[FIR] Support static getters along with fake Enum.entries declaration in FIR

#KT-48872

compiler/fir/tree/src/org/jetbrains/kotlin/fir/EnumClassUtils.kt

@@ -7,22 +7,24 @@ package org.jetbrains.kotlin.fir
 
 import org.jetbrains.kotlin.KtFakeSourceElementKind
 import org.jetbrains.kotlin.builtins.StandardNames.DEFAULT_VALUE_PARAMETER
+import org.jetbrains.kotlin.builtins.StandardNames.ENUM_ENTRIES
 import org.jetbrains.kotlin.builtins.StandardNames.ENUM_VALUES
 import org.jetbrains.kotlin.builtins.StandardNames.ENUM_VALUE_OF
+import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fakeElement
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationOrigin
 import org.jetbrains.kotlin.fir.declarations.FirDeclarationStatus
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
-import org.jetbrains.kotlin.fir.declarations.builder.FirRegularClassBuilder
-import org.jetbrains.kotlin.fir.declarations.builder.buildSimpleFunction
-import org.jetbrains.kotlin.fir.declarations.builder.buildValueParameter
+import org.jetbrains.kotlin.fir.declarations.builder.*
 import org.jetbrains.kotlin.fir.declarations.impl.FirDeclarationStatusImpl
+import org.jetbrains.kotlin.fir.declarations.impl.FirDefaultPropertyGetter
 import org.jetbrains.kotlin.fir.declarations.impl.FirResolvedDeclarationStatusImpl
 import org.jetbrains.kotlin.fir.expressions.builder.buildEmptyExpressionBlock
 import org.jetbrains.kotlin.fir.symbols.impl.ConeClassLikeLookupTagImpl
 import org.jetbrains.kotlin.fir.symbols.impl.FirNamedFunctionSymbol
+import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirValueParameterSymbol
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef
 import org.jetbrains.kotlin.fir.types.impl.ConeClassLikeTypeImpl
@@ -114,6 +116,49 @@ fun FirRegularClassBuilder.generateValueOfFunction(
     }
 }
 
+fun FirRegularClassBuilder.generateEntriesGetter(
+    moduleData: FirModuleData, packageFqName: FqName, classFqName: FqName, makeExpect: Boolean = false
+) {
+    if (!moduleData.session.languageVersionSettings.supportsFeature(LanguageFeature.EnumEntries)) {
+        return
+    }
+
+    val sourceElement = source?.fakeElement(KtFakeSourceElementKind.EnumGeneratedDeclaration)
+    declarations += buildProperty {
+        source = sourceElement
+        isVar = false
+        isLocal = false
+        origin = FirDeclarationOrigin.Source
+        this.moduleData = moduleData
+        returnTypeRef = buildResolvedTypeRef {
+            source = sourceElement
+            type = ConeClassLikeTypeImpl(
+                ConeClassLikeLookupTagImpl(StandardClassIds.EnumEntries),
+                arrayOf(
+                    ConeClassLikeTypeImpl(this@generateEntriesGetter.symbol.toLookupTag(), emptyArray(), isNullable = false)
+                ),
+                isNullable = false
+            )
+        }
+        name = ENUM_ENTRIES
+        this.status = createStatus(this@generateEntriesGetter.status).apply {
+            isStatic = true
+            isExpect = makeExpect
+        }
+        symbol = FirPropertySymbol(CallableId(packageFqName, classFqName, ENUM_ENTRIES))
+        resolvePhase = FirResolvePhase.BODY_RESOLVE
+        getter = FirDefaultPropertyGetter(
+            sourceElement?.fakeElement(KtFakeSourceElementKind.EnumGeneratedDeclaration),
+            moduleData, FirDeclarationOrigin.Source, returnTypeRef.copyWithNewSourceKind(KtFakeSourceElementKind.EnumGeneratedDeclaration),
+            Visibilities.Public, symbol
+        ).apply {
+            (status as FirDeclarationStatusImpl).isStatic = true
+        }
+    }.apply {
+        containingClassForStaticMemberAttr = this@generateEntriesGetter.symbol.toLookupTag()
+    }
+}
+
 private fun createStatus(parentStatus: FirDeclarationStatus): FirDeclarationStatusImpl {
     val parentEffectiveVisibility = (parentStatus as? FirResolvedDeclarationStatusImpl)?.effectiveVisibility
     return if (parentEffectiveVisibility != null) {

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/utils/declarationAttributes.kt

@@ -77,6 +77,7 @@ val FirProperty.hasBackingField: Boolean
         if (isAbstract) return false
         if (delegate != null) return false
         if (hasExplicitBackingField) return true
+        if (isStatic) return false // For Enum.entries
         when (origin) {
             FirDeclarationOrigin.SubstitutionOverride -> return false
             FirDeclarationOrigin.IntersectionOverride -> return false