Drop old null check optimizer
This commit is contained in:
Dmitry Petrov
+2
-2
@@ -21,7 +21,7 @@ import org.jetbrains.kotlin.codegen.optimization.boxing.RedundantBoxingMethodTra
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import org.jetbrains.kotlin.codegen.optimization.boxing.RedundantCoercionToUnitTransformer
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import org.jetbrains.kotlin.codegen.optimization.captured.CapturedVarsOptimizationMethodTransformer
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import org.jetbrains.kotlin.codegen.optimization.common.prepareForEmitting
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import org.jetbrains.kotlin.codegen.optimization.nullCheck.RedundantNullCheckV2MethodTransformer
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import org.jetbrains.kotlin.codegen.optimization.nullCheck.RedundantNullCheckMethodTransformer
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import org.jetbrains.kotlin.codegen.optimization.transformer.CompositeMethodTransformer
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import org.jetbrains.org.objectweb.asm.MethodVisitor
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import org.jetbrains.org.objectweb.asm.tree.MethodNode
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@@ -51,7 +51,7 @@ class OptimizationMethodVisitor(
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private val OPTIMIZATION_TRANSFORMER = CompositeMethodTransformer(
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CapturedVarsOptimizationMethodTransformer(),
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RedundantNullCheckV2MethodTransformer(),
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RedundantNullCheckMethodTransformer(),
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RedundantCheckCastEliminationMethodTransformer(),
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RedundantBoxingMethodTransformer(),
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RedundantCoercionToUnitTransformer(),
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+320
-50
@@ -16,82 +16,352 @@
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package org.jetbrains.kotlin.codegen.optimization.nullCheck
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import org.jetbrains.kotlin.codegen.coroutines.withInstructionAdapter
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import org.jetbrains.kotlin.codegen.inline.ReifiedTypeInliner
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import org.jetbrains.kotlin.codegen.optimization.DeadCodeEliminationMethodTransformer
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import org.jetbrains.kotlin.codegen.optimization.boxing.ProgressionIteratorBasicValue
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import org.jetbrains.kotlin.codegen.optimization.common.OptimizationBasicInterpreter
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import org.jetbrains.kotlin.codegen.optimization.common.isInsn
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import org.jetbrains.kotlin.codegen.optimization.fixStack.peek
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import org.jetbrains.kotlin.codegen.optimization.fixStack.top
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import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
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import org.jetbrains.kotlin.utils.SmartList
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import org.jetbrains.kotlin.utils.addToStdlib.safeAs
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import org.jetbrains.kotlin.utils.addToStdlib.assertedCast
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import org.jetbrains.org.objectweb.asm.Label
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import org.jetbrains.org.objectweb.asm.Opcodes
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import org.jetbrains.org.objectweb.asm.tree.InsnNode
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import org.jetbrains.org.objectweb.asm.tree.JumpInsnNode
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import org.jetbrains.org.objectweb.asm.tree.MethodNode
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import org.jetbrains.org.objectweb.asm.tree.analysis.BasicValue
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import org.jetbrains.org.objectweb.asm.Type
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import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
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import org.jetbrains.org.objectweb.asm.tree.*
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class RedundantNullCheckMethodTransformer : MethodTransformer() {
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private val deadCodeElimination = DeadCodeEliminationMethodTransformer()
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override fun transform(internalClassName: String, methodNode: MethodNode) {
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while (runSingleNullCheckEliminationPass(internalClassName, methodNode)) {
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deadCodeElimination.transform(internalClassName, methodNode)
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}
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while (TransformerPass(internalClassName, methodNode).run()) {}
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}
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private fun isAlwaysFalse(opcode: Int, nullability: Nullability) =
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(opcode == Opcodes.IFNULL && nullability == Nullability.NOT_NULL) ||
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(opcode == Opcodes.IFNONNULL && nullability == Nullability.NULL)
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private class TransformerPass(val internalClassName: String, val methodNode: MethodNode) {
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private var changes = false
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private fun isAlwaysTrue(opcode: Int, nullability: Nullability) =
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(opcode == Opcodes.IFNULL && nullability == Nullability.NULL) ||
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(opcode == Opcodes.IFNONNULL && nullability == Nullability.NOT_NULL)
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private fun AbstractInsnNode.getIndex() =
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methodNode.instructions.indexOf(this)
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fun run(): Boolean {
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val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode()
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eliminateRedundantChecks(checkedReferenceTypes)
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private fun runSingleNullCheckEliminationPass(internalClassName: String, methodNode: MethodNode): Boolean {
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val insnList = methodNode.instructions
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val instructions = insnList.toArray()
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val nullCheckIfs = instructions.mapNotNullTo(SmartList<JumpInsnNode>()) {
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it.safeAs<JumpInsnNode>()?.takeIf {
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it.opcode == Opcodes.IFNULL ||
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it.opcode == Opcodes.IFNONNULL
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}
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return changes
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}
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if (nullCheckIfs.isEmpty()) return false
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val frames = analyze(internalClassName, methodNode, NullabilityInterpreter())
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private fun analyzeTypesAndRemoveDeadCode(): Map<AbstractInsnNode, Type> {
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val insns = methodNode.instructions.toArray()
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val frames = analyze(internalClassName, methodNode, OptimizationBasicInterpreter())
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val redundantNullCheckIfs = nullCheckIfs.mapNotNull { insn ->
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frames[instructions.indexOf(insn)]?.top()?.let { top ->
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val nullability = top.getNullability()
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if (nullability == Nullability.NULLABLE)
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null
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else
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Pair(insn, nullability)
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val checkedReferenceTypes = HashMap<AbstractInsnNode, Type>()
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for (i in insns.indices) {
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val insn = insns[i]
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val frame = frames[i]
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if (insn.isInstanceOfOrNullCheck()) {
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checkedReferenceTypes[insn] = frame?.top()?.type ?: continue
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}
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else if (insn.isCheckParameterNotNull()) {
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checkedReferenceTypes[insn] = frame?.peek(1)?.type ?: continue
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}
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}
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val dceResult = DeadCodeEliminationMethodTransformer().removeDeadCodeByFrames(methodNode, frames)
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if (dceResult.hasRemovedAnything()) {
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changes = true
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}
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return checkedReferenceTypes
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}
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if (redundantNullCheckIfs.isEmpty()) return false
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for ((insn, nullability) in redundantNullCheckIfs) {
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val previous = insn.previous
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when (previous?.opcode) {
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Opcodes.ALOAD, Opcodes.DUP ->
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insnList.remove(previous)
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else ->
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insnList.insert(previous, InsnNode(Opcodes.POP))
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private fun eliminateRedundantChecks(checkedReferenceTypes: Map<AbstractInsnNode, Type>) {
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val nullabilityAssumptions = injectNullabilityAssumptions(checkedReferenceTypes)
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val nullabilityMap = analyzeNullabilities()
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nullabilityAssumptions.revert()
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transformTrivialChecks(nullabilityMap)
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}
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private fun injectNullabilityAssumptions(checkedReferenceTypes: Map<AbstractInsnNode, Type>) =
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NullabilityAssumptionsBuilder(checkedReferenceTypes).injectNullabilityAssumptions()
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private fun analyzeNullabilities(): Map<AbstractInsnNode, Nullability> {
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val frames = analyze(internalClassName, methodNode, NullabilityInterpreter())
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val insns = methodNode.instructions.toArray()
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val nullabilityMap = HashMap<AbstractInsnNode, Nullability>()
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for (i in insns.indices) {
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val nullability = frames[i]?.top()?.getNullability() ?: continue
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if (nullability == Nullability.NULLABLE) continue
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val insn = insns[i]
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if (insn.isInstanceOfOrNullCheck()) {
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nullabilityMap[insn] = nullability
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}
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}
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return nullabilityMap
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}
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when {
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isAlwaysTrue(insn.opcode, nullability) ->
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insnList.set(insn, JumpInsnNode(Opcodes.GOTO, insn.label))
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isAlwaysFalse(insn.opcode, nullability) ->
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insnList.remove(insn)
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private fun transformTrivialChecks(nullabilityMap: Map<AbstractInsnNode, Nullability>) {
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for ((insn, nullability) in nullabilityMap) {
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when (insn.opcode) {
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Opcodes.IFNULL -> transformTrivialNullJump(insn as JumpInsnNode, nullability == Nullability.NULL)
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Opcodes.IFNONNULL -> transformTrivialNullJump(insn as JumpInsnNode, nullability == Nullability.NOT_NULL)
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Opcodes.INSTANCEOF -> transformInstanceOf(insn, nullability)
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}
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}
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}
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return true
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private fun transformTrivialNullJump(insn: JumpInsnNode, alwaysTrue: Boolean) {
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changes = true
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methodNode.instructions.run {
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popReferenceValueBefore(insn)
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if (alwaysTrue) {
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set(insn, JumpInsnNode(Opcodes.GOTO, insn.label))
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}
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else {
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remove(insn)
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}
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}
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}
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private fun transformInstanceOf(insn: AbstractInsnNode, nullability: Nullability) {
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if (nullability != Nullability.NULL) return
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if (ReifiedTypeInliner.isOperationReifiedMarker(insn.previous)) return
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changes = true
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val nextOpcode = insn.next?.opcode
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if (nextOpcode == Opcodes.IFEQ || nextOpcode == Opcodes.IFNE)
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transformNullInstanceOfWithJump(insn)
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else
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transformNullInstanceOf(insn)
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}
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private fun transformNullInstanceOf(insn: AbstractInsnNode) {
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methodNode.instructions.run {
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popReferenceValueBefore(insn)
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set(insn, InsnNode(Opcodes.ICONST_0))
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}
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}
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private fun transformNullInstanceOfWithJump(insn: AbstractInsnNode) {
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methodNode.instructions.run {
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popReferenceValueBefore(insn)
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val jump = insn.next.assertedCast<JumpInsnNode> { "JumpInsnNode expected" }
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remove(insn)
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if (jump.opcode == Opcodes.IFEQ) {
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set(jump, JumpInsnNode(Opcodes.GOTO, jump.label))
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}
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else {
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remove(jump)
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}
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}
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}
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private inner class NullabilityAssumptionsBuilder(val checkedReferenceTypes: Map<AbstractInsnNode, Type>) {
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private val checksDependingOnVariable = HashMap<Int, MutableList<AbstractInsnNode>>()
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fun injectNullabilityAssumptions(): NullabilityAssumptions {
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collectVariableDependentChecks()
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return injectAssumptions()
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}
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private fun collectVariableDependentChecks() {
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for (insn in methodNode.instructions) {
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if (insn.isInstanceOfOrNullCheck()) {
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val previous = insn.previous ?: continue
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if (previous.opcode == Opcodes.ALOAD) {
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addDependentCheck(insn, previous as VarInsnNode)
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}
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else if (previous.opcode == Opcodes.DUP) {
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val previous2 = previous.previous ?: continue
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if (previous2.opcode == Opcodes.ALOAD) {
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addDependentCheck(insn, previous2 as VarInsnNode)
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}
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}
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}
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else if (insn.isCheckParameterNotNull()) {
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val ldcInsn = insn.previous ?: continue
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if (ldcInsn.opcode != Opcodes.LDC) continue
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val aLoadInsn = ldcInsn.previous ?: continue
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if (aLoadInsn.opcode != Opcodes.ALOAD) continue
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addDependentCheck(insn, aLoadInsn as VarInsnNode)
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}
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}
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}
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private fun addDependentCheck(insn: AbstractInsnNode, aLoadInsn: VarInsnNode) {
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checksDependingOnVariable.getOrPut(aLoadInsn.`var`) {
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SmartList<AbstractInsnNode>()
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}.add(insn)
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}
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private fun injectAssumptions(): NullabilityAssumptions {
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val nullabilityAssumptions = NullabilityAssumptions()
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for ((varIndex, dependentChecks) in checksDependingOnVariable) {
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for (checkInsn in dependentChecks) {
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val varType = checkedReferenceTypes[checkInsn]
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?: throw AssertionError("No var type @${checkInsn.getIndex()}")
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nullabilityAssumptions.injectAssumptionsForCheck(varIndex, checkInsn, varType)
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}
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}
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return nullabilityAssumptions
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}
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private fun NullabilityAssumptions.injectAssumptionsForCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
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when (insn.opcode) {
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Opcodes.IFNULL,
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Opcodes.IFNONNULL ->
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injectAssumptionsForNullCheck(varIndex, insn as JumpInsnNode, varType)
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Opcodes.INVOKESTATIC -> {
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assert(insn.isCheckParameterNotNull()) { "Expected non-null parameter check @${insn.getIndex()}"}
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injectAssumptionsForParameterNotNullCheck(varIndex, insn, varType)
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}
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Opcodes.INSTANCEOF ->
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injectAssumptionsForInstanceOfCheck(varIndex, insn, varType)
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}
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}
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private fun NullabilityAssumptions.injectAssumptionsForNullCheck(varIndex: Int, insn: JumpInsnNode, varType: Type) {
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// ALOAD v
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// IFNULL L
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// <...> -- v is not null here
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// L:
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// <...> -- v is null here
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val jumpsIfNull = insn.opcode == Opcodes.IFNULL
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val originalLabel = insn.label
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originalLabels[insn] = originalLabel
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insn.label = synthetic(LabelNode(Label()))
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val insertAfterNull = if (jumpsIfNull) insn.label else insn
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val insertAfterNonNull = if (jumpsIfNull) insn else insn.label
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methodNode.instructions.run {
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add(insn.label)
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insert(insertAfterNull, listOfSynthetics {
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aconst(null)
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store(varIndex, varType)
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if (jumpsIfNull) {
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goTo(originalLabel.label)
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}
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})
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insert(insertAfterNonNull, listOfSynthetics {
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anew(varType)
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store(varIndex, varType)
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if (!jumpsIfNull) {
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goTo(originalLabel.label)
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}
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})
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}
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}
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private fun NullabilityAssumptions.injectAssumptionsForParameterNotNullCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
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// ALOAD v
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// LDC param_name
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// INVOKESTATIC checkParameterIsNotNull
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// <...> -- v is not null here (otherwise an exception was thrown)
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methodNode.instructions.insert(insn, listOfSynthetics {
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anew(varType)
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store(varIndex, varType)
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})
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}
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private fun NullabilityAssumptions.injectAssumptionsForInstanceOfCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
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// ALOAD v
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// INSTANCEOF T
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// IFEQ L
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// <...> -- v is not null here (because it is an instance of T)
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// L:
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// <...> -- v is something else here (maybe null)
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val next = insn.next ?: return
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if (next.opcode != Opcodes.IFEQ && next.opcode != Opcodes.IFNE) return
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if (next !is JumpInsnNode) return
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val jumpsIfInstance = next.opcode == Opcodes.IFNE
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val originalLabel: LabelNode?
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val insertAfterNotNull: AbstractInsnNode
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if (jumpsIfInstance) {
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originalLabel = next.label
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originalLabels[next] = next.label
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val newLabel = synthetic(LabelNode(Label()))
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methodNode.instructions.add(newLabel)
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next.label = newLabel
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insertAfterNotNull = newLabel
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}
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else {
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originalLabel = null
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insertAfterNotNull = next
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}
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methodNode.instructions.run {
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insert(insertAfterNotNull, listOfSynthetics {
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anew(varType)
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store(varIndex, varType)
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if (originalLabel != null) {
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goTo(originalLabel.label)
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}
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})
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}
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}
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}
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inner class NullabilityAssumptions {
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val originalLabels = HashMap<JumpInsnNode, LabelNode>()
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val syntheticInstructions = ArrayList<AbstractInsnNode>()
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fun <T : AbstractInsnNode> synthetic(insn: T): T {
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syntheticInstructions.add(insn)
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return insn
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}
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inline fun listOfSynthetics(block: InstructionAdapter.() -> Unit): InsnList {
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val insnList = withInstructionAdapter(block)
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for (insn in insnList) {
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synthetic(insn)
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}
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return insnList
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}
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fun revert() {
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methodNode.instructions.run {
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syntheticInstructions.forEach { remove(it) }
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}
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for ((jumpInsn, originalLabel) in originalLabels) {
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jumpInsn.label = originalLabel
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}
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}
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}
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}
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||||
}
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internal fun AbstractInsnNode.isInstanceOfOrNullCheck() =
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opcode == Opcodes.INSTANCEOF || opcode == Opcodes.IFNULL || opcode == Opcodes.IFNONNULL
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internal fun AbstractInsnNode.isCheckParameterNotNull() =
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isInsn<MethodInsnNode>(Opcodes.INVOKESTATIC) {
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owner == "kotlin/jvm/internal/Intrinsics" &&
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name == "checkParameterIsNotNull" &&
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desc == "(Ljava/lang/Object;Ljava/lang/String;)V"
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}
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internal fun InsnList.popReferenceValueBefore(insn: AbstractInsnNode) {
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val prev = insn.previous
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when (prev?.opcode) {
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Opcodes.ACONST_NULL,
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||||
Opcodes.DUP,
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||||
Opcodes.ALOAD ->
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||||
remove(prev)
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else ->
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||||
insertBefore(insn, InsnNode(Opcodes.POP))
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}
|
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}
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-367
@@ -1,367 +0,0 @@
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/*
|
||||
* Copyright 2010-2017 JetBrains s.r.o.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package org.jetbrains.kotlin.codegen.optimization.nullCheck
|
||||
|
||||
import org.jetbrains.kotlin.codegen.coroutines.withInstructionAdapter
|
||||
import org.jetbrains.kotlin.codegen.inline.ReifiedTypeInliner
|
||||
import org.jetbrains.kotlin.codegen.optimization.DeadCodeEliminationMethodTransformer
|
||||
import org.jetbrains.kotlin.codegen.optimization.common.OptimizationBasicInterpreter
|
||||
import org.jetbrains.kotlin.codegen.optimization.common.isInsn
|
||||
import org.jetbrains.kotlin.codegen.optimization.fixStack.peek
|
||||
import org.jetbrains.kotlin.codegen.optimization.fixStack.top
|
||||
import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
|
||||
import org.jetbrains.kotlin.utils.SmartList
|
||||
import org.jetbrains.kotlin.utils.addToStdlib.assertedCast
|
||||
import org.jetbrains.org.objectweb.asm.Label
|
||||
import org.jetbrains.org.objectweb.asm.Opcodes
|
||||
import org.jetbrains.org.objectweb.asm.Type
|
||||
import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
|
||||
import org.jetbrains.org.objectweb.asm.tree.*
|
||||
|
||||
class RedundantNullCheckV2MethodTransformer : MethodTransformer() {
|
||||
override fun transform(internalClassName: String, methodNode: MethodNode) {
|
||||
while (TransformerPass(internalClassName, methodNode).run()) {}
|
||||
}
|
||||
|
||||
private class TransformerPass(val internalClassName: String, val methodNode: MethodNode) {
|
||||
private var changes = false
|
||||
|
||||
private fun AbstractInsnNode.getIndex() =
|
||||
methodNode.instructions.indexOf(this)
|
||||
|
||||
fun run(): Boolean {
|
||||
val checkedReferenceTypes = analyzeTypesAndRemoveDeadCode()
|
||||
eliminateRedundantChecks(checkedReferenceTypes)
|
||||
|
||||
return changes
|
||||
}
|
||||
|
||||
private fun analyzeTypesAndRemoveDeadCode(): Map<AbstractInsnNode, Type> {
|
||||
val insns = methodNode.instructions.toArray()
|
||||
val frames = analyze(internalClassName, methodNode, OptimizationBasicInterpreter())
|
||||
|
||||
val checkedReferenceTypes = HashMap<AbstractInsnNode, Type>()
|
||||
for (i in insns.indices) {
|
||||
val insn = insns[i]
|
||||
val frame = frames[i]
|
||||
if (insn.isInstanceOfOrNullCheck()) {
|
||||
checkedReferenceTypes[insn] = frame?.top()?.type ?: continue
|
||||
}
|
||||
else if (insn.isCheckParameterNotNull()) {
|
||||
checkedReferenceTypes[insn] = frame?.peek(1)?.type ?: continue
|
||||
}
|
||||
}
|
||||
|
||||
val dceResult = DeadCodeEliminationMethodTransformer().removeDeadCodeByFrames(methodNode, frames)
|
||||
if (dceResult.hasRemovedAnything()) {
|
||||
changes = true
|
||||
}
|
||||
|
||||
return checkedReferenceTypes
|
||||
}
|
||||
|
||||
private fun eliminateRedundantChecks(checkedReferenceTypes: Map<AbstractInsnNode, Type>) {
|
||||
val nullabilityAssumptions = injectNullabilityAssumptions(checkedReferenceTypes)
|
||||
|
||||
val nullabilityMap = analyzeNullabilities()
|
||||
|
||||
nullabilityAssumptions.revert()
|
||||
|
||||
transformTrivialChecks(nullabilityMap)
|
||||
}
|
||||
|
||||
private fun injectNullabilityAssumptions(checkedReferenceTypes: Map<AbstractInsnNode, Type>) =
|
||||
NullabilityAssumptionsBuilder(checkedReferenceTypes).injectNullabilityAssumptions()
|
||||
|
||||
private fun analyzeNullabilities(): Map<AbstractInsnNode, Nullability> {
|
||||
val frames = analyze(internalClassName, methodNode, NullabilityInterpreter())
|
||||
val insns = methodNode.instructions.toArray()
|
||||
val nullabilityMap = HashMap<AbstractInsnNode, Nullability>()
|
||||
for (i in insns.indices) {
|
||||
val nullability = frames[i]?.top()?.getNullability() ?: continue
|
||||
if (nullability == Nullability.NULLABLE) continue
|
||||
|
||||
val insn = insns[i]
|
||||
if (insn.isInstanceOfOrNullCheck()) {
|
||||
nullabilityMap[insn] = nullability
|
||||
}
|
||||
}
|
||||
return nullabilityMap
|
||||
}
|
||||
|
||||
private fun transformTrivialChecks(nullabilityMap: Map<AbstractInsnNode, Nullability>) {
|
||||
for ((insn, nullability) in nullabilityMap) {
|
||||
when (insn.opcode) {
|
||||
Opcodes.IFNULL -> transformTrivialNullJump(insn as JumpInsnNode, nullability == Nullability.NULL)
|
||||
Opcodes.IFNONNULL -> transformTrivialNullJump(insn as JumpInsnNode, nullability == Nullability.NOT_NULL)
|
||||
Opcodes.INSTANCEOF -> transformInstanceOf(insn, nullability)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private fun transformTrivialNullJump(insn: JumpInsnNode, alwaysTrue: Boolean) {
|
||||
changes = true
|
||||
|
||||
methodNode.instructions.run {
|
||||
popReferenceValueBefore(insn)
|
||||
if (alwaysTrue) {
|
||||
set(insn, JumpInsnNode(Opcodes.GOTO, insn.label))
|
||||
}
|
||||
else {
|
||||
remove(insn)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private fun transformInstanceOf(insn: AbstractInsnNode, nullability: Nullability) {
|
||||
if (nullability != Nullability.NULL) return
|
||||
if (ReifiedTypeInliner.isOperationReifiedMarker(insn.previous)) return
|
||||
|
||||
changes = true
|
||||
|
||||
val nextOpcode = insn.next?.opcode
|
||||
if (nextOpcode == Opcodes.IFEQ || nextOpcode == Opcodes.IFNE)
|
||||
transformNullInstanceOfWithJump(insn)
|
||||
else
|
||||
transformNullInstanceOf(insn)
|
||||
}
|
||||
|
||||
private fun transformNullInstanceOf(insn: AbstractInsnNode) {
|
||||
methodNode.instructions.run {
|
||||
popReferenceValueBefore(insn)
|
||||
set(insn, InsnNode(Opcodes.ICONST_0))
|
||||
}
|
||||
}
|
||||
|
||||
private fun transformNullInstanceOfWithJump(insn: AbstractInsnNode) {
|
||||
methodNode.instructions.run {
|
||||
popReferenceValueBefore(insn)
|
||||
val jump = insn.next.assertedCast<JumpInsnNode> { "JumpInsnNode expected" }
|
||||
remove(insn)
|
||||
if (jump.opcode == Opcodes.IFEQ) {
|
||||
set(jump, JumpInsnNode(Opcodes.GOTO, jump.label))
|
||||
}
|
||||
else {
|
||||
remove(jump)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private inner class NullabilityAssumptionsBuilder(val checkedReferenceTypes: Map<AbstractInsnNode, Type>) {
|
||||
|
||||
private val checksDependingOnVariable = HashMap<Int, MutableList<AbstractInsnNode>>()
|
||||
|
||||
fun injectNullabilityAssumptions(): NullabilityAssumptions {
|
||||
collectVariableDependentChecks()
|
||||
return injectAssumptions()
|
||||
}
|
||||
|
||||
private fun collectVariableDependentChecks() {
|
||||
for (insn in methodNode.instructions) {
|
||||
if (insn.isInstanceOfOrNullCheck()) {
|
||||
val previous = insn.previous ?: continue
|
||||
if (previous.opcode == Opcodes.ALOAD) {
|
||||
addDependentCheck(insn, previous as VarInsnNode)
|
||||
}
|
||||
else if (previous.opcode == Opcodes.DUP) {
|
||||
val previous2 = previous.previous ?: continue
|
||||
if (previous2.opcode == Opcodes.ALOAD) {
|
||||
addDependentCheck(insn, previous2 as VarInsnNode)
|
||||
}
|
||||
}
|
||||
}
|
||||
else if (insn.isCheckParameterNotNull()) {
|
||||
val ldcInsn = insn.previous ?: continue
|
||||
if (ldcInsn.opcode != Opcodes.LDC) continue
|
||||
val aLoadInsn = ldcInsn.previous ?: continue
|
||||
if (aLoadInsn.opcode != Opcodes.ALOAD) continue
|
||||
addDependentCheck(insn, aLoadInsn as VarInsnNode)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private fun addDependentCheck(insn: AbstractInsnNode, aLoadInsn: VarInsnNode) {
|
||||
checksDependingOnVariable.getOrPut(aLoadInsn.`var`) {
|
||||
SmartList<AbstractInsnNode>()
|
||||
}.add(insn)
|
||||
}
|
||||
|
||||
private fun injectAssumptions(): NullabilityAssumptions {
|
||||
val nullabilityAssumptions = NullabilityAssumptions()
|
||||
for ((varIndex, dependentChecks) in checksDependingOnVariable) {
|
||||
for (checkInsn in dependentChecks) {
|
||||
val varType = checkedReferenceTypes[checkInsn]
|
||||
?: throw AssertionError("No var type @${checkInsn.getIndex()}")
|
||||
nullabilityAssumptions.injectAssumptionsForCheck(varIndex, checkInsn, varType)
|
||||
}
|
||||
}
|
||||
return nullabilityAssumptions
|
||||
}
|
||||
|
||||
private fun NullabilityAssumptions.injectAssumptionsForCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
|
||||
when (insn.opcode) {
|
||||
Opcodes.IFNULL,
|
||||
Opcodes.IFNONNULL ->
|
||||
injectAssumptionsForNullCheck(varIndex, insn as JumpInsnNode, varType)
|
||||
Opcodes.INVOKESTATIC -> {
|
||||
assert(insn.isCheckParameterNotNull()) { "Expected non-null parameter check @${insn.getIndex()}"}
|
||||
injectAssumptionsForParameterNotNullCheck(varIndex, insn, varType)
|
||||
}
|
||||
Opcodes.INSTANCEOF ->
|
||||
injectAssumptionsForInstanceOfCheck(varIndex, insn, varType)
|
||||
}
|
||||
}
|
||||
|
||||
private fun NullabilityAssumptions.injectAssumptionsForNullCheck(varIndex: Int, insn: JumpInsnNode, varType: Type) {
|
||||
// ALOAD v
|
||||
// IFNULL L
|
||||
// <...> -- v is not null here
|
||||
// L:
|
||||
// <...> -- v is null here
|
||||
|
||||
val jumpsIfNull = insn.opcode == Opcodes.IFNULL
|
||||
val originalLabel = insn.label
|
||||
originalLabels[insn] = originalLabel
|
||||
insn.label = synthetic(LabelNode(Label()))
|
||||
|
||||
val insertAfterNull = if (jumpsIfNull) insn.label else insn
|
||||
val insertAfterNonNull = if (jumpsIfNull) insn else insn.label
|
||||
|
||||
methodNode.instructions.run {
|
||||
add(insn.label)
|
||||
|
||||
insert(insertAfterNull, listOfSynthetics {
|
||||
aconst(null)
|
||||
store(varIndex, varType)
|
||||
if (jumpsIfNull) {
|
||||
goTo(originalLabel.label)
|
||||
}
|
||||
})
|
||||
|
||||
insert(insertAfterNonNull, listOfSynthetics {
|
||||
anew(varType)
|
||||
store(varIndex, varType)
|
||||
if (!jumpsIfNull) {
|
||||
goTo(originalLabel.label)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
private fun NullabilityAssumptions.injectAssumptionsForParameterNotNullCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
|
||||
// ALOAD v
|
||||
// LDC param_name
|
||||
// INVOKESTATIC checkParameterIsNotNull
|
||||
// <...> -- v is not null here (otherwise an exception was thrown)
|
||||
|
||||
methodNode.instructions.insert(insn, listOfSynthetics {
|
||||
anew(varType)
|
||||
store(varIndex, varType)
|
||||
})
|
||||
}
|
||||
|
||||
private fun NullabilityAssumptions.injectAssumptionsForInstanceOfCheck(varIndex: Int, insn: AbstractInsnNode, varType: Type) {
|
||||
// ALOAD v
|
||||
// INSTANCEOF T
|
||||
// IFEQ L
|
||||
// <...> -- v is not null here (because it is an instance of T)
|
||||
// L:
|
||||
// <...> -- v is something else here (maybe null)
|
||||
|
||||
val next = insn.next ?: return
|
||||
if (next.opcode != Opcodes.IFEQ && next.opcode != Opcodes.IFNE) return
|
||||
if (next !is JumpInsnNode) return
|
||||
val jumpsIfInstance = next.opcode == Opcodes.IFNE
|
||||
|
||||
val originalLabel: LabelNode?
|
||||
val insertAfterNotNull: AbstractInsnNode
|
||||
if (jumpsIfInstance) {
|
||||
originalLabel = next.label
|
||||
originalLabels[next] = next.label
|
||||
val newLabel = synthetic(LabelNode(Label()))
|
||||
methodNode.instructions.add(newLabel)
|
||||
next.label = newLabel
|
||||
insertAfterNotNull = newLabel
|
||||
}
|
||||
else {
|
||||
originalLabel = null
|
||||
insertAfterNotNull = next
|
||||
}
|
||||
|
||||
methodNode.instructions.run {
|
||||
insert(insertAfterNotNull, listOfSynthetics {
|
||||
anew(varType)
|
||||
store(varIndex, varType)
|
||||
if (originalLabel != null) {
|
||||
goTo(originalLabel.label)
|
||||
}
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
inner class NullabilityAssumptions {
|
||||
val originalLabels = HashMap<JumpInsnNode, LabelNode>()
|
||||
val syntheticInstructions = ArrayList<AbstractInsnNode>()
|
||||
|
||||
fun <T : AbstractInsnNode> synthetic(insn: T): T {
|
||||
syntheticInstructions.add(insn)
|
||||
return insn
|
||||
}
|
||||
|
||||
inline fun listOfSynthetics(block: InstructionAdapter.() -> Unit): InsnList {
|
||||
val insnList = withInstructionAdapter(block)
|
||||
for (insn in insnList) {
|
||||
synthetic(insn)
|
||||
}
|
||||
return insnList
|
||||
}
|
||||
|
||||
fun revert() {
|
||||
methodNode.instructions.run {
|
||||
syntheticInstructions.forEach { remove(it) }
|
||||
}
|
||||
for ((jumpInsn, originalLabel) in originalLabels) {
|
||||
jumpInsn.label = originalLabel
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
internal fun AbstractInsnNode.isInstanceOfOrNullCheck() =
|
||||
opcode == Opcodes.INSTANCEOF || opcode == Opcodes.IFNULL || opcode == Opcodes.IFNONNULL
|
||||
|
||||
internal fun AbstractInsnNode.isCheckParameterNotNull() =
|
||||
isInsn<MethodInsnNode>(Opcodes.INVOKESTATIC) {
|
||||
owner == "kotlin/jvm/internal/Intrinsics" &&
|
||||
name == "checkParameterIsNotNull" &&
|
||||
desc == "(Ljava/lang/Object;Ljava/lang/String;)V"
|
||||
}
|
||||
|
||||
internal fun InsnList.popReferenceValueBefore(insn: AbstractInsnNode) {
|
||||
val prev = insn.previous
|
||||
when (prev?.opcode) {
|
||||
Opcodes.ACONST_NULL,
|
||||
Opcodes.DUP,
|
||||
Opcodes.ALOAD ->
|
||||
remove(prev)
|
||||
else ->
|
||||
insertBefore(insn, InsnNode(Opcodes.POP))
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user