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JVM_IR: split AddContinuationLowering

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One half handles suspend lambdas, the other - named functions.
This commit is contained in:
pyos
2020-09-25 16:12:04 +02:00
committed by Alexander Udalov
parent 4f171a9eb5
commit 44e0bfe90b
2 changed files with 96 additions and 87 deletions
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compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmLower.kt
+1
View File
@@ -336,6 +336,7 @@ private val jvmFilePhases = listOf(
interfaceObjectCallsPhase,
tailCallOptimizationPhase,
suspendLambdaPhase,
addContinuationPhase,
innerClassesPhase,
compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/AddContinuationLowering.kt
+95 -87
View File
@@ -49,50 +49,71 @@ import org.jetbrains.kotlin.util.OperatorNameConventions
import org.jetbrains.kotlin.utils.DFS
import org.jetbrains.org.objectweb.asm.Type
internal val suspendLambdaPhase = makeIrFilePhase(
::SuspendLambdaLowering,
"SuspendLambda",
"Transform suspend lambda into continuation classes"
)
internal val addContinuationPhase = makeIrFilePhase(
::AddContinuationLowering,
"AddContinuation",
"Add continuation classes and parameters to suspend functions and transform suspend lambdas into continuations",
prerequisite = setOf(localDeclarationsPhase, tailCallOptimizationPhase)
"Add continuation classes and parameters to suspend functions",
prerequisite = setOf(suspendLambdaPhase, localDeclarationsPhase, tailCallOptimizationPhase)
)
private class AddContinuationLowering(private val context: JvmBackendContext) : FileLoweringPass {
private abstract class SuspendLoweringBase(protected val context: JvmBackendContext) : FileLoweringPass {
protected fun IrClass.createContinuationClassFor(
parent: IrDeclarationParent,
newOrigin: IrDeclarationOrigin,
newVisibility: DescriptorVisibility
): IrClass = context.irFactory.buildClass {
name = Name.special("<Continuation>")
origin = newOrigin
visibility = newVisibility
}.also { irClass ->
irClass.createImplicitParameterDeclarationWithWrappedDescriptor()
irClass.superTypes += defaultType
irClass.parent = parent
}
protected fun IrClass.addFunctionOverride(function: IrSimpleFunction): IrSimpleFunction =
addFunction(function.name.asString(), function.returnType).apply {
overriddenSymbols += function.symbol
valueParameters += function.valueParameters.map { it.copyTo(this) }
}
protected fun IrClass.addFunctionOverride(
function: IrSimpleFunction,
makeBody: IrBlockBodyBuilder.(IrFunction) -> Unit
): IrSimpleFunction =
addFunctionOverride(function).apply {
body = context.createIrBuilder(symbol).irBlockBody { makeBody(this@apply) }
}
protected fun IrSimpleFunction.generateErrorForInlineBody() {
val message = "This is a stub representing a copy of a suspend method without the state machine " +
"(used by the inliner). Since the difference is at the bytecode level, the body is " +
"still on the original function. Use suspendForInlineToOriginal() to retrieve it."
body = IrExpressionBodyImpl(startOffset, endOffset, IrErrorExpressionImpl(startOffset, endOffset, returnType, message))
}
protected fun IrFunction.addCompletionValueParameter(): IrValueParameter =
addValueParameter(SUSPEND_FUNCTION_COMPLETION_PARAMETER_NAME, continuationType())
protected fun IrFunction.continuationType(): IrType =
context.ir.symbols.continuationClass.typeWith(returnType).makeNullable()
}
private class SuspendLambdaLowering(context: JvmBackendContext) : SuspendLoweringBase(context) {
private class SuspendLambdaInfo(val reference: IrFunctionReference, val isRestricted: Boolean) {
val function = reference.symbol.owner
val arity = (reference.type as IrSimpleType).arguments.size - 1
val capturesCrossinline = function.valueParameters.any { reference.getValueArgument(it.index).isReadOfCrossinline() }
lateinit var constructor: IrConstructor
}
override fun lower(irFile: IrFile) {
transformSuspendLambdasIntoContinuations(irFile)
// This should be done after converting lambdas into classes to avoid breaking the invariant that
// each lambda is referenced at most once while creating `$$forInline` methods.
addContinuationObjectAndContinuationParameterToSuspendFunctions(irFile)
addContinuationParameterToSuspendCalls(irFile)
}
private fun addContinuationParameterToSuspendCalls(irFile: IrFile) {
irFile.transformChildrenVoid(object : IrElementTransformerVoid() {
val functionStack = mutableListOf<IrFunction>()
override fun visitFunction(declaration: IrFunction): IrStatement {
functionStack.push(declaration)
return super.visitFunction(declaration).also { functionStack.pop() }
}
override fun visitFunctionReference(expression: IrFunctionReference): IrExpression {
val transformed = super.visitFunctionReference(expression) as IrFunctionReference
// The only references not yet transformed into objects are inline lambdas; the continuation
// for those will be taken from the inline functions they are passed to, not the enclosing scope.
return transformed.retargetToSuspendView(context, null) {
IrFunctionReferenceImpl(startOffset, endOffset, type, it, typeArgumentsCount, reflectionTarget, origin)
}
}
override fun visitCall(expression: IrCall): IrExpression {
val transformed = super.visitCall(expression) as IrCall
return transformed.retargetToSuspendView(context, functionStack.peek() ?: return transformed) {
IrCallImpl(startOffset, endOffset, type, it, origin, superQualifierSymbol)
}
}
})
}
private fun transformSuspendLambdasIntoContinuations(irFile: IrFile) {
val inlineReferences = mutableSetOf<IrCallableReference<*>>()
val suspendLambdas = mutableMapOf<IrFunctionReference, SuspendLambdaInfo>()
irFile.acceptChildren(object : IrInlineReferenceLocator(context) {
@@ -117,7 +138,7 @@ private class AddContinuationLowering(private val context: JvmBackendContext) :
}, null)
for (lambda in suspendLambdas.values) {
(lambda.function.parent as IrDeclarationContainer).declarations.remove(lambda.function)
(lambda.function.parent as? IrDeclarationContainer)?.declarations?.remove(lambda.function)
}
irFile.transformChildrenVoid(object : IrElementTransformerVoidWithContext() {
override fun visitFunctionReference(expression: IrFunctionReference): IrExpression {
@@ -261,27 +282,6 @@ private class AddContinuationLowering(private val context: JvmBackendContext) :
}
}
private fun IrSimpleFunction.generateErrorForInlineBody() {
val message = "This is a stub representing a copy of a suspend method without the state machine " +
"(used by the inliner). Since the difference is at the bytecode level, the body is " +
"still on the original function. Use suspendForInlineToOriginal() to retrieve it."
body = IrExpressionBodyImpl(startOffset, endOffset, IrErrorExpressionImpl(startOffset, endOffset, returnType, message))
}
private fun IrClass.addFunctionOverride(function: IrSimpleFunction): IrSimpleFunction =
addFunction(function.name.asString(), function.returnType).apply {
overriddenSymbols += function.symbol
valueParameters += function.valueParameters.map { it.copyTo(this) }
}
private fun IrClass.addFunctionOverride(
function: IrSimpleFunction,
makeBody: IrBlockBodyBuilder.(IrFunction) -> Unit
): IrSimpleFunction =
addFunctionOverride(function).apply {
body = context.createIrBuilder(symbol).irBlockBody { makeBody(this@apply) }
}
// Invoke function in lambdas is responsible for
// 1) calling `create`
// 2) starting newly created coroutine by calling `invokeSuspend`.
@@ -350,25 +350,10 @@ private class AddContinuationLowering(private val context: JvmBackendContext) :
private fun IrBlockBodyBuilder.callInvokeSuspend(invokeSuspend: IrSimpleFunction, lambda: IrExpression): IrExpression {
// SingletonReferencesLowering has finished a while ago, so `irUnit()` won't work anymore.
val unitClass = context.irBuiltIns.unitClass
val unitField = this@AddContinuationLowering.context.cachedDeclarations.getFieldForObjectInstance(unitClass.owner)
val unitField = this@SuspendLambdaLowering.context.cachedDeclarations.getFieldForObjectInstance(unitClass.owner)
return irCallOp(invokeSuspend.symbol, invokeSuspend.returnType, lambda, irGetField(null, unitField))
}
private fun IrClass.createContinuationClassFor(
parent: IrDeclarationParent,
newOrigin: IrDeclarationOrigin,
newVisibility: DescriptorVisibility
): IrClass = context.irFactory.buildClass {
name = Name.special("<Continuation>")
origin = newOrigin
visibility = newVisibility
}.also { irClass ->
irClass.createImplicitParameterDeclarationWithWrappedDescriptor()
irClass.superTypes += defaultType
irClass.parent = parent
}
// Primary constructor accepts parameters equal to function reference arguments + continuation and sets the fields.
private fun IrClass.addPrimaryConstructorForLambda(
info: SuspendLambdaInfo,
@@ -402,12 +387,42 @@ private class AddContinuationLowering(private val context: JvmBackendContext) :
}
}
}
}
private fun IrFunction.addCompletionValueParameter(): IrValueParameter =
addValueParameter(SUSPEND_FUNCTION_COMPLETION_PARAMETER_NAME, continuationType())
private class AddContinuationLowering(context: JvmBackendContext) : SuspendLoweringBase(context) {
override fun lower(irFile: IrFile) {
// This should be done after converting lambdas into classes to avoid breaking the invariant that
// each lambda is referenced at most once while creating `$$forInline` methods.
addContinuationObjectAndContinuationParameterToSuspendFunctions(irFile)
addContinuationParameterToSuspendCalls(irFile)
}
private fun IrFunction.continuationType(): IrType =
context.ir.symbols.continuationClass.typeWith(returnType).makeNullable()
private fun addContinuationParameterToSuspendCalls(irFile: IrFile) {
irFile.transformChildrenVoid(object : IrElementTransformerVoid() {
val functionStack = mutableListOf<IrFunction>()
override fun visitFunction(declaration: IrFunction): IrStatement {
functionStack.push(declaration)
return super.visitFunction(declaration).also { functionStack.pop() }
}
override fun visitFunctionReference(expression: IrFunctionReference): IrExpression {
val transformed = super.visitFunctionReference(expression) as IrFunctionReference
// The only references not yet transformed into objects are inline lambdas; the continuation
// for those will be taken from the inline functions they are passed to, not the enclosing scope.
return transformed.retargetToSuspendView(context, null) {
IrFunctionReferenceImpl(startOffset, endOffset, type, it, typeArgumentsCount, reflectionTarget, origin)
}
}
override fun visitCall(expression: IrCall): IrExpression {
val transformed = super.visitCall(expression) as IrCall
return transformed.retargetToSuspendView(context, functionStack.peek() ?: return transformed) {
IrCallImpl(startOffset, endOffset, type, it, origin, superQualifierSymbol)
}
}
})
}
private fun generateContinuationClassForNamedFunction(
irFunction: IrFunction,
@@ -650,13 +665,6 @@ private class AddContinuationLowering(private val context: JvmBackendContext) :
}
}, null)
}
private class SuspendLambdaInfo(val reference: IrFunctionReference, val isRestricted: Boolean) {
val function = reference.symbol.owner
val arity = (reference.type as IrSimpleType).arguments.size - 1
val capturesCrossinline = function.valueParameters.any { reference.getValueArgument(it.index).isReadOfCrossinline() }
lateinit var constructor: IrConstructor
}
}
// Transform `suspend fun foo(params): RetType` into `fun foo(params, $completion: Continuation<RetType>): Any?`