Migrate to KotlinPoet-metadata (#903)

* Add kotlinpoet version to properties * Swap in kotlinpoet-metadata for kotlin-metadata in dependencies * Don't use KotlinMetadataUtils and KotlinAbstractProcessor anymore * Upcast to TypeElement * Temporarily add direct kotlinx-metadata dependency Something is wrong with packaging in my local kotlinpoet, will remove before * Remove tags API from TargetParameter No longer needed * Add PropertySpec directly to TargetProperty, remove holder funs Simplifies some things! * Move generated annotation gen into type callback Removes JsonClassCodegenProcessor completely from codegen API * Remove unstable autocommon dependency Won't be using this anymore after this change * Manually put quotes jsonName in AdapterGenerator Otherwise we could incur double escaping from kotlinpoet since we directly reuse possible-escaped parsed `@Json` name values * Opt in to use `@UseExperimental` annotation for preview * Rework and simplify metadata to just use kotlinpoet-metadata This is hard to do in broken down 1:1 steps, but the net result is a much smaller implementation footprint, better error messages, and a simpler API interaction with the code gen API. There is some raw parsing of kotlinpoet types required (mostly around annotations), but otherwise it's pretty smooth sailing and a good test of the upcoming kotlinpoet-metadata support * Declare KotlinPoetMetadataPreview directly * Try to point to snapshots for CI build * Update to classinspector API * Remove TypeResolver API No longer needed * Kotlinpoet 1.4.0 final * Fix missing import from rebase * Remove old kotlin-metadata version
2025-10-20 00:19:21 +08:00 · 2019-09-25 22:22:44 -04:00
parent 5f98e93698
commit 54d07b6cbf
11 changed files with 211 additions and 683 deletions
--- a/kotlin/codegen/pom.xml
+++ b/kotlin/codegen/pom.xml
@@ -27,6 +27,26 @@
      <artifactId>kotlinpoet</artifactId>
      <version>${kotlinpoet.version}</version>
    </dependency>
+    <dependency>
+      <groupId>org.jetbrains.kotlinx</groupId>
+      <artifactId>kotlinx-metadata-jvm</artifactId>
+      <version>0.1.0</version>
+    </dependency>
+    <dependency>
+      <groupId>com.squareup</groupId>
+      <artifactId>kotlinpoet-metadata</artifactId>
+      <version>${kotlinpoet.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.squareup</groupId>
+      <artifactId>kotlinpoet-metadata-specs</artifactId>
+      <version>${kotlinpoet.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>com.squareup</groupId>
+      <artifactId>kotlinpoet-classinspector-elements</artifactId>
+      <version>${kotlinpoet.version}</version>
+    </dependency>
    <dependency>
      <groupId>net.ltgt.gradle.incap</groupId>
      <artifactId>incap</artifactId>
@@ -34,11 +54,6 @@
      <scope>provided</scope>
      <optional>true</optional>
    </dependency>
-    <dependency>
-      <groupId>com.google.auto</groupId>
-      <artifactId>auto-common</artifactId>
-      <version>${auto-common.version}</version>
-    </dependency>
    <dependency>
      <groupId>com.google.auto.service</groupId>
      <artifactId>auto-service-annotations</artifactId>
@@ -67,10 +82,6 @@
      The Kotlin compiler usage must be near the end of the list because its .jar file includes an
      obsolete version of Guava!
    -->
-    <dependency>
-      <groupId>me.eugeniomarletti.kotlin.metadata</groupId>
-      <artifactId>kotlin-metadata</artifactId>
-    </dependency>
    <dependency>
      <groupId>com.github.tschuchortdev</groupId>
      <artifactId>kotlin-compile-testing</artifactId>
@@ -135,6 +146,12 @@
            </goals>
          </execution>
        </executions>
+        <configuration>
+          <args>
+            <!-- So we can declare ourselves as users of KotlinPoetMetadataPreview -->
+            <arg>-Xuse-experimental=com.squareup.kotlinpoet.metadata.KotlinPoetMetadataPreview</arg>
+          </args>
+        </configuration>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/AppliedType.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/AppliedType.kt
@@ -15,10 +15,6 @@
 */
 package com.squareup.moshi.kotlin.codegen

-import com.squareup.kotlinpoet.TypeName
-import com.squareup.kotlinpoet.TypeVariableName
-import com.squareup.kotlinpoet.asTypeName
-import com.squareup.moshi.kotlin.codegen.api.TypeResolver
 import javax.lang.model.element.TypeElement
 import javax.lang.model.type.DeclaredType
 import javax.lang.model.util.Types
@@ -29,7 +25,6 @@ import javax.lang.model.util.Types
 */
 internal class AppliedType private constructor(
  val element: TypeElement,
-  val resolver: TypeResolver,
  private val mirror: DeclaredType
 ) {
  /** Returns all supertypes of this, recursively. Includes both interface and class supertypes. */
@@ -41,32 +36,17 @@ internal class AppliedType private constructor(
    for (supertype in types.directSupertypes(mirror)) {
      val supertypeDeclaredType = supertype as DeclaredType
      val supertypeElement = supertypeDeclaredType.asElement() as TypeElement
-      val appliedSupertype = AppliedType(supertypeElement,
-          resolver(supertypeElement, supertypeDeclaredType), supertypeDeclaredType)
+      val appliedSupertype = AppliedType(supertypeElement, supertypeDeclaredType)
      appliedSupertype.supertypes(types, result)
    }
    return result
  }

-  /** Returns a resolver that uses `element` and `mirror` to resolve type parameters. */
-  private fun resolver(element: TypeElement, mirror: DeclaredType): TypeResolver {
-    return object : TypeResolver() {
-      override fun resolveTypeVariable(typeVariable: TypeVariableName): TypeName {
-        val index = element.typeParameters.indexOfFirst {
-          it.simpleName.toString() == typeVariable.name
-        }
-        check(index != -1) { "Unexpected type variable $typeVariable in $mirror" }
-        val argument = mirror.typeArguments[index]
-        return argument.asTypeName()
-      }
-    }
-  }
-
  override fun toString() = mirror.toString()

  companion object {
    fun get(typeElement: TypeElement): AppliedType {
-      return AppliedType(typeElement, TypeResolver(), typeElement.asType() as DeclaredType)
+      return AppliedType(typeElement, typeElement.asType() as DeclaredType)
    }
  }
 }
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/JsonClassCodegenProcessor.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/JsonClassCodegenProcessor.kt
@@ -16,22 +16,25 @@
 package com.squareup.moshi.kotlin.codegen

 import com.google.auto.service.AutoService
+import com.squareup.kotlinpoet.AnnotationSpec
 import com.squareup.kotlinpoet.asClassName
+import com.squareup.kotlinpoet.metadata.KotlinPoetMetadataPreview
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.kotlin.codegen.api.AdapterGenerator
 import com.squareup.moshi.kotlin.codegen.api.PropertyGenerator
-import me.eugeniomarletti.kotlin.metadata.KotlinMetadataUtils
-import me.eugeniomarletti.kotlin.processing.KotlinAbstractProcessor
 import net.ltgt.gradle.incap.IncrementalAnnotationProcessor
 import net.ltgt.gradle.incap.IncrementalAnnotationProcessorType.ISOLATING
+import javax.annotation.processing.AbstractProcessor
+import javax.annotation.processing.Filer
+import javax.annotation.processing.Messager
 import javax.annotation.processing.ProcessingEnvironment
 import javax.annotation.processing.Processor
 import javax.annotation.processing.RoundEnvironment
 import javax.lang.model.SourceVersion
-import javax.lang.model.element.Element
 import javax.lang.model.element.TypeElement
-import javax.lang.model.element.VariableElement
-import javax.tools.Diagnostic.Kind.ERROR
+import javax.lang.model.util.Elements
+import javax.lang.model.util.Types
+import javax.tools.Diagnostic

 /**
 * An annotation processor that reads Kotlin data classes and generates Moshi JsonAdapters for them.
@@ -40,13 +43,11 @@ import javax.tools.Diagnostic.Kind.ERROR
 *
 * The generated class will match the visibility of the given data class (i.e. if it's internal, the
 * adapter will also be internal).
- *
- * If you define a companion object, a jsonAdapter() extension function will be generated onto it.
- * If you don't want this though, you can use the runtime [JsonClass] factory implementation.
 */
+@KotlinPoetMetadataPreview
@AutoService(Processor::class)
@IncrementalAnnotationProcessor(ISOLATING)
-class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils {
+class JsonClassCodegenProcessor : AbstractProcessor() {

  companion object {
    /**
@@ -65,6 +66,10 @@ class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils
    )
  }

+  private lateinit var types: Types
+  private lateinit var elements: Elements
+  private lateinit var filer: Filer
+  private lateinit var messager: Messager
  private val annotation = JsonClass::class.java
  private var generatedType: TypeElement? = null

@@ -83,16 +88,37 @@ class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils
      }
      processingEnv.elementUtils.getTypeElement(it)
    }
+    this.types = processingEnv.typeUtils
+    this.elements = processingEnv.elementUtils
+    this.filer = processingEnv.filer
+    this.messager = processingEnv.messager
  }

  override fun process(annotations: Set<TypeElement>, roundEnv: RoundEnvironment): Boolean {
    for (type in roundEnv.getElementsAnnotatedWith(annotation)) {
+      if (type !is TypeElement) {
+        messager.printMessage(
+            Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $type: must be a Kotlin class",
+            type)
+        continue
+      }
      val jsonClass = type.getAnnotation(annotation)
      if (jsonClass.generateAdapter && jsonClass.generator.isEmpty()) {
        val generator = adapterGenerator(type) ?: continue
        generator
-            .generateFile(generatedType?.asClassName()) {
+            .generateFile {
              it.toBuilder()
+                  .apply {
+                    generatedType?.asClassName()?.let { generatedClassName ->
+                      addAnnotation(
+                          AnnotationSpec.builder(generatedClassName)
+                              .addMember("value = [%S]",
+                                  JsonClassCodegenProcessor::class.java.canonicalName)
+                              .addMember("comments = %S", "https://github.com/square/moshi")
+                              .build()
+                      )
+                    }
+                  }
                  .addOriginatingElement(type)
                  .build()
            }
@@ -103,12 +129,12 @@ class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils
    return false
  }

-  private fun adapterGenerator(element: Element): AdapterGenerator? {
-    val type = targetType(messager, elementUtils, typeUtils, element) ?: return null
+  private fun adapterGenerator(element: TypeElement): AdapterGenerator? {
+    val type = targetType(messager, elements, types, element) ?: return null

    val properties = mutableMapOf<String, PropertyGenerator>()
    for (property in type.properties.values) {
-      val generator = property.generator(messager)
+      val generator = property.generator(messager, element, elements)
      if (generator != null) {
        properties[property.name] = generator
      }
@@ -117,7 +143,9 @@ class JsonClassCodegenProcessor : KotlinAbstractProcessor(), KotlinMetadataUtils
    for ((name, parameter) in type.constructor.parameters) {
      if (type.properties[parameter.name] == null && !parameter.hasDefault) {
        messager.printMessage(
-            ERROR, "No property for required constructor parameter $name", parameter.tag<VariableElement>())
+            Diagnostic.Kind.ERROR,
+            "No property for required constructor parameter $name",
+            element)
        return null
      }
    }
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/AdapterGenerator.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/AdapterGenerator.kt
@@ -17,7 +17,6 @@ package com.squareup.moshi.kotlin.codegen.api

 import com.squareup.kotlinpoet.ARRAY
 import com.squareup.kotlinpoet.AnnotationSpec
-import com.squareup.kotlinpoet.ClassName
 import com.squareup.kotlinpoet.CodeBlock
 import com.squareup.kotlinpoet.FileSpec
 import com.squareup.kotlinpoet.FunSpec
@@ -36,7 +35,6 @@ import com.squareup.moshi.JsonReader
 import com.squareup.moshi.JsonWriter
 import com.squareup.moshi.Moshi
 import com.squareup.moshi.internal.Util
-import com.squareup.moshi.kotlin.codegen.JsonClassCodegenProcessor
 import java.lang.reflect.Constructor
 import java.lang.reflect.Type

@@ -83,7 +81,8 @@ internal class AdapterGenerator(
      nameAllocator.newName("options"), JsonReader.Options::class.asTypeName(),
      KModifier.PRIVATE)
      .initializer("%T.of(${nonTransientProperties.joinToString(", ") {
-        CodeBlock.of("%S", it.jsonName).toString()
+        // We manually put in quotes because we know the jsonName is already escaped
+        CodeBlock.of("\"%L\"", it.jsonName).toString()
      }})", JsonReader.Options::class.asTypeName())
      .build()

@@ -96,27 +95,20 @@ internal class AdapterGenerator(
      .initializer("null")
      .build()

-  fun generateFile(generatedOption: ClassName?, typeHook: (TypeSpec) -> TypeSpec = { it }): FileSpec {
+  fun generateFile(typeHook: (TypeSpec) -> TypeSpec = { it }): FileSpec {
    for (property in nonTransientProperties) {
      property.allocateNames(nameAllocator)
    }

    val result = FileSpec.builder(className.packageName, adapterName)
    result.addComment("Code generated by moshi-kotlin-codegen. Do not edit.")
-    result.addType(generateType(generatedOption).let(typeHook))
+    result.addType(generateType().let(typeHook))
    return result.build()
  }

-  private fun generateType(generatedOption: ClassName?): TypeSpec {
+  private fun generateType(): TypeSpec {
    val result = TypeSpec.classBuilder(adapterName)

-    generatedOption?.let {
-      result.addAnnotation(AnnotationSpec.builder(it)
-          .addMember("value = [%S]", JsonClassCodegenProcessor::class.java.canonicalName)
-          .addMember("comments = %S", "https://github.com/square/moshi")
-          .build())
-    }
-
    result.superclass(jsonAdapterTypeName)

    if (typeVariables.isNotEmpty()) {
@@ -366,7 +358,8 @@ internal class AdapterGenerator(

    result.addStatement("%N.beginObject()", writerParam)
    nonTransientProperties.forEach { property ->
-      result.addStatement("%N.name(%S)", writerParam, property.jsonName)
+      // We manually put in quotes because we know the jsonName is already escaped
+      result.addStatement("%N.name(\"%L\")", writerParam, property.jsonName)
      result.addStatement("%N.toJson(%N, %N.%N)",
          nameAllocator[property.delegateKey], writerParam, valueParam, property.name)
    }
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetParameter.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetParameter.kt
@@ -16,7 +16,6 @@
 package com.squareup.moshi.kotlin.codegen.api

 import com.squareup.kotlinpoet.AnnotationSpec
-import kotlin.reflect.KClass

 /** A parameter in user code that should be populated by generated code. */
 internal data class TargetParameter(
@@ -24,15 +23,5 @@ internal data class TargetParameter(
  val index: Int,
  val hasDefault: Boolean,
  val jsonName: String = name,
-  val qualifiers: Set<AnnotationSpec>? = null,
-  private val tags: Map<KClass<*>, Any>
-) {
-  /** Returns the tag attached with [type] as a key, or null if no tag is attached with that key. */
-  fun <T : Any> tag(type: KClass<out T>): T? {
-    @Suppress("UNCHECKED_CAST")
-    return tags[type] as T?
-  }
-
-  /** Returns the tag attached with [T] as a key, or null if no tag is attached with that key. */
-  inline fun <reified T : Any> tag(): T? = tag(T::class)
-}
+  val qualifiers: Set<AnnotationSpec>? = null
+)
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetProperty.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetProperty.kt
@@ -15,23 +15,19 @@
 */
 package com.squareup.moshi.kotlin.codegen.api

-import com.squareup.kotlinpoet.FunSpec
 import com.squareup.kotlinpoet.KModifier
 import com.squareup.kotlinpoet.PropertySpec
 import com.squareup.kotlinpoet.TypeName

 /** A property in user code that maps to JSON. */
 internal data class TargetProperty(
-  val name: String,
-  val type: TypeName,
+  val propertySpec: PropertySpec,
  val parameter: TargetParameter?,
-  val annotationHolder: FunSpec?,
-  val field: PropertySpec?,
-  val setter: FunSpec?,
-  val getter: FunSpec?,
  val visibility: KModifier,
  val jsonName: String
 ) {
+  val name: String get() = propertySpec.name
+  val type: TypeName get() = propertySpec.type
  val parameterIndex get() = parameter?.index ?: -1
  val hasDefault get() = parameter?.hasDefault ?: true

--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TypeResolver.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TypeResolver.kt
@@ -1,63 +0,0 @@
-/*
- * Copyright (C) 2018 Square, Inc.
- *
- * 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 com.squareup.moshi.kotlin.codegen.api
-
-import com.squareup.kotlinpoet.ClassName
-import com.squareup.kotlinpoet.ParameterizedTypeName
-import com.squareup.kotlinpoet.ParameterizedTypeName.Companion.parameterizedBy
-import com.squareup.kotlinpoet.TypeName
-import com.squareup.kotlinpoet.TypeVariableName
-import com.squareup.kotlinpoet.WildcardTypeName
-
-/**
- * Resolves type parameters against a type declaration. Use this to fill in type variables with
- * their actual type parameters.
- */
-open class TypeResolver {
-  open fun resolveTypeVariable(typeVariable: TypeVariableName): TypeName = typeVariable
-
-  fun resolve(typeName: TypeName): TypeName {
-    return when (typeName) {
-      is ClassName -> typeName
-
-      is ParameterizedTypeName -> {
-            typeName.rawType.parameterizedBy(*(typeName.typeArguments.map { resolve(it) }.toTypedArray()))
-            .copy(nullable = typeName.isNullable)
-      }
-
-      is WildcardTypeName -> {
-        when {
-          typeName.inTypes.size == 1 -> {
-            WildcardTypeName.consumerOf(resolve(typeName.inTypes[0]))
-                .copy(nullable = typeName.isNullable)
-          }
-          typeName.outTypes.size == 1 -> {
-            WildcardTypeName.producerOf(resolve(typeName.outTypes[0]))
-                .copy(nullable = typeName.isNullable)
-          }
-          else -> {
-            throw IllegalArgumentException(
-                "Unrepresentable wildcard type. Cannot have more than one bound: $typeName")
-          }
-        }
-      }
-
-      is TypeVariableName -> resolveTypeVariable(typeName)
-
-      else -> throw IllegalArgumentException("Unrepresentable type: $typeName")
-    }
-  }
-}
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/metadata.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/metadata.kt
@@ -15,26 +15,23 @@
 */
 package com.squareup.moshi.kotlin.codegen

-import com.google.auto.common.AnnotationMirrors
-import com.google.auto.common.MoreTypes
 import com.squareup.kotlinpoet.AnnotationSpec
 import com.squareup.kotlinpoet.ClassName
-import com.squareup.kotlinpoet.CodeBlock
-import com.squareup.kotlinpoet.FunSpec
 import com.squareup.kotlinpoet.KModifier
-import com.squareup.kotlinpoet.KModifier.PUBLIC
-import com.squareup.kotlinpoet.KModifier.VARARG
-import com.squareup.kotlinpoet.ParameterSpec
-import com.squareup.kotlinpoet.ParameterizedTypeName.Companion.parameterizedBy
-import com.squareup.kotlinpoet.PropertySpec
-import com.squareup.kotlinpoet.STAR
-import com.squareup.kotlinpoet.TypeName
-import com.squareup.kotlinpoet.TypeVariableName
-import com.squareup.kotlinpoet.WildcardTypeName
+import com.squareup.kotlinpoet.TypeSpec
 import com.squareup.kotlinpoet.asClassName
 import com.squareup.kotlinpoet.asTypeName
-import com.squareup.kotlinpoet.asTypeVariableName
-import com.squareup.kotlinpoet.tag
+import com.squareup.kotlinpoet.classinspector.elements.ElementsClassInspector
+import com.squareup.kotlinpoet.metadata.KotlinPoetMetadataPreview
+import com.squareup.kotlinpoet.metadata.isAbstract
+import com.squareup.kotlinpoet.metadata.isClass
+import com.squareup.kotlinpoet.metadata.isEnum
+import com.squareup.kotlinpoet.metadata.isInner
+import com.squareup.kotlinpoet.metadata.isLocal
+import com.squareup.kotlinpoet.metadata.isSealed
+import com.squareup.kotlinpoet.metadata.specs.ClassInspector
+import com.squareup.kotlinpoet.metadata.specs.toTypeSpec
+import com.squareup.kotlinpoet.metadata.toImmutableKmClass
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonQualifier
 import com.squareup.moshi.kotlin.codegen.api.DelegateKey
@@ -43,264 +40,125 @@ import com.squareup.moshi.kotlin.codegen.api.TargetConstructor
 import com.squareup.moshi.kotlin.codegen.api.TargetParameter
 import com.squareup.moshi.kotlin.codegen.api.TargetProperty
 import com.squareup.moshi.kotlin.codegen.api.TargetType
-import com.squareup.moshi.kotlin.codegen.api.TypeResolver
-import me.eugeniomarletti.kotlin.metadata.KotlinClassMetadata
-import me.eugeniomarletti.kotlin.metadata.KotlinMetadata
-import me.eugeniomarletti.kotlin.metadata.classKind
-import me.eugeniomarletti.kotlin.metadata.declaresDefaultValue
-import me.eugeniomarletti.kotlin.metadata.getPropertyOrNull
-import me.eugeniomarletti.kotlin.metadata.isDataClass
-import me.eugeniomarletti.kotlin.metadata.isInnerClass
-import me.eugeniomarletti.kotlin.metadata.isPrimary
-import me.eugeniomarletti.kotlin.metadata.jvm.getJvmConstructorSignature
-import me.eugeniomarletti.kotlin.metadata.kotlinMetadata
-import me.eugeniomarletti.kotlin.metadata.modality
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Class
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Modality.ABSTRACT
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Modality.SEALED
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Type
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.TypeParameter
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.TypeParameter.Variance
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility.INTERNAL
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility.LOCAL
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility.PRIVATE
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility.PRIVATE_TO_THIS
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.ProtoBuf.Visibility.PROTECTED
-import me.eugeniomarletti.kotlin.metadata.shadow.metadata.deserialization.NameResolver
-import me.eugeniomarletti.kotlin.metadata.shadow.util.capitalizeDecapitalize.decapitalizeAsciiOnly
-import me.eugeniomarletti.kotlin.metadata.visibility
 import java.lang.annotation.ElementType
 import java.lang.annotation.Retention
 import java.lang.annotation.RetentionPolicy
 import java.lang.annotation.Target
 import javax.annotation.processing.Messager
-import javax.lang.model.element.AnnotationMirror
-import javax.lang.model.element.Element
 import javax.lang.model.element.ElementKind
-import javax.lang.model.element.ExecutableElement
-import javax.lang.model.element.Modifier
-import javax.lang.model.element.Modifier.DEFAULT
-import javax.lang.model.element.Modifier.FINAL
-import javax.lang.model.element.Modifier.NATIVE
-import javax.lang.model.element.Modifier.STATIC
-import javax.lang.model.element.Modifier.SYNCHRONIZED
-import javax.lang.model.element.Modifier.TRANSIENT
-import javax.lang.model.element.Modifier.VOLATILE
 import javax.lang.model.element.TypeElement
-import javax.lang.model.element.VariableElement
-import javax.lang.model.type.TypeVariable
 import javax.lang.model.util.Elements
 import javax.lang.model.util.Types
 import javax.tools.Diagnostic
-import javax.tools.Diagnostic.Kind.ERROR
-import kotlin.reflect.KClass

-private fun TypeParameter.asTypeName(
-    nameResolver: NameResolver,
-    getTypeParameter: (index: Int) -> TypeParameter,
-    resolveAliases: Boolean = false
-): TypeVariableName {
-  val possibleBounds = upperBoundList.map {
-    it.asTypeName(nameResolver, getTypeParameter, resolveAliases)
-  }
-  return if (possibleBounds.isEmpty()) {
-    TypeVariableName(
-        name = nameResolver.getString(name),
-        variance = variance.asKModifier())
-  } else {
-    TypeVariableName(
-        name = nameResolver.getString(name),
-        bounds = *possibleBounds.toTypedArray(),
-        variance = variance.asKModifier())
-  }
+private val JSON_QUALIFIER = JsonQualifier::class.java
+private val JSON = Json::class.asClassName()
+private val OBJECT_CLASS = ClassName("java.lang", "Object")
+private val VISIBILITY_MODIFIERS = setOf(
+    KModifier.INTERNAL,
+    KModifier.PRIVATE,
+    KModifier.PROTECTED,
+    KModifier.PUBLIC
+)
+
+private fun Collection<KModifier>.visibility(): KModifier {
+  return find { it in VISIBILITY_MODIFIERS } ?: KModifier.PUBLIC
 }

-private fun TypeParameter.Variance.asKModifier(): KModifier? {
-  return when (this) {
-    Variance.IN -> KModifier.IN
-    Variance.OUT -> KModifier.OUT
-    Variance.INV -> null
-  }
-}
-
-private fun Visibility?.asKModifier(): KModifier {
-  return when (this) {
-    INTERNAL -> KModifier.INTERNAL
-    PRIVATE -> KModifier.PRIVATE
-    PROTECTED -> KModifier.PROTECTED
-    Visibility.PUBLIC -> KModifier.PUBLIC
-    PRIVATE_TO_THIS -> KModifier.PRIVATE
-    LOCAL -> KModifier.PRIVATE
-    else -> PUBLIC
-  }
-}
-
-/**
- * Returns the TypeName of this type as it would be seen in the source code, including nullability
- * and generic type parameters.
- *
- * @param [nameResolver] a [NameResolver] instance from the source proto
- * @param [getTypeParameter] a function that returns the type parameter for the given index. **Only
- *     called if [ProtoBuf.Type.hasTypeParameter] is true!**
- */
-private fun Type.asTypeName(
-    nameResolver: NameResolver,
-    getTypeParameter: (index: Int) -> TypeParameter,
-    useAbbreviatedType: Boolean = true
-): TypeName {
-
-  val argumentList = when {
-    useAbbreviatedType && hasAbbreviatedType() -> abbreviatedType.argumentList
-    else -> argumentList
-  }
-
-  if (hasFlexibleUpperBound()) {
-    return WildcardTypeName.producerOf(
-        flexibleUpperBound.asTypeName(nameResolver, getTypeParameter, useAbbreviatedType))
-        .copy(nullable = nullable)
-  } else if (hasOuterType()) {
-    return WildcardTypeName.consumerOf(
-        outerType.asTypeName(nameResolver, getTypeParameter, useAbbreviatedType))
-        .copy(nullable = nullable)
-  }
-
-  val realType = when {
-    hasTypeParameter() -> return getTypeParameter(typeParameter)
-        .asTypeName(nameResolver, getTypeParameter, useAbbreviatedType)
-        .copy(nullable = nullable)
-    hasTypeParameterName() -> typeParameterName
-    useAbbreviatedType && hasAbbreviatedType() -> abbreviatedType.typeAliasName
-    else -> className
-  }
-
-  var typeName: TypeName =
-      ClassName.bestGuess(nameResolver.getString(realType)
-          .replace("/", "."))
-
-  if (argumentList.isNotEmpty()) {
-    val remappedArgs: Array<TypeName> = argumentList.map { argumentType ->
-      val nullableProjection = if (argumentType.hasProjection()) {
-        argumentType.projection
-      } else null
-      if (argumentType.hasType()) {
-        argumentType.type.asTypeName(nameResolver, getTypeParameter, useAbbreviatedType)
-            .let { argumentTypeName ->
-              nullableProjection?.let { projection ->
-                when (projection) {
-                  Type.Argument.Projection.IN -> WildcardTypeName.consumerOf(argumentTypeName)
-                  Type.Argument.Projection.OUT -> WildcardTypeName.producerOf(argumentTypeName)
-                  Type.Argument.Projection.STAR -> STAR
-                  Type.Argument.Projection.INV -> TODO("INV projection is unsupported")
-                }
-              } ?: argumentTypeName
-            }
-      } else {
-        STAR
-      }
-    }.toTypedArray()
-    typeName = (typeName as ClassName).parameterizedBy(*remappedArgs)
-  }
-
-  return typeName.copy(nullable = nullable)
-}
-
-internal fun primaryConstructor(metadata: KotlinClassMetadata,
-    elements: Elements): TargetConstructor {
-  val (nameResolver, classProto) = metadata.data
-
-  // TODO allow custom constructor
-  val proto = classProto.constructorList
-      .single { it.isPrimary }
-  val constructorJvmSignature = proto.getJvmConstructorSignature(
-      nameResolver, classProto.typeTable)
-  val element = classProto.fqName
-      .let(nameResolver::getString)
-      .replace('/', '.')
-      .let(elements::getTypeElement)
-      .enclosedElements
-      .mapNotNull {
-        it.takeIf { it.kind == ElementKind.CONSTRUCTOR }?.let { it as ExecutableElement }
-      }
-      .first()
-  // TODO Temporary until JVM method signature matching is better
-  //  .single { it.jvmMethodSignature == constructorJvmSignature }
+@KotlinPoetMetadataPreview
+internal fun primaryConstructor(kotlinApi: TypeSpec, elements: Elements): TargetConstructor? {
+  val primaryConstructor = kotlinApi.primaryConstructor ?: return null

  val parameters = mutableMapOf<String, TargetParameter>()
-  for (parameter in proto.valueParameterList) {
-    val name = nameResolver.getString(parameter.name)
-    val index = proto.valueParameterList.indexOf(parameter)
-    val paramElement = element.parameters[index]
+  for ((index, parameter) in primaryConstructor.parameters.withIndex()) {
+    val name = parameter.name
    parameters[name] = TargetParameter(
        name = name,
        index = index,
-        hasDefault = parameter.declaresDefaultValue,
-        qualifiers = paramElement.qualifiers.mapTo(mutableSetOf(), AnnotationMirror::asAnnotationSpec),
-        jsonName = paramElement.jsonName ?: name,
-        tags = mapOf(VariableElement::class to paramElement)
+        hasDefault = parameter.defaultValue != null,
+        qualifiers = parameter.annotations.qualifiers(elements),
+        jsonName = parameter.annotations.jsonName() ?: name.escapeDollarSigns()
    )
  }

-  return TargetConstructor(parameters,
-      proto.visibility.asKModifier())
+  return TargetConstructor(parameters, primaryConstructor.modifiers.visibility())
 }

-private val OBJECT_CLASS = ClassName("java.lang", "Object")
-
 /** Returns a target type for `element`, or null if it cannot be used with code gen. */
+@KotlinPoetMetadataPreview
 internal fun targetType(messager: Messager,
    elements: Elements,
    types: Types,
-    element: Element): TargetType? {
-  val typeMetadata: KotlinMetadata? = element.kotlinMetadata
-  if (element !is TypeElement || typeMetadata !is KotlinClassMetadata) {
+    element: TypeElement): TargetType? {
+  val typeMetadata = element.getAnnotation(Metadata::class.java)
+  if (typeMetadata == null) {
    messager.printMessage(
-        ERROR, "@JsonClass can't be applied to $element: must be a Kotlin class", element)
+        Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must be a Kotlin class",
+        element)
    return null
  }

-  val proto = typeMetadata.data.classProto
-  when {
-    proto.classKind == Class.Kind.ENUM_CLASS -> {
+  val kmClass = try {
+    typeMetadata.toImmutableKmClass()
+  } catch (e: UnsupportedOperationException) {
    messager.printMessage(
-          ERROR,
+        Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must be a Class type",
+        element)
+    return null
+  }
+
+  when {
+    kmClass.isEnum -> {
+      messager.printMessage(
+          Diagnostic.Kind.ERROR,
          "@JsonClass with 'generateAdapter = \"true\"' can't be applied to $element: code gen for enums is not supported or necessary",
          element)
      return null
    }
-    proto.classKind != Class.Kind.CLASS -> {
+    !kmClass.isClass -> {
      messager.printMessage(
-          ERROR, "@JsonClass can't be applied to $element: must be a Kotlin class", element)
+          Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must be a Kotlin class",
+          element)
      return null
    }
-    proto.isInnerClass -> {
+    kmClass.isInner -> {
      messager.printMessage(
-          ERROR, "@JsonClass can't be applied to $element: must not be an inner class", element)
+          Diagnostic.Kind.ERROR,
+          "@JsonClass can't be applied to $element: must not be an inner class", element)
      return null
    }
-    proto.modality == SEALED -> {
+    kmClass.isSealed -> {
      messager.printMessage(
-          ERROR, "@JsonClass can't be applied to $element: must not be sealed", element)
+          Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must not be sealed", element)
      return null
    }
-    proto.modality == ABSTRACT -> {
+    kmClass.isAbstract -> {
      messager.printMessage(
-          ERROR, "@JsonClass can't be applied to $element: must not be abstract", element)
+          Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must not be abstract",
+          element)
      return null
    }
-    proto.visibility == LOCAL -> {
+    kmClass.isLocal -> {
      messager.printMessage(
-          ERROR, "@JsonClass can't be applied to $element: must not be local", element)
+          Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: must not be local",
+          element)
      return null
    }
  }

-  val typeVariables = genericTypeNames(proto, typeMetadata.data.nameResolver)
+  val elementHandler = ElementsClassInspector.create(elements, types)
+  val kotlinApi = kmClass.toTypeSpec(elementHandler)
+  val typeVariables = kotlinApi.typeVariables
  val appliedType = AppliedType.get(element)

-  val constructor = primaryConstructor(typeMetadata, elements)
+  val constructor = primaryConstructor(kotlinApi, elements)
+  if (constructor == null) {
+    messager.printMessage(Diagnostic.Kind.ERROR, "No primary constructor found on $element",
+        element)
+    return null
+  }
  if (constructor.visibility != KModifier.INTERNAL && constructor.visibility != KModifier.PUBLIC) {
-    messager.printMessage(ERROR, "@JsonClass can't be applied to $element: " +
+    messager.printMessage(Diagnostic.Kind.ERROR, "@JsonClass can't be applied to $element: " +
        "primary constructor is not internal or public", element)
    return null
  }
@@ -313,14 +171,19 @@ internal fun targetType(messager: Messager,
    if (supertype.element.kind != ElementKind.CLASS) {
      continue // Don't load properties for interface types.
    }
-    if (supertype.element.kotlinMetadata == null) {
-      messager.printMessage(ERROR,
+    if (supertype.element.getAnnotation(Metadata::class.java) == null) {
+      messager.printMessage(Diagnostic.Kind.ERROR,
          "@JsonClass can't be applied to $element: supertype $supertype is not a Kotlin type",
          element)
      return null
    }
-    val supertypeProperties = declaredProperties(
-        supertype.element, supertype.resolver, constructor)
+    val supertypeProperties = if (supertype.element == element) {
+      // We've already parsed this api above, reuse it
+      declaredProperties(supertype.element, constructor, elementHandler, kotlinApi)
+    } else {
+      declaredProperties(
+          supertype.element, constructor, elementHandler)
+    }
    for ((name, property) in supertypeProperties) {
      properties.putIfAbsent(name, property)
    }
@@ -330,224 +193,37 @@ internal fun targetType(messager: Messager,
      constructor = constructor,
      properties = properties,
      typeVariables = typeVariables,
-      isDataClass = proto.isDataClass,
-      visibility = proto.visibility.asKModifier())
+      isDataClass = KModifier.DATA in kotlinApi.modifiers,
+      visibility = kotlinApi.modifiers.visibility())
 }

 /** Returns the properties declared by `typeElement`. */
+@KotlinPoetMetadataPreview
 private fun declaredProperties(
    typeElement: TypeElement,
-    typeResolver: TypeResolver,
-    constructor: TargetConstructor
+    constructor: TargetConstructor,
+    elementHandler: ClassInspector,
+    kotlinApi: TypeSpec = typeElement.toTypeSpec(elementHandler)
 ): Map<String, TargetProperty> {
-  val typeMetadata: KotlinClassMetadata = typeElement.kotlinMetadata as KotlinClassMetadata
-  val nameResolver = typeMetadata.data.nameResolver
-  val classProto = typeMetadata.data.classProto
-
-  val annotationHolders = mutableMapOf<String, ExecutableElement>()
-  val fields = mutableMapOf<String, VariableElement>()
-  val setters = mutableMapOf<String, ExecutableElement>()
-  val getters = mutableMapOf<String, ExecutableElement>()
-  for (element in typeElement.enclosedElements) {
-    if (element is VariableElement) {
-      fields[element.name] = element
-    } else if (element is ExecutableElement) {
-      when {
-        element.name.startsWith("get") -> {
-          val name = element.name.substring("get".length).decapitalizeAsciiOnly()
-          getters[name] = element
-        }
-        element.name.startsWith("is") -> {
-          val name = element.name.substring("is".length).decapitalizeAsciiOnly()
-          getters[name] = element
-        }
-        element.name.startsWith("set") -> {
-          val name = element.name.substring("set".length).decapitalizeAsciiOnly()
-          setters[name] = element
-        }
-      }
-
-      val propertyProto = typeMetadata.data.getPropertyOrNull(element)
-      if (propertyProto != null) {
-        val name = nameResolver.getString(propertyProto.name)
-        annotationHolders[name] = element
-      }
-    }
-  }

  val result = mutableMapOf<String, TargetProperty>()
-  for (property in classProto.propertyList) {
-    val name = nameResolver.getString(property.name)
-    val type = typeResolver.resolve(property.returnType.asTypeName(
-        nameResolver, classProto::getTypeParameter, false))
+  for (property in kotlinApi.propertySpecs) {
+    val name = property.name
    val parameter = constructor.parameters[name]
-    val fieldElement = fields[name]
-    val annotationHolder = annotationHolders[name]
-    // Used for setter/getter/is lookups. Guaranteed to be safe because kotlin doesn't allow you to
-    // have both "AAA" and "aAA".
-    val decapitalizedName = name.decapitalizeAsciiOnly()
-    result[name] = TargetProperty(name = name,
-        type = type,
+    result[name] = TargetProperty(
+        propertySpec = property,
        parameter = parameter,
-        annotationHolder = annotationHolder?.asFunSpec(),
-        field = fieldElement?.asPropertySpec(),
-        setter = setters[decapitalizedName]?.asFunSpec(),
-        getter = getters[decapitalizedName]?.asFunSpec(),
-        visibility = property.visibility.asKModifier(),
-        jsonName = jsonName(
-            fieldElement = fieldElement,
-            parameter = parameter,
-            annotationHolder = annotationHolder,
-            name = name
-        )
+        visibility = property.modifiers.visibility(),
+        jsonName = parameter?.jsonName ?: property.annotations.jsonName()
+        ?: name.escapeDollarSigns()
    )
  }

  return result
 }

-/** Returns the @Json name of this property, or this property's name if none is provided. */
-private fun jsonName(
-    fieldElement: Element?,
-    parameter: TargetParameter?,
-    annotationHolder: ExecutableElement?,
-    name: String): String {
-  val fieldJsonName = fieldElement.jsonName
-  val annotationHolderJsonName = annotationHolder.jsonName
-  val parameterJsonName = parameter?.jsonName
-
-  return when {
-    fieldJsonName != null -> fieldJsonName
-    annotationHolderJsonName != null -> annotationHolderJsonName
-    parameterJsonName != null -> parameterJsonName
-    else -> name
-  }
-}
-
-private val Element.name get() = simpleName.toString()
-
-private fun genericTypeNames(proto: Class, nameResolver: NameResolver): List<TypeVariableName> {
-  return proto.typeParameterList.map { typeParameter ->
-    val possibleBounds = typeParameter.upperBoundList
-        .map { it.asTypeName(nameResolver, proto::getTypeParameter, false) }
-    val typeVar = if (possibleBounds.isEmpty()) {
-      TypeVariableName(
-          name = nameResolver.getString(typeParameter.name),
-          variance = typeParameter.varianceModifier)
-    } else {
-      TypeVariableName(
-          name = nameResolver.getString(typeParameter.name),
-          bounds = *possibleBounds.toTypedArray(),
-          variance = typeParameter.varianceModifier)
-    }
-    return@map typeVar.copy(reified = typeParameter.reified)
-  }
-}
-
-private val TypeParameter.varianceModifier: KModifier?
-  get() {
-    return variance.asKModifier().let {
-      // We don't redeclare out variance here
-      if (it == KModifier.OUT) {
-        null
-      } else {
-        it
-      }
-    }
-  }
-
-/**
- * Returns a new [PropertySpec] representation of [this].
- *
- * This will copy its name, type, visibility modifiers, constant value, and annotations. Note that
- * Java modifiers that correspond to annotations in kotlin will be added as well (`volatile`,
- * `transient`, etc`.
- *
- * The original `field` ([this]) is stored in [PropertySpec.tag].
- */
-internal fun VariableElement.asPropertySpec(asJvmField: Boolean = false): PropertySpec {
-  require(kind == ElementKind.FIELD) {
-    "Must be a field!"
-  }
-  val modifiers: Set<Modifier> = modifiers
-  val fieldName = simpleName.toString()
-  val propertyBuilder = PropertySpec.builder(fieldName, asType().asTypeName())
-  propertyBuilder.addModifiers(*modifiers.mapNotNull { it.asKModifier() }.toTypedArray())
-  constantValue?.let {
-    if (it is String) {
-      propertyBuilder.initializer(CodeBlock.of("%S", it))
-    } else {
-      propertyBuilder.initializer(CodeBlock.of("%L", it))
-    }
-  }
-  propertyBuilder.addAnnotations(annotationMirrors.map(AnnotationMirror::asAnnotationSpec))
-  propertyBuilder.addAnnotations(modifiers.mapNotNull { it.asAnnotation() })
-  propertyBuilder.tag(this)
-  if (asJvmField && KModifier.PRIVATE !in propertyBuilder.modifiers) {
-    propertyBuilder.addAnnotation(JvmField::class)
-  }
-  return propertyBuilder.build()
-}
-
-/**
- * Returns a new [AnnotationSpec] representation of [this].
- *
- * Identical and delegates to [AnnotationSpec.get], but the original `mirror` is also stored
- * in [AnnotationSpec.tag].
- */
-internal fun AnnotationMirror.asAnnotationSpec(): AnnotationSpec {
-  return AnnotationSpec.get(this)
-      .toBuilder()
-      .tag(MoreTypes.asTypeElement(annotationType))
-      .build()
-}
-
-/**
- * Returns a new [FunSpec] representation of [this].
- *
- * This will copy its visibility modifiers, type parameters, return type, name, parameters, and
- * throws declarations.
- *
- * The original `method` ([this]) is stored in [FunSpec.tag].
- *
- * Nearly identical to [FunSpec.overriding], but no override modifier is added nor are checks around
- * overridability done
- */
-internal fun ExecutableElement.asFunSpec(): FunSpec {
-  var modifiers: Set<Modifier> = modifiers
-  val methodName = simpleName.toString()
-  val funBuilder = FunSpec.builder(methodName)
-
-  modifiers = modifiers.toMutableSet()
-  funBuilder.jvmModifiers(modifiers)
-
-  typeParameters
-      .map { it.asType() as TypeVariable }
-      .map { it.asTypeVariableName() }
-      .forEach { funBuilder.addTypeVariable(it) }
-
-  funBuilder.returns(returnType.asTypeName())
-  funBuilder.addParameters(ParameterSpec.parametersOf(this))
-  if (isVarArgs) {
-    funBuilder.parameters[funBuilder.parameters.lastIndex] = funBuilder.parameters.last()
-        .toBuilder()
-        .addModifiers(VARARG)
-        .build()
-  }
-
-  if (thrownTypes.isNotEmpty()) {
-    val throwsValueString = thrownTypes.joinToString { "%T::class" }
-    funBuilder.addAnnotation(AnnotationSpec.builder(Throws::class)
-        .addMember(throwsValueString, *thrownTypes.toTypedArray())
-        .build())
-  }
-
-  funBuilder.tag(this)
-  return funBuilder.build()
-}
-
-private val TargetProperty.isTransient get() = field != null && field.annotations.any { it.className == Transient::class.asClassName() }
-private val TargetProperty.isSettable get() = setter != null || parameter != null
+private val TargetProperty.isTransient get() = propertySpec.annotations.any { it.className == Transient::class.asClassName() }
+private val TargetProperty.isSettable get() = propertySpec.mutable || parameter != null
 private val TargetProperty.isVisible: Boolean
  get() {
    return visibility == KModifier.INTERNAL
@@ -559,26 +235,24 @@ private val TargetProperty.isVisible: Boolean
 * Returns a generator for this property, or null if either there is an error and this property
 * cannot be used with code gen, or if no codegen is necessary for this property.
 */
-internal fun TargetProperty.generator(messager: Messager): PropertyGenerator? {
-  val element = field?.tag<VariableElement>() ?: setter?.tag<ExecutableElement>()
-  ?: getter!!.tag<ExecutableElement>()
+internal fun TargetProperty.generator(
+    messager: Messager,
+    sourceElement: TypeElement,
+    elements: Elements
+): PropertyGenerator? {
  if (isTransient) {
    if (!hasDefault) {
-      element?.let {
      messager.printMessage(
-            Diagnostic.Kind.ERROR, "No default value for transient property ${this}",
-            it)
-      }
+          Diagnostic.Kind.ERROR, "No default value for transient property $name",
+          sourceElement)
      return null
    }
    return PropertyGenerator(this, DelegateKey(type, emptyList()), true)
  }

  if (!isVisible) {
-    element?.let {
-      messager.printMessage(Diagnostic.Kind.ERROR, "property ${this} is not visible",
-          it)
-    }
+    messager.printMessage(Diagnostic.Kind.ERROR, "property $name is not visible",
+        sourceElement)
    return null
  }

@@ -586,10 +260,12 @@ internal fun TargetProperty.generator(messager: Messager): PropertyGenerator? {
    return null // This property is not settable. Ignore it.
  }

-  val jsonQualifierMirrors = jsonQualifiers(element)
-  for (jsonQualifier in jsonQualifierMirrors) {
+  // Merge parameter and property annotations
+  val qualifiers = parameter?.qualifiers.orEmpty() + propertySpec.annotations.qualifiers(elements)
+  for (jsonQualifier in qualifiers) {
    // Check Java types since that covers both Java and Kotlin annotations.
-    val annotationElement = jsonQualifier.tag<TypeElement>() ?: continue
+    val annotationElement = elements.getTypeElement(jsonQualifier.className.canonicalName)
+        ?: continue
    annotationElement.getAnnotation(Retention::class.java)?.let {
      if (it.value != RetentionPolicy.RUNTIME) {
        messager.printMessage(Diagnostic.Kind.ERROR,
@@ -604,7 +280,7 @@ internal fun TargetProperty.generator(messager: Messager): PropertyGenerator? {
    }
  }

-  val jsonQualifierSpecs = jsonQualifierMirrors.map {
+  val jsonQualifierSpecs = qualifiers.map {
    it.toBuilder()
        .useSiteTarget(AnnotationSpec.UseSiteTarget.FIELD)
        .build()
@@ -614,57 +290,21 @@ internal fun TargetProperty.generator(messager: Messager): PropertyGenerator? {
      DelegateKey(type, jsonQualifierSpecs))
 }

-/** Returns the JsonQualifiers on the field and parameter of this property. */
-private fun TargetProperty.jsonQualifiers(element: Element?): Set<AnnotationSpec> {
-  val elementQualifiers = element.qualifiers
-  val annotationHolderQualifiers = annotationHolder?.tag<ExecutableElement>().qualifiers
-  val parameterQualifiers = parameter?.qualifiers.orEmpty()
-
-  // TODO(jwilson): union the qualifiers somehow?
-  return when {
-    elementQualifiers.isNotEmpty() -> elementQualifiers.mapTo(mutableSetOf(), AnnotationMirror::asAnnotationSpec)
-    annotationHolderQualifiers.isNotEmpty() -> annotationHolderQualifiers.mapTo(
-        mutableSetOf(), AnnotationMirror::asAnnotationSpec)
-    parameterQualifiers.isNotEmpty() -> parameterQualifiers
-    else -> setOf()
-  }
-}
-
-private fun Modifier.asKModifier(): KModifier? {
-  return when (this) {
-    Modifier.PUBLIC -> KModifier.PUBLIC
-    Modifier.PROTECTED -> KModifier.PROTECTED
-    Modifier.PRIVATE -> KModifier.PRIVATE
-    Modifier.ABSTRACT -> KModifier.ABSTRACT
-    FINAL -> KModifier.FINAL
-    else -> null
-  }
-}
-
-private fun Modifier.asAnnotation(): AnnotationSpec? {
-  return when (this) {
-    DEFAULT -> JvmDefault::class.asAnnotationSpec()
-    STATIC -> JvmStatic::class.asAnnotationSpec()
-    TRANSIENT -> Transient::class.asAnnotationSpec()
-    VOLATILE -> Volatile::class.asAnnotationSpec()
-    SYNCHRONIZED -> Synchronized::class.asAnnotationSpec()
-    NATIVE -> JvmDefault::class.asAnnotationSpec()
-    else -> null
-  }
-}
-
-private fun <T : Annotation> KClass<T>.asAnnotationSpec(): AnnotationSpec {
-  return AnnotationSpec.builder(this).build()
-}
-
-private val Element?.qualifiers: Set<AnnotationMirror>
-  get() {
+private fun List<AnnotationSpec>?.qualifiers(elements: Elements): Set<AnnotationSpec> {
  if (this == null) return setOf()
-    return AnnotationMirrors.getAnnotatedAnnotations(this, JsonQualifier::class.java)
+  return filterTo(mutableSetOf()) {
+    elements.getTypeElement(it.className.toString()).getAnnotation(JSON_QUALIFIER) != null
  }
+}

-private val Element?.jsonName: String?
-  get() {
+/** Gross, but we can't extract values from AnnotationSpecs by member names alone. */
+private fun List<AnnotationSpec>?.jsonName(): String? {
  if (this == null) return null
-    return getAnnotation(Json::class.java)?.name
+  return find { it.className == JSON }?.let {
+    it.members[0].toString().removePrefix("name = \"").removeSuffix("\"")
  }
+}
+
+private fun String.escapeDollarSigns(): String {
+  return replace("\$", "\${\'\$\'}")
+}
--- a/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/JsonClassCodegenProcessorTest.kt
+++ b/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/JsonClassCodegenProcessorTest.kt
@@ -18,6 +18,7 @@ package com.squareup.moshi.kotlin.codegen
 import com.tschuchort.compiletesting.KotlinCompilation
 import com.tschuchort.compiletesting.SourceFile
 import com.tschuchort.compiletesting.SourceFile.Companion.kotlin
+import com.squareup.kotlinpoet.metadata.KotlinPoetMetadataPreview
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.Ignore
 import org.junit.Rule
@@ -25,6 +26,7 @@ import org.junit.Test
 import org.junit.rules.TemporaryFolder

 /** Execute kotlinc to confirm that either files are generated or errors are printed. */
+@UseExperimental(KotlinPoetMetadataPreview::class)
 class JsonClassCodegenProcessorTest {
  @Rule @JvmField var temporaryFolder: TemporaryFolder = TemporaryFolder()

--- a/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/TypeResolverTest.kt
+++ b/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/TypeResolverTest.kt
@@ -1,47 +0,0 @@
-/*
- * Copyright (C) 2018 Square, Inc.
- *
- * 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 com.squareup.moshi.kotlin.codegen
-
-import com.google.common.truth.Truth.assertThat
-import com.squareup.kotlinpoet.ParameterizedTypeName.Companion.plusParameter
-import com.squareup.kotlinpoet.WildcardTypeName
-import com.squareup.kotlinpoet.asClassName
-import com.squareup.moshi.kotlin.codegen.api.TypeResolver
-import org.junit.Test
-
-class TypeResolverTest {
-  private val resolver = TypeResolver()
-
-  @Test
-  fun ensureClassNameNullabilityIsPreserved() {
-    assertThat(resolver.resolve(Int::class.asClassName().copy(nullable = true)).isNullable).isTrue()
-  }
-
-  @Test
-  fun ensureParameterizedNullabilityIsPreserved() {
-    val nullableTypeName = List::class.plusParameter(String::class).copy(nullable = true)
-
-    assertThat(resolver.resolve(nullableTypeName).isNullable).isTrue()
-  }
-
-  @Test
-  fun ensureWildcardNullabilityIsPreserved() {
-    val nullableTypeName = WildcardTypeName.producerOf(List::class.asClassName())
-        .copy(nullable = true)
-
-    assertThat(resolver.resolve(nullableTypeName).isNullable).isTrue()
-  }
-}
--- a/pom.xml
+++ b/pom.xml
@@ -31,15 +31,13 @@
    <java.version>1.7</java.version>

    <!-- Dependencies -->
-    <auto-common.version>0.10</auto-common.version>
    <auto-service.version>1.0-rc5</auto-service.version>
    <dokka.version>0.9.17</dokka.version>
    <incap.version>0.2</incap.version>
    <okio.version>1.16.0</okio.version>
    <okio2.version>2.1.0</okio2.version>
    <kotlin.version>1.3.40</kotlin.version>
-    <kotlinpoet.version>1.3.0</kotlinpoet.version>
-    <kotlin-metadata.version>1.4.0</kotlin-metadata.version>
+    <kotlinpoet.version>1.4.0</kotlinpoet.version>
    <maven-assembly.version>3.1.0</maven-assembly.version>

    <!-- Test Dependencies -->
@@ -118,11 +116,6 @@
        <artifactId>kotlin-annotation-processing-embeddable</artifactId>
        <version>${kotlin.version}</version>
      </dependency>
-      <dependency>
-        <groupId>me.eugeniomarletti.kotlin.metadata</groupId>
-        <artifactId>kotlin-metadata</artifactId>
-        <version>${kotlin-metadata.version}</version>
-      </dependency>
      <dependency>
        <groupId>com.google.testing.compile</groupId>
        <artifactId>compile-testing</artifactId>