Add a warning for a custom Enum.entries entry

^KT-53153

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/Errors.java

@@ -143,6 +143,7 @@ public interface Errors {
     DiagnosticFactory1<PsiElement, PropertyDescriptor> DEPRECATED_ACCESS_TO_ENUM_COMPANION_PROPERTY = DiagnosticFactory1.create(WARNING);
 
     DiagnosticFactory0<PsiElement> DEPRECATED_ACCESS_TO_ENUM_ENTRY_COMPANION_PROPERTY = DiagnosticFactory0.create(WARNING);
+    DiagnosticFactory0<KtEnumEntry> DEPRECATED_DECLARATION_OF_ENUM_ENTRY = DiagnosticFactory0.create(WARNING);
 
     DiagnosticFactory2<PsiElement, PropertyDescriptor, ClassDescriptor> DEPRECATED_RESOLVE_WITH_AMBIGUOUS_ENUM_ENTRY = DiagnosticFactory2.create(WARNING);
 

compiler/frontend/src/org/jetbrains/kotlin/diagnostics/rendering/DefaultErrorMessages.java

@@ -74,6 +74,7 @@ public class DefaultErrorMessages {
         MAP.put(DEPRECATED_ACCESS_BY_SHORT_NAME, "Access to this type by short name is deprecated, and soon is going to be removed. Please, add explicit qualifier or import", NAME);
         MAP.put(DEPRECATED_ACCESS_TO_ENUM_COMPANION_PROPERTY, "Ambiguous access to companion''s property ''{0}'' in enum is deprecated. Please, add explicit Companion qualifier to the class name", NAME);
         MAP.put(DEPRECATED_ACCESS_TO_ENUM_ENTRY_COMPANION_PROPERTY, "Ambiguous access to companion''s property 'entries' in enum is deprecated. Please, add explicit Companion qualifier to the class name");
+        MAP.put(DEPRECATED_DECLARATION_OF_ENUM_ENTRY, "Conflicting declarations: enum entry 'entries' and the property 'Enum.entries' (KT-48872). Please, rename the enum entry declaration");
         MAP.put(DEPRECATED_RESOLVE_WITH_AMBIGUOUS_ENUM_ENTRY, "Ambiguous access to property ''{0}'' is deprecated because similar enum entry ''{1}'' is available. Please add explicit named import or use fully qualified name", FQ_NAME, FQ_NAME);
 
         MAP.put(PROTECTED_CONSTRUCTOR_NOT_IN_SUPER_CALL, "Protected constructor ''{0}'' from other classes can only be used in super-call", Renderers.SHORT_NAMES_IN_TYPES);

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

@@ -54,6 +54,7 @@ private val DEFAULT_DECLARATION_CHECKERS = listOf(
     CyclicAnnotationsChecker,
     UnsupportedUntilRangeDeclarationChecker,
     DataObjectContentChecker,
+    EnumEntriesRedeclarationChecker,
 )
 
 private val DEFAULT_CALL_CHECKERS = listOf(

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/EnumEntriesRedeclarationChecker.kt

@@ -0,0 +1,20 @@
+/*
+ * 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.resolve.checkers
+
+import org.jetbrains.kotlin.builtins.StandardNames
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.psi.KtDeclaration
+import org.jetbrains.kotlin.psi.KtEnumEntry
+
+object EnumEntriesRedeclarationChecker : DeclarationChecker {
+    override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
+        if (declaration !is KtEnumEntry || declaration.name != StandardNames.ENUM_ENTRIES.asString()) return
+
+        context.trace.report(Errors.DEPRECATED_DECLARATION_OF_ENUM_ENTRY.on(declaration))
+    }
+}