v2.3.20: Kotlin 2.3.20

Changelog

Analysis API. FIR

New Features

• KT-78090 Implement stubs support for new conditional returns and holdsIn contracts

Fixes

• KT-82948 'FirRegularClass' expected as a containing declaration, got 'FirTypeAliasImpl'
• KT-83467 Package-level JSpecify annotations are ignored when coming from jars or libraries
• KT-82057 K2. Cannot infer type parameter 'R' in Ktor routing post() function with explicit response type
• KT-82846 AA: unresolved KtExpression.expressionType for the reference to the parameter with default value
• KT-80485 False positive UNRESOLVED_REFERENCE on nested interface from super-super class in the super type position inside an anonymous object
• KT-82772 Flaky false positive deprecation warning on PersistentMap.put in Kotlin repo in IDE mode
• KT-76487 StdLibSourcesLazyDeclarationResolveTestGenerated.testWrappedInt is unstable
• KT-82618 Various tests are failing with NPE in kt-master after updating the compiler on 19.11.25
• KT-82076 Error querying members of JavaClass created for SymbolLightClassForAnnotationClass during library analysis
• KT-71596 Include Js/Wasi checkers in AbstractLLFirDiagnosticsCollector
• KT-82085 No OUTER_CLASS_ARGUMENTS_REQUIRED on type parameter bound in IDE
• KT-81873 Provide a way of including traces in phase JFR events
• KT-71929 Consider leaving the non-post-compute version at EnhancementSymbolsCache.enhancedFunctions

Analysis API. Infrastructure

• KT-83173 Analysis API Tests: Library names with RC versions aren't sanitised
• KT-65140 LL FIR: Implement AbstractFirPsiJsDiagnosticTest for LL FIR
• KT-82212 [Analysis API, LL FIR] Implement AbstractDiagnosticsFirWasmTest and AbstractDiagnosticsFirWasmWasiTest for LL FIR

Analysis API. Light Classes

• KT-82227 Value classes should expose regular static methods

Analysis API. PSI

• KT-81710 'KtTypeReference.getTypeText' does not account for 'suspend' modifier on suspend lambdas
• KT-82258 Prepare PSI for migration from context receivers to context parameters
• KT-81074 KDoc: List rendering is broken

Analysis API. Providers and Caches

• KT-82449 K2 IDE Analysis Freezes During Gradle Sync (Recursive Module Dependency Computation in KotlinModuleDependentsProviderBase.computeTransitiveDependents)
• KT-82629 'collectDiagnostics' returns stale syntax error after editor fix
• KT-74907 Analysis API: Apply platform-based library module content restrictions consistently

Analysis API. Standalone

• KT-81107 AA: KtSourceModuleBuilder.sourceRoots doesn't works with symbolic links

Analysis API. Stubs and Decompilation

• KT-82792 Stub for KtValueArgumentList inside KtAnnotationEntry should be present if it is present in psi
• KT-82527 TypeClsStubBuilder.createFunctionTypeStub throws NullPointerException
• KT-82558 Deserialized DNN type should have a fully qualified Any
• KT-81928 KaArrayAnnotationValueImpl.values missing first element
• KT-82139 Support contracts for property accessors
• KT-82198 Support context parameters in contracts

Analysis API. Surface

New Features

• KT-82851 Property accessors should inherit KDoc from the parent property
• KT-63339 Analysis API: Provide a way to extract KDoc for symbols
• KT-79070 KaTypeProvider: add API to build a default type with star projections
• KT-66566 AA: api to create functional types
• KT-66043 KtTypeCreator doesn't provide a way for creating annotated types

Performance Improvements

• KT-83694 Provide psi-based implementation of KaDeclarationSymbol#isExternal
• KT-70868 KaSymbol: support PSI-only visibility and modality for the case without compiler plugins
• KT-81627 KaFirSymbolDeclarationOverridesProvider#processOverrides should process only relevant declarations

Fixes

• KT-83152 [Analysis API, KDoc] Make class name links on constructors point to the class
• KT-83695 Deprecate KaSymbolInformationProvider#{getter, setter}DeprecationStatus
• KT-82853 Add a convenience property for testing declarations for effective external-ness
• KT-83226 Support "Collection literals" in the Analysis API
• KT-83225 Support "@IntroduceAt" in the Analysis API
• KT-83222 Support "Improve use-site defaulting for annotations" in the Analysis API
• KT-83351 Rename KaSession context parameter from 's' in bridges to something nicer
• KT-83199 Clarify API around extension points
• KT-83074 Inner enum entry class has incorrect default visibility
• KT-82442 Add Ka prefix to org.jetbrains.kotlin.analysis.api.symbols.AdditionalKDocResolutionProvider
• KT-82443 Add Ka prefix to org.jetbrains.kotlin.analysis.api.symbols.DebugSymbolRenderer
• KT-82441 Add Ka prefix to org.jetbrains.kotlin.analysis.api.compile.CodeFragmentCapturedValue
• KT-82439 Add Ka prefix to org.jetbrains.kotlin.analysis.api.components.DebuggerExtension
• KT-82438 Add Ka prefix to org.jetbrains.kotlin.analysis.api.components.DefaultTypeClassIds
• KT-68577 asPsiType and mapTypeToJvmType: leading delimiter for class in a root package
• KT-81734 MIssing "ARGUMENT_TYPE_MISMATCH" caused by self-referential generic type
• KT-82856 Redesign KotlinReferenceProviderContributor to make it extensible
• KT-82615 Clarify KtReference#resolvesByNames contract
• KT-82534 No expected type for property accessor without body
• KT-82406 Add a test to ensure that all top-level classes in the Analysis API Surface have Ka prefix
• KT-78397 investigate if there is a need in Extra support for the "various little features in contracts"
• KT-74009 Analysis API: Expose "isOverloadable" check for callable symbols similar to "OverloadChecker.isOverloadable"
• KT-78399 Check return value - check how we see from Java(+Stub) we see “annotated” signatures
• KT-80357 [Analysis API] KaType.enhancedType doesn't enhance type parameters
• KT-73659 Analysis API: The name of KaType.enhancedType is too general
• KT-80545 [Analysis API] Deprecate KaFunctionType.arity
• KT-77708 K2 Mode: Potentially redundant smart cast highlighing when passing smartcasted expressions as arguments
• KT-81264 K2 AA: KaValueParameterSymbol.hasDefaultValue is false for overriding or actual functions
• KT-81166 Forbid the usage of KaSessionComponent implementation types directly
• KT-74801 Analysis API: Publish/subscribe to modification events with a single message bus topic

Backend. Native. Debug

• KT-81741 Native: stepping into data class hashCode in lldb goes to line 1

Backend. Wasm

New Features

• KT-81485 [Wasm] DebuggerCustomFormatters generation support for single module mode
• KT-81483 [Wasm] Typescript generation support for single module mode
• KT-81484 [Wasm] Dwarf generation support for single module mode

Performance Improvements

• KT-83839 K/Wasm: CMP. Load time on Safari significantly increased with Kotlin = 2.3.20-Beta1
• KT-81524 Unnecessary Any-JsAny conversions are generated for external instanceofs

Fixes

• KT-82732 K/Wasm runtime crash when using fun reference: convertKotlinClosureToJsClosure
• KT-82649 K/Wasm: Rewrite StringBuilder to use JsString
• KT-73240 K/Wasm: consider using JS String Builtins proposal in String implementation for wasm-js target
• KT-83995 K/Wasm: 2.3.0 -> 2.3.20-Beta1 degradation in arrow tests
• KT-82309 K/Wasm: refactor _initialize function
• KT-70075 Wasm: "OutOfMemoryError: GC overhead limit exceeded" during tests
• KT-83046 K/Wasm: don't use StringBuilder implicitly for string concatenations
• KT-82645 K/Wasm: wasmJs use js "String" for number2String conversion
• KT-79937 K/Wasm: support kotlin.js.nativeInvoke annotation
• KT-67461 Use new lowering phase creation API in Wasm backend
• KT-83664 Wasm: Colon and space are not sanitized in output file names
• KT-65779 JsExport declaration name clash
• KT-82202 [Wasm] SourceMap generation support for single module mode
• KT-82162 [Wasm] Run single module tests with standalone vm's
• KT-81325 [Wasm] Remove string pool initialiser dependent code
• KT-73238 K/Wasm: stop using linear memory inside our code
• KT-83025 Wasm: Compose application is not loading
• KT-73239 K/Wasm: use JS String Builtins proposal to transfer strings to and from JS
• KT-83194 K/Wasm: create WasmIR test infrastructure
• KT-65234 K/Wasm Ensure that fp operations are aligned with other b-ends
• KT-81856 K/JS/Wasm interop: external instanceofs do not link in singleModule mode
• KT-81610 [Wasm] Add CLI test for performance metrics for klibs->binary scenario
• KT-81550 Incorrect generation of .wat files
• KT-71533 K/Wasm + K2: no error on KClass::qualifiedName usages

Compiler

New Features

• KT-75736 Enable reading/writing annotations in metadata on JVM by default
• KT-79330 Implement the first version of inference for Collection Literals
• KT-83401 Collection literals: support different types of expected types for CL
• KT-55548 JSR-305: Overload resolution ambiguity: Platform Types vs Kotlin Types
• KT-74860 Support Unit coercion (incl. fun refs) in unused return value checker
• KT-13968 Support vertx nullable annotation
• KT-79656 Use org.jetbrains.annotations.UnmodifiableView and/or org.jetbrains.annotations.Unmodifiable to infer read-only types for Java entities
• KT-81684 Implement explicit passing of context arguments using named syntax [TEST_ONLY]
• KT-80492 Checkers for operator of
• KT-82638 Collection literals: resolve to factory functions for standard library classes
• KT-82467 Improve binary and JVM compatibility by generating bridges for abstract interface methods
• KT-82655 Bridges generated for non-fake overrides shall include annotations from target methods
• KT-74223 Move Kotlin/Native TestProcessor phase to the first phase
• KT-27090 Support contracts in getter and setter for top-level extension properties
• KT-74809 Support unnamed local variables
• KT-45683 Allow generics in contract type assertions

Performance Improvements

• KT-81974 Do not eagerly initialize reflection for KProperty objects for delegated properties
• KT-83697 Native: increased bitcode produced with enabled safe casts
• KT-83036 Native: too many casts emitted with -Xgeneric-safe-casts=true
• KT-80061 Compiler (or IDEA) hangs due to importing large Kotlin reflect functions (e.g. KFunction999999999)
• KT-68592 Investigate performance implications of enabling -Xjvm-default for ir.tree module
• KT-73687 Inefficient KtCommonFile#getFileAnnotationList
• KT-71673 Consider making EnhancementSymbolsCache. enhancedFunctions using simple cache

Fixes

• KT-84773 Annotations not persisted in IR for internal external functions
• KT-78783 K2: absence of warning for KTLC-284 migration
• KT-81553 INITIALIZER_TYPE_MISMATCH and ASSIGNMENT_TYPE_MISMATCH is reported on the entire initializer
• KT-83395 Kotlin/Native 2.3.0 iOS release framework fails with Invalid LLVM module (PHI node type mismatch)
• KT-84620 Incorrect optimization of property delegation
• KT-81567 Add a use-site warning if a @DslMarker-marked annotation is used on entities where it is a no-op
• KT-81700 flaky overload resolution behaviors (false-positive errors, different final candidates, compile-time failures)
• KT-83372 compileDebugKotlinAndroid hangs in 2.3.0 with SQLDelight
• KT-82579 Update specificity rule for context parameters
• KT-83590 Some explicit backing fields must still be considered private-to-this
• KT-83849 False-positive NULLABILITY_MISMATCH_BASED_ON_JAVA_ANNOTATIONS for Optional.orElse(null) call
• KT-84192 "Member overrides different '@Throws' filter from" caused by overriding in different module
• KT-72994 K2: Remove resolution to context receivers
• KT-80247 No diagnostic on unresolved type annotation from a dependency in an inferred type
• KT-78730 Move more LLVM-agnostic code to compiler/ir/backend.native or compiler/ir/backend.common
• KT-74051 Add a Continuation for tail-call suspend functions
• KT-83984 Data races around kotlinx.serialization plugin protobuf extensions registration
• KT-83317 ClassCastException: with cast kotlin.UInt to java.lang.Number when defining constant
• KT-83031 K2: unstable resolution of EnhancedNullability from type-use NotNull in presence of unused code
• KT-83824 Delegated property in Gradle DSL fails to compile
• KT-83657 [K/N] Pre-codegen inline produces invalid bitcode
• KT-81555 Kotlin scripts: top-level name-based destructuring with _ = prop fails with “exception while generating code”
• KT-83314 JSpecify @NullMarked changes Java equals(Object) to equals(Any?) causing override conflict in Kotlin 2.3
• KT-83282 JvmExposeBoxed: Duplicate annotation interface kotlin.coroutines.jvm.internal.DebugMetadata in class %class%$1 for suspend inline class value
• KT-78443 Refactor session component initialization for multi-target compilation
• KT-83427 Arguments of plugin-generated annotations are serialized incorrectly
• KT-83538 OPERATOR_RENAMED_ON_IMPORT is not reported for 'provideDelegate' operator
• KT-83537 OPERATOR_RENAMED_ON_IMPORT is not reported for 'of' operator
• KT-82721 Inconsistent explicit backing fields behavior
• KT-83589 Explicit backing fields don't likely work with intersection overrides
• KT-81951 K2: Another false positive "Assigned value is never read" in composable function
• KT-83588 Explicit backing field is falsely accessible from a subclass via a substitution override
• KT-82849 Collection literals (minor): collection literal should only be resolved to operator
• KT-83363 VerifyError: "Bad type on operand stack" on multi-line suspending call with default parameter value since API version 2.4
• KT-83570 K2: Resolve problematic IR when referencing Kotlin const from annotation in Java
• KT-83362 Starting from 2.3 DefaultImpls bridge functions deprecated with the level HIDDEN are no longer synthetic
• KT-9182 Java interoperability: Overload resolution ambiguity on Java's @NotNull and primitives
• KT-83633 Forbid inline functional context parameters in inline functions
• KT-83449 compile-time IR failure on smart cast information leaking from capturing closure
• KT-82375 Add ATOMIC_REF_WITHOUT_CONSISTENT_IDENTITY warning for any argument without consistent identity
• KT-82524 Access to a companion that requires opt-in is possible without opt-in
• KT-83367 VolatileFieldsLowering may emit wrong parameter types for atomic intrinsic calls
• KT-83382 K2: Unreachable method exit breaks MUST_BE_INITIALIZED checks for succeeding value declarations
• KT-82211 False positive SENSELESS_NULL_IN_WHEN with nullable var
• KT-83157 ExplicitBackingFields: "Property with explicit backing field should be final" in 2.3.0
• KT-83269 K2: Wrong types in IR for explicit backing fields
• KT-68606 Argument type mismatch, despite being from the same star-projected type
• KT-83324 Native: problem with loops handling in types computation pass
• KT-83241 K2: "NoSuchElementException: List is empty" with top-level destructuring declaration and lambda initializer
• KT-82277 Misleading Inapplicable candidate(s): fun <K> WHEN_CALL(vararg branches: K): K when a when expression branch contains an unresolved reference
• KT-80839 Get rid of an obsolete -Xcompile-builtins-as-part-of-stdlib flag once previous changes are bootstrapped
• KT-82900 Language Feature EnhancedBridgesGeneration
• KT-82651 Do not generate self-recursive bridges in JVM backend
• KT-5486 Better errors for integers with leading zero
• KT-83185 Kotlin repeatable annotations are incorrectly deserialized from bytecode
• KT-82863 @NoInfer regression since 2.2.20
• KT-82376 Header mode: Index out of bounds when generating bodies of data class
• KT-82311 Header mode: Error expression when assigning function declaration to a property
• KT-82408 Header mode: Java files are not compiled successfully
• KT-82378 Header mode: Sequence contains no element matching the predicate
• KT-82407 Header mode: Backend Internal error: Exception during IR lowering
• KT-81763 Incorrect comparison result when using elvis ?: with nullable Long values
• KT-83153 Properly ignore contract statements in the Return Value Checker
• KT-83076 Don't report WRONG_JS_INTEROP_TYPE on expect types during metadata compilation
• KT-78589 "Class does not have member field" caused by delegation from a Java to Kotlin class
• KT-82640 K2: CCE on green code
• KT-82684 "Don't know how to compile annotation value ERROR_EXPR" on incorrect array literal in annotation default arguments
• KT-81948 K2: ClassCastException: "java.lang.String cannot be cast to java.lang.Void" when calling @Nullable Java function
• KT-82788 false-positive duplicate JVM class name error in IJ monorepo
• KT-82841 "kotlin.NoWhenBranchMatchedException" in when with !is check & non-sealed class in the middle of hierarchy
• KT-82844 "when" with no branches does not evaluate subject (side effects ignored)
• KT-81625 Incorrect empty parameters parsing (comma is highlighted in red)
• KT-81193 K2: SOE from AbstractTypeApproximator.approximateToSuperType with local enum class
• KT-65059 Stack overflow when typechecking an Elvis expression with deeply generic values
• KT-82555 @Deprecated(HIDDEN)` objects not skipped when resolving qualifiers
• KT-82737 Leaked type variable in diagnostic when top-level lambda with uninferred type parameter has non-functional expected type
• KT-78019 Change K1 API deprecation level from Warning to Error
• KT-82683 K2: FIR2IR: compile-time JVM codegen failure on an argument of function subtype for a KSuspendFunction parameter
• KT-82671 Do not report ignorability mismatch on override/actualization if the function returns Unit type
• KT-82506 Misleading compilation warning: "This class is not recommended for use in Kotlin. Use 'java.util.Map' instead"
• KT-52498 Test privateSuperType.kt is failing with caches enabled
• KT-82336 Header mode: Cannot infer argument for type parameter T
• KT-69326 Inference chooses controversial order to fix variables
• KT-82545 Handle data class with extra components in migration warning for name-based destructuring
• KT-82303 Improve UNSUPPORTED_FEATURE message when compiler argument has a parameter
• KT-81866 K2: False positive ILLEGAL_RESTRICTED_SUSPENDING_FUNCTION_CALL caused by smart-casted @RestrictsSuspension receiver
• KT-13412 Improve error message on callable reference with expression of nullable type
• KT-82466 KotlinIllegalArgumentExceptionWithAttachment when return is used in explicit delegation expression
• KT-82454 Local types aren't approximated in public declaration types
• KT-82487 False positive REDUNDANT_VISIBILITY_MODIFIER inside private class
• KT-82369 [K2 REPL] Crash in the serialization plugin backend with "unable to transform declaration"
• KT-82243 Usage of nested type aliases is forbidden despite the feature flag
• KT-62900 K2: Expected expression to be resolved during Fir2Ir
• KT-81941 IllegalArgumentException: class org.jetbrains.kotlin.psi.KtValueArgument is not a subtype of class org.jetbrains.kotlin.psi.KtExpression for factory POSITIONED_VALUE_ARGUMENT_FOR_JAVA_ANNOTATION
• KT-80741 Fix rendering of inner classes with generic outer classes
• KT-82331 Do not propagate context parameters from classes to constructors
• KT-77276 K2: Wrong scope for annotation arguments for the parameters of a secondary constructor header
• KT-77275 Inconsistency between scopes for primary/secondary constructor headers
• KT-15152 Improve error message for unresolved reference for delegation specifier and primary constructor call
• KT-81498 Make Kotlin/Native stdlib in distribution reproducible
• KT-81408 Allow local-variable-target annotations on destructuring declarations
• KT-82012 Annotations without parentheses on full form of name-based destructuring don't work
• KT-81915 Exception when analysing 'when' expression with annotated expression as a subject
• KT-78364 Static methods are not generated for companion object JvmStatic property accessors with JvmExposeBoxed
• KT-81838 Prohibit usage of nested type aliases (from lib) for sources with LV < 2.3
• KT-81357 Forbid compilation of code with explicit root_ide_package in CLI mode
• KT-73138 K2: "Assignment type mismatch" when class name is underscore_
• KT-82169 Add quotes to message of WRONG_NUMBER_OF_TYPE_ARGUMENTS
• KT-78386 JvmExposeBoxed (with no name) + JvmOverloads + JvmName produces ambiguity
• KT-78358 Propagated JvmExposeBoxed annotation doesn't copy JvmName argument
• KT-81699 Move native klib compilation to a separate module
• KT-81692 Decouple compilation of Native klib from the Native backend
• KT-80673 Consider forbidding/minimizing usages of ClassId.isLocal and CallableId.isLocal
• KT-81376 False negative UNEXPECTED_TRAILING_LAMBDA_ON_A_NEW_LINE & bad positioning
• KT-81946 false-positive JAVA_CLASS_ON_COMPANION in case of an explicit companion reference
• KT-74461 K2: Render function types nicely
• KT-81875 NCDFE: kotlinx/coroutines/internal/intellij/IntellijCoroutines at :compiler:multiplatform-parsing:jvmTest
• KT-49722 Report NOT_YET_SUPPORTED_IN_INLINE for inherited default parameters with inline function
• KT-81913 Inapplicable candidate when vararg-adaption for callable reference might be used (array parameter)
• KT-81841 Inapplicable candidate when vararg-adaption for callable reference might be used (generic parameter)
• KT-39697 "Cannot infer type parameter" in map with java static or global method reference
• KT-81896 Improve RedundantCallOfConversionMethod inspection for @UnsafeNumber annotated typealiases
• KT-66413 Incorrect line mapping in suspendable code before suspend call without parameters
• KT-80525 Update IntelliJ SDK dependency to 251.27812.49
• KT-81808 Setting hasDefaultValue = true in irValueParameter() crashes the compiler
• KT-78927 False positive 'USELESS_JVM_EXPOSE_BOXED'
• KT-81703 Drop obsolete K1 frontend code from Kotlin/Native
• KT-81698 DecoupleSpecialBackendChecksTraversal from Native backend
• KT-81687 Different LightTree and PSI outputs when annotated class-like declaration is used as an expression
• KT-81302 False positive: Type Mismatch caused by context parameters, lambdas, and generics
• KT-81584 IAE "Collection contains more than one matching element" in FirElementSerializer on contextual property with same name as primary value class property
• KT-77237 JvmExposeBoxed breaks compilation with a secondary constructor with value class
• KT-81262 False positive: Access declaration type exposure: during access to public function class from internal inline declaration
• KT-80112 Kotlin Debugger: “Cannot find local variable” on evaluating default lambda inside inline function
• KT-76806 K2: AIOOBE in FirEqualityCompatibilityChecker
• KT-81693 Introduce lightweight versions of KonanConfig and PhaseContext
• KT-72446 K/N: inline function's default values aren't lowered with caches
• KT-81521 Anonymous function in context parameters breaks parser
• KT-80853 Class reference in context parameters breaks parser
• KT-81441 Missing type checks when class has deeply generic supertype
• KT-79116 Wrong parameter arguments mapping (compiler skips empty arguments)
• KT-81422 False negative in full-form name-based destructuring: annotations before val/var not rejected
• KT-80652 K2: USELESS_IS_CHECK is not detected in when
• KT-80049 Mangle ERROR_TYPEs in diagnostics reported to user
• KT-73786 Evaluator: cannot evaluate inline methods with reified parameter
• KT-75828 Store backing field/delegate annotations and extension receiver annotations in metadata
• KT-74572 Context parameters: contracts don't work with context parameters
• KT-42824 FIR: false INAPPLICABLE_CANDIDATE when using in variance on a Java class

Compose compiler

• b/481953005, b/481769383 Cache stability inference results during session
• b/481735904 Fix Compose codegen crash in inline function
• b/479646393 Add groups to inline functions with two or more inline parameters
• b/458234821 Disable Compose K1 tests on CI
• b/456948687 Force resolution of declarations when looking up SAM functions in FIR
• b/445426829 Add a diagnostic for key call with no arguments

IR. Actualizer

• KT-82418 KMP Separate Compilation: NPE caused by actualization of NsCalendar.getEra
• KT-82313 ACTUAL_ANNOTATION_CONFLICTING_DEFAULT_ARGUMENT_VALUE checks throw conflicting values in expected and actual annotations

IR. Inlining

Fixes

• KT-82017 [Inliner] Inline function overrides abstract method with default value
• KT-80814 [IR Inliner] Space: jsBrowserProductionWebpack task failed with HookWebpackError
• KT-83280 Split LibrarySpecialCompatibilityChecksTest into pure JS and pure Wasm tests
• KT-81766 K/N: Recursive inline expect/actual causes StackOverflowError
• KT-80953 [Inliner] Eliminate excessive IMPLICIT_CAST after IR Inliner on 2nd stage.
• KT-79899 [IR Inliner] Split single-module tests having inline fun into files
• KT-83148 KLIB inliner: Make both "inliner" language features to require Api Version = 2.3
• KT-80791 classFunctionsAndFieldsWithCrossModuleInliner fails per-file with cross-module inliner
• KT-80696 Can not get instance of singleton 'Obj': No class found for symbol
• KT-82065 IR inliner: Inline function's default value argument may get wrong offsets in a temporary variable
• KT-81753 Review diagnosticReporters usage in pre-serialization lowerings
• KT-80793 Test friendDependencyWithCrossModuleInliner fails per-file with cross-module inliner
• KT-80698 [IC][WASM] Mismatched file stats
• KT-80697 [IC][JS per file] Mismatched rebuilt modules
• KT-80660 [Inliner] Bodyless functions should not be inlined at 1st compilation stage
• KT-79064 Try to get rid of TypeOfPostProcessor

IR. Interpreter

• KT-82161 Enable Enum.name and KCallable.name to constant evaluation
• KT-80646 Enable unsigned conversion functions when bootstrapped compiler is available

IR. Tree

• KT-82765 Kotlin/Native: Internal compiler error when building DFG
• KT-82829 IR deserializer: Don't deserialize any cinterop fake overrides from Klibs
• KT-83236 PeopleInSpace_mpp compilation error: The symbol table has been sealed
• KT-81154 [IrValidator] Fine-tune IrVisibilityChecker on 2nd stage
• KT-80243 Support Name Based Destructuring in loop with withIndex()
• KT-79436 KLIB stdlib symbols loading: Drop all functions from SymbolFinder except for loading the whole collection of (potentially unbound) symbols by name
• KT-79435 KLIB stdlib symbols loading: Load symbols and and filter/map them lazily in BuiltinSymbolsBase hierarchy when accessed by IR
• KT-69082 Migrate maps of IR elements to IR attributes
• KT-67457 Introduce a way to simplify IR lowering phase creation

JVM. Reflection

New Features

• KT-22265 Support for inherited annotations

Performance Improvements

• KT-84600 Performance regression around Kotlin properties JVM reflection during instantiation

Fixes

• KT-83608 Kotlin-reflect: "Unknown origin of public abstract operator fun invoke(p1: P1, p2: P2): R"
• KT-57357 Reflection: "KotlinReflectionInternalError" when using callBy on constructor that has inline class parameter with nullable value
• KT-83361 "KotlinReflectionInternalError: Type parameter not found: 0" on super types with Kotlin 2.3.0
• KT-42199 "KotlinReflectionInternalError: Unknown origin of public abstract operator fun invoke" on function reference to FunctionN.invoke
• KT-81024 Reflection: New KType implementation fails on arguments comparison for a Nothing type parameter
• KT-83067 Reflection: IAE "argument type mismatch" on callBy with vararg of generic type parameter with primitive upper bound
• KT-82699 Reflection: incorrect behavior of KFunction.isExternal for Java native methods
• KT-82350 Reflection: incorrect behavior of KType.javaType on a type obtained from KType.withNullability
• KT-29203 KType.javaType always returns void class for local delegated property
• KT-81899 Reflection: incorrect javaType for local delegated property setter return type
• KT-82093 Reflection: IAE from defaultType for inner class of generic class
• KT-77312 KotlinReflectionInternalError: "Container of deserialized member is not resolved" on computing type parameter captured in a local delegated property
• KT-82316 Reflection: type parameters of top-level declarations behave incorrectly
• KT-81987 Reflection: error when calling function in inline class with inherited default value
• KT-81870 Reflection: Error when calling function with default parameters and extension receiver
• KT-81880 Reflection: Error when calling function with default & context parameters
• KT-81907 Reflection: incorrect result when calling function with default values and context parameters
• KT-81859 Reflection: do not use descriptors in ValueClassAwareCaller
• KT-81854 Reflection: incorrect type for instance receiver of inner class constructor
• KT-81855 Reflection: IAE "object is not an instance of declaring class" on function with context and extension receiver of inline class
• KT-81843 Reflection: NPE on accessing property accessor returnType for Java field
• KT-81588 Reflection: KotlinReflectionInternalError "Inconsistent number of parameters" on calling contextual declaration with value class type in the signature
• KT-81111 Reflection: suspend function types are loaded incorrectly by the new implementation
• KT-81206 Reflection: non-substituted Function type in suspend function supertypes
• KT-81804 Reflection: remove support for multi-field value classes
• KT-81664 Reflection: IAE "argument type mismatch" on calling member extension with value class in the signature

JavaScript

New Features

• KT-83454 K/JS: Support ES6 classes in js() calls
• KT-83455 K/JS: Support ES6 default function arguments in js() calls
• KT-83453 K/JS: Support ES6 concise methods in js() calls
• KT-83457 K/JS: Support ES6 spread operators in js() calls
• KT-83456 K/JS: Support ES6 rest function parameters in js() calls
• KT-54504 K/JS: Support ECMAScript tagged string templates
• KT-82327 KJS: Export parameter names of function types if present in .d.ts files
• KT-82371 KJS: Generate more concrete TypeScript for members of an uninhabited enum

Performance Improvements

• KT-16379 KotlinJs - ArrayList get is now slow

Fixes

• KT-64951 Kotlin-Multiplatform does not allow JSExport of expect
• KT-83528 K/JS: Array holes in array literals are ignored in the new js() parser
• KT-84134 KJS/CMP: "IrLinkageError: Function 'get' can not be called: No function found for symbol"
• KT-65802 How to implement Interfaces in Javascript/Typescript?
• KT-83830 Relocate org.antlr.v4 to an internal package
• KT-83572 KJS/Wasm: Cannot access @JsModule-declared class from non-modular project
• KT-83930 Kotlin/JS: JsStatic on property of interface companion generates incorrect d.ts
• KT-70986 Add Swc into the compilation pipeline of Kotlin/JS
• KT-78742 Investigate the usage of the ANTLR-generated parser for the js function
• KT-60554 KJS: rethink JS_*_NAME_CLASH diagnostics
• KT-82552 KJS: "Non-abstract class does not implement inherited abstract member from class" errors in generated .d.ts
• KT-82652 KJS: Exported abstract inner classes can be constructed from TypeScript
• KT-82542 KJS: Inner class can be constructed from TypeScript without passing an outer instance
• KT-82499 KJS: Omit parameters in private constructors in .d.ts files
• KT-41082 KJS: 'Reflection is not supported on JavaScript target, so you won't be able to read this annotation in runtime' warning is inconvenient and misleading
• KT-82279 KJS: DCE removes external members overrides without reason
• KT-52800 KJS / IR: sealed interface with nested data classes not accessible
• KT-67460 Use new lowering phase creation API in JS backend
• KT-82667 Kotlin/JS: ESM TypeScript definitions for exported nested Enums do not compile
• KT-82553 KJS: Incorrect .d.ts generated for generic inner classes
• KT-82263 Implement exporting top-level properties in Analysis API-based TypeScript Export
• KT-82362 KJS: Incorrect types generated in .d.ts for JsName-annotated enum entry
• KT-82262 Implement exporting top-level functions in Analysis API-based TypeScript Export
• KT-82144 K/JS: 'meta' identifier usage in js() inline calls prevents expression from parsing
• KT-82149 K/JS: new calls without arguments produce exceptions in js() inline calls
• KT-81730 Optimize suspend functions compilations via JS generators
• KT-79243 [JS] Drop K1-specific tests, testrunners and test directives

Klibs

New Features

• KT-83101 Implement experimental KLib ABI dump parser

Fixes

• KT-82586 Export in previous version (JS, Wasm): adjust the checker for incompatible Kotlin stdlib/compiler pairs
• KT-84273 [Klib] Added IrOffsetsChecker broke backward klib compatibility
• KT-80910 [Klib] Ensure serialized source coordinates are correct
• KT-81955 [JS] Support testing of forward compatibility with export in previous version
• KT-81957 [JS] Create a common Gradle test task
• KT-82736 False positive IR_PRIVATE_CALLABLE_REFERENCED_BY_NON_PRIVATE_INLINE_FUNCTION_ERROR on referenece to local declaration
• KT-82758 [PL] Change the behavior of getting name of removed property
• KT-81470 Simplify inline function deserialization after the bootstrap update
• KT-81466 Enable KlibAnnotationsInMetadata by default in LV 2.5
• KT-82208 K/Wasm: allow using newer stdlib with older compiler
• KT-83328 kotlin-wasm-benchmarks: Compilation errors due to missing KLIB dependencies
• KT-83071 Failure on Native Nightly
• KT-78365 [PL] Change the behavior of getting name of removed function
• KT-81977 Klib compatibility tests: Implement sanity checks
• KT-81410 Klib metadata: migrate to using the common annotations instead of klib-specific extensions in kotlinx-metadata-klib
• KT-82577 Don't use KLIB resolver in the KLIB tool
• KT-82213 IR linker doesn't complain when a private value class constructor is used from another module
• KT-81003 KLIBs: Eliminate excessive implicit casts in common prefix on the 1st stage
• KT-81670 K/N: Many Section still use none cacheable zip when Xklib-zip-file-accessor-cache-limit flag set
• KT-81954 [JS] All forward compatibility tests fail
• KT-81709 [KLIB Reproducibility] KLIB zip file generation is non-deterministic due to unsorted file system traversal
• KT-81474 [Tests][Klibs] Migrate Klib evolution tests to PL tests engine

Language Design

• KT-83009 Exposing of non-exportable API from interfaces
• KT-73502 Context parameters: it is not possible to declare local function with a context

Libraries

New Features

• KT-81997 Method to create a detached copy of a Map entry
• KT-79093 Expose FirResolvedStatus.hasMustUseReturnValue in kotlin-metadata

Performance Improvements

• KT-75801 Optimize Array to list conversion using array copy instead of a loop
• KT-82038 K/N: iterating over Array.asList is slower compared to ArrayList

Fixes

• KT-78115 Investigate the current situation with 22 kotlin.context standard library overloads
• KT-82363 Add assertIs to the list of ignorable functions
• KT-80666 K/N and K/Wasm: Regex: unassigned category is excluded from other chars
• KT-80665 K/N and K/Wasm: Regex: unicode category Symbol matches some punctuation marks
• KT-78089 K/N: Regex: Quantified groups matching is causing a stack overflow
• KT-82783 HashMap (K/N, Wasm), MapBuilder (all targets) duplicate keys
• KT-52400 Deprecate