[FIR] Add generator for checkers aliases and sets of checkers

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

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2010-2020 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.generator
+
+import kotlin.reflect.KClass
+import kotlin.reflect.full.superclasses
+
+class CheckersConfiguration(
+    val aliases: Map<KClass<*>, String>,
+    val additionalCheckers: MutableMap<String, String>
+) {
+    val parentsMap: Map<KClass<*>, List<KClass<*>>>
+
+    init {
+        val parents: MutableMap<KClass<*>, List<KClass<*>>> = mutableMapOf()
+        for (firKClass in aliases.keys) {
+            val directParents = mutableListOf<KClass<*>>()
+            bfs(
+                firKClass,
+                childrenExtractor = { it.superclasses }
+            ) {
+                if (it in aliases) {
+                    directParents += it
+                    false
+                } else {
+                    true
+                }
+            }
+            parents[firKClass] = directParents
+        }
+        parentsMap = parents
+    }
+}
+
+private fun <T> bfs(start: T, childrenExtractor: (T) -> Collection<T>, process: (T) -> Boolean) {
+    val queue = ArrayDeque<T>()
+    val visited = mutableSetOf<T>()
+    val levels = mutableMapOf(start to 0)
+    queue.addLast(start)
+    var levelToStop: Int? = null
+    while (queue.isNotEmpty()) {
+        val element = queue.removeFirst()
+        if (!visited.add(element)) continue
+        val level = levels.getValue(element)
+        if (levelToStop != null && level > levelToStop) continue
+        val shouldContinue = if (level > 0) process(element) else true
+        if (shouldContinue) {
+            val children = childrenExtractor(element)
+            for (child in children) {
+                levels[child] = level + 1
+                queue.addLast(child)
+            }
+        } else {
+            levelToStop = level
+        }
+    }
+}

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

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2010-2020 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.generator
+
+import org.jetbrains.kotlin.fir.FirElement
+import java.io.File
+import kotlin.reflect.KClass
+
+class CheckersConfigurator {
+    private val registeredAliases: MutableMap<KClass<*>, String> = LinkedHashMap()
+    private val additionalCheckers: MutableMap<String, String> = LinkedHashMap()
+
+    inline fun <reified T : FirElement> alias(name: String) {
+        alias(T::class, name)
+    }
+
+    fun alias(kClass: KClass<out FirElement>, name: String) {
+        val realName = name.takeIf { it.startsWith("Fir") } ?: "Fir$name"
+        registeredAliases[kClass] = realName
+    }
+
+    fun additional(fieldName: String, classFqn: String) {
+        additionalCheckers[fieldName] = classFqn
+    }
+
+    fun build(): CheckersConfiguration {
+        return CheckersConfiguration(registeredAliases, additionalCheckers)
+    }
+}
+
+fun generateCheckersComponents(
+    generationPath: File,
+    packageName: String,
+    abstractCheckerName: String,
+    init: CheckersConfigurator.() -> Unit
+) {
+    val configuration = CheckersConfigurator().apply(init).build()
+    Generator(configuration, generationPath, packageName, abstractCheckerName).generate()
+}

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

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2010-2020 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.generator
+
+import org.jetbrains.kotlin.fir.tree.generator.printer.*
+import java.io.File
+
+private typealias Alias = String
+private typealias Fqn = String
+
+private const val CHECKERS_COMPONENT_INTERNAL_ANNOTATION = "@CheckersComponentInternal"
+private const val CHECKERS_COMPONENT_INTERNAL_FQN = "org.jetbrains.kotlin.fir.analysis.CheckersComponentInternal"
+
+class Generator(
+    private val configuration: CheckersConfiguration,
+    generationPath: File,
+    private val packageName: String,
+    private val abstractCheckerName: String
+) {
+    private val generationPath: File
+
+    init {
+        var path = generationPath
+        packageName.split(".").forEach {
+            path = path.resolve(it)
+        }
+        path.mkdirs()
+        this.generationPath = path
+    }
+
+    private fun generateAliases() {
+        val filename = "${abstractCheckerName}Aliases.kt"
+        generationPath.resolve(filename).useSmartPrinter {
+            printPackageAndCopyright()
+            printGeneratedMessage()
+            configuration.aliases.keys
+                .mapNotNull { it.qualifiedName }
+                .sorted()
+                .forEach { println("import $it") }
+            println()
+            for ((kClass, alias) in configuration.aliases) {
+                println("typealias $alias = $abstractCheckerName<${kClass.simpleName}>")
+            }
+        }
+    }
+
+    private fun generateAbstractCheckersComponent() {
+        val filename = "${checkersComponentName}.kt"
+        generationPath.resolve(filename).useSmartPrinter {
+            printPackageAndCopyright()
+            printImports()
+            printGeneratedMessage()
+
+            println("abstract class $checkersComponentName {")
+            withIndent {
+                println("companion object {")
+                withIndent {
+                    println("val EMPTY: $checkersComponentName = object : $checkersComponentName() {}")
+                }
+                println("}")
+                println()
+
+                for (alias in configuration.aliases.values) {
+                    println("open ${alias.valDeclaration} = emptySet()")
+                }
+                println()
+
+                for ((fieldName, classFqn) in configuration.additionalCheckers) {
+                    val fieldClassName = classFqn.simpleName
+                    println("open val $fieldName: ${fieldClassName.setType} = emptySet()")
+                }
+                if (configuration.additionalCheckers.isNotEmpty()) {
+                    println()
+                }
+
+                for ((kClass, alias) in configuration.aliases) {
+                    print("$CHECKERS_COMPONENT_INTERNAL_ANNOTATION internal val ${alias.allFieldName}: ${alias.setType} get() = ${alias.fieldName}")
+                    for (parent in configuration.parentsMap.getValue(kClass)) {
+                        val parentAlias = configuration.aliases.getValue(parent)
+                        print(" + ${parentAlias.allFieldName}")
+                    }
+                    println()
+                }
+            }
+            println("}")
+        }
+    }
+
+    private fun generateComposedComponent() {
+        val composedComponentName = "Composed$checkersComponentName"
+        val filename = "${composedComponentName}.kt"
+        generationPath.resolve(filename).useSmartPrinter {
+            printPackageAndCopyright()
+            printImports()
+            printGeneratedMessage()
+            println("internal class $composedComponentName : $checkersComponentName() {")
+            withIndent {
+                // public overrides
+                for (alias in configuration.aliases.values) {
+                    println("override ${alias.valDeclaration}")
+                    withIndent {
+                        println("get() = _${alias.fieldName}")
+                    }
+                }
+                for ((fieldName, classFqn) in configuration.additionalCheckers) {
+                    println("override val $fieldName: ${classFqn.simpleName.setType}")
+                    withIndent {
+                        println("get() = _$fieldName")
+                    }
+                }
+                println()
+
+                // private mutable delegates
+                for (alias in configuration.aliases.values) {
+                    println("private val _${alias.fieldName}: ${alias.mutableSetType} = mutableSetOf()")
+                }
+                for ((fieldName, classFqn) in configuration.additionalCheckers) {
+                    println("private val _$fieldName: ${classFqn.simpleName.mutableSetType} = mutableSetOf()")
+                }
+                println()
+
+                // register function
+                println(CHECKERS_COMPONENT_INTERNAL_ANNOTATION)
+                println("internal fun register(checkers: $checkersComponentName) {")
+                withIndent {
+                    for (alias in configuration.aliases.values) {
+                        println("_${alias.fieldName} += checkers.${alias.allFieldName}")
+                    }
+                    for (fieldName in configuration.additionalCheckers.keys) {
+                        println("_$fieldName += checkers.$fieldName")
+                    }
+                }
+                println("}")
+            }
+            println("}")
+        }
+    }
+
+    private fun SmartPrinter.printPackageAndCopyright() {
+        printCopyright()
+        println("package $packageName")
+        println()
+    }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    private fun SmartPrinter.printImports() {
+        val imports = buildList {
+            addAll(configuration.additionalCheckers.values)
+            add(CHECKERS_COMPONENT_INTERNAL_FQN)
+        }.sorted()
+
+        for (fqn in imports) {
+            println("import $fqn")
+        }
+        println()
+    }
+
+    private val Alias.valDeclaration: String
+        get() = "val $fieldName: $setType"
+
+    private val Alias.fieldName: String
+        get() = removePrefix("Fir").decapitalize() + "s"
+
+    private val Alias.allFieldName: String
+        get() = "all${fieldName.capitalize()}"
+
+    private val Alias.setType: String
+        get() = "Set<$this>"
+
+    private val Alias.mutableSetType: String
+        get() = "MutableSet<$this>"
+
+    private val Fqn.simpleName: String
+        get() = this.split(".").last()
+
+    private val checkersComponentName = abstractCheckerName.removePrefix("Fir") + "s"
+
+    fun generate() {
+        generateAliases()
+        generateAbstractCheckersComponent()
+        generateComposedComponent()
+    }
+}

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

@@ -5,4 +5,49 @@
 
 package org.jetbrains.kotlin.fir.checkers.generator
 
-fun main() {}
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
+import org.jetbrains.kotlin.fir.expressions.FirStatement
+import org.jetbrains.kotlin.fir.expressions.FirVariableAssignment
+import java.io.File
+
+fun main(args: Array<String>) {
+    val generationPath = args.firstOrNull()?.let { File(it) } ?: File("compiler/fir/checkers/gen").absoluteFile
+
+    val expressionPackage = "org.jetbrains.kotlin.fir.analysis.checkers.expression"
+    generateCheckersComponents(generationPath, expressionPackage, "FirExpressionChecker") {
+        alias<FirStatement>("BasicExpressionChecker")
+        alias<FirQualifiedAccessExpression>("QualifiedAccessChecker")
+        alias<FirFunctionCall>("FunctionCallChecker")
+        alias<FirVariableAssignment>("VariableAssignmentChecker")
+    }
+
+    val declarationPackage = "org.jetbrains.kotlin.fir.analysis.checkers.declaration"
+    generateCheckersComponents(generationPath, declarationPackage, "FirDeclarationChecker") {
+        alias<FirDeclaration>("BasicDeclarationChecker")
+        alias<FirMemberDeclaration>("MemberDeclarationChecker")
+        alias<FirRegularClass>("RegularClassChecker")
+        alias<FirConstructor>("ConstructorChecker")
+        alias<FirFile>("FileChecker")
+
+        additional(
+            fieldName = "controlFlowAnalyserCheckers",
+            classFqn = "org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker"
+        )
+
+        additional(
+            fieldName = "variableAssignmentCfaBasedCheckers",
+            classFqn = "org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker"
+        )
+    }
+}
+
+/*
+ * Stages:
+ *   1. associate aliases with fir statements
+ *   2. build inheritance hierarchy for all mentioned fir elements
+ *   3. generate aliases
+ *   4. generate abstract "DeclarationCheckers"
+ *   5. generate "ComposedDeclarationCheckers" with OptIn annotation
+ */

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/declaration/ComposedDeclarationCheckers.kt

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2010-2020 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.analysis.CheckersComponentInternal
+import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+internal class ComposedDeclarationCheckers : DeclarationCheckers() {
+    override val basicDeclarationCheckers: Set<FirBasicDeclarationChecker>
+        get() = _basicDeclarationCheckers
+    override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker>
+        get() = _memberDeclarationCheckers
+    override val regularClassCheckers: Set<FirRegularClassChecker>
+        get() = _regularClassCheckers
+    override val constructorCheckers: Set<FirConstructorChecker>
+        get() = _constructorCheckers
+    override val fileCheckers: Set<FirFileChecker>
+        get() = _fileCheckers
+    override val controlFlowAnalyserCheckers: Set<FirControlFlowChecker>
+        get() = _controlFlowAnalyserCheckers
+    override val variableAssignmentCfaBasedCheckers: Set<AbstractFirPropertyInitializationChecker>
+        get() = _variableAssignmentCfaBasedCheckers
+
+    private val _basicDeclarationCheckers: MutableSet<FirBasicDeclarationChecker> = mutableSetOf()
+    private val _memberDeclarationCheckers: MutableSet<FirMemberDeclarationChecker> = mutableSetOf()
+    private val _regularClassCheckers: MutableSet<FirRegularClassChecker> = mutableSetOf()
+    private val _constructorCheckers: MutableSet<FirConstructorChecker> = mutableSetOf()
+    private val _fileCheckers: MutableSet<FirFileChecker> = mutableSetOf()
+    private val _controlFlowAnalyserCheckers: MutableSet<FirControlFlowChecker> = mutableSetOf()
+    private val _variableAssignmentCfaBasedCheckers: MutableSet<AbstractFirPropertyInitializationChecker> = mutableSetOf()
+
+    @CheckersComponentInternal
+    internal fun register(checkers: DeclarationCheckers) {
+        _basicDeclarationCheckers += checkers.allBasicDeclarationCheckers
+        _memberDeclarationCheckers += checkers.allMemberDeclarationCheckers
+        _regularClassCheckers += checkers.allRegularClassCheckers
+        _constructorCheckers += checkers.allConstructorCheckers
+        _fileCheckers += checkers.allFileCheckers
+        _controlFlowAnalyserCheckers += checkers.controlFlowAnalyserCheckers
+        _variableAssignmentCfaBasedCheckers += checkers.variableAssignmentCfaBasedCheckers
+    }
+}

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/declaration/DeclarationCheckers.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2020 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.analysis.CheckersComponentInternal
+import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+abstract class DeclarationCheckers {
+    companion object {
+        val EMPTY: DeclarationCheckers = object : DeclarationCheckers() {}
+    }
+
+    open val basicDeclarationCheckers: Set<FirBasicDeclarationChecker> = emptySet()
+    open val memberDeclarationCheckers: Set<FirMemberDeclarationChecker> = emptySet()
+    open val regularClassCheckers: Set<FirRegularClassChecker> = emptySet()
+    open val constructorCheckers: Set<FirConstructorChecker> = emptySet()
+    open val fileCheckers: Set<FirFileChecker> = emptySet()
+
+    open val controlFlowAnalyserCheckers: Set<FirControlFlowChecker> = emptySet()
+    open val variableAssignmentCfaBasedCheckers: Set<AbstractFirPropertyInitializationChecker> = emptySet()
+
+    @CheckersComponentInternal internal val allBasicDeclarationCheckers: Set<FirBasicDeclarationChecker> get() = basicDeclarationCheckers
+    @CheckersComponentInternal internal val allMemberDeclarationCheckers: Set<FirMemberDeclarationChecker> get() = memberDeclarationCheckers + allBasicDeclarationCheckers
+    @CheckersComponentInternal internal val allRegularClassCheckers: Set<FirRegularClassChecker> get() = regularClassCheckers + allMemberDeclarationCheckers
+    @CheckersComponentInternal internal val allConstructorCheckers: Set<FirConstructorChecker> get() = constructorCheckers + allMemberDeclarationCheckers
+    @CheckersComponentInternal internal val allFileCheckers: Set<FirFileChecker> get() = fileCheckers + allBasicDeclarationCheckers
+}

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDeclarationCheckerAliases.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2020 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
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+import org.jetbrains.kotlin.fir.declarations.FirConstructor
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirFile
+import org.jetbrains.kotlin.fir.declarations.FirMemberDeclaration
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+
+typealias FirBasicDeclarationChecker = FirDeclarationChecker<FirDeclaration>
+typealias FirMemberDeclarationChecker = FirDeclarationChecker<FirMemberDeclaration>
+typealias FirRegularClassChecker = FirDeclarationChecker<FirRegularClass>
+typealias FirConstructorChecker = FirDeclarationChecker<FirConstructor>
+typealias FirFileChecker = FirDeclarationChecker<FirFile>

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/expression/ComposedExpressionCheckers.kt

@@ -0,0 +1,37 @@
+/*
+ * Copyright 2010-2020 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.CheckersComponentInternal
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+internal class ComposedExpressionCheckers : ExpressionCheckers() {
+    override val basicExpressionCheckers: Set<FirBasicExpressionChecker>
+        get() = _basicExpressionCheckers
+    override val qualifiedAccessCheckers: Set<FirQualifiedAccessChecker>
+        get() = _qualifiedAccessCheckers
+    override val functionCallCheckers: Set<FirFunctionCallChecker>
+        get() = _functionCallCheckers
+    override val variableAssignmentCheckers: Set<FirVariableAssignmentChecker>
+        get() = _variableAssignmentCheckers
+
+    private val _basicExpressionCheckers: MutableSet<FirBasicExpressionChecker> = mutableSetOf()
+    private val _qualifiedAccessCheckers: MutableSet<FirQualifiedAccessChecker> = mutableSetOf()
+    private val _functionCallCheckers: MutableSet<FirFunctionCallChecker> = mutableSetOf()
+    private val _variableAssignmentCheckers: MutableSet<FirVariableAssignmentChecker> = mutableSetOf()
+
+    @CheckersComponentInternal
+    internal fun register(checkers: ExpressionCheckers) {
+        _basicExpressionCheckers += checkers.allBasicExpressionCheckers
+        _qualifiedAccessCheckers += checkers.allQualifiedAccessCheckers
+        _functionCallCheckers += checkers.allFunctionCallCheckers
+        _variableAssignmentCheckers += checkers.allVariableAssignmentCheckers
+    }
+}

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/expression/ExpressionCheckers.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2020 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.CheckersComponentInternal
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+abstract class ExpressionCheckers {
+    companion object {
+        val EMPTY: ExpressionCheckers = object : ExpressionCheckers() {}
+    }
+
+    open val basicExpressionCheckers: Set<FirBasicExpressionChecker> = emptySet()
+    open val qualifiedAccessCheckers: Set<FirQualifiedAccessChecker> = emptySet()
+    open val functionCallCheckers: Set<FirFunctionCallChecker> = emptySet()
+    open val variableAssignmentCheckers: Set<FirVariableAssignmentChecker> = emptySet()
+
+    @CheckersComponentInternal internal val allBasicExpressionCheckers: Set<FirBasicExpressionChecker> get() = basicExpressionCheckers
+    @CheckersComponentInternal internal val allQualifiedAccessCheckers: Set<FirQualifiedAccessChecker> get() = qualifiedAccessCheckers + allBasicExpressionCheckers
+    @CheckersComponentInternal internal val allFunctionCallCheckers: Set<FirFunctionCallChecker> get() = functionCallCheckers + allQualifiedAccessCheckers
+    @CheckersComponentInternal internal val allVariableAssignmentCheckers: Set<FirVariableAssignmentChecker> get() = variableAssignmentCheckers + allBasicExpressionCheckers
+}

compiler/fir/checkers/gen/org/jetbrains/kotlin/fir/analysis/checkers/expression/FirExpressionCheckerAliases.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2020 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
+
+/*
+ * This file was generated automatically
+ * DO NOT MODIFY IT MANUALLY
+ */
+
+import org.jetbrains.kotlin.fir.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
+import org.jetbrains.kotlin.fir.expressions.FirStatement
+import org.jetbrains.kotlin.fir.expressions.FirVariableAssignment
+
+typealias FirBasicExpressionChecker = FirExpressionChecker<FirStatement>
+typealias FirQualifiedAccessChecker = FirExpressionChecker<FirQualifiedAccessExpression>
+typealias FirFunctionCallChecker = FirExpressionChecker<FirFunctionCall>
+typealias FirVariableAssignmentChecker = FirExpressionChecker<FirVariableAssignment>

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

@@ -8,12 +8,13 @@ package org.jetbrains.kotlin.fir.analysis
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.FirSessionComponent
 import org.jetbrains.kotlin.fir.SessionConfiguration
-import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker
-import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.*
 import org.jetbrains.kotlin.fir.analysis.extensions.FirAdditionalCheckersExtension
 
+@RequiresOptIn
+annotation class CheckersComponentInternal
+
 class CheckersComponent : FirSessionComponent {
     val declarationCheckers: DeclarationCheckers get() = _declarationCheckers
     private val _declarationCheckers = ComposedDeclarationCheckers()
@@ -22,11 +23,13 @@ class CheckersComponent : FirSessionComponent {
     private val _expressionCheckers = ComposedExpressionCheckers()
 
     @SessionConfiguration
+    @OptIn(CheckersComponentInternal::class)
     fun register(checkers: DeclarationCheckers) {
         _declarationCheckers.register(checkers)
     }
 
     @SessionConfiguration
+    @OptIn(CheckersComponentInternal::class)
     fun register(checkers: ExpressionCheckers) {
         _expressionCheckers.register(checkers)
     }
@@ -39,61 +42,3 @@ class CheckersComponent : FirSessionComponent {
 }
 
 val FirSession.checkersComponent: CheckersComponent by FirSession.sessionComponentAccessor()
-
-private class ComposedDeclarationCheckers : DeclarationCheckers() {
-    override val fileCheckers: List<FirFileChecker>
-        get() = _fileCheckers
-    override val declarationCheckers: List<FirBasicDeclarationChecker>
-        get() = _declarationCheckers
-    override val memberDeclarationCheckers: List<FirMemberDeclarationChecker>
-        get() = _memberDeclarationCheckers
-    override val regularClassCheckers: List<FirRegularClassChecker>
-        get() = _regularClassCheckers
-    override val constructorCheckers: List<FirConstructorChecker>
-        get() = _constructorCheckers
-    override val controlFlowAnalyserCheckers: List<FirControlFlowChecker>
-        get() = _controlFlowAnalyserCheckers
-    override val variableAssignmentCfaBasedCheckers: List<AbstractFirPropertyInitializationChecker>
-        get() = _variableAssignmentCfaBasedCheckers
-
-    private val _fileCheckers: MutableList<FirFileChecker> = mutableListOf()
-    private val _declarationCheckers: MutableList<FirBasicDeclarationChecker> = mutableListOf()
-    private val _memberDeclarationCheckers: MutableList<FirMemberDeclarationChecker> = mutableListOf()
-    private val _regularClassCheckers: MutableList<FirRegularClassChecker> = mutableListOf()
-    private val _constructorCheckers: MutableList<FirConstructorChecker> = mutableListOf()
-    private val _controlFlowAnalyserCheckers: MutableList<FirControlFlowChecker> = mutableListOf()
-    private val _variableAssignmentCfaBasedCheckers: MutableList<AbstractFirPropertyInitializationChecker> = mutableListOf()
-
-    fun register(checkers: DeclarationCheckers) {
-        _fileCheckers += checkers.allFileCheckers
-        _declarationCheckers += checkers.declarationCheckers
-        _memberDeclarationCheckers += checkers.allMemberDeclarationCheckers
-        _regularClassCheckers += checkers.allRegularClassCheckers
-        _constructorCheckers += checkers.allConstructorCheckers
-        _controlFlowAnalyserCheckers += checkers.controlFlowAnalyserCheckers
-        _variableAssignmentCfaBasedCheckers += checkers.variableAssignmentCfaBasedCheckers
-    }
-}
-
-private class ComposedExpressionCheckers : ExpressionCheckers() {
-    override val expressionCheckers: List<FirBasicExpressionChecker>
-        get() = _expressionCheckers
-    override val qualifiedAccessCheckers: List<FirQualifiedAccessChecker>
-        get() = _qualifiedAccessCheckers
-    override val functionCallCheckers: List<FirFunctionCallChecker>
-        get() = _functionCallCheckers
-    override val variableAssignmentCheckers: List<FirVariableAssignmentChecker>
-        get() = _variableAssignmentCheckers
-
-    private val _expressionCheckers: MutableList<FirBasicExpressionChecker> = mutableListOf()
-    private val _qualifiedAccessCheckers: MutableList<FirQualifiedAccessChecker> = mutableListOf()
-    private val _functionCallCheckers: MutableList<FirFunctionCallChecker> = mutableListOf()
-    private val _variableAssignmentCheckers: MutableList<FirVariableAssignmentChecker> = mutableListOf()
-
-    fun register(checkers: ExpressionCheckers) {
-        _expressionCheckers += checkers.allExpressionCheckers
-        _qualifiedAccessCheckers += checkers.allQualifiedAccessCheckers
-        _functionCallCheckers += checkers.allFunctionCallCheckers
-        _variableAssignmentCheckers += checkers.variableAssignmentCheckers
-    }
-}

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

@@ -1,28 +0,0 @@
-/*
- * Copyright 2010-2020 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.analysis.cfa.AbstractFirPropertyInitializationChecker
-import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
-
-abstract class DeclarationCheckers {
-    companion object {
-        val EMPTY: DeclarationCheckers = object : DeclarationCheckers() {}
-    }
-
-    open val fileCheckers: List<FirFileChecker> = emptyList()
-    open val declarationCheckers: List<FirBasicDeclarationChecker> = emptyList()
-    open val memberDeclarationCheckers: List<FirMemberDeclarationChecker> = emptyList()
-    open val regularClassCheckers: List<FirRegularClassChecker> = emptyList()
-    open val constructorCheckers: List<FirConstructorChecker> = emptyList()
-    open val controlFlowAnalyserCheckers: List<FirControlFlowChecker> = emptyList()
-    open val variableAssignmentCfaBasedCheckers: List<AbstractFirPropertyInitializationChecker> = emptyList()
-
-    internal val allFileCheckers: List<FirFileChecker> get() = fileCheckers + declarationCheckers
-    internal val allMemberDeclarationCheckers: List<FirMemberDeclarationChecker> get() = memberDeclarationCheckers + declarationCheckers
-    internal val allRegularClassCheckers: List<FirRegularClassChecker> get() = regularClassCheckers + allMemberDeclarationCheckers
-    internal val allConstructorCheckers: List<FirConstructorChecker> get() = constructorCheckers + allMemberDeclarationCheckers
-}

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

@@ -12,9 +12,3 @@ import org.jetbrains.kotlin.fir.declarations.*
 abstract class FirDeclarationChecker<in D : FirDeclaration> {
     abstract fun check(declaration: D, context: CheckerContext, reporter: DiagnosticReporter)
 }
-
-typealias FirFileChecker = FirDeclarationChecker<FirFile>
-typealias FirBasicDeclarationChecker = FirDeclarationChecker<FirDeclaration>
-typealias FirMemberDeclarationChecker = FirDeclarationChecker<FirMemberDeclaration>
-typealias FirRegularClassChecker = FirDeclarationChecker<FirRegularClass>
-typealias FirConstructorChecker = FirDeclarationChecker<FirConstructor>

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

@@ -1,21 +0,0 @@
-/*
- * Copyright 2010-2020 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
-
-abstract class ExpressionCheckers {
-    companion object {
-        val EMPTY: ExpressionCheckers = object : ExpressionCheckers() {}
-    }
-
-    open val expressionCheckers: List<FirBasicExpressionChecker> = emptyList()
-    open val qualifiedAccessCheckers: List<FirQualifiedAccessChecker> = emptyList()
-    open val functionCallCheckers: List<FirFunctionCallChecker> = emptyList()
-    open val variableAssignmentCheckers: List<FirVariableAssignmentChecker> = emptyList()
-
-    internal val allExpressionCheckers get() = expressionCheckers
-    internal val allQualifiedAccessCheckers get() = qualifiedAccessCheckers + allExpressionCheckers
-    internal val allFunctionCallCheckers get() = functionCallCheckers + allQualifiedAccessCheckers
-}

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

@@ -7,16 +7,8 @@ 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.expressions.FirFunctionCall
-import org.jetbrains.kotlin.fir.expressions.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.expressions.FirStatement
-import org.jetbrains.kotlin.fir.expressions.FirVariableAssignment
 
 abstract class FirExpressionChecker<in E : FirStatement> {
     abstract fun check(expression: E, context: CheckerContext, reporter: DiagnosticReporter)
 }
-
-typealias FirBasicExpressionChecker = FirExpressionChecker<FirStatement>
-typealias FirQualifiedAccessChecker = FirExpressionChecker<FirQualifiedAccessExpression>
-typealias FirFunctionCallChecker = FirExpressionChecker<FirFunctionCall>
-typealias FirVariableAssignmentChecker = FirExpressionChecker<FirVariableAssignment>

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

@@ -42,34 +42,34 @@ class DeclarationCheckersDiagnosticComponent(
     }
 
     override fun visitAnonymousFunction(anonymousFunction: FirAnonymousFunction, data: CheckerContext) {
-        checkers.declarationCheckers.check(anonymousFunction, data, reporter)
+        checkers.basicDeclarationCheckers.check(anonymousFunction, data, reporter)
     }
 
     override fun visitPropertyAccessor(propertyAccessor: FirPropertyAccessor, data: CheckerContext) {
-        checkers.declarationCheckers.check(propertyAccessor, data, reporter)
+        checkers.basicDeclarationCheckers.check(propertyAccessor, data, reporter)
     }
 
     override fun visitValueParameter(valueParameter: FirValueParameter, data: CheckerContext) {
-        checkers.declarationCheckers.check(valueParameter, data, reporter)
+        checkers.basicDeclarationCheckers.check(valueParameter, data, reporter)
     }
 
     override fun visitTypeParameter(typeParameter: FirTypeParameter, data: CheckerContext) {
-        checkers.declarationCheckers.check(typeParameter, data, reporter)
+        checkers.basicDeclarationCheckers.check(typeParameter, data, reporter)
     }
 
     override fun visitEnumEntry(enumEntry: FirEnumEntry, data: CheckerContext) {
-        checkers.declarationCheckers.check(enumEntry, data, reporter)
+        checkers.basicDeclarationCheckers.check(enumEntry, data, reporter)
     }
 
     override fun visitAnonymousObject(anonymousObject: FirAnonymousObject, data: CheckerContext) {
-        checkers.declarationCheckers.check(anonymousObject, data, reporter)
+        checkers.basicDeclarationCheckers.check(anonymousObject, data, reporter)
     }
 
     override fun visitAnonymousInitializer(anonymousInitializer: FirAnonymousInitializer, data: CheckerContext) {
-        checkers.declarationCheckers.check(anonymousInitializer, data, reporter)
+        checkers.basicDeclarationCheckers.check(anonymousInitializer, data, reporter)
     }
 
-    private fun <D : FirDeclaration> List<FirDeclarationChecker<D>>.check(
+    private fun <D : FirDeclaration> Collection<FirDeclarationChecker<D>>.check(
         declaration: D,
         context: CheckerContext,
         reporter: DiagnosticReporter

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

@@ -16,15 +16,15 @@ class ExpressionCheckersDiagnosticComponent(collector: AbstractDiagnosticCollect
     private val checkers = session.checkersComponent.expressionCheckers
 
     override fun visitTypeOperatorCall(typeOperatorCall: FirTypeOperatorCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(typeOperatorCall, data, reporter)
+        checkers.basicExpressionCheckers.check(typeOperatorCall, data, reporter)
     }
 
     override fun <T> visitConstExpression(constExpression: FirConstExpression<T>, data: CheckerContext) {
-        checkers.expressionCheckers.check(constExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(constExpression, data, reporter)
     }
 
     override fun visitAnnotationCall(annotationCall: FirAnnotationCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(annotationCall, data, reporter)
+        checkers.basicExpressionCheckers.check(annotationCall, data, reporter)
     }
 
     override fun visitQualifiedAccessExpression(qualifiedAccessExpression: FirQualifiedAccessExpression, data: CheckerContext) {
@@ -40,54 +40,58 @@ class ExpressionCheckersDiagnosticComponent(collector: AbstractDiagnosticCollect
     }
 
     override fun visitThisReceiverExpression(thisReceiverExpression: FirThisReceiverExpression, data: CheckerContext) {
-        checkers.expressionCheckers.check(thisReceiverExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(thisReceiverExpression, data, reporter)
     }
 
     override fun visitResolvedQualifier(resolvedQualifier: FirResolvedQualifier, data: CheckerContext) {
-        checkers.expressionCheckers.check(resolvedQualifier, data, reporter)
+        checkers.basicExpressionCheckers.check(resolvedQualifier, data, reporter)
     }
 
     override fun visitWhenExpression(whenExpression: FirWhenExpression, data: CheckerContext) {
-        checkers.expressionCheckers.check(whenExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(whenExpression, data, reporter)
     }
 
     override fun visitBinaryLogicExpression(binaryLogicExpression: FirBinaryLogicExpression, data: CheckerContext) {
-        checkers.expressionCheckers.check(binaryLogicExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(binaryLogicExpression, data, reporter)
     }
 
     override fun visitArrayOfCall(arrayOfCall: FirArrayOfCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(arrayOfCall, data, reporter)
+        checkers.basicExpressionCheckers.check(arrayOfCall, data, reporter)
     }
 
     override fun visitStringConcatenationCall(stringConcatenationCall: FirStringConcatenationCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(stringConcatenationCall, data, reporter)
+        checkers.basicExpressionCheckers.check(stringConcatenationCall, data, reporter)
     }
 
     override fun visitCheckNotNullCall(checkNotNullCall: FirCheckNotNullCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(checkNotNullCall, data, reporter)
+        checkers.basicExpressionCheckers.check(checkNotNullCall, data, reporter)
     }
 
     override fun visitTryExpression(tryExpression: FirTryExpression, data: CheckerContext) {
-        checkers.expressionCheckers.check(tryExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(tryExpression, data, reporter)
     }
 
     override fun visitClassReferenceExpression(classReferenceExpression: FirClassReferenceExpression, data: CheckerContext) {
-        checkers.expressionCheckers.check(classReferenceExpression, data, reporter)
+        checkers.basicExpressionCheckers.check(classReferenceExpression, data, reporter)
     }
 
     override fun visitGetClassCall(getClassCall: FirGetClassCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(getClassCall, data, reporter)
+        checkers.basicExpressionCheckers.check(getClassCall, data, reporter)
     }
 
     override fun visitEqualityOperatorCall(equalityOperatorCall: FirEqualityOperatorCall, data: CheckerContext) {
-        checkers.expressionCheckers.check(equalityOperatorCall, data, reporter)
+        checkers.basicExpressionCheckers.check(equalityOperatorCall, data, reporter)
     }
 
     override fun visitVariableAssignment(variableAssignment: FirVariableAssignment, data: CheckerContext) {
         checkers.variableAssignmentCheckers.check(variableAssignment, data, reporter)
     }
 
-    private fun <E : FirStatement> List<FirExpressionChecker<E>>.check(expression: E, context: CheckerContext, reporter: DiagnosticReporter) {
+    private fun <E : FirStatement> Collection<FirExpressionChecker<E>>.check(
+        expression: E,
+        context: CheckerContext,
+        reporter: DiagnosticReporter
+    ) {
         for (checker in this) {
             checker.check(expression, context, reporter)
         }

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

@@ -13,9 +13,7 @@ import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.*
 
 object CommonDeclarationCheckers : DeclarationCheckers() {
-    override val fileCheckers: List<FirFileChecker> = listOf()
+    override val basicDeclarationCheckers: Set<FirBasicDeclarationChecker> = setOf(
-
-    override val declarationCheckers: List<FirBasicDeclarationChecker> = listOf(
         FirAnnotationClassDeclarationChecker,
         FirModifierChecker,
         FirManyCompanionObjectsChecker,
@@ -26,7 +24,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
         FirConflictingProjectionChecker,
     )
 
-    override val memberDeclarationCheckers: List<FirMemberDeclarationChecker> = listOf(
+    override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker> = setOf(
         FirInfixFunctionDeclarationChecker,
         FirExposedVisibilityDeclarationChecker,
         FirCommonConstructorDelegationIssuesChecker,
@@ -42,20 +40,20 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
         FirInapplicableLateinitChecker,
     )
 
-    override val regularClassCheckers: List<FirRegularClassChecker> = listOf(
+    override val regularClassCheckers: Set<FirRegularClassChecker> = setOf(
         FirTypeMismatchOnOverrideChecker,
     )
 
-    override val constructorCheckers: List<FirConstructorChecker> = listOf(
+    override val constructorCheckers: Set<FirConstructorChecker> = setOf(
         FirConstructorAllowedChecker,
     )
 
-    override val controlFlowAnalyserCheckers: List<FirControlFlowChecker> = listOf(
+    override val controlFlowAnalyserCheckers: Set<FirControlFlowChecker> = setOf(
         FirCallsEffectAnalyzer,
-        FirReturnsImpliesAnalyzer
+        FirReturnsImpliesAnalyzer,
     )
 
-    override val variableAssignmentCfaBasedCheckers: List<AbstractFirPropertyInitializationChecker> = listOf(
+    override val variableAssignmentCfaBasedCheckers: Set<AbstractFirPropertyInitializationChecker> = setOf(
-        FirPropertyInitializationAnalyzer
+        FirPropertyInitializationAnalyzer,
     )
 }

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

@@ -9,8 +9,7 @@ import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirSealedClassCons
 import org.jetbrains.kotlin.fir.analysis.checkers.expression.*
 
 object CommonExpressionCheckers : ExpressionCheckers() {
-    override val expressionCheckers: List<FirBasicExpressionChecker> = listOf()
+    override val qualifiedAccessCheckers: Set<FirQualifiedAccessChecker> = setOf(
-    override val qualifiedAccessCheckers: List<FirQualifiedAccessChecker> = listOf(
         FirSuperNotAvailableChecker,
         FirNotASupertypeChecker,
         FirSuperclassNotAccessibleFromInterfaceChecker,
@@ -21,5 +20,5 @@ object CommonExpressionCheckers : ExpressionCheckers() {
         FirTypeArgumentsNotAllowedExpressionChecker,
         FirSealedClassConstructorCallChecker,
     )
-    override val functionCallCheckers: List<FirFunctionCallChecker> = listOf()
+    override val functionCallCheckers: Set<FirFunctionCallChecker> = setOf()
 }

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

@@ -8,25 +8,29 @@ package org.jetbrains.kotlin.fir.checkers
 import org.jetbrains.kotlin.fir.analysis.cfa.AbstractFirPropertyInitializationChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.cfa.FirControlFlowChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.declaration.DeclarationCheckers
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirBasicDeclarationChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirDeclarationChecker
+import org.jetbrains.kotlin.fir.analysis.checkers.declaration.FirMemberDeclarationChecker
 import org.jetbrains.kotlin.fir.analysis.checkers.extended.*
+import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 
 object ExtendedDeclarationCheckers : DeclarationCheckers() {
-    override val declarationCheckers = listOf(
+    override val basicDeclarationCheckers: Set<FirBasicDeclarationChecker> = setOf(
         RedundantVisibilityModifierChecker,
-        RedundantReturnUnitType
+        RedundantReturnUnitType,
     )
 
-    override val memberDeclarationCheckers = listOf(
+    override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker> = setOf(
         RedundantModalityModifierChecker,
         RedundantExplicitTypeChecker,
-        RedundantSetterParameterTypeChecker
+        RedundantSetterParameterTypeChecker,
     )
 
-    override val variableAssignmentCfaBasedCheckers: List<AbstractFirPropertyInitializationChecker> = listOf(
+    override val variableAssignmentCfaBasedCheckers: Set<AbstractFirPropertyInitializationChecker> = setOf(
         CanBeValChecker,
     )
 
-    override val controlFlowAnalyserCheckers: List<FirControlFlowChecker> = listOf(
+    override val controlFlowAnalyserCheckers: Set<FirControlFlowChecker> = setOf(
-        UnusedChecker
+        UnusedChecker,
     )
 }

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

@@ -12,18 +12,18 @@ import org.jetbrains.kotlin.fir.analysis.checkers.expression.FirVariableAssignme
 import org.jetbrains.kotlin.fir.analysis.checkers.extended.*
 
 object ExtendedExpressionCheckers : ExpressionCheckers() {
-    override val expressionCheckers: List<FirBasicExpressionChecker> = listOf(
+    override val basicExpressionCheckers: Set<FirBasicExpressionChecker> = setOf(
         ArrayEqualityCanBeReplacedWithEquals,
         RedundantSingleExpressionStringTemplateChecker,
-        EmptyRangeChecker
+        EmptyRangeChecker,
     )
 
-    override val variableAssignmentCheckers: List<FirVariableAssignmentChecker> = listOf(
+    override val variableAssignmentCheckers: Set<FirVariableAssignmentChecker> = setOf(
-        CanBeReplacedWithOperatorAssignmentChecker
+        CanBeReplacedWithOperatorAssignmentChecker,
     )
 
-    override val qualifiedAccessCheckers: List<FirQualifiedAccessChecker> = listOf(
+    override val qualifiedAccessCheckers: Set<FirQualifiedAccessChecker> = setOf(
         RedundantCallOfConversionMethod,
-        UselessCallOnNotNullChecker
+        UselessCallOnNotNullChecker,
     )
 }

plugins/fir/fir-plugin-prototype/src/org/jetbrains/kotlin/fir/plugin/AllOpenAdditionalCheckers.kt

@@ -17,6 +17,6 @@ class AllOpenAdditionalCheckers(session: FirSession) : FirAdditionalCheckersExte
         get() = AllOpenPluginKey
 
     override val declarationCheckers: DeclarationCheckers = object : DeclarationCheckers() {
-        override val memberDeclarationCheckers: List<FirMemberDeclarationChecker> = listOf(DummyNameChecker)
+        override val memberDeclarationCheckers: Set<FirMemberDeclarationChecker> = setOf(DummyNameChecker)
     }
-}
+}