org.jetbrains.kotlin.backend.common.bridges.impl.kt Maven / Gradle / Ivy
/*
* Copyright 2010-2015 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.backend.common.bridges
import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
import org.jetbrains.kotlin.descriptors.FunctionDescriptor
import org.jetbrains.kotlin.descriptors.Modality
import org.jetbrains.kotlin.resolve.DescriptorUtils
import org.jetbrains.kotlin.resolve.OverrideResolver
import org.jetbrains.kotlin.resolve.calls.callResolverUtil.isOrOverridesSynthesized
public fun generateBridgesForFunctionDescriptor(
descriptor: FunctionDescriptor,
signature: (FunctionDescriptor) -> Signature
): Set> {
return generateBridges(DescriptorBasedFunctionHandle(descriptor), { signature(it.descriptor) })
}
/**
* An implementation of FunctionHandle based on descriptors.
*
* This implementation workarounds a minor inconvenience in descriptor hierarchy regarding traits with implementations.
* Consider the following hierarchy:
*
* trait A { fun foo() = 42 }
* class B : A
*
* In terms of descriptors, we'll have a declaration in trait A with modality=OPEN and a fake override in class B with modality=OPEN.
* For the purposes of bridge generation though, it's much easier to "move" all implementations out of traits into their child classes,
* i.e. treat the function in A as a declaration with modality=ABSTRACT and a function in B as a _declaration_ with modality=OPEN.
*
* This provides us with the nice invariant that all implementations (concrete declarations) are always in classes. This means we _always_
* can generate a bridge near an implementation (of course, in case it has a super-declaration with a different signature). Ultimately this
* eases the process of determining what bridges are already generated in our supertypes and need to be inherited, not regenerated.
*/
private data class DescriptorBasedFunctionHandle(val descriptor: FunctionDescriptor) : FunctionHandle {
private val overridden = descriptor.getOverriddenDescriptors().map { DescriptorBasedFunctionHandle(it.getOriginal()) }
override val isDeclaration: Boolean =
descriptor.getKind().isReal() ||
findTraitImplementation(descriptor) != null
override val isAbstract: Boolean =
descriptor.getModality() == Modality.ABSTRACT ||
DescriptorUtils.isTrait(descriptor.getContainingDeclaration())
override fun getOverridden() = overridden
}
/**
* Given a fake override in a class, returns an overridden declaration with implementation in trait, such that a method delegating to that
* trait implementation should be generated into the class containing the fake override; or null if the given function is not a fake
* override of any trait implementation or such method was already generated into the superclass or is a method from Any.
*/
public fun findTraitImplementation(descriptor: CallableMemberDescriptor): CallableMemberDescriptor? {
if (descriptor.getKind().isReal()) return null
if (isOrOverridesSynthesized(descriptor)) return null
val implementation = findImplementationFromInterface(descriptor) ?: return null
val immediateConcreteSuper = firstSuperMethodFromKotlin(descriptor, implementation) ?: return null
if (!DescriptorUtils.isTrait(immediateConcreteSuper.getContainingDeclaration())) {
// If this implementation is already generated into the superclass, we need not generate it again, it'll be inherited
return null
}
return immediateConcreteSuper
}
/**
* Given a fake override, returns an overridden non-abstract function from an interface which is the actual implementation of this function
* that should be called when the given fake override is called.
*/
public fun findImplementationFromInterface(descriptor: CallableMemberDescriptor): CallableMemberDescriptor? {
val overridden = OverrideResolver.getOverriddenDeclarations(descriptor)
val filtered = OverrideResolver.filterOutOverridden(overridden)
val result = filtered.firstOrNull { it.getModality() != Modality.ABSTRACT } ?: return null
val container = result.getContainingDeclaration()
if (DescriptorUtils.isClass(container) || DescriptorUtils.isEnumClass(container)) return null
return result
}
/**
* Given a fake override and its implementation (non-abstract declaration) somewhere in supertypes,
* returns the first immediate super function of the given fake override which overrides that implementation.
* The returned function should be called from TImpl-bridges generated for the given fake override.
*/
public fun firstSuperMethodFromKotlin(
descriptor: CallableMemberDescriptor,
implementation: CallableMemberDescriptor
): CallableMemberDescriptor? {
return descriptor.getOverriddenDescriptors().firstOrNull { overridden ->
overridden.getModality() != Modality.ABSTRACT &&
(overridden == implementation || OverrideResolver.overrides(overridden, implementation))
}
}