org.jetbrains.kotlin.codegen.optimization.fixStack.AnalyzeTryCatchBlocks.kt Maven / Gradle / Ivy

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/*
 * Copyright 2010-2015 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.fixStack

import com.sun.xml.internal.ws.org.objectweb.asm.Opcodes
import org.jetbrains.kotlin.codegen.optimization.common.findNextOrNull
import org.jetbrains.kotlin.codegen.optimization.common.hasOpcode
import org.jetbrains.kotlin.codegen.optimization.transformer.MethodTransformer
import org.jetbrains.kotlin.codegen.pseudoInsns.PseudoInsn
import org.jetbrains.org.objectweb.asm.Label
import org.jetbrains.org.objectweb.asm.tree.*
import org.jetbrains.org.objectweb.asm.util.Printer
import java.util.*

private class DecompiledTryDescriptor(val tryStartLabel: LabelNode) {
    var defaultHandlerTcb : TryCatchBlockNode? = null
    val handlerStartLabels = hashSetOf()
}

private fun TryCatchBlockNode.isDefaultHandlerNode(): Boolean =
        start == handler

private fun MethodNode.debugString(tcb: TryCatchBlockNode): String =
        "TCB<${instructions.indexOf(tcb.start)}, ${instructions.indexOf(tcb.end)}, ${instructions.indexOf(tcb.handler)}>"

internal fun insertTryCatchBlocksMarkers(methodNode: MethodNode) {
    if (methodNode.tryCatchBlocks.isEmpty()) return

    val decompiledTryDescriptorForStart = linkedMapOf()
    val decompiledTryDescriptorForHandler = hashMapOf()

    collectDecompiledTryDescriptors(decompiledTryDescriptorForStart, decompiledTryDescriptorForHandler, methodNode)


    val newTryStartLabels = hashMapOf()

    insertSaveRestoreStackMarkers(decompiledTryDescriptorForStart, methodNode, newTryStartLabels)

    transformTryCatchBlocks(methodNode, newTryStartLabels)
}

private fun transformTryCatchBlocks(methodNode: MethodNode, newTryStartLabels: HashMap) {
    methodNode.tryCatchBlocks = methodNode.tryCatchBlocks.map { tcb ->
        val newTryStartLabel = newTryStartLabels[tcb.start]
        if (newTryStartLabel == null)
            tcb
        else
            TryCatchBlockNode(newTryStartLabel, tcb.end, tcb.handler, tcb.type)
    }
}

private fun insertSaveRestoreStackMarkers(
        decompiledTryDescriptorForStart: Map,
        methodNode: MethodNode,
        newTryStartLabels: MutableMap
) {
    val doneTryStartLabels = hashSetOf()
    val doneHandlerLabels = hashSetOf()

    for (decompiledTryDescriptor in decompiledTryDescriptorForStart.values) {
        with(decompiledTryDescriptor) {
            if (!doneTryStartLabels.contains(tryStartLabel)) {
                doneTryStartLabels.add(tryStartLabel)

                val nopNode = tryStartLabel.findNextOrNull { it.hasOpcode() }!!
                assert(nopNode.getOpcode() == Opcodes.NOP) { "${methodNode.instructions.indexOf(nopNode)}: try block should start with NOP" }

                val newTryStartLabel = LabelNode(Label())
                newTryStartLabels[tryStartLabel] = newTryStartLabel

                methodNode.instructions.insertBefore(nopNode, PseudoInsn.SAVE_STACK_BEFORE_TRY.createInsnNode())
                methodNode.instructions.insertBefore(nopNode, newTryStartLabel)
                methodNode.instructions.insert(nopNode, PseudoInsn.RESTORE_STACK_IN_TRY_CATCH.createInsnNode())
            }

            for (handlerStartLabel in handlerStartLabels) {
                if (!doneHandlerLabels.contains(handlerStartLabel)) {
                    doneHandlerLabels.add(handlerStartLabel)

                    val storeNode = handlerStartLabel.findNextOrNull { it.hasOpcode() }!!
                    assert(storeNode.getOpcode() == Opcodes.ASTORE) { "${methodNode.instructions.indexOf(storeNode)}: handler should start with ASTORE" }

                    methodNode.instructions.insert(storeNode, PseudoInsn.RESTORE_STACK_IN_TRY_CATCH.createInsnNode())
                }
            }
        }
    }
}

private fun collectDecompiledTryDescriptors(
        decompiledTryDescriptorForStart: MutableMap,
        decompiledTryDescriptorForHandler: MutableMap,
        methodNode: MethodNode
) {
    for (tcb in methodNode.tryCatchBlocks) {
        if (tcb.isDefaultHandlerNode()) {
            assert(decompiledTryDescriptorForHandler.containsKey(tcb.start)) { "${methodNode.debugString(tcb)}: default handler should occur after some regular handler" }
        }

        val decompiledTryDescriptor = decompiledTryDescriptorForHandler.getOrPut(tcb.handler) {
            decompiledTryDescriptorForStart.getOrPut(tcb.start) {
                DecompiledTryDescriptor(tcb.start)
            }
        }
        with(decompiledTryDescriptor) {
            handlerStartLabels.add(tcb.handler)

            if (tcb.isDefaultHandlerNode()) {
                assert(defaultHandlerTcb == null) {
                    "${methodNode.debugString(tcb)}: default handler is already found: ${methodNode.debugString(defaultHandlerTcb!!)}"
                }

                defaultHandlerTcb = tcb
            }
        }
    }
}