org.jetbrains.kotlin.codegen.inline.InplaceArgumentsMethodTransformer.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
* Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
*/
package org.jetbrains.kotlin.codegen.inline
import org.jetbrains.kotlin.codegen.optimization.boxing.isMethodInsnWith
import org.jetbrains.kotlin.codegen.optimization.common.*
import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
import org.jetbrains.org.objectweb.asm.Opcodes
import org.jetbrains.org.objectweb.asm.tree.*
class InplaceArgumentsMethodTransformer : MethodTransformer() {
override fun transform(internalClassName: String, methodNode: MethodNode) {
val methodContext = parseMethodOrNull(methodNode)
if (methodContext != null) {
if (methodContext.calls.isEmpty()) return
collectStartToEnd(methodContext)
collectLvtEntryInstructions(methodContext)
collectSuspensionPoints(methodContext)
transformMethod(methodContext)
methodNode.fixupLVT()
methodNode.removeUnusedLocalVariables()
methodNode.updateMaxStack()
}
stripMarkers(methodNode)
}
private class MethodContext(
val methodNode: MethodNode,
val calls: List
) {
val startArgToEndArg = HashMap()
val lvtEntryForInstruction = HashMap()
val varInstructionMoved = HashMap()
val suspensionJumpLabels = HashSet()
}
private class CallContext(
val callStartMarker: AbstractInsnNode,
val callEndMarker: AbstractInsnNode,
val args: List,
val calls: List,
)
private class ArgContext(
val argStartMarker: AbstractInsnNode,
val argEndMarker: AbstractInsnNode,
val calls: List,
val storeInsn: VarInsnNode?
) {
val loadOpcode =
if (storeInsn != null)
storeInsn.opcode - Opcodes.ISTORE + Opcodes.ILOAD
else
-1
val varIndex = storeInsn?.`var` ?: -1
}
private fun parseMethodOrNull(methodNode: MethodNode): MethodContext? {
// We assume that the method body structure follows this grammar:
// METHOD ::= insn* (CALL insn*)*
// CALL ::= callStartMarker insn* (ARG insn*)* (CALL insn*)* callEndMarker
// ARG ::= argStartMarker insn* (CALL insn*)* argEndMarker storeInsn
val iter = methodNode.instructions.iterator()
val calls = ArrayList()
try {
while (iter.hasNext()) {
val insn = iter.next()
when {
insn.isInplaceCallStartMarker() ->
calls.add(parseCall(methodNode, insn, iter))
insn.isInplaceCallEndMarker() || insn.isInplaceArgumentStartMarker() || insn.isInplaceArgumentEndMarker() ->
throw ParseErrorException()
}
}
} catch (e: ParseErrorException) {
return null
}
return MethodContext(methodNode, calls)
}
private fun parseCall(methodNode: MethodNode, start: AbstractInsnNode, iter: ListIterator): CallContext {
// CALL ::= callStartMarker insn* (ARG insn*)* (CALL insn*)* callEndMarker
val args = ArrayList()
val calls = ArrayList()
while (iter.hasNext()) {
val insn = iter.next()
when {
insn.isInplaceCallStartMarker() ->
calls.add(parseCall(methodNode, insn, iter))
insn.isInplaceCallEndMarker() ->
return CallContext(start, insn, args, calls)
insn.isInplaceArgumentStartMarker() ->
args.add(parseArg(methodNode, insn, iter))
insn.isInplaceArgumentEndMarker() ->
throw ParseErrorException()
}
}
// Reached instruction list end, didn't find inplace-call-end marker
throw ParseErrorException()
}
private fun parseArg(methodNode: MethodNode, start: AbstractInsnNode, iter: ListIterator): ArgContext {
// ARG ::= argStartMarker insn* (CALL insn*)* argEndMarker storeInsn
val calls = ArrayList()
while (iter.hasNext()) {
val insn = iter.next()
when {
insn.isInplaceCallStartMarker() ->
calls.add(parseCall(methodNode, insn, iter))
insn.isInplaceArgumentEndMarker() -> {
val next = insn.next
return when {
next is VarInsnNode && next.opcode in Opcodes.ISTORE..Opcodes.ASTORE -> {
iter.next()
ArgContext(start, insn, calls, next)
}
insn.previous.isInplaceArgumentStartMarker() -> {
// Empty argument - a remapped variable.
// For such argument varIndex would be '-1', so it would not be associated with any LOAD instruction.
ArgContext(start, insn, calls, null)
}
else -> {
throw ParseErrorException()
}
}
}
insn.isInplaceCallEndMarker() || insn.isInplaceArgumentStartMarker() ->
throw ParseErrorException()
}
}
// Reached instruction list end, didn't find inplace-argument-end marker
throw ParseErrorException()
}
private class ParseErrorException : RuntimeException() {
override fun fillInStackTrace(): Throwable = this
}
private fun collectStartToEnd(methodContext: MethodContext) {
for (call in methodContext.calls) {
collectStartToEnd(methodContext, call)
}
}
private fun collectStartToEnd(methodContext: MethodContext, callContext: CallContext) {
for (arg in callContext.args) {
collectStartToEnd(methodContext, arg)
}
for (call in callContext.calls) {
collectStartToEnd(methodContext, call)
}
}
private fun collectStartToEnd(methodContext: MethodContext, argContext: ArgContext) {
methodContext.startArgToEndArg[argContext.argStartMarker] = argContext.argEndMarker
for (call in argContext.calls) {
collectStartToEnd(methodContext, call)
}
}
private fun collectLvtEntryInstructions(methodContext: MethodContext) {
val insnList = methodContext.methodNode.instructions
val insnArray = insnList.toArray()
for (lv in methodContext.methodNode.localVariables) {
val lvStartIndex = insnList.indexOf(lv.start)
val lvEndIndex = insnList.indexOf(lv.end)
for (i in lvStartIndex until lvEndIndex) {
val insn = insnArray[i]
if (insn.opcode in Opcodes.ILOAD..Opcodes.ALOAD || insn.opcode in Opcodes.ISTORE..Opcodes.ASTORE) {
if ((insn as VarInsnNode).`var` == lv.index) {
methodContext.lvtEntryForInstruction[insn] = lv
}
} else if (insn.opcode == Opcodes.IINC) {
if ((insn as IincInsnNode).`var` == lv.index) {
methodContext.lvtEntryForInstruction[insn] = lv
}
}
}
}
}
private fun collectSuspensionPoints(methodContext: MethodContext) {
val insnList = methodContext.methodNode.instructions
var insn = insnList.first
while (
!insn.isMethodInsnWith(Opcodes.INVOKESTATIC) {
owner == "kotlin/coroutines/intrinsics/IntrinsicsKt" &&
name == "getCOROUTINE_SUSPENDED" &&
desc == "()Ljava/lang/Object;"
}
) {
insn = insn.next ?: return
}
// Find a first TABLESWITCH and record its jump destinations
while (insn != null) {
if (insn.opcode != Opcodes.TABLESWITCH || insn.previous.opcode != Opcodes.GETFIELD) {
insn = insn.next
continue
}
val getFiendInsn = insn.previous as FieldInsnNode
if (getFiendInsn.name != "label" || getFiendInsn.desc != "I") {
insn = insn.next
continue
}
val tableSwitchInsn = insn as TableSwitchInsnNode
methodContext.suspensionJumpLabels.addAll(tableSwitchInsn.labels)
methodContext.suspensionJumpLabels.add(tableSwitchInsn.dflt)
return
}
}
private fun transformMethod(methodContext: MethodContext) {
for (call in methodContext.calls) {
transformCall(methodContext, call)
}
}
private fun transformCall(methodContext: MethodContext, callContext: CallContext) {
// Transform nested calls
for (arg in callContext.args) {
for (nestedCall in arg.calls) {
transformCall(methodContext, nestedCall)
}
}
for (call in callContext.calls) {
transformCall(methodContext, call)
}
if (callContext.args.any { it.isUnsafeToMove(methodContext) }) {
// Do not transform such call, just strip call and argument markers.
val insnList = methodContext.methodNode.instructions
for (arg in callContext.args) {
insnList.remove(arg.argStartMarker)
insnList.remove(arg.argEndMarker)
}
insnList.remove(callContext.callStartMarker)
insnList.remove(callContext.callEndMarker)
return
}
moveInplaceArgumentsFromStoresToLoads(methodContext, callContext)
}
private fun ArgContext.isUnsafeToMove(methodContext: MethodContext): Boolean {
// The following operations make inplace argument unsafe to move:
// - non-local jump (moving such argument inside inline function body can interfere with stack normalization);
// - variable store (variables defined inside argument can interfere with variables in inline function body).
// TODO investigate whether it's possible to lift these restrictions.
val argInsns = InsnSequence(this.argStartMarker, this.argEndMarker)
val localLabels = argInsns.filterTo(HashSet()) { it is LabelNode }
return argInsns.any { insn ->
insn.isStoreOperation() ||
insn in methodContext.suspensionJumpLabels ||
insn.opcode == Opcodes.GOTO && (insn as JumpInsnNode).label !in localLabels
}
}
private fun moveInplaceArgumentsFromStoresToLoads(methodContext: MethodContext, callContext: CallContext) {
// Transform call
val insnList = methodContext.methodNode.instructions
val args = callContext.args.associateBy { it.varIndex }
var argsProcessed = 0
var insn: AbstractInsnNode = callContext.callStartMarker
while (insn != callContext.callEndMarker) {
when {
insn.isInplaceArgumentStartMarker() -> {
// Skip argument body
insn = methodContext.startArgToEndArg[insn]!!
}
insn.opcode in Opcodes.ILOAD..Opcodes.ALOAD -> {
// Load instruction
val loadInsn = insn as VarInsnNode
val varIndex = loadInsn.`var`
val arg = args[varIndex]
if (arg == null || arg.loadOpcode != insn.opcode) {
// Not an argument load
insn = insn.next
} else {
// For each argument within this call we have
//
//
//
// store [arg]
// ...
// load [arg]
// Replace 'load [arg]' with '', drop 'store [arg]' and argument markers.
var argInsn = arg.argStartMarker.next
while (argInsn != arg.argEndMarker) {
// If a LOAD/STORE/IINC instruction was moved,
// record it so that we can update corresponding LVT entry if needed.
// NB it's better to do so after all transformations, so that we don't recalculate node indices.
if (argInsn.opcode in Opcodes.ILOAD..Opcodes.ALOAD ||
argInsn.opcode in Opcodes.ISTORE..Opcodes.ASTORE ||
argInsn.opcode == Opcodes.IINC
) {
methodContext.varInstructionMoved[argInsn] = callContext
}
val argInsnNext = argInsn.next
insnList.remove(argInsn)
insnList.insertBefore(loadInsn, argInsn)
argInsn = argInsnNext
}
// Remove argument load and corresponding argument store instructions
insnList.remove(arg.storeInsn)
insn = loadInsn.next
insnList.remove(loadInsn)
// Replace subsequent argument loads with DUP instructions of appropriate size
while (insn.opcode == loadInsn.opcode && (insn as VarInsnNode).`var` == varIndex) {
if (insn.opcode == Opcodes.LLOAD || insn.opcode == Opcodes.DLOAD) {
insnList.insertBefore(insn, InsnNode(Opcodes.DUP2))
} else {
insnList.insertBefore(insn, InsnNode(Opcodes.DUP))
}
val next = insn.next
insnList.remove(insn)
insn = next
}
// Remove argument markers
insnList.remove(arg.argStartMarker)
insnList.remove(arg.argEndMarker)
// If there are no more inplace arguments left to process, we are done
++argsProcessed
if (argsProcessed >= callContext.args.size)
break
}
}
else ->
insn = insn.next
}
}
// Remove call start and call end markers
insnList.remove(callContext.callStartMarker)
insnList.remove(callContext.callEndMarker)
}
private fun stripMarkers(methodNode: MethodNode) {
var insn = methodNode.instructions.first
while (insn != null) {
if (insn.isInplaceCallStartMarker() ||
insn.isInplaceCallEndMarker() ||
insn.isInplaceArgumentStartMarker() ||
insn.isInplaceArgumentEndMarker()
) {
val next = insn.next
methodNode.instructions.remove(insn)
insn = next
continue
}
insn = insn.next
}
}
}
// HACK: if new end label is before start label, change to the next one
private fun MethodNode.fixupLVT() {
for (localVariable in localVariables) {
val startIndex = instructions.indexOf(localVariable.start)
val endIndex = instructions.indexOf(localVariable.end)
if (endIndex < startIndex) {
val newEnd = localVariable.start.findNextOrNull { it is LabelNode } as? LabelNode
localVariable.end = newEnd ?: localVariable.start
}
}
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