[FIR] KT-59421 add checker context receiver property backing field

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

@@ -2111,6 +2111,12 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.CONTEXT_RECEIVERS_WITH_BACKING_FIELD) { firDiagnostic ->
+        ContextReceiversWithBackingFieldImpl(
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.RECURSION_IN_IMPLICIT_TYPES) { firDiagnostic ->
         RecursionInImplicitTypesImpl(
             firDiagnostic as KtPsiDiagnostic,

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

@@ -1504,6 +1504,10 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         override val diagnosticClass get() = SubtypingBetweenContextReceivers::class
     }
 
+    interface ContextReceiversWithBackingField : KtFirDiagnostic<KtElement> {
+        override val diagnosticClass get() = ContextReceiversWithBackingField::class
+    }
+
     interface RecursionInImplicitTypes : KtFirDiagnostic<PsiElement> {
         override val diagnosticClass get() = RecursionInImplicitTypes::class
     }

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

@@ -1805,6 +1805,11 @@ internal class SubtypingBetweenContextReceiversImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<KtElement>(firDiagnostic, token), KtFirDiagnostic.SubtypingBetweenContextReceivers
 
+internal class ContextReceiversWithBackingFieldImpl(
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<KtElement>(firDiagnostic, token), KtFirDiagnostic.ContextReceiversWithBackingField
+
 internal class RecursionInImplicitTypesImpl(
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,

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

@@ -676,6 +676,7 @@ object DIAGNOSTICS_LIST : DiagnosticList("FirErrors") {
         val AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER by error<KtElement>(PositioningStrategy.REFERENCE_BY_QUALIFIED)
         val UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL by error<KtElement>(PositioningStrategy.NAME_IDENTIFIER)
         val SUBTYPING_BETWEEN_CONTEXT_RECEIVERS by error<KtElement>(PositioningStrategy.DEFAULT)
+        val CONTEXT_RECEIVERS_WITH_BACKING_FIELD by error<KtElement>(PositioningStrategy.DEFAULT)
     }
 
     val TYPES_AND_TYPE_PARAMETERS by object : DiagnosticGroup("Types & type parameters") {

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

@@ -425,6 +425,7 @@ object FirErrors {
     val AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER: KtDiagnosticFactory0 by error0<KtElement>(SourceElementPositioningStrategies.REFERENCE_BY_QUALIFIED)
     val UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL: KtDiagnosticFactory0 by error0<KtElement>(SourceElementPositioningStrategies.NAME_IDENTIFIER)
     val SUBTYPING_BETWEEN_CONTEXT_RECEIVERS: KtDiagnosticFactory0 by error0<KtElement>()
+    val CONTEXT_RECEIVERS_WITH_BACKING_FIELD: KtDiagnosticFactory0 by error0<KtElement>()
 
     // Types & type parameters
     val RECURSION_IN_IMPLICIT_TYPES: KtDiagnosticFactory0 by error0<PsiElement>()

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

@@ -264,6 +264,7 @@ val FIR_NON_SUPPRESSIBLE_ERROR_NAMES: Set<String> = setOf(
     "AMBIGUOUS_CALL_WITH_IMPLICIT_CONTEXT_RECEIVER",
     "UNSUPPORTED_CONTEXTUAL_DECLARATION_CALL",
     "SUBTYPING_BETWEEN_CONTEXT_RECEIVERS",
+    "CONTEXT_RECEIVERS_WITH_BACKING_FIELD",
     "RECURSION_IN_IMPLICIT_TYPES",
     "INFERENCE_ERROR",
     "PROJECTION_ON_NON_CLASS_TYPE_ARGUMENT",

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

@@ -91,6 +91,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             ContractSyntaxV2PropertyChecker,
             FirVolatileAnnotationChecker,
             FirInlinePropertyChecker,
+            FirContextReceiversPropertyBackingFieldChecker
         )
 
     override val backingFieldCheckers: Set<FirBackingFieldChecker>

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2023 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.config.LanguageFeature
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.fir.declarations.FirProperty
+import org.jetbrains.kotlin.fir.declarations.utils.hasBackingField
+
+object FirContextReceiversPropertyBackingFieldChecker : FirPropertyChecker() {
+    override fun check(declaration: FirProperty, context: CheckerContext, reporter: DiagnosticReporter) {
+        if (!context.languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)) return
+        if (declaration.contextReceivers.isEmpty()) return
+
+        if (declaration.hasBackingField) {
+            reporter.reportOn(
+                declaration.initializer?.source,
+                FirErrors.CONTEXT_RECEIVERS_WITH_BACKING_FIELD,
+                context
+            )
+        }
+    }
+}

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

@@ -154,6 +154,7 @@ import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONST_VAL_WITHOUT
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONST_VAL_WITH_DELEGATE
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONST_VAL_WITH_GETTER
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONST_VAL_WITH_NON_CONST_INITIALIZER
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONTEXT_RECEIVERS_WITH_BACKING_FIELD
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CONTRACT_NOT_ALLOWED
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CREATING_AN_INSTANCE_OF_ABSTRACT_CLASS
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors.CYCLE_IN_ANNOTATION_PARAMETER
@@ -1282,6 +1283,10 @@ object FirErrorsDefaultMessages : BaseDiagnosticRendererFactory() {
             SUBTYPING_BETWEEN_CONTEXT_RECEIVERS,
             "Subtyping relation between context receivers is prohibited."
         )
+        map.put(
+            CONTEXT_RECEIVERS_WITH_BACKING_FIELD,
+            "Property with context receivers cannot be initialized because it has no backing field."
+        )
 
         // Ambiguity
         map.put(OVERLOAD_RESOLUTION_AMBIGUITY, "Overload resolution ambiguity between candidates: {0}", SYMBOLS)

compiler/testData/diagnostics/tests/extensions/contextReceivers/noBackingField.fir.kt

@@ -1,17 +0,0 @@
-// !LANGUAGE: +ContextReceivers
-
-interface A {
-    fun a(): Int
-}
-interface B {
-    fun b(): Int
-}
-
-context(A)
-val a = 1
-
-context(A, B)
-var b = 2
-
-context(A, B)
-val c get() = a() + b()

compiler/testData/diagnostics/tests/extensions/contextReceivers/noBackingField.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: +ContextReceivers
 
 interface A {