_IMPORT_WRAPPER => iw } @@ -935,7 +953,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set } private lazy val ObjectSourceCode: Wrapper = - if (settings.Yreplclassbased) new ClassBasedWrapper else new ObjectBasedWrapper + if (isClassBased) new ClassBasedWrapper else new ObjectBasedWrapper private object ResultObjectSourceCode extends IMain.CodeAssembler[MemberHandler] { /** We only want to generate this code when the result @@ -994,7 +1012,7 @@ class IMain(@BeanProperty val factory: ScriptEngineFactory, initialSettings: Set } } - lazy val resultSymbol = lineRep.resolvePathToSymbol(accessPath) + lazy val resultSymbol = lineRep.resolvePathToSymbol(fullAccessPath) def applyToResultMember[T](name: Name, f: Symbol => T) = exitingTyper(f(resultSymbol.info.nonPrivateDecl(name))) /* typeOf lookup with encoding */ diff --git a/src/repl/scala/tools/nsc/interpreter/Imports.scala b/src/repl/scala/tools/nsc/interpreter/Imports.scala index 5244858a62..3ec77e46f1 100644 --- a/src/repl/scala/tools/nsc/interpreter/Imports.scala +++ b/src/repl/scala/tools/nsc/interpreter/Imports.scala @@ -92,7 +92,7 @@ trait Imports { * last one imported is actually usable. */ case class ComputedImports(prepend: String, append: String, access: String) - protected def importsCode(wanted: Set[Name], wrapper: Request#Wrapper): ComputedImports = { + protected def importsCode(wanted: Set[Name], wrapper: Request#Wrapper, definesClass: Boolean): ComputedImports = { /** Narrow down the list of requests from which imports * should be taken. Removes requests which cannot contribute * useful imports for the specified set of wanted names. @@ -107,6 +107,8 @@ trait Imports { // Single symbol imports might be implicits! See bug #1752. Rather than // try to finesse this, we will mimic all imports for now. def keepHandler(handler: MemberHandler) = handler match { + /* While defining classes in class based mode - implicits are not needed. */ + case h: ImportHandler if isClassBased && definesClass => h.importedNames.exists(x => wanted.contains(x)) case _: ImportHandler => true case x => x.definesImplicit || (x.definedNames exists wanted) } @@ -146,7 +148,10 @@ trait Imports { // loop through previous requests, adding imports for each one wrapBeforeAndAfter { + // Reusing a single temporary value when import from a line with multiple definitions. + val tempValLines = mutable.Set[Int]() for (ReqAndHandler(req, handler) <- reqsToUse) { + val objName = req.lineRep.readPathInstance handler match { // If the user entered an import, then just use it; add an import wrapping // level if the import might conflict with some other import @@ -157,6 +162,23 @@ trait Imports { code append (x.member + "\n") currentImps ++= x.importedNames + case x if isClassBased => + for (imv <- x.definedNames) { + if (!currentImps.contains(imv)) { + x match { + case _: ClassHandler => + code.append("import " + objName + req.accessPath + ".`" + imv + "`\n") + case _ => + val valName = req.lineRep.packageName + req.lineRep.readName + if (!tempValLines.contains(req.lineRep.lineId)) { + code.append(s"val $valName = $objName\n") + tempValLines += req.lineRep.lineId + } + code.append(s"import $valName${req.accessPath}.`$imv`;\n") + } + currentImps += imv + } + } // For other requests, import each defined name. // import them explicitly instead of with _, so that // ambiguity errors will not be generated. Also, quote |