FIR checker: introduce NO_(GET|SET)_METHOD

Besides introducing new diagnostics, this commit unifies source usages
for array accesses in PSI & LT.

compiler/fir/analysis-tests/testData/resolve/arrays/arraySetWithOperation.kt

@@ -32,5 +32,5 @@ fun test_3(a: A<D>) {
 }
 
 fun test_4(b: B) {
-    <!UNRESOLVED_REFERENCE!><!UNRESOLVED_REFERENCE!>b[0]<!> += B()<!> // unresolved
+    <!UNRESOLVED_REFERENCE!>b<!NO_GET_METHOD!>[0]<!> += B()<!> // unresolved
 }

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

@@ -49,6 +49,7 @@ enum class PositioningStrategy(private val strategy: String? = null) {
     PRIVATE_MODIFIER,
     COMPANION_OBJECT,
     CONST_MODIFIER,
+    ARRAY_ACCESS
 
     ;
 

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

@@ -515,6 +515,11 @@ object DIAGNOSTICS_LIST : DiagnosticList() {
         }
     }
 
+    val CONVENTIONS by object : DiagnosticGroup("Conventions") {
+        val NO_GET_METHOD by error<FirSourceElement, KtArrayAccessExpression>(PositioningStrategy.ARRAY_ACCESS)
+        val NO_SET_METHOD by error<FirSourceElement, KtArrayAccessExpression>(PositioningStrategy.ARRAY_ACCESS)
+    }
+
     val EXTENDED_CHECKERS by object : DiagnosticGroup("Extended checkers") {
         val REDUNDANT_VISIBILITY_MODIFIER by warning<FirSourceElement, KtModifierListOwner>(PositioningStrategy.VISIBILITY_MODIFIER)
         val REDUNDANT_MODALITY_MODIFIER by warning<FirSourceElement, KtModifierListOwner>(PositioningStrategy.MODALITY_MODIFIER)

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

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
 import org.jetbrains.kotlin.fir.types.ConeKotlinType
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.KtArrayAccessExpression
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtDestructuringDeclaration
@@ -307,6 +308,10 @@ object FirErrors {
     // Function contracts
     val ERROR_IN_CONTRACT_DESCRIPTION by error1<FirSourceElement, KtElement, String>(SourceElementPositioningStrategies.SELECTOR_BY_QUALIFIED)
 
+    // Conventions
+    val NO_GET_METHOD by error0<FirSourceElement, KtArrayAccessExpression>(SourceElementPositioningStrategies.ARRAY_ACCESS)
+    val NO_SET_METHOD by error0<FirSourceElement, KtArrayAccessExpression>(SourceElementPositioningStrategies.ARRAY_ACCESS)
+
     // Extended checkers
     val REDUNDANT_VISIBILITY_MODIFIER by warning0<FirSourceElement, KtModifierListOwner>(SourceElementPositioningStrategies.VISIBILITY_MODIFIER)
     val REDUNDANT_MODALITY_MODIFIER by warning0<FirSourceElement, KtModifierListOwner>(SourceElementPositioningStrategies.MODALITY_MODIFIER)

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

@@ -0,0 +1,30 @@
+/*
+ * 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.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.expressions.FirFunctionCall
+import org.jetbrains.kotlin.fir.references.FirErrorNamedReference
+import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeUnresolvedNameError
+import org.jetbrains.kotlin.util.OperatorNameConventions
+
+object FirConventionFunctionCallChecker : FirFunctionCallChecker() {
+    override fun check(expression: FirFunctionCall, context: CheckerContext, reporter: DiagnosticReporter) {
+        val calleeReference = expression.calleeReference as? FirErrorNamedReference ?: return
+        val diagnostic = calleeReference.diagnostic as? ConeUnresolvedNameError ?: return
+
+        if (expression.calleeReference.source?.kind == FirFakeSourceElementKind.ArrayAccessNameReference) {
+            when (diagnostic.name) {
+                OperatorNameConventions.GET -> reporter.reportOn(calleeReference.source, FirErrors.NO_GET_METHOD, context)
+                OperatorNameConventions.SET -> reporter.reportOn(calleeReference.source, FirErrors.NO_SET_METHOD, context)
+            }
+        }
+    }
+}

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

@@ -39,6 +39,10 @@ class ErrorNodeDiagnosticCollectorComponent(collector: AbstractDiagnosticCollect
             ?: errorNamedReference.source ?: return
         // Don't report duplicated unresolved reference on annotation entry (already reported on its type)
         if (source.elementType == KtNodeTypes.ANNOTATION_ENTRY && errorNamedReference.diagnostic is ConeUnresolvedNameError) return
+        // Already reported in FirConventionFunctionCallChecker
+        if (errorNamedReference.source?.kind == FirFakeSourceElementKind.ArrayAccessNameReference &&
+            errorNamedReference.diagnostic is ConeUnresolvedNameError
+        ) return
         reportFirDiagnostic(errorNamedReference.diagnostic, source, reporter, data)
     }
 

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

@@ -139,6 +139,8 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NOT_AN_ANNOTATION
 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_GET_METHOD
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NO_SET_METHOD
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.NO_THIS
 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
@@ -679,6 +681,10 @@ class FirDefaultErrorMessages : DefaultErrorMessages.Extension {
             // Function contracts
             map.put(ERROR_IN_CONTRACT_DESCRIPTION, "Error in contract description", TO_STRING)
 
+            // Conventions
+            map.put(NO_GET_METHOD, "No get method providing array access")
+            map.put(NO_SET_METHOD, "No set method providing array access")
+
             // Extended checkers group
             map.put(REDUNDANT_VISIBILITY_MODIFIER, "Redundant visibility modifier")
             map.put(REDUNDANT_MODALITY_MODIFIER, "Redundant modality modifier")

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

@@ -415,6 +415,17 @@ object LightTreePositioningStrategies {
             return markElement(tree.ifKeyword(node) ?: node, startOffset, endOffset, tree, node)
         }
     }
+
+    val ARRAY_ACCESS = object : LightTreePositioningStrategy() {
+        override fun mark(
+            node: LighterASTNode,
+            startOffset: Int,
+            endOffset: Int,
+            tree: FlyweightCapableTreeStructure<LighterASTNode>
+        ): List<TextRange> {
+            return markElement(tree.findChildByType(node, KtNodeTypes.INDICES)!!, startOffset, endOffset, tree, node)
+        }
+    }
 }
 
 fun FirSourceElement.hasValOrVar(): Boolean =

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

@@ -143,4 +143,8 @@ object SourceElementPositioningStrategies {
         PositioningStrategies.IF_EXPRESSION
     )
 
+    val ARRAY_ACCESS = SourceElementPositioningStrategy(
+        LightTreePositioningStrategies.ARRAY_ACCESS,
+        PositioningStrategies.ARRAY_ACCESS
+    )
 }

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

@@ -26,7 +26,9 @@ object CommonExpressionCheckers : ExpressionCheckers() {
         FirSealedClassConstructorCallChecker,
     )
 
-    override val functionCallCheckers: Set<FirFunctionCallChecker> = setOf()
+    override val functionCallCheckers: Set<FirFunctionCallChecker> = setOf(
+        FirConventionFunctionCallChecker,
+    )
 
     override val tryExpressionCheckers: Set<FirTryExpressionChecker> = setOf(
         FirCatchParameterChecker

compiler/fir/raw-fir/light-tree2fir/src/org/jetbrains/kotlin/fir/lightTree/converter/ExpressionsConverter.kt

@@ -825,10 +825,11 @@ class ExpressionsConverter(
         }
         val getArgument = context.arraySetArgument.remove(arrayAccess)
         return buildFunctionCall {
-            source = arrayAccess.toFirSourceElement()
+            val isGet = getArgument == null
+            source = (if (isGet) arrayAccess else arrayAccess.getParent()!!).toFirSourceElement()
             calleeReference = buildSimpleNamedReference {
-                source = this@buildFunctionCall.source
-                name = if (getArgument == null) OperatorNameConventions.GET else OperatorNameConventions.SET
+                source = arrayAccess.toFirSourceElement().fakeElement(FirFakeSourceElementKind.ArrayAccessNameReference)
+                name = if (isGet) OperatorNameConventions.GET else OperatorNameConventions.SET
             }
             explicitReceiver = firExpression
             argumentList = buildArgumentList {

compiler/fir/raw-fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -28,8 +28,6 @@ import org.jetbrains.kotlin.fir.expressions.builder.*
 import org.jetbrains.kotlin.fir.expressions.impl.FirSingleExpressionBlock
 import org.jetbrains.kotlin.fir.references.builder.*
 import org.jetbrains.kotlin.fir.scopes.FirScopeProvider
-import org.jetbrains.kotlin.name.CallableId
-import org.jetbrains.kotlin.name.LocalCallableIdConstructor
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.*
@@ -38,7 +36,9 @@ import org.jetbrains.kotlin.fir.types.impl.FirQualifierPartImpl
 import org.jetbrains.kotlin.fir.types.impl.FirTypeArgumentListImpl
 import org.jetbrains.kotlin.fir.types.impl.FirTypePlaceholderProjection
 import org.jetbrains.kotlin.lexer.KtTokens.*
+import org.jetbrains.kotlin.name.CallableId
 import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.LocalCallableIdConstructor
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.*
@@ -1931,23 +1931,14 @@ open class RawFirBuilder(
 
         override fun visitArrayAccessExpression(expression: KtArrayAccessExpression, data: Unit): FirElement {
             val arrayExpression = expression.arrayExpression
+            val getArgument = context.arraySetArgument.remove(expression)
             return buildFunctionCall {
-                val source: FirPsiSourceElement<*>
-                val getArgument = context.arraySetArgument.remove(expression)
-                if (getArgument != null) {
-                    calleeReference = buildSimpleNamedReference {
-                        source = expression.parent.toFirSourceElement()
-                        this.source = source.fakeElement(FirFakeSourceElementKind.ArrayAccessNameReference)
-                        name = OperatorNameConventions.SET
-                    }
-                } else {
-                    source = expression.toFirSourceElement()
-                    calleeReference = buildSimpleNamedReference {
-                        this.source = source.fakeElement(FirFakeSourceElementKind.ArrayAccessNameReference)
-                        name = OperatorNameConventions.GET
-                    }
+                val isGet = getArgument == null
+                source = (if (isGet) expression else expression.parent).toFirSourceElement()
+                calleeReference = buildSimpleNamedReference {
+                    source = expression.toFirSourceElement().fakeElement(FirFakeSourceElementKind.ArrayAccessNameReference)
+                    name = if (isGet) OperatorNameConventions.GET else OperatorNameConventions.SET
                 }
-                this.source = source
                 explicitReceiver = arrayExpression.toFirExpression("No array expression")
                 argumentList = buildArgumentList {
                     for (indexExpression in expression.indexExpressions) {

compiler/testData/diagnostics/tests/LValueAssignment.fir.kt

@@ -128,7 +128,7 @@ class Test() {
 
         (f@ a)[3] = 4
 
-        <!UNRESOLVED_REFERENCE!>this[54] = 34<!>
+        this<!NO_SET_METHOD!>[54]<!> = 34
     }
 }
 

compiler/testData/diagnostics/tests/annotations/rendering/memberProjectedOut.fir.kt

@@ -12,5 +12,5 @@ class C<T> {
 }
 
 fun test(a: C<out CharSequence>) {
-    <!INAPPLICABLE_CANDIDATE!>a[1] = 25<!>
+    <!INAPPLICABLE_CANDIDATE!>a[1]<!> = 25
 }

compiler/testData/diagnostics/tests/checkArguments/arrayAccessSet.fir.kt

@@ -31,5 +31,5 @@ fun test() {
     D[0] = ""
     D[0] = 2.72
 
-    <!INAPPLICABLE_CANDIDATE!>Z[0] = ""<!>
+    <!INAPPLICABLE_CANDIDATE!>Z[0]<!> = ""
 }

compiler/testData/diagnostics/tests/checkArguments/arrayAccessSetTooManyArgs.fir.kt

@@ -6,6 +6,6 @@ class A {
     operator fun set(x: String, value: Int) {}
 
     fun d(x: Int) {
-        <!INAPPLICABLE_CANDIDATE!>this["", 1] = 1<!>
+        <!INAPPLICABLE_CANDIDATE!>this["", 1]<!> = 1
     }
 }

compiler/testData/diagnostics/tests/collectionLiterals/noCollectionLiterals.fir.kt

@@ -1,7 +1,7 @@
 // !WITH_NEW_INFERENCE
 fun test(): Array<Int> {
     [1, 2]
-    <!UNRESOLVED_REFERENCE!>[1, 2][0]<!>
+    [1, 2]<!NO_GET_METHOD!>[0]<!>
     [1, 2].<!UNRESOLVED_REFERENCE!>get<!>(0)
 
     foo([""])

compiler/testData/diagnostics/tests/generics/projectionsScope/projectedOutConventions.fir.kt

@@ -9,6 +9,6 @@ class A<T> {
 
 fun test(a: A<out CharSequence>) {
     a <!INAPPLICABLE_CANDIDATE!>+<!> ""
-    <!INAPPLICABLE_CANDIDATE!>a[1] = ""<!>
+    <!INAPPLICABLE_CANDIDATE!>a[1]<!> = ""
     <!INAPPLICABLE_CANDIDATE!>a[""]<!>
 }

compiler/testData/diagnostics/tests/generics/projectionsScope/typeMismatchConventions.fir.kt

@@ -11,7 +11,7 @@ class Out<out F>
 
 fun test(a: A<out CharSequence>, y: Out<CharSequence>) {
     a <!INAPPLICABLE_CANDIDATE!>+<!> y
-    <!INAPPLICABLE_CANDIDATE!>a[1] = y<!>
+    <!INAPPLICABLE_CANDIDATE!>a[1]<!> = y
     <!INAPPLICABLE_CANDIDATE!>a[y]<!>
 
     a + Out<Nothing>()

compiler/testData/diagnostics/tests/incompleteCode/diagnosticWithSyntaxError/arrayExpression.fir.kt

@@ -4,5 +4,5 @@ package bar
 fun main() {
     class Some
 
-    Some[<!SYNTAX!><!>] <!UNRESOLVED_REFERENCE!>names<!> <!UNRESOLVED_REFERENCE!><!SYNTAX!>=<!> ["ads"]<!>
+    Some[<!SYNTAX!><!>] <!UNRESOLVED_REFERENCE!>names<!> <!SYNTAX!>=<!> <!NO_GET_METHOD!>["ads"]<!>
 }

compiler/testData/diagnostics/tests/incompleteCode/kt4866UnresolvedArrayAccess.fir.kt

@@ -1,5 +1,5 @@
 //KT-4866 Resolve does not work inside brackets with unresolved reference before
 
 fun test(i: Int, j: Int) {
-    <!UNRESOLVED_REFERENCE!><!UNRESOLVED_REFERENCE!>foo<!>[i, j]<!>
-}
+    <!UNRESOLVED_REFERENCE!>foo<!><!NO_GET_METHOD!>[i, j]<!>
+}

compiler/testData/diagnostics/tests/inference/kt28598.fir.kt

@@ -15,7 +15,7 @@ fun case_1(a: MutableList<out MutableList<MutableList<MutableList<MutableList<Mu
                         if (f != null) {
                             val g = f[0]
                             if (g != null) {
-                                val h = <!UNRESOLVED_REFERENCE!>g[0]<!>
+                                val h = g<!NO_GET_METHOD!>[0]<!>
                                 if (h != null) {
                                     h.<!UNRESOLVED_REFERENCE!>inc<!>()
                                 }
@@ -43,7 +43,7 @@ fun case_2(a: MutableList<out MutableList<MutableList<MutableList<out MutableLis
                         if (f != null) {
                             val g = f[0]
                             if (g != null) {
-                                val h = <!UNRESOLVED_REFERENCE!>g[0]<!> // no SMARTCAST diagnostic
+                                val h = g<!NO_GET_METHOD!>[0]<!> // no SMARTCAST diagnostic
                                 if (h != null) {
                                     h.<!UNRESOLVED_REFERENCE!>inc<!>()
                                 }

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/array.fir.kt

@@ -1,31 +0,0 @@
-// FILE: J.java
-
-import org.jetbrains.annotations.*;
-
-public class J {
-    @NotNull
-    public static Integer[] staticNN;
-    @Nullable
-    public static Integer[] staticN;
-    public static Integer[] staticJ;
-}
-
-// FILE: k.kt
-
-fun test() {
-    // @NotNull platform type
-    val platformNN = J.staticNN
-    // @Nullable platform type
-    val platformN = J.staticN
-    // platform type with no annotation
-    val platformJ = J.staticJ
-
-    platformNN[0]
-    <!UNSAFE_CALL!>platformN[0]<!>
-    platformJ[0]
-
-    platformNN[0] = 1
-    <!UNSAFE_CALL!>platformN[0]  = 1<!>
-    platformJ[0]  = 1
-}
-

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/array.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: J.java
 
 import org.jetbrains.annotations.*;

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/primitiveArray.fir.kt

@@ -1,31 +0,0 @@
-// FILE: J.java
-
-import org.jetbrains.annotations.*;
-
-public class J {
-    @NotNull
-    public static int[] staticNN;
-    @Nullable
-    public static int[] staticN;
-    public static int[] staticJ;
-}
-
-// FILE: k.kt
-
-fun test() {
-    // @NotNull platform type
-    val platformNN = J.staticNN
-    // @Nullable platform type
-    val platformN = J.staticN
-    // platform type with no annotation
-    val platformJ = J.staticJ
-
-    platformNN[0]
-    <!UNSAFE_CALL!>platformN[0]<!>
-    platformJ[0]
-
-    platformNN[0] = 1
-    <!UNSAFE_CALL!>platformN[0]  = 1<!>
-    platformJ[0]  = 1
-}
-

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/primitiveArray.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: J.java
 
 import org.jetbrains.annotations.*;

compiler/testData/diagnostics/tests/smartCasts/kt2865.fir.kt

@@ -7,6 +7,6 @@ fun foo(a: MutableMap<String, String>, x: String?) {
 }
 
 fun foo1(a: MutableMap<String, String>, x: String?) {
-    <!INAPPLICABLE_CANDIDATE!>a[x] = x!!<!>
+    <!INAPPLICABLE_CANDIDATE!>a[x]<!> = x!!
     a[x!!] = x
 }

compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/15.fir.kt

@@ -96,7 +96,7 @@ fun case_7() {
 fun case_8(y: MutableList<Boolean>) {
     var x: Boolean? = true
     if (x != null) {
-        <!INAPPLICABLE_CANDIDATE!>y[if (true) {x = null;0} else 0] = <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Boolean?")!>x<!><!>
+        <!INAPPLICABLE_CANDIDATE!>y[if (true) {x = null;0} else 0]<!> = <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Boolean?")!>x<!>
     }
 }
 
@@ -130,6 +130,6 @@ fun case_10() {
 fun case_11(y: MutableList<MutableList<Int>>) {
     var x: Int? = 10
     if (x != null) {
-        <!INAPPLICABLE_CANDIDATE!>y[if (true) {x = null;0} else 0][x] = 10<!>
+        <!INAPPLICABLE_CANDIDATE!>y[if (true) {x = null;0} else 0][x]<!> = 10
     }
 }

compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/28.fir.kt

@@ -6,6 +6,6 @@
 fun <T : List<T>> Inv<out T>.case_1() {
     if (this is MutableList<*>) {
         <!DEBUG_INFO_EXPRESSION_TYPE("Inv<out T> & kotlin.collections.MutableList<*> & Inv<out T>")!>this<!>
-        <!INAPPLICABLE_CANDIDATE!><!DEBUG_INFO_EXPRESSION_TYPE("Inv<out T> & kotlin.collections.MutableList<*> & Inv<out T>")!>this<!>[0] = <!DEBUG_INFO_EXPRESSION_TYPE("Inv<out T> & kotlin.collections.MutableList<*> & Inv<out T>")!>this<!>[1]<!>
+        <!INAPPLICABLE_CANDIDATE!><!DEBUG_INFO_EXPRESSION_TYPE("Inv<out T> & kotlin.collections.MutableList<*> & Inv<out T>")!>this<!>[0]<!> = <!DEBUG_INFO_EXPRESSION_TYPE("Inv<out T> & kotlin.collections.MutableList<*> & Inv<out T>")!>this<!>[1]
     }
 }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.psi
+import org.jetbrains.kotlin.psi.KtArrayAccessExpression
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtDestructuringDeclaration
@@ -1402,6 +1403,18 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.NO_GET_METHOD) { firDiagnostic ->
+        NoGetMethodImpl(
+            firDiagnostic as FirPsiDiagnostic<*>,
+            token,
+        )
+    }
+    add(FirErrors.NO_SET_METHOD) { firDiagnostic ->
+        NoSetMethodImpl(
+            firDiagnostic as FirPsiDiagnostic<*>,
+            token,
+        )
+    }
     add(FirErrors.REDUNDANT_VISIBILITY_MODIFIER) { firDiagnostic ->
         RedundantVisibilityModifierImpl(
             firDiagnostic as FirPsiDiagnostic<*>,

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.idea.frontend.api.symbols.KtVariableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.KtArrayAccessExpression
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtDestructuringDeclaration
@@ -987,6 +988,14 @@ sealed class KtFirDiagnostic<PSI: PsiElement> : KtDiagnosticWithPsi<PSI> {
         abstract val reason: String
     }
 
+    abstract class NoGetMethod : KtFirDiagnostic<KtArrayAccessExpression>() {
+        override val diagnosticClass get() = NoGetMethod::class
+    }
+
+    abstract class NoSetMethod : KtFirDiagnostic<KtArrayAccessExpression>() {
+        override val diagnosticClass get() = NoSetMethod::class
+    }
+
     abstract class RedundantVisibilityModifier : KtFirDiagnostic<KtModifierListOwner>() {
         override val diagnosticClass get() = RedundantVisibilityModifier::class
     }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -21,6 +21,7 @@ import org.jetbrains.kotlin.idea.frontend.api.symbols.KtVariableSymbol
 import org.jetbrains.kotlin.idea.frontend.api.types.KtType
 import org.jetbrains.kotlin.lexer.KtModifierKeywordToken
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.KtArrayAccessExpression
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.KtDeclaration
 import org.jetbrains.kotlin.psi.KtDestructuringDeclaration
@@ -1597,6 +1598,20 @@ internal class ErrorInContractDescriptionImpl(
     override val firDiagnostic: FirPsiDiagnostic<*> by weakRef(firDiagnostic)
 }
 
+internal class NoGetMethodImpl(
+    firDiagnostic: FirPsiDiagnostic<*>,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.NoGetMethod(), KtAbstractFirDiagnostic<KtArrayAccessExpression> {
+    override val firDiagnostic: FirPsiDiagnostic<*> by weakRef(firDiagnostic)
+}
+
+internal class NoSetMethodImpl(
+    firDiagnostic: FirPsiDiagnostic<*>,
+    override val token: ValidityToken,
+) : KtFirDiagnostic.NoSetMethod(), KtAbstractFirDiagnostic<KtArrayAccessExpression> {
+    override val firDiagnostic: FirPsiDiagnostic<*> by weakRef(firDiagnostic)
+}
+
 internal class RedundantVisibilityModifierImpl(
     firDiagnostic: FirPsiDiagnostic<*>,
     override val token: ValidityToken,