ElementExt.kt
/*
* Copyright (C) 2020 The Android Open Source Project
*
* 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 androidx.room.compiler.processing.javac
import androidx.room.compiler.processing.XNullability
import com.google.auto.common.MoreElements
import com.google.auto.common.MoreTypes
import com.squareup.javapoet.ParameterizedTypeName
import com.squareup.javapoet.TypeName
import javax.lang.model.element.Element
import javax.lang.model.element.ExecutableElement
import javax.lang.model.element.Modifier
import javax.lang.model.element.TypeElement
import javax.lang.model.util.Types
import kotlin.coroutines.Continuation
private val NONNULL_ANNOTATIONS = arrayOf(
"androidx.annotation.NonNull",
"org.jetbrains.annotations.NotNull"
)
private val NULLABLE_ANNOTATIONS = arrayOf(
"androidx.annotation.Nullable",
"org.jetbrains.annotations.Nullable"
)
@Suppress("UnstableApiUsage")
private fun Element.hasAnyOf(annotations: Array<String>) =
annotationMirrors.any { annotationMirror ->
val annotationTypeElement = MoreElements.asType(annotationMirror.annotationType.asElement())
annotations.any { annotationTypeElement.qualifiedName.contentEquals(it) }
}
internal val Element.nullability: XNullability
get() = if (asType().kind.isPrimitive || hasAnyOf(NONNULL_ANNOTATIONS)) {
XNullability.NONNULL
} else if (hasAnyOf(NULLABLE_ANNOTATIONS)) {
XNullability.NULLABLE
} else {
XNullability.UNKNOWN
}
internal fun Element.requireEnclosingType(env: JavacProcessingEnv): JavacTypeElement {
return checkNotNull(enclosingType(env)) {
"Cannot find required enclosing type for $this"
}
}
@Suppress("UnstableApiUsage")
internal fun Element.enclosingType(env: JavacProcessingEnv): JavacTypeElement? {
return if (MoreElements.isType(enclosingElement)) {
env.wrapTypeElement(MoreElements.asType(enclosingElement))
} else {
null
}
}
/**
* Tests whether one suspend function, as a member of a given types, overrides another suspend
* function.
*
* This method assumes function one and two are suspend methods, i.e. they both return Object,
* have at least one parameter and the last parameter is of type Continuation. This method is
* similar to MoreElements.overrides() but doesn't check isSubsignature() due to Continuation's
* type arg being covariant, instead the equivalent is done by checking each parameter explicitly.
*/
internal fun suspendOverrides(
overrider: ExecutableElement,
overridden: ExecutableElement,
owner: TypeElement,
typeUtils: Types
): Boolean {
if (overrider.simpleName != overridden.simpleName) {
return false
}
if (overrider.enclosingElement == overridden.enclosingElement) {
return false
}
if (overridden.modifiers.contains(Modifier.STATIC)) {
return false
}
if (overridden.modifiers.contains(Modifier.PRIVATE)) {
return false
}
val overriddenType = overridden.enclosingElement as? TypeElement ?: return false
if (!typeUtils.isSubtype(
typeUtils.erasure(owner.asType()),
typeUtils.erasure(overriddenType.asType()))
) {
return false
}
val ownerType = MoreTypes.asDeclared(owner.asType())
val overriderExecutable = MoreTypes.asExecutable(typeUtils.asMemberOf(ownerType, overrider))
val overriddenExecutable = MoreTypes.asExecutable(typeUtils.asMemberOf(ownerType, overridden))
if (overriderExecutable.parameterTypes.size != overriddenExecutable.parameterTypes.size) {
return false
}
val continuationTypeName = TypeName.get(Continuation::class.java)
val overriderLastParamTypeName =
(TypeName.get(overriderExecutable.parameterTypes.last()) as? ParameterizedTypeName)
?.rawType
check(overriderLastParamTypeName == continuationTypeName) {
"Expected $overriderLastParamTypeName to be $continuationTypeName"
}
val overriddenLastParamTypeName =
(TypeName.get(overriddenExecutable.parameterTypes.last()) as? ParameterizedTypeName)
?.rawType
check(overriddenLastParamTypeName == continuationTypeName) {
"Expected $overriddenLastParamTypeName to be $continuationTypeName"
}
val overriderContinuationTypeArg =
MoreTypes.asDeclared(overriderExecutable.parameterTypes.last())
.typeArguments.single().let { it.extendsBound() ?: it }
val overriddenContinuationTypeArg =
MoreTypes.asDeclared(overriddenExecutable.parameterTypes.last())
.typeArguments.single().let { it.extendsBound() ?: it }
if (!typeUtils.isSameType(
typeUtils.erasure(overriderContinuationTypeArg),
typeUtils.erasure(overriddenContinuationTypeArg))
) {
return false
}
if (overriddenExecutable.parameterTypes.size >= 2) {
overriderExecutable.parameterTypes.zip(overriddenExecutable.parameterTypes)
.dropLast(1)
.forEach { (overriderParam, overriddenParam) ->
if (!typeUtils.isSameType(
typeUtils.erasure(overriderParam),
typeUtils.erasure(overriddenParam)
)
) {
return false
}
}
}
return true
}