fixup! step 2: keep iterators in public, but deprecated with error

Drop unsignedLiteralsOn1_2 because apiversion 1.2 is no longer supported
Drop experimental unsigned literals diagnostic test

.gitignore

@@ -32,6 +32,8 @@ build/
 .idea/modules
 .idea/runConfigurations/JPS_*.xml
 .idea/runConfigurations/PILL_*.xml
+.idea/runConfigurations/_FP_*.xml
+.idea/runConfigurations/_MT_*.xml
 .idea/libraries
 .idea/modules.xml
 .idea/gradle.xml

.idea/dictionaries/sebastiansellmair.xml

@@ -0,0 +1,8 @@
+<component name="ProjectDictionaryState">
+  <dictionary name="sebastiansellmair">
+    <words>
+      <w>cinterops</w>
+      <w>interops</w>
+    </words>
+  </dictionary>
+</component>

.idea/runConfigurations/Generate_Compiler_Tests.xml

@@ -1,5 +1,5 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="Generate Compiler Tests" type="GradleRunConfiguration" factoryName="Gradle" folderName="Generators">
+  <configuration default="false" name="Generate Compiler Tests" type="GradleRunConfiguration" factoryName="Gradle">
     <ExternalSystemSettings>
       <option name="executionName" />
       <option name="externalProjectPath" value="$PROJECT_DIR$/compiler" />

ReadMe.md

@@ -106,6 +106,8 @@ To reproduce TeamCity build use `-Pteamcity=true` flag. Local builds don't run p
 **OPTIONAL:** Some artifacts, mainly Maven plugin ones, are built separately with Maven.
 Refer to [libraries/ReadMe.md](libraries/ReadMe.md) for details.
 
+To build Kotlin/Native, see
+[kotlin-native/README.md](kotlin-native/README.md#building-from-source).
 
 ### Building for different versions of IntelliJ IDEA and Android Studio
 
@@ -145,28 +147,6 @@ From this root project there are Run/Debug Configurations for running `IDEA` or
 * Run the `IDEA` run configuration in the project
 * A child IntelliJ IDEA with the Kotlin plugin will then startup
 
-### Including into composite build
-
-To include kotlin compiler into [composite build](https://docs.gradle.org/current/userguide/composite_builds.html) you need to define `dependencySubstitution` for `kotlin-compiler` module in `settings.gradle.kts`
-
-```Kotlin
-includeBuild("/path/to/kotlin") {
-    dependencySubstitution {
-        substitute(module("org.jetbrains.kotlin:kotlin-compiler"))
-            .with(project(":include:kotlin-compiler"))
-    }
-}
-```
-
-or in `settings.gradle`
-
-```Groovy
-includeBuild('/path/to/kotlin') {
-    dependencySubstitution {
-        substitute module('org.jetbrains.kotlin:kotlin-compiler') with project(':include:kotlin-compiler')
-    }
-}
-```
 
 # License
 Kotlin is distributed under the terms of the Apache License (Version 2.0). See [license folder](license/README.md) for details.

build.gradle.kts

@@ -27,7 +27,7 @@ buildscript {
     dependencies {
         bootstrapCompilerClasspath(kotlin("compiler-embeddable", bootstrapKotlinVersion))
 
-        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.25")
+        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.26")
         classpath(kotlin("gradle-plugin", bootstrapKotlinVersion))
         classpath(kotlin("serialization", bootstrapKotlinVersion))
         classpath("org.jetbrains.dokka:dokka-gradle-plugin:0.9.17")
@@ -159,6 +159,7 @@ rootProject.apply {
     from(rootProject.file("gradle/checkArtifacts.gradle.kts"))
     from(rootProject.file("gradle/checkCacheability.gradle.kts"))
     from(rootProject.file("gradle/retryPublishing.gradle.kts"))
+    from(rootProject.file("gradle/modularizedTestConfigurations.gradle.kts"))
 }
 
 IdeVersionConfigurator.setCurrentIde(project)

buildSrc/build.gradle.kts

@@ -11,10 +11,8 @@ buildscript {
 
     repositories {
         if (cacheRedirectorEnabled) {
-            maven("https://cache-redirector.jetbrains.com/jcenter.bintray.com")
             maven("https://cache-redirector.jetbrains.com/maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
         } else {
-            jcenter()
             maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
         }
 
@@ -24,7 +22,7 @@ buildscript {
     }
 
     dependencies {
-        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.25")
+        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.26")
         classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:${project.bootstrapKotlinVersion}")
         classpath("org.jetbrains.kotlin:kotlin-sam-with-receiver:${project.bootstrapKotlinVersion}")
     }
@@ -84,10 +82,9 @@ extra["versions.androidDxSources"] = "5.0.0_r2"
 extra["customDepsOrg"] = "kotlin.build"
 
 repositories {
-    jcenter()
+    mavenCentral()
     maven("https://jetbrains.bintray.com/intellij-third-party-dependencies/")
     maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/kotlin-dependencies")
-    maven("https://kotlin.bintray.com/kotlinx")
     gradlePluginPortal()
 
     extra["bootstrapKotlinRepo"]?.let {
@@ -147,8 +144,8 @@ java {
 dependencies {
     implementation(kotlin("stdlib", embeddedKotlinVersion))
     implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:${project.bootstrapKotlinVersion}")
-    implementation("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.25")
-    implementation("com.gradle.publish:plugin-publish-plugin:0.12.0")
+    implementation("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.26")
+    implementation("com.gradle.publish:plugin-publish-plugin:0.13.0")
 
     implementation("net.rubygrapefruit:native-platform:${property("versions.native-platform")}")
     implementation("net.rubygrapefruit:native-platform-windows-amd64:${property("versions.native-platform")}")

buildSrc/settings.gradle

@@ -20,7 +20,7 @@ buildscript {
         }
     }
     dependencies {
-        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.25")
+        classpath("org.jetbrains.kotlin:kotlin-build-gradle-plugin:0.0.26")
     }
 }
 

buildSrc/src/main/kotlin/pill/PillExtension.kt

@@ -10,31 +10,16 @@ import java.io.File
 import org.gradle.api.Project
 
 open class PillExtension {
+    /*
+     * Here's how you can specify a custom variant:
+     * `./gradlew pill -Dpill.variant=<NAME>`
+     */
     enum class Variant {
-        // Default variant (./gradlew pill)
-        BASE() {
-            override val includes = setOf(BASE)
-        },
-
-        // Full variant (./gradlew pill -Dpill.variant=full)
-        FULL() {
-            override val includes = setOf(BASE, FULL)
-        },
-
-        // Do not import the project to JPS model, but set some options for it
-        NONE() {
-            override val includes = emptySet<Variant>()
-        },
-
-        // 'BASE' if the "jps-compatible" plugin is applied, 'NONE' otherwise
-        DEFAULT() {
-            override val includes = emptySet<Variant>()
-        };
-
-        abstract val includes: Set<Variant>
+        BASE, // Includes compiler and IDE (default)
+        FULL, // Includes compiler, IDE and Gradle plugin
     }
 
-    open var variant: Variant = Variant.DEFAULT
+    open var variant: Variant? = null
 
     open var excludedDirs: List<File> = emptyList()
 
@@ -45,7 +30,7 @@ open class PillExtension {
 
     @Suppress("unused")
     fun serialize() = mapOf<String, Any?>(
-        "variant" to variant.name,
+        "variant" to variant?.name,
         "excludedDirs" to excludedDirs
     )
 }

buildSrc/src/main/kotlin/tasks.kt

@@ -46,6 +46,7 @@ val kotlinGradlePluginAndItsRequired = arrayOf(
     ":kotlin-gradle-subplugin-example",
     ":kotlin-stdlib-common",
     ":kotlin-stdlib",
+    ":kotlin-stdlib-jdk7",
     ":kotlin-stdlib-jdk8",
     ":kotlin-stdlib-js",
     ":examples:annotation-processor-example",

compiler/backend/src/org/jetbrains/kotlin/codegen/ClassFileFactory.java

@@ -52,13 +52,14 @@ import org.jetbrains.org.objectweb.asm.Type;
 import java.io.File;
 import java.nio.charset.StandardCharsets;
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
 
 import static org.jetbrains.kotlin.codegen.JvmCodegenUtil.getMappingFileName;
 
 public class ClassFileFactory implements OutputFileCollection {
     private final GenerationState state;
     private final ClassBuilderFactory builderFactory;
-    private final Map<String, OutAndSourceFileList> generators = new LinkedHashMap<>();
+    private final Map<String, OutAndSourceFileList> generators = Collections.synchronizedMap(new LinkedHashMap<>());
 
     private boolean isDone = false;
 
@@ -346,7 +347,9 @@ public class ClassFileFactory implements OutputFileCollection {
 
         @Override
         public byte[] asBytes(ClassBuilderFactory factory) {
-            return factory.asBytes(classBuilder);
+            synchronized(this) {
+                return factory.asBytes(classBuilder);
+            }
         }
 
         @Override

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/GlobalInlineContext.kt

@@ -9,15 +9,16 @@ import com.intellij.psi.PsiElement
 import org.jetbrains.kotlin.descriptors.CallableDescriptor
 import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.utils.threadLocal
 import java.util.*
 
 class GlobalInlineContext(private val diagnostics: DiagnosticSink) {
     // Ordered set of declarations and inline calls being generated right now.
     // No call in it should point to a declaration that's before it in the stack.
-    private val inlineCallsAndDeclarations = LinkedList<Any? /* CallableDescriptor | PsiElement? */>()
-    private val inlineDeclarationSet = mutableSetOf<CallableDescriptor>()
+    private val inlineCallsAndDeclarations by threadLocal { LinkedList<Any? /* CallableDescriptor | PsiElement? */>() }
+    private val inlineDeclarationSet by threadLocal { mutableSetOf<CallableDescriptor>() }
 
-    private val typesUsedInInlineFunctions = LinkedList<MutableSet<String>>()
+    private val typesUsedInInlineFunctions by threadLocal { LinkedList<MutableSet<String>>() }
 
     fun enterDeclaration(descriptor: CallableDescriptor) {
         assert(descriptor.original !in inlineDeclarationSet) { "entered inlining cycle on $descriptor" }

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/InlineCache.kt

@@ -28,12 +28,14 @@ class InlineCache {
 }
 
 inline fun <K, V : Any> SLRUMap<K, V>.getOrPut(key: K, defaultValue: () -> V): V {
-    val value = get(key)
-    return if (value == null) {
-        val answer = defaultValue()
-        put(key, answer)
-        answer
-    } else {
-        value
+    synchronized(this) {
+        val value = get(key)
+        return if (value == null) {
+            val answer = defaultValue()
+            put(key, answer)
+            answer
+        } else {
+            value
+        }
     }
 }

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/InlineCodegen.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.codegen.inline
 
 import com.intellij.psi.PsiElement
-import com.intellij.util.ArrayUtil
 import org.jetbrains.kotlin.builtins.StandardNames
 import org.jetbrains.kotlin.codegen.*
 import org.jetbrains.kotlin.codegen.AsmUtil.isPrimitive
@@ -599,14 +598,6 @@ abstract class InlineCodegen<out T : BaseExpressionCodegen>(
             return (directMember as? ImportedFromObjectCallableDescriptor<*>)?.callableFromObject ?: directMember
         }
 
-        private fun cloneMethodNode(methodNode: MethodNode): MethodNode {
-            methodNode.instructions.resetLabels()
-            return MethodNode(
-                Opcodes.API_VERSION, methodNode.access, methodNode.name, methodNode.desc, methodNode.signature,
-                ArrayUtil.toStringArray(methodNode.exceptions)
-            ).also(methodNode::accept)
-        }
-
         private fun doCreateMethodNodeFromCompiled(
             callableDescriptor: CallableMemberDescriptor,
             state: GenerationState,

compiler/backend/src/org/jetbrains/kotlin/codegen/inline/inlineCodegenUtils.kt

@@ -625,3 +625,13 @@ fun MethodNode.preprocessSuspendMarkers(forInline: Boolean, keepFakeContinuation
         }
     }
 }
+
+fun cloneMethodNode(methodNode: MethodNode): MethodNode {
+    synchronized(methodNode) {
+        methodNode.instructions.resetLabels()
+        return MethodNode(
+            Opcodes.API_VERSION, methodNode.access, methodNode.name, methodNode.desc, methodNode.signature,
+            methodNode.exceptions.toTypedArray()
+        ).also(methodNode::accept)
+    }
+}

compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/CapturedVarsOptimizationMethodTransformer.kt

@@ -57,6 +57,8 @@ class CapturedVarsOptimizationMethodTransformer : MethodTransformer() {
         override fun onUseAsTainted() {
             hazard = true
         }
+
+        fun canRewrite() = !hazard && initCallInsn != null
     }
 
     private class Transformer(private val internalClassName: String, private val methodNode: MethodNode) {
@@ -72,7 +74,7 @@ class CapturedVarsOptimizationMethodTransformer : MethodTransformer() {
             assignLocalVars(frames)
 
             for (refValue in refValues) {
-                if (!refValue.hazard) {
+                if (refValue.canRewrite()) {
                     rewriteRefValue(refValue)
                 }
             }

compiler/backend/src/org/jetbrains/kotlin/codegen/state/BuilderFactoryForDuplicateClassNameDiagnostics.kt

@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.diagnostics.DiagnosticSink
 import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.ErrorsJvm
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin
+import java.util.concurrent.ConcurrentHashMap
 
 
 class BuilderFactoryForDuplicateClassNameDiagnostics(
@@ -29,7 +30,7 @@ class BuilderFactoryForDuplicateClassNameDiagnostics(
         private val diagnostics: DiagnosticSink
 ) : ClassNameCollectionClassBuilderFactory(builderFactory) {
 
-    private val className = hashMapOf<String, JvmDeclarationOrigin> ()
+    private val className = ConcurrentHashMap<String, JvmDeclarationOrigin>()
 
     override fun handleClashingNames(internalName: String, origin: JvmDeclarationOrigin) {
         val another = className.getOrPut(internalName, { origin })

compiler/build.gradle.kts

@@ -49,7 +49,6 @@ dependencies {
     testCompile(projectTests(":compiler:fir:raw-fir:light-tree2fir"))
     testCompile(projectTests(":compiler:fir:fir2ir"))
     testCompile(projectTests(":compiler:fir:analysis-tests:legacy-fir-tests"))
-    testCompile(projectTests(":compiler:visualizer"))
     testCompile(projectTests(":generators:test-generator"))
     testCompile(project(":compiler:ir.ir2cfg"))
     testCompile(project(":compiler:ir.tree")) // used for deepCopyWithSymbols call that is removed by proguard from the compiler TODO: make it more straightforward

compiler/builtins-serializer/src/org/jetbrains/kotlin/serialization/builtins/run.kt

@@ -42,6 +42,8 @@ found top-level declarations to <destination dir> (*.kotlin_builtins files)"""
     assert(missing.isEmpty()) { "These source directories are missing: $missing" }
 
     BuiltInsSerializer(dependOnOldBuiltIns = false).serialize(destDir, srcDirs, listOf()) { totalSize, totalFiles ->
-        println("Total bytes written: $totalSize to $totalFiles files")
+        if (System.getProperty("kotlin.builtins.serializer.log") == "true") {
+            println("Total bytes written: $totalSize to $totalFiles files")
+        }
     }
 }

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JVMCompilerArguments.kt

@@ -74,7 +74,7 @@ class K2JVMCompilerArguments : CommonCompilerArguments() {
     @Argument(
         value = "-jvm-target",
         valueDescription = "<version>",
-        description = "Target version of the generated JVM bytecode (1.6 (DEPRECATED), 1.8, 9, 10, 11, 12, 13, 14 or 15), default is 1.8"
+        description = "Target version of the generated JVM bytecode (1.6 (DEPRECATED), 1.8, 9, 10, 11, 12, 13, 14, 15 or 16), default is 1.8"
     )
     var jvmTarget: String? by NullableStringFreezableVar(JvmTarget.DEFAULT.description)
 
@@ -84,8 +84,12 @@ class K2JVMCompilerArguments : CommonCompilerArguments() {
 
     // Advanced options
 
+    @DeprecatedOption(removeAfter = "1.5", level = DeprecationLevel.WARNING)
     @GradleOption(DefaultValues.BooleanFalseDefault::class)
-    @Argument(value = "-Xuse-ir", description = "Use the IR backend")
+    @Argument(
+        value = "-Xuse-ir",
+        description = "Use the IR backend. This option has no effect unless the language version less than 1.5 is used"
+    )
     var useIR: Boolean by FreezableVar(false)
 
     @GradleOption(DefaultValues.BooleanFalseDefault::class)
@@ -489,6 +493,7 @@ default: `indy-with-constants` for JVM target 9 or greater, `inline` otherwise""
         result[JvmAnalysisFlags.enableJvmPreview] = enableJvmPreview
         result[AnalysisFlags.allowUnstableDependencies] = allowUnstableDependencies || useFir
         result[JvmAnalysisFlags.disableUltraLightClasses] = disableUltraLightClasses
+        result[JvmAnalysisFlags.useIR] = useIR
         return result
     }
 

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/CliKotlinAsJavaSupport.kt

@@ -13,6 +13,7 @@ import com.intellij.psi.search.PsiSearchScopeUtil
 import com.intellij.util.SmartList
 import org.jetbrains.kotlin.asJava.KotlinAsJavaSupport
 import org.jetbrains.kotlin.asJava.classes.*
+import org.jetbrains.kotlin.config.JvmAnalysisFlags
 import org.jetbrains.kotlin.descriptors.PackageViewDescriptor
 import org.jetbrains.kotlin.fileClasses.javaFileFacadeFqName
 import org.jetbrains.kotlin.load.java.components.FilesByFacadeFqNameIndexer
@@ -109,7 +110,7 @@ class CliKotlinAsJavaSupport(
     }
 
     override fun getLightClass(classOrObject: KtClassOrObject): KtLightClass? =
-        KtLightClassForSourceDeclaration.create(classOrObject)
+        KtLightClassForSourceDeclaration.create(classOrObject, traceHolder.languageVersionSettings.getFlag(JvmAnalysisFlags.jvmDefaultMode))
 
     override fun getLightClassForScript(script: KtScript): KtLightClassForScript? =
         KtLightClassForScript.create(script)

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinCoreEnvironment.kt

@@ -283,7 +283,7 @@ class KotlinCoreEnvironment private constructor(
 
     fun addKotlinSourceRoots(rootDirs: List<File>) {
         val roots = rootDirs.map { KotlinSourceRoot(it.absolutePath, isCommon = false) }
-        sourceFiles += createSourceFilesFromSourceRoots(configuration, project, roots)
+        sourceFiles += createSourceFilesFromSourceRoots(configuration, project, roots).toSet() - sourceFiles
     }
 
     fun createPackagePartProvider(scope: GlobalSearchScope): JvmPackagePartProvider {

compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmAnalysisFlags.kt

@@ -33,6 +33,9 @@ object JvmAnalysisFlags {
     @JvmStatic
     val enableJvmPreview by AnalysisFlag.Delegates.Boolean
 
+    @JvmStatic
+    val useIR by AnalysisFlag.Delegates.Boolean
+
     private object Delegates {
         object JavaTypeEnhancementStateWarnByDefault {
             operator fun provideDelegate(instance: Any?, property: KProperty<*>): AnalysisFlag.Delegate<JavaTypeEnhancementState> =

compiler/config.jvm/src/org/jetbrains/kotlin/config/JvmTarget.kt

@@ -32,6 +32,7 @@ enum class JvmTarget(
     JVM_13("13", Opcodes.V12 + 1),
     JVM_14("14", Opcodes.V12 + 2),
     JVM_15("15", Opcodes.V12 + 3),
+    JVM_16("16", Opcodes.V12 + 4),
     ;
 
     companion object {

compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java

@@ -750,6 +750,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/syntheticPropertiesWrongImplicitReceiver.kt");
         }
 
+        @TestMetadata("twoLocalLambdasWithSameName.kt")
+        public void testTwoLocalLambdasWithSameName() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/twoLocalLambdasWithSameName.kt");
+        }
+
         @TestMetadata("typeAliasWithNotNullBound.kt")
         public void testTypeAliasWithNotNullBound() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/typeAliasWithNotNullBound.kt");

compiler/fir/analysis-tests/testData/enhancement/jsr305/NonNullNever.fir.txt

@@ -3,9 +3,9 @@
 
 }
 public open class NonNullNever : R|kotlin/Any| {
-    @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) public open field field: R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) public open field field: R|kotlin/String?|
 
-    @R|MyNullable|() public open fun foo(@R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) x: R|@EnhancedNullability kotlin/String?|, @R|MyNullable|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String?|
+    @R|MyNullable|() public open fun foo(@R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) x: R|kotlin/String?|, @R|MyNullable|() y: R|kotlin/CharSequence?|): R|kotlin/String?|
 
     public constructor(): R|NonNullNever|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/Simple.fir.txt

@@ -1,7 +1,7 @@
 public open class Simple : R|kotlin/Any| {
-    @R|javax/annotation/Nullable|() public open field field: R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    @R|javax/annotation/Nullable|() public open fun foo(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open fun foo(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|kotlin/String?|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/Strange.fir.txt

@@ -1,7 +1,7 @@
 public open class Strange : R|kotlin/Any| {
     @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.UNKNOWN|()) public open field field: R|ft<kotlin/String, kotlin/String?>|
 
-    @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.MAYBE|()) public open fun foo(@R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.ALWAYS|()) x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.MAYBE|()) public open fun foo(@R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.ALWAYS|()) x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/Nonnull|(R|javax/annotation/meta/When.NEVER|()) y: R|kotlin/CharSequence?|): R|kotlin/String?|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/FieldsAreNullable.fir.txt

@@ -1,9 +1,9 @@
 @R|FieldsAreNullable|() public open class A : R|kotlin/Any| {
-    public open field field: R|@EnhancedNullability kotlin/String?|
+    public open field field: R|kotlin/String?|
 
     @R|javax/annotation/Nonnull|() public open field nonNullField: R|@EnhancedNullability kotlin/String|
 
-    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
+    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ForceFlexibility.fir.txt

@@ -1,5 +1,5 @@
 @R|spr/NonNullApi|() public open class A : R|kotlin/Any| {
-    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|spr/Nullable|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
+    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|spr/Nullable|() y: R|kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
 
     @R|spr/ForceFlexibility|() public open fun bar(x: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() y: R|@EnhancedNullability kotlin/CharSequence|): R|ft<kotlin/String, kotlin/String?>|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/NullabilityFromOverridden.fir.txt

@@ -5,9 +5,9 @@
 
     public open fun foo3(x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
-    @R|javax/annotation/Nullable|() public open fun bar1(@R|javax/annotation/Nullable|() x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open fun bar1(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
-    @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
     public open fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
@@ -21,9 +21,9 @@
 
     public abstract fun foo3(x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/CharSequence|
 
-    @R|javax/annotation/Nullable|() public abstract fun bar1(@R|javax/annotation/Nullable|() x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/CharSequence?|
+    @R|javax/annotation/Nullable|() public abstract fun bar1(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/CharSequence?|
 
-    @R|javax/annotation/Nullable|() public abstract fun bar2(@R|javax/annotation/Nullable|() x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/CharSequence?|
+    @R|javax/annotation/Nullable|() public abstract fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/CharSequence?|
 
     public abstract fun baz(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/CharSequence|
 
@@ -33,7 +33,7 @@
 
     @R|javax/annotation/Nonnull|() public open fun foo2(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
-    public open fun bar1(x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
+    public open fun bar1(x: R|kotlin/String?|): R|kotlin/String?|
 
     public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
@@ -45,9 +45,9 @@
 
     public open fun foo2(@R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 
-    public open fun bar1(x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
+    public open fun bar1(x: R|kotlin/String?|): R|kotlin/String?|
 
-    @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|@EnhancedNullability kotlin/String?|): R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open fun bar2(@R|javax/annotation/Nullable|() x: R|kotlin/String?|): R|kotlin/String?|
 
     public open fun baz(x: R|@EnhancedNullability kotlin/String|): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/OverridingDefaultQualifier.fir.txt

@@ -1,13 +1,13 @@
 @R|NonNullApi|() public open class A : R|kotlin/Any| {
     public open field field: R|@EnhancedNullability kotlin/String|
 
-    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
+    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
 
-    @R|NullableApi|() public open fun foobar(x: R|@EnhancedNullability kotlin/String?|, @R|NonNullApi|() y: R|@EnhancedNullability kotlin/CharSequence|): R|@EnhancedNullability kotlin/String?|
+    @R|NullableApi|() public open fun foobar(x: R|kotlin/String?|, @R|NonNullApi|() y: R|@EnhancedNullability kotlin/CharSequence|): R|kotlin/String?|
 
     public open fun bar(): R|@EnhancedNullability kotlin/String|
 
-    @R|javax/annotation/Nullable|() public open fun baz(): R|ft<@EnhancedNullability kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, @EnhancedNullability kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
+    @R|javax/annotation/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
 
     public constructor(): R|A|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefault.fir.txt

@@ -1,7 +1,7 @@
 @R|javax/annotation/ParametersAreNonnullByDefault|() public open class A : R|kotlin/Any| {
-    @R|javax/annotation/Nullable|() public open field field: R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    public open fun foo(q: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
+    public open fun foo(q: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/ParametersAreNonnullByDefaultPackage.fir.txt

@@ -1,7 +1,7 @@
 public open class A : R|kotlin/Any| {
-    @R|javax/annotation/Nullable|() public open field field: R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
+    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 
@@ -9,9 +9,9 @@ public open class A : R|kotlin/Any| {
 
 }
 public open class A2 : R|kotlin/Any| {
-    @R|javax/annotation/Nullable|() public open field field: R|@EnhancedNullability kotlin/String?|
+    @R|javax/annotation/Nullable|() public open field field: R|kotlin/String?|
 
-    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
+    public open fun foo(q: R|ft<kotlin/String, kotlin/String?>|, @R|javax/annotation/Nonnull|() x: R|@EnhancedNullability kotlin/String|, @R|javax/annotation/CheckForNull|() y: R|kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
 
     @R|javax/annotation/Nonnull|() public open fun bar(): R|@EnhancedNullability kotlin/String|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullable.fir.txt

@@ -1,11 +1,11 @@
 @R|spr/NonNullApi|() public open class A : R|kotlin/Any| {
     public open field field: R|ft<kotlin/String, kotlin/String?>|
 
-    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|spr/Nullable|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
+    public open fun foo(x: R|@EnhancedNullability kotlin/String|, @R|spr/Nullable|() y: R|kotlin/CharSequence?|): R|@EnhancedNullability kotlin/String|
 
     public open fun bar(): R|@EnhancedNullability kotlin/String|
 
-    @R|spr/Nullable|() public open fun baz(): R|ft<@EnhancedNullability kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, @EnhancedNullability kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
+    @R|spr/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
 
     public constructor(): R|A|
 

compiler/fir/analysis-tests/testData/enhancement/jsr305/typeQualifierDefault/SpringNullablePackage.fir.txt

@@ -1,11 +1,11 @@
 public open class A : R|kotlin/Any| {
     public open field field: R|ft<kotlin/String, kotlin/String?>|
 
-    public open fun foo(x: R|ft<kotlin/String, kotlin/String?>|, @R|spr/Nullable|() y: R|@EnhancedNullability kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
+    public open fun foo(x: R|ft<kotlin/String, kotlin/String?>|, @R|spr/Nullable|() y: R|kotlin/CharSequence?|): R|ft<kotlin/String, kotlin/String?>|
 
     public open fun bar(): R|ft<kotlin/String, kotlin/String?>|
 
-    @R|spr/Nullable|() public open fun baz(): R|ft<@EnhancedNullability kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, @EnhancedNullability kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
+    @R|spr/Nullable|() public open fun baz(): R|ft<kotlin/collections/MutableList<ft<kotlin/String, kotlin/String?>>?, kotlin/collections/List<ft<kotlin/String, kotlin/String?>>?>|
 
     public constructor(): R|test/A|
 

compiler/fir/analysis-tests/testData/resolve/callResolution/twoLocalLambdasWithSameName.fir.txt

@@ -0,0 +1,19 @@
+FILE: twoLocalLambdasWithSameName.kt
+    public abstract interface R : R|kotlin/Any| {
+    }
+    public final fun takeInt(x: R|kotlin/Int|): R|kotlin/Unit| {
+    }
+    public final fun test(fn: R|R.() -> kotlin/String|): R|kotlin/Unit| {
+        lval renderer: R|<anonymous>| = object : R|R| {
+            private constructor(): R|<anonymous>| {
+                super<R|kotlin/Any|>()
+            }
+
+            public final fun render(fn: R|R.() -> kotlin/Int|): R|kotlin/Unit| {
+                lval result: R|kotlin/Int| = R|<local>/fn|.R|SubstitutionOverride<kotlin/Function1.invoke: R|kotlin/Int|>|(this@R|/<anonymous>|)
+                R|/takeInt|(R|<local>/result|)
+            }
+
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolve/callResolution/twoLocalLambdasWithSameName.kt

@@ -0,0 +1,13 @@
+// ISSUE: KT-45316
+interface R
+
+fun takeInt(x: Int) {}
+
+fun test(fn: R.() -> String) { // (1)
+    val renderer = object : R {
+        fun render(fn: R.() -> Int) { // (2)
+            val result = fn()
+            takeInt(result)
+        }
+    }
+}

compiler/fir/analysis-tests/testData/resolve/diagnostics/annotationArgumentKClassLiteralTypeError.fir.txt

@@ -9,7 +9,7 @@ FILE: annotationArgumentKClassLiteralTypeError.kt
 
     }
     public final val <reified T> R|T|.test: R|kotlin/Any|
-        public get(): R|<anonymous><T>| {
+        public inline get(): R|<anonymous><T>| {
             ^ @R|Ann|(<implicitArrayOf>(<getClass>(R|T|), <getClass>(Q|kotlin/Array|))) object : R|kotlin/Any| {
                 private constructor(): R|<anonymous><T>| {
                     super<R|kotlin/Any|>()

compiler/fir/analysis-tests/testData/resolve/inference/nullableIntegerLiteralType.fir.txt

@@ -11,7 +11,7 @@ FILE: nullableIntegerLiteralType.kt
             }
         }
 
-        <Inapplicable(INAPPLICABLE): /takeInt>#(R|<local>/x|)
+        <Inapplicable(MAY_THROW_RUNTIME_ERROR): /takeInt>#(R|<local>/x|)
     }
     public final fun test_2(b: R|kotlin/Boolean|, y: R|kotlin/Int|): R|kotlin/Unit| {
         lval x: R|kotlin/Int?| = when () {
@@ -23,5 +23,5 @@ FILE: nullableIntegerLiteralType.kt
             }
         }
 
-        <Inapplicable(INAPPLICABLE): /takeInt>#(R|<local>/x|)
+        <Inapplicable(MAY_THROW_RUNTIME_ERROR): /takeInt>#(R|<local>/x|)
     }

compiler/fir/analysis-tests/testData/resolve/kt41984.fir.txt

@@ -21,6 +21,6 @@ FILE: main.kt
     }
     public final fun test_1(b: R|B<kotlin/Int>|, x: R|kotlin/Int|, inv: R|Inv<kotlin/Int>|): R|kotlin/Unit| {
         R|<local>/b|.R|SubstitutionOverride</B.take: R|kotlin/String|>|(R|<local>/x|)
-        R|<local>/b|.<Inapplicable(INAPPLICABLE): /B.take>#(Null(null))
+        R|<local>/b|.<Inapplicable(MAY_THROW_RUNTIME_ERROR): /B.take>#(Null(null))
         R|<local>/b|.R|SubstitutionOverride</B.takeInv: R|kotlin/String|>|(R|<local>/inv|)
     }

compiler/fir/analysis-tests/testData/resolveWithStdlib/contracts/fromSource/bad/returnsImplies/propertyGetter.kt

@@ -11,8 +11,8 @@ fun Any?.isNotNull(): Boolean {
 @OptIn(ExperimentalContracts::class)
 val Any?.isNotNull: Boolean
     get() {
-        <!WRONG_IMPLIES_CONDITION!>contract {
+        contract {
             returns(true) implies (this@isNotNull != null)
-        }<!>
+        }
         return this@isNotNull != null
     }

compiler/fir/analysis-tests/testData/resolveWithStdlib/contracts/fromSource/good/returnsImplies/propertyAccessors.kt

@@ -6,16 +6,16 @@ interface A {
 
 var Any?.isNotNull: Boolean
     get() {
-        <!WRONG_IMPLIES_CONDITION!>contract {
+        contract {
             returns(true) implies (this@isNotNull != null)
-        }<!>
+        }
         return this != null
     }
     set(value) {
-        <!WRONG_IMPLIES_CONDITION!>contract {
+        contract {
             returns() implies (this@isNotNull != null)
             require(this != null)
-        }<!>
+        }
     }
 
 fun test_1(a: A?) {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -869,6 +869,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/syntheticPropertiesWrongImplicitReceiver.kt");
             }
 
+            @Test
+            @TestMetadata("twoLocalLambdasWithSameName.kt")
+            public void testTwoLocalLambdasWithSameName() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/twoLocalLambdasWithSameName.kt");
+            }
+
             @Test
             @TestMetadata("typeAliasWithNotNullBound.kt")
             public void testTypeAliasWithNotNullBound() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -876,6 +876,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/syntheticPropertiesWrongImplicitReceiver.kt");
             }
 
+            @Test
+            @TestMetadata("twoLocalLambdasWithSameName.kt")
+            public void testTwoLocalLambdasWithSameName() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/callResolution/twoLocalLambdasWithSameName.kt");
+            }
+
             @Test
             @TestMetadata("typeAliasWithNotNullBound.kt")
             public void testTypeAliasWithNotNullBound() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -2091,6 +2091,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/backingField/kt782packageLevel.kt");
             }
 
+            @Test
+            @TestMetadata("LocalDeclarations.kt")
+            public void testLocalDeclarations() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/backingField/LocalDeclarations.kt");
+            }
+
             @Test
             @TestMetadata("SetterWithExplicitType.kt")
             public void testSetterWithExplicitType() throws Exception {
@@ -10078,28 +10084,6 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/functionLiterals/return/unresolvedReferenceInReturnBlock.kt");
                 }
             }
-
-            @Nested
-            @TestMetadata("compiler/testData/diagnostics/tests/functionLiterals/suspend")
-            @TestDataPath("$PROJECT_ROOT")
-            public class Suspend {
-                @Test
-                public void testAllFilesPresentInSuspend() throws Exception {
-                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/diagnostics/tests/functionLiterals/suspend"), Pattern.compile("^(.+)\\.kt$"), Pattern.compile("^(.+)\\.fir\\.kts?$"), true);
-                }
-
-                @Test
-                @TestMetadata("disabled.kt")
-                public void testDisabled() throws Exception {
-                    runTest("compiler/testData/diagnostics/tests/functionLiterals/suspend/disabled.kt");
-                }
-
-                @Test
-                @TestMetadata("enabled.kt")
-                public void testEnabled() throws Exception {
-                    runTest("compiler/testData/diagnostics/tests/functionLiterals/suspend/enabled.kt");
-                }
-            }
         }
 
         @Nested
@@ -12574,6 +12558,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/inference/capturedTypes/starProjectionRegression.kt");
                 }
 
+                @Test
+                @TestMetadata("substituteCapturedTypesWithTypeVariables.kt")
+                public void testSubstituteCapturedTypesWithTypeVariables() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/inference/capturedTypes/substituteCapturedTypesWithTypeVariables.kt");
+                }
+
                 @Test
                 @TestMetadata("topLevelCapturingInsideReturnType.kt")
                 public void testTopLevelCapturingInsideReturnType() throws Exception {
@@ -25745,6 +25735,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/smartCasts/threeImplicitReceivers.kt");
             }
 
+            @Test
+            @TestMetadata("throwInTry.kt")
+            public void testThrowInTry() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/smartCasts/throwInTry.kt");
+            }
+
             @Test
             @TestMetadata("twoImplicitReceivers.kt")
             public void testTwoImplicitReceivers() throws Exception {
@@ -29591,12 +29587,6 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/unsignedTypes/unsignedLiteralsInsideConstVals.kt");
             }
 
-            @Test
-            @TestMetadata("unsignedLiteralsOn1_2.kt")
-            public void testUnsignedLiteralsOn1_2() throws Exception {
-                runTest("compiler/testData/diagnostics/tests/unsignedTypes/unsignedLiteralsOn1_2.kt");
-            }
-
             @Test
             @TestMetadata("unsignedLiteralsOverflowSignedBorder.kt")
             public void testUnsignedLiteralsOverflowSignedBorder() throws Exception {
@@ -33613,12 +33603,6 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalOnWholeModule.kt");
             }
 
-            @Test
-            @TestMetadata("experimentalUnsignedLiterals.kt")
-            public void testExperimentalUnsignedLiterals() throws Exception {
-                runTest("compiler/testData/diagnostics/testsWithStdLib/experimental/experimentalUnsignedLiterals.kt");
-            }
-
             @Test
             @TestMetadata("fullFqNameUsage.kt")
             public void testFullFqNameUsage() throws Exception {

compiler/fir/checkers/checkers-component-generator/src/org/jetbrains/kotlin/fir/checkers/generator/diagnostics/FirDiagnosticsList.kt

@@ -160,6 +160,10 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
             parameter<KtModifierKeywordToken>("modifier2")
         }
         val REDUNDANT_OPEN_IN_INTERFACE by warning<FirSourceElement, KtModifierListOwner>(PositioningStrategy.OPEN_MODIFIER)
+        val WRONG_MODIFIER_TARGET by error<FirSourceElement, PsiElement> {
+            parameter<KtModifierKeywordToken>("modifier")
+            parameter<String>("target")
+        }
     }
 
     val INLINE_CLASSES by object : DiagnosticGroup("Inline classes") {
@@ -231,7 +235,6 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
             parameter<Int>("expectedCount")
             parameter<FirClassLikeSymbol<*>>("classifier")
         }
-        val NO_TYPE_FOR_TYPE_PARAMETER by error<FirSourceElement, PsiElement>()
         val TYPE_PARAMETERS_IN_OBJECT by error<FirSourceElement, PsiElement>()
         val ILLEGAL_PROJECTION_USAGE by error<FirSourceElement, PsiElement>()
         val TYPE_PARAMETERS_IN_ENUM by error<FirSourceElement, PsiElement>()
@@ -245,11 +248,24 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val TYPE_PARAMETER_IN_CATCH_CLAUSE by error<FirSourceElement, PsiElement>()
         val GENERIC_THROWABLE_SUBCLASS by error<FirSourceElement, KtTypeParameterList>()
         val INNER_CLASS_OF_GENERIC_THROWABLE_SUBCLASS by error<FirSourceElement, KtClassOrObject>(PositioningStrategy.DECLARATION_NAME)
+
+        val KCLASS_WITH_NULLABLE_TYPE_PARAMETER_IN_SIGNATURE by error<FirSourceElement, KtNamedDeclaration>(PositioningStrategy.DECLARATION_NAME) {
+            parameter<FirTypeParameterSymbol>("typeParameter")
+        }
+
+        val TYPE_PARAMETER_AS_REIFIED by error<FirSourceElement, PsiElement> {
+            parameter<FirTypeParameterSymbol>("typeParameter")
+        }
     }
 
     val REFLECTION by object : DiagnosticGroup("Reflection") {
+        val CALLABLE_REFERENCE_LHS_NOT_A_CLASS by error<FirSourceElement, KtExpression>()
+
         val CLASS_LITERAL_LHS_NOT_A_CLASS by error<FirSourceElement, KtExpression>()
         val NULLABLE_TYPE_IN_CLASS_LITERAL_LHS by error<FirSourceElement, KtExpression>()
+        val EXPRESSION_OF_NULLABLE_TYPE_IN_CLASS_LITERAL_LHS by error<FirSourceElement, PsiElement> {
+            parameter<ConeKotlinType>("lhsType")
+        }
     }
 
     val OVERRIDES by object : DiagnosticGroup("overrides") {
@@ -341,6 +357,7 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val FORBIDDEN_VARARG_PARAMETER_TYPE by error<FirSourceElement, KtParameter>(PositioningStrategy.PARAMETER_VARARG_MODIFIER) {
             parameter<ConeKotlinType>("varargParameterType")
         }
+        val VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION by error<FirSourceElement, KtParameter>()
     }
 
     val PROPERTIES_AND_ACCESSORS by object : DiagnosticGroup("Properties & accessors") {
@@ -410,6 +427,12 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val VAL_REASSIGNMENT by error<FirSourceElement, KtExpression> {
             parameter<FirPropertySymbol>("variable")
         }
+        val VAL_REASSIGNMENT_VIA_BACKING_FIELD by warning<FirSourceElement, KtExpression> {
+            parameter<FirPropertySymbol>("variable")
+        }
+        val VAL_REASSIGNMENT_VIA_BACKING_FIELD_ERROR by error<FirSourceElement, KtExpression> {
+            parameter<FirPropertySymbol>("variable")
+        }
         val WRONG_INVOCATION_KIND by warning<FirSourceElement, PsiElement> {
             parameter<AbstractFirBasedSymbol<*>>("declaration")
             parameter<EventOccurrencesRange>("requiredRange")
@@ -448,6 +471,15 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         val INVALID_IF_AS_EXPRESSION by error<FirSourceElement, KtIfExpression>(PositioningStrategy.IF_EXPRESSION)
     }
 
+    val CONTEXT_TRACKING by object : DiagnosticGroup("Context tracking") {
+        val TYPE_PARAMETER_IS_NOT_AN_EXPRESSION by error<FirSourceElement, KtSimpleNameExpression> {
+            parameter<FirTypeParameterSymbol>("typeParameter")
+        }
+        val TYPE_PARAMETER_ON_LHS_OF_DOT by error<FirSourceElement, KtSimpleNameExpression> {
+            parameter<FirTypeParameterSymbol>("typeParameter")
+        }
+    }
+
     val FUNCTION_CONTRACTS by object : DiagnosticGroup("Function contracts") {
         val ERROR_IN_CONTRACT_DESCRIPTION by error<FirSourceElement, KtElement>(PositioningStrategy.SELECTOR_BY_QUALIFIED) {
             parameter<String>("reason")

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/diagnostics/FirErrors.kt

@@ -145,6 +145,7 @@ object FirErrors {
     val DEPRECATED_MODIFIER_PAIR by error2<FirSourceElement, PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
     val INCOMPATIBLE_MODIFIERS by error2<FirSourceElement, PsiElement, KtModifierKeywordToken, KtModifierKeywordToken>()
     val REDUNDANT_OPEN_IN_INTERFACE by warning0<FirSourceElement, KtModifierListOwner>(SourceElementPositioningStrategies.OPEN_MODIFIER)
+    val WRONG_MODIFIER_TARGET by error2<FirSourceElement, PsiElement, KtModifierKeywordToken, String>()
 
     // Inline classes
     val INLINE_CLASS_NOT_TOP_LEVEL by error0<FirSourceElement, KtDeclaration>(SourceElementPositioningStrategies.INLINE_OR_VALUE_MODIFIER)
@@ -182,7 +183,6 @@ object FirErrors {
     val UPPER_BOUND_VIOLATED by error2<FirSourceElement, PsiElement, FirTypeParameterSymbol, ConeKotlinType>()
     val TYPE_ARGUMENTS_NOT_ALLOWED by error0<FirSourceElement, PsiElement>()
     val WRONG_NUMBER_OF_TYPE_ARGUMENTS by error2<FirSourceElement, PsiElement, Int, FirClassLikeSymbol<*>>()
-    val NO_TYPE_FOR_TYPE_PARAMETER by error0<FirSourceElement, PsiElement>()
     val TYPE_PARAMETERS_IN_OBJECT by error0<FirSourceElement, PsiElement>()
     val ILLEGAL_PROJECTION_USAGE by error0<FirSourceElement, PsiElement>()
     val TYPE_PARAMETERS_IN_ENUM by error0<FirSourceElement, PsiElement>()
@@ -193,10 +193,14 @@ object FirErrors {
     val TYPE_PARAMETER_IN_CATCH_CLAUSE by error0<FirSourceElement, PsiElement>()
     val GENERIC_THROWABLE_SUBCLASS by error0<FirSourceElement, KtTypeParameterList>()
     val INNER_CLASS_OF_GENERIC_THROWABLE_SUBCLASS by error0<FirSourceElement, KtClassOrObject>(SourceElementPositioningStrategies.DECLARATION_NAME)
+    val KCLASS_WITH_NULLABLE_TYPE_PARAMETER_IN_SIGNATURE by error1<FirSourceElement, KtNamedDeclaration, FirTypeParameterSymbol>(SourceElementPositioningStrategies.DECLARATION_NAME)
+    val TYPE_PARAMETER_AS_REIFIED by error1<FirSourceElement, PsiElement, FirTypeParameterSymbol>()
 
     // Reflection
+    val CALLABLE_REFERENCE_LHS_NOT_A_CLASS by error0<FirSourceElement, KtExpression>()
     val CLASS_LITERAL_LHS_NOT_A_CLASS by error0<FirSourceElement, KtExpression>()
     val NULLABLE_TYPE_IN_CLASS_LITERAL_LHS by error0<FirSourceElement, KtExpression>()
+    val EXPRESSION_OF_NULLABLE_TYPE_IN_CLASS_LITERAL_LHS by error1<FirSourceElement, PsiElement, ConeKotlinType>()
 
     // overrides
     val NOTHING_TO_OVERRIDE by error1<FirSourceElement, KtModifierListOwner, FirMemberDeclaration>(SourceElementPositioningStrategies.OVERRIDE_MODIFIER)
@@ -231,6 +235,7 @@ object FirErrors {
     val USELESS_VARARG_ON_PARAMETER by warning0<FirSourceElement, KtParameter>()
     val MULTIPLE_VARARG_PARAMETERS by error0<FirSourceElement, KtParameter>(SourceElementPositioningStrategies.PARAMETER_VARARG_MODIFIER)
     val FORBIDDEN_VARARG_PARAMETER_TYPE by error1<FirSourceElement, KtParameter, ConeKotlinType>(SourceElementPositioningStrategies.PARAMETER_VARARG_MODIFIER)
+    val VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION by error0<FirSourceElement, KtParameter>()
 
     // Properties & accessors
     val ABSTRACT_PROPERTY_IN_NON_ABSTRACT_CLASS by error2<FirSourceElement, KtModifierListOwner, FirMemberDeclaration, FirMemberDeclaration>(SourceElementPositioningStrategies.MODALITY_MODIFIER)
@@ -270,6 +275,8 @@ object FirErrors {
     // Control flow diagnostics
     val UNINITIALIZED_VARIABLE by error1<FirSourceElement, KtSimpleNameExpression, FirPropertySymbol>()
     val VAL_REASSIGNMENT by error1<FirSourceElement, KtExpression, FirPropertySymbol>()
+    val VAL_REASSIGNMENT_VIA_BACKING_FIELD by warning1<FirSourceElement, KtExpression, FirPropertySymbol>()
+    val VAL_REASSIGNMENT_VIA_BACKING_FIELD_ERROR by error1<FirSourceElement, KtExpression, FirPropertySymbol>()
     val WRONG_INVOCATION_KIND by warning3<FirSourceElement, PsiElement, AbstractFirBasedSymbol<*>, EventOccurrencesRange, EventOccurrencesRange>()
     val LEAKED_IN_PLACE_LAMBDA by error1<FirSourceElement, PsiElement, AbstractFirBasedSymbol<*>>()
     val WRONG_IMPLIES_CONDITION by warning0<FirSourceElement, PsiElement>()
@@ -284,6 +291,10 @@ object FirErrors {
     val NO_ELSE_IN_WHEN by error1<FirSourceElement, KtWhenExpression, List<WhenMissingCase>>(SourceElementPositioningStrategies.WHEN_EXPRESSION)
     val INVALID_IF_AS_EXPRESSION by error0<FirSourceElement, KtIfExpression>(SourceElementPositioningStrategies.IF_EXPRESSION)
 
+    // Context tracking
+    val TYPE_PARAMETER_IS_NOT_AN_EXPRESSION by error1<FirSourceElement, KtSimpleNameExpression, FirTypeParameterSymbol>()
+    val TYPE_PARAMETER_ON_LHS_OF_DOT by error1<FirSourceElement, KtSimpleNameExpression, FirTypeParameterSymbol>()
+
     // Function contracts
     val ERROR_IN_CONTRACT_DESCRIPTION by error1<FirSourceElement, KtElement, String>(SourceElementPositioningStrategies.SELECTOR_BY_QUALIFIED)
 

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/FirReturnsImpliesAnalyzer.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.fir.contracts.coneEffects
 import org.jetbrains.kotlin.fir.contracts.description.*
 import org.jetbrains.kotlin.fir.declarations.FirContractDescriptionOwner
 import org.jetbrains.kotlin.fir.declarations.FirFunction
+import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.resolve.dfa.*
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.BlockExitNode
@@ -23,6 +24,7 @@ import org.jetbrains.kotlin.fir.resolve.dfa.cfg.CFGNode
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.ControlFlowGraph
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.JumpNode
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirPropertyAccessorSymbol
 import org.jetbrains.kotlin.fir.typeContext
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.coneType
@@ -61,7 +63,7 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
 
         effects.forEach { effect ->
             val wrongCondition = graph.exitNode.previousCfgNodes.any {
-                isWrongConditionOnNode(it, effect as ConeConditionalEffectDeclaration, function, logicSystem, dataFlowInfo)
+                isWrongConditionOnNode(it, effect as ConeConditionalEffectDeclaration, function, logicSystem, dataFlowInfo, context)
             }
 
             if (wrongCondition) {
@@ -77,7 +79,8 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
         effectDeclaration: ConeConditionalEffectDeclaration,
         function: FirFunction<*>,
         logicSystem: LogicSystem<PersistentFlow>,
-        dataFlowInfo: DataFlowInfo
+        dataFlowInfo: DataFlowInfo,
+        context: CheckerContext
     ): Boolean {
         val effect = effectDeclaration.effect as ConeReturnsEffectDeclaration
         val builtinTypes = function.session.builtinTypes
@@ -92,7 +95,7 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
 
         if (isReturn && resultExpression is FirWhenExpression) {
             return node.collectBranchExits().any {
-                isWrongConditionOnNode(it, effectDeclaration, function, logicSystem, dataFlowInfo)
+                isWrongConditionOnNode(it, effectDeclaration, function, logicSystem, dataFlowInfo, context)
             }
         }
 
@@ -110,15 +113,16 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
             }
         }
 
-        val conditionStatements =
-            effectDeclaration.condition.buildTypeStatements(function, logicSystem, dataFlowInfo.variableStorage, flow) ?: return false
+        val conditionStatements = effectDeclaration.condition.buildTypeStatements(
+            function, logicSystem, dataFlowInfo.variableStorage, flow, context
+        ) ?: return false
 
         for ((realVar, requiredTypeStatement) in conditionStatements) {
             val fixedRealVar = typeStatements.keys.find { it.identifier == realVar.identifier } ?: realVar
             val resultTypeStatement = typeStatements[fixedRealVar]
 
             val resultType = mutableListOf<ConeKotlinType>().apply {
-                addIfNotNull(function.getParameterType(fixedRealVar.identifier.symbol))
+                addIfNotNull(function.getParameterType(fixedRealVar.identifier.symbol, context))
                 if (resultTypeStatement != null) addAll(resultTypeStatement.exactType)
             }.let { typeContext.intersectTypesOrNull(it) }
 
@@ -154,11 +158,12 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
         function: FirFunction<*>,
         logicSystem: LogicSystem<*>,
         variableStorage: VariableStorage,
-        flow: Flow
+        flow: Flow,
+        context: CheckerContext
     ): MutableTypeStatements? = when (this) {
         is ConeBinaryLogicExpression -> {
-            val left = left.buildTypeStatements(function, logicSystem, variableStorage, flow)
-            val right = right.buildTypeStatements(function, logicSystem, variableStorage, flow)
+            val left = left.buildTypeStatements(function, logicSystem, variableStorage, flow, context)
+            val right = right.buildTypeStatements(function, logicSystem, variableStorage, flow, context)
             if (left != null && right != null) {
                 if (kind == LogicOperationKind.AND) {
                     left.apply { mergeTypeStatements(right) }
@@ -166,16 +171,16 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
             } else (left ?: right)
         }
         is ConeIsInstancePredicate -> {
-            val fir = function.getParameterSymbol(arg.parameterIndex).fir
+            val fir = function.getParameterSymbol(arg.parameterIndex, context).fir
             val realVar = variableStorage.getOrCreateRealVariable(flow, fir.symbol, fir)
             realVar?.to(simpleTypeStatement(realVar, !isNegated, type))?.let { mutableMapOf(it) }
         }
         is ConeIsNullPredicate -> {
-            val fir = function.getParameterSymbol(arg.parameterIndex).fir
+            val fir = function.getParameterSymbol(arg.parameterIndex, context).fir
             val realVar = variableStorage.getOrCreateRealVariable(flow, fir.symbol, fir)
             realVar?.to(simpleTypeStatement(realVar, isNegated, function.session.builtinTypes.anyType.type))?.let { mutableMapOf(it) }
         }
-        is ConeLogicalNot -> arg.buildTypeStatements(function, logicSystem, variableStorage, flow)
+        is ConeLogicalNot -> arg.buildTypeStatements(function, logicSystem, variableStorage, flow, context)
             ?.mapValuesTo(mutableMapOf()) { (_, value) -> value.invert() }
 
         else -> null
@@ -212,11 +217,31 @@ object FirReturnsImpliesAnalyzer : FirControlFlowChecker() {
         return nodes
     }
 
-    private fun FirFunction<*>.getParameterType(symbol: AbstractFirBasedSymbol<*>): ConeKotlinType? {
-        return (if (this.symbol == symbol) receiverTypeRef else valueParameters.find { it.symbol == symbol }?.returnTypeRef)?.coneType
+    private val CheckerContext.containingProperty: FirProperty?
+        get() = (containingDeclarations.asReversed().firstOrNull { it is FirProperty } as? FirProperty)
+
+    private fun FirFunction<*>.getParameterType(symbol: AbstractFirBasedSymbol<*>, context: CheckerContext): ConeKotlinType? {
+        val typeRef = if (this.symbol == symbol) {
+            if (symbol is FirPropertyAccessorSymbol) {
+                context.containingProperty?.receiverTypeRef
+            } else {
+                receiverTypeRef
+            }
+        } else {
+            valueParameters.find { it.symbol == symbol }?.returnTypeRef
+        }
+        return typeRef?.coneType
     }
 
-    private fun FirFunction<*>.getParameterSymbol(index: Int): AbstractFirBasedSymbol<*> {
-        return if (index == -1) this.symbol else this.valueParameters[index].symbol
+    private fun FirFunction<*>.getParameterSymbol(index: Int, context: CheckerContext): AbstractFirBasedSymbol<*> {
+        return if (index == -1) {
+            if (symbol !is FirPropertyAccessorSymbol) {
+                symbol
+            } else {
+                context.containingProperty?.symbol ?: symbol
+            }
+        } else {
+            this.valueParameters[index].symbol
+        }
     }
 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/cfa/PathAwareControlFlowInfo.kt

@@ -7,10 +7,7 @@ package org.jetbrains.kotlin.fir.analysis.cfa
 
 import kotlinx.collections.immutable.PersistentMap
 import kotlinx.collections.immutable.persistentMapOf
-import org.jetbrains.kotlin.fir.resolve.dfa.cfg.CFGNode
-import org.jetbrains.kotlin.fir.resolve.dfa.cfg.EdgeLabel
-import org.jetbrains.kotlin.fir.resolve.dfa.cfg.NormalPath
-import org.jetbrains.kotlin.fir.resolve.dfa.cfg.TryExpressionExitNode
+import org.jetbrains.kotlin.fir.resolve.dfa.cfg.*
 
 abstract class PathAwareControlFlowInfo<P : PathAwareControlFlowInfo<P, S>, S : ControlFlowInfo<S, *, *>>(
     map: PersistentMap<EdgeLabel, S>,
@@ -43,11 +40,24 @@ abstract class PathAwareControlFlowInfo<P : PathAwareControlFlowInfo<P, S>, S :
 
         val hasAbnormalLabels = map.keys.any { !it.isNormal }
         return if (hasAbnormalLabels) {
-            // { |-> ... l1 |-> I1, l2 |-> I2, ... }
+            // { |-> ..., l1 |-> I1, l2 |-> I2, ... }
             //   | l1         // path exit: if the given info has non-null labels, this acts like a filtering
-            // { |-> I1 }     // NB: remove the path info
+            // { |-> I1 }     // NB: remove the path label, except for uncaught exception path
             if (map.keys.contains(label)) {
-                constructor(persistentMapOf(NormalPath to map[label]!!))
+                if (label == UncaughtExceptionPath) {
+                    // Special case: uncaught exception path, which still represents an uncaught exception path
+                    // Target node is most likely fun/init exit, and we should keep info separated.
+                    constructor(persistentMapOf(label to map[label]!!))
+                } else {
+                    // { |-> I }
+                    //   | l1       // e.g., enter to proxy1 with l1
+                    // { l1 -> I }
+                    //   ...
+                    // { |-> ..., l1 -> I', ... }
+                    //   | l1       // e.g., exit proxy1 with l1
+                    // { l1 -> I' }
+                    constructor(persistentMapOf(NormalPath to map[label]!!))
+                }
             } else {
                 /* This means no info for the specific label. */
                 empty()

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/FirHelpers.kt

@@ -127,7 +127,7 @@ fun ConeKotlinType.toRegularClass(session: FirSession): FirRegularClass? {
     return safeAs<ConeClassLikeType>()?.fullyExpandedType(session)?.toRegularClass(session)
 }
 
-fun ConeKotlinType.isInline(session: FirSession) : Boolean = toRegularClass(session)?.isInline == true
+fun ConeKotlinType.isInline(session: FirSession): Boolean = toRegularClass(session)?.isInline == true
 
 /**
  * Returns the FirRegularClass associated with this
@@ -143,7 +143,7 @@ fun FirTypeRef.toRegularClass(session: FirSession): FirRegularClass? {
 inline fun <reified T : Any> FirQualifiedAccessExpression.getDeclaration(): T? {
     return this.calleeReference.safeAs<FirResolvedNamedReference>()
         ?.resolvedSymbol
-        ?.fir.safeAs<T>()
+        ?.fir.safeAs()
 }
 
 /**
@@ -153,17 +153,6 @@ inline fun <reified T : Any> FirQualifiedAccessExpression.getDeclaration(): T? {
 fun FirSymbolOwner<*>.getContainingClass(context: CheckerContext): FirClassLikeDeclaration<*>? =
     this.safeAs<FirCallableMemberDeclaration<*>>()?.containingClass()?.toSymbol(context.session)?.fir
 
-/**
- * Returns the FirClassLikeDeclaration the type alias is pointing
- * to provided `this` is a FirTypeAlias. Returns this otherwise.
- */
-fun FirClassLikeDeclaration<*>.followAlias(session: FirSession): FirClassLikeDeclaration<*> {
-    return this.safeAs<FirTypeAlias>()
-        ?.expandedTypeRef
-        ?.firClassLike(session)
-        ?: return this
-}
-
 /**
  * Returns the FirClassLikeDeclaration that the
  * sequence of FirTypeAlias'es points to starting

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/context/CheckerContext.kt

@@ -11,6 +11,7 @@ import kotlinx.collections.immutable.persistentListOf
 import kotlinx.collections.immutable.persistentSetOf
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.fir.expressions.FirGetClassCall
 import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccess
 import org.jetbrains.kotlin.fir.resolve.ImplicitReceiverStack
 import org.jetbrains.kotlin.fir.resolve.PersistentImplicitReceiverStack
@@ -23,6 +24,7 @@ abstract class CheckerContext {
     abstract val implicitReceiverStack: ImplicitReceiverStack
     abstract val containingDeclarations: List<FirDeclaration>
     abstract val qualifiedAccesses: List<FirQualifiedAccess>
+    abstract val getClassCalls: List<FirGetClassCall>
     abstract val sessionHolder: SessionHolder
     abstract val returnTypeCalculator: ReturnTypeCalculator
     abstract val suppressedDiagnostics: Set<String>
@@ -57,6 +59,7 @@ class PersistentCheckerContext private constructor(
     override val implicitReceiverStack: PersistentImplicitReceiverStack,
     override val containingDeclarations: PersistentList<FirDeclaration>,
     override val qualifiedAccesses: PersistentList<FirQualifiedAccess>,
+    override val getClassCalls: PersistentList<FirGetClassCall>,
     override val sessionHolder: SessionHolder,
     override val returnTypeCalculator: ReturnTypeCalculator,
     override val suppressedDiagnostics: PersistentSet<String>,
@@ -68,6 +71,7 @@ class PersistentCheckerContext private constructor(
         PersistentImplicitReceiverStack(),
         persistentListOf(),
         persistentListOf(),
+        persistentListOf(),
         sessionHolder,
         returnTypeCalculator,
         persistentSetOf(),
@@ -81,6 +85,7 @@ class PersistentCheckerContext private constructor(
             implicitReceiverStack.add(name, value),
             containingDeclarations,
             qualifiedAccesses,
+            getClassCalls,
             sessionHolder,
             returnTypeCalculator,
             suppressedDiagnostics,
@@ -95,6 +100,7 @@ class PersistentCheckerContext private constructor(
             implicitReceiverStack,
             containingDeclarations.add(declaration),
             qualifiedAccesses,
+            getClassCalls,
             sessionHolder,
             returnTypeCalculator,
             suppressedDiagnostics,
@@ -109,6 +115,22 @@ class PersistentCheckerContext private constructor(
             implicitReceiverStack,
             containingDeclarations,
             qualifiedAccesses.add(qualifiedAccess),
+            getClassCalls,
+            sessionHolder,
+            returnTypeCalculator,
+            suppressedDiagnostics,
+            allInfosSuppressed,
+            allWarningsSuppressed,
+            allErrorsSuppressed
+        )
+    }
+
+    fun addGetClassCall(getClassCall: FirGetClassCall): PersistentCheckerContext {
+        return PersistentCheckerContext(
+            implicitReceiverStack,
+            containingDeclarations,
+            qualifiedAccesses,
+            getClassCalls.add(getClassCall),
             sessionHolder,
             returnTypeCalculator,
             suppressedDiagnostics,
@@ -129,6 +151,7 @@ class PersistentCheckerContext private constructor(
             implicitReceiverStack,
             containingDeclarations,
             qualifiedAccesses,
+            getClassCalls,
             sessionHolder,
             returnTypeCalculator,
             suppressedDiagnostics.addAll(diagnosticNames),

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstPropertyChecker.kt

@@ -13,10 +13,19 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.isConst
+import org.jetbrains.kotlin.lexer.KtTokens
 
 object FirConstPropertyChecker : FirPropertyChecker() {
     override fun check(declaration: FirProperty, context: CheckerContext, reporter: DiagnosticReporter) {
         if (!declaration.isConst) return
+
+        if (declaration.isVar) {
+            val constModifier = declaration.getModifier(KtTokens.CONST_KEYWORD)
+            constModifier?.let {
+                reporter.reportOn(it.source, FirErrors.WRONG_MODIFIER_TARGET, it.token, "vars", context)
+            }
+        }
+
         val classKind = (context.containingDeclarations.lastOrNull() as? FirRegularClass)?.classKind
         if (classKind != ClassKind.OBJECT && context.containingDeclarations.size > 1) {
             reporter.reportOn(declaration.source, FirErrors.CONST_VAL_NOT_TOP_LEVEL_OR_OBJECT, context)

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirConstructorAllowedChecker.kt

@@ -32,7 +32,7 @@ object FirConstructorAllowedChecker : FirConstructorChecker() {
                 reporter.reportOn(source, FirErrors.NON_PRIVATE_CONSTRUCTOR_IN_ENUM, context)
             }
             ClassKind.CLASS -> if (containingClass is FirRegularClass && containingClass.modality == Modality.SEALED) {
-                val modifierList = with(FirModifierList) { source.getModifierList() } ?: return
+                val modifierList = source.getModifierList() ?: return
                 val hasIllegalModifier = modifierList.modifiers.any {
                     it.token != KtTokens.PROTECTED_KEYWORD && it.token != KtTokens.PRIVATE_KEYWORD
                 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerUtils.kt

@@ -5,9 +5,11 @@
 
 package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
+import org.jetbrains.kotlin.fir.FirElement
 import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.analysis.checkers.modality
@@ -16,7 +18,11 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyAccessor
+import org.jetbrains.kotlin.fir.expressions.FirVariableAssignment
+import org.jetbrains.kotlin.fir.languageVersionSettings
+import org.jetbrains.kotlin.fir.references.FirBackingFieldReference
 import org.jetbrains.kotlin.fir.types.FirImplicitTypeRef
+import org.jetbrains.kotlin.fir.visitors.FirVisitorVoid
 import org.jetbrains.kotlin.lexer.KtTokens
 
 internal fun isInsideExpectClass(containingClass: FirRegularClass, context: CheckerContext): Boolean {
@@ -85,7 +91,7 @@ internal fun checkPropertyInitializer(
     context: CheckerContext
 ) {
     val inInterface = containingClass?.isInterface == true
-    val hasAbstractModifier = modifierList?.modifiers?.any { it.token == KtTokens.ABSTRACT_KEYWORD } == true
+    val hasAbstractModifier = KtTokens.ABSTRACT_KEYWORD in modifierList
     val isAbstract = property.isAbstract || hasAbstractModifier
     if (isAbstract) {
         if (property.initializer == null && property.delegate == null && property.returnTypeRef is FirImplicitTypeRef) {
@@ -168,8 +174,36 @@ internal fun checkPropertyAccessors(
     reporter: DiagnosticReporter,
     context: CheckerContext
 ) {
-    property.setter?.source?.let {
-        if (property.isVal) {
+    if (property.isVal) {
+        if (property.getter != null) {
+            var reassignment: FirBackingFieldReference? = null
+            // TODO: consider replacing this with normal VariableAssignmentChecker and reporting all 'field = ...' in getter (not just 1st)
+            // This way is a bit hacky and does not handle diagnostic suppression normally
+            val visitor = object : FirVisitorVoid() {
+                override fun visitElement(element: FirElement) {
+                    element.acceptChildren(this)
+                }
+
+                override fun visitVariableAssignment(variableAssignment: FirVariableAssignment) {
+                    // Report the first violation (to match FE 1.0 behavior)
+                    if (reassignment != null) return
+
+                    val backingFieldReference = variableAssignment.lValue as? FirBackingFieldReference
+                    if (backingFieldReference?.resolvedSymbol?.fir == property) {
+                        reassignment = backingFieldReference
+                    }
+                }
+            }
+            property.getter?.body?.accept(visitor, null)
+            reassignment?.source?.let {
+                if (context.session.languageVersionSettings.supportsFeature(LanguageFeature.RestrictionOfValReassignmentViaBackingField)) {
+                    reporter.reportOn(it, FirErrors.VAL_REASSIGNMENT_VIA_BACKING_FIELD_ERROR, property.symbol, context)
+                } else {
+                    reporter.reportOn(it, FirErrors.VAL_REASSIGNMENT_VIA_BACKING_FIELD, property.symbol, context)
+                }
+            }
+        }
+        property.setter?.source?.let {
             reporter.reportOn(it, FirErrors.VAL_WITH_SETTER, context)
         }
     }
@@ -184,6 +218,5 @@ internal val FirClass<*>.canHaveOpenMembers: Boolean get() = modality() != Modal
 internal fun FirRegularClass.isInlineOrValueClass(): Boolean {
     if (this.classKind != ClassKind.CLASS) return false
 
-    val modifierList = with(FirModifierList) { source.getModifierList() }
-    return isInline || modifierList?.modifiers?.any { it.token == KtTokens.VALUE_KEYWORD } == true
+    return isInline || hasModifier(KtTokens.VALUE_KEYWORD)
 }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirFunctionParameterChecker.kt

@@ -5,13 +5,17 @@
 
 package org.jetbrains.kotlin.fir.analysis.checkers.declaration
 
+import org.jetbrains.kotlin.fir.FirRealSourceElementKind
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
 import org.jetbrains.kotlin.fir.analysis.checkers.isInline
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
-import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOnWithSuppression
 import org.jetbrains.kotlin.fir.declarations.FirFunction
+import org.jetbrains.kotlin.fir.diagnostics.ConeSimpleDiagnostic
+import org.jetbrains.kotlin.fir.diagnostics.DiagnosticKind
 import org.jetbrains.kotlin.fir.typeContext
+import org.jetbrains.kotlin.fir.types.FirErrorTypeRef
 import org.jetbrains.kotlin.fir.types.arrayElementType
 import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.fir.types.isUnsignedTypeOrNullableUnsignedType
@@ -20,13 +24,32 @@ import org.jetbrains.kotlin.types.AbstractTypeChecker
 object FirFunctionParameterChecker : FirFunctionChecker() {
     override fun check(declaration: FirFunction<*>, context: CheckerContext, reporter: DiagnosticReporter) {
         checkVarargParameters(declaration, context, reporter)
+        checkParameterTypes(declaration, context, reporter)
+    }
+
+    private fun checkParameterTypes(declaration: FirFunction<*>, context: CheckerContext, reporter: DiagnosticReporter) {
+        for (valueParameter in declaration.valueParameters) {
+            val returnTypeRef = valueParameter.returnTypeRef
+            if (returnTypeRef !is FirErrorTypeRef) continue
+            // type problems on real source are already reported by ConeDiagnostic.toFirDiagnostics
+            if (returnTypeRef.source?.kind == FirRealSourceElementKind) continue
+
+            val diagnostic = returnTypeRef.diagnostic
+            if (diagnostic is ConeSimpleDiagnostic && diagnostic.kind == DiagnosticKind.ValueParameterWithNoTypeAnnotation) {
+                reporter.reportOnWithSuppression(
+                    valueParameter,
+                    FirErrors.VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION,
+                    context
+                )
+            }
+        }
     }
 
     private fun checkVarargParameters(function: FirFunction<*>, context: CheckerContext, reporter: DiagnosticReporter) {
         val varargParameters = function.valueParameters.filter { it.isVararg }
         if (varargParameters.size > 1) {
             for (parameter in varargParameters) {
-                reporter.reportOn(parameter.source ?: continue, FirErrors.MULTIPLE_VARARG_PARAMETERS, context)
+                reporter.reportOnWithSuppression(parameter, FirErrors.MULTIPLE_VARARG_PARAMETERS, context)
             }
         }
 
@@ -38,8 +61,8 @@ object FirFunctionParameterChecker : FirFunctionChecker() {
             // Note: comparing with FE1.0, we skip checking if the type is not primitive because primitive types are not inline. That
             // is any primitive values are already allowed by the inline check.
             ) {
-                reporter.reportOn(
-                    varargParameter.source ?: continue,
+                reporter.reportOnWithSuppression(
+                    varargParameter,
                     FirErrors.FORBIDDEN_VARARG_PARAMETER_TYPE,
                     varargParameterType,
                     context

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirInlineClassDeclarationChecker.kt

@@ -173,8 +173,7 @@ object FirInlineClassDeclarationChecker : FirRegularClassChecker() {
     private fun FirValueParameter.isNotFinalReadOnly(primaryConstructorProperty: FirProperty?): Boolean {
         if (primaryConstructorProperty == null) return true
 
-        val modifierList = with(FirModifierList) { source.getModifierList() }
-        val isOpen = modifierList?.modifiers?.any { it.token == KtTokens.OPEN_KEYWORD } == true
+        val isOpen = hasModifier(KtTokens.OPEN_KEYWORD)
 
         return isVararg || !primaryConstructorProperty.isVal || isOpen
     }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirKClassWithIncorrectTypeArgumentChecker.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeTypeParameterInQualifiedAccess
+import org.jetbrains.kotlin.fir.resolve.inference.inferenceComponents
+import org.jetbrains.kotlin.fir.resolve.inference.isKClassType
+import org.jetbrains.kotlin.fir.scopes.impl.toConeType
+import org.jetbrains.kotlin.fir.types.*
+
+// See FE1.0 [KClassWithIncorrectTypeArgumentChecker]
+object FirKClassWithIncorrectTypeArgumentChecker : FirFileChecker() {
+    override fun check(declaration: FirFile, context: CheckerContext, reporter: DiagnosticReporter) {
+        for (topLevelDeclaration in declaration.declarations) {
+            if (topLevelDeclaration is FirCallableMemberDeclaration<*>) {
+                checkTopLevelDeclaration(topLevelDeclaration, context, reporter)
+            }
+        }
+    }
+
+    // When a type parameter is used as a type argument for KClass, it shouldn't be nullable.
+    //  bad:  fun <T> test1() = T::class
+    //  okay: fun <T: Any> test2() = T::class
+    private fun checkTopLevelDeclaration(
+        declaration: FirCallableMemberDeclaration<*>,
+        context: CheckerContext,
+        reporter: DiagnosticReporter
+    ) {
+        val source = declaration.source ?: return
+        if (source.kind is FirFakeSourceElementKind) return
+
+        val returnType = declaration.returnTypeRef.coneType
+        if (!returnType.isKClassTypeWithErrorOrNullableArgument(context.session.inferenceComponents.ctx)) return
+
+        val typeArgument = (returnType.typeArguments[0] as ConeKotlinTypeProjection).type
+        typeArgument.typeParameterFromError?.let {
+            reporter.reportOn(source, FirErrors.KCLASS_WITH_NULLABLE_TYPE_PARAMETER_IN_SIGNATURE, it.symbol, context)
+        }
+    }
+
+    private fun ConeKotlinType.isKClassTypeWithErrorOrNullableArgument(context: ConeInferenceContext): Boolean {
+        if (!this.isKClassType()) return false
+        val argumentType = typeArguments.toList().singleOrNull()?.let {
+            when (it) {
+                is ConeStarProjection -> null
+                is ConeKotlinTypeProjection -> it.type
+            }
+        } ?: return false
+        with(context) {
+            argumentType.typeParameterFromError?.let { typeParameter ->
+                return typeParameter.toConeType().isNullableType()
+            }
+            return argumentType is ConeKotlinErrorType || argumentType.isNullableType()
+        }
+    }
+
+    private val ConeKotlinType.typeParameterFromError: FirTypeParameter?
+        get() = ((this as? ConeKotlinErrorType)?.diagnostic as? ConeTypeParameterInQualifiedAccess)?.symbol?.fir
+
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberFunctionsChecker.kt

@@ -34,8 +34,8 @@ object FirMemberFunctionsChecker : FirRegularClassChecker() {
         if (source.kind is FirFakeSourceElementKind) return
         // If multiple (potentially conflicting) modality modifiers are specified, not all modifiers are recorded at `status`.
         // So, our source of truth should be the full modifier list retrieved from the source.
-        val modifierList = with(FirModifierList) { source.getModifierList() }
-        val hasAbstractModifier = modifierList?.modifiers?.any { it.token == KtTokens.ABSTRACT_KEYWORD } == true
+        val modifierList = source.getModifierList()
+        val hasAbstractModifier = KtTokens.ABSTRACT_KEYWORD in modifierList
         val isAbstract = function.isAbstract || hasAbstractModifier
         if (isAbstract) {
             if (!containingDeclaration.canHaveAbstractDeclaration) {
@@ -49,7 +49,7 @@ object FirMemberFunctionsChecker : FirRegularClassChecker() {
             }
         }
         val isInsideExpectClass = isInsideExpectClass(containingDeclaration, context)
-        val hasOpenModifier = modifierList?.modifiers?.any { it.token == KtTokens.OPEN_KEYWORD } == true
+        val hasOpenModifier = KtTokens.OPEN_KEYWORD in modifierList
         if (!function.hasBody) {
             if (containingDeclaration.isInterface) {
                 if (Visibilities.isPrivate(function.visibility)) {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirMemberPropertiesChecker.kt

@@ -146,7 +146,7 @@ object FirMemberPropertiesChecker : FirRegularClassChecker() {
         if (source.kind is FirFakeSourceElementKind) return
         // If multiple (potentially conflicting) modality modifiers are specified, not all modifiers are recorded at `status`.
         // So, our source of truth should be the full modifier list retrieved from the source.
-        val modifierList = with(FirModifierList) { property.source.getModifierList() }
+        val modifierList = property.source.getModifierList()
 
         checkPropertyInitializer(
             containingDeclaration,
@@ -159,7 +159,7 @@ object FirMemberPropertiesChecker : FirRegularClassChecker() {
         checkPropertyAccessors(property, reporter, context)
         checkExpectDeclarationVisibilityAndBody(property, source, reporter, context)
 
-        val hasAbstractModifier = modifierList?.modifiers?.any { it.token == KtTokens.ABSTRACT_KEYWORD } == true
+        val hasAbstractModifier = KtTokens.ABSTRACT_KEYWORD in modifierList
         val isAbstract = property.isAbstract || hasAbstractModifier
         if (containingDeclaration.isInterface &&
             Visibilities.isPrivate(property.visibility) &&
@@ -203,7 +203,7 @@ object FirMemberPropertiesChecker : FirRegularClassChecker() {
             }
         }
 
-        val hasOpenModifier = modifierList?.modifiers?.any { it.token == KtTokens.OPEN_KEYWORD } == true
+        val hasOpenModifier = KtTokens.OPEN_KEYWORD in modifierList
         if (hasOpenModifier &&
             containingDeclaration.isInterface &&
             !hasAbstractModifier &&

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierChecker.kt

@@ -169,7 +169,7 @@ object FirModifierChecker : FirBasicDeclarationChecker() {
         if (!isDeclarationMappedToSourceCorrectly(declaration, source)) return
         if (context.containingDeclarations.last() is FirDefaultPropertyAccessor) return
 
-        val modifierList = with(FirModifierList) { source.getModifierList() }
+        val modifierList = source.getModifierList()
         modifierList?.let { checkModifiers(it, declaration, reporter, context) }
     }
 

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirModifierUtils.kt

@@ -12,6 +12,7 @@ import com.intellij.util.diff.FlyweightCapableTreeStructure
 import org.jetbrains.kotlin.KtNodeTypes
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.analysis.checkers.getChildren
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.KtModifierList
@@ -44,19 +45,9 @@ internal sealed class FirModifierList {
             }
     }
 
-    companion object {
-        fun FirSourceElement?.getModifierList(): FirModifierList? {
-            return when (this) {
-                null -> null
-                is FirPsiSourceElement<*> -> (psi as? KtModifierListOwner)?.modifierList?.let { FirPsiModifierList(it) }
-                is FirLightSourceElement -> {
-                    val modifierListNode = lighterASTNode.getChildren(treeStructure).find { it?.tokenType == KtNodeTypes.MODIFIER_LIST }
-                        ?: return null
-                    FirLightModifierList(modifierListNode, treeStructure)
-                }
-            }
-        }
-    }
+    operator fun get(token: KtModifierKeywordToken): FirModifier<*>? = modifiers.firstOrNull { it.token == token }
+
+    operator fun contains(token: KtModifierKeywordToken): Boolean = modifiers.any { it.token == token }
 }
 
 private val MODIFIER_KEYWORD_SET = TokenSet.orSet(KtTokens.SOFT_KEYWORDS, TokenSet.create(KtTokens.IN_KEYWORD, KtTokens.FUN_KEYWORD))
@@ -82,3 +73,21 @@ internal sealed class FirModifier<Node : Any>(val node: Node, val token: KtModif
 
     abstract val source: FirSourceElement
 }
+
+internal fun FirSourceElement?.getModifierList(): FirModifierList? {
+    return when (this) {
+        null -> null
+        is FirPsiSourceElement<*> -> (psi as? KtModifierListOwner)?.modifierList?.let { FirModifierList.FirPsiModifierList(it) }
+        is FirLightSourceElement -> {
+            val modifierListNode = lighterASTNode.getChildren(treeStructure).find { it?.tokenType == KtNodeTypes.MODIFIER_LIST }
+                ?: return null
+            FirModifierList.FirLightModifierList(modifierListNode, treeStructure)
+        }
+    }
+}
+
+internal operator fun FirModifierList?.contains(token: KtModifierKeywordToken): Boolean = this?.contains(token) == true
+
+internal fun FirDeclaration.getModifier(token: KtModifierKeywordToken): FirModifier<*>? = source.getModifierList()?.get(token)
+
+internal fun FirDeclaration.hasModifier(token: KtModifierKeywordToken): Boolean = token in source.getModifierList()

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirOpenMemberChecker.kt

@@ -10,7 +10,6 @@ import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
 import org.jetbrains.kotlin.fir.FirRealSourceElementKind
 import org.jetbrains.kotlin.fir.FirSourceElement
 import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
-import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirModifierList.Companion.getModifierList
 import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
 import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
@@ -29,7 +28,7 @@ object FirOpenMemberChecker : FirClassChecker() {
                 memberDeclaration is FirConstructor
             ) continue
             val source = memberDeclaration.source ?: continue
-            if (memberDeclaration.isOpen || (source.hasOpenModifierInSource && source.shouldReportOpenFromSource)) {
+            if (memberDeclaration.isOpen || memberDeclaration.hasModifier(KtTokens.OPEN_KEYWORD) && source.shouldReportOpenFromSource) {
                 if (declaration.classKind == ClassKind.OBJECT) {
                     reporter.reportOn(source, FirErrors.NON_FINAL_MEMBER_IN_OBJECT, context)
                 } else {
@@ -39,7 +38,6 @@ object FirOpenMemberChecker : FirClassChecker() {
         }
     }
 
-    private val FirSourceElement.hasOpenModifierInSource: Boolean get() = getModifierList()?.modifiers?.any { it.token == KtTokens.OPEN_KEYWORD } == true
     private val FirSourceElement.shouldReportOpenFromSource: Boolean
         get() = when (kind) {
             FirRealSourceElementKind,

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelFunctionsChecker.kt

@@ -28,8 +28,7 @@ object FirTopLevelFunctionsChecker : FirFileChecker() {
         if (source.kind is FirFakeSourceElementKind) return
         // If multiple (potentially conflicting) modality modifiers are specified, not all modifiers are recorded at `status`.
         // So, our source of truth should be the full modifier list retrieved from the source.
-        val modifierList = with(FirModifierList) { source.getModifierList() }
-        if (modifierList?.modifiers?.any { it.token == KtTokens.ABSTRACT_KEYWORD } == true) return
+        if (function.hasModifier(KtTokens.ABSTRACT_KEYWORD)) return
         if (function.isExternal) return
         if (!function.hasBody && !function.isExpect) {
             reporter.reportOn(source, FirErrors.NON_MEMBER_FUNCTION_NO_BODY, function, context)

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirTopLevelPropertiesChecker.kt

@@ -26,7 +26,7 @@ object FirTopLevelPropertiesChecker : FirFileChecker() {
         if (source.kind is FirFakeSourceElementKind) return
         // If multiple (potentially conflicting) modality modifiers are specified, not all modifiers are recorded at `status`.
         // So, our source of truth should be the full modifier list retrieved from the source.
-        val modifierList = with(FirModifierList) { source.getModifierList() }
+        val modifierList = source.getModifierList()
 
         checkPropertyInitializer(
             containingClass = null,

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/jvm/FirJvmExternalDeclarationChecker.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.declaration.jvm
+
+import org.jetbrains.kotlin.fir.FirFakeSourceElementKind
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMemberDeclarationChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirModifierList
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.getModifier
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.getModifierList
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.lexer.KtTokens
+
+// TODO: Move this to different, JVM-specific module?
+object FirJvmExternalDeclarationChecker : FirMemberDeclarationChecker() {
+    override fun check(declaration: FirMemberDeclaration, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (!declaration.isExternal) return
+        val source = declaration.source ?: return
+        if (source.kind is FirFakeSourceElementKind) return
+
+        // WRONG_MODIFIER_TARGET on external constructor is intentionally NOT covered in this checker.
+        if (declaration !is FirFunction<*>) {
+            val target = when (declaration) {
+                is FirProperty -> "property"
+                is FirRegularClass -> "class"
+                else -> "non-function declaration"
+            }
+            val externalModifier = declaration.getModifier(KtTokens.EXTERNAL_KEYWORD)
+            externalModifier?.let {
+                reporter.reportOn(it.source, FirErrors.WRONG_MODIFIER_TARGET, it.token, target, context)
+            }
+        }
+
+        // TODO: Implement checkers for these JVM-specific errors (see ExternalFunChecker in FE1.0):
+        // - EXTERNAL_DECLARATION_IN_INTERFACE
+        // - EXTERNAL_DECLARATION_CANNOT_BE_ABSTRACT
+        // - EXTERNAL_DECLARATION_CANNOT_HAVE_BODY
+        // - EXTERNAL_DECLARATION_CANNOT_BE_INLINED
+    }
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirGetClassCallChecker.kt

@@ -13,9 +13,11 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
 import org.jetbrains.kotlin.fir.analysis.getChild
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameterRefsOwner
-import org.jetbrains.kotlin.fir.expressions.FirGetClassCall
-import org.jetbrains.kotlin.fir.expressions.FirResolvedQualifier
-import org.jetbrains.kotlin.fir.expressions.FirStatement
+import org.jetbrains.kotlin.fir.expressions.*
+import org.jetbrains.kotlin.fir.references.FirResolvedNamedReference
+import org.jetbrains.kotlin.fir.resolve.inference.inferenceComponents
+import org.jetbrains.kotlin.fir.scopes.impl.toConeType
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.lexer.KtTokens.QUEST
 
@@ -25,7 +27,6 @@ object FirGetClassCallChecker : FirBasicExpressionChecker() {
         val source = expression.source ?: return
         if (source.kind is FirFakeSourceElementKind) return
 
-        val argument = expression.argument as? FirResolvedQualifier ?: return
         // Note that raw FIR drops marked nullability "?" in, e.g., `A?::class`, `A<T?>::class`, or `A<T?>?::class`.
         // That is, AST structures for those expressions have token type QUEST, whereas FIR element doesn't have any information about it.
         //
@@ -36,10 +37,33 @@ object FirGetClassCallChecker : FirBasicExpressionChecker() {
         //
         // Only the 2nd example is valid, and we want to check if token type QUEST doesn't exist at the same level as COLONCOLON.
         val markedNullable = source.getChild(QUEST, depth = 1) != null
-        if (argument.isNullableLHSForCallableReference || markedNullable) {
-            reporter.reportOn(source, FirErrors.NULLABLE_TYPE_IN_CLASS_LITERAL_LHS, context)
+        val argument = expression.argument
+        val isNullable = markedNullable ||
+                (argument as? FirResolvedQualifier)?.isNullableLHSForCallableReference == true ||
+                argument.typeRef.coneType.isMarkedNullable ||
+                argument.typeRef.coneType.isNullableTypeParameter(context.session.inferenceComponents.ctx)
+        if (isNullable) {
+            if (argument.canBeDoubleColonLHSAsType) {
+                reporter.reportOn(source, FirErrors.NULLABLE_TYPE_IN_CLASS_LITERAL_LHS, context)
+            } else {
+                reporter.reportOn(
+                    argument.source,
+                    FirErrors.EXPRESSION_OF_NULLABLE_TYPE_IN_CLASS_LITERAL_LHS,
+                    argument.typeRef.coneType,
+                    context
+                )
+            }
             return
         }
+
+        argument.safeAsTypeParameterSymbol?.let {
+            if (!it.fir.isReified) {
+                // E.g., fun <T: Any> foo(): Any = T::class
+                reporter.reportOn(source, FirErrors.TYPE_PARAMETER_AS_REIFIED, it, context)
+            }
+        }
+
+        if (argument !is FirResolvedQualifier) return
         // TODO: differentiate RESERVED_SYNTAX_IN_CALLABLE_REFERENCE_LHS
         if (argument.typeArguments.isNotEmpty() && !argument.typeRef.coneType.isAllowedInClassLiteral(context)) {
             val typeParameters = (argument.symbol?.fir as? FirTypeParameterRefsOwner)?.typeParameters
@@ -53,6 +77,30 @@ object FirGetClassCallChecker : FirBasicExpressionChecker() {
         }
     }
 
+    private fun ConeKotlinType.isNullableTypeParameter(context: ConeInferenceContext): Boolean {
+        if (this !is ConeTypeParameterType) return false
+        val typeParameter = lookupTag.typeParameterSymbol.fir
+        with(context) {
+            return !typeParameter.isReified &&
+                    // E.g., fun <T> f2(t: T): Any = t::class
+                    typeParameter.toConeType().isNullableType()
+        }
+    }
+
+    private val FirExpression.canBeDoubleColonLHSAsType: Boolean
+        get() {
+            return this is FirResolvedQualifier ||
+                    this is FirResolvedReifiedParameterReference ||
+                    safeAsTypeParameterSymbol != null
+        }
+
+    private val FirExpression.safeAsTypeParameterSymbol: FirTypeParameterSymbol?
+        get() {
+            return ((this as? FirQualifiedAccessExpression)
+                ?.calleeReference as? FirResolvedNamedReference)
+                ?.resolvedSymbol as? FirTypeParameterSymbol
+        }
+
     private fun ConeKotlinType.isAllowedInClassLiteral(context: CheckerContext): Boolean =
         when (this) {
             is ConeClassLikeType -> {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirTypeParameterInQualifiedAccessChecker.kt

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.expression
+
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.analysis.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.expressions.FirCallableReferenceAccess
+import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
+import org.jetbrains.kotlin.fir.expressions.FirResolvedReifiedParameterReference
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeTypeParameterInQualifiedAccess
+import org.jetbrains.kotlin.fir.types.FirErrorTypeRef
+import org.jetbrains.kotlin.fir.types.FirTypeRef
+
+object FirTypeParameterInQualifiedAccessChecker : FirQualifiedAccessChecker() {
+    override fun check(expression: FirQualifiedAccessExpression, context: CheckerContext, reporter: DiagnosticReporter) {
+        checkExplicitReceiver(expression, context, reporter)
+        checkExpressionItself(expression, context, reporter)
+    }
+
+    private fun checkExpressionItself(
+        expression: FirQualifiedAccessExpression,
+        context: CheckerContext,
+        reporter: DiagnosticReporter
+    ) {
+        // Make sure the current qualified access is not part of another qualified access or class literals.
+        // E.g., for `T::toString`, which is a callable reference (a subtype of qualified access), type parameter T is checked once as an
+        // explicit receiver (or LHS). When we visit `T` (as a qualified access), we should not regard it as an expression here.
+        if (context.qualifiedAccesses.size > 1 || context.getClassCalls.isNotEmpty()) return
+
+        val diagnostic = expression.typeRef.coneTypeParameterInQualifiedAccess ?: return
+        val source = expression.source ?: return
+        reporter.reportOn(source, FirErrors.TYPE_PARAMETER_IS_NOT_AN_EXPRESSION, diagnostic.symbol, context)
+    }
+
+    private fun checkExplicitReceiver(
+        expression: FirQualifiedAccessExpression,
+        context: CheckerContext,
+        reporter: DiagnosticReporter
+    ) {
+        val explicitReceiver = expression.explicitReceiver
+        val typeParameterSymbol =
+            (explicitReceiver as? FirResolvedReifiedParameterReference)?.symbol
+                ?: explicitReceiver?.typeRef?.coneTypeParameterInQualifiedAccess?.symbol
+                ?: return
+        if (expression is FirCallableReferenceAccess) {
+            reporter.reportOn(expression.source, FirErrors.CALLABLE_REFERENCE_LHS_NOT_A_CLASS, context)
+        } else {
+            reporter.reportOn(explicitReceiver?.source, FirErrors.TYPE_PARAMETER_ON_LHS_OF_DOT, typeParameterSymbol, context)
+        }
+    }
+
+    private val FirTypeRef.coneTypeParameterInQualifiedAccess: ConeTypeParameterInQualifiedAccess?
+        get() = (this as? FirErrorTypeRef)?.diagnostic as? ConeTypeParameterInQualifiedAccess
+}

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/AbstractDiagnosticCollector.kt

@@ -214,6 +214,10 @@ abstract class AbstractDiagnosticCollector(
             visitWithQualifiedAccess(qualifiedAccessExpression)
         }
 
+        override fun visitGetClassCall(getClassCall: FirGetClassCall, data: Nothing?) {
+            visitWithGetClassCall(getClassCall)
+        }
+
         private inline fun visitWithDeclaration(
             declaration: FirDeclaration,
             block: () -> Unit = { declaration.acceptChildren(this, null) }
@@ -252,6 +256,17 @@ abstract class AbstractDiagnosticCollector(
                 context = existingContext
             }
         }
+
+        private fun visitWithGetClassCall(getClassCall: FirGetClassCall) {
+            val existingContext = context
+            context = context.addGetClassCall(getClassCall)
+            try {
+                getClassCall.runComponents()
+                getClassCall.acceptChildren(this, null)
+            } finally {
+                context = existingContext
+            }
+        }
     }
 
     protected open fun getDeclarationActionOnDeclarationEnter(declaration: FirDeclaration): DiagnosticCollectorDeclarationAction =

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/collectors/components/DeclarationCheckersDiagnosticComponent.kt

@@ -31,7 +31,7 @@ class DeclarationCheckersDiagnosticComponent(
     }
 
     override fun visitRegularClass(regularClass: FirRegularClass, data: CheckerContext) {
-        checkers.regularClassCheckers.check(regularClass, data, reporter)
+        (checkers.memberDeclarationCheckers + checkers.regularClassCheckers).check(regularClass, data, reporter)
     }
 
     override fun visitSimpleFunction(simpleFunction: FirSimpleFunction, data: CheckerContext) {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirDefaultErrorMessages.kt

@@ -39,6 +39,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ASSIGNED_VALUE_IS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.ASSIGN_OPERATOR_AMBIGUITY
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.BACKING_FIELD_IN_INTERFACE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.BREAK_OR_CONTINUE_OUTSIDE_A_LOOP
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CALLABLE_REFERENCE_LHS_NOT_A_CLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CANNOT_CHANGE_ACCESS_PRIVILEGE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CANNOT_WEAKEN_ACCESS_PRIVILEGE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CAN_BE_REPLACED_WITH_OPERATOR_ASSIGNMENT
@@ -54,10 +55,10 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONFLICTING_PROJE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONSTRUCTOR_IN_INTERFACE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONSTRUCTOR_IN_OBJECT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CYCLIC_CONSTRUCTOR_DELEGATION_CALL
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATED_PROPERTY_INSIDE_INLINE_CLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DATA_CLASS_NOT_PROPERTY_PARAMETER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DATA_CLASS_VARARG_PARAMETER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DATA_CLASS_WITHOUT_PARAMETERS
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATED_PROPERTY_INSIDE_INLINE_CLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATED_PROPERTY_IN_INTERFACE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATION_IN_INTERFACE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.DELEGATION_SUPER_CALL_IN_ENUM_CONSTRUCTOR
@@ -81,6 +82,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXPOSED_SUPER_CLA
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXPOSED_SUPER_INTERFACE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXPOSED_TYPEALIAS_EXPANDED_TYPE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXPOSED_TYPE_PARAMETER_BOUND
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXPRESSION_OF_NULLABLE_TYPE_IN_CLASS_LITERAL_LHS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXTENSION_PROPERTY_MUST_HAVE_ACCESSORS_OR_BE_ABSTRACT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.EXTENSION_PROPERTY_WITH_BACKING_FIELD
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.FORBIDDEN_VARARG_PARAMETER_TYPE
@@ -109,17 +111,18 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INSTANCE_ACCESS_B
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INTERFACE_WITH_SUPERCLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVALID_IF_AS_EXPRESSION
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.INVALID_TYPE_OF_ANNOTATION_MEMBER
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.KCLASS_WITH_NULLABLE_TYPE_PARAMETER_IN_SIGNATURE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LEAKED_IN_PLACE_LAMBDA
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_ANNOTATION_CLASS_ERROR
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_INTERFACE_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.LOCAL_OBJECT_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.MANY_COMPANION_OBJECTS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.MISSING_VAL_ON_ANNOTATION_PARAMETER
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NESTED_CLASS_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.MULTIPLE_VARARG_PARAMETERS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.MUST_BE_INITIALIZED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.MUST_BE_INITIALIZED_OR_BE_ABSTRACT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NAMED_ARGUMENTS_NOT_ALLOWED
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NESTED_CLASS_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NONE_APPLICABLE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NON_ABSTRACT_FUNCTION_WITH_NO_BODY
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NON_FINAL_MEMBER_IN_FINAL_CLASS
@@ -133,7 +136,6 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NOT_A_LOOP_LABEL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NOT_A_SUPERTYPE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NO_ELSE_IN_WHEN
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NO_THIS
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NO_TYPE_FOR_TYPE_PARAMETER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NULLABLE_TYPE_IN_CLASS_LITERAL_LHS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NULLABLE_TYPE_OF_ANNOTATION_MEMBER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.OTHER_ERROR
@@ -183,8 +185,11 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_ARGUMENTS_NO
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_MISMATCH
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETERS_IN_ENUM
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETERS_IN_OBJECT
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETER_AS_REIFIED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETER_AS_SUPERTYPE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETER_IN_CATCH_CLAUSE
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETER_IS_NOT_AN_EXPRESSION
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.TYPE_PARAMETER_ON_LHS_OF_DOT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNINITIALIZED_VARIABLE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNNECESSARY_LATEINIT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNRESOLVED_LABEL
@@ -196,9 +201,12 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNSAFE_OPERATOR_C
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UNUSED_VARIABLE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.UPPER_BOUND_VIOLATED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.USELESS_VARARG_ON_PARAMETER
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_REASSIGNMENT
-import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_WITH_SETTER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VALUE_CLASS_CANNOT_BE_CLONEABLE
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_REASSIGNMENT
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_REASSIGNMENT_VIA_BACKING_FIELD
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_REASSIGNMENT_VIA_BACKING_FIELD_ERROR
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAL_WITH_SETTER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARARG_OUTSIDE_PARENTHESES
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_EXPECTED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VARIABLE_INITIALIZER_IS_REDUNDANT
@@ -208,6 +216,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAR_ANNOTATION_PA
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAR_OVERRIDDEN_BY_VAL
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.VAR_TYPE_MISMATCH_ON_OVERRIDE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.WRONG_INVOCATION_KIND
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.WRONG_MODIFIER_TARGET
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.WRONG_NUMBER_OF_TYPE_ARGUMENTS
 
 @Suppress("unused")
@@ -348,6 +357,7 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             map.put(DEPRECATED_MODIFIER_PAIR, "Modifier ''{0}'' is deprecated in presence of ''{1}''", TO_STRING, TO_STRING)
             map.put(INCOMPATIBLE_MODIFIERS, "Modifier ''{0}'' is incompatible with ''{1}''", TO_STRING, TO_STRING)
             map.put(REDUNDANT_OPEN_IN_INTERFACE, "Modifier 'open' is redundant for abstract interface members")
+            map.put(WRONG_MODIFIER_TARGET, "Modifier ''{0}'' is not applicable to ''{1}''", TO_STRING, TO_STRING)
 
             // Applicability
             map.put(NONE_APPLICABLE, "None of the following functions are applicable: {0}", SYMBOLS)
@@ -373,7 +383,6 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
                 null,
                 TO_STRING
             )
-            map.put(NO_TYPE_FOR_TYPE_PARAMETER, "There're no types suitable for this type parameter") // &
             map.put(TYPE_PARAMETERS_IN_OBJECT, "Type parameters are not allowed for objects")
 //            map.put(ILLEGAL_PROJECTION_USAGE, ...) // &
             map.put(TYPE_PARAMETERS_IN_ENUM, "Enum class cannot have type parameters")
@@ -390,9 +399,25 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             map.put(REIFIED_TYPE_IN_CATCH_CLAUSE, "Reified type is forbidden for catch parameter")
             map.put(TYPE_PARAMETER_IN_CATCH_CLAUSE, "Type parameter is forbidden for catch parameter")
 
+            map.put(
+                KCLASS_WITH_NULLABLE_TYPE_PARAMETER_IN_SIGNATURE,
+                "Declaration has an inconsistent return type. " +
+                        "Please add upper bound Any for type parameter ''{0}'' or specify return type explicitly",
+                SYMBOL
+            )
+
+            map.put(TYPE_PARAMETER_AS_REIFIED, "Cannot use ''{0}'' as reified type parameter. Use a class instead", SYMBOL)
+
             // Reflection
+            map.put(CALLABLE_REFERENCE_LHS_NOT_A_CLASS, "Left-hand side of a callable reference cannot be a type parameter")
+
             map.put(CLASS_LITERAL_LHS_NOT_A_CLASS, "Only classes are allowed on the left hand side of a class literal")
             map.put(NULLABLE_TYPE_IN_CLASS_LITERAL_LHS, "Type in a class literal must not be nullable")
+            map.put(
+                EXPRESSION_OF_NULLABLE_TYPE_IN_CLASS_LITERAL_LHS,
+                "Expression in a class literal has a nullable type ''{0}'', use !! to make the type non-nullable",
+                RENDER_TYPE
+            )
 
             // Inline and value classes
             map.put(INLINE_CLASS_NOT_TOP_LEVEL, "Inline classes cannot be local or inner")
@@ -505,6 +530,7 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             map.put(USELESS_VARARG_ON_PARAMETER, "Vararg on this parameter is useless")
             map.put(MULTIPLE_VARARG_PARAMETERS, "Multiple vararg-parameters are prohibited")
             map.put(FORBIDDEN_VARARG_PARAMETER_TYPE, "Forbidden vararg parameter type: {0}", RENDER_TYPE)
+            map.put(VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION, "A type annotation is required on a value parameter")
 
             // Properties & accessors
             map.put(
@@ -570,6 +596,8 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             // Control flow diagnostics
             map.put(UNINITIALIZED_VARIABLE, "{0} must be initialized before access", PROPERTY_NAME)
             map.put(VAL_REASSIGNMENT, "Val cannot be reassigned", PROPERTY_NAME)
+            map.put(VAL_REASSIGNMENT_VIA_BACKING_FIELD, "Reassignment of read-only property via backing field is deprecated", PROPERTY_NAME)
+            map.put(VAL_REASSIGNMENT_VIA_BACKING_FIELD_ERROR, "Reassignment of read-only property via backing field", PROPERTY_NAME)
             map.put(
                 WRONG_INVOCATION_KIND,
                 "{2} wrong invocation kind: given {3} case, but {4} case is possible",
@@ -611,6 +639,14 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             map.put(NO_ELSE_IN_WHEN, "''when'' expression must be exhaustive, add necessary {0}", WHEN_MISSING_CASES)
             map.put(INVALID_IF_AS_EXPRESSION, "'if' must have both main and 'else' branches if used as an expression")
 
+            // Context tracking
+            map.put(TYPE_PARAMETER_IS_NOT_AN_EXPRESSION, "Type parameter ''{0}'' is not an expression", SYMBOL)
+            map.put(
+                TYPE_PARAMETER_ON_LHS_OF_DOT,
+                "Type parameter ''{0}'' cannot have or inherit a companion object, so it cannot be on the left hand side of dot",
+                SYMBOL
+            )
+
             // Function contracts
             map.put(ERROR_IN_CONTRACT_DESCRIPTION, "Error in contract description", TO_STRING)
 

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/FirDiagnosticRenderers.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassLikeSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.fir.types.render
 
@@ -27,6 +28,7 @@ object FirDiagnosticRenderers {
         when (symbol) {
             is FirClassLikeSymbol<*> -> symbol.classId.asString()
             is FirCallableSymbol<*> -> symbol.callableId.toString()
+            is FirTypeParameterSymbol -> symbol.name.asString()
             else -> "???"
         }
     }

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/diagnostics/coneDiagnosticToFirDiagnostic.kt

@@ -22,7 +22,6 @@ import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.resolve.calls.tower.isSuccess
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
-import org.jetbrains.kotlin.utils.ifEmpty
 
 private fun ConeDiagnostic.toFirDiagnostic(source: FirSourceElement): FirDiagnostic<FirSourceElement>? = when (this) {
     is ConeUnresolvedReferenceError -> FirErrors.UNRESOLVED_REFERENCE.on(source, this.name?.asString() ?: "<No name>")
@@ -51,6 +50,7 @@ private fun ConeDiagnostic.toFirDiagnostic(source: FirSourceElement): FirDiagnos
     is ConeIntermediateDiagnostic -> null
     is ConeContractDescriptionError -> FirErrors.ERROR_IN_CONTRACT_DESCRIPTION.on(source, this.reason)
     is ConeTypeParameterSupertype -> FirErrors.SUPERTYPE_NOT_A_CLASS_OR_INTERFACE.on(source, this.reason)
+    is ConeTypeParameterInQualifiedAccess -> null // reported in various checkers instead
     else -> throw IllegalArgumentException("Unsupported diagnostic type: ${this.javaClass}")
 }
 
@@ -146,7 +146,7 @@ private fun ConeSimpleDiagnostic.getFactory(): FirDiagnosticFactory0<FirSourceEl
         DiagnosticKind.JumpOutsideLoop -> FirErrors.BREAK_OR_CONTINUE_OUTSIDE_A_LOOP
         DiagnosticKind.NotLoopLabel -> FirErrors.NOT_A_LOOP_LABEL
         DiagnosticKind.VariableExpected -> FirErrors.VARIABLE_EXPECTED
-        DiagnosticKind.NoTypeForTypeParameter -> FirErrors.NO_TYPE_FOR_TYPE_PARAMETER
+        DiagnosticKind.ValueParameterWithNoTypeAnnotation -> FirErrors.VALUE_PARAMETER_WITH_NO_TYPE_ANNOTATION
         DiagnosticKind.UnknownCallableKind -> FirErrors.UNKNOWN_CALLABLE_KIND
         DiagnosticKind.IllegalProjectionUsage -> FirErrors.ILLEGAL_PROJECTION_USAGE
         DiagnosticKind.MissingStdlibClass -> FirErrors.MISSING_STDLIB_CLASS

compiler/fir/cones/src/org/jetbrains/kotlin/fir/types/ConeTypes.kt

@@ -40,6 +40,10 @@ object ConeStarProjection : ConeTypeProjection() {
         get() = ProjectionKind.STAR
 }
 
+sealed class ConeKotlinTypeProjection : ConeTypeProjection() {
+    abstract val type: ConeKotlinType
+}
+
 data class ConeKotlinTypeProjectionIn(override val type: ConeKotlinType) : ConeKotlinTypeProjection() {
     override val kind: ProjectionKind
         get() = ProjectionKind.IN
@@ -50,6 +54,16 @@ data class ConeKotlinTypeProjectionOut(override val type: ConeKotlinType) : Cone
         get() = ProjectionKind.OUT
 }
 
+val ConeTypeProjection.type: ConeKotlinType?
+    get() = when (this) {
+        ConeStarProjection -> null
+        is ConeKotlinTypeProjection -> type
+        is ConeKotlinType -> this
+    }
+
+val ConeTypeProjection.isStarProjection: Boolean
+    get() = this == ConeStarProjection
+
 // We assume type IS an invariant type projection to prevent additional wrapper here
 // (more exactly, invariant type projection contains type)
 sealed class ConeKotlinType : ConeKotlinTypeProjection(), KotlinTypeMarker, TypeArgumentListMarker {
@@ -68,17 +82,12 @@ sealed class ConeKotlinType : ConeKotlinTypeProjection(), KotlinTypeMarker, Type
     final override fun toString(): String {
         return render()
     }
-
     abstract override fun equals(other: Any?): Boolean
     abstract override fun hashCode(): Int
 }
 
 sealed class ConeSimpleKotlinType : ConeKotlinType(), SimpleTypeMarker
 
-sealed class ConeKotlinTypeProjection : ConeTypeProjection() {
-    abstract val type: ConeKotlinType
-}
-
 typealias ConeKotlinErrorType = ConeClassErrorType
 
 class ConeClassLikeErrorLookupTag(override val classId: ClassId) : ConeClassLikeLookupTag()
@@ -162,7 +171,8 @@ data class ConeCapturedType(
     val lowerType: ConeKotlinType?,
     override val nullability: ConeNullability = ConeNullability.NOT_NULL,
     val constructor: ConeCapturedTypeConstructor,
-    override val attributes: ConeAttributes = ConeAttributes.Empty
+    override val attributes: ConeAttributes = ConeAttributes.Empty,
+    val isProjectionNotNull: Boolean = false
 ) : ConeSimpleKotlinType(), CapturedTypeMarker {
     constructor(
         captureStatus: CaptureStatus, lowerType: ConeKotlinType?, projection: ConeTypeProjection,
@@ -315,6 +325,13 @@ open class ConeTypeVariable(name: String) : TypeVariableMarker {
 
 class ConeTypeVariableTypeConstructor(val debugName: String) : ConeClassifierLookupTag(), TypeVariableTypeConstructorMarker {
     override val name: Name get() = Name.identifier(debugName)
+
+    var isContainedInInvariantOrContravariantPositions: Boolean = false
+        private set
+
+    fun recordInfoAboutTypeVariableUsagesAsInvariantOrContravariantParameter() {
+        isContainedInInvariantOrContravariantPositions = true
+    }
 }
 
 abstract class ConeIntegerLiteralType(

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/CheckersContainers.kt

@@ -16,3 +16,8 @@ fun FirSessionFactory.FirSessionConfigurator.registerExtendedCommonCheckers() {
     useCheckers(ExtendedExpressionCheckers)
     useCheckers(ExtendedDeclarationCheckers)
 }
+
+// TODO: Move this to different, JVM-specific module?
+fun FirSessionFactory.FirSessionConfigurator.registerJvmCheckers() {
+    useCheckers(JvmDeclarationCheckers)
+}

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/CommonDeclarationCheckers.kt

@@ -70,6 +70,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
     )
 
     override val fileCheckers: Set<FirFileChecker> = setOf(
+        FirKClassWithIncorrectTypeArgumentChecker,
         FirTopLevelFunctionsChecker,
         FirTopLevelPropertiesChecker,
     )

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/CommonExpressionCheckers.kt

@@ -22,6 +22,7 @@ object CommonExpressionCheckers : ExpressionCheckers() {
         FirProjectionsOnNonClassTypeArgumentChecker,
         FirUpperBoundViolatedChecker,
         FirTypeArgumentsNotAllowedExpressionChecker,
+        FirTypeParameterInQualifiedAccessChecker,
         FirSealedClassConstructorCallChecker,
     )
     override val functionCallCheckers: Set<FirFunctionCallChecker> = setOf()

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/checkers/JvmDeclarationCheckers.kt

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.checkers
+
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.jvm.FirJvmExternalDeclarationChecker
+
+// TODO: Move this to different, JVM-specific module?
+object JvmDeclarationCheckers : DeclarationCheckers() {
+    override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker> = setOf(
+        FirJvmExternalDeclarationChecker,
+    )
+}

compiler/fir/entrypoint/src/org/jetbrains/kotlin/fir/session/FirSessionFactory.kt

@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.fir.analysis.extensions.additionalCheckers
 import org.jetbrains.kotlin.fir.caches.FirCachesFactory
 import org.jetbrains.kotlin.fir.caches.FirThreadUnsafeCachesFactory
 import org.jetbrains.kotlin.fir.checkers.registerCommonCheckers
+import org.jetbrains.kotlin.fir.checkers.registerJvmCheckers
 import org.jetbrains.kotlin.fir.extensions.BunchOfRegisteredExtensions
 import org.jetbrains.kotlin.fir.extensions.extensionService
 import org.jetbrains.kotlin.fir.extensions.registerExtensions
@@ -94,6 +95,7 @@ object FirSessionFactory {
 
             FirSessionConfigurator(this).apply {
                 registerCommonCheckers()
+                registerJvmCheckers()
                 init()
             }.configure()
 

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponents.kt

@@ -10,6 +10,7 @@ import org.jetbrains.kotlin.fir.backend.generators.AnnotationGenerator
 import org.jetbrains.kotlin.fir.backend.generators.CallAndReferenceGenerator
 import org.jetbrains.kotlin.fir.backend.generators.FakeOverrideGenerator
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
+import org.jetbrains.kotlin.ir.IrLock
 import org.jetbrains.kotlin.ir.declarations.IrFactory
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.util.SymbolTable
@@ -22,6 +23,7 @@ interface Fir2IrComponents {
     val irBuiltIns: IrBuiltIns
     val builtIns: Fir2IrBuiltIns
     val irFactory: IrFactory
+    val lock: IrLock
 
     val classifierStorage: Fir2IrClassifierStorage
     val declarationStorage: Fir2IrDeclarationStorage

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrComponentsStorage.kt

@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.fir.backend.generators.FakeOverrideGenerator
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.signaturer.FirBasedSignatureComposer
 import org.jetbrains.kotlin.fir.signaturer.FirMangler
+import org.jetbrains.kotlin.ir.IrLock
 import org.jetbrains.kotlin.ir.declarations.IrFactory
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.util.SymbolTable
@@ -36,4 +37,7 @@ class Fir2IrComponentsStorage(
     override lateinit var annotationGenerator: AnnotationGenerator
     override lateinit var callGenerator: CallAndReferenceGenerator
     override lateinit var fakeOverrideGenerator: FakeOverrideGenerator
+
+    override val lock: IrLock
+        get() = symbolTable.lock
 }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -866,8 +866,9 @@ class Fir2IrDeclarationStorage(
         irClass: IrClass,
         callableDeclaration: FirCallableDeclaration<*>
     ): FirCallableDeclaration<*>? {
-        // Init lazy class if necessary
-        irClass.declarations
+        if (irClass is Fir2IrLazyClass) {
+            irClass.getFakeOverridesByName(callableDeclaration.symbol.callableId.callableName)
+        }
         return fakeOverridesInClass[irClass]?.get(callableDeclaration)
     }
 
@@ -1144,40 +1145,42 @@ class Fir2IrDeclarationStorage(
         val fir = firSymbol.fir as F
         val irParent by lazy { findIrParent(fir) }
         val signature by lazy { signatureComposer.composeSignature(fir) }
-        getCachedIrDeclaration(fir) {
-            // Parent calculation provokes declaration calculation for some members from IrBuiltIns
-            @Suppress("UNUSED_EXPRESSION") irParent
-            signature
-        }?.let { return it.symbol }
-        val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
-        val declarationOrigin = computeDeclarationOrigin(firSymbol, parentOrigin)
-        // TODO: package fragment members (?)
-        when (val parent = irParent) {
-            is Fir2IrLazyClass -> {
-                assert(parentOrigin != IrDeclarationOrigin.DEFINED) {
-                    "Should not have reference to public API uncached property from source code"
+        synchronized(symbolTable.lock) {
+            getCachedIrDeclaration(fir) {
+                // Parent calculation provokes declaration calculation for some members from IrBuiltIns
+                @Suppress("UNUSED_EXPRESSION") irParent
+                signature
+            }?.let { return it.symbol }
+            val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
+            val declarationOrigin = computeDeclarationOrigin(firSymbol, parentOrigin)
+            // TODO: package fragment members (?)
+            when (val parent = irParent) {
+                is Fir2IrLazyClass -> {
+                    assert(parentOrigin != IrDeclarationOrigin.DEFINED) {
+                        "Should not have reference to public API uncached property from source code"
+                    }
+                    signature?.let {
+                        return createIrLazyDeclaration(it, parent, declarationOrigin).symbol
+                    }
                 }
-                signature?.let {
-                    return createIrLazyDeclaration(it, parent, declarationOrigin).symbol
-                }
-            }
-            is IrLazyClass -> {
-                val unwrapped = fir.unwrapFakeOverrides()
-                if (unwrapped !== fir) {
-                    when (unwrapped) {
-                        is FirSimpleFunction -> {
-                            return getIrFunctionSymbol(unwrapped.symbol)
-                        }
-                        is FirProperty -> {
-                            return getIrPropertySymbol(unwrapped.symbol)
+                is IrLazyClass -> {
+                    val unwrapped = fir.unwrapFakeOverrides()
+                    if (unwrapped !== fir) {
+                        when (unwrapped) {
+                            is FirSimpleFunction -> {
+                                return getIrFunctionSymbol(unwrapped.symbol)
+                            }
+                            is FirProperty -> {
+                                return getIrPropertySymbol(unwrapped.symbol)
+                            }
                         }
                     }
                 }
             }
+            return createIrDeclaration(irParent, declarationOrigin).apply {
+                (this as IrDeclaration).setAndModifyParent(irParent)
+            }.symbol
         }
-        return createIrDeclaration(irParent, declarationOrigin).apply {
-            (this as IrDeclaration).setAndModifyParent(irParent)
-        }.symbol
     }
 
     private fun computeDeclarationOrigin(
@@ -1223,7 +1226,9 @@ class Fir2IrDeclarationStorage(
 
     private fun getIrVariableSymbol(firVariable: FirVariable<*>): IrVariableSymbol {
         return localStorage.getVariable(firVariable)?.symbol
-            ?: throw IllegalArgumentException("Cannot find variable ${firVariable.render()} in local storage")
+            ?: run {
+                throw IllegalArgumentException("Cannot find variable ${firVariable.render()} in local storage")
+            }
     }
 
     fun getIrValueSymbol(firVariableSymbol: FirVariableSymbol<*>): IrSymbol {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DataClassMembersGenerator.kt

@@ -176,9 +176,7 @@ class DataClassMembersGenerator(val components: Fir2IrComponents) {
 
         fun generate(klass: FirClass<*>): List<FirDeclaration> {
             val propertyParametersCount = irClass.primaryConstructor?.explicitParameters?.size ?: 0
-            val properties = irClass.declarations
-                .filterIsInstance<IrProperty>()
-                .take(propertyParametersCount)
+            val properties = irClass.properties.filter { it.backingField != null }.take(propertyParametersCount).toList()
             if (properties.isEmpty()) {
                 return emptyList()
             }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/FakeOverrideGenerator.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.load.java.JavaDescriptorVisibilities
+import org.jetbrains.kotlin.name.Name
 
 class FakeOverrideGenerator(
     private val components: Fir2IrComponents,
@@ -70,60 +71,86 @@ class FakeOverrideGenerator(
         val useSiteMemberScope = klass.unsubstitutedScope(session, scopeSession, withForcedTypeCalculator = true)
         val superTypesCallableNames = useSiteMemberScope.getCallableNames()
         val realDeclarationSymbols = realDeclarations.filterIsInstance<FirSymbolOwner<*>>().mapTo(mutableSetOf(), FirSymbolOwner<*>::symbol)
-        val isLocal = klass !is FirRegularClass || klass.isLocal
-        for (name in superTypesCallableNames) {
-            useSiteMemberScope.processFunctionsByName(name) { functionSymbol ->
-                createFakeOverriddenIfNeeded(
-                    klass, this, isLocal, functionSymbol,
-                    declarationStorage::getCachedIrFunction,
-                    declarationStorage::createIrFunction,
-                    createFakeOverrideSymbol = { firFunction, callableSymbol ->
-                        FirFakeOverrideGenerator.createSubstitutionOverrideFunction(
-                            session, firFunction, callableSymbol,
-                            newDispatchReceiverType = klass.defaultType(),
-                            derivedClassId = klass.symbol.classId,
-                            isExpect = (klass as? FirRegularClass)?.isExpect == true
-                        )
-                    },
-                    baseFunctionSymbols,
-                    result,
-                    containsErrorTypes = { irFunction ->
-                        irFunction.returnType.containsErrorType() || irFunction.valueParameters.any { it.type.containsErrorType() }
-                    },
-                    realDeclarationSymbols,
-                    FirTypeScope::getDirectOverriddenFunctions,
-                    useSiteMemberScope,
-                )
-            }
 
-            useSiteMemberScope.processPropertiesByName(name) { propertySymbol ->
-                createFakeOverriddenIfNeeded(
-                    klass, this, isLocal, propertySymbol,
-                    declarationStorage::getCachedIrProperty,
-                    declarationStorage::createIrProperty,
-                    createFakeOverrideSymbol = { firProperty, callableSymbol ->
-                        FirFakeOverrideGenerator.createSubstitutionOverrideProperty(
-                            session, firProperty, callableSymbol,
-                            newDispatchReceiverType = klass.defaultType(),
-                            derivedClassId = klass.symbol.classId,
-                            isExpect = (klass as? FirRegularClass)?.isExpect == true
-                        )
-                    },
-                    basePropertySymbols,
-                    result,
-                    containsErrorTypes = { irProperty ->
-                        irProperty.backingField?.type?.containsErrorType() == true ||
-                                irProperty.getter?.returnType?.containsErrorType() == true
-                    },
-                    realDeclarationSymbols,
-                    FirTypeScope::getDirectOverriddenProperties,
-                    useSiteMemberScope,
-                )
-            }
+        for (name in superTypesCallableNames) {
+            generateFakeOverridesForName(this, useSiteMemberScope, name, klass, result, realDeclarationSymbols)
         }
         return result
     }
 
+    @OptIn(ExperimentalStdlibApi::class)
+    fun generateFakeOverridesForName(
+        irClass: IrClass,
+        name: Name,
+        firClass: FirClass<*>
+    ): List<IrDeclaration> = buildList {
+        val useSiteMemberScope = firClass.unsubstitutedScope(session, scopeSession, withForcedTypeCalculator = true)
+        generateFakeOverridesForName(
+            irClass, useSiteMemberScope, name, firClass, this,
+            // This parameter is only needed for data-class methods that is irrelevant for lazy library classes
+            realDeclarationSymbols = emptySet()
+        )
+    }
+
+    private fun generateFakeOverridesForName(
+        irClass: IrClass,
+        useSiteMemberScope: FirTypeScope,
+        name: Name,
+        firClass: FirClass<*>,
+        result: MutableList<IrDeclaration>,
+        realDeclarationSymbols: Set<AbstractFirBasedSymbol<*>>
+    ) {
+        val isLocal = firClass !is FirRegularClass || firClass.isLocal
+        useSiteMemberScope.processFunctionsByName(name) { functionSymbol ->
+            createFakeOverriddenIfNeeded(
+                firClass, irClass, isLocal, functionSymbol,
+                declarationStorage::getCachedIrFunction,
+                declarationStorage::createIrFunction,
+                createFakeOverrideSymbol = { firFunction, callableSymbol ->
+                    FirFakeOverrideGenerator.createSubstitutionOverrideFunction(
+                        session, firFunction, callableSymbol,
+                        newDispatchReceiverType = firClass.defaultType(),
+                        derivedClassId = firClass.symbol.classId,
+                        isExpect = (firClass as? FirRegularClass)?.isExpect == true
+                    )
+                },
+                baseFunctionSymbols,
+                result,
+                containsErrorTypes = { irFunction ->
+                    irFunction.returnType.containsErrorType() || irFunction.valueParameters.any { it.type.containsErrorType() }
+                },
+                realDeclarationSymbols,
+                FirTypeScope::getDirectOverriddenFunctions,
+                useSiteMemberScope,
+            )
+        }
+
+        useSiteMemberScope.processPropertiesByName(name) { propertySymbol ->
+            createFakeOverriddenIfNeeded(
+                firClass, irClass, isLocal, propertySymbol,
+                declarationStorage::getCachedIrProperty,
+                declarationStorage::createIrProperty,
+                createFakeOverrideSymbol = { firProperty, callableSymbol ->
+                    FirFakeOverrideGenerator.createSubstitutionOverrideProperty(
+                        session, firProperty, callableSymbol,
+                        newDispatchReceiverType = firClass.defaultType(),
+                        derivedClassId = firClass.symbol.classId,
+                        isExpect = (firClass as? FirRegularClass)?.isExpect == true
+                    )
+                },
+                basePropertySymbols,
+                result,
+                containsErrorTypes = { irProperty ->
+                    irProperty.backingField?.type?.containsErrorType() == true ||
+                            irProperty.getter?.returnType?.containsErrorType() == true
+                },
+                realDeclarationSymbols,
+                FirTypeScope::getDirectOverriddenProperties,
+                useSiteMemberScope,
+            )
+        }
+    }
+
     internal fun calcBaseSymbolsForFakeOverrideFunction(
         klass: FirClass<*>,
         fakeOverride: IrSimpleFunction,
@@ -158,10 +185,16 @@ class FakeOverrideGenerator(
         computeDirectOverridden: FirTypeScope.(S) -> List<S>,
         scope: FirTypeScope,
     ) {
-        if (originalSymbol !is S || originalSymbol in realDeclarationSymbols) return
+        if (originalSymbol !is S) return
         val classLookupTag = klass.symbol.toLookupTag()
         val originalDeclaration = originalSymbol.fir
+
         if (originalSymbol.dispatchReceiverClassOrNull() == classLookupTag && !originalDeclaration.origin.fromSupertypes) return
+        // Data classes' methods from Any (toString/equals/hashCode) are not handled by the line above because they have Any-typed dispatch receiver
+        // (there are no special FIR method for them, it's just fake overrides)
+        // But they are treated differently in IR (real declarations have already been declared before) and such methods are present among realDeclarationSymbols
+        if (originalSymbol in realDeclarationSymbols) return
+
         if (originalDeclaration.visibility == Visibilities.Private) return
 
         val origin = IrDeclarationOrigin.FAKE_OVERRIDE

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/AbstractFir2IrLazyDeclaration.kt

@@ -38,7 +38,7 @@ interface AbstractFir2IrLazyDeclaration<F : FirMemberDeclaration, D : IrDeclarat
         }
     }
 
-    fun createLazyAnnotations(): ReadWriteProperty<Any?, List<IrConstructorCall>> = lazyVar {
+    fun createLazyAnnotations(): ReadWriteProperty<Any?, List<IrConstructorCall>> = lazyVar(lock) {
         fir.annotations.mapNotNull {
             callGenerator.convertToIrConstructorCall(it) as? IrConstructorCall
         }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/AbstractFir2IrLazyFunction.kt

@@ -68,7 +68,7 @@ abstract class AbstractFir2IrLazyFunction<F : FirMemberDeclaration>(
         get() = null
         set(_) = error("We should never need to store body of external functions.")
 
-    override var visibility: DescriptorVisibility by lazyVar {
+    override var visibility: DescriptorVisibility by lazyVar(lock) {
         components.visibilityConverter.convertToDescriptorVisibility(fir.visibility)
     }
 

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyClass.kt

@@ -96,11 +96,11 @@ class Fir2IrLazyClass(
     override val isFun: Boolean
         get() = fir.isFun
 
-    override var superTypes: List<IrType> by lazyVar {
+    override var superTypes: List<IrType> by lazyVar(lock) {
         fir.superTypeRefs.map { it.toIrType(typeConverter) }
     }
 
-    override var thisReceiver: IrValueParameter? by lazyVar {
+    override var thisReceiver: IrValueParameter? by lazyVar(lock) {
         symbolTable.enterScope(this)
         val typeArguments = fir.typeParameters.map {
             IrSimpleTypeImpl(
@@ -117,7 +117,14 @@ class Fir2IrLazyClass(
         receiver
     }
 
-    override val declarations: MutableList<IrDeclaration> by lazyVar {
+    private val fakeOverridesByName = mutableMapOf<Name, Collection<IrDeclaration>>()
+
+    fun getFakeOverridesByName(name: Name): Collection<IrDeclaration> = fakeOverridesByName.getOrPut(name) {
+        fakeOverrideGenerator.generateFakeOverridesForName(this@Fir2IrLazyClass, name, fir)
+            .also(fakeOverrideGenerator::bindOverriddenSymbols)
+    }
+
+    override val declarations: MutableList<IrDeclaration> by lazyVar(lock) {
         val result = mutableListOf<IrDeclaration>()
         val processedNames = mutableSetOf<Name>()
         // NB: it's necessary to take all callables from scope,
@@ -166,11 +173,11 @@ class Fir2IrLazyClass(
                 else -> continue
             }
         }
-        with(fakeOverrideGenerator) {
-            val fakeOverrides = getFakeOverrides(fir, fir.declarations)
-            bindOverriddenSymbols(fakeOverrides)
-            result += fakeOverrides
+
+        for (name in scope.getCallableNames()) {
+            result += getFakeOverridesByName(name)
         }
+
         // TODO: remove this check to save time
         for (declaration in result) {
             if (declaration.parent != this) {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyConstructor.kt

@@ -67,11 +67,11 @@ class Fir2IrLazyConstructor(
             error("Mutating Fir2Ir lazy elements is not possible")
         }
 
-    override var returnType: IrType by lazyVar {
+    override var returnType: IrType by lazyVar(lock) {
         fir.returnTypeRef.toIrType(typeConverter)
     }
 
-    override var dispatchReceiverParameter: IrValueParameter? by lazyVar {
+    override var dispatchReceiverParameter: IrValueParameter? by lazyVar(lock) {
         val containingClass = parent as? IrClass
         val outerClass = containingClass?.parentClassOrNull
         if (containingClass?.isInner == true && outerClass != null) {
@@ -92,7 +92,7 @@ class Fir2IrLazyConstructor(
             error("Mutating Fir2Ir lazy elements is not possible")
         }
 
-    override var valueParameters: List<IrValueParameter> by lazyVar {
+    override var valueParameters: List<IrValueParameter> by lazyVar(lock) {
         declarationStorage.enterScope(this)
         fir.valueParameters.mapIndexed { index, valueParameter ->
             declarationStorage.createIrParameter(

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyProperty.kt

@@ -86,7 +86,7 @@ class Fir2IrLazyProperty(
     }
 
     @OptIn(ObsoleteDescriptorBasedAPI::class)
-    override var backingField: IrField? by lazyVar {
+    override var backingField: IrField? by lazyVar(lock) {
         // TODO: this checks are very preliminary, FIR resolve should determine backing field presence itself
         val parent = parent
         when {
@@ -126,7 +126,7 @@ class Fir2IrLazyProperty(
         }
     }
 
-    override var getter: IrSimpleFunction? by lazyVar {
+    override var getter: IrSimpleFunction? by lazyVar(lock) {
         if (fir.isConst) return@lazyVar null
         Fir2IrLazyPropertyAccessor(
             components, startOffset, endOffset,
@@ -155,7 +155,7 @@ class Fir2IrLazyProperty(
         }
     }
 
-    override var setter: IrSimpleFunction? by lazyVar {
+    override var setter: IrSimpleFunction? by lazyVar(lock) {
         if (!fir.isVar) null else Fir2IrLazyPropertyAccessor(
             components, startOffset, endOffset,
             when {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyPropertyAccessor.kt

@@ -45,11 +45,11 @@ class Fir2IrLazyPropertyAccessor(
     override val name: Name
         get() = Name.special("<${if (isSetter) "set" else "get"}-${firParentProperty.name}>")
 
-    override var returnType: IrType by lazyVar {
+    override var returnType: IrType by lazyVar(lock) {
         if (isSetter) irBuiltIns.unitType else firParentProperty.returnTypeRef.toIrType(typeConverter, conversionTypeContext)
     }
 
-    override var dispatchReceiverParameter: IrValueParameter? by lazyVar {
+    override var dispatchReceiverParameter: IrValueParameter? by lazyVar(lock) {
         val containingClass = parent as? IrClass
         if (containingClass != null && shouldHaveDispatchReceiver(containingClass, firParentProperty)
         ) {
@@ -57,13 +57,13 @@ class Fir2IrLazyPropertyAccessor(
         } else null
     }
 
-    override var extensionReceiverParameter: IrValueParameter? by lazyVar {
+    override var extensionReceiverParameter: IrValueParameter? by lazyVar(lock) {
         firParentProperty.receiverTypeRef?.let {
             createThisReceiverParameter(it.toIrType(typeConverter, conversionTypeContext))
         }
     }
 
-    override var valueParameters: List<IrValueParameter> by lazyVar {
+    override var valueParameters: List<IrValueParameter> by lazyVar(lock) {
         if (!isSetter) emptyList()
         else {
             declarationStorage.enterScope(this)
@@ -81,7 +81,7 @@ class Fir2IrLazyPropertyAccessor(
         }
     }
 
-    override var overriddenSymbols: List<IrSimpleFunctionSymbol> by lazyVar {
+    override var overriddenSymbols: List<IrSimpleFunctionSymbol> by lazyVar(lock) {
         firParentProperty.generateOverriddenAccessorSymbols(
             firParentClass,
             !isSetter,

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazySimpleFunction.kt

@@ -8,7 +8,6 @@ package org.jetbrains.kotlin.fir.lazy
 import org.jetbrains.kotlin.fir.backend.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.initialSignatureAttr
-import org.jetbrains.kotlin.fir.originalIfFakeOverride
 import org.jetbrains.kotlin.fir.symbols.Fir2IrSimpleFunctionSymbol
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.lazy.lazyVar
@@ -38,24 +37,24 @@ class Fir2IrLazySimpleFunction(
     override val name: Name
         get() = fir.name
 
-    override var returnType: IrType by lazyVar {
+    override var returnType: IrType by lazyVar(lock) {
         fir.returnTypeRef.toIrType(typeConverter)
     }
 
-    override var dispatchReceiverParameter: IrValueParameter? by lazyVar {
+    override var dispatchReceiverParameter: IrValueParameter? by lazyVar(lock) {
         val containingClass = parent as? IrClass
         if (containingClass != null && shouldHaveDispatchReceiver(containingClass, fir)) {
             createThisReceiverParameter(thisType = containingClass.thisReceiver?.type ?: error("No this receiver for containing class"))
         } else null
     }
 
-    override var extensionReceiverParameter: IrValueParameter? by lazyVar {
+    override var extensionReceiverParameter: IrValueParameter? by lazyVar(lock) {
         fir.receiverTypeRef?.let {
             createThisReceiverParameter(it.toIrType(typeConverter))
         }
     }
 
-    override var valueParameters: List<IrValueParameter> by lazyVar {
+    override var valueParameters: List<IrValueParameter> by lazyVar(lock) {
         declarationStorage.enterScope(this)
         fir.valueParameters.mapIndexed { index, valueParameter ->
             declarationStorage.createIrParameter(
@@ -68,11 +67,11 @@ class Fir2IrLazySimpleFunction(
         }
     }
 
-    override var overriddenSymbols: List<IrSimpleFunctionSymbol> by lazyVar {
+    override var overriddenSymbols: List<IrSimpleFunctionSymbol> by lazyVar(lock) {
         val parent = parent
         if (isFakeOverride && parent is Fir2IrLazyClass) {
             fakeOverrideGenerator.calcBaseSymbolsForFakeOverrideFunction(
-                firParent, this, fir.symbol.originalIfFakeOverride()!!
+                firParent, this, fir.symbol
             )
             fakeOverrideGenerator.getOverriddenSymbolsForFakeOverride(this)?.let { return@lazyVar it }
         }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt

@@ -61,7 +61,7 @@ class FirBasedSignatureComposer(private val mangler: FirMangler) : Fir2IrSignatu
         if (declaration is FirRegularClass && declaration.classId.isLocal) return null
         if (declaration is FirCallableMemberDeclaration<*>) {
             if (declaration.visibility == Visibilities.Local) return null
-            if (declaration.symbol.dispatchReceiverClassOrNull()?.classId?.isLocal == true || containingClass?.classId?.isLocal == true) return null
+            if (declaration.dispatchReceiverClassOrNull()?.classId?.isLocal == true || containingClass?.classId?.isLocal == true) return null
         }
         val builder = SignatureBuilder()
         try {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -2522,6 +2522,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
         @TestMetadata("compiler/testData/codegen/box/callableReference/adaptedReferences")
         @TestDataPath("$PROJECT_ROOT")
         public class AdaptedReferences {
+            @Test
+            @TestMetadata("adaptedVarargFunImportedFromObject.kt")
+            public void testAdaptedVarargFunImportedFromObject() throws Exception {
+                runTest("compiler/testData/codegen/box/callableReference/adaptedReferences/adaptedVarargFunImportedFromObject.kt");
+            }
+
             @Test
             public void testAllFilesPresentInAdaptedReferences() throws Exception {
                 KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/callableReference/adaptedReferences"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
@@ -5787,6 +5793,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/closures/capturedVarsOptimization/kt44347.kt");
             }
 
+            @Test
+            @TestMetadata("kt45446.kt")
+            public void testKt45446() throws Exception {
+                runTest("compiler/testData/codegen/box/closures/capturedVarsOptimization/kt45446.kt");
+            }
+
             @Test
             @TestMetadata("sharedSlotsWithCapturedVars.kt")
             public void testSharedSlotsWithCapturedVars() throws Exception {
@@ -12066,6 +12078,24 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/defaultArguments/inheritedFromInterfaceViaAbstractSuperclass.kt");
         }
 
+        @Test
+        @TestMetadata("kt36853.kt")
+        public void testKt36853() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36853.kt");
+        }
+
+        @Test
+        @TestMetadata("kt36853_nestedObject.kt")
+        public void testKt36853_nestedObject() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36853_nestedObject.kt");
+        }
+
+        @Test
+        @TestMetadata("kt36853a.kt")
+        public void testKt36853a() throws Exception {
+            runTest("compiler/testData/codegen/box/defaultArguments/kt36853a.kt");
+        }
+
         @Test
         @TestMetadata("kt36972_companion.kt")
         public void testKt36972_companion() throws Exception {
@@ -12720,6 +12750,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/delegatedProperty/insideInlinedObjectMultiModule.kt");
         }
 
+        @Test
+        @TestMetadata("javaDelegateTopLevel.kt")
+        public void testJavaDelegateTopLevel() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/javaDelegateTopLevel.kt");
+        }
+
         @Test
         @TestMetadata("kt35707.kt")
         public void testKt35707() throws Exception {
@@ -12738,6 +12774,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/delegatedProperty/kt4138.kt");
         }
 
+        @Test
+        @TestMetadata("kt45431.kt")
+        public void testKt45431() throws Exception {
+            runTest("compiler/testData/codegen/box/delegatedProperty/kt45431.kt");
+        }
+
         @Test
         @TestMetadata("kt6722.kt")
         public void testKt6722() throws Exception {
@@ -13246,6 +13288,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/delegation/inClassDeclaration.kt");
         }
 
+        @Test
+        @TestMetadata("inDataClass.kt")
+        public void testInDataClass() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/inDataClass.kt");
+        }
+
         @Test
         @TestMetadata("kt8154.kt")
         public void testKt8154() throws Exception {
@@ -14066,6 +14114,18 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/enum/kt38996.kt");
         }
 
+        @Test
+        @TestMetadata("kt44744.kt")
+        public void testKt44744() throws Exception {
+            runTest("compiler/testData/codegen/box/enum/kt44744.kt");
+        }
+
+        @Test
+        @TestMetadata("kt44744_innerClass.kt")
+        public void testKt44744_innerClass() throws Exception {
+            runTest("compiler/testData/codegen/box/enum/kt44744_innerClass.kt");
+        }
+
         @Test
         @TestMetadata("kt7257.kt")
         public void testKt7257() throws Exception {
@@ -15012,6 +15072,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/fir/Fir2IrClassifierStorage.kt");
         }
 
+        @Test
+        @TestMetadata("incorrectBytecodeWithEnhancedNullability.kt")
+        public void testIncorrectBytecodeWithEnhancedNullability() throws Exception {
+            runTest("compiler/testData/codegen/box/fir/incorrectBytecodeWithEnhancedNullability.kt");
+        }
+
         @Test
         @TestMetadata("IrBuiltIns.kt")
         public void testIrBuiltIns() throws Exception {
@@ -15582,6 +15648,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/functions/max.kt");
         }
 
+        @Test
+        @TestMetadata("mutualInline.kt")
+        public void testMutualInline() throws Exception {
+            runTest("compiler/testData/codegen/box/functions/mutualInline.kt");
+        }
+
         @Test
         @TestMetadata("nothisnoclosure.kt")
         public void testNothisnoclosure() throws Exception {
@@ -17710,6 +17782,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/inlineClasses/kt44141.kt");
         }
 
+        @Test
+        @TestMetadata("kt44867.kt")
+        public void testKt44867() throws Exception {
+            runTest("compiler/testData/codegen/box/inlineClasses/kt44867.kt");
+        }
+
         @Test
         @TestMetadata("mangledDefaultParameterFunction.kt")
         public void testMangledDefaultParameterFunction() throws Exception {
@@ -18654,6 +18732,24 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             public void testJavaSam() throws Exception {
                 runTest("compiler/testData/codegen/box/inlineClasses/funInterface/javaSam.kt");
             }
+
+            @Test
+            @TestMetadata("javaSamReturnResult.kt")
+            public void testJavaSamReturnResult() throws Exception {
+                runTest("compiler/testData/codegen/box/inlineClasses/funInterface/javaSamReturnResult.kt");
+            }
+
+            @Test
+            @TestMetadata("returnIC.kt")
+            public void testReturnIC() throws Exception {
+                runTest("compiler/testData/codegen/box/inlineClasses/funInterface/returnIC.kt");
+            }
+
+            @Test
+            @TestMetadata("returnResult.kt")
+            public void testReturnResult() throws Exception {
+                runTest("compiler/testData/codegen/box/inlineClasses/funInterface/returnResult.kt");
+            }
         }
 
         @Nested
@@ -19422,6 +19518,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/innerNested/createdNestedInOuterMember.kt");
         }
 
+        @Test
+        @TestMetadata("extenderNestedClass.kt")
+        public void testExtenderNestedClass() throws Exception {
+            runTest("compiler/testData/codegen/box/innerNested/extenderNestedClass.kt");
+        }
+
         @Test
         @TestMetadata("extensionFun.kt")
         public void testExtensionFun() throws Exception {
@@ -20402,6 +20504,18 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                     runTest("compiler/testData/codegen/box/invokedynamic/sam/functionRefToJavaInterface/intReturnTypeAsNumber.kt");
                 }
 
+                @Test
+                @TestMetadata("interfaceMemberRef.kt")
+                public void testInterfaceMemberRef() throws Exception {
+                    runTest("compiler/testData/codegen/box/invokedynamic/sam/functionRefToJavaInterface/interfaceMemberRef.kt");
+                }
+
+                @Test
+                @TestMetadata("kt45581.kt")
+                public void testKt45581() throws Exception {
+                    runTest("compiler/testData/codegen/box/invokedynamic/sam/functionRefToJavaInterface/kt45581.kt");
+                }
+
                 @Test
                 @TestMetadata("localFunction1.kt")
                 public void testLocalFunction1() throws Exception {
@@ -23326,6 +23440,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/jvmStatic/kt35716.kt");
         }
 
+        @Test
+        @TestMetadata("kt45408.kt")
+        public void testKt45408() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmStatic/kt45408.kt");
+        }
+
         @Test
         @TestMetadata("kt9897_static.kt")
         public void testKt9897_static() throws Exception {
@@ -36510,6 +36630,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/regressions/kt4281.kt");
         }
 
+        @Test
+        @TestMetadata("kt44993.kt")
+        public void testKt44993() throws Exception {
+            runTest("compiler/testData/codegen/box/regressions/kt44993.kt");
+        }
+
         @Test
         @TestMetadata("kt5056.kt")
         public void testKt5056() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/ir/Fir2IrTextTestGenerated.java

@@ -809,6 +809,12 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
                 runTest("compiler/testData/ir/irText/declarations/provideDelegate/differentReceivers.kt");
             }
 
+            @Test
+            @TestMetadata("javaDelegate.kt")
+            public void testJavaDelegate() throws Exception {
+                runTest("compiler/testData/ir/irText/declarations/provideDelegate/javaDelegate.kt");
+            }
+
             @Test
             @TestMetadata("local.kt")
             public void testLocal() throws Exception {
@@ -1358,6 +1364,12 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
             runTest("compiler/testData/ir/irText/expressions/kt42321.kt");
         }
 
+        @Test
+        @TestMetadata("kt44993.kt")
+        public void testKt44993() throws Exception {
+            runTest("compiler/testData/ir/irText/expressions/kt44993.kt");
+        }
+
         @Test
         @TestMetadata("kt45022.kt")
         public void testKt45022() throws Exception {
@@ -1829,6 +1841,12 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
                 runTest("compiler/testData/ir/irText/expressions/callableReferences/unboundMemberReferenceWithAdaptedArguments.kt");
             }
 
+            @Test
+            @TestMetadata("varargFunImportedFromObject.kt")
+            public void testVarargFunImportedFromObject() throws Exception {
+                runTest("compiler/testData/ir/irText/expressions/callableReferences/varargFunImportedFromObject.kt");
+            }
+
             @Test
             @TestMetadata("withAdaptationForSam.kt")
             public void testWithAdaptationForSam() throws Exception {
@@ -2098,6 +2116,12 @@ public class Fir2IrTextTestGenerated extends AbstractFir2IrTextTest {
             runTest("compiler/testData/ir/irText/firProblems/AnnotationLoader.kt");
         }
 
+        @Test
+        @TestMetadata("ArrayMap.kt")
+        public void testArrayMap() throws Exception {
+            runTest("compiler/testData/ir/irText/firProblems/ArrayMap.kt");
+        }
+
         @Test
         @TestMetadata("candidateSymbol.kt")
         public void testCandidateSymbol() throws Exception {

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaClass.kt

@@ -116,9 +116,6 @@ class FirJavaClass @FirImplementationDetail internal constructor(
         typeParameters.transformInplace(transformer, data)
         return this
     }
-
-    override fun replaceSource(newSource: FirSourceElement?) {
-    }
 }
 
 @FirBuilderDsl

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaConstructor.kt

@@ -138,9 +138,6 @@ class FirJavaConstructor @FirImplementationDetail constructor(
     override fun replaceBody(newBody: FirBlock?) {
         error("Body cannot be replaced for FirJavaConstructor")
     }
-
-    override fun replaceSource(newSource: FirSourceElement?) {
-    }
 }
 
 @FirBuilderDsl

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaField.kt

@@ -141,9 +141,6 @@ class FirJavaField @FirImplementationDetail constructor(
     override fun <D> transformDelegate(transformer: FirTransformer<D>, data: D): FirField {
         return this
     }
-
-    override fun replaceSource(newSource: FirSourceElement?) {
-    }
 }
 
 @FirBuilderDsl

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaMethod.kt

@@ -172,9 +172,6 @@ class FirJavaMethod @FirImplementationDetail constructor(
 
     override fun replaceContractDescription(newContractDescription: FirContractDescription) {
     }
-
-    override fun replaceSource(newSource: FirSourceElement?) {
-    }
 }
 
 val ALL_JAVA_OPERATION_NAMES =

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaValueParameter.kt

@@ -141,9 +141,6 @@ class FirJavaValueParameter @FirImplementationDetail constructor(
 
     override fun replaceControlFlowGraphReference(newControlFlowGraphReference: FirControlFlowGraphReference?) {
     }
-
-    override fun replaceSource(newSource: FirSourceElement?) {
-    }
 }
 
 @FirBuilderDsl

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/enhancement/javaTypeUtils.kt

@@ -219,7 +219,7 @@ private fun ConeKotlinType.getEnhancedNullability(
     if (!position.shouldEnhance()) return this.isMarkedNullable.noChange()
 
     return when (qualifiers.nullability) {
-        NullabilityQualifier.NULLABLE -> true.enhancedNullability()
+        NullabilityQualifier.NULLABLE -> true.noChange()
         NullabilityQualifier.NOT_NULL -> false.enhancedNullability()
         else -> this.isMarkedNullable.noChange()
     }

compiler/fir/jvm/src/org/jetbrains/kotlin/fir/types/jvm/FirJavaTypeRef.kt

@@ -54,8 +54,6 @@ class FirJavaTypeRef(
         return this
     }
 
-    override fun replaceSource(newSource: FirSourceElement?) {}
-
     override fun toString(): String {
         return type.render()
     }