org.jetbrains.kotlin.js.inline.util.rewriters.ReturnReplacingVisitor.kt Maven / Gradle / Ivy
/*
* 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.js.inline.util.rewriters
import org.jetbrains.kotlin.js.backend.ast.*
import org.jetbrains.kotlin.js.backend.ast.metadata.*
import org.jetbrains.kotlin.js.translate.context.Namer
import org.jetbrains.kotlin.js.translate.utils.JsAstUtils
class ReturnReplacingVisitor(
private val resultRef: JsNameRef?,
private val breakLabel: JsNameRef?,
private val function: JsFunction,
private val isSuspend: Boolean
) : JsVisitorWithContextImpl() {
/**
* Prevents replacing returns in object literal
*/
override fun visit(x: JsObjectLiteral, ctx: JsContext): Boolean = false
/**
* Prevents replacing returns in inner function
*/
override fun visit(x: JsFunction, ctx: JsContext): Boolean = false
override fun endVisit(x: JsReturn, ctx: JsContext) {
if (x.returnTarget != null && function.functionDescriptor != x.returnTarget) return
ctx.removeMe()
val returnExpression = x.expression
val returnReplacement = getReturnReplacement(x.expression)
if (returnReplacement != null) {
if (returnExpression != null && returnExpression.isTailCallSuspend) {
returnReplacement.isSuspend = true
}
ctx.addNext(JsExpressionStatement(returnReplacement.apply { source = x.source }))
}
if (breakLabel != null) {
ctx.addNext(JsBreak(breakLabel).apply { source = x.source })
}
}
private fun getReturnReplacement(returnExpression: JsExpression?): JsExpression? {
return if (returnExpression != null) {
val assignment = resultRef?.let { lhs ->
val rhs = processCoroutineResult(returnExpression)!!
JsAstUtils.assignment(lhs, rhs).apply { synthetic = true }
}
assignment ?: processCoroutineResult(returnExpression)
}
else {
processCoroutineResult(null)
}
}
fun processCoroutineResult(expression: JsExpression?): JsExpression? {
if (!isSuspend) return expression
if (expression != null && expression.isTailCallSuspend) return expression
val lhs = JsNameRef("\$\$coroutineResult\$\$", JsAstUtils.stateMachineReceiver()).apply { coroutineResult = true }
return JsAstUtils.assignment(lhs, expression ?: Namer.getUndefinedExpression())
}
}