Changelog

Backend. Wasm

• KT-66515 Wasm: "call param types must match" during the build
• KT-67435 K/Wasm: import.meta.url transforming into absolute local path in webpack
• KT-66905 K/Wasm: support new version of exception handling proposal

Compiler

New Features

• KT-59688 K2: consider removing smartcasts only from the only visibile property with specific name, not from all of them

Performance Improvements

• KT-67388 FP intellij: performance degradation in build 611
• KT-67507 K2: Slow compilation times when a class has a lot of possibly conflicting declarations

Fixes

• KT-57678 K2: Inconsistency in how K2 analyzes unresolved code for loops and changing closures
• KT-66976 Some value class diagnostics are missed
• KT-54920 K2: when with a single branch stops being exhaustive the second time it's done
• KT-67307 K2: "Cannot find cached type parameter by FIR symbol" in JpaRepository.saveAll
• KT-65771 K2: "IndexOutOfBoundsException: Cannot pop operand off an empty stack" when calling method imported using typealias as callable qualifier
• KT-67502 K2: "property must be initialized or be abstract" with try-finally in secondary constructor
• KT-67456 K2: "property must be initialized or be abstract" depending on constructor declaration order
• KT-67628 K2: "IllegalArgumentException: Expected nullable type" — alias of nullable type analyzed as non-nullable in type parameter
• KT-67625 K2: Array aliases can't be used as vararg values
• KT-67624 K2: False negative "The feature "break continue in inline lambdas" is experimental and should be enabled explicitly" in elvis operator
• KT-60271 K2: origins are not set on compare operators
• KT-44557 Implement main function detection to FIR
• KT-67593 K2: false negative SUPER_CALL_WITH_DEFAULT_PARAMETERS
• KT-67484 K2: FIR2IR generates incorrect access to f/o of lateinit internal var
• KT-67486 K2: Calling method from a Java (implementing a Kotlin class) with named parameters is no longer possible if Java method has different parameter names
• KT-47382 JVM / IR: "AssertionError: Unbound private symbol IrFieldSymbolImpl" caused by string template in constructor and extension property
• KT-67581 K2: Compiler fails on actualizing abstract class with sealed Java class via type alias
• KT-67014 K1/K2 handle when expression as annotation target differently
• KT-67254 K1/K2 both allow annotations on loops, assignments, array sets
• KT-67224 K2/Native: Member overrides different '[@Throws](https://github.com/Throws)' filter from separate module
• KT-66960 K2. KMP. False negative 'when' expression must be exhaustive without sealed class inheritor from common source-set
• KT-63466 [@NonNull](https://github.com/NonNull) on a type-variable usage doesn't take precedence over a wildcard type argument
• KT-56134 K2: NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER diagnostic is reported for the wrong symbol
• KT-59872 K2: Disappeared TYPE_MISMATCH
• KT-67192 K2: Disappeared TYPE_MISMATCH [3]
• KT-67191 K2: Disappeared TYPE_MISMATCH [4]
• KT-64860 K2: Consider using different ConstraintPosition when fixing variables for PCLA
• KT-67189 K2: Disappeared TYPE_MISMATCH [5]
• KT-67551 K2: No wrong annotation target error for for statement
• KT-67367 K2: Incorrect resolution to top-level function with less specific signature in presence of SAM constructor on the same tower level
• KT-67374 K2: Object is not smartcasted to type parameter type
• KT-67264 K2: "argument type mismatch" with suspend lambda and java wildcard
• KT-67221 K2: "new inference error [NewConstraintError at Incorporate TypeVariable" for captured type
• KT-67311 K2: "Argument type mismatch" caused by lambda type when using named arguments
• KT-62043 K2: Fix FirCompileKotlinAgainstCustomBinariesTest.testRawTypes
• KT-66743 Lambda receivers and anonymous function parameters of inaccessible types are allowed
• KT-67315 K2: Some default imports are not excluded
• KT-56126 Avoid using descriptors at JvmPlatformAnalyzerServices::computePlatformSpecificDefaultImports
• KT-66513 K2: Suppressing OPT_IN_USAGE_ERROR is now a warning in K2, preventing safe code gen compatible with -Werror
• KT-67314 PCLA works inconsistently with smart-cast related CS forks
• KT-67144 K2: potential NPE when assigning to unstable vars
• KT-66971 K2: missing SMARTCAST_IMPOSSIBLE on open val declared in another module
• KT-66904 K2: possible NPE when reassigning captured variables
• KT-67212 K2: "Failed to find functional supertype for class org.jetbrains.kotlin.fir.types.ConeCapturedType"
• KT-67283 K2: No SAM conversion for fun interface with abstract toString
• KT-66768 K1: False positive UNRESOLVED_REFERENCE in super.getFirst/getLast call
• KT-67318 Compiler fails with OutOfMemoryError on combination of PCLA+smart cast
• KT-65812 K2: "OutOfMemoryError: Java heap space" in kotlin.utils.SmartList.add
• KT-66956 K2: false negative CONST_VAL_WITH_NON_CONST_INITIALIZER for inc/dec operators
• KT-67205 K2: can't deserialize annotation with local class as argument
• KT-65449 K2: build KAPT user project and pass it to CI
• KT-67142 K2: IrFakeOverrideBuilder: AbstractMethodError on raw type argument in a Java superclass
• KT-62570 IncompatibleClassChangeError due to overriding final method
• KT-67190 K2: Disappeared TYPE_MISMATCH [2]
• KT-67188 K2: Disappeared TYPE_MISMATCH [6]
• KT-67187 K2: Disappeared TYPE_MISMATCH [1]
• KT-63381 IrFakeOverrideBuilder: PublishedApi affects overridability of internal members
• KT-59856 K2: Check ConeDiagnostics that are not mapped to KtDiagnostics
• KT-57502 K2: Smart casts should be forbidden if variable that remembers the smart cast is declared by delegation
• KT-63967 K2: Missing getterSignature in metadata for script variables
• KT-59372 K2: Missing SELF_CALL_IN_NESTED_OBJECT_CONSTRUCTOR_ERROR
• KT-60526 K2: Fix the TODO in convertToIr.kt
• KT-67027 K2: Review all use-sites of annotation arguments utilities
• KT-66953 K2: toByte() call on Char leads to ClassCastException for klib backends
• KT-65415 K2: Stdlib K2 build error: IrConstructorSymbolImpl is already bound

IR. Actualizer

• KT-67488 K2: AssertionError No such value argument slot in IrConstructorCallImpl: 0 (total=0

JavaScript

• KT-66922 K2 JS: Intrinsic Float/Double toString producing wrong numbers
• KT-63038 Compilation of suspend functions into ES2015 generators
• KT-8373 JS: support ES6 as compilation target
• KT-64951 Kotlin-Multiplatform does not allow JSExport of expect

Klibs

• KT-67401 KLib ABI dump: write plain targets in the manifest

Native. Testing

• KT-67501 Mute flaky driver tests on macOS agents

Tools. CLI

• KT-67417 CLI: Remove option -Xrepeat
• KT-65451 K2: CLI: false positive warning "scripts are not yet supported with K2 in LightTree mode" on irrelevant files in source directory

Tools. Compiler Plugins

• KT-67489 JsPlainObjects Plugin: Method not found when consuming
• KT-67523 [K2] Actualizer cannot reconcile mismatched parameter names from java supertypes
• KT-67354 K2 Parcelize: support efficient Parcel serializer for parcelables in the same module
• KT-64454 K2: Implement ParcelizeIrBytecodeListingTestGenerated for K2
• KT-67353 K2 Parcelize: support parcelableCreator intrinsic

Tools. Gradle

New Features

• KT-67253 Support per-target configuration in compose-compiler-gradle-plugin

Fixes

• KT-64115 KGP + JVM/JS/WASM: The same library can be passed twice to the compiler
• KT-64567 [FUS] Add boolean flag into kotlin.gradle.performance collector
• KT-67685 KotlinBaseApiPlugin regression with Gradle's Configuration Cache in 2.0.0-RC1
• KT-67515 Remove 'experimental' from compose strong skipping mode
• KT-67441 Gradle remote cache misses in the compose plugin
• KT-67602 Compose gradle plugin: a deprecated plugin option 'experimentalStrongSkipping' is added by default that causes a warning
• KT-67200 Compose gradle plugin: 'suppressKotlinVersionCompatibilityCheck' option is duplicated if added as a kotlin option for the KotlinCompile task and kapt is used
• KT-67216 Compose compiler plugin: false-positive versions incompatibility is reported
• KT-66459 PowerAssert: Improve design of excludedSourceSets extension property
• KT-61913 Validate LanguageSettings KDoc

Tools. Gradle. Multiplatform

• KT-57141 K2: KotlinCompile task input named 'multiplatformStructure.fragments.$0.sources' is tracked in a pure JVM kotlin project together with changes of sources
• KT-65480 MissingNativeStdlibChecker checks existence of konanDistribution.stdlib during configuration phase
• KT-67127 KMP: IDE Dependency Resolver for CInterops reports errors on linux and windows machines
• KT-63536 KMP: MetadataDependencyTransformationTask is not Thread Safe

Tools. Gradle. Native

• KT-67522 K/N toolchain: unclear compilation error if path specified as a value for the kotlin.native.home doesn't provide the kotlin native compiler downloaded
• KT-67521 K/N warning checking existence of the standard library isn't displayed when the native toolchain enabled and the kotlin native home dir doesn't contain stdlib

Tools. Kapt

• KT-66541 K2 KAPT: KotlinIllegalArgumentExceptionWithAttachments: Expected expression 'FirPropertyAccessExpressionImpl' to be resolved

Tools. Scripts

• KT-66395 K2: Scripting test testHelloSerialization fails on K2

Tools. Wasm

• KT-65864 K/Wasm: update Node.js to 22.x