org.jetbrains.kotlin.backend.jvm.lower.JvmStaticAnnotationLowering.kt Maven / Gradle / Ivy
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/*
* Copyright 2010-2020 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.phaser.makeIrFilePhase
import org.jetbrains.kotlin.backend.common.phaser.makeIrModulePhase
import org.jetbrains.kotlin.backend.jvm.CachedFieldsForObjectInstances
import org.jetbrains.kotlin.backend.jvm.JvmBackendContext
import org.jetbrains.kotlin.backend.jvm.JvmLoweredDeclarationOrigin
import org.jetbrains.kotlin.backend.jvm.ir.isEffectivelyInlineOnly
import org.jetbrains.kotlin.backend.jvm.ir.isInlineFunctionCall
import org.jetbrains.kotlin.backend.jvm.ir.replaceThisByStaticReference
import org.jetbrains.kotlin.descriptors.DescriptorVisibilities
import org.jetbrains.kotlin.ir.IrBuiltIns
import org.jetbrains.kotlin.ir.IrStatement
import org.jetbrains.kotlin.ir.declarations.*
import org.jetbrains.kotlin.ir.expressions.*
import org.jetbrains.kotlin.ir.expressions.impl.IrBlockImpl
import org.jetbrains.kotlin.ir.expressions.impl.IrFunctionReferenceImpl
import org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl
import org.jetbrains.kotlin.ir.util.*
import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
import org.jetbrains.kotlin.resolve.annotations.JVM_STATIC_ANNOTATION_FQ_NAME
internal val jvmStaticInObjectPhase = makeIrModulePhase(
::JvmStaticInObjectLowering,
name = "JvmStaticInObject",
description = "Make JvmStatic functions in non-companion objects static and replace all call sites in the module"
)
internal val jvmStaticInCompanionPhase = makeIrFilePhase(
::JvmStaticInCompanionLowering,
name = "JvmStaticInCompanion",
description = "Synthesize static proxy functions for JvmStatic functions in companion objects"
)
private class JvmStaticInObjectLowering(val context: JvmBackendContext) : FileLoweringPass {
override fun lower(irFile: IrFile) =
irFile.transformChildrenVoid(
SingletonObjectJvmStaticTransformer(context.irBuiltIns, context.cachedDeclarations.fieldsForObjectInstances)
)
}
private class JvmStaticInCompanionLowering(val context: JvmBackendContext) : FileLoweringPass {
override fun lower(irFile: IrFile) =
irFile.transformChildrenVoid(CompanionObjectJvmStaticTransformer(context))
}
private fun IrDeclaration.isJvmStaticDeclaration(): Boolean =
hasAnnotation(JVM_STATIC_ANNOTATION_FQ_NAME) ||
(this as? IrSimpleFunction)?.correspondingPropertySymbol?.owner?.hasAnnotation(JVM_STATIC_ANNOTATION_FQ_NAME) == true ||
(this as? IrProperty)?.getter?.hasAnnotation(JVM_STATIC_ANNOTATION_FQ_NAME) == true
private fun IrDeclaration.isJvmStaticInCompanion(): Boolean =
isJvmStaticDeclaration() && (parent as? IrClass)?.isCompanion == true
internal fun IrDeclaration.isJvmStaticInObject(): Boolean =
isJvmStaticDeclaration() && (parent as? IrClass)?.isNonCompanionObject == true
// `coerceToUnit()` is private in InsertImplicitCasts, have to reproduce it here
private fun IrExpression.coerceToUnit(irBuiltIns: IrBuiltIns) =
IrTypeOperatorCallImpl(startOffset, endOffset, irBuiltIns.unitType, IrTypeOperator.IMPLICIT_COERCION_TO_UNIT, irBuiltIns.unitType, this)
private fun IrMemberAccessExpression<*>.makeStatic(irBuiltIns: IrBuiltIns, replaceCallee: IrSimpleFunction?): IrExpression {
val receiver = dispatchReceiver ?: return this
dispatchReceiver = null
if (replaceCallee != null) {
(this as IrCall).symbol = replaceCallee.symbol
}
if (receiver.isTrivial()) {
// Receiver has no side effects (aside from maybe class initialization) so discard it.
return this
}
return IrBlockImpl(startOffset, endOffset, type).apply {
statements += receiver.coerceToUnit(irBuiltIns) // evaluate for side effects
statements += this@makeStatic
}
}
class SingletonObjectJvmStaticTransformer(
private val irBuiltIns: IrBuiltIns,
private val cachedFields: CachedFieldsForObjectInstances
) : IrElementTransformerVoid() {
override fun visitClass(declaration: IrClass): IrStatement {
if (declaration.isNonCompanionObject) {
for (function in declaration.simpleFunctions()) {
if (function.isJvmStaticDeclaration()) {
// dispatch receiver parameter is already null for synthetic property annotation methods
function.dispatchReceiverParameter?.let { oldDispatchReceiverParameter ->
function.dispatchReceiverParameter = null
function.replaceThisByStaticReference(cachedFields, declaration, oldDispatchReceiverParameter)
}
}
}
}
return super.visitClass(declaration)
}
// This lowering runs before functions references are handled, and should transform them too.
override fun visitMemberAccess(expression: IrMemberAccessExpression<*>): IrExpression {
expression.transformChildrenVoid(this)
val callee = expression.symbol.owner
if (callee is IrDeclaration && callee.isJvmStaticInObject()) {
return expression.makeStatic(irBuiltIns, replaceCallee = null)
}
return expression
}
}
private class CompanionObjectJvmStaticTransformer(val context: JvmBackendContext) : IrElementTransformerVoid() {
// TODO: would be nice to add a mode that *only* leaves static versions for all annotated methods, with nothing
// in companions - this would reduce the number of classes if the companion only has `@JvmStatic` declarations.
private fun IrSimpleFunction.needsStaticProxy(): Boolean = when {
// Case 1: `external` static methods are moved to the outer class. JNI code does not care about visibility.
isExternal -> true
// Case 2: `JvmStatic` is useless on inline-only methods because they're not visible to any Java code anyway.
origin == JvmLoweredDeclarationOrigin.SYNTHETIC_METHOD_FOR_PROPERTY_OR_TYPEALIAS_ANNOTATIONS -> false
isEffectivelyInlineOnly() -> false
// Case 3: protected non-inline needs a static proxy in the parent to be callable from subclasses
// of said parent in different packages even in pure Kotlin due to JVM visibility rules.
visibility == DescriptorVisibilities.PROTECTED && !isInline -> true
// Case 4: public or protected inline needs a static proxy if not synthetic to be callable
// on the parent class from Java code (the original point of this annotation).
else -> !origin.isSynthetic
}
override fun visitClass(declaration: IrClass): IrStatement =
super.visitClass(declaration).also {
declaration.companionObject()?.declarations?.transformInPlace {
if (it is IrSimpleFunction && it.isJvmStaticDeclaration() && it.needsStaticProxy()) {
val (static, companionFun) = context.cachedDeclarations.getStaticAndCompanionDeclaration(it)
declaration.declarations.add(static)
companionFun
} else it
}
}
// By this point all callable references have already been lowered (except ones for signature-generating
// intrinsics, which do not care about accessibility rules), so only calls remain.
override fun visitCall(expression: IrCall): IrExpression {
expression.transformChildrenVoid(this)
val callee = expression.symbol.owner
return when {
shouldReplaceWithStaticCall(callee) -> {
val (staticProxy, _) = context.cachedDeclarations.getStaticAndCompanionDeclaration(callee)
expression.makeStatic(context.irBuiltIns, staticProxy)
}
callee.symbol == context.ir.symbols.indyLambdaMetafactoryIntrinsic -> {
val implFunRef = expression.getValueArgument(1) as? IrFunctionReference
?: throw AssertionError("'implMethodReference' is expected to be 'IrFunctionReference': ${expression.dump()}")
val implFun = implFunRef.symbol.owner
if (implFunRef.dispatchReceiver != null && implFun is IrSimpleFunction && shouldReplaceWithStaticCall(implFun)) {
val (staticProxy, _) = context.cachedDeclarations.getStaticAndCompanionDeclaration(implFun)
expression.putValueArgument(
1,
IrFunctionReferenceImpl(
implFunRef.startOffset, implFunRef.endOffset, implFunRef.type,
staticProxy.symbol,
staticProxy.typeParameters.size,
staticProxy.valueParameters.size,
implFunRef.reflectionTarget, implFunRef.origin
)
)
}
expression
}
else ->
expression
}
}
private fun shouldReplaceWithStaticCall(callee: IrSimpleFunction) =
callee.isJvmStaticInCompanion() &&
callee.visibility == DescriptorVisibilities.PROTECTED &&
!callee.isInlineFunctionCall(context)
}