| /* |
| * 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 |
| |
| import com.squareup.javapoet.TypeName |
| import kotlin.contracts.contract |
| import kotlin.reflect.KClass |
| |
| /** |
| * Represents a type reference |
| * |
| * @see javax.lang.model.type.TypeMirror |
| * @see [XArrayType] |
| * @see [XDeclaredType] |
| */ |
| interface XType { |
| /** |
| * The Javapoet [TypeName] representation of the type |
| */ |
| val typeName: TypeName |
| |
| /** |
| * Returns the rawType of this type. (e.g. `List<String>` to `List`. |
| */ |
| val rawType: XRawType |
| |
| /** |
| * Nullability declared in the code. |
| * For Kotlin types, it will be inferred from type declaration. |
| * For Java types, it will be inferred from annotations. |
| */ |
| val nullability: XNullability |
| |
| /** |
| * Casts the current type to [XTypeElement]. |
| * |
| * @see isType |
| */ |
| fun asTypeElement(): XTypeElement |
| |
| /** |
| * Returns `true` if this type can be assigned from [other] |
| */ |
| fun isAssignableFrom(other: XType): Boolean |
| |
| /** |
| * Returns `true` if this type can be assigned from [other] while ignoring the type variance. |
| */ |
| fun isAssignableFromWithoutVariance(other: XType): Boolean { |
| return isAssignableWithoutVariance(other, this) |
| } |
| |
| // TODO these is<Type> checks may need to be moved into the implementation. |
| // It is not yet clear how we will model some types in Kotlin (e.g. primitives) |
| /** |
| * Returns `true` if this is an error type. |
| */ |
| fun isError(): Boolean |
| |
| /** |
| * Returns the string representation of a possible default value for this type. |
| * (e.g. `0` for `int`, `null` for `String`) |
| */ |
| fun defaultValue(): String |
| |
| /** |
| * Returns boxed version of this type if it is a primitive or itself if it is not a primitive |
| * type. |
| */ |
| fun boxed(): XType |
| |
| /** |
| * Returns this type as an instance of [XArrayType] or fails if it is not an array. |
| */ |
| fun asArray(): XArrayType = this as XArrayType |
| |
| /** |
| * Returns `true` if this is a primitive or boxed it |
| */ |
| fun isInt(): Boolean |
| |
| /** |
| * Returns `true` if this is a primitive or boxed long |
| */ |
| fun isLong(): Boolean |
| |
| /** |
| * Returns `true` if this is a [List] |
| */ |
| fun isList(): Boolean = isType() && isTypeOf(List::class) |
| |
| /** |
| * Returns `true` if this is `void` |
| */ |
| fun isVoid() = typeName == TypeName.VOID |
| |
| /** |
| * Returns `true` if this is a [Void] |
| */ |
| fun isVoidObject(): Boolean = isType() && isTypeOf(Void::class) |
| |
| /** |
| * Returns `true` if this is the kotlin [Unit] type. |
| */ |
| fun isKotlinUnit(): Boolean = isType() && isTypeOf(Unit::class) |
| |
| /** |
| * Returns `true` if this represents a `byte`. |
| */ |
| fun isByte(): Boolean |
| |
| /** |
| * Returns `true` if this is the None type. |
| */ |
| fun isNone(): Boolean |
| |
| /** |
| * Returns true if this represented by a [XTypeElement]. |
| */ |
| fun isType(): Boolean |
| |
| /** |
| * Returns `true` if this is the same raw type as [other] |
| */ |
| fun isTypeOf(other: KClass<*>): Boolean |
| |
| /** |
| * Returns `true` if this represents the same type as [other]. |
| * TODO: decide on how we want to handle nullability here. |
| */ |
| fun isSameType(other: XType): Boolean |
| |
| /** |
| * Returns the extends bound if this is a wildcard or self. |
| */ |
| fun extendsBoundOrSelf(): XType = extendsBound() ?: this |
| |
| /** |
| * Returns `true` if this can be assigned from an instance of [other] without checking for |
| * variance. |
| */ |
| fun isAssignableWithoutVariance(other: XType): Boolean { |
| return isAssignableWithoutVariance(other, this) |
| } |
| |
| /** |
| * If this is a wildcard with an extends bound, returns that bounded typed. |
| */ |
| fun extendsBound(): XType? |
| } |
| |
| /** |
| * Returns true if this is an [XDeclaredType]. |
| */ |
| fun XType.isDeclared(): Boolean { |
| contract { |
| returns(true) implies (this@isDeclared is XDeclaredType) |
| } |
| return this is XDeclaredType |
| } |
| |
| /** |
| * Returns true if this is an [XArrayType]. |
| */ |
| fun XType.isArray(): Boolean { |
| contract { |
| returns(true) implies (this@isArray is XArrayType) |
| } |
| return this is XArrayType |
| } |
| |
| /** |
| * Returns true if this is a [List] or [Set]. |
| */ |
| fun XType.isCollection(): Boolean { |
| contract { |
| returns(true) implies (this@isCollection is XDeclaredType) |
| } |
| return isType() && (isTypeOf(List::class) || isTypeOf(Set::class)) |
| } |
| |
| /** |
| * Returns `this` as an [XDeclaredType]. |
| */ |
| fun XType.asDeclaredType() = this as XDeclaredType |
| |
| private fun isAssignableWithoutVariance(from: XType, to: XType): Boolean { |
| val assignable = to.isAssignableFrom(from) |
| if (assignable) { |
| return true |
| } |
| if (!from.isDeclared() || !to.isDeclared()) { |
| return false |
| } |
| val declaredFrom = from.asDeclaredType() |
| val declaredTo = to.asDeclaredType() |
| val fromTypeArgs = declaredFrom.typeArguments |
| val toTypeArgs = declaredTo.typeArguments |
| // no type arguments, we don't need extra checks |
| if (fromTypeArgs.isEmpty() || fromTypeArgs.size != toTypeArgs.size) { |
| return false |
| } |
| // check erasure version first, if it does not match, no reason to proceed |
| if (!to.rawType.isAssignableFrom(from)) { |
| return false |
| } |
| // convert from args to their upper bounds if it exists |
| val fromExtendsBounds = fromTypeArgs.map { |
| it.extendsBound() |
| } |
| // if there are no upper bound conversions, return. |
| if (fromExtendsBounds.all { it == null }) { |
| return false |
| } |
| // try to move the types of the from to their upper bounds. It does not matter for the "to" |
| // because Types.isAssignable handles it as it is valid java |
| return (fromTypeArgs.indices).all { index -> |
| isAssignableWithoutVariance( |
| from = fromExtendsBounds[index] ?: fromTypeArgs[index], |
| to = toTypeArgs[index] |
| ) |
| } |
| } |