Support direct annotation instantiation in code gen on Kotlin 1.6 (#1390)

2025-10-18 23:49:21 +08:00 · 2021-10-22 13:43:09 -04:00
parent a9eaa849e5
commit b8fbe38118
17 changed files with 396 additions and 171 deletions
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,13 +4,24 @@ on: [push, pull_request]

 jobs:
  build:
-    name: 'Java ${{ matrix.java-version }} | KSP ${{ matrix.use-ksp }}'
+    name: 'Java ${{ matrix.java-version }} | Kotlin ${{ matrix.kotlin-version }} | KSP ${{ matrix.use-ksp }}'
    runs-on: ubuntu-latest

    strategy:
      fail-fast: false
      matrix:
        use-ksp: [ true, false ]
+        kotlin-version: [ '1.5.31', '1.6.0-RC' ]
+        ksp-version: [ '1.5.31-1.0.0', '1.6.0-RC-1.0.0' ]
+        exclude:
+          - kotlin-version: '1.5.31'
+            ksp-version: '1.6.0-RC-1.0.0'
+          - kotlin-version: '1.6.0-RC'
+            ksp-version: '1.5.31-1.0.0'
+
+    env:
+      MOSHI_KOTLIN_VERSION: '${{ matrix.kotlin-version }}'
+      MOSHI_KSP_VERSION: '${{ matrix.ksp-version }}'

    steps:
      - name: Checkout
@@ -36,8 +47,8 @@ jobs:
          java-version: '17'

      - name: Test
-        run: ./gradlew build check --stacktrace -PuseKsp=${{ matrix.use-ksp }}
+        run: ./gradlew build check --stacktrace -PuseKsp=${{ matrix.use-ksp }} -PkotlinVersion=${{ matrix.kotlin-version }}

      - name: Publish (default branch only)
-        if: github.repository == 'square/moshi' && github.ref == 'refs/heads/master'
+        if: github.repository == 'square/moshi' && github.ref == 'refs/heads/master' && matrix.kotlin-version == '1.5.31' && matrix.use-ksp == 'false'
        run: ./gradlew publish -PmavenCentralUsername=${{ secrets.SONATYPE_NEXUS_USERNAME }} -PmavenCentralPassword=${{ secrets.SONATYPE_NEXUS_PASSWORD }} --stacktrace
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -23,7 +23,12 @@ import java.net.URL

 buildscript {
  dependencies {
-    classpath(kotlin("gradle-plugin", version = libs.versions.kotlin.get()))
+    val kotlinVersion = System.getenv("MOSHI_KOTLIN_VERSION")
+      ?: libs.versions.kotlin.get()
+    val kspVersion = System.getenv("MOSHI_KSP_VERSION")
+      ?: libs.versions.ksp.get()
+    classpath(kotlin("gradle-plugin", version = kotlinVersion))
+    classpath("com.google.devtools.ksp:symbol-processing-gradle-plugin:$kspVersion")
    // https://github.com/melix/japicmp-gradle-plugin/issues/36
    classpath("com.google.guava:guava:28.2-jre")
  }
@@ -125,8 +130,9 @@ subprojects {
  pluginManager.withPlugin("org.jetbrains.kotlin.jvm") {
    tasks.withType<KotlinCompile>().configureEach {
      kotlinOptions {
-        @Suppress("SuspiciousCollectionReassignment")
-        freeCompilerArgs += listOf("-progressive")
+        // TODO re-enable when no longer supporting multiple kotlin versions
+//        @Suppress("SuspiciousCollectionReassignment")
+//        freeCompilerArgs += listOf("-progressive")
        jvmTarget = libs.versions.jvmTarget.get()
      }
    }
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -18,7 +18,7 @@ gjf = "1.11.0"
 jvmTarget = "1.8"
 kotlin = "1.5.31"
 kotlinCompileTesting = "1.4.4"
-kotlinpoet = "1.10.1"
+kotlinpoet = "1.10.2"
 ksp = "1.5.31-1.0.0"
 ktlint = "0.41.0"

--- a/kotlin/codegen/build.gradle.kts
+++ b/kotlin/codegen/build.gradle.kts
@@ -20,7 +20,7 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinCompile

 plugins {
  kotlin("jvm")
-  alias(libs.plugins.ksp)
+  id("com.google.devtools.ksp")
  id("com.vanniktech.maven.publish")
  alias(libs.plugins.mavenShadow)
 }
--- 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
@@ -185,15 +185,19 @@ internal class AdapterGenerator(
    result.addAnnotation(COMMON_SUPPRESS)
    result.addType(generatedAdapter)
    val proguardConfig = if (generateProguardRules) {
-      generatedAdapter.createProguardRule()
+      generatedAdapter.createProguardRule(target.instantiateAnnotations)
    } else {
      null
    }
    return PreparedAdapter(result.build(), proguardConfig)
  }

-  private fun TypeSpec.createProguardRule(): ProguardConfig {
-    val adapterProperties = propertySpecs
+  private fun TypeSpec.createProguardRule(instantiateAnnotations: Boolean): ProguardConfig {
+    val adapterProperties = if (instantiateAnnotations) {
+      // Don't need to do anything special if we instantiate them directly!
+      emptySet()
+    } else {
+      propertySpecs
        .asSequence()
        .filter { prop ->
          prop.type.rawType() == JsonAdapter::class.asClassName()
@@ -205,6 +209,7 @@ internal class AdapterGenerator(
            qualifiers = prop.annotations.mapTo(mutableSetOf()) { it.typeName.rawType() }
          )
        }
+    }

    val adapterConstructorParams = when (requireNotNull(primaryConstructor).parameters.size) {
      1 -> listOf(CN_MOSHI.reflectionName())
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/DelegateKey.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/DelegateKey.kt
@@ -17,6 +17,7 @@ package com.squareup.moshi.kotlin.codegen.api

 import com.squareup.kotlinpoet.AnnotationSpec
 import com.squareup.kotlinpoet.ClassName
+import com.squareup.kotlinpoet.CodeBlock
 import com.squareup.kotlinpoet.KModifier
 import com.squareup.kotlinpoet.MemberName
 import com.squareup.kotlinpoet.NameAllocator
@@ -29,6 +30,7 @@ import com.squareup.kotlinpoet.TypeVariableName
 import com.squareup.kotlinpoet.WildcardTypeName
 import com.squareup.kotlinpoet.asClassName
 import com.squareup.kotlinpoet.asTypeName
+import com.squareup.kotlinpoet.joinToCode
 import com.squareup.moshi.JsonAdapter
 import com.squareup.moshi.Types
 import java.util.Locale
@@ -36,7 +38,8 @@ import java.util.Locale
 /** A JsonAdapter that can be used to encode and decode a particular field. */
 internal data class DelegateKey(
  private val type: TypeName,
-  private val jsonQualifiers: List<AnnotationSpec>
+  private val jsonQualifiers: List<AnnotationSpec>,
+  private val instantiateAnnotations: Boolean
 ) {
  val nullable get() = type.isNullable

@@ -60,8 +63,12 @@ internal data class DelegateKey(
      moshiParameter,
      typeRenderer.render(type)
    )
+
    val (initializerString, args) = when {
      jsonQualifiers.isEmpty() -> ", %M()" to arrayOf(MemberName("kotlin.collections", "emptySet"))
+      instantiateAnnotations -> {
+        ", setOf(%L)" to arrayOf(jsonQualifiers.map { it.asInstantiationExpression() }.joinToCode())
+      }
      else -> {
        ", %T.getFieldJsonQualifierAnnotations(javaClass, " +
          "%S)" to arrayOf(Types::class.asTypeName(), adapterName)
@@ -70,12 +77,25 @@ internal data class DelegateKey(
    val finalArgs = arrayOf(*standardArgs, *args, propertyName)

    return PropertySpec.builder(adapterName, adapterTypeName, KModifier.PRIVATE)
-      .addAnnotations(jsonQualifiers)
+      .apply {
+        if (!instantiateAnnotations) {
+          addAnnotations(jsonQualifiers)
+        }
+      }
      .initializer("%N.adapter(%L$initializerString, %S)", *finalArgs)
      .build()
  }
 }

+private fun AnnotationSpec.asInstantiationExpression(): CodeBlock {
+  // <Type>(args)
+  return CodeBlock.of(
+    "%T(%L)",
+    typeName,
+    members.joinToCode()
+  )
+}
+
 /**
 * Returns a suggested variable name derived from a list of type names. This just concatenates,
 * yielding types like MapOfStringLong.
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/Options.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/Options.kt
@@ -36,6 +36,14 @@ internal object Options {
   */
  const val OPTION_GENERATE_PROGUARD_RULES: String = "moshi.generateProguardRules"

+  /**
+   * This boolean processing option controls whether or not Moshi will directly instantiate
+   * JsonQualifier annotations in Kotlin 1.6+. Note that this is enabled by default in Kotlin 1.6
+   * but can be disabled to restore the legacy behavior of storing annotations on generated adapter
+   * fields and looking them up reflectively.
+   */
+  const val OPTION_INSTANTIATE_ANNOTATIONS: String = "moshi.instantiateAnnotations"
+
  val POSSIBLE_GENERATED_NAMES = arrayOf(
    ClassName("javax.annotation.processing", "Generated"),
    ClassName("javax.annotation", "Generated")
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetType.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/api/TargetType.kt
@@ -26,7 +26,8 @@ internal data class TargetType(
  val properties: Map<String, TargetProperty>,
  val typeVariables: List<TypeVariableName>,
  val isDataClass: Boolean,
-  val visibility: KModifier
+  val visibility: KModifier,
+  val instantiateAnnotations: Boolean
 ) {

  init {
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt
@@ -23,6 +23,7 @@ import com.squareup.moshi.JsonClass
 import com.squareup.moshi.kotlin.codegen.api.AdapterGenerator
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATED
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATE_PROGUARD_RULES
+import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_INSTANTIATE_ANNOTATIONS
 import com.squareup.moshi.kotlin.codegen.api.Options.POSSIBLE_GENERATED_NAMES
 import com.squareup.moshi.kotlin.codegen.api.ProguardConfig
 import com.squareup.moshi.kotlin.codegen.api.PropertyGenerator
@@ -59,6 +60,7 @@ public class JsonClassCodegenProcessor : AbstractProcessor() {
  private val annotation = JsonClass::class.java
  private var generatedType: ClassName? = null
  private var generateProguardRules: Boolean = true
+  private var instantiateAnnotations: Boolean = true

  override fun getSupportedAnnotationTypes(): Set<String> = setOf(annotation.canonicalName)

@@ -76,6 +78,7 @@ public class JsonClassCodegenProcessor : AbstractProcessor() {
    }

    generateProguardRules = processingEnv.options[OPTION_GENERATE_PROGUARD_RULES]?.toBooleanStrictOrNull() ?: true
+    instantiateAnnotations = processingEnv.options[OPTION_INSTANTIATE_ANNOTATIONS]?.toBooleanStrictOrNull() ?: true

    this.types = processingEnv.typeUtils
    this.elements = processingEnv.elementUtils
@@ -135,11 +138,18 @@ public class JsonClassCodegenProcessor : AbstractProcessor() {
    element: TypeElement,
    cachedClassInspector: MoshiCachedClassInspector
  ): AdapterGenerator? {
-    val type = targetType(messager, elements, types, element, cachedClassInspector) ?: return null
+    val type = targetType(
+      messager,
+      elements,
+      types,
+      element,
+      cachedClassInspector,
+      instantiateAnnotations
+    ) ?: return null

    val properties = mutableMapOf<String, PropertyGenerator>()
    for (property in type.properties.values) {
-      val generator = property.generator(messager, element, elements)
+      val generator = property.generator(messager, element, elements, type.instantiateAnnotations)
      if (generator != null) {
        properties[property.name] = generator
      }
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt
@@ -71,6 +71,7 @@ private val VISIBILITY_MODIFIERS = setOf(
  KModifier.PROTECTED,
  KModifier.PUBLIC
 )
+private val ANNOTATION_INSTANTIATION_MIN_VERSION = KotlinVersion(1, 6, 0)

 private fun Collection<KModifier>.visibility(): KModifier {
  return find { it in VISIBILITY_MODIFIERS } ?: KModifier.PUBLIC
@@ -122,7 +123,8 @@ internal fun targetType(
  elements: Elements,
  types: Types,
  element: TypeElement,
-  cachedClassInspector: MoshiCachedClassInspector
+  cachedClassInspector: MoshiCachedClassInspector,
+  instantiateAnnotationsEnabled: Boolean
 ): TargetType? {
  val typeMetadata = element.getAnnotation(Metadata::class.java)
  if (typeMetadata == null) {
@@ -204,6 +206,11 @@ internal fun targetType(
    }
  }

+  val instantiateAnnotations = instantiateAnnotationsEnabled && run {
+    val (major, minor, patch) = typeMetadata.metadataVersion
+    val languageVersion = KotlinVersion(major, minor, patch)
+    languageVersion >= ANNOTATION_INSTANTIATION_MIN_VERSION
+  }
  val kotlinApi = cachedClassInspector.toTypeSpec(kmClass)
  val typeVariables = kotlinApi.typeVariables
  val appliedType = AppliedType.get(element)
@@ -319,7 +326,8 @@ internal fun targetType(
    properties = properties,
    typeVariables = typeVariables,
    isDataClass = KModifier.DATA in kotlinApi.modifiers,
-    visibility = resolvedVisibility
+    visibility = resolvedVisibility,
+    instantiateAnnotations = instantiateAnnotations
  )
 }

@@ -418,7 +426,8 @@ private val TargetProperty.isVisible: Boolean
 internal fun TargetProperty.generator(
  messager: Messager,
  sourceElement: TypeElement,
-  elements: Elements
+  elements: Elements,
+  instantiateAnnotations: Boolean
 ): PropertyGenerator? {
  if (isTransient) {
    if (!hasDefault) {
@@ -429,7 +438,7 @@ internal fun TargetProperty.generator(
      )
      return null
    }
-    return PropertyGenerator(this, DelegateKey(type, emptyList()), true)
+    return PropertyGenerator(this, DelegateKey(type, emptyList(), instantiateAnnotations), true)
  }

  if (!isVisible) {
@@ -452,6 +461,7 @@ internal fun TargetProperty.generator(
    // Check Java types since that covers both Java and Kotlin annotations.
    val annotationElement = elements.getTypeElement(qualifierRawType.canonicalName)
      ?: continue
+
    annotationElement.getAnnotation(Retention::class.java)?.let {
      if (it.value != RetentionPolicy.RUNTIME) {
        messager.printMessage(
@@ -460,6 +470,7 @@ internal fun TargetProperty.generator(
        )
      }
    }
+    if (!instantiateAnnotations) {
      annotationElement.getAnnotation(Target::class.java)?.let {
        if (ElementType.FIELD !in it.value) {
          messager.printMessage(
@@ -469,6 +480,7 @@ internal fun TargetProperty.generator(
        }
      }
    }
+  }

  val jsonQualifierSpecs = qualifiers.map {
    it.toBuilder()
@@ -478,7 +490,7 @@ internal fun TargetProperty.generator(

  return PropertyGenerator(
    this,
-    DelegateKey(type, jsonQualifierSpecs)
+    DelegateKey(type, jsonQualifierSpecs, instantiateAnnotations)
  )
 }

--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorProvider.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorProvider.kt
@@ -34,6 +34,7 @@ import com.squareup.moshi.JsonClass
 import com.squareup.moshi.kotlin.codegen.api.AdapterGenerator
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATED
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATE_PROGUARD_RULES
+import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_INSTANTIATE_ANNOTATIONS
 import com.squareup.moshi.kotlin.codegen.api.Options.POSSIBLE_GENERATED_NAMES
 import com.squareup.moshi.kotlin.codegen.api.ProguardConfig
 import com.squareup.moshi.kotlin.codegen.api.PropertyGenerator
@@ -63,6 +64,8 @@ private class JsonClassSymbolProcessor(
    }
  }
  private val generateProguardRules = environment.options[OPTION_GENERATE_PROGUARD_RULES]?.toBooleanStrictOrNull() ?: true
+  private val instantiateAnnotations = (environment.options[OPTION_INSTANTIATE_ANNOTATIONS]?.toBooleanStrictOrNull() ?: true) &&
+    environment.kotlinVersion.isAtLeast(1, 6)

  override fun process(resolver: Resolver): List<KSAnnotated> {
    val generatedAnnotation = generatedOption?.let {
@@ -122,11 +125,11 @@ private class JsonClassSymbolProcessor(
    resolver: Resolver,
    originalType: KSDeclaration,
  ): AdapterGenerator? {
-    val type = targetType(originalType, resolver, logger) ?: return null
+    val type = targetType(originalType, resolver, logger, instantiateAnnotations) ?: return null

    val properties = mutableMapOf<String, PropertyGenerator>()
    for (property in type.properties.values) {
-      val generator = property.generator(logger, resolver, originalType)
+      val generator = property.generator(logger, resolver, originalType, type.instantiateAnnotations)
      if (generator != null) {
        properties[property.name] = generator
      }
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/KspUtil.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/KspUtil.kt
@@ -69,12 +69,12 @@ private fun addValueToBlock(value: Any, resolver: Resolver, member: CodeBlock.Bu
  when (value) {
    is List<*> -> {
      // Array type
-      member.add("[⇥⇥")
+      member.add("arrayOf(⇥⇥")
      value.forEachIndexed { index, innerValue ->
        if (index > 0) member.add(", ")
        addValueToBlock(innerValue!!, resolver, member)
      }
-      member.add("⇤⇤]")
+      member.add("⇤⇤)")
    }
    is KSType -> {
      val unwrapped = value.unwrapTypeAlias()
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/MoshiApiUtil.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/MoshiApiUtil.kt
@@ -28,17 +28,6 @@ import com.squareup.moshi.kotlin.codegen.api.PropertyGenerator
 import com.squareup.moshi.kotlin.codegen.api.TargetProperty
 import com.squareup.moshi.kotlin.codegen.api.rawType

-private val VISIBILITY_MODIFIERS = setOf(
-  KModifier.INTERNAL,
-  KModifier.PRIVATE,
-  KModifier.PROTECTED,
-  KModifier.PUBLIC
-)
-
-internal fun Collection<KModifier>.visibility(): KModifier {
-  return find { it in VISIBILITY_MODIFIERS } ?: KModifier.PUBLIC
-}
-
 private val TargetProperty.isTransient get() = propertySpec.annotations.any { it.typeName == Transient::class.asClassName() }
 private val TargetProperty.isSettable get() = propertySpec.mutable || parameter != null
 private val TargetProperty.isVisible: Boolean
@@ -55,7 +44,8 @@ private val TargetProperty.isVisible: Boolean
 internal fun TargetProperty.generator(
  logger: KSPLogger,
  resolver: Resolver,
-  originalType: KSDeclaration
+  originalType: KSDeclaration,
+  instantiateAnnotations: Boolean
 ): PropertyGenerator? {
  if (isTransient) {
    if (!hasDefault) {
@@ -65,7 +55,7 @@ internal fun TargetProperty.generator(
      )
      return null
    }
-    return PropertyGenerator(this, DelegateKey(type, emptyList()), true)
+    return PropertyGenerator(this, DelegateKey(type, emptyList(), instantiateAnnotations), true)
  }

  if (!isVisible) {
@@ -93,6 +83,7 @@ internal fun TargetProperty.generator(
          )
        }
      }
+      if (!instantiateAnnotations) {
        annotationElement.findAnnotationWithType<Target>()?.let {
          if (AnnotationTarget.FIELD !in it.allowedTargets) {
            logger.error(
@@ -102,6 +93,7 @@ internal fun TargetProperty.generator(
        }
      }
    }
+  }

  val jsonQualifierSpecs = qualifiers.map {
    it.toBuilder()
@@ -111,7 +103,7 @@ internal fun TargetProperty.generator(

  return PropertyGenerator(
    this,
-    DelegateKey(type, jsonQualifierSpecs)
+    DelegateKey(type, jsonQualifierSpecs, instantiateAnnotations)
  )
 }

--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/TargetTypes.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/ksp/TargetTypes.kt
@@ -58,6 +58,7 @@ internal fun targetType(
  type: KSDeclaration,
  resolver: Resolver,
  logger: KSPLogger,
+  instantiateAnnotations: Boolean
 ): TargetType? {
  if (type !is KSClassDeclaration) {
    logger.error("@JsonClass can't be applied to ${type.qualifiedName?.asString()}: must be a Kotlin class", type)
@@ -152,7 +153,8 @@ internal fun targetType(
    properties = properties,
    typeVariables = typeVariables,
    isDataClass = Modifier.DATA in type.modifiers,
-    visibility = resolvedVisibility
+    visibility = resolvedVisibility,
+    instantiateAnnotations = instantiateAnnotations
  )
 }

--- a/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessorTest.kt
+++ b/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessorTest.kt
@@ -18,9 +18,9 @@ package com.squareup.moshi.kotlin.codegen.apt
 import com.google.common.truth.Truth.assertThat
 import com.squareup.moshi.JsonAdapter
 import com.squareup.moshi.JsonReader
-import com.squareup.moshi.kotlin.codegen.api.Options
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATED
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATE_PROGUARD_RULES
+import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_INSTANTIATE_ANNOTATIONS
 import com.tschuchort.compiletesting.KotlinCompilation
 import com.tschuchort.compiletesting.SourceFile
 import com.tschuchort.compiletesting.SourceFile.Companion.kotlin
@@ -28,6 +28,8 @@ import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
 import org.junit.rules.TemporaryFolder
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized
 import kotlin.reflect.KClass
 import kotlin.reflect.KClassifier
 import kotlin.reflect.KType
@@ -38,7 +40,24 @@ import kotlin.reflect.full.createType
 import kotlin.reflect.full.declaredMemberProperties

 /** Execute kotlinc to confirm that either files are generated or errors are printed. */
-class JsonClassCodegenProcessorTest {
+@RunWith(Parameterized::class)
+class JsonClassCodegenProcessorTest(
+  private val languageVersion: String,
+  private val instantiateAnnotations: Boolean
+) {
+
+  companion object {
+    @JvmStatic
+    @Parameterized.Parameters(name = "languageVersion={0},instantiateAnnotations={1}")
+    fun data(): Collection<Array<Any>> {
+      return listOf(
+        arrayOf("1.5", true),
+        arrayOf("1.6", true),
+        arrayOf("1.6", false)
+      )
+    }
+  }
+
  @Rule @JvmField var temporaryFolder: TemporaryFolder = TemporaryFolder()

  @Test
@@ -455,8 +474,13 @@ class JsonClassCodegenProcessorTest {
          """
      )
    )
+    if (languageVersion == "1.5" || !instantiateAnnotations) {
      assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.COMPILATION_ERROR)
      assertThat(result.messages).contains("JsonQualifier @UpperCase must support FIELD target")
+    } else {
+      // We instantiate directly!
+      assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.OK)
+    }
  }

  @Test
@@ -665,7 +689,9 @@ class JsonClassCodegenProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.UsingQualifiers" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.UsingQualifiers" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.UsingQualifiers
              -keepnames class testPackage.UsingQualifiers
@@ -678,6 +704,19 @@ class JsonClassCodegenProcessorTest {
              -keep @interface testPackage.MyQualifier
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.UsingQualifiers
+              -keepnames class testPackage.UsingQualifiers
+              -if class testPackage.UsingQualifiers
+              -keep class testPackage.UsingQualifiersJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        "moshi-testPackage.MixedTypes" -> assertThat(generatedFile.readText()).contains(
          """
          -if class testPackage.MixedTypes
@@ -704,7 +743,9 @@ class JsonClassCodegenProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.Complex" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.Complex" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.Complex
              -keepnames class testPackage.Complex
@@ -723,6 +764,25 @@ class JsonClassCodegenProcessorTest {
              }
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.Complex
+              -keepnames class testPackage.Complex
+              -if class testPackage.Complex
+              -keep class testPackage.ComplexJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi,java.lang.reflect.Type[]);
+              }
+              -if class testPackage.Complex
+              -keepnames class kotlin.jvm.internal.DefaultConstructorMarker
+              -if class testPackage.Complex
+              -keepclassmembers class testPackage.Complex {
+                  public synthetic <init>(java.lang.String,java.util.List,java.lang.Object,int,kotlin.jvm.internal.DefaultConstructorMarker);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        "moshi-testPackage.MultipleMasks" -> assertThat(generatedFile.readText()).contains(
          """
          -if class testPackage.MultipleMasks
@@ -739,7 +799,9 @@ class JsonClassCodegenProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.NestedType.NestedSimple" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.NestedType.NestedSimple" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.NestedType${'$'}NestedSimple
              -keepnames class testPackage.NestedType${'$'}NestedSimple
@@ -752,6 +814,19 @@ class JsonClassCodegenProcessorTest {
              -keep @interface testPackage.NestedType${'$'}NestedQualifier
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.NestedType${'$'}NestedSimple
+              -keepnames class testPackage.NestedType${'$'}NestedSimple
+              -if class testPackage.NestedType${'$'}NestedSimple
+              -keep class testPackage.NestedType_NestedSimpleJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        else -> error("Unexpected proguard file! ${generatedFile.name}")
      }
    }
@@ -765,6 +840,8 @@ class JsonClassCodegenProcessorTest {
        inheritClassPath = true
        sources = sourceFiles.asList()
        verbose = false
+        kotlincArguments = listOf("-language-version", languageVersion)
+        kaptArgs[OPTION_INSTANTIATE_ANNOTATIONS] = "$instantiateAnnotations"
      }
  }

--- a/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorTest.kt
+++ b/kotlin/codegen/src/test/java/com/squareup/moshi/kotlin/codegen/ksp/JsonClassSymbolProcessorTest.kt
@@ -16,6 +16,7 @@
 package com.squareup.moshi.kotlin.codegen.ksp

 import com.google.common.truth.Truth.assertThat
+import com.squareup.moshi.kotlin.codegen.api.Options
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATED
 import com.squareup.moshi.kotlin.codegen.api.Options.OPTION_GENERATE_PROGUARD_RULES
 import com.tschuchort.compiletesting.KotlinCompilation
@@ -30,15 +31,41 @@ import org.junit.Ignore
 import org.junit.Rule
 import org.junit.Test
 import org.junit.rules.TemporaryFolder
-import kotlin.reflect.KClassifier
-import kotlin.reflect.KType
-import kotlin.reflect.KTypeProjection
-import kotlin.reflect.KVariance
-import kotlin.reflect.KVariance.INVARIANT
-import kotlin.reflect.full.createType
+import org.junit.runner.RunWith
+import org.junit.runners.Parameterized

 /** Execute kotlinc to confirm that either files are generated or errors are printed. */
-class JsonClassSymbolProcessorTest {
+@RunWith(Parameterized::class)
+class JsonClassSymbolProcessorTest(
+  private val languageVersion: String,
+  private val instantiateAnnotations: Boolean
+) {
+
+  companion object {
+    @JvmStatic
+    @Parameterized.Parameters(name = "languageVersion={0},instantiateAnnotations={1}")
+    fun data(): Collection<Array<Any>> {
+      // TODO KSP doesn't recognize language version yet https://github.com/google/ksp/issues/611
+      //  toe-holds for the future
+      val runtimeVersion = KotlinVersion.CURRENT
+      return mutableListOf<Array<Any>>().apply {
+        if (runtimeVersion.major != 1 || runtimeVersion.minor != 6) {
+          // True by default but still 1.5
+          // Can't test when running with 1.6 because lang version is still 1.6 per above comment
+          add(arrayOf("1.5", true))
+        }
+        // Redundant case, set to false but still 1.5
+        add(arrayOf("1.5", false))
+        if (runtimeVersion.major != 1 || runtimeVersion.minor != 5) {
+          // Happy case - 1.6 and true by default
+          // Can't test when running with 1.5 because lang version is still 1.5 per above comment
+          add(arrayOf("1.6", true))
+        }
+        // 1.6 but explicitly disabled
+        add(arrayOf("1.6", false))
+      }
+    }
+  }

  @Rule @JvmField var temporaryFolder: TemporaryFolder = TemporaryFolder()

@@ -490,8 +517,13 @@ class JsonClassSymbolProcessorTest {
          """
      )
    )
+    if (languageVersion == "1.5" || !instantiateAnnotations) {
      assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.COMPILATION_ERROR)
      assertThat(result.messages).contains("JsonQualifier @UpperCase must support FIELD target")
+    } else {
+      // We instantiate directly!
+      assertThat(result.exitCode).isEqualTo(KotlinCompilation.ExitCode.OK)
+    }
  }

  @Test
@@ -704,7 +736,9 @@ class JsonClassSymbolProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.UsingQualifiers" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.UsingQualifiers" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.UsingQualifiers
              -keepnames class testPackage.UsingQualifiers
@@ -717,6 +751,19 @@ class JsonClassSymbolProcessorTest {
              -keep @interface testPackage.MyQualifier
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.UsingQualifiers
+              -keepnames class testPackage.UsingQualifiers
+              -if class testPackage.UsingQualifiers
+              -keep class testPackage.UsingQualifiersJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        "moshi-testPackage.MixedTypes" -> assertThat(generatedFile.readText()).contains(
          """
          -if class testPackage.MixedTypes
@@ -743,7 +790,9 @@ class JsonClassSymbolProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.Complex" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.Complex" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.Complex
              -keepnames class testPackage.Complex
@@ -762,6 +811,25 @@ class JsonClassSymbolProcessorTest {
              }
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.Complex
+              -keepnames class testPackage.Complex
+              -if class testPackage.Complex
+              -keep class testPackage.ComplexJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi,java.lang.reflect.Type[]);
+              }
+              -if class testPackage.Complex
+              -keepnames class kotlin.jvm.internal.DefaultConstructorMarker
+              -if class testPackage.Complex
+              -keepclassmembers class testPackage.Complex {
+                  public synthetic <init>(java.lang.String,java.util.List,java.lang.Object,int,kotlin.jvm.internal.DefaultConstructorMarker);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        "moshi-testPackage.MultipleMasks" -> assertThat(generatedFile.readText()).contains(
          """
          -if class testPackage.MultipleMasks
@@ -778,7 +846,9 @@ class JsonClassSymbolProcessorTest {
          }
          """.trimIndent()
        )
-        "moshi-testPackage.NestedType.NestedSimple" -> assertThat(generatedFile.readText()).contains(
+        "moshi-testPackage.NestedType.NestedSimple" -> {
+          if (languageVersion == "1.5" || !instantiateAnnotations) {
+            assertThat(generatedFile.readText()).contains(
              """
              -if class testPackage.NestedType${'$'}NestedSimple
              -keepnames class testPackage.NestedType${'$'}NestedSimple
@@ -791,6 +861,19 @@ class JsonClassSymbolProcessorTest {
              -keep @interface testPackage.NestedType${'$'}NestedQualifier
              """.trimIndent()
            )
+          } else {
+            assertThat(generatedFile.readText()).contains(
+              """
+              -if class testPackage.NestedType${'$'}NestedSimple
+              -keepnames class testPackage.NestedType${'$'}NestedSimple
+              -if class testPackage.NestedType${'$'}NestedSimple
+              -keep class testPackage.NestedType_NestedSimpleJsonAdapter {
+                  public <init>(com.squareup.moshi.Moshi);
+              }
+              """.trimIndent()
+            )
+          }
+        }
        else -> error("Unexpected proguard file! ${generatedFile.name}")
      }
    }
@@ -805,20 +888,12 @@ class JsonClassSymbolProcessorTest {
        sources = sourceFiles.asList()
        verbose = false
        kspIncremental = true // The default now
+        kotlincArguments = listOf("-language-version", languageVersion)
+        kspArgs[Options.OPTION_INSTANTIATE_ANNOTATIONS] = "$instantiateAnnotations"
      }
  }

  private fun compile(vararg sourceFiles: SourceFile): KotlinCompilation.Result {
    return prepareCompilation(*sourceFiles).compile()
  }
-
-  private fun KClassifier.parameterizedBy(vararg types: KType): KType {
-    return createType(
-      types.map { it.asProjection() }
-    )
-  }
-
-  private fun KType.asProjection(variance: KVariance? = INVARIANT): KTypeProjection {
-    return KTypeProjection(variance, this)
-  }
 }
--- a/kotlin/tests/build.gradle.kts
+++ b/kotlin/tests/build.gradle.kts
@@ -19,7 +19,7 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 plugins {
  kotlin("jvm")
  kotlin("kapt") apply false
-  alias(libs.plugins.ksp) apply false
+  id("com.google.devtools.ksp") apply false
 }

 val useKsp = hasProperty("useKsp")
@@ -34,11 +34,14 @@ tasks.withType<Test>().configureEach {
  jvmArgs("--add-opens=java.base/java.io=ALL-UNNAMED")
 }

+val useWError = findProperty("kotlinLanguageVersion")?.toString()
+  ?.startsWith("1.5")
+  ?: false
 tasks.withType<KotlinCompile>().configureEach {
  kotlinOptions {
+    allWarningsAsErrors = useWError
    @Suppress("SuspiciousCollectionReassignment")
    freeCompilerArgs += listOf(
-      "-Werror",
      "-Xopt-in=kotlin.ExperimentalStdlibApi"
    )
  }