Changelog

Analysis API

• KT-80082 K2. False positive "Cannot resolve method" for self-bounded generic with wildcard return type in Java interop
• KT-80303 Move:native:analysis-api-klib-reader to:libraries:tools

Analysis API. Code Compilation

• KT-70860 K2 IDE / Kotlin Debugger: CCE “java.lang.String cannot be cast to java.lang.Void” on evaluating not-null variable on the line with assigning null to that var
• KT-78554 K2 IDE / Kotlin Debugger: ISE “No override for FUN IR_EXTERNAL_DECLARATION_STUB” on calling toString() for local class instance during evaluation
• KT-73201 K2 IDE: Error while evaluating expressions with local classes

Analysis API. FIR

• KT-81378 Expected expression 'FirFunctionCallImpl' to be resolved caused bysuspend {}
• KT-80473 Add events for tracking LL activities
• KT-46375 Analysis API: Support cross-file class redeclaration checks using indices
• KT-80471 Analysis API: Deduplicate equivalent call candidates inresolveToCallCandidates
• KT-79653 [Analysis API] ContextCollector: BODY context of enum classes doesn't contain enum entries
• KT-75858 K2 AA: False positive 'property must be initialized' on incremental analysis with 'field' usage and semicolon in setter
• KT-80231 AnnotationArgumentsStateKeepers doesn't restore the initial annotation in some cases
• KT-80233 Pull mutation out of AnnotationArgumentsStateKeepers
• KT-71466LLFirBuiltinsSessionFactory usescreateCompositeSymbolProvider
• KT-76432 JavaClassUseSiteMemberScope: Expected FirResolvedTypeRef with ConeKotlinType but was FirUserTypeRefImpl

Analysis API. Infrastructure

• KT-80717 Support IntelliJ Bazel build in the Kotlin Coop development mode

Analysis API. Light Classes

• KT-80656 Duplicate no-args constructor in PSI
• KT-60490 Symbol Light Classes: Property accessors from a delegated interface don't present in the delegating class
• KT-79689 SymbolLightClassForClassLike.toString() causes PSI tree loading
• KT-80690 Private interface functions are not present in light classes
• KT-80256 K2: Certain actions in JPA code causes infinite PIEAE: "Element class CompositeElement of type REFERENCE_EXPRESSION (class KtNameReferenceExpressionElementType)"
• KT-79012 Add a high-level overview of light classes

Analysis API. Providers and Caches

Fixes

• KT-81476 Analysis API:AlreadyDisposedException from low-memory cache cleanup
• KT-80911 Analysis API: Execute session invalidation in a non-cancelable section
• KT-81242 Analysis API: Add UUID/lifetime properties to LL FIR session structure logging
• KT-80622 Analysis API: Visualise LL FIR session structure & weight
• KT-80904 Analysis API: "Invalid dangling file module" exception during session invalidation
• KT-78882 K2 AA: Calling containingSymbol on getProgressionLastElement causes exception
• KT-58325 Analysis API: CombineLLKotlinStubBasedLibrarySymbolProviders in session dependencies (optimization)
• KT-77825 Analysis API:CheckersComponent consumes a lot of memory while being unused in LL FIR sessions
• KT-76526 Incorrect built-in module is provided for non-JVM sources in Standalone
• KT-62549 Analysis API: Cache callables in combined Kotlin symbol providers
• KT-70721 LL FIR: investigate possibility of movingLLFirFirClassByPsiClassProvider . getClassByPsiClass (PsiClass) to symbol providers
• KT-72998 Analysis API: IntroducegetClassLikeSymbolByPsi to LL FIR symbol providers

Analysis API. Standalone

• KT-81108 AA: java.lang.ClassCastException: class org.jetbrains.kotlin.fir.FirBinaryDependenciesModuleData cannot be cast to class org.jetbrains.kotlin.analysis.low.level.api.fir.projectStructure.LLFirModuleData
• KT-80573 Potential performance issue on class ID computation
• KT-80559 Try to optimize KotlinStandaloneDeclarationProviderFactory startup for tests
• KT-71706 Analysis API Standalone:StandaloneProjectFactory.createSearchScopeByLibraryRoots creates inefficient file-based search scopes

Analysis API. Stubs and Decompilation

Performance Improvements

• KT-77097 SupportReplaceWith deprecation annotation argument via stubs

Fixes

• KT-80350 Drop K1 decompiler
• KT-77082 StackOverflowError in CreateFreshTypeVariableSubstitutorStage.shouldBeFlexible
• KT-80798 Improve stubs tests coverage
• KT-75318 Read context parameter fields from metadata in CallableClsStubBuilder
• KT-77874 AA disagrees with the compiler on descriptions of context parameters from binaries in messages for context argument ambiguity errors
• KT-80276 Implement native coping for stubs
• KT-79780 Decompiled MultifileClass has Facade kind
• KT-79398 isClsStubCompiledToJvmDefaultImplementation flag is inconsistent for compiled and decompiled stubs
• KT-79798 Prettify stub usages in LL stub-based deserializer
• KT-78949 AbstractLLStubBasedResolutionTest: tests against real stub-based files
• KT-80251 Inconsistent decompiled and compiled stub for properties with an initializer and a delegate
• KT-74547 Implement decompiler for K2
• KT-79555 Move KotlinFileStubImpl serialization/deserialization to the Analysis API
• KT-79487 "null DefinitelyNotNullType for 'T'" from decompiler
• KT-60764 Stub Builder: fix differences between K1 and K2 stub building on decompiled files
• KT-79484 An empty enum class with a member decompiles with a synthetic error
• KT-79730 Decompiled files have an extraKt suffix
• KT-79483 data modifier is not present on object modifier
• KT-75398 Local classes from scripts have ClassId in stubs
• KT-79412 Context parameters with type annotations cause inconsistency errors while building stubs

Analysis API. Surface

New Features

• KT-80084 Provide endpoints for Analysis API to understand when the context sensitive resolution is used
• KT-64340 Analysis API: no way to get a type of vararg parameter
• KT-68387 AA: provide context for type approximations

Performance Improvements

• KT-80713 Optimize KaDeclarationSymbol#visibility for class-like symbols
• KT-79097 KaFirNamedFunctionSymbol#isSuspend shouldn't trigger resolution
• KT-79095 isOverride shouldn't trigger resolution if not compiler plugins present

Fixes

• KT-80234 Incorrect value ofisActual for the implicitlyactual constructor of annotation class
• KT-81132 Use KaSession instead of a particular KaSessionComponent for context parameter bridges
• KT-81129 K2: KaSymbolInformationProvider#importableFqName: should return null for dynamic declarations
• KT-81128 K2: KaSymbolInformationProvider#importableFqName: should return null for error destructuring declarations
• KT-81127 K2: KaSymbolInformationProvider#importableFqName: should return null for anonymous functions
• KT-81126 K2: KaSymbolInformationProvider#importableFqName: should return null for enum entry initializer constructors
• KT-81125 K2: KaSymbolInformationProvider#importableFqName: should return null for property accessors
• KT-81124 K2: KaSymbolInformationProvider#importableFqName: type alias constructor should have a reference to the type alias and not to the underlying class
• KT-70127 Analysis API: 'KaFirReceiverParameterSymbol' does not implement 'KaFirSymbol'; leads to exception fromimportableFqName
• KT-81123 Reimplement KaFirSymbolInformationProvider#importableFqName
• KT-81122 Drop KaImportOptimizer
• KT-78093 Add bridges for context parameters
• KT-79772 Migrate from 'validityAsserted' to 'withValidityAssertion'
• KT-79328 K2 AA, isUsedAsExpression: Unhandled Non-KtExpression parent of KtExpression: class org.jetbrains.kotlin.psi.KtImportDirective
• KT-80366 IllegalStateException from KaFirStopWorldCacheCleaner
• KT-80274 Merge AbstractMultiModuleSymbolByPsiTest to AbstractSymbolByPsiTest
• KT-80352 KaBaseResolutionScope.contains(PsiElement) always returns false for Android light classes (e.g. synthetic R.java classes)
• KT-80178 Incorrect modality for an abstract interface function with a redundantopen modifier
• KT-79129 [Analysis API]KaFe10TypeCreator.buildClassType cannot build builtin types by class ids
• KT-79143 AA:argumentMapping contains an expression that is not an argument
• KT-59857 KaExpressionTypeProvider#returnType shouldn't throw an exception for class like declarations
• KT-79667 Enable resolve on java record components in standalone mode
• KT-73050KaFirSymbolRelationProvider#expectsForActual: suspicius logic for KaReceiverParameterSymbol
• KT-78904 KaBaseWriteActionStartedChecker throws when no additional WA was done
• KT-79281 Add KDoc toKaTypePointer#restore
• KT-78597 KaUseSiteVisibilityChecker returns false for internal functions exposed via implicit receiver
• KT-71705 FIR api impl: Postfix increment expression'sexpressionType is Unit when incrementing array element
• KT-75057 Analysis API: Reference to object through typealias in invoke operator call leads to original type

Backend. Native. Debug

• KT-79848 Flaky debugger tests in opt.debug/cache.*/GC.CMS/GC.sch.ad/alloc.custom configuration

Backend. Wasm

New Features

• KT-59032 Support instantiation of annotation classes on WASM

Fixes

• KT-76204 K/Wasm: support generating a wasm module per kotlin module/klib
• KT-79357 K/Wasm: store data for string literals in utf8 for Latin1
• KT-82075 K/Wasm: kotlin.wasm.internal.getSimpleName crashes on iOS Safari older than 26
• KT-79244 [Wasm] Drop K1-specific tests, testrunners and test directives
• KT-69621 K/Wasm: Consider enabling support for KClass.qualifiedName by default
• KT-80397 K/Wasm: turn on by default using a new version of the exception handling proposal for wasm-wasi target
• KT-81372 K/Wasm: JsException: Exception was thrown while running JavaScript code on Safari 18.2/18.3
• KT-80018 K/Wasm: exceptions don't work properly in JavaScriptCore (vm inside Safari, WebKit)
• KT-66072 K/Wasm: improve how exceptions work in JS interop
• KT-80106 devServer in Kotlin/Wasm overwrites defaults, causing missing static paths
• KT-80210 Wasm: "Unexpected non-external class: kotlin.Nothing" caused by JsExport with JsPromise
• KT-80555 WASM IC: Can't link symbol on kotlinx.coroutines on fresh master
• KT-80415 WasmJs Number Elvis Operator Crash
• KT-76509 WasmJS: ReferenceError: Temporal is not defined caused by "Redundant reference to unused external results"
• KT-79317 [Wasm] Do not throw CCE for ExcludedFromCodegen declarations
• KT-78036 K/Wasm: generate a message with "expected" and "actual" types in case of CCE

Compiler

New Features

• KT-80461 K2: false positive NO_ELSE_IN_WHEN for complex sealed hierarchy
• KT-77676 K/N: enable typechecks and the casts optimization pass in debug mode by default
• KT-79185 Support local type aliases
• KT-80837 Warn about extension function with a context shadowed by member
• KT-80768 Warning on overloading by a superset of context parameters in class context
• KT-80031 Check spotbugs's@CheckReturnValue in Kotlin's unused return value checker
• KT-79380 Native: add performance measurement for the rest of backend phases
• KT-79381 Native: add performance measurement of LLVM phases
• KT-80222 Implement the prohibition of always-falseis checks for definitely incompatible types
• KT-79295 Parse and build raw FIR from new short and full forms of positional destructuring with square brackets
• KT-74810 Support typealiased/mapped Java types in unused return value checker
• KT-71244 Incorporate existing@CheckReturnValue annotation(s) into Kotlin's unused return value checker
• KT-79922 Record 'MustUse/ExplicitlyIgnorable' state for overrides even in disabled RVC mode
• KT-79920 Store 'Explicitly ignorable' state of function/property in the metadata
• KT-79690 Implement a USELESS_ELVIS_LEFT_IS_NULL with elvis expression
• KT-79296 Implement/adapt diagnostics for new destructuring
• KT-79298 Report errors on new destructuring syntax in K1

Performance Improvements

• KT-81617 Native: casts optimizations pass explodes on deep nested loops
• KT-80554 Kotlin/Native: investigate performance hit from always-on llvm pass profiling
• KT-81340 K/N: severe compilation time degradation after turning on casts optimization pass
• KT-80370 Add NO_INLINE attribute to some of runtime functions
• KT-80167 K/N: condense the nodes and edges in DevirtualizationAnalysis constraint graph
• KT-79535 Revert incorrect SAM conversion enhancements brought to K2

Fixes

• KT-79979 K2: ClassCastException when overriding extension property with delegation
• KT-82590 ClassCastException when instantiating class with generics implemented by fun interface and lambda
• KT-78881 K2: False positive "Assigned value is never read" in composable function
• KT-79276 Dexing fails with "Cannot read field X because is null" with 2.2.0
• KT-79547 "UnsupportedOperationException: Not supported" with inlining and value classes
• KT-79442 "Multiple annotations of type kotlin.coroutines.jvm.internal.DebugMetadata": 2.2.0-Beta1 generates broken code with JVM default suspend methods in interfaces
• KT-80744 Kotlin failure on lambda with type parameter
• KT-81618 "Number of arguments should not be less than number of parameters" on JVM on Kotlin 2.3.0-Beta1
• KT-82869 Green-to-Red change in 2.3 after prioritizing non-suspend-function-type overloads
• KT-79611 "IllegalStateException: couldn't find inline method": Exception during incremental compilation
• KT-78895 Consider dropping isLocalInFunction and FirClassLikeDeclaration.isLocal
• KT-82040 Native: ClassCastException: PointerInputChange
• KT-81924 K2: "Cannot infer type for this parameter", "Overload resolution ambiguity between candidates"
• KT-80864 K2: MissingVal cannot be reassigned diagnostic for Java final fields (crashes in runtime withIllegalAccessError)
• KT-71420 Report error when reified type parameter is inferred to intersection type
• KT-79451 Rework approach to recursive types approximation
• KT-78413 Kotlin Debugger: value classes as context parameters have incorrect names in Variables View during debugging
• KT-82138 Debugger: Cannot evaluate JvmInline value class parameter
• KT-82381 ArrayIndexOutOfBoundsException while FirDiagnosticsCompilerResultsReporter tries to print code as part of a warning log
• KT-81068 Corrupted Unicode paths passed or used in the compiler
• KT-79783 KDoc parser: Links aren't rendered if the line has an indent of 4 or more
• KT-80549 Call of Java method with type parameter bounds: Expected FirResolvedTypeRef with ConeKotlinType but was FirJavaTypeRef
• KT-82132 False-positive type mismatch with -language-version 2.2
• KT-81988 K2: Any?.toString() causes NPE inside lambda with Java
• KT-81652 Native: ClassCastException: ApplicationForegroundStateListener.Companion
• KT-76479 Backend. JVM: Report errors on exposure of types in inline functions
• KT-82022 K/N: Unexpected "Annotation@JvmInline is missing on actual declaration" warning with value classes
• KT-80250 ISE: flow for PostponedLambdaExitNode not initialized - traversing nodes in wrong order?
• KT-76344 Drop language version 1.9 for non-JVM platforms
• KT-76343 Drop language version 1.8
• KT-80330 K2: NPE at org.jetbrains.kotlin.fir.resolve.calls.FirCallResolver.createResolvedNamedReference
• KT-80400 K2: AbstractMethodError on fun interface implementation inheriting from an interface compiled with -jvm-default=disable
• KT-9111 Improve diagnostic for call with access to outer class from nested class
• KT-78280 Implement the sourcelessKtDiagnostics
• KT-74999 K2: KotlinNothingValueException within Extension Function
• KT-81254 "AssertionError: There should be at least one non-stub type to compute common supertype": Parser issue during generic type inference
• KT-53237 NI: Frontend ignores generic bound when inferring types
• KT-81186 Only allow local type aliases in REPL/scripts until full stabilization
• KT-80929 IC Native: Undefined symbols on ktor
• KT-81657 K2: put warning about "exposing package-private in internal" under experimental language feature
• KT-81241 Konanc exit while lowering org.jetbrains.kotlin.ir.util.IrUtilsKt.remapTypeParameters
• KT-74819 K2: False-positive overload resolution ambiguity for flatMap inside PCLA
• KT-81547 Stabilize DFA-based exhaustiveness
• KT-79274 Frontend implementation of name-based destructuring
• KT-79506 Contract for getter and setter doesn't work if a property is called from another module
• KT-58988 K2: Deprecate exposing package-private parameter of internal method
• KT-80711 IC Native: NPE during link on ktor
• KT-77727 Move some of the extra checkers to the default list
• KT-76136 Switch latest stable version in Kotlin project to 2.3
• KT-81257 Native: "Unexpected boolean predicate" when generating 'static_cache'
• KT-81525 Report REDUNDANT_SPREAD_OPERATOR on (*) instead of argument expression
• KT-81522 Fix Light TreeSPREAD_OPERATOR diagnostic positioning
• KT-77008 K2: Incorrectly force casting to a wrong type
• KT-78127 K2: Too precise inference for if/when with expected type in assignment
• KT-80208 K2: ClassCastException: "class java.util.ArrayList cannot be cast to class java.lang.Void" type inference picks Void for generic function
• KT-75797 Native: find a way to handle generates C bridges in inline functions
• KT-78819 K2: False positive ABSTRACT_MEMBER_NOT_IMPLEMENTED in KJK hierarchy
• KT-80003 Kotlin/Native: deprecate eager GlobalData initialization
• KT-79231 Inconsistent InnerClass entry flags for abstract inner enum
• KT-20677 Improve diagnostic about implicit default constructor absence for expected annotation class
• KT-81385 Missing error of nullable expression in class literal in case of reified type parameter
• KT-81251 Smartcast doesn't work for an effectively private inline function
• KT-81245 Automatic smart cast on properties with EBF is allowed on inlined property accessors
• KT-81222 Custom getter is allowed on a property with redundant EBF
• KT-80795 Wrong type cast is added for IMPLICIT_COERCION_TO_UNIT
• KT-81141 Fix FirUnsupportedArrayLiteralChecker to forbid array literals inside non-annotation contexts
• KT-81383 Return type of anonymous function used asrun argument is incorrectly inferred toNothing
• KT-80577 "Return type mismatch" for self-referential types used as generic parameters
• KT-75215 KDoc: references from@param tag are rendered as plain text
• KT-79887 K2 Compiler Internal Error in 'FirFakeOverrideGenerator.checkStatusIsResolved' Method
• KT-78125 false-negative shadowed contextual overload warning on local declarations
• KT-81198 Move type and type parameter annotations from jvm_metadata.proto to metadata.proto
• KT-81057 Wrong handling of boxing during redundant casts optimization
• KT-81191 K2: "null cannot be cast to non-null type ConeTypeParameterLookupTag" with invalid code
• KT-80285 IJ monorepo: broken compilation after 2.2.20-RC update
• KT-81115 Allow converting lambda with explicit parameter when assigning to variable of an extension function type
• KT-74588 Redundant checkNotNull intrinsics instructions for Java generic methods
• KT-78390 UnmuteFusStatisticsIT.testKotlinxPlugins() after AtomicFU updateskotlin-metadata-jvm
• KT-79369 Forbid typealiasing for all compiler-required annotations
• KT-69294 K2: ReportCONSTRUCTOR_OR_SUPERTYPE_ON_TYPEALIAS_WITH_TYPE_PROJECTION_ERROR instead ofEXPANDED_TYPE_CANNOT_BE_INHERITED after switching to LV 2.2
• KT-81064 Wrong safe call null check handling during redundant casts optimization
• KT-80871 StackOverflowError on AnnotationTarget.TYPE
• KT-80908 K2: Compiling type annotation with self-annotated vararg fail with exception
• KT-81018 ISE "IR class for Foo not found" on missing dependency when lowering SAM constructor
• KT-80936 NON_PUBLIC_CALL_FROM_PUBLIC_INLINE :@PublishedApi doesn't work for fun interfaces
• KT-75748 StackOverflowError when reading array from metadata annotations
• KT-80606 KotlinIllegalArgumentExceptionWithAttachments when using property itself in explicit backing field initialization
• KT-80940 K2: Exception in FIR2IR with AnnotationTarget.TYPE with self-annotated non-vararg default argument and usage in child module
• KT-80538 KaFirDiagnostic.EmptyRange doesn't work in most of the cases
• KT-80524 Class is not abstract and does not implement abstract member when compiling with kotlinc-jklib
• KT-80597 Apply fix forCVE-2024-7254 to our fork of protobuf 2.6.1
• KT-80849 K2:ConstValueProviderImpl doesn't distinguish files with same name and package
• KT-80602 Exhaustiveness checker improvements for 2.3
• KT-80735 Support || return/throw shortcut in unsed return value checker
• KT-79651 Report a warning about an unused return value only on the function name
• KT-80719 False positive: "Redundant visibility modifier": when overriding protected methods as "public"
• KT-80434 K2: DSL marker doesn't work with lambda fields
• KT-80383 Getter without a body is allowed on a property with an explicit backing field
• KT-80446 Explicit visibility modifiers are allowed on EBF
• KT-80378 ClassCastException on callable reference to a property with EBF
• KT-80377 Fir2Ir: "Cannot determine expected receiver type" for callable reference to a property with EBF outside of class
• KT-80455 K2: StackOverflowError in when exhaustiveness checker on red code
• KT-72862 [Native caches] Umbrella for failing codegen/box tests for corner cases in synthetic accessors
• KT-20278 NO_TYPE_ARGUMENTS_ON_RHS: Confusing diagnostic for inner class of generic outer class
• KT-80418 Property with EBF with functional type isn't resolved if its type is Any
• KT-80469 Functional type from property is always used for explicit backing field
• KT-80535 Missing INITIALIZER_TYPE_MISMATCH for EBF
• KT-80445 Private visibility is possible for a property with EBF
• KT-80164 Move name generation for unnamed context parameters to frontend
• KT-80684 Line breaks are lost in multi-line diagnostic messages since 2.3.0
• KT-78112 RETURN_VALUE_NOT_USED is reported for local function even if it isn't marked with annotation in CHECKER mode
• KT-48311 Incorrect LINENUMBER after if with a suspend call
• KT-80688 Bad SourceDebugExtension caused by enhanced coroutines debugging
• KT-73851 Native: compilation fails with ClassCastException with genericSafeCasts=true
• KT-77593 Add a warning when@IgnorableReturnValue is inconsistent between expect/actual functions
• KT-79386 Confusing error message when named parameters are used for java method calls
• KT-80600 K2: Private and final modifiers are allowed on setter of open delegated property
• KT-77101 Invoke on callable reference is considered ignorable
• KT-79923 Remove lookup of@IgnorableReturnValue annotation from FirReturnValueOverrideChecker
• KT-80517 Synthetic kotlin.Any members in data classes are missing@MustUseReturnValue
• KT-80194 VAR_TYPE_MISMATCH_ON_OVERRIDE: doesn't mention the inferred type
• KT-80484 K2: ClassCastException due to fake source for implicit lambda parameter (RedundantNullableChecker)
• KT-80592UninitializedPropertyAccessException when anayzing annotations on members of anonymous classes
• KT-80399 Anonymous Kotlin class incorrectly warns about deprecated java override despite '@Deprecated' annotation
• KT-79610 Adding CocoaPod to Kotlin/Native MPP triggers IR serialization failure and commonizer errors
• KT-79951 Infinite loop in parsing incomplete full form destructuring
• KT-79866 kotlinc 2.2.0 silently emits 'NonExistentClass' instead of reporting an error
• KT-79777 Argument type mismatch on value of complex type with a captured raw type argument
• KT-78664 False positive VARIABLE_NEVER_READ and ASSIGNED_VALUE_IS_NEVER_READ on function type variable with splited declaration and assignment
• KT-79496 False positive "when must be exhaustive" in triangle interface/class hierarchy
• KT-79774 KtDestructuringDeclaration.getLPar & getRPar are broken
• KT-80391 K2: Only one context parameter is mentioned in the [NO_CONTEXT_ARGUMENT] diagnostic
• KT-79785 ktypew:kotlin.collections.List already exists error using Swift Export
• KT-78879 "Sealed types cannot be instantiated": Can't instantiate Java-defined sealed Class from Kotlin
• KT-21598 Extension is shadowed by member should not be reported when member is deprecated with HIDDEN level
• KT-79622 FUNCTION_EXPECTED: Misleading 'expression cannot be invoked as a function' when inaccessible with private lambda
• KT-80255 [EXTENSION_FUNCTION_IN_EXTERNAL_DECLARATION] can be attached to the receiver type of a functional type
• KT-79816 Java Interfaces implemented by delegation have non-null return checks
• KT-80177 Improve message of RECEIVER_SHADOWED_BY_CONTEXT_PARAMETER in case of member extension
• KT-79770 There is no RECEIVER_SHADOWED_BY_CONTEXT_PARAMETER if the usage of fun is from inside the class
• KT-79430 False positive EXTENSION_SHADOWED_BY_MEMBER on overridden member extension
• KT-62934 Incorrect line mapping inside inline lambda after non-local return
• KT-79545 K2: no error on crossinline lambda usage in anonymous object base constructor call
• KT-79643 HAS_NEXT_FUNCTION_AMBIGUITY and NEXT_AMBIGUITY diagnostics are always ignored in favor of HAS_NEXT_FUNCTION_NONE_APPLICABLE and NEXT_NONE_APPLICABLE
• KT-79327 Modifier 'private' is not applicable to 'value parameter' is reported for context parameters
• KT-76453 K2 IDE: autocomplete freeze
• KT-77182 A function in a file annotated with@file:MustUseReturnValue doesn't produce a warning when it is used from compiled code
• KT-78541 Jspecify: Unsound platform type despite@NullMarked for an override with a generic-subclass return type
• KT-79672 'when expression must be exhaustive' even after using 'require()'
• KT-71306 K2 IDE / Kotlin Debugger: “Cannot find local variable 'block' with type kotlin.jvm.functions.Function0” on evaluating lambda arg inside inline function
• KT-76991 K2 IDE / Kotlin Debugger: ISE “Couldn't find declaration file for” on evaluating local fun when the scope has also inline fun from another file call
• KT-79877 K2 IDE / Kotlin Debugger: failed evaluations of a code fragment capturing local data class
• KT-77401 [FIR]ParameterNameTypeAttribute.name doesn't support@ParameterName with compile-time constant property argument
• KT-79682 Fix partially uninitialized locals after coroutine spills insertion
• KT-79562 NPE when passing non-lambda argument of nullable non-suspend function type into function that accepts nullable suspend function type
• KT-79693 NotImplementedError: An operation is not implemented: Unknown file with KMP separate compilation
• KT-79662 Unused return value checker doesn't work for com.google.errorprone.annotations.CheckReturnValue
• KT-79781 Missing MISSING_DEPENDENCY_CLASS when using type alias with inaccessible RHS
• KT-77772 Only report exposed type on qualifier if it's resolved to an object
• KT-79765 K2. Do not report ignore return value for unresolved reference
• KT-79017 False negative REDECLARATION on private nested class
• KT-79519 Nested type alias is unreachable from another module
• KT-72039 StackOverflowError on calling keySet on a Kotlin subclass of Java subclass of ConcurrentHashMap
• KT-75843 K2: incorrect line numbers in an if-expression with a super-call
• KT-77504 Add a warning when@IgnorableReturnValue is inconsistent on overrides
• KT-78389 Perform version 2.3 boostrapping
• KT-79092 Crash on default argument in function in fun interface
• KT-77729 Package-level@NullMarked does not work when kotlinc sees .javasource files
• KT-79013 False negativeNOT_YET_SUPPORTED_IN_INLINE on inline local functions inside inline functions
• KT-79139 False positive CONFLICTING_OVERLOADS for context parameters instead of receivers
• KT-35305 Address the overload conflict resolution between unsigned and non-primitive types
• KT-42096 No diagnostic reported oninline modifier on an enum entry
• KT-79355 Failed to fix the problem of desugaredinc with new reverse implies returns contract
• KT-79277 Implies returns contract doesn't affect the return type of the function if it is in the argument position
• KT-79271 Implies returns contract doesn't impact exhaustiveness
• KT-79218 SMARTCAST_IMPOSSIBLE for top‑level extension‑property getter despite returnsNotNull contract
• KT-79220 returnsNotNull contract ignored on extension function with nullable receiver
• KT-79354 IllegalStateException: Debug metadata version mismatch. Expected: 1, got 2 with compiler 2.2.20-Beta1 and stdlib 2.2.0
• KT-77986 K2: False negative: "Local classes are not yet supported in inline functions"
• KT-79456 Redeclaration conflict checks of private top-level classifiers rely on an incorrect containing file
• KT-79125 RVC full mode: delegated interfaces are not checked
• KT-63720 Coroutine debugger: do not optimise out local variables
• KT-78595 type variable leak on a generic property as a call argument given an unstable smart cast
• KT-79076 'IllegalStateException: Cannot serialize error type: ERROR CLASS: Uninferred type' with Exposed column using recursive generic type
• KT-59807 K2: Replicate the MUST_BE_LATEINIT logic from K1
• KT-76782 K2: Incorrect resolve into unrelated invoke operator with wrong diagnostic
• KT-78066 TYPE_PARAMETER_OF_PROPERTY_NOT_USED_IN_RECEIVER error message does not account for context parameters
• KT-76065 Drop JavaTypeParameterDefaultRepresentationWithDNN feature
• KT-77808 Inference: recheck the code about DNN-related hacks
• KT-24202 NOTHING_TO_OVERRIDE if super-class reference misses generic arguments
• KT-78909 K2: Missing diagnostics [CYCLIC_INHERITANCE_HIERARCHY] for recursive class inheritance leads to StackOverflowError
• KT-75969 java.lang.IllegalArgumentException: source must not be null on red code
• KT-76902 Omit type-use annotations from diagnostics
• KT-17460 Diagnostics and intention on suspend function that is overriden with non-suspend one.
• KT-56665 K2: false positive RECURSIVE_TYPEALIAS_EXPANSION
• KT-78932 Contracts are allowed for open and overridden property accessors
• KT-77203 FIR: Consider adding destructured type to all COMPONENT_FUNCTION_* diagnostics
• KT-77685 "IllegalArgumentException: Sequence contains more than one matching element"
• KT-78452 Drop redundant frontend structures after fir2ir conversion
• KT-70507 Should parentheses prevent from plus/set operator desugaring?

Compose compiler

New features

• 98d3907 Introduce a compose group analysis module that produces a proguard/R8 mapping from group keys in bytecode.

Fixes

• b/419049140 Disabled memoization intry blocks
• KT-81081 Generate Compose-specific proguard mappings when Compose compiler plugin is applied.
• b/431025881 [Compose] Clean up runtime version checker
• b/365922168 Addjava.util.Locale to the list of known stable classes
• b/407549020 Introduce a registry of known stable markers
• b/417989445 Added a diagnostic to restrict usages ofrunCatching in
  @Composable functions
• KT-80294 Fix crash with inline@Composable function reference
• b/430140896 Fix IrSourcePrinter output for when branch check and typechecks
• CMP-9167 iOS: Platform declaration clash: The following functions have the same IR signature

IDE. Gradle Integration

• KT-46273 MPP: Don't fail import for case of missed platform in source set structure
• KT-46417 [UNRESOLVED_REFERENCE] For project to project dependencies of native platform test source sets
• KT-44845 After update to Kotlin 1.4.30 all external dependencies is unresolved in IDE with kotlin.mpp.enableGranularSourceSetsMetadata=true
• KT-46142 K/N distribution is unavailable from IDE with multiplatform hierarchical project structure enabled

IR. Actualizer

• KT-77337IrNoExpectSymbolsHandler finds expect class reference after enabling annotation traversal in IR
• KT-80002 Investigate the need for map copying in IrCommonToPlatformDependencyExtractor.kt
• KT-80131 KMP Separate Compilation: No override for FUN IR_EXTERNAL_DECLARATION_STUB name:
• KT-80064 KMP Separate Compilation: ClassCastException: class org.jetbrains.kotlin.ir.symbols.impl.IrTypeAliasSymbolImpl cannot be cast to class org.jetbrains.kotlin.ir.symbols.IrClassSymbol
• KT-80051 KMP Separate Compilation: Actualization of common dependencies failed on 'PROPERTY FAKE_OVERRIDE name:modCount visibility:protected modality:FINAL [fake_override,var]'
• KT-79998 KMP Separate Compilation: java.lang.IllegalStateException: No override for FUN IR_EXTERNAL_DECLARATION_STUB name:

IR. Inlining

New Features

• KT-70360 KLIBs: Uniformly handletypeOf() calls at 1st/2nd stages of compilation

Performance Improvements

• KT-69497 Crossinline lambda is allocated on K/N & JS

Fixes

• KT-78673 Make fakeOverrideLocalGenericBase not using red code
• KT-78537 [Inliner] Incorrect KFunction.name of a reference to inlined local function
• KT-74892 Investigate passing inline lambda as argument of another inline function
• KT-81673 False warnings about ABI change in dependencies in library mode in 2.3.0-Beta1
• KT-81713 [Inliner] Compilation of inline function with recursive call applied to TODO() fails with an internal error
• KT-80653 [IR Inliner] Space: "Local declarations should've been popped out by this point"
• KT-78392 CommonPrefix: Add a way of stopping execution when one of the phases is unsuccessful
• KT-80927 [Native] Review intrinsics with PublishedApi
• KT-81070 [Inliner] kotlin/Any is unbound
• KT-80628 KLIB inliner: Not enough information about the "full" mode
• KT-69516 Double-inlining for Native: Enable visibility checks after 1st phase of inlining
• KT-79334 Unify intrinsics used on 1st phase of IR inliner in KLIB-based compilers
• KT-80610 KLIB inliner: Always apply cross-module inlining to pre-processed inline functions
• KT-80565 KLIB Inliner: Add a special annotation to prohibit inlining of marked inline functions in stdlib on 1st compilation phase
• KT-80883 [Inliner] Run pre-serialization lowerings in all testrunners
• KT-77876 IrVisibilityChecker: Different set of exceptions for 1st and 2nd compilation stages
• KT-80693 [IC] Split IC invalidation tests for cross-module IR Inliner
• KT-79718 KLIB inliner: Emit warning on generation ofpublic synthetic accessor when running in "explicit API mode"
• KT-80226 [IR Inliner] Generate constructor accessors as constructors, not static functions
• KT-80692 [IC] Split IC invalidation tests for intra-module IR Inliner
• KT-77103 [Inliner] IrLocalDelegatedProperty was not serialized, while its symbol and IrRichPropertyReference were.
• KT-80537 The expected error is not emitted from FirJsKlibSyntheticAccessorsTestGenerated and NativeKlibSyntheticAccessorsTestGenerated
• KT-78903 Unifycodegen/boxInline tests withcodegen/box
• KT-78989 Add missing PL tests for inline functions/property accessors
• KT-79771 kotlinx-coroutines-core: Public synthetic accessor generated with enabled KLIB IR inliner
• KT-79680IrConstructorSymbolImpl is unbound in lambdaWithoutNonLocalControlflow.kt
• KT-70849 Ensure correct debug info for intra-module IR inlining on the first compilation phase
• KT-79800 JS BE errors with default values when IR inliner is enabled
• KT-79352 Remove excessive validations fromValidateAfterAll... on the first stage
• KT-76599 MigrateIrValidationAfterInliningAllFunctionsPhase to the first stage of compilation
• KT-78245 Synthetic Accessors incorrectly copies default values
• KT-72594 [JS][Native] Add IrInliningFacade to test runners

IR. Interpreter

• KT-72356 K2 Native: IllegalStateException when annotation has the same source range as a constant in another file
• KT-72881 K2: incorrect empty array as annotation argument when parameter has default value

IR. Tree

Fixes

• KT-79371 Fix handling of broken SAM conversion in PL with enabled Rich References
• KT-81952 "IllegalStateException: Callable reference with vararg should not appear at this stage" for callable references to functions with generic vararg parameters
• KT-79739 Static synthetic accessors inside generic classes access its type parameters
• KT-78100 Track and annotate internal annotations with@PublishedApi to enable annotation visibility validation
• KT-80825 DropIrSerializationSettings.reuseExistingSignaturesForSymbols setting
• KT-79807 Broken IR tree invariants in IrReplSnippet after FIR2IR
• KT-77819 [IR] Fine-tune IrValidator's run after Fir2IR and IR plugins
• KT-70160 Remove IrDeclaration.parents after Anvil update
• KT-80454 LocalDeclarationsLowering: Clean-up the dead code
• KT-80819 Rework IrFileValidator to use Hashmap instead of ClassValue
• KT-80516 Kotlin-like IR dump: Don't render tailrec as lateinit
• KT-78856 Refactor LocalDeclarationsLowering to split it in smaller parts
• KT-79439 KLIB stdlib symbols loading: Split the result of merging of IrBuiltins with BuiltinSymbolsBase hierarchy into two parts (for 1st & 2nd phases)
• KT-79437 KLIB stdlib symbols loading: Drop loading functions from IrBuiltins and migrate usages to SymbolFinder functions and lazy filtering
• KT-79569 Unexpected error during DFG phase in Native due to PL issue with SAM conversion represented by rich reference
• KT-76601 IrValidatorConfig should have all checks disabled by default
• KT-69662 Deduplicate functioncreateTemporaryVariable
• KT-79440 KLIB stdlib symbols loading: Drop BuiltinSymbolsBase from plugin API
• KT-78960 [FO] Limit static fake overrides generation for static functions
• KT-76813 IR validator: not all symbols/references are visited

JVM. Reflection

• KT-79020 Suspend lambdas return type is shown as ??? in reflection
• KT-81967 isSubtypeOf: ClassCastException: CapturedKType cannot be cast to class AbstractKType
• KT-76521 Reflection: change KType representation to avoid dependency on K1
• KT-81619 Reflection: Function supertype of a FunctionN class has flexible type in new implementation
• KT-74529 Context parameters support in reflection
• KT-80901 Reflection: incorrect translation of raw types in the new implementation
• KT-74624 Reflection: KClassifier.createType(...) ignores annotations parameter
• KT-80203 Reflection: provide a way to use legacy K1-based implementation
• KT-80236 Reflection: KType.toString for raw types no longer renders "(raw)"
• KT-79206 Reflection: suspend functional type classifier is null

JavaScript

New Features

• KT-80401 Kotlin/JS support fordefault export in generated JavaScript
• KT-79284 Use BigInt64Array for LongArray
• KT-79222 K/JS: Allow using Long in exported declarations
• KT-79394 Add the possibility to write common external declarations between JS and WasmJS targets

Performance Improvements

• KT-57128 KJS: Use BigInt to represent Long values in ES6 mode

Fixes

• KT-79928 Allow JsModule/JsNonModule/JsQualifier invocation on per-entity level
• KT-79514 java.lang.IllegalStateException: IrClassSymbolImpl is unbound. Signature: kotlin.js/Promise|null[0] on running jsBrowserTest
• KT-82005 KJS: "TypeError: callAgent.jsonRpcCall_ij3z26_k$ is not a function" after code change in 2.3.0-Beta1/2
• KT-79359 Kotlin/JS: Suspending function doesn’t return Unit on es2015
• KT-79089 KJS: Could not load reporter / Cannot find module 'mocha' when running jsNode tests
• KT-56281 KJS: Can't export suspend functions
• KT-79926 Wrong export of interfaces with companions with ES Modules
• KT-80168 Allow@JsStatic inside interface companions
• KT-70222 Remove legacy JS BE-related CLI flags
• KT-81424 Kotlin/JS: Cannot Get / in a simple running application
• KT-80873 KJS: Stdlib requires ES2020-compatible JS engine due to BigInt type literal
• KT-81066 Wasm, JS: Remove redundant logging in compiler output
• KT-72833 KJS: Source maps have incorrect sources paths inper-file
• KT-74055 KJS:@JsPlainObject adds JS code even if marked interface is not used
• KT-72474 KJS:@JsPlainObject doesn't honour -XXLanguage:+JsAllowInvalidCharsIdentifiersEscaping
• KT-79644 BigInt enabled for ES 2015 despite being an ES 2020 feature
• KT-52771 KJS: Pair should be exported to JavaScript
• KT-79704 Unify variance rendering between JS and other backends
• KT-69297 Deprecate referencing inlineable lambdas injs() calls
• KT-80086 [k/js] Resolving imported string literals
• KT-79066 [Kotlin/JS] jsNodeTest fails with SyntaxError when a test file has@file:JsExport and useEsModules() is enabled
• KT-77385 Investigate partial linkage problems for JS HMPP tests
• KT-79628 Remove IR nodes from ExportModel
• KT-79916 K/JS: "Uncaught TypeError" when using 'Xes-long-as-bigint' in compose-html
• KT-79050 KJS / IC: "Unexpected body of primary constructor for processing irClass"
• KT-79977 KJS: Long.rotateLeft returns incorrect result when BigInts are enabled
• KT-78831 AbstractFunctionReferencesLowering: fragile fake override generation
• KT-52230 KSJ IR: Applying identity equality operator to Longs always returns false
• KT-6675 KotlinJS: toInt() on external Long throws error
• KT-79184 K/JS: Further intrinsify BigInt-backed Long operations

Klibs

New Features

• KT-80761 K2: [K/N] Should reported klib usage include inheritance

Performance Improvements

• KT-80861 [Klib] Deduplicate IrFileEntry.name
• KT-80866 [Klib] Optimize size of IrFileEntry.line_start_offset
• KT-80438 Uncached KlibMetadataClassDataFinder.findClassData

Fixes

• KT-64237 Klib metadata: migrate to using the common annotations instead of klib-specific extensions in the compiler
• KT-80099 KLIB resolver: Could not find file because of missingklib extension in resolved symlink path
• KT-80999 Reuse existingIrKotlinLibraryLayout inKotlinLibrary for reading pre-processed functions
• KT-80290 Removeif and TODO incountInAsInlinedLambdaArgumentWithPermittedNonLocalReturns
• KT-80298 K/N: one-stage compilation is broken
• KT-79958 KLIB tool fails to render IR if there is IrErrorType in a lirbrary
• KT-75241 Move ExperimentalLibraryAbiReader to a publishable artifact
• KT-76260 MakeIrRichCallableReferencesInKlibs lang feature stable in LV=2.3
• KT-61552 [PL] IndexOutOfBoundsException in SAM conversion with substituted function
• KT-74417 Deduce the metadata version based on LV in KLIB-based backends
• KT-75980 [Klib] Reduce serialized size of IrFileEntries for sparse usage of another source files
• KT-73826 DeduplicateIrFileEntry that is serialized insideIrInlinedFunctionBlock

Language Design

• KT-76926 Allow return in expression bodies if return type is specified explicitly
• KT-78866 Show an error for implicit receiver shadowed by context parameter
• KT-81561 Update nested type aliases KEEP to reflect local type aliases support
• KT-81015 Stabilize nested type aliases
• KT-32619 JS: return Promise whencontinuation is not provided
• KT-78976 Decide if K2 should support local functions inside of local inline functions
• KT-79308 Ability to actualize empty interfaces as Any
• KT-48872 Provide modern and performant replacement for Enum.values()
• KT-28850 Prohibit protected visibility in final expected classes

Libraries

New Features

• KT-81092 Uuid: support generation of version 7 uuids with a given timestamp
• KT-78463 Annotate wasm and JS targets of kotlin-stdlib with@IgnorableReturnValue when appropriate
• KT-74444 EnumEntries type should implement RandomAccess
• KT-78462 Annotate kotlin-stdlib-jvm with@IgnorableReturnValue where appropriate

Performance Improvements

• KT-72111 Change Duration.parseOrNull logic to not throw exceptions internally

Fixes

• KT-82901Long.MIN_VALUE.milliseconds produces invalid denormalized Duration
• KT-81995 K/N: CMP: Undefined symbol _kfun:kotlin.time.Duration.kotlin.time.Duration
• KT-56822 Deprecate Number.toChar() with error deprecation level
• KT-81078 Increase kotlin.io.createTempDir and createTempFile deprecation level to ERROR
• KT-74493 Deprecate String.subSequence(start, end) with error and drop it in the future
• KT-79192 Increase InputStream.readBytes(Int) deprecation level to HIDDEN
• KT-80778 Stabilize kotlin.time.Clock and kotlin.time.Instant
• KT-81043 String.toBigDecimalOrNull rejects strings accepted by String.toBigDecimal
• KT-81477 Uuid.Companion.generateV* are missing SinceKotlin annotation
• KT-81478 FileTreeWalkTest.withDirectoryFilter fails on Windows
• KT-74411 Introduce Uuid.generateV4() and generateV7()
• KT-80530 Annotate Kotlin/Native stdlib with must-use value/@IgnorableReturnValue when appropriate
• KT-79791 Duration.parse incorrectly handles negative decimal seconds in ISO-8601 format
• KT-80619 [KLIBs] Enable intra-module inliner in stdlib & kotlin-test
• KT-76773 stdlib: contextOf's type argument can be inferred via contextOf's context argument
• KT-71822 Intersection with (subtraction from) an identity set may produce incorrect results
• KT-80431 Remove suppression of "ACTUAL_ANNOTATIONS_NOT_MATCH_EXPECT" from stdlib
• KT-80605 Rename MustUseReturnValue -> MustUseReturnValues
• KT-69947 KLIB stdlib: All intrinsics that can be used in KLIBs with inlined IR must be included in stdlib ABI dump
• KT-59044 Improve various aspects of TimeSource documentation
• KT-80544 Mark controversial path extensions (like .deleteRecursively()) as ignorable
• KT-80603 K/N and K/Wasm: \p{N} category is not supported
• KT-80661 ArrayDeque.lastIndexOf may return -1 for an element present in the deque
• KT-80390 ArrayDeque.indexOf(null) wrongly returns 0 after removals
• KT-79094 Change signature of assertFailsWith or make lambda excluded otherwise
• KT-72028 Incorrect parameters order in IndexedValue documentation
• KT-80130 [stdlib] Commonize AssociatedObjects in commonNonJvmMain
• KT-80107 [stdlib] Move CancellationException to commonNonJvmMain
• KT-80179 Investigate why StringBuilder.length is not enhanced automatically
• KT-80046 Increase test coverage of Duration.parse[IsoString][OrNull] methods
• KT-76459 Remove comments about sorting stability in unsigned-type arrays
• KT-79489 Generate Stdlib API reference for webMain source set
• KT-78243 Drop JS- and Wasm-specific IrLinkageError classes
• KT-79108 Remove the default argument forlinkageError from kotlin.js.getPropertyCallableRef
• KT-79130 K/JS: Remove bodies from intrinsified Long methods
• KT-79239 K/Wasm: elementAt extension function of Array/PrimitiveArray/UnsignedArray does not throw IndexOutOfBoundException on incorrect index
• KT-79256 K/Wasm: MatchResult.groups raises a trap on invalid group index
• KT-57317 Repack EnumEntries from stdlib into the compiler

Native

• KT-80620 Bump minimal iOS and tvOS supported versions to 14.0
• KT-80624 Bump minimal watchOS supported versions to 7.0
• KT-79384 K/N: Application Not Responding: Thread Deadlock
• KT-80536 Native:DependencyDownloader seems to have no timeout

Native. Build Infrastructure

• KT-80147 Set proper LV and AV forkotlin-native/performance/buildSrc
• KT-79474 Kotlin/Native: fix breakpad build
• KT-79215 Kotlin/Native: fix distInvalidateStaleCaches on windows

Native. C and ObjC Import

• KT-79752 Native: make cinterop generate CCall.Direct annotations
• KT-79753 Native: support CCall.Direct calls in the compiler
• KT-81312 Native: when-Xccall-mode direct is used, mark unsupported declarations with unresolvable symbol name instead of@Deprecated(ERROR)
• KT-79571 Xcode 26 beta 4: CInteropKT39120TestGenerated.testForwardEnum failed
• KT-80838 Cinterop fails with an error when Compilation works fine
• KT-49034 Kotlin/Native:cnames.structs.Foo resolves into wrong declaration

Native. ObjC Export

• KT-81906 NormalizeCFBundleIdentifier when producing Apple framework
• KT-78810 [ObjCExport] Enable explicit ObjC block parameter names by default
• KT-80271 ObjC/Swift Export: Remove Native platformCloneable checks
• KT-78604 Consider not inheritingKlibScope fromKaScope
• KT-79767 ObjCExport: private companion must not be exposed
• KT-79724 ObjCExport: extensions order
• KT-79548 ObjCExport: mangling difference between K1 and K2 when translating KotlinDurationCompanion
• KT-79475 ObjCExport: invalid property getter translation
• KT-79346 ObjCExport: Any method overrides
• KT-78871 ObjCExport: translation of keywordrelease with parameter generates invalid header

Native. Runtime. Memory

• KT-75918 Native: Deprecate -Xallocator=std
• KT-80678 Native: pagedAllocator=false sweep is slow
• KT-75916 Native: Enable sanitizer support with pagedAllocator=false

Native. Swift Export

Fixes

• KT-81355 Swift Export: Introduce a flag to turn off coroutines export
• KT-80969 Swift Export: Callsuspend function asasync on swift side
• KT-80111 Swift Export Build Fails Due to Errors in KotlinStdlib.swift
• KT-80884 Swift Export: support async in SIR
• KT-80185 Swift Export: IllegalArgumentException – Collection contains more than one matching element
• KT-79889 K/N: swift-export fails under several different conditions
• KT-79518 Swift export: represent kotlin.Any as swift.any
• KT-78603 Do not inherit SirAndKaSession from KaSession
• KT-79227 Swift Export: Fix First Release Issues
• KT-79521 '_CoroutineScope' is inaccessible due to 'internal' protection level
• KT-79181 Swift Export Fails When Using T: Comparable Generic Constraint in Kotlin Classes

Tools. Ant

• KT-75875 Remove Ant support

Tools. BCV

• KT-80313 Add ability to generate dump from jar files [ABI Tools]

Tools. Build Tools API

New Features

• KT-78194 BTA: port the JVM prototype to the new design
• KT-79409 BTA: Support removed compiler arguments properly
• KT-78193 BTA: Implement core infrastructure according to the new design
• KT-78196 BTA: implement API adapter for the prototype implementation
• KT-77999 BTA: Generate BTA options from compiler arguments descriptions

Fixes

• KT-75357 CompilationService.loadImplementation(loader) Expects aClassLoader, but Fails if its not aURLClassLoader
• KT-73090 Gradle 8.11 kotlin compilation fails when run with -Pkotlin.compiler.runViaBuildToolsApi=true
• KT-81321 Deprecate old BTA prototype API
• KT-81602 BTA: rename KotlinToolchains.jvm@JvmName for a more Java-friendly API
• KT-75356 Failing to pass a-d argument causes Build Tools API to NPE
• KT-81130 BTA: using KotlinVersion from stdlib in the API breaks when using isolated classloader
• KT-78195 BTA: migrate the test infrastructure from the prototype to the new design

Tools. CLI

• KT-81077 Add JVM target bytecode version 25
• KT-79867 CompilerConfiguration.configureSourceRoots puts obfuscated file paths instead of ones passed onclasspath to CLIConfigurationKeys.CONTENT_ROOTS
• KT-80348 Expose 'XXLanguage' compiler argument as a normal argument
• KT-80428 KMP Separate Compilation: Handle friend dependencies
• KT-74590 Deprecate -Xjvm-default in favor of -jvm-default
• KT-80349 KMP Separate Compilation is enabled on non-KMP compilations
• KT-79982 Fix description of -Xjspecify-annotations
• KT-79403 Improve generator for deprecated CLI arguments
• KT-75968 Set proper lifecycle for all existing compiler arguments
• KT-79293 Create Language Features and compiler argument with parameter for new destructuring features

Tools. Commonizer

• KT-49735 [Commonizer] :commonizeNativeDistribution fails for projects with two or more same native targets
• KT-47523 MPP: Unable to resolve c-interop dependency if platform is included in an intermediate source set with the only target
• KT-48118 Commonized c-interop lib is not attached to common main source set
• KT-46248 MPP: Compile KotlinMetadata fails with Unresolved reference if only one native platform from shared source set is available

Tools. Compiler Plugin API

• KT-82563 Improve compiler error messages to identify incompatible plugins causing compilation failures
• KT-55300 Provide a mechanism to describe ordering and dependencies for compiler plugins
• KT-82099 Compiler plugin ordering has no effect
• KT-74867 LLFirIdePredicateBasedProvider matches local classes when it shouldn't
• KT-52665 DeprecateComponentRegistrar
• KT-75865 Provide an API for setting the file name for the file with top-level declarations generated by a plugin

Tools. Compiler Plugins

New Features

• KT-81091 [DataFrame] Receivers from FirExpressionResolutionExtension are not resolved in CodeFragment

Fixes

• KT-64339 Symbol Light Classes: No Arg compiler plugin generates synthethic constructor which is not seen from light classes
• KT-80429 Power Assert with "Run test using: IntelliJ": NoClassDefFoundError (org.jetbrains.kotlin.kotlinx.collections.immutable.ExtensionsKt) during compilation
• KT-79319 Lombok: NullPointerException onmvn compile when importing Java constants
• KT-81348 Incorrect bytecode mentioning error class/package is generated by kotlinx-serialization when private serializer in another module is not accessible
• KT-80944 FirUserTypeRefImpl cannot be cast to class FirResolvedTypeRef in maven project
• KT-80815 NoArg compiler plugin: Promote NO_NOARG_CONSTRUCTOR_IN_SUPERCLASS diagnostic from warning to error
• KT-80822 False positive NO_NOARG_CONSTRUCTOR_IN_SUPERCLASS reported for a class with explicit noargs constructor already present
• KT-53122 Constructors generated with NoArg have no@Metadata and are invisible for the frontend
• KT-74687 Kotlin Lombok: False positive when calling builder on Java record
• KT-80419 Remove bundled jetbrains annotations from kotlin-dataframe-compiler-plugin
• KT-79245 [AtomicFU] Drop K1/JS- and K1/Native-specific testrunners
• KT-79197 DataFrame: Cannot find local variable 'this@df' with type Scope0
• KT-73865 Incorrect type is generated for irPropertyReference during K/N transformation

Tools. Compiler plugins. Serialization

• KT-70345 Promote COMPANION_OBJECT_IS_SERIALIZABLE_INSIDE_SERIALIZABLE_CLASS diagnostic to error
• KT-79695 Serialization does not exclude field-less properties in 2.2.20-Beta2
• KT-79246 [Serialization] Drop K1-specific testrunners

Tools. Gradle

New Features

• KT-78199 Gradle: Migrate JVM compilation in KGP to the new BTA
• KT-45161 Gradle: Support registering generated sources with the Kotlin model
• KT-71602 Introduce KotlinTopLevelExtension

Fixes

• KT-67290 Deprecate usage of HasKotlinDependencies inside KotlinCompilation
• KT-80950 KGP breaks configuration cache when signing plugin with GnuPG is applied
• KT-64211 Provide support for the kotlin.internal.compiler.arguments.log.level property while running via build tools api
• KT-81719 Do not register swift export related configurations when it's not required
• KT-78741 Add FUS analytics for klib cross-compilation
• KT-75449 Update deprecation ofKotlinJsTestFramework#createTestExecutionSpec
• KT-64273 Gradle: remove symbols deprecated after KT-54312
• KT-74915 Make ExtrasProperty.kt internal
• KT-64992 Remove KotlinCompilation.source
• KT-82068 Workaround iOS Simulator start failure in IT
• KT-79482 Report webMain / webTest usage in FUS metrics
• KT-81199 Deprecate "org.jetbrains.kotlin.android" plugin
• KT-82244 Conflicting warnings when using AGP 9.0.0-alpha with built-in Kotlin disabled
• KT-81161 Gradle plugin api reference: compiler arguments types are not available
• KT-70251 Gradle: hide compiler symbols in KGP
• KT-81837 Run integration tests against AGP 8.13
• KT-77457 Compile against Gradle API 9.0
• KT-79238 Bump minimal supported AGP version to 8.2.2
• KT-75869 KGP JS - Update deprecated constructors
• KT-76720 Raise deprecation level to error for Kotlin*Options properties
• KT-79047 Gradle compileKotlin fails with configuration cache
• KT-81415 BTA: Duplicate daemons when compiling JVM + JS in KGP
• KT-80763 Add redirect link to error message when 'org.jetbrains.kotlin.android' plugin is used with built-in Kotlin
• KT-81038 Gradle: remove support for properties disabling precise task outputs backup
• KT-80808 Warning from kotlin-dsl with kotlin("jvm") on Gradle < 9.0 doesn’t suggest updating Gradle
• KT-80875 Gradle: runToolInSeparateProcess may fail on Windows with too long command line
• KT-79851 Emit an actionable warning/error on unsupported AV/LV configured bykotlin-dsl
• KT-77458 Run Gradle integration tests against Gradle 9.0
• KT-80172 Error message changes depending on the order of applying 'org.jetbrains.kotlin.android' and 'AGP' 9.0+ with built-in Kotlin plugin
• KT-76177 Remove deprecated classpath snapshot task inputs
• KT-79339 Remove additionalMetadata from compiler options DSL
• KT-73478 Add module level description
• KT-80083 KGP IT: fix tests on Windows
• KT-79034 Automatically disable cross compilation if it's not supported on the host
• KT-79408 A lot of errors files are created when compile Kotlin
• KT-78827 Rewrite Gradle compiler options DSL generator

Tools. Gradle. BCV

• KT-80687 Add description to Gradle tasks [ABI Validation]
• KT-80621 Move Gradle tasks into suitable groups [ABI Validation]
• KT-78625 Kotlin's built-in BCV generates empty .api files

Tools. Gradle. Compiler plugins

• KT-81827 Add a switch for mapping file tasks in Compose Gradle plugin

Tools. Gradle. JS

Fixes

• KT-79921 Web Tooling Gradle API does not respect webpack reconfiguration
• KT-81009 K/JS, Wasm: Promote deprecation of NPM and Yarn package manager internal functions
• KT-76019 Wasm/JS: Promote phantom-js for Karma deprecation to ERROR
• KT-81005 K/JS, Wasm: Promote deprecation of ExperimentalWasmDsl to Error
• KT-81010 K/JS, Wasm: Promote deprecation of internal JS functions to Error
• KT-81008 K/JS, Wasm: Promote deprecation of ExperimentalDceDsl to Error
• KT-81007 K/JS, Wasm: Promote deprecation of public constructors of JS declarations to Error
• KT-81006 K/JS, Wasm: Promote wasm declarations in "js" package deprecation to Error
• KT-81004 K/JS, Wasm: promote deprecation NodeJsExec.create to Error
• KT-75621 KJS / Gradle: Disable npm in --offline mode
• KT-79910 Wasm, JS: Upgrade NPM versions
• KT-76996 Wasm: js tasks triggers wasm subtasks
• KT-79237 Upgrade NPM dependencies versions

Tools. Gradle. Multiplatform

New Features

• KT-76446 Add kotlin-level dependency block to work the same way as commonMain/commonTest dependencies blocks

Fixes

• KT-61127 Remove scoped resolvable and intransitive DependenciesMetadata configurations used in the pre-IdeMultiplatformImport IDE import
• KT-81980 KGP warning gives incorrect suggestion for AGP application compatibility
• KT-81601 Withandroid.builtInKotlin=false AGP 9.0+, usingkotlin-multiplatform plugin will fail with aClass Cast Exception
• KT-81060 KMP stores common compilation dependency resolution in Configuration cache leading to error when deserializing (Android only)
• KT-80720 Gradle import of multiplatform project fails: "Failed to invoke getAssociateWith on KotlinJvmCompilation_Decorated"
• KT-81200 Deprecate 'androidTarget'
• KT-74005 Implement a prototype of Unified Klib support in Kotlin Gradle Plugin
• KT-77367 [uklib] Project dependency to kotlin-jvm module leads to failure in transform during IDE import
• KT-80785 Withandroid.builtInKotlin=false andandroid.newDsl=true, usingkotlin-android plugin will fail withClassCastException
• KT-81434 [uklib] androidCompileClasspath resolves java compatibility variant instead of android for uklib library
• KT-81469 [uklib] kmpPublicationStrategy affects resolution during import for androidTarget
• KT-81249 Kotlin 2.2.20 broke KMP implementation of Parcelize
• KT-77066 Promote kotlinArtifacts deprecation to an error
• KT-74955 Remove resources resolution strategy completely
• KT-62614 Remove legacy kotlin-gradle-plugin-model
• KT-79559 AGP complains about configurations resolved at configuration time due to KMP partially resolved dependencies diagnostic
• KT-78993 The value for property '*' property 'dependencies' is final and cannot be changed any further
• KT-76200 TestModuleProperties.productionModuleName for JVM module isn't present with 2.1.20-RC
• KT-55312 Replace "ALL_COMPILE_DEPENDENCIES_METADATA" configuration with set of metadata dependencies configurations associated per set
• KT-52216 HMPP / KTOR: False positive "TYPE_MISMATCH" with Throwable descendant
• KT-54312 TCS: Replace CompilationDetails abstract class hierarchy by composable implementation
• KT-55230 Remove metadata dependencies transformation for runtimeOnly scope

Tools. Gradle. Native

• KT-80675 Commonized cinterops between "test" compilations produce an import failure
• KT-77732commonizeCInterop failed with "Unresolved classifier: platform/posix/size_t"
• KT-81510commonizeCInterop exception with 'kotlinNativeBundleConfiguration' not found
• KT-81134 Native: Gradle configuration failure likely related to Klibs cross-compilation
• KT-77486 Remove bitcode DSL
• KT-64107 Kotlin Gradle plugin allows native binaries to have bothdebuggable andoptimized flags set totrue
• KT-74910 BumpdestinationDir in CInteropProcess to hidden
• KT-74911 Promote CInteropProcess.konanVersion to hidden
• KT-74864 Enable exporting KDocs by default to ObjC
• KT-72705 K/N: compile task cache can not be used due to 'artifactVersion' input property

Tools. Gradle. Swift Export

• KT-81465 Swift Export package is build with wrong target
• KT-81460 [KGP] Crash in SwiftExportRunner due to older stdlib
• KT-79524 NoSuchMethodError: 'java.lang.String org.gradle.api.artifacts.ProjectDependency.getPath() for swift export with dependency export fro gradle < 8.11

Tools. Incremental Compile

• KT-75864 Implement a conservative mechanism of the IC with compiler plugins generated top-level declarations
• KT-55982 K2: Consider global lookups from plugins in incremental compilation
• KT-79504 Implement an API to provide IC lookups from backend plugins
• KT-75657 Fix difference in incremental compilation scenarios in BTA in-process vs daemon compilation mode
• KT-79541 Refactor tracking of files relation in IC
• KT-74628 Incremental compilation runner does not check compiler exit code before mapping sources to classes

Tools. JPS

• KT-77347 Support file-less compatible IC approach

Tools. Kapt

• KT-79138 K2: KAPT Java Stub Gen:Unresolved reference with@kotlin.Metadata in Java in 2.2.0
• KT-79133 K2 kapt: class literal with typealias is not expanded
• KT-79305 K2 kapt: ISE "Cannot evaluate IR expression in annotation" on typealias with unresolved expansion
• KT-79136 K2 kapt: unresolved nested class references in annotation arguments are generated without outer class names
• KT-71786 K2Kapt: Stubs generation does not fail on files with declaration errors
• KT-80843 K2: KAPT: Crash on any data class with duplicate properties: "Sequence contains more than one matching element"
• KT-73411 Removekapt.use.k2 property and code which allows to use K2 with K1 kapt
• KT-79641 Kapt: too much information is printed in verbose mode

Tools. Maven

• KT-82180 kotlin-maven-plugin: IC succeeds after dependent source deletion
• KT-78201 Maven: migrate JVM compilation to the new BTA
• KT-81414 2.2.20 regression: OOM (Compressed class space) when in-process
• KT-81435 Maven: Improve BTA classloader reusage
• KT-81681 Maven: "NoClassDefFoundError" on a second test run
• KT-81218 Kotlin Maven Plugin 2.2.20: Java classes not resolved with enabled incremental compilation without daemon

Tools. Performance benchmarks

• KT-79709 Add-Xdetailed-perf CLI flag to control verbosity of performance logs
• KT-79226 [K/N] Add performance measurement for native backend lowerings

Tools. REPL

• KT-80062 ReplSnippetLowering sometimes produces IrConstructorCall with too many arguments

Tools. Scripts

• KT-80071 Kotlin script mode produces invalid IR: "value that is not available in the current scope"

Tools. Statistics (FUS)

• KT-77407 Add performance measurement for prefix lowerings
• KT-79455 [FUS] Collect KSP plugin version
• KT-79090 Integrate dynamic stats intoMarkdownReportRenderer

Tools. Wasm

• KT-82365 K/Wasm: NodeRun tasks in Wasi depend on kotlinWasmToolingSetup
• KT-81313 K/Wasm: update Node.js to 24.x
• KT-81315 K/Wasm: update Node.js to 25.x
• KT-80582 Multiple reloads when using webpack dev server after 2.2.20-Beta2
• KT-80896 K/Wasm: debug tests only once
• KT-78921 K/Wasm: don't generate empty yarn.lock file