/*
* 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.range.forLoop
import org.jetbrains.kotlin.codegen.ExpressionCodegen
import org.jetbrains.kotlin.codegen.StackValue
import org.jetbrains.kotlin.psi.KtForExpression
import org.jetbrains.kotlin.types.KotlinType
import org.jetbrains.org.objectweb.asm.Label
import org.jetbrains.org.objectweb.asm.Type
import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
class ForInCharSequenceLoopGenerator(
codegen: ExpressionCodegen,
forExpression: KtForExpression,
private val canCacheLength: Boolean,
private val charSequenceClassType: Type?
) : AbstractForLoopGenerator(codegen, forExpression) {
private var indexVar: Int = 0
private var charSequenceVar: Int = 0
private var charSequenceLengthVar: Int = 0
private val charSequenceType = charSequenceClassType ?: CHAR_SEQUENCE_TYPE
override fun beforeLoop() {
super.beforeLoop()
indexVar = createLoopTempVariable(Type.INT_TYPE)
val loopRange = forExpression.loopRange
val value = codegen.gen(loopRange)
val loopRangeType: KotlinType = bindingContext.getType(forExpression.loopRange!!)!!
val asmLoopRangeType = codegen.asmType(loopRangeType)
// NB even if we already have a loop range stored in local variable, that variable might be modified in the loop body
// (see controlStructures/forInCharSequenceMut.kt).
// We should always store the corresponding CharSequence to a local variable to preserve the Iterator-based behavior.
charSequenceVar = createLoopTempVariable(charSequenceType)
value.put(asmLoopRangeType, loopRangeType, v)
v.store(charSequenceVar, charSequenceType)
if (canCacheLength) {
charSequenceLengthVar = createLoopTempVariable(Type.INT_TYPE)
v.load(charSequenceVar, charSequenceType)
v.invokeCharSequenceMethod("length", "()I")
v.store(charSequenceLengthVar, Type.INT_TYPE)
}
v.iconst(0)
v.store(indexVar, Type.INT_TYPE)
}
override fun checkEmptyLoop(loopExit: Label) {}
override fun checkPreCondition(loopExit: Label) {
v.load(indexVar, Type.INT_TYPE)
if (canCacheLength) {
v.load(charSequenceLengthVar, Type.INT_TYPE)
} else {
v.load(charSequenceVar, charSequenceType)
v.invokeCharSequenceMethod("length", "()I")
}
v.ificmpge(loopExit)
}
override fun assignToLoopParameter() {
v.load(charSequenceVar, charSequenceType)
v.load(indexVar, Type.INT_TYPE)
v.invokeCharSequenceMethod("charAt", "(I)C")
StackValue.onStack(Type.CHAR_TYPE).put(asmElementType, elementType, codegen.v)
v.store(loopParameterVar, asmElementType)
}
override fun checkPostConditionAndIncrement(loopExit: Label) {
v.iinc(indexVar, 1)
}
private fun InstructionAdapter.invokeCharSequenceMethod(name: String, desc: String) {
val charSequenceClassType = charSequenceClassType
if (charSequenceClassType != null) {
invokevirtual(charSequenceClassType.internalName, name, desc, false)
} else {
invokeinterface(CHAR_SEQUENCE_TYPE.internalName, name, desc)
}
}
companion object {
val CHAR_SEQUENCE_TYPE: Type = Type.getObjectType("java/lang/CharSequence")
}
}