org.jetbrains.kotlin.codegen.forLoop.IteratorForLoopGenerator.kt Maven / Gradle / Ivy

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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.forLoop

import org.jetbrains.kotlin.codegen.ExpressionCodegen
import org.jetbrains.kotlin.codegen.StackValue
import org.jetbrains.kotlin.descriptors.FunctionDescriptor
import org.jetbrains.kotlin.diagnostics.DiagnosticUtils
import org.jetbrains.kotlin.psi.KtForExpression
import org.jetbrains.kotlin.resolve.BindingContext.*
import org.jetbrains.kotlin.resolve.BindingContextUtils.getNotNull
import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
import org.jetbrains.kotlin.resolve.scopes.receivers.TransientReceiver
import org.jetbrains.org.objectweb.asm.Label
import org.jetbrains.org.objectweb.asm.Type

class IteratorForLoopGenerator(codegen: ExpressionCodegen, forExpression: KtForExpression)
    : AbstractForLoopGenerator(codegen, forExpression)
{
    private var iteratorVarIndex: Int = 0
    private val iteratorCall: ResolvedCall
    private val nextCall: ResolvedCall
    private val asmTypeForIterator: Type

    init {
        val loopRange = forExpression.loopRange!!
        this.iteratorCall = getNotNull(bindingContext,
                                       LOOP_RANGE_ITERATOR_RESOLVED_CALL, loopRange,
                                       "No .iterator() function " + DiagnosticUtils.atLocation(loopRange))

        val iteratorType = iteratorCall.resultingDescriptor.returnType!!
        this.asmTypeForIterator = codegen.asmType(iteratorType)

        this.nextCall = getNotNull(bindingContext,
                                   LOOP_RANGE_NEXT_RESOLVED_CALL, loopRange,
                                   "No next() function " + DiagnosticUtils.atLocation(loopRange))
    }

    override fun beforeLoop() {
        super.beforeLoop()

        // Iterator tmp = c.iterator()
        iteratorVarIndex = createLoopTempVariable(asmTypeForIterator)
        StackValue.local(iteratorVarIndex, asmTypeForIterator).store(codegen.invokeFunction(iteratorCall, StackValue.none()), v)
    }

    override fun checkEmptyLoop(loopExit: Label) {}

    override fun checkPreCondition(loopExit: Label) {
        // tmp.hasNext()

        val loopRange = forExpression.loopRange
        val hasNextCall = getNotNull(
                codegen.bindingContext, LOOP_RANGE_HAS_NEXT_RESOLVED_CALL,
                loopRange!!,
                "No hasNext() function " + DiagnosticUtils.atLocation(loopRange)
        )
        val fakeCall = codegen.makeFakeCall(TransientReceiver(iteratorCall.resultingDescriptor.returnType!!))
        val result = codegen.invokeFunction(fakeCall, hasNextCall, StackValue.local(iteratorVarIndex, asmTypeForIterator))
        result.put(Type.BOOLEAN_TYPE, v)

        v.ifeq(loopExit)
    }

    override fun assignToLoopParameter() {
        val fakeCall = codegen.makeFakeCall(TransientReceiver(iteratorCall.resultingDescriptor.returnType!!))
        val value = codegen.invokeFunction(fakeCall, nextCall, StackValue.local(iteratorVarIndex, asmTypeForIterator))

        StackValue.local(loopParameterVar, loopParameterType).store(value, v)
    }

    override fun checkPostConditionAndIncrement(loopExit: Label) {}
}