org.jetbrains.kotlin:analysis-api-test-framework

Changelog

Backend. Wasm

• KT-87066 K/Wasm: Not all files are presented in compiler output directory with multimodule-closed-world and incremental compilation

Compiler

• KT-86939 JVM: IllegalStateException "No value for annotation parameter" when using const val in nested Java annotation array argument
• KT-83766 K2: Wrong sourcePsi is set for SymbolPsiLiteral in SLC for annotation arguments referencing a const val
• KT-86728 Reified type inference: expected type not propagated into inline call inside lambda with elvis operator

Compose Compiler

• b/522127447 Compose Compiler 2.4: classes previously inferred stable now reported runtime/Uncertain

Klibs

• KT-86501 Native: IrTypeAliasSymbolImpl is already bound. Signature: kotlinx.datetime/Instant|null[0] on iosSimulatorArm64

Tools. CLI

• KT-86930 Introduce kotlinr in the Kotlin distribution

Tools. Gradle. BCV

• KT-87223 Gradle, BCV: open version range in kotlinAbiValidationCompatClasspath causes kotlin-build-tools-impl to resolve to 2.4.20-Beta1 instead of 2.4.0

Tools. Gradle. JS

• KT-87304 jsBrowserTest fails with "exited with errors (exit code: 1)"
• KT-86057 kotlinUpgradeYarnLock skips lock file regeneration when kotlinNpmInstall is up-to-date, causing kotlinStoreYarnLock to fail

Tools. Gradle. Multiplatform

• KT-87084 False positive warning for JS and Wasm compilations when CRI is enabled

Tools. Scripts

• KT-87076 @file:CompilerOptions("-jvm-target", ...) ignored in .main.kts scripts in Kotlin 2.4.0, falling back to JVM target 1.8
• KT-86352 K2 scripting: FirResolvedTypeRef exception when resolving extension functions from imported scripts

Changelog

Backend. Wasm

• KT-87066 K/Wasm: Not all files are presented in compiler output directory with multimodule-closed-world and incremental compilation

Tools. Gradle. BCV

• KT-87223 Gradle, BCV: open version range in kotlinAbiValidationCompatClasspath causes kotlin-build-tools-impl to resolve to 2.4.20-Beta1 instead of 2.4.0

Tools. Gradle. JS

• KT-87304 jsBrowserTest fails with "exited with errors (exit code: 1)"

Changelog

Compiler

• KT-86939 JVM: IllegalStateException "No value for annotation parameter" when using const val in nested Java annotation array argument
• KT-83766 K2: Wrong sourcePsi is set for SymbolPsiLiteral in SLC for annotation arguments referencing a const val
• KT-86728 Reified type inference: expected type not propagated into inline call inside lambda with elvis operator

Compose compiler

• b/522127447 Fixed a bug that was making the stability of pre-cast types be used in certain skipping checks instead of the stability of post-cast types

Klibs

• KT-86501 Native: IrTypeAliasSymbolImpl is already bound. Signature: kotlinx.datetime/Instant|null[0] on iosSimulatorArm64

Tools. CLI

• KT-86930 Introduce kotlinr in the Kotlin distribution

Tools. Gradle. JS

• KT-86057 kotlinUpgradeYarnLock skips lock file regeneration when kotlinNpmInstall is up-to-date, causing kotlinStoreYarnLock to fail

Tools. Gradle. Multiplatform

• KT-87084 False positive warning for JS and Wasm compilations when CRI is enabled

Tools. Scripts

• KT-87076 @file:CompilerOptions("-jvm-target", ...) ignored in .main.kts scripts in Kotlin 2.4.0, falling back to JVM target 1.8
• KT-86352 K2 scripting: FirResolvedTypeRef exception when resolving extension functions from imported scripts

Changelog

Analysis API

• KT-83867 OVERLOAD_RESOLUTION_AMBIGUITY false positive with assertEquals in IJ repo
• KT-83723 [Analysis API] Enable experimental KDoc resolver by default
• KT-83388 Analysis API: properly support KMP in KotlinPackageProvider
• KT-65683 Analysis API: Dangling file session creation causes a computeIfAbsent contract violation

Analysis API. Code Compilation

• KT-78946 Evaluation of variable with local class in type parameter leads to InventNamesForLocalClasses exception

Analysis API. FIR

• KT-68260 K2 AA: InvalidFirElementTypeException “For CALLABLE_REFERENCE_EXPRESSION with text ::lam1, unexpected element of type: no element found” with illegal callable reference call
• KT-70896 AA: False positive deprecation warning with override of built-in method in JDK mapped class
• KT-84711 K2 IDE sometimes loses FIR plugin-generated declarations after file changes
• KT-84625 Analysis API: collectDesignationPath fails for nested classes inside plugin-generated top-level classes
• KT-84596 Improve K2 Jooq completion performance
• KT-84525 KaValueParameterSymbol#getHasSynthesizedName returns false for FirDeclarationOrigin.SubstitutionOverride.DeclarationSite
• KT-83546 Kotlin analysis reach ClsCustomNavigationPolicy
• KT-84259 Move CommonDefaultImportsProvider to the frontend independent module
• KT-82945 Analysis API: KotlinIllegalArgumentExceptionWithAttachments: Expected FirResolvedTypeRef with ConeKotlinType but was FirUserTypeRefImpl
• KT-71135 AA: exception from sealed inheritors checker when analyzeCopy

Analysis API. Infrastructure

Fixes

• KT-83905 Analysis API: Improve UX with test data
• KT-84913 Extract compiler classes used by the PSI & Analysis API to a separate module
• KT-64986 Analysis API: Implement Analysis API tests for different KMP Platforms
• KT-84776 The test data manager misses the redundancy check in the update mode
• KT-84962 The test data manager misses -ea flag
• KT-84388 Preserve the EOF status in the test data manager to avoid extra changes
• KT-84362 Analysis API tests produce many warnings due to "not yet loaded registry"
• KT-84279 Test Data Manager fails on a clean build
• KT-83913 Exclude compiler-based Analysis API tests from Git tracking
• KT-80379 Extract per-module test generators for AA tests
• KT-84120 Move CLI modules out of kotlin-compiler-fe10-for-ide
• KT-83200 Track external dependencies of the Analysis API modules

Analysis API. Light Classes

• KT-82434 Light classes should prefer enum entries to properties
• KT-84200 SLC: return type is not boxed for delegated methods with generic original method
• KT-72451 "CCE: class PsiPrimitiveType cannot be cast to class PsiClassType" with same-named enum class and typealias

Analysis API. PSI

• KT-84715 removeModifier doesn't delete whitespaces around the removed modifier
• KT-84564 KtEnumEntry.delete deletes semicolon
• KT-84781 Use computed properties in KotlinElementTypeProviderImpl
• KT-83846 Set up guidelines for PSI
• KT-84135 Deprecate KtSelfType

Analysis API. Providers and Caches

• KT-82731 Analysis API: Limit granular tree change processing to a few files
• KT-79234 Analysis API: Usage of asMap() on Caffeine caches bypasses stats counters
• KT-74090 Analysis API: Support dumb mode (restricted analysis)

Analysis API. Standalone

• KT-83801 Nested typealiases are not correctly indexed in standalone mode

Analysis API. Stubs and Decompilation

• KT-85371 StackOverflowError from LLKotlinStubBasedLibrarySymbolProvider and StubBasedClassDeserialization
• KT-83935 Support KDoc loading in decompiled stubs

Analysis API. Surface

New Features

• KT-85239 Streaming version of collectDiagnostics()
• KT-82519 Automatically recognize the appropriate analysis mode for in-memory file copies based on their content
• KT-73534 SAM method API
• KT-82993 Support explicit backing fields in the Analysis API

Fixes

• KT-79186 KtCompletionExtensionCandidateChecker does not work for extensions when using callable references of a type
• KT-83759 Analysis API: Mark platform interface APIs with @KaPlatformInterface
• KT-83921 Extend KaKDocProvider to read Kdoc from KLIB metadata
• KT-77426 KaFirCompilerFacility uses an arbitrary JVM counterpart for common sources
• KT-84737 KaCallableSymbol#directlyOverriddenSymbols doesn't work for java overrides of kotlin properties
• KT-84621 Migrate symbol tests to ManagedTest properly
• KT-80575 KaFirJavaInteroperabilityComponent#getJavaGetterName should not throw exception on incomplete code
• KT-84397 KtDefaultAnnotationArgumentReference should return only results with value name
• KT-84804 buildSubstitutor does not work correctly with Java type parameters
• KT-84389 Cover references with ABI and documentation checks
• KT-57042 K2, Analysis API: KaJavaInteroperabilityComponent#callableSymbol returns null for a Java getter implementing Kotlin property
• KT-80856 Analysis API: analysisContextModule incorrectly determines the module of an original file when used for dangling file context assignment
• KT-84363 AA, isUsedAsExpression: Unhandled Non-KtExpression parent of KtExpression: class org.jetbrains.kotlin.psi.KtContractEffect
• KT-70476 Analysis API: "KtDefaultAnnotationArgumentReference.resolveToSymbols" does not work in FIR implementation
• KT-68499 Split KtDefaultAnnotationArgumentReference on K1 and K2 implementation
• KT-70521 Analysis API: Impossible to distinguish between 'iterator' operator calls dispatched with imports from objects
• KT-77669 Context arguments are missed on implicit invoke calls
• KT-77670 resolveToCall: extensionReceiver is incorrectly chosed due to a conflict with context parameters for an implicit invoke call
• KT-68633 K2 AA: IAE "Expected class KaClassSymbol instead of class KaFirEnumEntrySymbol" with enum entry initializer
• KT-83777 Analysis API: The resolution scope of a context module accepts elements from associated dangling files
• KT-82571 No expected type for overridden property without explicit type
• KT-83223 Support "Explicit context arguments" in the Analysis API
• KT-65186 K2: Analysis API: KtExpressionTypeProvider.getExpectedType works incorrectly for the right hand side of assignment expressions
• KT-76011 KaFirNamedClassSymbol#companionObject doesn't provide generated objects generated by compiled plugins
• KT-73290 Analysis API: Improve the architecture of content scopes and resolution scopes

Backend. J2KLIB

• KT-86368 [JKLIB] MetadataJVMModuleDeserializer tries to deserialize all symbols
• KT-86367 [JKLIB] kotlin.Cloneable built-in class not found
• KT-84877 [J2KLIB] Remove withKotlinBuiltinsHack present in JKlibIrLinker.kt
• KT-85846 Tests failing with fake override property missing accessors or backing field
• KT-85717 IllegalStateException due to already bound symbol
• KT-86204 [JKlib] Propagate private members from dependecies in the IR tree

Backend. Native. Debug

• KT-83804 Native: debug information generator converts relative paths to absolute ones

Backend. Wasm

• KT-83162 K/Wasm: renaming temporary and synthetic variables in the Chrome debugger
• KT-85008 Develop and publish a demo app using an early version of the component model support
• KT-76205 K/Wasm: stabilize and turn on incremental compilation by default
• KT-83728 [Wasm] Invalid Ir type while suspend call with blocked if null comprehansion
• KT-81637 K/JS/Wasm interop: Inconsistent behavior of is/as operations for JsReference<C> and C
• KT-65030 K/Wasm: memory allocator for Component Model ABI
• KT-83607 WasmJS: Production build eliminates 'else if' branch when 'else' is not wrapped with curly braces
• KT-82803 Kotlin/WASM: Failed to compile the doResume function with if inside catch block
• KT-83800 [Wasm] Closed world per-module compilation

Compiler

New Features

• KT-84487 "-Xcollection-literals" compiler flag
• KT-84072 Collection literals: treat visibility of of during resolve correctly
• KT-83165 Collection literals: treat Deprecated(HIDDEN) operators of reasonably
• KT-80500 Collection literals: Analyze ConeCollectionLiteralAtom in cases their expected type is not fully known
• KT-80491 Implement fallback mechanism for collection literals
• KT-80490 Implement overload resolution mechanism for collection literals
• KT-84298 K2: Generate IR for Companion Blocks & Extensions
• KT-83765 Make -Xsuppress-version-warnings have a diagnostic ID
• KT-84484 Companion Extensions Analysis & Resolution
• KT-84199 Implement DontMakeExplicitNullableJavaTypeArgumentsFlexible feature
• KT-84319 Add JVM target bytecode version 26
• KT-84297 Serialize & Deserialize Companion Block Declarations & Extensions to/from Metadata
• KT-84288 Companion Blocks Analysis & Resolution
• KT-84286 Parse Companion Blocks & Extensions
• KT-84292 Enforce Companion Blocks & Extensions Language Feature during Resolution
• KT-84291 Companion Blocks & Extensions Checkers
• KT-84290 Callable References to Companion Block Declarations & Extensions
• KT-84287 Build Raw FIR for Companion Blocks & Extensions
• KT-73256 Implement all meta-target for annotations
• KT-66344 K1 & K2: False positive WRONG_NUMBER_OF_TYPE_ARGUMENTS in callable reference to inner class member
• KT-76766 Warning is missing for wrong subclass checking
• KT-74049 Introduce special override rule to allow overriding T! with T & Any

Performance Improvements

• KT-84941 Skip linking klibs for generating ObjC headers
• KT-80367 Reduce memory consumption of DevirtualizationAnalysis
• KT-84412 iOS release build time dramatically increases with 2.3.20-Beta2 compared to 2.3.10
• KT-82559 linkDebugTest*X64 tasks are slower for Kotlin 2.3 than for 2.2
• KT-84095 Improve Unit tail-call optimization to support inline generic functions similar to suspendCoroutine

Fixes

• KT-77726 Move FirUnusedExpressionChecker to the default checkers list
• KT-84841 Collection literals: Drop special treatment of when with expected type
• KT-84732 Collection literals: "Expected FirCollectionLiteralImpl to be resolved" in RHS of equality operator
• KT-84675 Collection literals: 'Not singleClassifierType superType: TypeVariable(S)' in PCLA
• KT-84559 @OptIn on collection literal and context-sensitive does not work
• KT-84547 Collection literals: "Expected expression 'FirCollectionLiteralImpl' to be resolved" in elvis expression
• KT-80489 Collection literals: experimental version (Frontend)
• KT-84768 [K/N] switch thread state in org_jetbrains_skia_Canvas__1nDrawPicture to workaround the deadlock
• KT-52673 Don't report deprecation warning/error on last segments of imports
• KT-83988 Remove extraneous POP+GETSTATIC Unit for calls of Unit-returning suspend functions
• KT-77584 Support scripts built from LT in scripting API
• KT-80113 Consider improving diagnostic messages related to ==/===/is/as
• KT-85392 Native: concurrency issues in per-file caches
• KT-83938 Missing Tail call optimization in reference classes returning Unit
• KT-78432 No-arg constructor should be generated for regular classes with a value class parameter in case of JvmExposeBoxed
• KT-86130 False positive UNINITIALIZED_ENUM_COMPANION on LV 2.3 and lower
• KT-84860 False positive UNINITIALIZED_ENUM_COMPANION in enum access with explicit receiver in enum initializer when enum class has a companion
• KT-86210 Update -Xannotation-default-target CLI parameter doc
• KT-80590 Drop language version 1.9 for JVM
• KT-85948 Contracts in 2.4 stdlib is not compatible with 2.3 compiler
• KT-82123 KDoc: references that goes after markdown blocks don't have links
• KT-85957 Contract on function is getting discarded if any of effect declarations is unknown
• KT-84931 Incorrect type nullability in SAM super type in anonymous class-based SAM conversion
• KT-83766 K2: Wrong sourcePsi is set for SymbolPsiLiteral in SLC for annotation arguments referencing a const val
• KT-85062 Deprecate language version 2.1
• KT-79729 Kotlin should warn about orphaned block expressions, e.g. // if () \n { .... }
• KT-83884 The unused return value checker doesn't report a coercion from reference to Unit
• KT-85825 Context parameter lambda loses context type when wrapped in nested run blocks
• KT-37179 false-positive shadowing warning on local and member extension functions in presence of member extension property with invoke operator
• KT-84366 Invalid name for captured this in bytecode
• KT-84960 Property contract leaks unsubstituted type parameter in smart cast
• KT-84281 Standalone typealias-to-object qualifier allows type arguments and has type Unit in this case
• KT-84280 Standalone Unit qualifier allows type arguments: Unit<Any>
• KT-84380 Type alias to non-generic class can have (arbitrary number of) type arguments in LHS of ::class
• KT-84190 Implement basic functionality for returnsResultOf contract
• KT-83920 False positive "modifier 'value' is not applicable to 'local variable'" with soft keyword in positional destructuring (square bracket) declaration
• KT-84991 Improve Argument type mismatch diagnostics
• KT-82216 Sanitize '.kotlin_module' filename
• KT-85354 checkPsiTypeConsistency: add psi text attachments
• KT-85479 Improve diagnostic messages for upper bound violations
• KT-84585 Upper bound violated warning for expansion of type alias in LHS
• KT-84924 Native: stdlib-cache.lock used by mulitple processes
• KT-85244 False positive DUPLICATE_BRANCH_CONDITION_IN_WHEN with guard condition
• KT-85487 Investigate why WrapContinuationForTailCallFunctions does not work in Android Test
• KT-59633 K2: Implement running AndroidRunner tests with FIR
• KT-76237 Store File-level annotations in KLIB metadata separately
• KT-84198 Support multiple embedded .let-like calls with returnsResultOf contract
• KT-84196 Handle multiple entry/exit points for returnsResultOf functions
• KT-84195 Handle function references in returnsResultOf
• KT-85162 Introduce diagnostics to refine numeric types casting
• KT-80060 False positive REDUNDANT_CALL_OF_CONVERSION_METHOD in case of overloads
• KT-85289 False-positive smartcast from == with type parameter based variable
• KT-83890 return-value-checker: false positive "Unused return value of 'context'" on kotlin.context() functions
• KT-84106 False negative "NON_EXHAUSTIVE_WHEN": "NoWhenBranchMatchedException" at runtime with sealed and platform type
• KT-84717 Provide information for qualified expressions that might be replaced with context-sensitive simple names in IDE mode
• KT-38983 Bridges are not generated in interfaces, which leads to counterintuitive behavior of java.lang.reflect.Proxy
• KT-85005 Consider all: target in the checker of repeatable annotations
• KT-85210 Enabling -XXLanguage:+IntrinsicConstEvaluation breaks highlighting on some broken code
• KT-85217 Rework implementation supporting simple-to-suspend function conversion
• KT-85036 Introduce a proper handling of optional expectation annotations in platform checkers during metadata compilation
• KT-85086 False-negative JVM_EXPOSE_BOXED_CANNOT_BE_THE_SAME
• KT-84082 [OPT_IN_USAGE_ERROR] duplicates for destructuring declaration
• KT-85007 Properly implement special rules for kotlin.Result in @JvmExposeBoxed support
• KT-74383 Support new callable reference nodes in JVM backend
• KT-84828 Cleanup JVM backend from the old callable references-related code
• KT-85006 Refine error messages for INAPPLICABLE_ALL_TARGET diagnostic
• KT-84296 Support Companion Blocks in CFG
• KT-85058 Remove final field modification in DescriptorRendererOptionsImpl to prevent warnings on JDK 26+
• KT-72710 Incorrect behaviour of tail call suspend functions optimization
• KT-84727 [K/N] Segfault when returning null as generic Int type from dynamic framework
• KT-83460 Deprecation from @all:Deprecated is not propagated to property accessors/backing fields
• KT-84859 Skip deprecation phase for generic arguments in qualifier receiver of static call for companion block members and extensions
• KT-85050 [Swift Export] usage of inline classes with ref types crashes at runtime
• KT-84983 Type parameter annotations are lost for local functions
• KT-78800 Investigate FirMissingDependencySupertypeInQualifiedAccessExpressionsChecker
• KT-73945 K2 IDE: Duplicated inspections for redundant 'open' in interface member
• KT-84294 Ensure Context Sensitive Resolution works with Companion Blocks & Extensions
• KT-83904 [Inliner] Inline function overrides an abstract method with a default value in an inheritance chain
• KT-81675 Improve message for CONTEXTUAL_OVERLOAD_SHADOWED
• KT-84994 Rework optimization for companion extension resolution
• KT-81598 incorrect type mismatch error messages for generic calls with explicit type arguments
• KT-84185 Type arguments are wrongly allowed in receivers of static calls
• KT-83441 False positive: REDUNDANT_CALL_OF_CONVERSION_METHOD
• KT-83587 K2: Missing null-check when using == on Short! and Byte! platform types
• KT-84405 ClassCastException with conflicting projection on the LHS of a callable reference
• KT-84866 Reserve CoroutineContext as context parameter for future use
• KT-65239 K2: Render FIR declaration instead of IR-based descriptors in IR signature clash diagnostics
• KT-84743 Type parameter declared as 'in' can be used in 'out' position in DNN & flexible types
• KT-84720 "Unused return value" is not reported inside used if/when multi-statement blocks
• KT-84310 No Warning Emitted For Deprecated Java Enum Value Usage
• KT-81871 Drop context receiver tests
• KT-84714 KJS: Forbid exporting properties with context parameters
• KT-80701 Native: -Xbinary=cCallMode is not integrated with compiler caches
• KT-84000 Native: test pre-codegen inliner on CI
• KT-57557 Implement getAndSet for AtomicNativePtr via getAndSetField intrinsic
• KT-84352 createUninitializedInstance generates invalid LLVM for value classes
• KT-84234 Rename CONST_VAL_WITHOUT_INITIALIZER diagnostic for properties with EBF
• KT-84411 Confusing message for the class reference of the inner class with the type parameter
• KT-84594 EBF is smartcasted in inline function with @PiblishedApi
• KT-83989 Update coroutines-codegen.md after changes of Unit tailcall optimization
• KT-84452 EBF is smartcasted in the default argument with noinline modifier
• KT-80925 Replace "useless" in diagnostic messages
• KT-83646 Native: don't use sun.misc.Unsafe in ByteArrayStream when running on JVM 24+
• KT-82122 Prohibit arbitrary placement of type parameters in callable reference LHS
• KT-82574 Fixation: consider preferring EQUALS constraints to LOWER ones
• KT-83564 Consider dropping HAS_PROPER_NON_NOTHING_NON_ILT_LOWER_CONSTRAINT
• KT-84213 Flaky incremental compilation behaviour with EBF
• KT-84133 Adopt initInstance to handle value classes
• KT-24840 Square bracket escaping in KDoc
• KT-84167 Invalid type references with type arguments in package parts compile without diagnostics
• KT-84209 False negative ACTUAL_ANNOTATIONS_NOT_MATCH_EXPECT on context parameters of function types
• KT-83354 Wrong position for lambda context type error
• KT-84206 Remove forcesPreReleaseBinaries = true from ExplicitBackingFields
• KT-83524 An anonymous function with named parameters throws FileAnalysisException
• KT-84155 K2: NO_CONTEXT_ARGUMENT caused by stale value in NewConstraintSystemImpl.hasContradictionInForkPointsCache
• KT-83829 False-negative INVALID_DEFAULT_FUNCTIONAL_PARAMETER_FOR_INLINE
• KT-83842 KIAEWA: Exception in expression checkers for @OptIn(markerClass=[…])
• KT-84045 Evaluate default arguments of annotation's parameters using FIR evaluator
• KT-83987 Refactor/fix CoroutineCodegen.isReadOfInlineLambda()
• KT-83772 Create a language feature for wrapContinuationForTailCallFunctions
• KT-84061 K2: IllegalStateException: FirResolvedNamedReference expected on plusAssign for array element with unresolved initializer inside buildList
• KT-83985 Drop arrayOf check from EscapeAnalysisChecker after bootstrap update
• KT-78885 Current frame disappears from stack trace when debugging inline-heavy suspend code
• KT-78727 Split KonanConfig into NativeFrontendConfig and NativeBackendConfig
• KT-83755 Support rendering of evaluated and original arguments in FirAnnotationRenderer#renderAnnotation
• KT-17763 Inner class constructor has incorrect generic signature in the bytecode
• KT-83625 Initialize annotations on Java record components
• KT-83795 Compiler crash on suspend lambda as default parameter of inline function
• KT-72880 Calls with incorrect VarHandle method signatures are generated with -Xjdk-release being used
• KT-67809 Native: remove support for non-opaque LLVM pointer types
• KT-82148 Suspend function returns the wrong value and not Unit
• KT-55559 JVM: ClassCastException with Unit returning suspend function and tail-call Non-Unit returning suspend function and callable reference
• KT-70995 Kotlin/Native: Treat all @HasFinalizer types as escaping in Escape Analysis
• KT-83903 'when' with 'val' does not take previous nullability check into account
• KT-83952 StackEntries for tail-call suspend functions have internal names for classes instead of FQ names
• KT-83377 Investigate usage of declarationSymbols in resolve of local user type
• KT-83770 Smartcast doesn't work for an explicit backing field with multiple intersections
• KT-83650 Native: don't use sun.misc.Unsafe in CastsOptimization when running on JVM 24+
• KT-83754 KotlinIllegalArgumentExceptionWithAttachments for explicit backing field with annotated type
• KT-83756 Error while resolving FirNamedFunctionImpl with explicit backing field and implicit type
• KT-83563 Consider dropping fixation readiness REIFIED
• KT-83713 K2: No error with external primary constructor parameter
• KT-83104 K2: No error with external enum entry
• KT-83696 Consider dropping HAS_NO_RELATION_TO_ANY_OUTPUT_TYPE readiness
• KT-83308 K/N: "IllegalArgumentException: An interface expected but was Any"
• KT-81590 Switch latest stable version in Kotlin project to 2.4
• KT-66701 K2: Java interface method override via Kotlin class rejected
• KT-56563 Inference within if stops working when changing expected type from Any to a different type
• KT-261 Can't specify function return type in a subclass

Compose compiler

New features

• c1bbb47 Started inferring the stability of all interfaces to be Stability.Unknown, expect for those explicitly marked as known stable.

Fixes

• b/511102714 Made the default stability of non-final classes Unknown instead of Stable
• b/509945632 Do not generate groups in inline lambdas without @Composable calls.
• b/504284805 Fix indentation for generated proguard mappings.
• b/422193018 Fix applier inference for nested composables of different types.
• b/497751457 Prevent a $stable property from being added to any object.
• b/427530633 Do not infer a getter call as static across when it is defined in another file.
• b/427530633 Started using Stability.Runtime more broadly. Now, when an element depends on the stability of an internal or public class defined in another file, the element will no longer infer the stability of that class and will depend on the runtime stability of that class instead.

IR. Actualizer

• KT-84293 Expect Actual Matching for Companion Block Declarations & Extensions

IR. Inlining

• KT-73708 Use some marker in KLIBs produced with IR inliner
• KT-85605 "Local delegated property has not delegate" exception when calling inline function containing delegated property in a lambda from within an inline lambda
• KT-84112 Intra-module inliner: No container found for type parameter 'T'
• KT-84416 High memory usage for IrFileEntry after enabling inliner
• KT-75396 [IR] Pass LoweringContext to inline and serialization checkers

IR. Interpreter

• KT-86083 Create a new CLI flag to enable IntrinsicConstEvaluation feature
• KT-80804 Enable constant evaluation for more standard library
• KT-83514 Get rid of EvaluatedConstTracker
• KT-84561 K2: Convert evaluated constant by default in FIR2IR

IR. Tree

• KT-79663 KLIB-based compilers: Promote partial linkage to "always on"
• KT-76934 Drop old IR parameter API
• KT-72950 Partial Linkage: Change the semantics of -Xpartial-linkage-loglevel
• KT-74763 Build: refactor ':compiler:backend.common' and ':compiler:ir.backend.common' modules
• KT-76634 PL: Don't report warnings in cases that don't lead to runtime errors
• KT-79801 KLIBs: Implement checks for symbols loaded by the compiler on 1st and 2nd phases
• KT-72812 IR serializer: Don't serialize any cinterop fake overrides to Klibs

JVM. Reflection

Fixes

• KT-86017 KClass.constructors returns all java.lang.String constructors for mapped type kotlin.String
• KT-85550 Reflection: KParameter.type.classifier returns boxed KClass for non-nullable primitive types
• KT-82659 Reflection: IAE on a call to a Java inner class constructor
• KT-85999 Reflection: ByteArray KType incorrectly has type arguments in Kotlin 2.4.0
• KT-85285 Reflection: InvocationTargetException (UInt cannot be cast to Integer) when reading UInt annotation property via getter
• KT-85091 Reflection: "KotlinReflectionInternalError: Unsupported parameter owner: null" on attempt to get annotations of annotation constructor parameter
• KT-85322 Reflection: KotlinReflectionInternalError when loading ProGuard-obfuscated code compiled before 2.3.20
• KT-84679 Reflection: confusing "Kotlin reflection is not yet supported for synthetic Java properties" for reference to Java enum's entries property
• KT-85025 KTypeParameter instances not equal to each other for the same type parameter in member specialization KFunction
• KT-84796 Reflection: mutable flexibility is lost for K1-based types in KClass.allSupertypes
• KT-84494 Reflection: Java Collections have differences in kotlin supertypes from old K1 reflection
• KT-84382 Reflection: raw list in Java type is transformed to List instead of MutableList
• KT-84492 Reflection: supertypes of raw list in Java type are not raw
• KT-84076 Reflection: list in Java type is transformed to flexible instead of mutable list
• KT-14990 'callBy' for inner class constructor fails at run-time
• KT-82881 Reflection: update KCallable.callBy kdoc to mention vararg parameters
• KT-84075 Reflection: wildcard in Java type is transformed to out Any! instead of star projection

JavaScript

New Features

• KT-51292 Proposed behavior of @JsExport on interfaces and classes with companion objects
• KT-21626 Support ES2015 syntax in js function
• KT-83451 K/JS: Support ES6 object destructuring in js() calls
• KT-83452 K/JS: Support ES6 array destructuring in js() calls
• KT-82128 [K/JS] Allow named companion objects in exported interfaces

Performance Improvements

• KT-77646 KJS: optimize Byte/Char/Short/Int/Float/DoubleArray.copyOf(newSize)

Fixes

• KT-84332 KJS: Reconsider disallowing nested classes in exported interfaces
• KT-72198 KJS: ES2015 interop with ValueClass
• KT-84090 Save variance in the generated TypeScript
• KT-56618 KJS/IR: Support external interfaces from common code (via annotation?)
• KT-85038 Kotlin/JS: @JsExport on sealed external interface with companion object causes NPE
• KT-81787 KJS: Value class type lost when using JsExport on interface
• KT-85411 Fix conversionCombinations.kt tests for the JS target
• KT-83701 Escaped identifier with a quote cause an invalid d.ts file
• KT-68281 K/JS: Order of classes in initMetadataForClass are not deterministic
• KT-15101 js: Same callable references are not equal
• KT-84810 [K/JS] Callable references operator produces duplicates
• KT-85323 JsClass optimization doesn't work well for primitives
• KT-60651 KJS / ES6: init block and constructor are not called
• KT-84601 K/JS: KClass<> reference doesn't work in JS counterside as a new target in ES6 mode
• KT-85099 KotlinJS: JsPlainObject from the js-plain-objects plugin does not respect overrides
• KT-84615 KJS: Forbid @JsStatic on extension functions/properties
• KT-84002 Bump version from 2.3 to 2.4 for JsNoRuntime-related annotations
• KT-84474 Kotlin/JS: Long::class becomes null when passing the value to a generic function with -Xes-long-as-bigint
• KT-84647 K/JS: Class expressions are not supported in js() calls
• KT-84458 KJS: Fully support @JsStatic in Analysis API-based TypeScript Export
• KT-84454 KJS: Generate protected overrides for abstract class inheritors in Analysis API-based TypeScript Export
• KT-84490 KJS: Fix mutability of exported top-level variables Analysis API-based TS export with ES modules
• KT-84459 KJS: Support default exportability in Analysis API-based TypeScript Export
• KT-84456 KJS: Support deprecation comments in Analysis API-based TypeScript export
• KT-82264 Implement exporting classes in Analysis API-based TypeScript Export
• KT-84233 K/JS: exported collection views doesn't provide Iterator methods
• KT-82127 Remove generator-based coroutines intrinsics after bootstrap
• KT-84003 Remove @Suppress from JsReference after bootstrap
• KT-44753 KJS / IR: @JsExport non-public fun exports nothing
• KT-83992 Drop K1 JS entry point and IC code
• KT-83722 K/JS: NON_EXPORTABLE_TYPE in the exported file with name-based destructuring declarations
• KT-69353 KJS / d.ts: Kotlin does not export base collection classes along with their mutable collection counterparts

Klibs

Performance Improvements

• KT-84415 Ineffective hashMap usage in IrSymbolDeserializer
• KT-80903 [Klib] Optimize size of serialized IR element coordinates
• KT-84451 [Klib] Use varint encoding for element sizes in IR tables
• KT-84400 [Klib] Optimize size of serialized IrExpression
• KT-79675 K/N: Uncached ZipFIleSystemAccessor

Fixes

• KT-78188 [JS] Klib backward and forward compatibility testing
• KT-82471 [K/N] Klib forward compatibility testing with codegen tests
• KT-83929 Add tests for IR signatures of static properties and functions
• KT-81411 Merge KonanLibrary to KotlinLibrary to simplify adoption of KlibLoader in the Kotlin/Native compiler
• KT-82469 [K/N] Klib backward compatibility testing with codegen tests
• KT-84511 [Native][Tests] Improve descriptor-related logic in NativeCliBasedFacades.kt
• KT-85017 [PL] Add test for added internal abstract fun
• KT-84488 Export in previous version: Prohibit using on 2nd stage
• KT-85149 Klib Dump parser: fix parsing of qualified names adjacent to vararg symbol
• KT-85129 Klib Dump parser: fix enum names parsing
• KT-84684 Remove UserVisibleIrModulesSupport from IR linker
• KT-84820 [K/N] Load libcallbacks and libllvmstubs from configured path
• KT-84819 K/N: Segfault on xctest when using internal abstract on a parent class
• KT-83807 Restore non-nullability of symbols not available in 2.3.0 stdlib
• KT-83012 Export in previous version (Native): add the checker for incompatible Kotlin stdlib/compiler pairs
• KT-84341 Fix detection of box function in forward compatibility tests
• KT-83748 Bump versions in JS Klib compatibility testing
• KT-83724 Fix & unmute stdlib & kotlin-test compatibility tests
• KT-83151 Restore non-nullability of symbols available since 2.3

Language Design

• KT-14663 Support having a "public" and a "private" type for the same property
• KT-80852 Version overloading: generate overloads corresponding to different versions of a function whose parameters are annotated with @IntroducedAt(<version>)
• KT-73821 Decide the future of the ForbidUsingSupertypesWithInaccessibleContentInTypeArguments language feature
• KT-85120 @IntroducedAt on expect parameter cannot be properly actualized

Libraries

New Features

• KT-84921 Add 'returnsResultOf' contract to appropriate declarations in the stdlib
• KT-73111 No UInt.toBigInteger() and ULong.toBigInteger() conversion function
• KT-78499 Add isSorted() extension to standard library

Performance Improvements

• KT-70750 Kotlin's Regex implementation on Kotlin Native is painfully slow
• KT-67731 Regular expressions works slowly on iOS
• KT-80772 K/N: Regex: improve look behind matching performance for "fixed-length" patterns

Fixes

• KT-83525 Introduce support window for Kotlin Stdlib versions
• KT-86027 Hide returnsResultOf under a separate flag and remove its usages from kotlin stdlib
• KT-84818 [Regex] Native and Wasm: Decomposed Unicode character are incorrectly process with CANON_EQ flag
• KT-83131 Testing: assertNull has no contract
• KT-85122 Deprecate kotlin.io.readLine with WARNING
• KT-84970 Deprecate AbstractCoroutineContextKey and associated API
• KT-81395 Stabilize kotlin.uuid.Uuid API
• KT-85127 Remove kotlin.test.assert*NoInline hidden functions
• KT-84264 Add appropiate @SinceKotlin to new contracts
• KT-84697 Update the list of JDKs the stdlib is tested with
• KT-83956 Clarify joinToString behavior when the receiver is empty
• KT-61180 kotlin.ArrayIndexOutOfBoundsException on Native with Regex, works on Android/JVM though
• KT-84871 compareValues, nullsFirst, nullsLast return 0 for -0.0 and 0.0 on JS
• KT-84691 Add samples for toBigInteger extension functions
• KT-84372 PathExtensionsTest.copyToRestrictedReadSource fails with JDK22+
• KT-84369 StringJVMTest.formatter fails with JDK13+
• KT-84613 String.toDouble() produces incorrect results on Wasm for large exponent values
• KT-76905 Add samples for kotlin.math functions
• KT-84355 Reduce the number of iterations for the removeHashAtStressTest
• KT-83962 List.listIterator(Int) KDoc's exception condition is incorrect
• KT-83958 Improve enumValueOf documentation
• KT-83953 Add samples for kotlin.time extension functions
• KT-83951 Rewrite stdlib samples to use assertPrints instead of assertEquals

Native

New Features

• KT-78686 LLVM update Q1 2026
• KT-84826 Bump the minimum deployment version of Apple targets

Fixes

• KT-84686 Removing x64 in gradle file breaks builds on certain platforms
• KT-71278 Enable Concurrent Mark and Sweep (CMS) GC by default
• KT-81748 Create a phased CLI for Native klib compilation
• KT-84733 LLVM Update: rebase LLVM once the upstream stabilizes
• KT-83914 Native: when loading JNI libraries, java.library.path can contain system directories with libraries with same names
• KT-83133 Native: don't use sun.misc.Unsafe in the compiler and cinterop when running on JDK 25+
• KT-83648 Native: don't use sun.misc.Unsafe in NativeMemoryAllocator when running on JDK 25+
• KT-83647 Native: don't use sun.misc.Unsafe in nativeMemUtils when running on JDK 25+
• KT-82674 Native: dyld[...]: Symbol not found: _mach_vm_reclaim_update_kernel_accounting_trap on macOS
• KT-82879 Native: DLLs in the Windows distribution are not reproducible
• KT-83283 Test Kotlin/Native performance tests compilation in Gradle 9.0
• KT-82872 Native: make Kotlin/Native distribution compiler cache reproducible for Linux
• KT-82871 Native: cstubs.bc for android_* platform libraries contain absolute paths in string literals
• KT-34467 Cinterop: Clang crashes when -fmodule-map-file is specified (SIGSEGV)

Native. Build Infrastructure

• KT-85803 K/N: build not reproducible - platformLibs caches
• KT-84503 Duplicate META-INF/serialization.shadow.kotlin_module entry in kotlin-native-compiler-embeddable jar
• KT-85191 K/N: Dependency cycle in libclangInterop
• KT-84937 Kotlin/Native: non-reproducible .bc for mingw_x64
• KT-80072 Make Kotlin/Native distribution reproducible
• KT-81771 konanc failing to load native libraries

Native. C Export

• KT-61748 KMM- warnings when compiling native targets (Kotlin 1.9.0)

Native. C and ObjC Import

• KT-85705 Swift-generated headers with external_source_symbol produce duplicate enum declarations
• KT-82379 Introduce lenient modular cinterop mode
• KT-81695 Repeated typedefs across multiple clang modules break cinterop with -fmodules
• KT-82766 K/N: external_source_symbol clang attribute causes cinterops with -fmodules to downgrade to forward declaration
• KT-84023 Modular import fails with an obscure error when the failing module is not the last one
• KT-81433 Generate C-interop KLIBs in previous ABI version in Kotlin 2.4.0
• KT-82402 Inter-cinterop type reuse with -fmodules uses forward declaration when an actual declaration is available
• KT-82377 Fix ObjC forward declaration handling in modular cinterops
• KT-81752 Native: investigate and remove filtering of -fmodule-map-file in cinterop
• KT-83814 Native: includedHeaders= in platform libs manifests is not reproducible when modules= is used

Native. ObjC Export

• KT-86068 Native: add support for ObjCEnum.EntryName
• KT-85171 Red Swift code in Native UI Multiplatform App project from Template Gallery

Native. Runtime

• KT-84331 Kotlin/Native: RunLoopFinalizerProcessor needs initialized runtime before it has any jobs

Native. Runtime. Memory

• KT-83670 K/N: gc concurrent mark phase assert Failed to terminate mark in STW in a single iteration
• KT-80770 Kotlin/Native: revise ObjC refcount methods called in runnable state
• KT-84640 Native: comment for kotlin.native.runtime.SweepStatistics misses the word "number"

Native. Swift Export

New Features

• KT-84361 [Swift Export] Preserve TypeInfo on StateFlow
• KT-85130 [Swift Export] Preserve TypeInfo on SharedFlow
• KT-82705 Support convenient export of Flow types in Swift export
• KT-66821 Swift Export: value class
• KT-82598 Swift Export: Custom name translation
• KT-69431 Swift export: inline functions
• KT-84263 [Swift Export] Context Parameters on Functional Types

Fixes

• KT-80305 Support coroutines in Swift Export
• KT-85380 [Swift Export] Attempt to bridge unbridgeable type: SirUnsupportedType
• KT-84317 Swift Export: "protocol members can only be marked unavailable in an '@objc' protocol" in generated code for kotlinx-coroutines
• KT-85704 [Swift Export] cannot infer generic type of function returning a generic type
• KT-85711 [Swift Export] suspend function returning non-null generic fails to compile
• KT-85715 [Swift Export] generic interface in typealias fails to compile
• KT-85714 [Swift Export] unsupported input type param in functional receiver
• KT-83743 Swift export: type arguments expected for generic typealias
• KT-85458 [Swift Export] value of a closure returning a closure generates invalid swift code
• KT-85521 [Swift Export] conflicting overloads for generated Kotlin bridges
• KT-85293 SwiftExportCoroutinesWithResultValidationTest.testCoroutines fails after cross-push
• KT-84515 [Swift Export] suspend functional parameter generates invalid Swift code
• KT-82282 Swift Export: suspend function returning Array leads to incompilable code
• KT-81540 Swift Export: using interface in Set generates incompilable code
• KT-66873 Swift Export: suspendable contravariant functional type
• KT-85272 [Swift Export] conflicting imports for kotlinx-coroutines
• KT-85163 [Swift Export] Flow of Unit values crashes
• KT-85159 [Swift Export] Flow is not properly being cancelled
• KT-84226 [Swift Export] Flow in contrvariant position is not allowed
• KT-84485 [Swift Export] Flow with nullable elements
• KT-83730 Generated Swift switch on bridged Kotlin enum crashes with fatalError
• KT-85016 [Swift Export] it's not OK to expose Flow as AsyncSequence
• KT-84979 Swift Export Nullability: Unit
• KT-83821 Swift Export: suspend function returning Nothing leads to incompilable code
• KT-81593 Swift Export: suspend function returning Unit leads to incompilable code
• KT-84359 [Swift Export] nested functional type with Unit parameter
• KT-84358 [Swift Export] functional type with Unit parameter
• KT-84356 [Swift Export] functional type with single Unit parameter
• KT-83567 Swift Export: "IllegalStateException: Internal compiler error: doesn't correspond to any C type: kotlin.Unit": invalid closure is generated for suspend function which returns Unit
• KT-83397 [Swift Export] Functional return type with Unit parameter is emitted as invalid void parameter list ('void' must be the first and only parameter)
• KT-84243 [Swift Export] Returning value of suspending functional type from suspending function yields invalid code
• KT-82568 Swift Export: Context Parameters
• KT-83398 [Swift export] converting non-escaping parameter to generic parameter may allow it to escape
• KT-83389 Swift Export: "ClassCastException" caused by suspend fun throwing Error
• KT-83116 Swift export generates bridges incompatible with language version 2.4
• KT-83749 [Swift Export] varargs and List uses the same mangling on bridges
• KT-83712 Swift Export ignores internal setter and generates invalid bridge code

Tools. BCV

• KT-83476 Use Maven publications as dump input [ABI Validation]
• KT-78341 Outer scope's visibility is not considered when dumping const vals [ABI Validation JVM]
• KT-78305 Private constructor is written in ABI dump
• KT-82724 BCV incorrectly reports generated @JvmOverloads declarations as public
• KT-78367 Internal constructor infiltrated into a dump
• KT-78366 Protected method of enum should not be included into a dump

Tools. Build Tools API

New Features

• KT-83794 Make BTA JVM Compiler Arguments Type-Safe
• KT-80963 BTA: Add structured information about reported messages to KotlinLogger
• KT-73037 Add input (like compiler arguments) changes tracking
• KT-82791 BTA: introduce an option for ExecutionPolicy.WithDaemon to control the daemon log files path
• KT-84453 SSoT: provide a unified way to convert Enums to Strings

Fixes

• KT-86395 [BTA] forward-compatibility violation: NoSuchMethodError on JvmSnapshotBasedIncrementalCompilationConfiguration.<init> breaks IC
• KT-80679 Add support for the Build Tools API [ABI Validation]
• KT-85294 BTA: Replace hardcoded @since in KDoc with dynamic versioning
• KT-85035 Don't expose X_COMPILER_PLUGIN_ORDER in CommonCompilerArguments
• KT-85391 [BTA] Hide boilerplate required to load isolated BTA implementation
• KT-85447 BTA: deprecate JvmCompilerArguments.contains (warning)
• KT-82390 [BTA] Remove deprecated non-builder factory functions and classes
• KT-84850 Make kotlin-home type safe
• KT-84867 Make Xphases-to-* arguments type-safe
• KT-85094 Make Xwarning-level type safe
• KT-85205 Make Xdump-perf type safe
• KT-85204 Make Xdump-directory type safe
• KT-84906 Make enum-based common arguments type-safe
• KT-84322 Make X_PROFILE BTA compiler argument type safe
• KT-84825 Make script-templates type safe
• KT-84546 Replace raw string path arguments with type-safe PathListType
• KT-84705 Make Xjdk-release to type-safe
• KT-85167 Make Xjsr305 type safe
• KT-85069 Make Xnullability-annotations type safe
• KT-84738 Make Xscript-resolver-environment type safe
• KT-85082 Make Xignored-annotations-for-bridges type safe
• KT-84324 Make X_ADD_MODULES BTA compiler argument type safe
• KT-84338 Make enum BTA JVM compiler argument type safe
• KT-84325 Make JVM_DEFAULT BTA compiler argument type safe
• KT-75837 IC: Shrunk classpath snapshot name is hardcoded
• KT-84228 BTA: Improving KDoc generation for Enums and Custom Types
• KT-85738 BTA forward compatibility: NoSuchFieldError on X_IGNORED_ANNOTATIONS_FOR_BRIDGES when API 2.3.0 is used with impl 2.4.0
• KT-84436 Сompiler warnings are missing under Gradle -q option with -Werror
• KT-85072 AbstractMethodError when calling discoverScriptExtensionsOperationBuilder with pre-2.4.0 compiler
• KT-84523 Add more forward compatibility tests
• KT-84187 [BTA] Add more build operation immutability tests
• KT-84219 [BTA] Add additional tests on basic metrics collection
• KT-83781 Add additional tests for KT-79975 (BTA ability to cancel build operations)
• KT-85092 [BTA] Update BTA Backward Compatibility Testing: 2.3.20-RC → 2.3.20
• KT-85439 BTA: Warn or error when incompatible compiler arguments are passed via applyArgumentStrings
• KT-75540 Build Tools API Should Reject -Xbuild-file Argument
• KT-85333 Add BTA tests for BACKUP_CLASSES and KEEP_IC_CACHES_IN_MEMORY behavior after compilation error
• KT-84770 BTA: default options cannot be retrieved from many option objects
• KT-85224 Add @ExperimentalArgumentApi to compiler argument DSL types
• KT-84953 Fail TC build if generated files change
• KT-85189 Refactor path argument types: flatten hierarchy and improve naming
• KT-82335 Promote the deprecation level for BTA prototype to the ERROR level
• KT-84984 Runtime NPEs caused by null return in CompilerMessageRenderer implementation
• KT-84015 Introduce detection of custom script names to new BTA API
• KT-83972 BTA: use isolated classloader for loading the BTA implementation in integration tests
• KT-84181 More verbose warning when CRI is enabled without using BTA
• KT-84449 Platform-Specific File.pathSeparator Hardcoded During SSOT Generation
• KT-84249 Fix hardcoded path separator in -Xprofile argument to support absolute paths on Windows

Tools. CLI

Fixes

• KT-84609 Remove Nullability from Array-based CLI Compiler Arguments
• KT-85414 Argument DSL: delimiter = KotlinCompilerArgument.Delimiter.PathSeparator generates invalid Kotlin code
• KT-85004 Set proper since version for language feature about property annotation targeting
• KT-84220 Enable Context Parameters by default in LV 2.4
• KT-84188 Create CLI argument for explicit context parameters
• KT-84999 Don't poison binaries with ImplicitJvmExposeBoxed language feature
• KT-85001 Convert ImplicitJvmExposeBoxed language feature to analysis flag
• KT-83341 Don't use the extension point registration mechanism from Intellij for K2 extensions
• KT-56850 Separate K/Wasm CLI entry point from K/JS CLI
• KT-84132 CLI: regression in deduplication of same-value arguments
• KT-83261 No error if pass an arbitrary string to a CLI argument that changes language features
• KT-83172 Boolean CLI argument for a language feature with explicit false value is allowed but has no effect

Tools. CLI. Native

• KT-82482 Compiler plugins are not propagated to frontend environment in ONE_STAGE_MULTI_MODULE Native mode

Tools. Compiler Plugin API

• KT-85969 KtLint incompatible with Kotlin 2.4.0-Beta2 (parsing errors / Extensions storage issue)
• KT-85133 Drop deprecated K1 specific methods from IrPluginContext

Tools. Compiler Plugins

New Features

• KT-66808 PowerAssert: Add support for third-party assertion libraries
• KT-69036 Power-Assert indent multiline values
• KT-75656 PowerAssert: Create runtime library

Fixes

• KT-83931 Power Assert: Compilation fails when using the metro plugin
• KT-86170 PowerAssert: Stabilize runtime ABI for initial release
• KT-85250 PowerAssert: Automatically add runtime library dependency
• KT-75873 PowerAssert: display callable reference value under '::'
• KT-85151 PowerAssert: Surround string and character values with quotes
• KT-85184 PowerAssert: Annotation may only be used on expect and non-override functions
• KT-85178 PowerAssert: Crash when transforming IrCall without CallableId
• KT-66807 PowerAssert: Improve output diagram formatting
• KT-85089 PowerAssert: Wasm CompileError when using PowerAssert.explanation
• KT-75266 PowerAssert: arrayOf() isn't displayed on the diagram
• KT-67332 "IndexOutOfBoundsException: Cannot pop operand off an empty stack." caused by function reference
• KT-83330 Lombok. An add methods with @Singular annotation in Java record doesn't work from kotlin
• KT-83204 Lombok. If @Data and @NoArgsConstructor are used together, then the constructor from @Data shouldn't be available
• KT-83336 Lombok. IllegalAccessError for constructor if @Value and @Builder are applied and used from another package
• KT-83352 Lombok. FileAnalysisException when @SuperBuilder is used with @Builder
• KT-83325 Lombok. Constructor with parameters is unavailable for a class with @Builder

Tools. Compiler plugins. Serialization

• KT-85963 IncompatibleClassChangeError: Expected non-static field $stable on deserialization of @Serializable data class when Compose compiler plugin is applied before Serialization plugin
• KT-85554 Serialization: "IndexOutOfBoundsException" on property generated by Compose plugin

Tools. Gradle

New Features

• KT-76197 Write Kotlin compiler warnings and errors to Problems API

Fixes

• KT-86346 Compiler warnings printed twice in console — once as w: and again as Gradle "Problem found:" block
• KT-69701 Gradle: module name is passed inconsistently to different types of compilations
• KT-85373 Compile against Gradle API 9.5.0
• KT-85374 Run tests against Gradle 9.5.0
• KT-80448 Remove internal & deprecated API from ExtrasProperty.kt
• KT-69830 Support Gradle com.gradle.develocity plugin in KGP
• KT-85509 Remove deprecated API in the 2.4.0 release
• KT-83858 Compatibility with Gradle 9.4.0 release
• KT-84144 Bump the minimal supported AGP version to 8.5.2
• KT-85562 Failed to invoke getCompilation on org.jetbrains.kotlin.gradle.tasks.KotlinNativeLink_Decorated on project import
• [KT-85590](https://youtrack.jetbrains.com/issue/KT

Note truncated.

Changelog

Backend. J2KLIB

• KT-86367 [JKLIB] kotlin.Cloneable built-in class not found

Compose compiler

• b/511102714 Made the default stability of non-final classes Unknown instead of Stable

Tools. Build Tools API

• KT-86395 [BTA] forward-compatibility violation: NoSuchMethodError on JvmSnapshotBasedIncrementalCompilationConfiguration.<init> breaks IC

Tools. Gradle

• KT-86346 Compiler warnings printed twice in console — once as w: and again as Gradle "Problem found:" block

Tools. Gradle. BCV

• KT-86268 ABI validation tasks fail with Unsupported platform toolchain type when using kotlin.compilerVersion pointing to an older compiler after BTA migration in 2.4.0-Beta2

Tools. Gradle. Wasm

• KT-86457 [Wasm, Gradle] BinaryenExec.standardOutput is silently ignored after migration to Gradle Workers

Changelog

Backend. J2KLIB

• KT-84877 [J2KLIB] Remove withKotlinBuiltinsHack present in JKlibIrLinker.kt
• KT-85846 Tests failing with fake override property missing accessors or backing field
• KT-85717 IllegalStateException due to already bound symbol
• KT-86204 [JKlib] Propagate private members from dependecies in the IR tree

Compiler

• KT-86210 Update -Xannotation-default-target CLI parameter doc
• KT-85948 Contracts in 2.4 stdlib is not compatible with 2.3 compiler
• KT-85957 Contract on function is getting discarded if any of effect declarations is unknown
• KT-86130 False positive UNINITIALIZED_ENUM_COMPANION on LV 2.3 and lower
• KT-84860 False positive UNINITIALIZED_ENUM_COMPANION in enum access with explicit receiver in enum initializer when enum class has a companion
• KT-84319 Add JVM target bytecode version 26
• KT-85825 Context parameter lambda loses context type when wrapped in nested run blocks
• KT-84960 Property contract leaks unsubstituted type parameter in smart cast

Compose compiler

• b/509945632 Do not generate groups in inline lambdas without @Composable calls

IR. Interpreter

• KT-86083 Create a new CLI flag to enable IntrinsicConstEvaluation feature

JVM. Reflection

• KT-86017 KClass.constructors returns all java.lang.String constructors for mapped type kotlin.String
• KT-85999 Reflection: ByteArray KType incorrectly has type arguments in Kotlin 2.4.0

Libraries

• KT-86027 Hide returnsResultOf under a separate flag and remove its usages from kotlin stdlib

Native

• KT-84733 LLVM Update: rebase LLVM once the upstream stabilizes

Tools. Compiler Plugin API

• KT-85969 KtLint incompatible with Kotlin 2.4.0-Beta2 (parsing errors / Extensions storage issue)

Tools. Compiler Plugins

• KT-86170 PowerAssert: Stabilize runtime ABI for initial release
• KT-85250 PowerAssert: Automatically add runtime library dependency

Tools. Compiler plugins. Serialization

• KT-85554 Serialization: "IndexOutOfBoundsException" on property generated by Compose plugin
• KT-85963 IncompatibleClassChangeError: Expected non-static field $stable on deserialization of @Serializable data class when Compose compiler plugin is applied before Serialization plugin

Tools. Gradle

• KT-85373 Compile against Gradle API 9.5.0
• KT-85374 Run tests against Gradle 9.5.0

Tools. Gradle. Multiplatform

• KT-85877 The number of SPM direct dependencies is multiplied on number on targets
• KT-85706 SwiftPM Import: Updating package version in build script updates version in the lock file
• KT-83370 Incorrect metadata transformation for stdlib's webMain source set

Tools. Gradle. Native

• KT-85984 linkReleaseFrameworkIosSimulatorArm64 is executed during Debug iOS build since 2.4.0-Beta2
• KT-86024 Empty main compilations cause w: [COMPILER_ARGUMENTS_WARNING] There are libraries in -friend-modules CLI argument that are not included in -library CLI argument:

Tools. Gradle. Wasm

• KT-85974 K/Wasm: Do not set -Xir-per-module for Wasm tasks

Changelog

Analysis API

• KT-65683 Analysis API: Dangling file session creation causes a computeIfAbsent contract violation

Analysis API. FIR

• KT-70896 AA: False positive deprecation warning with override of built-in method in JDK mapped class
• KT-84625 Analysis API: collectDesignationPath fails for nested classes inside plugin-generated top-level classes

Analysis API. Infrastructure

• KT-84913 Extract compiler classes used by the PSI & Analysis API to a separate module
• KT-64986 Analysis API: Implement Analysis API tests for different KMP Platforms
• KT-80379 Extract per-module test generators for AA tests

Analysis API. PSI

• KT-84715 removeModifier doesn't delete whitespaces around the removed modifier
• KT-84564 KtEnumEntry.delete deletes semicolon
• KT-84781 Use computed properties in KotlinElementTypeProviderImpl

Analysis API. Stubs and Decompilation

• KT-85371 StackOverflowError from LLKotlinStubBasedLibrarySymbolProvider and StubBasedClassDeserialization
• KT-83935 Support KDoc loading in decompiled stubs

Analysis API. Surface

• KT-82519 Automatically recognize the appropriate analysis mode for in-memory file copies based on their content
• KT-85239 Streaming version of collectDiagnostics()
• KT-83921 Extend KaKDocProvider to read Kdoc from KLIB metadata
• KT-77426 KaFirCompilerFacility uses an arbitrary JVM counterpart for common sources
• KT-84737 KaCallableSymbol#directlyOverriddenSymbols doesn't work for java overrides of kotlin properties
• KT-84621 Migrate symbol tests to ManagedTest properly
• KT-80575 KaFirJavaInteroperabilityComponent#getJavaGetterName should not throw exception on incomplete code

Backend. Wasm

• KT-76205 K/Wasm: stabilize and turn on incremental compilation by default
• KT-83728 [Wasm] Invalid Ir type while suspend call with blocked if null comprehansion
• KT-81637 K/JS/Wasm interop: Inconsistent behavior of is/as operations for JsReference<C> and C

Compiler

New Features

• KT-84484 Companion Extensions Analysis & Resolution
• KT-84298 K2: Generate IR for Companion Blocks & Extensions
• KT-84292 Enforce Companion Blocks & Extensions Language Feature during Resolution
• KT-84291 Companion Blocks & Extensions Checkers
• KT-84290 Callable References to Companion Block Declarations & Extensions
• KT-84287 Build Raw FIR for Companion Blocks & Extensions
• KT-73256 Implement all meta-target for annotations
• KT-84319 Add JVM target bytecode version 26
• KT-84297 Serialize & Deserialize Companion Block Declarations & Extensions to/from Metadata
• KT-84199 Implement DontMakeExplicitNullableJavaTypeArgumentsFlexible feature

Fixes

• KT-80489 Collection literals: experimental version (Frontend)
• KT-84566 Prevent launching Default dispatcher threads from IJ SDK in kotlin compiler
• KT-85358 Native: roll back the workaround for KT-84678 once MapLibre has been properly fixed
• KT-84931 Incorrect type nullability in SAM super type in anonymous class-based SAM conversion
• KT-83920 False positive "modifier 'value' is not applicable to 'local variable'" with soft keyword in positional destructuring (square bracket) declaration
• KT-85626 @JvmRecord in commonMain breaks compileCommonMainKotlinMetadata with "Cannot access 'java.lang.Record'"
• KT-52673 Don't report deprecation warning/error on imports
• KT-84991 Improve Argument type mismatch diagnostics
• KT-82216 Sanitize '.kotlin_module' filename
• KT-84678 K/N: Undefined symbol from SPM-added ObjC frameworks when linking iOS target
• KT-77726 Move FirUnusedExpressionChecker to the default checkers list
• KT-85354 checkPsiTypeConsistency: add psi text attachments
• KT-85479 Improve diagnostic messages for upper bound violations
• KT-84585 Upper bound violated warning for expansion of type alias in LHS
• KT-84924 Native: stdlib-cache.lock used by mulitple processes
• KT-85244 False positive DUPLICATE_BRANCH_CONDITION_IN_WHEN with guard condition
• KT-78432 No-arg constructor should be generated for regular classes with a value class parameter in case of JvmExposeBoxed
• KT-85487 Investigate why WrapContinuationForTailCallFunctions does not work in Android Test
• KT-59633 K2: Implement running AndroidRunner tests with FIR
• KT-85392 Native: concurrency issues in per-file caches
• KT-76237 Store File-level annotations in KLIB metadata separately
• KT-85162 Introduce diagnostics to refine numeric types casting
• KT-80060 False positive REDUNDANT_CALL_OF_CONVERSION_METHOD in case of overloads
• KT-85289 False-positive smartcast from == with type parameter based variable
• KT-83890 return-value-checker: false positive "Unused return value of 'context'" on kotlin.context() functions
• KT-84106 False negative "NON_EXHAUSTIVE_WHEN": "NoWhenBranchMatchedException" at runtime with sealed and platform type
• KT-85005 Consider all: target in the checker of repeatable annotations
• KT-85210 Enabling -XXLanguage:+IntrinsicConstEvaluation breaks highlighting on some broken code
• KT-85217 Rework implementation supporting simple-to-suspend function conversion
• KT-85036 Introduce a proper handling of optional expectation annotations in platform checkers during metadata compilation
• KT-85086 False-negative JVM_EXPOSE_BOXED_CANNOT_BE_THE_SAME
• KT-84082 [OPT_IN_USAGE_ERROR] duplicates for destructuring declaration
• KT-84732 Collection literals: "Expected FirCollectionLiteralImpl to be resolved" in RHS of equality operator
• KT-84841 Collection literals: Drop special treatment of when with expected type
• KT-85007 Properly implement special rules for kotlin.Result in @JvmExposeBoxed support
• KT-74383 Support new callable reference nodes in JVM backend
• KT-84828 Cleanup JVM backend from the old callable references-related code
• KT-85006 Refine error messages for INAPPLICABLE_ALL_TARGET diagnostic
• KT-84296 Support Companion Blocks in CFG
• KT-85058 Remove final field modification in DescriptorRendererOptionsImpl to prevent warnings on JDK 26+
• KT-85021 False positive SUBCLASS_CANT_CALL_COMPANION_PROTECTED_NON_STATIC error in multi-module project
• KT-84727 [K/N] Segfault when returning null as generic Int type from dynamic framework
• KT-85062 Deprecate language version 2.1
• KT-83460 Deprecation from @all:Deprecated is not propagated to property accessors/backing fields
• KT-84859 Skip deprecation phase for generic arguments in qualifier receiver of static call for companion block members and extensions
• KT-85050 [Swift Export] usage of inline classes with ref types crashes at runtime
• KT-84983 Type parameter annotations are lost for local functions
• KT-78800 Investigate FirMissingDependencySupertypeInQualifiedAccessExpressionsChecker
• KT-73945 K2 IDE: Duplicated inspections for redundant 'open' in interface member
• KT-84294 Ensure Context Sensitive Resolution works with Companion Blocks & Extensions
• KT-81675 Improve message for CONTEXTUAL_OVERLOAD_SHADOWED
• KT-84994 Rework optimization for companion extension resolution
• KT-81598 incorrect type mismatch error messages for generic calls with explicit type arguments
• KT-83587 K2: Missing null-check when using == on Short! and Byte! platform types
• KT-261 Can't specify function return type in a subclass

Compose compiler

New features

• c1bbb47 Started inferring the stability of all interfaces to be Stability.Unknown, expect for those explicitly marked as known stable.

Fixes

• b/504284805 Fix indentation for generated proguard mappings
• b/422193018 Fix applier inference for nested composables of different types.
• b/497751457 Prevent a $stable property from being added to any object.
• b/427530633 Do not infer a getter call as static across when it is defined in another file.
• b/427530633 Started using Stability.Runtime more broadly. Now, when an element depends on the stability of an internal or public class defined in another file, the element will no longer infer the stability of that class and will depend on the runtime stability of that class instead.

IR. Actualizer

• KT-84293 Expect Actual Matching for Companion Block Declarations & Extensions

IR. Inlining

• KT-85605 "Local delegated property has not delegate" exception when calling inline function containing delegated property in a lambda from within an inline lambda

IR. Interpreter

• KT-80804 Enable constant evaluation for more standard library
• KT-83514 Get rid of EvaluatedConstTracker

IR. Tree

• KT-79663 KLIB-based compilers: Promote partial linkage to "always on"
• KT-76934 Drop old IR parameter API
• KT-74763 Build: refactor ':compiler:backend.common' and ':compiler:ir.backend.common' modules

JVM. Reflection

• KT-85550 Reflection: KParameter.type.classifier returns boxed KClass for non-nullable primitive types
• KT-85285 Reflection: InvocationTargetException (UInt cannot be cast to Integer) when reading UInt annotation property via getter
• KT-85322 Reflection: KotlinReflectionInternalError when loading ProGuard-obfuscated code compiled before 2.3.20
• KT-84679 Reflection: confusing "Kotlin reflection is not yet supported for synthetic Java properties" for reference to Java enum's entries property
• KT-85025 KTypeParameter instances not equal to each other for the same type parameter in member specialization KFunction
• KT-85091 Reflection: "KotlinReflectionInternalError: Unsupported parameter owner: null" on attempt to get annotations of annotation constructor parameter
• KT-84382 Reflection: raw list in Java type is transformed to List instead of MutableList

JavaScript

Fixes

• KT-82395 Support top-level declarations from compiler plugins in JS incremental compilation
• KT-81787 KJS: Value class type lost when using JsExport on interface
• KT-85411 Fix conversionCombinations.kt tests for the JS target
• KT-72198 KJS: ES2015 interop with ValueClass
• KT-15101 js: Same callable references are not equal
• KT-84810 [K/JS] Callable references operator produces duplicates
• KT-85323 JsClass optimization doesn't work well for primitives
• KT-60651 KJS / ES6: init block and constructor are not called
• KT-84601 K/JS: KClass<> reference doesn't work in JS counterside as a new target in ES6 mode
• KT-85099 KotlinJS: JsPlainObject from the js-plain-objects plugin does not respect overrides
• KT-84615 KJS: Forbid @JsStatic on extension functions/properties
• KT-84633 Kotlin/JS: "Serializer for class not found" error when IR output granularity is whole-program
• KT-85038 Kotlin/JS: @JsExport on sealed external interface with companion object causes NPE
• KT-85047 Kotlin/JS: @JsStatic on suspend fun of class companion generates incorrect d.ts
• KT-84517 K/JS: bad mappings data in outputted Kotlin stdlib source map

Klibs

• KT-84415 Ineffective hashMap usage in IrSymbolDeserializer
• KT-84511 [Native][Tests] Improve descriptor-related logic in NativeCliBasedFacades.kt
• KT-85017 [PL] Add test for added internal abstract fun
• KT-84488 Export in previous version: Prohibit using on 2nd stage
• KT-85149 Klib Dump parser: fix parsing of qualified names adjacent to vararg symbol
• KT-85129 Klib Dump parser: fix enum names parsing
• KT-84684 Remove UserVisibleIrModulesSupport from IR linker
• KT-84820 [K/N] Load libcallbacks and libllvmstubs from configured path

Language Design

• KT-73821 Decide the future of the ForbidUsingSupertypesWithInaccessibleContentInTypeArguments language feature
• KT-80852 Version overloading: generate overloads corresponding to different versions of a function whose parameters are annotated with @IntroducedAt(<version>)
• KT-85120 @IntroducedAt on expect parameter cannot be properly actualized

Libraries

• KT-85122 Deprecate kotlin.io.readLine with WARNING
• KT-84970 Deprecate AbstractCoroutineContextKey and associated API
• KT-84818 [Regex] Native and Wasm: Decomposed Unicode character are incorrectly process with CANON_EQ flag
• KT-80772 K/N: Regex: improve look behind matching performance for "fixed-length" patterns
• KT-81395 Stabilize kotlin.uuid.Uuid API
• KT-85127 Remove kotlin.test.assert*NoInline hidden functions
• KT-84264 Add appropiate @SinceKotlin to new contracts
• KT-84921 Add 'returnsResultOf' contract to appropriate declarations in the stdlib
• KT-84697 Update the list of JDKs the stdlib is tested with

Native

• KT-83914 Native: when loading JNI libraries, java.library.path can contain system directories with libraries with same names
• KT-84826 Bump the minimum deployment version of Apple targets
• KT-83133 Native: don't use sun.misc.Unsafe in the compiler and cinterop when running on JDK 25+
• KT-84686 Removing x64 in gradle file breaks builds on certain platforms
• KT-83648 Native: don't use sun.misc.Unsafe in NativeMemoryAllocator when running on JDK 25+
• KT-83647 Native: don't use sun.misc.Unsafe in nativeMemUtils when running on JDK 25+

Native. Build Infrastructure

• KT-85191 K/N: Dependency cycle in libclangInterop
• KT-84937 Kotlin/Native: non-reproducible .bc for mingw_x64

Native. C Export

• KT-61748 KMM- warnings when compiling native targets (Kotlin 1.9.0)

Native. C and ObjC Import

• KT-85705 Swift-generated headers with external_source_symbol produce duplicate enum declarations
• KT-85399 Kotlin/Native: TypeCastException when casting ObjC Protocol MetaClass with genericSafeCasts enabled
• KT-85508 K/N: TypeCastException when using nw_parameters_create_secure_tcp block parameter on 2.3.20
• KT-84023 Modular import fails with an obscure error when the failing module is not the last one

Native. ObjC Export

• KT-85171 Red Swift code in Native UI Multiplatform App project from Template Gallery

Native. Runtime

• KT-84331 Kotlin/Native: RunLoopFinalizerProcessor needs initialized runtime before it has any jobs

Native. Runtime. Memory

• KT-83670 K/N: gc concurrent mark phase assert Failed to terminate mark in STW in a single iteration

Native. Swift Export

New Features

• KT-82705 Support convenient export of Flow types in Swift export
• KT-85130 [Swift Export] Preserve TypeInfo on SharedFlow
• KT-84361 [Swift Export] Preserve TypeInfo on StateFlow

Fixes

• KT-84317 Swift Export: "protocol members can only be marked unavailable in an '@objc' protocol" in generated code for kotlinx-coroutines
• KT-85380 [Swift Export] Attempt to bridge unbridgeable type: SirUnsupportedType
• KT-85704 [Swift Export] cannot infer generic type of function returning a generic type
• KT-85711 [Swift Export] suspend function returning non-null generic fails to compile
• KT-85715 [Swift Export] generic interface in typealias fails to compile
• KT-85714 [Swift Export] unsupported input type param in functional receiver
• KT-85458 [Swift Export] value of a closure returning a closure generates invalid swift code
• KT-85521 [Swift Export] conflicting overloads for generated Kotlin bridges
• KT-85293 SwiftExportCoroutinesWithResultValidationTest.testCoroutines fails after cross-push
• KT-84515 [Swift Export] suspend functional parameter generates invalid Swift code
• KT-82282 Swift Export: suspend function returning Array leads to incompilable code
• KT-81540 Swift Export: using interface in Set generates incompilable code
• KT-80305 Support coroutines in Swift Export
• KT-66873 Swift Export: suspendable contravariant functional type
• KT-85272 [Swift Export] conflicting imports for kotlinx-coroutines
• KT-85163 [Swift Export] Flow of Unit values crashes
• KT-85159 [Swift Export] Flow is not properly being cancelled
• KT-84226 [Swift Export] Flow in contrvariant position is not allowed
• KT-84485 [Swift Export] Flow with nullable elements
• KT-83730 Generated Swift switch on bridged Kotlin enum crashes with fatalError
• KT-85016 [Swift Export] it's not OK to expose Flow as AsyncSequence
• KT-84979 Swift Export Nullability: Unit
• KT-83821 Swift Export: suspend function returning Nothing leads to incompilable code

Tools. BCV

• KT-83476 Use Maven publications as dump input [ABI Validation]

Tools. Build Tools API

New Features

• KT-82791 BTA: introduce an option for ExecutionPolicy.WithDaemon to control the daemon log files path
• KT-80963 BTA: Add structured information about reported messages to KotlinLogger
• KT-73037 Add input (like compiler arguments) changes tracking

Fixes

• KT-84228 BTA: Improving KDoc generation for Enums and Custom Types
• KT-85738 BTA forward compatibility: NoSuchFieldError on X_IGNORED_ANNOTATIONS_FOR_BRIDGES when API 2.3.0 is used with impl 2.4.0
• KT-85082 Make Xignored-annotations-for-bridges type safe
• KT-82390 [BTA] Remove deprecated non-builder factory functions and classes
• KT-85072 AbstractMethodError when calling discoverScriptExtensionsOperationBuilder with pre-2.4.0 compiler
• KT-85447 BTA: deprecate JvmCompilerArguments.contains (warning)
• KT-85092 [BTA] Update BTA Backward Compatibility Testing: 2.3.20-RC → 2.3.20
• KT-85439 BTA: Warn or error when incompatible compiler arguments are passed via applyArgumentStrings
• KT-75540 Build Tools API Should Reject -Xbuild-file Argument
• KT-85391 [BTA] Hide boilerplate required to load isolated BTA implementation
• KT-80679 Add support for the Build Tools API [ABI Validation]
• KT-85035 Don't expose X_COMPILER_PLUGIN_ORDER in CommonCompilerArguments
• KT-84738 Make Xscript-resolver-environment type safe
• KT-85204 Make Xdump-directory type safe
• KT-85205 Make Xdump-perf type safe
• KT-85069 Make Xnullability-annotations type safe
• KT-85167 Make Xjsr305 type safe
• KT-85094 Make Xwarning-level type safe
• KT-85294 BTA: Replace hardcoded @since in KDoc with dynamic versioning
• KT-85333 Add BTA tests for BACKUP_CLASSES and KEEP_IC_CACHES_IN_MEMORY behavior after compilation error
• KT-84770 BTA: default options cannot be retrieved from many option objects
• KT-85224 Add @ExperimentalArgumentApi to compiler argument DSL types
• KT-84322 Make X_PROFILE BTA compiler argument type safe
• KT-84953 Fail TC build if generated files change
• KT-85189 Refactor path argument types: flatten hierarchy and improve naming
• KT-84984 Runtime NPEs caused by null return in CompilerMessageRenderer implementation
• KT-84015 Introduce detection of custom script names to new BTA API

Tools. CLI

• KT-85414 Argument DSL: delimiter = KotlinCompilerArgument.Delimiter.PathSeparator generates invalid Kotlin code
• KT-85001 Convert ImplicitJvmExposeBoxed language feature to analysis flag
• KT-84999 Don't poison binaries with ImplicitJvmExposeBoxed language feature
• KT-85004 Set proper since version for language feature about property annotation targeting
• KT-56850 Separate K/Wasm CLI entry point from K/JS CLI

Tools. Compiler Plugin API

• KT-85133 Drop deprecated K1 specific methods from IrPluginContext

Tools. Compiler Plugins

• KT-75656 PowerAssert: Create runtime library
• KT-75873 PowerAssert: display callable reference value under '::'
• KT-85151 PowerAssert: Surround string and character values with quotes
• KT-85184 PowerAssert: Annotation may only be used on expect and non-override functions
• KT-69036 Power-Assert indent multiline values
• KT-85089 PowerAssert: Wasm CompileError when using PowerAssert.explanation

Tools. Gradle

New Features

• KT-76197 Write Kotlin compiler warnings and errors to Problems API

Fixes

• KT-85412 Module name is not sanitized with older Kotlin compiler versions
• KT-65566 Use the new ConfigurationContainer consumable method to create consumable configurations
• KT-85509 Remove deprecated API in the 2.4.0 release
• KT-83858 Compatibility with Gradle 9.4.0 release
• KT-69830 Support Gradle com.gradle.develocity plugin in KGP
• KT-85433 Gradle: deprecate non-BTA JVM compiler execution mode
• KT-80448 Remove internal & deprecated API from ExtrasProperty.kt
• KT-69701 Gradle: module name is passed inconsistently to different types of compilations
• KT-83860 Run tests against Gradle 9.4.0
• KT-83859 Compile against Gradle API 9.4.0
• KT-84729 Update Gradle plugin-publish version to enable configuration cache badge on Gradle plugins portal

Tools. Gradle. BCV

• KT-83999 ABI validation: Groovy DSL doesn’t deprecate included/excluded filters, allowing four filter configs instead of two
• KT-84461 Remove the use of abi-tools-api from KGP [ABI Validation]
• KT-84100 Add Deprecated annotation to legacyDump block and property [ABI Validation]

Tools. Gradle. Compiler plugins

• KT-85343 Update Compose Gradle plugin deprecations before 2.4

Tools. Gradle. JS

• KT-84753 Deprecate KotlinJsCompilerType and KotlinProjectExtension methods using it
• KT-81033 K/JS, Wasm: Remove deprecated wasm declarations in "js" package
• KT-81034 K/JS, Wasm: Remove deprecated public constructors of JS declarations
• KT-81030 K/JS, Wasm: remove deprecated NodeJsExec.create
• KT-81037 K/JS, Wasm: Remove deprecated internal JS functions

Tools. Gradle. Multiplatform

• KT-84767 K/N: associateWith triggers warning about friend-modules libs not included in -library argument
• KT-69571 compileNativeMainKotlinMetadata not handling project/prebuilt substitutions
• KT-84533 KMP: compileCommonMainKotlinMetadata: "Unresolved reference" for androidx.savedstate from Maven (works with project() dependency)
• KT-84669 SPM import: If iosApp dir located outside of the project, checkSyntheticImportProjectIsCorrectlyIntegrated will fail
• KT-84085 Remove deprecated gradle property kotlin.kmp.isolated-projects.support
• KT-84597 Remove trailing comma for dependencies blocks settings in Package.swift
• KT-82895 kotlin-stdlib import is flaky in commonTest in 2.1.21

Tools. Gradle. Native

New Features

• KT-83873 Redo how dynamic library linkage and promotion are handled

Fixes

• KT-69896 Native: output to stderr ends up in the Gradle log
• KT-85708 [KGP] dSYM copy task ignores isStatic due to eager read before framework configuration
• KT-84262 integrateEmbedAndSign produces an incorrect Gradle call for the root project
• KT-84730 Add Kdocs to SwiftPM import APIs
• KT-85502 Swift PM Import: "Library not loaded": KotlinMultiplatformLinkedPackage.framework is not copied next to the executable
• KT-85510 Cleanup native tasks API
• KT-82824 Make linker hack path relative
• KT-85128 Refactor SwiftPM import lock tests and test utils
• KT-83874 Linker hack doesn't work when clang uses response files
• KT-83681 Parallelize parts of SwiftPM import pipeline that are called during import

Tools. Gradle. Wasm

• KT-85046 K/Wasm: Wasm per-module Gradle integration tests on Windows

Tools. Incremental Compile

• KT-85387 BTA: switch the default value of MONOTONOUS_INCREMENTAL_COMPILE_SET_EXPANSION to true
• KT-85386 BTA JVM IC: 'moduleName' is null!
• KT-84450 Star imports are not reported via FirImportTrackerComponent

Tools. JPS

• KT-81579 JPS: -Xwarning-level=DEPRECATION:warning not supported

Tools. Kapt

• KT-32743 Kapt, Maven: Do not include compile classpath entries in the annotation processing classpath
• KT-41217 Running kapt with Maven does not seem to include the compilation classpath

Tools. Maven

• KT-84386 Support Maven Toolchains in kotlin-maven-plugin
• KT-76062 Maven: remove Kotlin script execution support
• KT-85317 Auto‑align jvmTarget with the project’s Java level
• KT-84101 Maven: compile and test-compile handle sourceDirs inconsistently
• KT-84653 Add integration test for KAPT with smart defaults in mixed Kotlin+Java projects
• KT-85121 Maven: enable configuration inputs tracking in BTA
• KT-84778 Add integration test for auto-bind execution order in mixed Kotlin+Java projects
• KT-85146 Maven: Adding stdlib as smart-default may break maven dependency resolution for other plugins
• KT-83109 Remove beanshell and groovy verification in kotlin-maven-plugin-test

Tools. REPL

• KT-77816 REPL: Support for const properties
• KT-84483 [K2 Repl] NullPointerException in Analysis when using custom classes
• KT-84803 [REPL] FirReplSnippet: provide the eval function symbol instead of the name (evalFunctionName)

Tools. Scripts

• KT-85105 Scripts: JVM backend internal error (IR lowering) when scratch file contains anonymous object
• KT-85103 Exception while generating code when explain destructuring decls
• KT-85029 Kotlin Scripting: ScriptDiagnostic reports "at null" instead of error location

Tools. Statistics (FUS)

• KT-85628 KGP: composite build FUS metrics fail on access of 'configurationTimeMetrics'

Tools. Wasm

• KT-75086 Wasm: Deprecate and remove D8 in js packages

Changelog

Analysis API

• KT-83867 OVERLOAD_RESOLUTION_AMBIGUITY false positive with assertEquals in IJ repo
• KT-83723 [Analysis API] Enable experimental KDoc resolver by default
• KT-83388 Analysis API: properly support KMP in KotlinPackageProvider

Analysis API. Code Compilation

• KT-78946 Evaluation of variable with local class in type parameter leads to InventNamesForLocalClasses exception

Analysis API. FIR

• KT-84711 K2 IDE sometimes loses FIR plugin-generated declarations after file changes
• KT-84596 Improve K2 Jooq completion performance
• KT-84525 KaValueParameterSymbol#getHasSynthesizedName returns false for FirDeclarationOrigin.SubstitutionOverride.DeclarationSite
• KT-68260 K2 AA: InvalidFirElementTypeException “For CALLABLE_REFERENCE_EXPRESSION with text ::lam1, unexpected element of type: no element found” with illegal callable reference call
• KT-83546 Kotlin analysis reach ClsCustomNavigationPolicy
• KT-84259 Move CommonDefaultImportsProvider to the frontend independent module
• KT-82945 Analysis API: KotlinIllegalArgumentExceptionWithAttachments: Expected FirResolvedTypeRef with ConeKotlinType but was FirUserTypeRefImpl
• KT-71135 AA: exception from sealed inheritors checker when analyzeCopy

Analysis API. Infrastructure

• KT-84776 The test data manager misses the redundancy check in the update mode
• KT-84962 The test data manager misses -ea flag
• KT-84388 Preserve the EOF status in the test data manager to avoid extra changes
• KT-83905 Analysis API: Improve UX with test data
• KT-84362 Analysis API tests produce many warnings due to "not yet loaded registry"
• KT-84279 Test Data Manager fails on a clean build
• KT-83913 Exclude compiler-based Analysis API tests from Git tracking
• KT-80379 Extract per-module test generators for AA tests
• KT-84120 Move CLI modules out of kotlin-compiler-fe10-for-ide
• KT-83200 Track external dependencies of the Analysis API modules

Analysis API. Light Classes

• KT-82434 Light classes should prefer enum entries to properties
• KT-84200 SLC: return type is not boxed for delegated methods with generic original method
• KT-72451 "CCE: class PsiPrimitiveType cannot be cast to class PsiClassType" with same-named enum class and typealias

Analysis API. PSI

• KT-83846 Set up guidelines for PSI
• KT-84135 Deprecate KtSelfType

Analysis API. Providers and Caches

• KT-82731 Analysis API: Limit granular tree change processing to a few files
• KT-79234 Analysis API: Usage of asMap() on Caffeine caches bypasses stats counters
• KT-74090 Analysis API: Support dumb mode (restricted analysis)

Analysis API. Standalone

• KT-83801 Nested typealiases are not correctly indexed in standalone mode

Analysis API. Surface

New Features

• KT-73534 SAM method API
• KT-82993 Support explicit backing fields in the Analysis API

Fixes

• KT-84397 KtDefaultAnnotationArgumentReference should return only results with value name
• KT-84804 buildSubstitutor does not work correctly with Java type parameters
• KT-84389 Cover references with ABI and documentation checks
• KT-57042 K2, Analysis API: KaJavaInteroperabilityComponent#callableSymbol returns null for a Java getter implementing Kotlin property
• KT-80856 Analysis API: analysisContextModule incorrectly determines the module of an original file when used for dangling file context assignment
• KT-84363 AA, isUsedAsExpression: Unhandled Non-KtExpression parent of KtExpression: class org.jetbrains.kotlin.psi.KtContractEffect
• KT-70476 Analysis API: "KtDefaultAnnotationArgumentReference.resolveToSymbols" does not work in FIR implementation
• KT-68499 Split KtDefaultAnnotationArgumentReference on K1 and K2 implementation
• KT-70521 Analysis API: Impossible to distinguish between 'iterator' operator calls dispatched with imports from objects
• KT-77669 Context arguments are missed on implicit invoke calls
• KT-77670 resolveToCall: extensionReceiver is incorrectly chosed due to a conflict with context parameters for an implicit invoke call
• KT-68633 K2 AA: IAE "Expected class KaClassSymbol instead of class KaFirEnumEntrySymbol" with enum entry initializer
• KT-79186 KtCompletionExtensionCandidateChecker does not work for extensions when using callable references of a type
• KT-83777 Analysis API: The resolution scope of a context module accepts elements from associated dangling files
• KT-82571 No expected type for overridden property without explicit type
• KT-83759 Analysis API: Mark platform interface APIs with @KaPlatformInterface
• KT-83223 Support "Explicit context arguments" in the Analysis API
• KT-65186 K2: Analysis API: KtExpressionTypeProvider.getExpectedType works incorrectly for the right hand side of assignment expressions
• KT-76011 KaFirNamedClassSymbol#companionObject doesn't provide generated objects generated by compiled plugins
• KT-73290 Analysis API: Improve the architecture of content scopes and resolution scopes

Backend. Native. Debug

• KT-83804 Native: debug information generator converts relative paths to absolute ones

Backend. Wasm

• KT-83162 K/Wasm: renaming temporary and synthetic variables in the Chrome debugger
• KT-85008 Develop and publish a demo app using an early version of the component model support
• KT-65030 K/Wasm: memory allocator for Component Model ABI
• KT-83607 WasmJS: Production build eliminates 'else if' branch when 'else' is not wrapped with curly braces
• KT-83728 [Wasm] Invalid Ir type while suspend call with blocked if null comprehansion
• KT-82803 Kotlin/WASM: Failed to compile the doResume function with if inside catch block
• KT-83800 [Wasm] Closed world per-module compilation

Compiler

New Features

• KT-84319 Add JVM target bytecode version 26
• KT-83165 Collection literals: treat Deprecated(HIDDEN) operators of reasonably
• KT-84487 "-Xcollection-literals" compiler flag
• KT-84072 Collection literals: treat visibility of of during resolve correctly
• KT-80500 Collection literals: Analyze ConeCollectionLiteralAtom in cases their expected type is not fully known
• KT-80491 Implement fallback mechanism for collection literals
• KT-80490 Implement overload resolution mechanism for collection literals
• KT-84484 Companion Extensions Analysis & Resolution
• KT-84199 Implement DontMakeExplicitNullableJavaTypeArgumentsFlexible feature
• KT-83765 Make -Xsuppress-version-warnings have a diagnostic ID
• KT-84288 Companion Blocks Analysis & Resolution
• KT-84287 Build Raw FIR for Companion Blocks & Extensions
• KT-84286 Parse Companion Blocks & Extensions
• KT-66344 K1 & K2: False positive WRONG_NUMBER_OF_TYPE_ARGUMENTS in callable reference to inner class member
• KT-76766 Warning is missing for wrong subclass checking
• KT-74049 Introduce special override rule to allow overriding T! with T & Any

Performance Improvements

• KT-84412 iOS release build time dramatically increases with 2.3.20-Beta2 compared to 2.3.10
• KT-80367 Reduce memory consumption of DevirtualizationAnalysis
• KT-82559 linkDebugTest*X64 tasks are slower for Kotlin 2.3 than for 2.2
• KT-84095 Improve Unit tail-call optimization to support inline generic functions similar to suspendCoroutine

Fixes

• KT-84559 @OptIn on collection literal and context-sensitive does not work
• KT-84675 Collection literals: 'Not singleClassifierType superType: TypeVariable(S)' in PCLA
• KT-84547 Collection literals: "Expected expression 'FirCollectionLiteralImpl' to be resolved" in elvis expression
• KT-83920 False positive "modifier 'value' is not applicable to 'local variable'" with soft keyword in positional destructuring (square bracket) declaration
• KT-84190 Implement basic functionality for returnsResultOf contract
• KT-85058 Remove final field modification in DescriptorRendererOptionsImpl to prevent warnings on JDK 26+
• KT-72710 Incorrect behaviour of tail call suspend functions optimization
• KT-80590 Drop language version 1.9 for JVM
• KT-83904 [Inliner] Inline function overrides an abstract method with a default value in an inheritance chain
• KT-77584 Support scripts built from LT in scripting API
• KT-84185 Type arguments are wrongly allowed in receivers of static calls
• KT-83441 False positive: REDUNDANT_CALL_OF_CONVERSION_METHOD
• KT-83587 K2: Missing null-check when using == on Short! and Byte! platform types
• KT-84860 False positive UNINITIALIZED_ENUM_COMPANION in enum access with explicit receiver in enum initializer when enum class has a companion
• KT-84405 ClassCastException with conflicting projection on the LHS of a callable reference
• KT-84866 Reserve CoroutineContext as context parameter for future use
• KT-84717 Provide information for qualified expressions that might be replaced with context-sensitive simple names in IDE mode
• KT-65239 K2: Render FIR declaration instead of IR-based descriptors in IR signature clash diagnostics
• KT-84743 Type parameter declared as 'in' can be used in 'out' position in DNN & flexible types
• KT-84720 "Unused return value" is not reported inside used if/when multi-statement blocks
• KT-84198 Support multiple embedded .let-like calls with returnsResultOf contract
• KT-84310 No Warning Emitted For Deprecated Java Enum Value Usage
• KT-81871 Drop context receiver tests
• KT-80113 Consider improving diagnostic messages related to ==/===/is/as
• KT-84714 KJS: Forbid exporting properties with context parameters
• KT-84380 Type alias to non-generic class can have (arbitrary number of) type arguments in LHS of ::class
• KT-84366 Invalid name for captured this in bytecode
• KT-80701 Native: -Xbinary=cCallMode is not integrated with compiler caches
• KT-84000 Native: test pre-codegen inliner on CI
• KT-57557 Implement getAndSet for AtomicNativePtr via getAndSetField intrinsic
• KT-84352 createUninitializedInstance generates invalid LLVM for value classes
• KT-84411 Confusing message for the class reference of the inner class with the type parameter
• KT-84280 Standalone Unit qualifier allows type arguments: Unit<Any>
• KT-84281 Standalone typealias-to-object qualifier allows type arguments and has type Unit in this case
• KT-84594 EBF is smartcasted in inline function with @PiblishedApi
• KT-83938 Missing Tail call optimization in reference classes returning Unit
• KT-83989 Update coroutines-codegen.md after changes of Unit tailcall optimization
• KT-83988 Remove extraneous POP+GETSTATIC Unit for calls of Unit-returning suspend functions
• KT-80925 Replace "useless" in diagnostic messages
• KT-83646 Native: don't use sun.misc.Unsafe in ByteArrayStream when running on JVM 24+
• KT-82122 Prohibit arbitrary placement of type parameters in callable reference LHS
• KT-82574 Fixation: consider preferring EQUALS constraints to LOWER ones
• KT-83564 Consider dropping HAS_PROPER_NON_NOTHING_NON_ILT_LOWER_CONSTRAINT
• KT-84213 Flaky incremental compilation behaviour with EBF
• KT-84133 Adopt initInstance to handle value classes
• KT-24840 Square bracket escaping in KDoc
• KT-82123 KDoc: references that goes after markdown blocks don't have links
• KT-84196 Handle multiple entry/exit points for returnsResultOf functions
• KT-84195 Handle function references in returnsResultOf
• KT-84167 Invalid type references with type arguments in package parts compile without diagnostics
• KT-37179 false-positive shadowing warning on local and member extension functions in presence of member extension property with invoke operator
• KT-84209 False negative ACTUAL_ANNOTATIONS_NOT_MATCH_EXPECT on context parameters of function types
• KT-83354 Wrong position for lambda context type error
• KT-84206 Remove forcesPreReleaseBinaries = true from ExplicitBackingFields
• KT-83524 An anonymous function with named parameters throws FileAnalysisException
• KT-84155 K2: NO_CONTEXT_ARGUMENT caused by stale value in NewConstraintSystemImpl.hasContradictionInForkPointsCache
• KT-83829 False-negative INVALID_DEFAULT_FUNCTIONAL_PARAMETER_FOR_INLINE
• KT-83842 KIAEWA: Exception in expression checkers for @OptIn(markerClass=[…])
• KT-84045 Evaluate default arguments of annotation's parameters using FIR evaluator
• KT-70562 @SubclassOptInRequired cannot accept multiple experimental marker
• KT-83987 Refactor/fix CoroutineCodegen.isReadOfInlineLambda()
• KT-83772 Create a language feature for wrapContinuationForTailCallFunctions
• KT-84061 K2: IllegalStateException: FirResolvedNamedReference expected on plusAssign for array element with unresolved initializer inside buildList
• KT-83985 Drop arrayOf check from EscapeAnalysisChecker after bootstrap update
• KT-78885 Current frame disappears from stack trace when debugging inline-heavy suspend code
• KT-78727 Split KonanConfig into NativeFrontendConfig and NativeBackendConfig
• KT-83755 Support rendering of evaluated and original arguments in FirAnnotationRenderer#renderAnnotation
• KT-17763 Inner class constructor has incorrect generic signature in the bytecode
• KT-83625 Initialize annotations on Java record components
• KT-83795 Compiler crash on suspend lambda as default parameter of inline function
• KT-72880 Calls with incorrect VarHandle method signatures are generated with -Xjdk-release being used
• KT-67809 Native: remove support for non-opaque LLVM pointer types
• KT-82148 Suspend function returns the wrong value and not Unit
• KT-55559 JVM: ClassCastException with Unit returning suspend function and tail-call Non-Unit returning suspend function and callable reference
• KT-70995 Kotlin/Native: Treat all @HasFinalizer types as escaping in Escape Analysis
• KT-83903 'when' with 'val' does not take previous nullability check into account
• KT-83952 StackEntries for tail-call suspend functions have internal names for classes instead of FQ names
• KT-83377 Investigate usage of declarationSymbols in resolve of local user type
• KT-83770 Smartcast doesn't work for an explicit backing field with multiple intersections
• KT-83650 Native: don't use sun.misc.Unsafe in CastsOptimization when running on JVM 24+
• KT-83754 KotlinIllegalArgumentExceptionWithAttachments for explicit backing field with annotated type
• KT-83756 Error while resolving FirNamedFunctionImpl with explicit backing field and implicit type
• KT-83563 Consider dropping fixation readiness REIFIED
• KT-83713 K2: No error with external primary constructor parameter
• KT-83104 K2: No error with external enum entry
• KT-83696 Consider dropping HAS_NO_RELATION_TO_ANY_OUTPUT_TYPE readiness
• KT-83308 K/N: "IllegalArgumentException: An interface expected but was Any"
• KT-81590 Switch latest stable version in Kotlin project to 2.4
• KT-66701 K2: Java interface method override via Kotlin class rejected
• KT-56563 Inference within if stops working when changing expected type from Any to a different type

IR. Inlining

• KT-84112 Intra-module inliner: No container found for type parameter 'T'
• KT-84416 High memory usage for IrFileEntry after enabling inliner
• KT-75396 [IR] Pass LoweringContext to inline and serialization checkers
• KT-73708 Use some marker in KLIBs produced with IR inliner

IR. Interpreter

• KT-84561 K2: Convert evaluated constant by default in FIR2IR

IR. Tree

• KT-79663 KLIB-based compilers: Promote partial linkage to "always on"
• KT-76634 PL: Don't report warnings in cases that don't lead to runtime errors
• KT-72950 Partial Linkage: Change the semantics of -Xpartial-linkage-loglevel
• KT-79801 KLIBs: Implement checks for symbols loaded by the compiler on 1st and 2nd phases
• KT-72812 IR serializer: Don't serialize any cinterop fake overrides to Klibs

JVM. Reflection

• KT-85091 Reflection: "KotlinReflectionInternalError: Unsupported parameter owner: null" on attempt to get annotations of annotation constructor parameter
• KT-84796 Reflection: mutable flexibility is lost for K1-based types in KClass.allSupertypes
• KT-84494 Reflection: Java Collections have differences in kotlin supertypes from old K1 reflection
• KT-84382 Reflection: raw list in Java type is transformed to List instead of MutableList
• KT-84492 Reflection: supertypes of raw list in Java type are not raw
• KT-84076 Reflection: list in Java type is transformed to flexible instead of mutable list
• KT-14990 'callBy' for inner class constructor fails at run-time
• KT-82881 Reflection: update KCallable.callBy kdoc to mention vararg parameters
• KT-84075 Reflection: wildcard in Java type is transformed to out Any! instead of star projection
• KT-82659 Reflection: IAE on a call to a Java inner class constructor

JavaScript

New Features

• KT-51292 Proposed behavior of @JsExport on interfaces and classes with companion objects
• KT-82128 [K/JS] Allow named companion objects in exported interfaces
• KT-21626 Support ES2015 syntax in js function
• KT-83452 K/JS: Support ES6 array destructuring in js() calls
• KT-83451 K/JS: Support ES6 object destructuring in js() calls

Performance Improvements

• KT-77646 KJS: optimize Byte/Char/Short/Int/Float/DoubleArray.copyOf(newSize)

Fixes

• KT-84002 Bump version from 2.3 to 2.4 for JsNoRuntime-related annotations
• KT-84090 Save variance in the generated TypeScript
• KT-84332 KJS: Reconsider disallowing nested classes in exported interfaces
• KT-56618 KJS/IR: Support external interfaces from common code (via annotation?)
• KT-84474 Kotlin/JS: Long::class becomes null when passing the value to a generic function with -Xes-long-as-bigint
• KT-83701 Escaped identifier with a quote cause an invalid d.ts file
• KT-84647 K/JS: Class expressions are not supported in js() calls
• KT-68281 K/JS: Order of classes in initMetadataForClass are not deterministic
• KT-84458 KJS: Fully support @JsStatic in Analysis API-based TypeScript Export
• KT-84454 KJS: Generate protected overrides for abstract class inheritors in Analysis API-based TypeScript Export
• KT-84490 KJS: Fix mutability of exported top-level variables Analysis API-based TS export with ES modules
• KT-84459 KJS: Support default exportability in Analysis API-based TypeScript Export
• KT-84456 KJS: Support deprecation comments in Analysis API-based TypeScript export
• KT-82264 Implement exporting classes in Analysis API-based TypeScript Export
• KT-84233 K/JS: exported collection views doesn't provide Iterator methods
• KT-82127 Remove generator-based coroutines intrinsics after bootstrap
• KT-84003 Remove @Suppress from JsReference after bootstrap
• KT-44753 KJS / IR: @JsExport non-public fun exports nothing
• KT-83992 Drop K1 JS entry point and IC code
• KT-69353 KJS / d.ts: Kotlin does not export base collection classes along with their mutable collection counterparts

Klibs

Performance Improvements

• KT-84451 [Klib] Use varint encoding for element sizes in IR tables
• KT-80903 [Klib] Optimize size of serialized IR element coordinates
• KT-84400 [Klib] Optimize size of serialized IrExpression
• KT-79675 K/N: Uncached ZipFIleSystemAccessor

Fixes

• KT-82471 [K/N] Klib forward compatibility testing with codegen tests
• KT-83807 Restore non-nullability of symbols not available in 2.3.0 stdlib
• KT-83929 Add tests for IR signatures of static properties and functions
• KT-83012 Export in previous version (Native): add the checker for incompatible Kotlin stdlib/compiler pairs
• KT-82469 [K/N] Klib backward compatibility testing with codegen tests
• KT-84341 Fix detection of box function in forward compatibility tests
• KT-81411 Merge KonanLibrary to KotlinLibrary to simplify adoption of KlibLoader in the Kotlin/Native compiler
• KT-83748 Bump versions in JS Klib compatibility testing
• KT-78188 [JS] Klib backward and forward compatibility testing
• KT-83724 Fix & unmute stdlib & kotlin-test compatibility tests
• KT-83151 Restore non-nullability of symbols available since 2.3

Language Design

• KT-80852 Version overloading: generate overloads corresponding to different versions of a function whose parameters are annotated with @IntroducedAt(<version>)

Libraries

New Features

• KT-73111 No UInt.toBigInteger() and ULong.toBigInteger() conversion function
• KT-78499 Add isSorted() extension to standard library

Fixes

• KT-83956 Clarify joinToString behavior when the receiver is empty
• KT-71848 Kotlinx.metadata: Add CompilerPluginData into Km API
• KT-61180 kotlin.ArrayIndexOutOfBoundsException on Native with Regex, works on Android/JVM though
• KT-84871 compareValues, nullsFirst, nullsLast return 0 for -0.0 and 0.0 on JS
• KT-84691 Add samples for toBigInteger extension functions
• KT-84372 PathExtensionsTest.copyToRestrictedReadSource fails with JDK22+
• KT-84369 StringJVMTest.formatter fails with JDK13+
• KT-84613 String.toDouble() produces incorrect results on Wasm for large exponent values
• KT-76905 Add samples for kotlin.math functions
• KT-84355 Reduce the number of iterations for the removeHashAtStressTest
• KT-83962 List.listIterator(Int) KDoc's exception condition is incorrect
• KT-83958 Improve enumValueOf documentation
• KT-83953 Add samples for kotlin.time extension functions
• KT-83951 Rewrite stdlib samples to use assertPrints instead of assertEquals

Native

• KT-84826 Bump the minimum deployment version of Apple targets
• KT-78686 LLVM update Q1 2026
• KT-82674 Native: dyld[...]: Symbol not found: _mach_vm_reclaim_update_kernel_accounting_trap on macOS
• KT-81748 Create a phased CLI for Native klib compilation
• KT-82879 Native: DLLs in the Windows distribution are not reproducible
• KT-83283 Test Kotlin/Native performance tests compilation in Gradle 9.0
• KT-82872 Native: make Kotlin/Native distribution compiler cache reproducible for Linux
• KT-82871 Native: cstubs.bc for android_* platform libraries contain absolute paths in string literals
• KT-34467 Cinterop: Clang crashes when -fmodule-map-file is specified (SIGSEGV)

Native. Build Infrastructure

• KT-80072 Make Kotlin/Native distribution reproducible
• KT-81771 konanc failing to load native libraries
• KT-84503 Duplicate META-INF/serialization.shadow.kotlin_module entry in kotlin-native-compiler-embeddable jar

Native. C and ObjC Import

• KT-81433 Generate C-interop KLIBs in previous ABI version in Kotlin 2.4.0
• KT-82766 K/N: external_source_symbol clang attribute causes cinterops with -fmodules to downgrade to forward declaration
• KT-82402 Inter-cinterop type reuse with -fmodules uses forward declaration when an actual declaration is available
• KT-82377 Fix ObjC forward declaration handling in modular cinterops
• KT-81695 Repeated typedefs across multiple clang modules break cinterop with -fmodules
• KT-81752 Native: investigate and remove filtering of -fmodule-map-file in cinterop
• KT-82379 Introduce lenient modular cinterop mode
• KT-83814 Native: includedHeaders= in platform libs manifests is not reproducible when modules= is used

Native. Runtime. Memory

• KT-80770 Kotlin/Native: revise ObjC refcount methods called in runnable state
• KT-84640 Native: comment for kotlin.native.runtime.SweepStatistics misses the word "number"

Native. Swift Export

New Features

• KT-82598 Swift Export: Custom name translation
• KT-66821 Swift Export: value class
• KT-84263 [Swift Export] Context Parameters on Functional Types
• KT-69431 Swift export: inline functions

Fixes

• KT-81593 Swift Export: suspend function returning Unit leads to incompilable code
• KT-84359 [Swift Export] nested functional type with Unit parameter
• KT-84358 [Swift Export] functional type with Unit parameter
• KT-84356 [Swift Export] functional type with single Unit parameter
• KT-83567 Swift Export: "IllegalStateException: Internal compiler error: doesn't correspond to any C type: kotlin.Unit": invalid closure is generated for suspend function which returns Unit
• KT-83397 [Swift Export] Functional return type with Unit parameter is emitted as invalid void parameter list ('void' must be the first and only parameter)
• KT-83743 Swift export: type arguments expected for generic typealias
• KT-84243 [Swift Export] Returning value of suspending functional type from suspending function yields invalid code
• KT-82568 Swift Export: Context Parameters
• KT-83398 [Swift export] converting non-escaping parameter to generic parameter may allow it to escape
• KT-83389 Swift Export: "ClassCastException" caused by suspend fun throwing Error
• KT-83116 Swift export generates bridges incompatible with language version 2.4
• KT-83749 [Swift Export] varargs and List uses the same mangling on bridges
• KT-83712 Swift Export ignores internal setter and generates invalid bridge code

Tools. BCV

• KT-78341 Outer scope's visibility is not considered when dumping const vals [ABI Validation JVM]
• KT-78305 Private constructor is written in ABI dump
• KT-82724 BCV incorrectly reports generated @JvmOverloads declarations as public
• KT-78367 Internal constructor infiltrated into a dump
• KT-78366 Protected method of enum should not be included into a dump

Tools. Build Tools API

New Features

• KT-80963 BTA: Add structured information about reported messages to KotlinLogger
• KT-84453 SSoT: provide a unified way to convert Enums to Strings

Fixes

• KT-82335 Promote the deprecation level for BTA prototype to the ERROR level
• KT-84015 Introduce detection of custom script names to new BTA API
• KT-83972 BTA: use isolated classloader for loading the BTA implementation in integration tests
• KT-84906 Make enum-based common arguments type-safe
• KT-75837 IC: Shrunk classpath snapshot name is hardcoded
• KT-84867 Make Xphases-to-* arguments type-safe
• KT-84850 Make kotlin-home type safe
• KT-84825 Make script-templates type safe
• KT-84546 Replace raw string path arguments with type-safe PathListType
• KT-84705 Make Xjdk-release to type-safe
• KT-84181 More verbose warning when CRI is enabled without using BTA
• KT-84436 Сompiler warnings are missing under Gradle -q option with -Werror
• KT-84324 Make X_ADD_MODULES BTA compiler argument type safe
• KT-84338 Make enum BTA JVM compiler argument type safe
• KT-84325 Make JVM_DEFAULT BTA compiler argument type safe
• KT-84449 Platform-Specific File.pathSeparator Hardcoded During SSOT Generation
• KT-84523 Add more forward compatibility tests
• KT-84249 Fix hardcoded path separator in -Xprofile argument to support absolute paths on Windows
• KT-84187 [BTA] Add more build operation immutability tests
• KT-84219 [BTA] Add additional tests on basic metrics collection
• KT-83781 Add additional tests for KT-79975 (BTA ability to cancel build operations)

Tools. CLI

• KT-84188 Create CLI argument for explicit context parameters
• KT-84609 Remove Nullability from Array-based CLI Compiler Arguments
• KT-84220 Enable Context Parameters by default in LV 2.4
• KT-84132 CLI: regression in deduplication of same-value arguments
• KT-83261 No error if pass an arbitrary string to a CLI argument that changes language features
• KT-83172 Boolean CLI argument for a language feature with explicit false value is allowed but has no effect
• KT-83341 Don't use the extension point registration mechanism from Intellij for K2 extensions

Tools. CLI. Native

• KT-82482 Compiler plugins are not propagated to frontend environment in ONE_STAGE_MULTI_MODULE Native mode

Tools. Compiler Plugins

• KT-66807 PowerAssert: Improve output diagram formatting
• KT-75266 PowerAssert: arrayOf() isn't displayed on the diagram
• KT-66808 PowerAssert: Add support for third-party assertion libraries
• KT-67332 "IndexOutOfBoundsException: Cannot pop operand off an empty stack." caused by function reference
• KT-83931 Power Assert: Compilation fails when using the metro plugin
• KT-83330 Lombok. An add methods with @Singular annotation in Java record doesn't work from kotlin
• KT-83204 Lombok. If @Data and @NoArgsConstructor are used together, then the constructor from @Data shouldn't be available
• KT-83336 Lombok. IllegalAccessError for constructor if @Value and @Builder are applied and used from another package
• KT-83352 Lombok. FileAnalysisException when @SuperBuilder is used with @Builder
• KT-83325 Lombok. Constructor with parameters is unavailable for a class with @Builder

Tools. Gradle

Fixes

• KT-74451 Deprecate access to Kotlin source sets in Android extension
• KT-82847 Raise deprecation to error for LanguageSettings.enableLanguageFeature DSL
• KT-84053 Deprecate support for Gradle 7.6-8.13 versions
• KT-78659 Remove 'kotlin-android-extensions' plugin id
• KT-79924 Make enableKotlinToolingMetadataArtifact deprecated
• KT-82933 Add a tab with results in TC
• KT-83130 [ToolingDiagnostic] incorrect problem ID formatting for acronyms and undefined locations in Gradle8 problems reports
• KT-84144 Bump the minimal supported AGP version to 8.5.2
• KT-84143 Reduce usage of Project in Tooling Diagnostics
• KT-83126 Remove out-of-process compilation mode
• KT-80466 Gradle: remove getPluginArtifactForNative()
• KT-81834 Compile against AGP 8.13 API
• KT-82960 Remove deprecated enableKotlinToolingMetadataArtifact in 2.4.0
• KT-75004 KGP: improve messaging when multiplatform tasks are disabled on incompatible OSes
• KT-77498 Test .swiftmodules more accurate in SwiftExportIT
• KT-84377 Broken package-list file on KGP/CMPG documentation page
• KT-84141 Add convenient host check
• KT-83592 Enable AFU in FusStatisticsIT.testKotlinxPlugins test after next AFU release
• KT-83775 Migrate KGP functionalTest to junit5

Tools. Gradle. BCV

• KT-83486 Create tasks only if abiValidation block called explicitly [ABI Validation]
• KT-84365 Gradle plugin of abi-validation should precisely define output files
• KT-80685 Simplify Gradle DSL [ABI Validation]
• KT-82410 Remove word legacy from DSL [ABI Validation]
• KT-83898 Classes produced by JvmMultifileClass ignore filters

Tools. Gradle. Dokka

• KT-82984 Support AGP9 in Dokka Gradle Plugin

Tools. Gradle. JS

• KT-81036 K/JS, Wasm: Remove deprecated ExperimentalDceDsl
• KT-64275 Gradle: remove deprecated symbols related to the legacy JS target
• KT-81040 Gradle: Remove deprecated Kotlin/JS tasks constructors

Tools. Gradle. Multiplatform

• KT-82265 Remove Android source set layout v1
• KT-82230 Cleanup 'org.jetbrains.gradle.apple.applePlugin' plugin usage
• KT-81958 Redundant “android target already exists” error when migrating to com.android.kotlin.multiplatform.library with androidTarget {}

Tools. Gradle. Native

• KT-84558 Upstream SwiftPM import work
• KT-84656 Concurrent issue in downloadKotlinNativeDistribution
• KT-84508 Add a warning on usage macos_x64 as host
• KT-84692 Misleading error message for disableNativeCache DSL without required Opt-In
• KT-83680 Remove trailing commas from the package manifest to be compatible with pre-16.3 Xcode

Tools. Gradle. Wasm

• KT-83566 K/Wasm: Support Wasm per module/klib compilation in Gradle plugin
• KT-84137 K/Wasm: Support binaryen run with multiple files
• KT-84230 Wasm: Fix test WasmYarnGradlePluginIT.testWasmUsePredefinedTooling

Tools. Kapt

• KT-84094 Kotlin daemon holds file locks for too long
• KT-80569 K2 KAPT: Class Literals Missing in Explicit Annotation Value Parameters
• KT-18791 Kapt: Constants from R class should not be inlined

Tools. Maven

• KT-84793 Use kotlin bootstrap to build kotlin-maven-plugin
• KT-83110 Remove dependency to intellij platform from kotlin-maven-plugin-test
• KT-83113 Configure kotlin.git/.idea to work nicely with maven-kotlin-plugin-test tests
• KT-83114 Migrate kotlin-maven-plugin-test from maven.invoker to junit6 + maven-verifier

Tools. Performance benchmarks

• KT-82928 Support local run for new benchmarks infra
• KT-84283 Add scenario generator for performance tests
• KT-83257 Parse gradle profile report

Tools. REPL

• KT-84160 [REPL] Resolve eval function during implicit body
• KT-74683 [K2 Repl] Does not support suspend functions
• KT-83689 [K2 REPL] Create raw FIR tests for repl snippets
• KT-82554 [REPL] Fix unresolved reference when using dataframe compiler-plugin
• KT-82578 [K2 REPL] Split snippet property declaration and initialization
• KT-82503 [K2 Repl] Nested class annotations are not available in the next snippet

Tools. Wasm

• KT-84396 [Wasm] Support multimodule in incremental compilation

Changelog

Backend. Wasm

• KT-84610 [Wasm] Failed to compile klibs in IC mode

Compiler

• KT-84566 Prevent launching Default dispatcher threads from IJ SDK in kotlin compiler
• KT-85358 Native: roll back the workaround for KT-84678 once MapLibre has been properly fixed
• KT-85626 @JvmRecord in commonMain breaks compileCommonMainKotlinMetadata with "Cannot access 'java.lang.Record'"
• KT-85405 Postpone/Revert DontIgnoreUpperBoundViolatedOnImplicitArguments
• KT-84678 K/N: Undefined symbol from SPM-added ObjC frameworks when linking iOS target
• KT-85021 False positive SUBCLASS_CANT_CALL_COMPANION_PROTECTED_NON_STATIC error in multi-module project

JavaScript

• KT-82395 Support top-level declarations from compiler plugins in JS incremental compilation
• KT-84475 K/JS: false-positive exportability warnings in multi-module project
• KT-84633 Kotlin/JS: "Serializer for class not found" error when IR output granularity is whole-program
• KT-85047 Kotlin/JS: @JsStatic on suspend fun of class companion generates incorrect d.ts
• KT-84517 K/JS: bad mappings data in outputted Kotlin stdlib source map

Libraries

• KT-71848 Kotlinx.metadata: Add CompilerPluginData into Km API

Native. C and ObjC Import

• KT-85399 Kotlin/Native: TypeCastException when casting ObjC Protocol MetaClass with genericSafeCasts enabled
• KT-85508 K/N: TypeCastException when using nw_parameters_create_secure_tcp block parameter on 2.3.20

Tools. Gradle

• KT-84729 Update Gradle plugin-publish version to enable configuration cache badge on Gradle plugins portal

Tools. Gradle. Compiler plugins

• KT-85257 AGP/Compose: MergeMappingFileTask clears R8 artifacts due to @OutputDirectory annotation on AGP 9.1+

Tools. Scripts

• KT-85105 Scripts: JVM backend internal error (IR lowering) when scratch file contains anonymous object
• KT-85103 Exception while generating code when explain destructuring decls
• KT-84842 scriptCompilationClasspathFromContext behavior changed from 2.3.10 to 2.3.20
• KT-85029 Kotlin Scripting: ScriptDiagnostic reports "at null" instead of error location

Tools. Statistics (FUS)

• KT-85628 KGP: composite build FUS metrics fail on access of 'configurationTimeMetrics'

Changelog

Compiler

• KT-85626 @JvmRecord in commonMain breaks compileCommonMainKotlinMetadata with "Cannot access 'java.lang.Record'"

Native. C and ObjC Import

• KT-85508 K/N: TypeCastException when using nw_parameters_create_secure_tcp block parameter on 2.3.20

Tools. Scripts

• KT-85105 Scripts: JVM backend internal error (IR lowering) when scratch file contains anonymous object
• KT-85103 Exception while generating code when explain destructuring decls

Tools. Statistics (FUS)

• KT-85628 KGP: composite build FUS metrics fail on access of 'configurationTimeMetrics'

Changelog

Backend. Wasm

• KT-84610 [Wasm] Failed to compile klibs in IC mode

Compiler

• KT-84678 K/N: Undefined symbol from SPM-added ObjC frameworks when linking iOS target
• KT-84566 Prevent launching Default dispatcher threads from IJ SDK in kotlin compiler
• KT-85021 False positive SUBCLASS_CANT_CALL_COMPANION_PROTECTED_NON_STATIC error in multi-module project

JavaScript

• KT-82395 Support top-level declarations from compiler plugins in JS incremental compilation
• KT-84633 Kotlin/JS: "Serializer for class not found" error when IR output granularity is whole-program
• KT-85047 Kotlin/JS: @JsStatic on suspend fun of class companion generates incorrect d.ts
• KT-84517 K/JS: bad mappings data in outputted Kotlin stdlib source map

Libraries

• KT-71848 Kotlinx.metadata: Add CompilerPluginData into Km API

Tools. Gradle

• KT-84729 Update Gradle plugin-publish version to enable configuration cache badge on Gradle plugins portal

Tools. Gradle. Compiler plugins

• KT-85257 AGP/Compose: MergeMappingFileTask clears R8 artifacts due to @OutputDirectory annotation on AGP 9.1+

Tools. Scripts

• KT-84842 scriptCompilationClasspathFromContext behavior changed from 2.3.10 to 2.3.20
• KT-85029 Kotlin Scripting: ScriptDiagnostic reports "at null" instead of error location

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 @BuilderInference
• KT-80786 Annotate kotlin-stdlib-jdk7/8 with @IgnorableReturnValue
• KT-83181 Remove @IgnorableReturnValue from contract DSL functions
• KT-82033 Array<Array<T>>.flatten fails with obscure error when total length exceeds List's size limit
• KT-83290 Remove unnecessary ExperimentalTime annotation from Uuid functions
• KT-83026 Specify compareTo behavior for Boolean
• KT-82868 Restore accidentally deleted JS-specific note in ArrayList documentation
• KT-81563 Document kotlin.collections.HashMap and HashSet
• KT-81562 Document kotlin.collections.ArrayList
• KT-60535 Mark SubclassOptInRequired and RequiresOptIn with MustBeDocumented
• KT-64649 Add explanation to "A compileOnly dependency is used in the Kotlin/Native target" warning message

Native

• KT-83542 Switch the default GC back to PMCS in 2.3.20-RC
• KT-82387 Kotlin <-> Xcode compatibility issue
• KT-75806 KN Compiler with debug build can not produce executable with debug info
• KT-81828 Update exception messages regarding disabling native cache
• KT-81495 Consider making Kotlin/Native distribution compiler cache reproducible
• KT-81501 Make Kotlin/Native distribution runtime .bc and fingerprint reproducible
• KT-80790 'Argument list too long' error when using dynamic_caches
• KT-48566 ExceptionInInitializerError when configuring Gradle project with kotlin-multiplatform plugin on a host unsupported by Kotlin/Native

Native. Build Infrastructure

• KT-82886 KonanTarget's clinit causes deadlock
• KT-81345 Temporary turned off Swift Export execution tests
• KT-80869 Extract per-module test generators for Native tests
• KT-82028 Kotlin/Native: move runtime building flags to runtime building code
• KT-81500 Make Kotlin/Native distribution shared libraries reproducible
• KT-72011 Kotlin/Native: consider building platform libraries with bootstrap compiler
• KT-81666 Kotlin/Native: build stdlib with the bootstrap compiler

Native. C and ObjC Import

• KT-79741 Native: implement type checking against Objective-C protocols without protocolGetter
• KT-83039 Native: mark header-defined functions and globals unavailable with -Xccall-mode direct
• KT-82200 Native: implement type checking against Objective-C protocols with objc_runtime_name without protocolGetter
• KT-82669 Kotlin/Native: cinterop tests failure with no class for metaclass
• KT-79742 Native: import C global variables without C wrappers
• KT-81937 Native: switch cinterop to -Xccall-mode both by default for custom cinterop klibs
• KT-81548 Native: compiler doesn't sanitize CCall.Direct symbol names in C stubs
• KT-81538 Native: InteropBridgesNameInventor doesn't handle legitimate '$' characters in function names
• KT-81017 Native: compiler can't call CCall.Direct with '$' in the symbol name

Native. ObjC Export

• KT-82160 K/N: bridge for fake override is not built but requested
• KT-83736 Objective-C export with objcExportBlockExplicitParameterNames generates invalid block signature when lambda parameter is named id
• KT-83014 Native: experimental support for generating an NS_ENUM in addition to an Objective-C class for Kotlin classes
• KT-76637 ObjCExport: K1 + K2 integration test

Native. Runtime

• KT-82077 Kotlin/Native: in runtime make main module depend on mm module

Native. Runtime. Memory

• KT-82635 Enable CMS GC by default in 2.3.20-Beta1
• KT-83470 Potential race condition in TryRequestThreadsSuspension due to initialization order
• KT-83549 Provide an experimental Platform property which returns information about object allocation mode
• KT-83535 Typo in out-of-memory error message
• KT-81152 Kotlin/Native: deprecate isMemoryLeakCheckerActive
• KT-81156 Kotlin/Native: deprecate forceCheckedShutdown

Native. Swift Export

New Features

• KT-82908 Swift Export: bridges for FT should be recursive

Fixes

• KT-82054 Swift Export: private set is ignored by swift export
• KT-83499 Swift Export: trampoulines w/ varargs results in a broken swift code
• KT-83655 Typealias to a closure receiving a closure results in broken swift code
• KT-82053 Swift Export: Returning generic on top level function produces uncompilable code
• KT-80971 Swift Export: Support exception throwing
• KT-83141 Swift Export: suspendable covariant functional type
• KT-82907 Swift Export: attributes are not printed for parameters of closures
• KT-80970 Swift Export: Support cancellation
• KT-82726 Swift Export: filters out wrong module for coroutines
• KT-81591 Custom type translation rules in Swift export
• KT-81270 K/N - Build fails when exposing suspend functions

Tools. BCV

• KT-80938 Binary compatibility validation: can't exclude container types of Repeatable annotations by filters.excluded.byNames
• KT-83484 Create fat-jar artifact for abi-tools [ABI Validation]
• KT-80747 Refactor API of ABI tools [ABI Tools]

Tools. Build Tools API

New Features

• KT-80681 BTA: introduce a special argument for passing compiler plugins
• KT-80338 Kotlin CRI generation
• KT-78198 BTA: implement basic metrics collection
• KT-79975 BTA: add ability to cancel build operations
• KT-81790 [BTA] Make build operations and configuration immutable after execute
• KT-82702 BTA: Allow collecting compiler lookups in non-incremental mode
• KT-81847 Add CRI <-> BTA integration
• KT-81845 Add CRI <-> Maven integration

Fixes

• KT-84577 BTA: API 2.3.20 incompatible with compiler 2.3.10
• KT-82682 BTA: reading non-nullable arguments may return null or throw NPE
• KT-81729 BTA: loading from a classloader without implementation fails with CNFE instead of error with explanation
• KT-83971 BTA: OperationCancelledException cannot be thrown properly from isolated classloader
• KT-82167 Add BuildTimeMetric for the CRI data generation
• KT-81846 Add FUS for CRI usage in Gradle / Maven
• KT-82399 [BTA] JvmClasspathSnapshottingOperationImpl doesn't use Option defaults
• KT-82039 BuildEvent compilation error missing with KGP 2.3.0-Beta1
• KT-81887 Implement the CRI lookup data generation
• KT-81886 Implement the CRI data serialization
• KT-81780 Add Gradle <-> CRI integration tests
• KT-81645 BTA prints unreadable version in "option available only since" error (shows KotlinReleaseVersion@hash instead of 2.x.y)

Tools. CLI

• KT-83044 Report redundant CLI arguments when they have no effect
• KT-83202 Report all errors during parsing CLI arguments instead of a single one
• KT-73320 Migrate the main JS CLI pipeline to the phased structure
• KT-81898 Introduce a CLI option to disable source file sorting
• KT-73606 Provide a unified interface for managing the reporting of compiler warnings
• KT-48419 Using a @RequiresOptIn API that does not exist should have an option to not output a warning
• KT-81861 Introduce a mechanism that allows suppressing CLI diagnostics
• KT-82321 KMP Separate Compilation: Common fragments are missing forward declaration symbol providers
• KT-81551 Introduce an experimental CLI option for enabling local type aliases
• KT-74196 Remove patched copy of com.intellij.util.lang.JavaVersion from the Kotlin repo

Tools. CLI. Native

• KT-64509 Refactor Kotlin/Native compiler setup: run FE without KonanConfig

Tools. Compiler Plugin API

• KT-83823 Deprecate PreprocessedVirtualFileFactoryExtension
• KT-82809 [FIR][IC] New containingFileName parameter API is not actually compatible with IC
• KT-46709 IR plugin lookups don't work as expected for expect class with actual typealias
• KT-82518 Disable automatic body generation of the plugin-generated callables
• KT-82159 [FIR] Automatically add expressions to properties or functions
• KT-58886 K2: compiler plugin generated top level declarations cause AssertionError on K/JS and K/Native

Tools. Compiler Plugins

New Features

• KT-71893 Support @Builder lombok annotation on methods
• KT-28594 Add a 'jpa' pre-defined flavor to the allOpen compiler plugin.
• KT-81604 Lombok Kotlin compiler plugin and -Werror: Unable to ignore warning for the plugin appliance

Fixes

• KT-83119 Lombok. canEqual is not available from kotlin for a class with @Data annotation
• KT-83334 Lombok. Builder function is unavailable for a generic class
• KT-83063 Lombok: Setter/getter is not available with a protected access level
• KT-83217 Lombok. With method is available for the static field
• KT-83120 Lombok. A constructor is available for a class with an existing constructor and @Data/@Value annotation
• KT-83256 Lombok. Setter is available for non-final fields if @Value and @Data/@Setter are used together
• KT-83251 Lombok. Constructor from @Value includes fields that are initialized in declaration
• KT-83252 Lombok. Class marked with @Value isn't final
• KT-83085 Lombok: getter/setter is available for a static field if class is annotated
• KT-83078 Lombok: getter and setter are not available for a static Java field
• KT-82341 Migrate official compiler plugins to IC-safe reference... API

Tools. Compiler plugins. Compose

• KT-84218 [2.3.20-Beta1] "IllegalStateException: no implementation for FUN MISSING_DECLARATION" during bitcode lowering
• KT-84055 Reference to lambda in lambda in function 'TextField' can not be evaluated

Tools. Compiler plugins. Serialization

• KT-82351 Migrate kotlinx.serialization to IC-safe reference... API
• KT-76949 Serialization: "IllegalStateException: Serializer for element of type kotlin.Any has not been found" on custom serializer for Map<String, Any?>
• KT-73107 Serialization: "IllegalStateException: Serializer for element of type kotlin.Any? has not been found" with star projection

Tools. Gradle

New Features

• KT-79389 Add allopen plugin + JPA preset to kotlin.plugin.jpa
• KT-78200 Gradle: enable JVM compilation through BTA by default
• KT-81844 Add CRI <-> Gradle integration

Performance Improvements

• KT-84152 Memory Leak and OOM Errors in Kotlin Gradle Plugin 2.3.20-Beta2 with in-process execution mode

Fixes

• KT-80186 Remove usage of deprecated Gradle API Project.container(...)
• KT-78754 KGP: Remove usages of isVisible/setVisible
• KT-80356 Compatibility with Gradle 9.2.0 release
• KT-78763 Compatibility with Gradle 9.1.0 release
• KT-83316 [BTA] Build Reports missing information when JVM compilation uses Build Tools API
• KT-82885 Run tests against Gradle 9.3.0
• KT-83125 Deprecate out-of-process compilation mode
• KT-82323 Deprecate LanguageSettings.enableLanguageFeature DSL
• KT-83323 Run integration tests against Gradle 9.2
• KT-82884 Compile against Gradle API 9.3.0
• KT-78104 Deprecate CleanableStore infrastructure
• KT-80096 Strange "Inconsistent JVM Target Compatibility" warning
• KT-82715 Declaring dependencies using multi-string notation has been deprecated
• KT-83161 CRI: it is not clear that CRI generation requires BTA being enabled
• KT-82717 Specifying 'org.gradle.java.installations.auto-detect' as a project property on the command line has been deprecated
• KT-81830 Create autogenerated kotlin version constants to be used with disableNativeCache DSL
• KT-83322 Compile against Gradle 9.2 API
• KT-81831 Verify Problems API implementation with Gradle guidelines
• KT-80120 Support colored value for --console command in Gradle 9.1
• KT-81400 ToolingDiagnosticFactory: check if documentationLink set multiple times
• KT-83070 The KGP api reference is missing a description
• KT-82459 Improve iOS simulator boot implementation
• KT-80008 Track cross compilation status from project dependencies
• KT-78764 Compile against Gradle 9.1 API

Tools. Gradle. BCV

• KT-80674 Rename tasks to avoid using legacy word [ABI Validation]
• KT-80614 Add dependency on abi check from gradle's check task [ABI Validation]
• KT-80827 Delete DSL for working with dump variants [ABI Validation]
• KT-80823 Stabilize DSL for filtering [ABI Validation]

Tools. Gradle. Cocoapods

• KT-80641 EXECUTABLE_DEBUG_DYLIB_PATH problem
• KT-80644 Cocoapod plugin builds a synthetic project for "generic/platform=iOS Simulator"

Tools. Gradle. JS

• KT-84772 Bundled yarn.lock for kotlinWasmToolingSetup does not include @swc/helpers@0.5.17
• KT-82946 Js, Wasm: Upgrade NPM dependencies

Tools. Gradle. Multiplatform

New Features

• KT-77258 Query status of cross-compilation or compilation task
• KT-81849 Replace kotlin-test-common and kotlin-test-annotations-common with just kotlin-test

Fixes

• KT-83917 compileCommonMainKotlinMetadata fails in CMP core repository with Kotlin 2.3.20-Beta1
• KT-82090 Kotlin JVM + Android Shared Source set fails Import with the Project Isolation enabled
• KT-81973 NPE with Cannot invoke "java.util.List.get(int)" because "path" is null in KMP + Android project
• KT-79257 Consider deprecating and removing kotlin.kmp.isolated-projects.support
• KT-81944 Legacy KMP Android uses wrong configurations to infer common dependencies
• KT-83687 Revert deprecation of 'androidTarget' for AGP lower than 9
• KT-81536 "Couldn't resolve dependency in 'commonMain' for all target platforms" in 2.2.20-Beta2
• KT-81724 IntelliJ successfully resolves imports that are not actually available in the given module
• KT-79073 compileTest* tasks pass separateCompilation parameters but don't behave accordingly
• KT-71130 Enable Isolated Projects support by default for KMP

Tools. Gradle. Native

• KT-84759 iosX64 should not be marked as deprecated in Kotlin Gradle DSL
• KT-83598 KotlinNativeDownloadTask build caching is unsafe
• KT-80715 Deprecate kotlin.native.cacheKind and introduce DSL instead
• KT-83353 DisableNativeCache breaks up-to-date checks for non-cacheable K/N targets
• KT-81443 ConfigurationCacheError on Linux arm64 due to disabled iOS targets
• KT-82970 Warning about disabled K/N caches for non-cacheable targets is printed twice
• KT-82786 Warning about disabled K/N caches is displayed twice

Tools. Gradle. Swift Export

• KT-82727 Swift Export: generated kotlin bridges don't see neighboring modules

Tools. Gradle. Wasm

• KT-82525 K/Wasm: kotlinToolingSetup does not depend on package manager installation

Tools. Incremental Compile

• KT-80483 Incorporate IC lookups into reference... methods of IrPluginContext

Tools. JPS

• KT-76927 Sw

Note truncated.