Kotlin 2.1.0-Beta2

Changelog

Analysis API. Caches and Invalidation

• KT-71700 Cache result of resolveToCall
• KT-71520 Analysis API: LLFirNativeForwardDeclarationsSymbolProvider spends a lot of time in indices

Analysis API. Lazy Resolution

• KT-71567 LLFirCompilerRequiredAnnotationsTargetResolver should calculate annotation arguments on demand
• KT-71584 getNonLocalContainingOrThisDeclaration treats KtParameter from functional type as non-local
• KT-71566 FirElementBuilder#getFirForNonKtFileElement should iterate a Psi file over and over
• KT-71224 Analysis API: FirElementFinder.collectDesignationPath relies on naive iteration through FIR files

Analysis API. Light Classes

• KT-71693 Wrong name mangling for JvmField class property and companion property clash
• KT-71469 KtLightClassForDecompiledDeclaration: missed kotlinOrigin

Analysis API. Stubs and Decompilation

• KT-71565 KtClassOrObject should use isLocal from greenStub

Analysis API. Surface

• KT-71731 directlyOverridenSymbols/allOverridenSymbols works incorrectly for intersection overrides

Analysis. API

Performance Improvements

• KT-70165 Introduce PSI-based KaSymbols for K2

Fixes

• KT-64984 Analysis API: Support Wasm target
• KT-70375 K2: NPE at org.jetbrains.kotlin.analysis.api.fir.symbols.KaFirNamedClassSymbolBase.createPointer
• KT-57733 Analysis API: Use optimized ModuleWithDependenciesScopes in combined symbol providers
• KT-70437 Class reference is not resolvable
• KT-70327 Analysis API: Batch inspection causes deadlock in ValueWithPostCompute
• KT-71259 K2 evaluator: Invalid smart cast info collecting for Code Fragments
• KT-65110 Analysis API: In Standalone mode the order of symbols is unstable
• KT-71468 Drop redundant logic from LLFirJavaFacadeForBinaries
• KT-70890 Analysis API: Experiment with weak references to LL FIR/analysis sessions in session caches
• KT-70474 FirLazyResolveContractViolationException from JavaSymbolProvider
• KT-70657 Analysis API: Inner types from classes with generics are incorrectly represented by the compiled jars
• KT-71055 Suspend calls inside 'analyze()' break the block guarantees
• KT-70815 Analysis API: Implement stop-the-world session invalidation
• KT-69819 K2 IDE: LHS type in callable references is unresolved when it has type arguments and is qualified
• KT-68761 Analysis API: Experiment with limited-size cache in KaFirSessionProvider
• KT-70384 Analysis API Standalone: The same class in the same two renamed jars is unresolved
• KT-71067 Exceptions from references cancel Find Usages
• KT-69190 K2: False-positive "redundant private modifier"
• KT-63390 K2: Analysis API: add annotations to KtClassInitializerSymbol
• KT-71025 K2 IDE: Scopes in "importingScopeContext" have reversed ordering and "indexInTower" values

Apple Ecosystem

• KT-69093 Xcode 16 support in Kotlin
• KT-66894 XCFramework task fails when name passed to xcframework DSL is different from framework's name
• KT-65675 XCFrameworkTask produces an xcframework with mismatched casing in embedded frameworks

Backend. Native. Debug

• KT-71374 lldb: step out breaks breaking in Xcode 16

Backend. Wasm

• KT-72156 custom-formatters.js exists in JAR after publishToMavenLocal but not in the published artifact in Maven public
• KT-70331 Support incremental compilation for the Wasm backend
• KT-71686 K/Wasm: Add functions to convert between Kotlin and JS array types
• KT-71473 K/Wasm: Use --closed-world and related options for Binaryen
• KT-71800 Wasm compiler: Fix member generation for data classes with an array-type property
• KT-71580 String::toFloat on wasm behaves differently compared to other targets
• KT-71523 K/Wasm: cleanup after fix for KT-71474
• KT-71475 K/Wasm: KClass::qualifiedName returns incorrect result for nested or companion objects
• KT-71474 K/Wasm: KProperty*Impl equals work incorrectly for clabbale reference created in different files or modules
• KT-71294 Wasm Artifacts/Resource are being loaded relatively instead of absolutely

Compiler

New Features

• KT-71094 Kotlin/Native incremental compilation: fail compilation if cache build failed
• KT-70679 Kotlin/Native: fill WritableTypeInfo from Swift Export type mapping
• KT-54227 Cannot use nullable Nothing as reified type parameter
• KT-71430 Kotlin-to-Java direct actualization implementation
• KT-68163 Expose supplementary compiler warnings via CLI

Performance Improvements

• KT-71159 [K2] OOM on large enum classes with fields

Fixes

• KT-71480 JAVA_CLASS_INHERITS_KT_PRIVATE_CLASS isn't reported while java object isn't created
• KT-71508 JAVA_CLASS_INHERITS_KT_PRIVATE_CLASS isn't reported when java class is inherited from an effectively private class
• KT-71260 K2: Internal compiler error in IrFakeOverrideSymbolBase.getOwner when there is no actual for expect
• KT-58820 OPT_IN_USAGE_ERROR's message text does not account for SubclassOptInRequired
• KT-71034 Failing compiler/testData/codegen/box/inlineClasses/kt70461.kt
• KT-71016 K/Wasm: Failing compiler/testData/codegen/box/inlineClasses/kt70461.kt
• KT-60521 Drop language versions 1.4 and 1.5
• KT-72154 Dokka fails with not array: KClass<out Annotation> on Kotlin 2.1.20-dev with @SubclassOptInRequired
• KT-70562 @SubclassOptInRequired cannot accept multiple experimental marker
• KT-71708 False negative UNSUPPORTED for collection literals as trailing return value
• KT-52469 Deprecate reified type parameter instantiating into intersection types
• KT-71563 'llegalStateException: Source classes should be created separately before referencing' when actualized through typealias and java direct actualization
• KT-71756 K2 evaluator: broken resolve of private members during debug of Kotlin project itself
• KT-71550 JVM IR: NPE on identity equals of boolean true with null
• KT-71490 K2: missing REDUNDANT_ELSE_IN_WHEN
• KT-64403 Implement BlackBoxCodegenTestSpecGenerated for K2
• KT-71551 JVM IR K1: NPE on generating a function imported from an object from another module
• KT-71210 K2: false negative FUNCTION_CALL_EXPECTED / NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE with companion objects
• KT-69549 Try to move callable reference transformation earlier in pipeline
• KT-71228 K2: "IllegalArgumentException: Failed requirement" caused by lambda parameter and class type
• KT-71738 K2: False negative REDECLARATION inside object expression
• KT-70407 Error/warning message for @SubclassOptInRequired-annotated class should provide more context
• KT-71701 K2: false positive CAN_BE_VAL with lateinit and non-in-place lambda
• KT-68694 K2 IDE / Kotlin Debugger: AE “Unresolved reference: <HIDDEN: samples/gen/classes/enum class/EnumClass.lam is invisible” on evaluating private lambda inside enum entry
• KT-70970 K2 IDE / Kotlin Debugger: AE “Only assignable IrValues can be set” on calling overloaded inc() operator on interface
• KT-70824 K2: NoSuchFieldException when evaluating private extension property
• KT-70390 K2 IDE / Kotlin Debugger: can't invoke lambda from private class during evaluation
• KT-68701 K2 IDE / Kotlin Debugger: AE “ERROR_CALL 'Unresolved reference: <HIDDEN: /privateLambda is invisible>#' type=IrErrorType(null)” on evaluating private top-level lambda
• KT-68695 K2 IDE / Kotlin Debugger: AE “Unsupported callable reference” on evaluating ::lateinitStr on private lateinit property
• KT-70861 K2 IDE / Kotlin Debugger: can't evaluate Clazz::class call for private class
• KT-34911 Improve error message for WRONG_ANNOTATION_TARGET: list applicable targets
• KT-8322 Prohibit use of Nothing as catch parameter
• KT-71601 K2: When with a subject of type dynamic always considered exhaustive
• KT-33091 Kotlin/Native: Compiler crashes if an external class is declared
• KT-59651 K1/K2: Assertion error on external enum usage attempt
• KT-71121 Kotlin/JS incremental compilation fails with KotlinIllegalArgumentExceptionWithAttachments
• KT-69939 Extract a category of internal FIR checkers from supplementary FIR checkers
• KT-71122 Regression in Kotlin Compiler 2.0 causing NPE in the runtime
• KT-71117 K2: "IllegalArgumentException: No type for StarProjection" with star projection and function type
• KT-71251 Native & JS K2: Missing check for calling isInitialized inside inline fun
• KT-71215 K2: UB due to the erroneous greening of the red code with multiple delegation with java
• KT-59386 K2: Missing CONSTANT_EXPECTED_TYPE_MISMATCH
• KT-69040 PCLA: deal with "deep" calls that can be fully analyzed properly
• KT-71046 K/N: a separate lowering to convert function reference to IrConstantObject
• KT-70931 K2 / Scripts: "cannot convert IrExpression to ConstantValue" when using function annotation
• KT-69223 Drop parallel lowering mode in JVM backend
• KT-70260 @JsPlainObject: improve compiler error if a method is present
• KT-67739 Improve error message when JDK used in -Xjdk-release has corrupted class files
• KT-63964 K2: different naming of classes defined in script in metadata
• KT-70014 Common inference: introduce rigidTypeMarker
• KT-71352 Cannot load script definition class org.gradle.kotlin.dsl.KotlinProjectScriptTemplate
• KT-63502 Getting java.lang.ClassNotFoundException: javaslang.λ during compilation
• KT-66316 Kotlin/Native: make @Escapes annotation required for all external functions
• KT-70965 FIR/AA: Initializers for Java annotation arguments mapping capture use-site sessions
• KT-64453 K2: Implement ComposeLikeIr...TestGenerated for K2
• KT-30424 Confusing error message "modality is different"
• KT-70846 Replace ConeKotlinType.nullability with isMarkedNullable on specific types
• KT-56720 K2: false positive MANY_IMPL_MEMBER_NOT_IMPLEMENTED in case of delegation in diamond inheritance
• KT-69937 Define & enforce user-friendly terminology for extended checkers
• KT-64406 K2: Implement CompileKotlinAgainstJavaTestGenerated for K2
• KT-69938 Validate sets of default compiler warnings and supplementary compiler warnings
• KT-68971 Investigate suspicious fragmentation of FIR trees for string literals with interpolation
• KT-71213 Rethrow exceptions in checkers with some useful attachments
• KT-71189 K2: emit 'DELEGATE_SPECIAL_FUNCTION_MISSING' and 'DELEGATE_SPECIAL_FUNCTION_NONE_APPLICABLE' on 'by' keyword
• KT-71178 K2: False negative NO_ELSE_IN_WHEN in when over nullable type with !is Nothing? check
• KT-70812 False positive NO_ELSE_IN_WHEN with nullable type argument as subject
• KT-70947 False positive NO_ELSE_IN_WHEN with DNN subject and nullable sealed class upper bound
• KT-67383 Incorrect optimisation when optimising for loop with UByte
• KT-70752 Review diagnostics with whole declaration as range
• KT-71160 K2: Rendering of flexible collection types and arrays is too verbose
• KT-61227 Definitely non-nullable types cause "Any was expected" for @Nullable parameter
• KT-69389 K2: NONE_APPLICABLE instead of more useful "type mismatch" error with overloads and parameter nullability mismatch
• KT-70930 K2: Java annotations not present on ENUM_ENTRY IR elements
• KT-69794 K2: Wrong target is reported for EXPOSED_SUPER_INTERFACE diagnostic
• KT-70724 False-positive UNINITIALIZED_VARIABLE for inline constructor with late-initialized variables
• KT-70749 False-positive UNINITIALIZED_VARIABLE for inline fun with crossinline modifier

Compose compiler

New features

• b/328817808 Added the PausableComposition feature flags

Fixes

• b/366040842, b/365066530 Replace deep copy in Compose plugin with in-place type mutation
• b/329477544 Force open / overridden Composable functions to be non-restartable.
• b/361652128 Disable live literal transform if the corresponding flag is disabled

IR. Actualizer

• KT-71631 Kotlin-to-Java direct actualization: java annotation element isn't actualized
• KT-71597 Kotlin-to-Java direct actualization: it is possible to actualize a function with default parameters
• KT-71592 Kotlin-to-Java direct actualization: constructor of nested class can't be actualized
• KT-71577 Kotlin-to-Java direct actualization: method can be actualized by java static method
• KT-71817 Actualization of static members is broken for non-JVM platforms

IR. Inlining

Fixes

• KT-69565 Don't generate synthetic accessors for private symbols inside local classes
• KT-71137 Generate synthetic accessors for backing fields
• KT-64865 Explicitly generate accessors for private declarations in inline functions
• KT-70420 Enable double-inlining in Native & JS backends by default
• KT-71657 K/JS: Double-inlining causes failures in IC with top-level synthetic accessors
• KT-71659 IR Inliner fails to inline function expressions due to implicit cast from the 1st phase of inlining
• KT-71078 Inline all functions in local classes at the 1st stage of inlining
• KT-66508 IR inliner: Add implicit cast for initializer of temporary variables
• KT-66507 IR inliner: Enable implicit casts in all KLib backends
• KT-69466 IrInlinedFunctionBlock: Refactor it to make it possible to serialize in KLIBs
• KT-69317 IR Inlining. Try to place inlined arguments outside IrInlinedFunctionBlock
• KT-69307 Source offsets seem incorrect after IR inlining
• KT-67149 Common Native/JS lowering prefix at the 2nd phase of compilation
• KT-69681 IR: Report warnings on exposure of private types in non-private inline functions
• KT-71232 Implement an IR validation check that ensures that all IrFields are private on non-JVM backends
• KT-67304 Keep in common prefix: Shared variables + local classes in inline lambdas
• KT-70583 Internal error in body lowering: java.lang.IllegalStateException: An attempt to generate an accessor after all accessors have been already added to their containers

IR. Tree

• KT-71826 stdlib fails to compile with -Xserialize-ir=all
• KT-67752 Make copyRemappedTypeArgumentsFrom and transformValueArguments methods in DeepCopyIrTreeWithSymbols protected instead of private
• KT-69644 Report warning on cross-file IrGetField operations generated by compiler plugins
• KT-71191 SymbolTable: Check if the provided signature is public before adding a symbol to the SymbolTable

JavaScript

Fixes

• KT-70117 Generate debug info for code from js call
• KT-69408 [JS] Enable insertAdditionalImplicitCasts=true (as in other KLIB-based backends)
• KT-67452 K2: Consider hiding dynamic type creation under FlexibleTypeFactory for JS only
• KT-70226 Delete JS tests that were only run with the legacy JS backend
• KT-71338 K/JS: Add a flag for switching generating arrow functions on & off
• KT-70707 KJS: asJsReadonlyMapView does not implement ReadonlyMap correctly
• KT-71220 Fix invalid IrFunctionReference creation in InnerClassConstructorCallsLowering
• KT-70229 Remove test classes related to the legacy JS backend
• KT-70359 Remove legacy backend-related test directives from Kotlin/JS tests
• KT-70362 Clean up Gradle tasks for running JS tests against the legacy JS backend
• KT-30016 JS BE does not generate special bridge methods

Klibs

• KT-64169 [KLIB Resolve] Don't skip libraries that happen to have the same unique_name
• KT-67448 [KLIB Resolve] Deprecate passing KLIB unique names via CLI
• KT-71455 [KLIB Resolve] Forbid passing KLIB unique names via CLI
• KT-67474 K2: Missing @ExtensionFunctionType in metadata in KLIBs
• KT-67450 [KLIB Resolve] Kotlin/Native: Only one implicit repository should remain for the compiler ("dist")
• KT-61098 [KLIB Resolve] Don't allow working with KLIB "repositories"
• KT-66218 Clean-up the code for serialization & deserialization of DFGs to & from KLIBs

Language Design

• KT-71222 Remove @ExperimentalSubclassOptIn from SubclassOptInRequired
• KT-67675 Allow usage of Array<Nothing?>
• KT-69924 Mention 'if' guard when '&&' is used incorrectly

Libraries

Performance Improvements

• KT-66715 Performance: faster alternative to String.lines()

Fixes

• KT-71628 Review deprecations in stdlib for 2.1
• KT-71660 Stabilize experimental API for 2.1
• KT-54299 Extract org.w3c declarations to separate library from K/Wasm Stdlib
• KT-68027 Document caveats and deincentivise usage of measureTimeMillis
• KT-71581 Update outdated documentation to common lazy and provide samples
• KT-71796 Improve documentation for Path.walk and Path.visitFileTree functions
• KT-69545 Kotlin/Native: Deprecate API marked with FreezingIsDeprecated to error
• KT-38754 Deprecate appendln in favor of appendLine
• KT-68019 Fill in missing package descriptions for standard library documentation
• KT-52181 Native: Inconsistent behaviour of LinkedHashMap#entries on JVM and Native
• KT-71570 Document suspend lambda builder
• KT-46785 Get rid of !! after readLine() in the standard library

Native

• KT-71435 Native: cannot access class 'objcnames.classes.Protocol'

Native. Build Infrastructure

• KT-71820 Update the coroutines version used in kotlin-native build infrastructure

Native. Platform Libraries

• KT-70032 Rebuild platform libraries in 2.1.0 with Xcode 16
• KT-71624 Eliminate remaining UIKit/AppKit removed signatures
• KT-70031 Rebuild platform libraries in 2.0.21 with Xcode 16

Native. Runtime

• KT-70680 Kotlin/Native: Use WritableTypeInfo when creating Swift wrapper from the runtime
• KT-70568 Native: revert workaround for debug with LLVM 16

Native. Runtime. Memory

• KT-70364 Kotlin/Native: data race during GC initialization

Native. Swift Export

• KT-71539 Swift Export: export class member overrides
• KT-70678 Swift Export: generate Kotlin<->Swift type mapping
• KT-70920 Swift Export Nullability: primitive type
• KT-71087 Swift Export: Nullability: Never
• KT-71086 Swift Export: Nullability: Strings
• KT-70919 Swift Export Nullability: reference type
• KT-71026 Swift Export: function overloading with ref types does not work
• KT-70960 Swift Export nullability: add nullability to sir and printer

Reflection

• KT-71378 KotlinReflectionInternalError: Inconsistent number of parameters in the descriptor and Java reflection object

Tools. CLI

• KT-70179 K2: Building a file with kotlin-test-junit without junit does not include annotations
• KT-71537 Add JVM target bytecode version 23
• KT-61745 K2: support light tree in multi-module chunk mode
• KT-70885 Errors are not reported for wrong arguments in -Xsuppress-warning flag for non-jvm backends
• KT-70991 K2: Compilation fails if project version has a comma

Tools. CLI. Native

• KT-68673 Kotlin/Native "You have not specified any compilation arguments. No output has been produced" when no source nor -Xinclude is passed

Tools. Compiler Plugins

• KT-71658 Transform top-level atomic properties to Java boxed atomics
• KT-65645 Atomicfu-plugin: compilation hangs on a long string concatenation
• KT-69038 Power-Assert does not display const vals
• KT-71525 Setting JvmAbiConfigurationKeys.REMOVE_PRIVATE_CLASSES = true triggers java.util.ConcurrentModificationException
• KT-41888 IrExpression startOffset and endOffset are inconsistent with raw file text
• KT-69856 Compose Plugin: IrType.erasedUpperBound throws NullPointerException when evaluating IrScript nodes due to missing targetClass
• KT-69410 PowerAssert: Cannot find overload of requireNotNull without existing message
• KT-66293 Atomicfu-plugin: wrong return types for lowered extension functions
• KT-71038 PowerAssert: Constant on RHS of elvis operator leads to compiler crash

Tools. Daemon

• KT-69929 compileKotlin task reports that daemon has terminated unexpectedly

Tools. Fleet. ObjC Export

• KT-71162 ObjCExport: nullable functional type with reference arguments
• KT-71022 ObjCExport: enum c keywords translation
• KT-71082 ObjCExport: KotlinUnit translated as Function1
• KT-70781 ObjCExport: classifiers and callables type parameters translation
• KT-70943 ObjCExport: extension order
• KT-70840 ObjCExport: duplicated interfaces

Tools. Gradle

New Features

• KT-71602 Introduce KotlinTopLevelExtension
• KT-71603 Introduce KotlinJvmExtension and KotlinAndroidExtension
• KT-70383 KotlinJvmFactory registerKaptGenerateStubsTask() function should also request compilation task provider
• KT-69927 Need ability to pass KotlinJvmCompilerOptions to registerKotlinJvmCompileTask()
• KT-69940 Expose supplementary compiler warnings via KGP
• KT-71227 [Compose] Add PausableComposition feature flag to the Compose Gradle Plugin

Performance Improvements

• KT-65285 Use uncompressed Klibs

Fixes

• KT-69851 Compatibility with Gradle 8.10 release
• KT-58956 Offer a shared interface for JVM and Android compilerOptions in Project extension
• KT-71405 Compose compiler gradle plugin: project.layout.file can't be used as a value of the 'stabilityConfigurationFiles' option
• KT-65565 Remove deprecated common platform plugin id
• KT-70430 Clean-up obsolete Gradle plugin variants for Gradle versions <7.6
• KT-69853 Compile against Gradle API 8.10
• KT-69852 Run Gradle integration tests against Gradle 8.10 release
• KT-71411 Add FUS statistics for new Dokka tasks
• KT-71291 Log plugins from the list as Gradle plugins
• KT-66049 KGP JVM: Publishing isn't compatible with isolated projects and project dependencies
• KT-65990 Update GradleDeprecatedOption.level values for arguments removed from the DSL after 2.1

Tools. Gradle. JS

• KT-69628 K/Wasm: Node.js version per project
• KT-71536 [JS, Wasm] Stop collecting information about KLIB IC in Kotlin2JsCompile

Tools. Gradle. Multiplatform

New Features

• KT-70897 Add KotlinBaseApiPlugin.kotlinAndroidExtension

Fixes

• KT-72068 Distribution for klib cross-compilation is not downloaded during compile tasks
• KT-69412 Change KotlinTargetAlreadyDeclaredChecker's severity from warning to error
• KT-66461 Promote compiler options DSL for multiplatform projects to stable
• KT-71529 Deprecate targetFromPreset API with an error
• KT-71423 Xcode archive missing dSYM files since Kotlin 2.0.20
• KT-71209 Drop Hierarchy Template diagnostic about used shortcuts
• KT-71675 checkSandboxAndWriteProtection collides with Compose's syncComposeResources
• KT-71428 Change deprecation message for KMP target shorcuts
• KT-71444 Certain POMs produced by Kotlin 2.0.20 cannot be consumed by KMP projects with Android targets
• KT-69974 KMP: POM dependency rewriter doesn't work with Included Builds OR dependencySubstitution
• KT-58231 Kotlin Gradle Plugin: set deprecation level to Error for KotlinTarget.useDisambiguationClassifierAsSourceSetNamePrefix and overrideDisambiguationClassifierOnIdeImport
• KT-71206 KGP: Test source set may get duplicated KLIBs of different versions

Tools. Gradle. Native

• KT-71398 kotlinNativeBundleConfiguration should not contain dependencies on unsupported platforms
• KT-45559 CInteropProcess: Changes to header files are not recognized; Task is still UP-TO-DATE
• KT-71722 kotlinNativeBundleConfiguration present in JVM-only Gradle project

Tools. JPS

• KT-71450 Constant build failure: com.intellij.util.io.ClosedStorageException: storage is already closed

Tools. Kapt

• KT-71431 K2KAPT fails on modules without any annotation processors

Tools. REPL

• KT-71109 Kotlin Scripting REPL doesn't support keyboard shortcuts

Tools. Scripts

• KT-68685 K2 / Script: "KotlinReflectionInternalError: Unresolved class:" caused by main.kts script with nested classes and reflection

Tools. Wasm

• KT-71506 [Wasm, IC] FUS report for builds with incremental compilation
• KT-70367 Update binaryen once we get a release with PR 6793
• KT-67863 K/Wasm: Remove ChromeWasmGc
• KT-71360 K/JS & K/Wasm: Upgrade NPM dependencies