[FE] Report ambiguity when label can refer to multiple receivers

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -10612,6 +10612,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                     runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/insideDeclaration.kt");
                 }
 
+                @Test
+                @TestMetadata("labelsFromClassNameForbidden.kt")
+                public void testLabelsFromClassNameForbidden() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.kt");
+                }
+
                 @Test
                 @TestMetadata("lazy.kt")
                 public void testLazy() throws Exception {

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

@@ -437,7 +437,7 @@ fun getDeclarationLabels(lambdaOrFun: PsiElement?, descriptor: DeclarationDescri
     val result = HashSet<String>()
 
     if (lambdaOrFun != null) {
-        val label = LabelResolver.getLabelNamesIfAny(lambdaOrFun, addContextReceiverNames = false)
+        val label = LabelResolver.getLabelNamesIfAny(lambdaOrFun, addClassNameLabels = false)
         if (label.isNotEmpty()) {
             result.add(label.single().asString())
         }

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

@@ -10612,6 +10612,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                     runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/insideDeclaration.kt");
                 }
 
+                @Test
+                @TestMetadata("labelsFromClassNameForbidden.kt")
+                public void testLabelsFromClassNameForbidden() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.kt");
+                }
+
                 @Test
                 @TestMetadata("lazy.kt")
                 public void testLazy() throws Exception {

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

@@ -10612,6 +10612,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                     runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/insideDeclaration.kt");
                 }
 
+                @Test
+                @TestMetadata("labelsFromClassNameForbidden.kt")
+                public void testLabelsFromClassNameForbidden() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.kt");
+                }
+
                 @Test
                 @TestMetadata("lazy.kt")
                 public void testLazy() throws Exception {

compiler/frontend/src/org/jetbrains/kotlin/resolve/FunctionDescriptorResolver.kt

@@ -228,32 +228,36 @@ class FunctionDescriptorResolver(
             }
         }
 
-        val receiverToLabelMap = linkedMapOf<ReceiverParameterDescriptor, String>()
         val extensionReceiver = receiverType?.let {
-            val splitter = AnnotationSplitter(storageManager, receiverType.annotations, EnumSet.of(AnnotationUseSiteTarget.RECEIVER))
+            val splitter = AnnotationSplitter(storageManager, it.annotations, EnumSet.of(AnnotationUseSiteTarget.RECEIVER))
             DescriptorFactory.createExtensionReceiverParameterForCallable(
                 functionDescriptor, it, splitter.getAnnotationsForTarget(AnnotationUseSiteTarget.RECEIVER)
             )
-        }?.apply {
-            val extensionReceiverName = receiverTypeRef?.nameForReceiverLabel()
-            if (extensionReceiverName != null) {
-                receiverToLabelMap[this] = extensionReceiverName
-            }
         }
-
+        val contextReceiverDescriptors = contextReceiverTypes.mapNotNull {
-        val contextReceiverDescriptors = contextReceiverTypes.mapNotNull { type ->
+            val splitter = AnnotationSplitter(storageManager, it.annotations, EnumSet.of(AnnotationUseSiteTarget.RECEIVER))
-            val splitter = AnnotationSplitter(storageManager, type.annotations, EnumSet.of(AnnotationUseSiteTarget.RECEIVER))
             DescriptorFactory.createContextReceiverParameterForCallable(
-                functionDescriptor, type, splitter.getAnnotationsForTarget(AnnotationUseSiteTarget.RECEIVER)
+                functionDescriptor, it, splitter.getAnnotationsForTarget(AnnotationUseSiteTarget.RECEIVER)
             )
         }
-        contextReceiverDescriptors.zip(0 until contextReceivers.size).reversed()
+
-            .forEach { (contextReceiverDescriptor, i) ->
+        if (languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)) {
-                contextReceivers[i].name()?.let {
+            val receiverToLabelMap = linkedMapOf<ReceiverParameterDescriptor, String>()
-                    receiverToLabelMap[contextReceiverDescriptor] = it
+            if (receiverTypeRef != null && extensionReceiver != null) {
+                receiverTypeRef.nameForReceiverLabel()?.let {
+                    receiverToLabelMap[extensionReceiver] = it
                 }
             }
-        trace.record(BindingContext.DESCRIPTOR_TO_NAMED_RECEIVERS, functionDescriptor, receiverToLabelMap)
+            contextReceiverDescriptors.zip(0 until contextReceivers.size).reversed()
+                .forEach { (contextReceiverDescriptor, i) ->
+                    contextReceivers[i].name()?.let {
+                        receiverToLabelMap[contextReceiverDescriptor] = it
+                    }
+                }
+
+            trace.record(BindingContext.DESCRIPTOR_TO_NAMED_RECEIVERS, functionDescriptor, receiverToLabelMap)
+        }
+
         functionDescriptor.initialize(
             extensionReceiver,
             getDispatchReceiverParameterIfNeeded(container),

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/LabelResolver.kt

@@ -17,6 +17,7 @@
 package org.jetbrains.kotlin.types.expressions
 
 import com.intellij.psi.PsiElement
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.diagnostics.Errors.LABEL_NAME_CLASH
 import org.jetbrains.kotlin.diagnostics.Errors.UNRESOLVED_REFERENCE
@@ -33,12 +34,12 @@ object LabelResolver {
     private fun getElementsByLabelName(
         labelName: Name,
         labelExpression: KtSimpleNameExpression,
-        isThisExpression: Boolean
+        classNameLabelsEnabled: Boolean
     ): Set<KtElement> {
         val elements = linkedSetOf<KtElement>()
         var parent: PsiElement? = labelExpression.parent
         while (parent != null) {
-            val names = getLabelNamesIfAny(parent, isThisExpression)
+            val names = getLabelNamesIfAny(parent, classNameLabelsEnabled)
             if (names.contains(labelName)) {
                 elements.add(getExpressionUnderLabel(parent as KtExpression))
             }
@@ -47,7 +48,7 @@ object LabelResolver {
         return elements
     }
 
-    fun getLabelNamesIfAny(element: PsiElement, addContextReceiverNames: Boolean): List<Name> {
+    fun getLabelNamesIfAny(element: PsiElement, addClassNameLabels: Boolean): List<Name> {
         val result = mutableListOf<Name>()
         when (element) {
             is KtLabeledExpression -> result.addIfNotNull(element.getLabelNameAsName())
@@ -60,10 +61,10 @@ object LabelResolver {
             is KtPropertyAccessor -> element.property
             else -> return result
         }
-        if (addContextReceiverNames) {
+        if (addClassNameLabels) {
+            functionOrProperty.receiverTypeReference?.nameForReceiverLabel()?.let { result.add(Name.identifier(it)) }
             functionOrProperty.contextReceivers
                 .mapNotNullTo(result) { it.name()?.let { s -> Name.identifier(s) } }
-            functionOrProperty.receiverTypeReference?.nameForReceiverLabel()?.let { result.add(Name.identifier(it)) }
         }
         val name = functionOrProperty.nameAsName ?: getLabelForFunctionalExpression(functionOrProperty)
         result.addIfNotNull(name)
@@ -129,9 +130,9 @@ object LabelResolver {
         labelName: Name,
         labelExpression: KtSimpleNameExpression,
         trace: BindingTrace,
-        isThisExpression: Boolean
+        classNameLabelsEnabled: Boolean
     ): KtElement? {
-        val list = getElementsByLabelName(labelName, labelExpression, isThisExpression)
+        val list = getElementsByLabelName(labelName, labelExpression, classNameLabelsEnabled)
         if (list.isEmpty()) return null
 
         if (list.size > 1) {
@@ -175,15 +176,28 @@ object LabelResolver {
                 return LabeledReceiverResolutionResult.labelResolutionSuccess(thisReceiver)
             }
             0 -> {
-                val element = resolveNamedLabel(labelName, targetLabel, context.trace, expression is KtThisExpression)
+                val element = resolveNamedLabel(
+                    labelName, targetLabel, context.trace,
+                    classNameLabelsEnabled = expression is KtThisExpression
+                            && context.languageVersionSettings.supportsFeature(LanguageFeature.ContextReceivers)
+                )
                 val declarationDescriptor = context.trace.bindingContext[DECLARATION_TO_DESCRIPTOR, element]
                 if (declarationDescriptor is FunctionDescriptor) {
-                    val receiverToLabelMap =
+                    val receiverToLabelMap = context.trace.bindingContext[
-                        context.trace.bindingContext[DESCRIPTOR_TO_NAMED_RECEIVERS, if (declarationDescriptor is PropertyAccessorDescriptor) declarationDescriptor.correspondingProperty else declarationDescriptor]
+                            DESCRIPTOR_TO_NAMED_RECEIVERS,
-                    val thisReceiver = receiverToLabelMap?.entries?.find {
+                            if (declarationDescriptor is PropertyAccessorDescriptor) declarationDescriptor.correspondingProperty else declarationDescriptor
+                    ]
+                    val thisReceivers = receiverToLabelMap?.entries?.filter {
                         it.value == labelName.identifier
-                    }?.key ?: declarationDescriptor.extensionReceiverParameter
+                    }?.map { it.key } ?: emptyList()
-                    if (thisReceiver != null) {
+                    val thisReceiver = when {
+                        thisReceivers.isEmpty() -> declarationDescriptor.extensionReceiverParameter
+                        thisReceivers.size == 1 -> thisReceivers.single()
+                        else -> {
+                            BindingContextUtils.reportAmbiguousLabel(context.trace, targetLabel, declarationsByLabel)
+                            return LabeledReceiverResolutionResult.labelResolutionFailed()
+                        }
+                    }?.also {
                         context.trace.record(LABEL_TARGET, targetLabel, element)
                         context.trace.record(REFERENCE_TARGET, referenceExpression, declarationDescriptor)
                     }

compiler/testData/diagnostics/tests/extensions/contextReceivers/fromKEEP/decimateEveryEvenThird.fir.kt

@@ -1,3 +1,4 @@
+// !LANGUAGE: +ContextReceivers
 // WITH_RUNTIME
 
 fun List<Int>.decimateEveryEvenThird() = <!NEW_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>sequence<!> {

compiler/testData/diagnostics/tests/extensions/contextReceivers/fromKEEP/decimateEveryEvenThird.kt

@@ -1,3 +1,4 @@
+// !LANGUAGE: +ContextReceivers
 // WITH_RUNTIME
 
 fun List<Int>.decimateEveryEvenThird() = sequence {

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

@@ -0,0 +1,12 @@
+fun List<Int>.f() {
+    this<!UNRESOLVED_LABEL!>@List<!>.size
+}
+
+context(String)
+fun Int.f() {
+    this<!UNRESOLVED_LABEL!>@String<!>.length
+    this<!UNRESOLVED_LABEL!>@Int<!>.toDouble()
+}
+
+context(String)
+val p: String get() = this<!UNRESOLVED_LABEL!>@String<!>

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

@@ -0,0 +1,12 @@
+fun List<Int>.f() {
+    this<!UNRESOLVED_REFERENCE!>@List<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>size<!>
+}
+
+<!UNSUPPORTED_FEATURE!>context(String)<!>
+fun Int.f() {
+    this<!UNRESOLVED_REFERENCE!>@String<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
+    this<!UNRESOLVED_REFERENCE!>@Int<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>toDouble<!>()
+}
+
+<!UNSUPPORTED_FEATURE!>context(String)<!>
+val p: String get() = this<!UNRESOLVED_REFERENCE!>@String<!>

compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.txt

@@ -0,0 +1,5 @@
+package
+
+public val p: kotlin.String
+public fun kotlin.Int.f(): kotlin.Unit
+public fun kotlin.collections.List<kotlin.Int>.f(): kotlin.Unit

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

@@ -4,7 +4,17 @@ class A<T>(val a: T)
 class B(val b: Any)
 class C(val c: Any)
 
-context(A<Int>, A<String>, B) fun f() {
+context(A<String>) fun A<Int>.f() {
+    this<!UNRESOLVED_LABEL!>@A<!>.a.length
+}
+
+<!CONFLICTING_OVERLOADS!>context(A<String>, B) fun f()<!> {
+    this<!UNRESOLVED_LABEL!>@A<!>.a.length
+    this<!UNRESOLVED_LABEL!>@B<!>.b
+    <!NO_THIS!>this<!>
+}
+
+<!CONFLICTING_OVERLOADS!>context(A<Int>, A<String>, B) fun f()<!> {
     this<!UNRESOLVED_LABEL!>@A<!>.a.length
     this<!UNRESOLVED_LABEL!>@B<!>.b
     <!NO_THIS!>this<!>

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

@@ -4,14 +4,24 @@ class A<T>(val a: T)
 class B(val b: Any)
 class C(val c: Any)
 
-context(A<Int>, A<String>, B) fun f() {
+context(A<String>) fun A<Int>.f() {
+    this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
+}
+
+context(A<String>, B) fun f() {
     this@A.a.length
     this@B.b
     <!NO_THIS!>this<!>
 }
 
+context(A<Int>, A<String>, B) fun f() {
+    this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
+    this@B.b
+    <!NO_THIS!>this<!>
+}
+
 context(A<Int>, A<String>, B) fun C.f() {
-    this@A.a.length
+    this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
     this@B.b
     this@C.c
     this@f.c

compiler/testData/diagnostics/tests/extensions/contextReceivers/thisWithReceiverLabelsFunctions.txt

@@ -1,6 +1,8 @@
 package
 
 public fun f(): kotlin.Unit
+public fun f(): kotlin.Unit
+public fun A<kotlin.Int>.f(): kotlin.Unit
 public fun C.f(): kotlin.Unit
 
 public final class A</*0*/ T> {
@@ -26,3 +28,4 @@ public final class C {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }
+

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

@@ -4,7 +4,21 @@ class A<T>(val a: T)
 class B(val b: Any)
 class C(val c: Any)
 
-<!MUST_BE_INITIALIZED!>context(A<Int>, A<String>, B) var p: Int<!>
+<!MUST_BE_INITIALIZED!>context(A<String>, B) var <!REDECLARATION!>p<!>: Int<!>
+    get() {
+        this<!UNRESOLVED_LABEL!>@A<!>.a.length
+        this<!UNRESOLVED_LABEL!>@B<!>.b
+        <!NO_THIS!>this<!>
+        return 1
+    }
+    set(value) {
+        this<!UNRESOLVED_LABEL!>@A<!>.a.length
+        this<!UNRESOLVED_LABEL!>@B<!>.b
+        <!NO_THIS!>this<!>
+        field = value
+    }
+
+<!MUST_BE_INITIALIZED!>context(A<Int>, A<String>, B) var <!REDECLARATION!>p<!>: Int<!>
     get() {
         this<!UNRESOLVED_LABEL!>@A<!>.a.toDouble()
         this<!UNRESOLVED_LABEL!>@A<!>.a.length

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

@@ -4,9 +4,8 @@ class A<T>(val a: T)
 class B(val b: Any)
 class C(val c: Any)
 
-context(A<Int>, A<String>, B) var p: Int
+context(A<String>, B) var p: Int
     get() {
-        this@A.a.<!UNRESOLVED_REFERENCE!>toDouble<!>()
         this@A.a.length
         this@B.b
         <!NO_THIS!>this<!>
@@ -19,9 +18,24 @@ context(A<Int>, A<String>, B) var p: Int
         <!UNRESOLVED_REFERENCE!>field<!> = value
     }
 
+context(A<Int>, A<String>, B) var p: Int
+    get() {
+        this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>toDouble<!>()
+        this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
+        this@B.b
+        <!NO_THIS!>this<!>
+        return 1
+    }
+    set(value) {
+        this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
+        this@B.b
+        <!NO_THIS!>this<!>
+        <!UNRESOLVED_REFERENCE!>field<!> = value
+    }
+
 context(A<Int>, A<String>, B) val C.p: Int
     get() {
-        this@A.a.length
+        this<!AMBIGUOUS_LABEL!>@A<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>a<!>.<!DEBUG_INFO_MISSING_UNRESOLVED!>length<!>
         this@B.b
         this@C.c
         this@p.c

compiler/testData/diagnostics/tests/extensions/contextReceivers/thisWithReceiverLabelsProperties.txt

@@ -1,5 +1,6 @@
 package
 
+public var p: kotlin.Int
 public var p: kotlin.Int
 public val C.p: kotlin.Int
 

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -10618,6 +10618,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                     runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/insideDeclaration.kt");
                 }
 
+                @Test
+                @TestMetadata("labelsFromClassNameForbidden.kt")
+                public void testLabelsFromClassNameForbidden() throws Exception {
+                    runTest("compiler/testData/diagnostics/tests/extensions/contextReceivers/labelsFromClassNameForbidden.kt");
+                }
+
                 @Test
                 @TestMetadata("lazy.kt")
                 public void testLazy() throws Exception {