org.jetbrains.kotlin.backend.jvm.lower.RemoveDuplicatedInlinedLocalClassesLowering.kt Maven / Gradle / Ivy
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/*
* Copyright 2010-2022 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.backend.jvm.lower
import org.jetbrains.kotlin.backend.common.FileLoweringPass
import org.jetbrains.kotlin.backend.common.ir.getDefaultAdditionalStatementsFromInlinedBlock
import org.jetbrains.kotlin.backend.common.ir.getNonDefaultAdditionalStatementsFromInlinedBlock
import org.jetbrains.kotlin.backend.common.ir.getOriginalStatementsFromInlinedBlock
import org.jetbrains.kotlin.backend.common.lower.LocalDeclarationsLowering
import org.jetbrains.kotlin.ir.util.parents
import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
import org.jetbrains.kotlin.backend.jvm.*
import org.jetbrains.kotlin.ir.IrElement
import org.jetbrains.kotlin.ir.IrStatement
import org.jetbrains.kotlin.ir.declarations.IrClass
import org.jetbrains.kotlin.ir.declarations.IrFile
import org.jetbrains.kotlin.ir.declarations.IrFunction
import org.jetbrains.kotlin.ir.expressions.*
import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
import org.jetbrains.kotlin.ir.expressions.impl.IrConstructorCallImpl
import org.jetbrains.kotlin.ir.util.*
import org.jetbrains.kotlin.ir.visitors.IrElementTransformer
import org.jetbrains.kotlin.name.NameUtils
internal val removeDuplicatedInlinedLocalClasses = makeIrFilePhase(
{ context ->
if (!context.irInlinerIsEnabled()) return@makeIrFilePhase FileLoweringPass.Empty
RemoveDuplicatedInlinedLocalClassesLowering(context)
},
name = "RemoveDuplicatedInlinedLocalClasses",
description = "Drop excess local classes that were copied by ir inliner",
prerequisite = setOf(functionInliningPhase, localDeclarationsPhase)
)
private data class Data(
var classDeclaredOnCallSiteOrIsDefaultLambda: Boolean = false,
var insideInlineBlock: Boolean = false,
var modifyTree: Boolean = true,
)
// There are three types of inlined local classes:
// 1. MUST BE regenerated according to set of rules in AnonymousObjectTransformationInfo.
// They all have `originalBeforeInline != null`.
// 2. MUST NOT BE regenerated and MUST BE CREATED only once because they are copied from call site, for example, from lambda.
// This lambda will not exist after inline, so we copy declaration into new temporary inline call `singleArgumentInlineFunction`.
// 3. MUST NOT BE created at all because will be created at callee site.
// This lowering drops declarations that correspond to second and third type.
private class RemoveDuplicatedInlinedLocalClassesLowering(val context: JvmBackendContext) : IrElementTransformer, FileLoweringPass {
private val visited = mutableSetOf()
private val capturedConstructors = context.mapping.capturedConstructors
private fun removeUselessDeclarationsFromCapturedConstructors(irClass: IrClass, data: Data) {
irClass.parents.first { it !is IrFunction || it.origin != JvmLoweredDeclarationOrigin.INLINE_LAMBDA }
.accept(this, data.copy(classDeclaredOnCallSiteOrIsDefaultLambda = false, modifyTree = false))
}
override fun lower(irFile: IrFile) {
irFile.transformChildren(this, Data())
}
override fun visitCall(expression: IrCall, data: Data): IrElement {
if (expression.symbol == context.ir.symbols.singleArgumentInlineFunction) return expression
return super.visitCall(expression, data)
}
override fun visitBlock(expression: IrBlock, data: Data): IrExpression {
if (expression is IrInlinedFunctionBlock) {
val newData = data.copy(insideInlineBlock = true)
expression.getNonDefaultAdditionalStatementsFromInlinedBlock()
.forEach { it.transform(this, newData.copy(classDeclaredOnCallSiteOrIsDefaultLambda = false)) }
expression.getDefaultAdditionalStatementsFromInlinedBlock()
.forEach { it.transform(this, newData.copy(classDeclaredOnCallSiteOrIsDefaultLambda = true)) }
expression.getOriginalStatementsFromInlinedBlock()
.forEach { it.transform(this, newData.copy(classDeclaredOnCallSiteOrIsDefaultLambda = true)) }
return expression
}
val anonymousClass = expression.statements.firstOrNull()
val result = super.visitBlock(expression, data)
if (anonymousClass is IrClass && result is IrBlock && result.statements.firstOrNull() is IrComposite) {
reuseConstructorFromOriginalClass(result, anonymousClass, data)
}
return result
}
private fun reuseConstructorFromOriginalClass(block: IrBlock, anonymousClass: IrClass, data: Data) {
val lastStatement = block.statements.last()
val constructorCall = (lastStatement as? IrConstructorCall)
?: (lastStatement as IrBlock).statements.last() as IrConstructorCall
val constructorParent = constructorCall.symbol.owner.parentAsClass
// It is possible that inlined class will be lowered before original. In that case we must launch `LocalDeclarationsLowering` and
// lower original declaration to get correct captured constructor.
val container = anonymousClass.attributeOwnerId.extractRelatedDeclaration()?.parents
?.filterIsInstance()?.firstOrNull()?.takeIf { it.body != null }
container?.let {
LocalDeclarationsLowering(
context, NameUtils::sanitizeAsJavaIdentifier, JvmVisibilityPolicy(),
compatibilityModeForInlinedLocalDelegatedPropertyAccessors = true, forceFieldsForInlineCaptures = true
).lowerWithoutActualChange(it.body!!, it)
}
// We must remove all constructors from `capturedConstructors` that belong to the classes that will be removed
capturedConstructors.keys.forEach {
RemoveDuplicatedInlinedLocalClassesLowering(context).removeUselessDeclarationsFromCapturedConstructors(it.parentAsClass, data)
}
val originalConstructor = capturedConstructors.keys.single {
it.parentAsClass.attributeOwnerId == constructorParent.attributeOwnerId && it.parentAsClass != constructorParent
}
val loweredConstructor = capturedConstructors[originalConstructor]!!
val newConstructorCall = IrConstructorCallImpl.fromSymbolOwner(
constructorCall.startOffset, constructorCall.endOffset,
loweredConstructor.parentAsClass.defaultType, loweredConstructor.symbol, constructorCall.origin
)
newConstructorCall.copyTypeAndValueArgumentsFrom(constructorCall)
if (lastStatement is IrConstructorCall) {
block.statements[block.statements.lastIndex] = newConstructorCall
} else if (lastStatement is IrBlock) {
lastStatement.statements[lastStatement.statements.lastIndex] = newConstructorCall
}
}
// Basically we want to remove all anonymous classes after inline. Exceptions are:
// 1. classes that must be regenerated (declaration.originalBeforeInline != null)
// 2. classes that are originally declared on call site or are default lambdas (data.classDeclaredOnCallSiteOrIsDefaultLambda == false)
override fun visitClass(declaration: IrClass, data: Data): IrStatement {
if (!data.insideInlineBlock || declaration.originalBeforeInline != null || !data.classDeclaredOnCallSiteOrIsDefaultLambda) {
return super.visitClass(declaration, data)
}
val constructor = declaration.primaryConstructor!!
capturedConstructors[constructor] = null // this action will do actual `remove`
capturedConstructors.keys.map { key -> // for each value in map
capturedConstructors[key]?.let {
if (it == constructor) {
capturedConstructors[key] = null
}
}
}
return if (data.modifyTree) {
IrCompositeImpl(declaration.startOffset, declaration.endOffset, context.irBuiltIns.unitType)
} else {
super.visitClass(declaration, data)
}
}
override fun visitFunctionReference(expression: IrFunctionReference, data: Data): IrElement {
if (!visited.add(expression.symbol.owner)) return expression
expression.symbol.owner.accept(this, data)
return super.visitFunctionReference(expression, data)
}
}