TypeWriter.kt
/*
* Copyright 2022 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.writer
import androidx.room.RoomProcessor
import androidx.room.compiler.codegen.CodeLanguage
import androidx.room.compiler.codegen.XTypeSpec
import androidx.room.compiler.codegen.XTypeSpec.Builder.Companion.apply
import androidx.room.compiler.processing.XProcessingEnv
import androidx.room.compiler.processing.writeTo
import androidx.room.ext.S
import androidx.room.solver.CodeGenScope
import com.squareup.kotlinpoet.javapoet.JAnnotationSpec
import com.squareup.kotlinpoet.javapoet.KAnnotationSpec
import com.squareup.kotlinpoet.javapoet.toKClassName
import kotlin.reflect.KClass
/**
* Base class for all writers that can produce a class.
*/
abstract class TypeWriter(val codeLanguage: CodeLanguage) {
// TODO(danysantiago): Migrate to XPoet
private val sharedFieldSpecs = mutableMapOf<String, com.squareup.javapoet.FieldSpec>()
private val sharedMethodSpecs = mutableMapOf<String, com.squareup.javapoet.MethodSpec>()
private val sharedFieldNames = mutableSetOf<String>()
private val sharedMethodNames = mutableSetOf<String>()
private val metadata = mutableMapOf<KClass<*>, Any>()
abstract fun createTypeSpecBuilder(): XTypeSpec.Builder
/**
* Read additional metadata that can be put by sub code generators.
*
* @see set for more details.
*/
operator fun <T> get(key: KClass<*>): T? {
@Suppress("UNCHECKED_CAST")
return metadata[key] as? T
}
/**
* Add additional metadata to the TypeWriter that can be read back later.
* This is useful for additional functionality where a sub code generator needs to bubble up
* information to the main TypeWriter without copying it in every intermediate step.
*
* @see get
*/
operator fun set(key: KClass<*>, value: Any) {
metadata[key] = value
}
fun write(processingEnv: XProcessingEnv) {
val builder = createTypeSpecBuilder()
builder.apply(
javaTypeBuilder = {
sharedFieldSpecs.values.forEach { addField(it) }
sharedMethodSpecs.values.forEach { addMethod(it) }
},
kotlinTypeBuilder = { }
)
addGeneratedAnnotationIfAvailable(builder, processingEnv)
addSuppressWarnings(builder)
builder.build().writeTo(processingEnv.filer)
}
private fun addSuppressWarnings(builder: XTypeSpec.Builder) {
val suppressionKeys = arrayOf("unchecked", "deprecation")
builder.apply(
javaTypeBuilder = {
addAnnotation(
com.squareup.javapoet.AnnotationSpec.builder(SuppressWarnings::class.java)
.addMember("value", "{$S, $S}", *suppressionKeys)
.build()
)
},
kotlinTypeBuilder = {
addAnnotation(
com.squareup.kotlinpoet.AnnotationSpec.builder(Suppress::class)
.addMember("names = [%S, %S]", *suppressionKeys)
.build()
)
}
)
}
private fun addGeneratedAnnotationIfAvailable(
adapterTypeSpecBuilder: XTypeSpec.Builder,
processingEnv: XProcessingEnv
) {
processingEnv.findGeneratedAnnotation()?.let {
val memberValue = RoomProcessor::class.java.canonicalName
adapterTypeSpecBuilder.apply(
javaTypeBuilder = {
addAnnotation(
JAnnotationSpec.builder(it.className)
.addMember("value", "$S", memberValue)
.build()
)
},
kotlinTypeBuilder = {
addAnnotation(
KAnnotationSpec.builder(it.className.toKClassName())
.addMember("value = [%S]", memberValue)
.build()
)
}
)
}
}
private fun makeUnique(set: MutableSet<String>, value: String): String {
if (!value.startsWith(CodeGenScope.CLASS_PROPERTY_PREFIX)) {
return makeUnique(set, "${CodeGenScope.CLASS_PROPERTY_PREFIX}$value")
}
if (set.add(value)) {
return value
}
var index = 1
while (true) {
if (set.add("${value}_$index")) {
return "${value}_$index"
}
index++
}
}
fun getOrCreateField(sharedField: SharedFieldSpec): com.squareup.javapoet.FieldSpec {
return sharedFieldSpecs.getOrPut(sharedField.getUniqueKey()) {
sharedField.build(this, makeUnique(sharedFieldNames, sharedField.baseName))
}
}
fun getOrCreateMethod(sharedMethod: SharedMethodSpec): com.squareup.javapoet.MethodSpec {
return sharedMethodSpecs.getOrPut(sharedMethod.getUniqueKey()) {
sharedMethod.build(this, makeUnique(sharedMethodNames, sharedMethod.baseName))
}
}
abstract class SharedFieldSpec(val baseName: String, val type: com.squareup.javapoet.TypeName) {
abstract fun getUniqueKey(): String
abstract fun prepare(writer: TypeWriter, builder: com.squareup.javapoet.FieldSpec.Builder)
fun build(classWriter: TypeWriter, name: String): com.squareup.javapoet.FieldSpec {
val builder = com.squareup.javapoet.FieldSpec.builder(type, name)
prepare(classWriter, builder)
return builder.build()
}
}
abstract class SharedMethodSpec(val baseName: String) {
abstract fun getUniqueKey(): String
abstract fun prepare(
methodName: String,
writer: TypeWriter,
builder: com.squareup.javapoet.MethodSpec.Builder
)
fun build(writer: TypeWriter, name: String): com.squareup.javapoet.MethodSpec {
val builder = com.squareup.javapoet.MethodSpec.methodBuilder(name)
prepare(name, writer, builder)
return builder.build()
}
}
}