[FIR] Add proper nullability for java enums

compiler/fir/analysis-tests/testData/enhancement/signatureAnnotations/DefaultEnum.fir.txt

@@ -11,7 +11,7 @@ public/*package*/ open class A : R|kotlin/Any| {
 
 }
 public final enum class Mixed : R|kotlin/Enum<ft<Mixed, Mixed?>!>| {
-    public final static field NOT_ENTRY_EITHER: R|ft<Mixed, Mixed?>!|
+    public final static field NOT_ENTRY_EITHER: R|Mixed|
 
     public final static fun values(): R|kotlin/Array<Mixed>| {
     }
@@ -21,9 +21,9 @@ public final enum class Mixed : R|kotlin/Enum<ft<Mixed, Mixed?>!>| {
 
 }
 public final enum class Signs : R|kotlin/Enum<ft<Signs, Signs?>!>| {
-    public final static field HELLO: R|ft<Signs, Signs?>!|
+    public final static field HELLO: R|Signs|
 
-    public final static field WORLD: R|ft<Signs, Signs?>!|
+    public final static field WORLD: R|Signs|
 
     public final static field X: R|ft<Signs, Signs?>!|
 

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/JavaSymbolProvider.kt

@@ -16,6 +16,7 @@ import org.jetbrains.kotlin.fir.declarations.FirRegularClass
 import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.declarations.addDefaultBoundIfNecessary
 import org.jetbrains.kotlin.fir.declarations.builder.FirTypeParameterBuilder
+import org.jetbrains.kotlin.fir.expressions.builder.buildAnnotationCall
 import org.jetbrains.kotlin.fir.java.declarations.*
 import org.jetbrains.kotlin.fir.resolve.AbstractFirSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.constructType
@@ -194,6 +195,7 @@ class JavaSymbolProvider(
                             returnTypeRef = returnType.toFirJavaTypeRef(this@JavaSymbolProvider.session, javaTypeParameterStack)
                             isVar = !javaField.isFinal
                             isStatic = javaField.isStatic
+                            isEnumEntry = javaField.isEnumEntry
                             addAnnotationsFrom(this@JavaSymbolProvider.session, javaField, javaTypeParameterStack)
                         }
                         declarations += firJavaField

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/declarations/FirJavaField.kt

@@ -42,6 +42,7 @@ class FirJavaField @FirImplementationDetail constructor(
     override val isVar: Boolean,
     override val annotations: MutableList<FirAnnotationCall>,
     override val typeParameters: MutableList<FirTypeParameter>,
+    val isEnumEntry: Boolean
 ) : FirField() {
     init {
         symbol.bind(this)
@@ -127,6 +128,7 @@ internal class FirJavaFieldBuilder : FirFieldBuilder() {
     var modality: Modality? = null
     lateinit var visibility: Visibility
     var isStatic: Boolean by Delegates.notNull()
+    var isEnumEntry: Boolean by Delegates.notNull()
 
     override var resolvePhase: FirResolvePhase = FirResolvePhase.ANALYZED_DEPENDENCIES
 
@@ -149,7 +151,8 @@ internal class FirJavaFieldBuilder : FirFieldBuilder() {
             status,
             isVar,
             annotations,
-            typeParameters
+            typeParameters,
+            isEnumEntry
         )
     }
 }

compiler/fir/java/src/org/jetbrains/kotlin/fir/java/scopes/JavaClassEnhancementScope.kt

@@ -33,8 +33,7 @@ import org.jetbrains.kotlin.fir.types.jvm.FirJavaTypeRef
 import org.jetbrains.kotlin.load.java.AnnotationTypeQualifierResolver
 import org.jetbrains.kotlin.load.java.descriptors.NullDefaultValue
 import org.jetbrains.kotlin.load.java.descriptors.StringDefaultValue
-import org.jetbrains.kotlin.load.java.typeEnhancement.PREDEFINED_FUNCTION_ENHANCEMENT_INFO_BY_SIGNATURE
+import org.jetbrains.kotlin.load.java.typeEnhancement.*
-import org.jetbrains.kotlin.load.java.typeEnhancement.PredefinedFunctionEnhancementInfo
 import org.jetbrains.kotlin.load.kotlin.SignatureBuildingComponents
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.utils.Jsr305State
@@ -89,7 +88,18 @@ class JavaClassEnhancementScope(
             is FirField -> {
                 if (firElement.returnTypeRef !is FirJavaTypeRef) return original
                 val memberContext = context.copyWithNewDefaultTypeQualifiers(typeQualifierResolver, jsr305State, firElement.annotations)
-                val newReturnTypeRef = enhanceReturnType(firElement, emptyList(), memberContext, null)
+                val isEnumEntry = (firElement as? FirJavaField)?.isEnumEntry ?: false
+
+                val predefinedInfo = if (isEnumEntry) {
+                    PredefinedFunctionEnhancementInfo(
+                        TypeEnhancementInfo(0 to JavaTypeQualifiers(NullabilityQualifier.NOT_NULL, null, false)),
+                        emptyList()
+                    )
+                } else {
+                    null
+                }
+
+                val newReturnTypeRef = enhanceReturnType(firElement, emptyList(), memberContext, predefinedInfo)
 
                 val symbol = FirFieldSymbol(original.callableId)
                 buildJavaField {
@@ -103,6 +113,7 @@ class JavaClassEnhancementScope(
                     isVar = firElement.isVar
                     isStatic = firElement.isStatic
                     annotations += firElement.annotations
+                    this.isEnumEntry = isEnumEntry
                 }
                 return symbol
             }

compiler/testData/ir/irText/stubs/javaEnum.fir.txt

@@ -1,10 +1,10 @@
 FILE fqName:<root> fileName:/javaEnum.kt
   PROPERTY name:test visibility:public modality:FINAL [val]
-    FIELD PROPERTY_BACKING_FIELD name:test type:<root>.JEnum? visibility:private [final,static]
+    FIELD PROPERTY_BACKING_FIELD name:test type:<root>.JEnum visibility:private [final,static]
       EXPRESSION_BODY
-        GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:ONE type:<root>.JEnum? visibility:public [final,static]' type=<root>.JEnum? origin=GET_PROPERTY
+        GET_FIELD 'FIELD IR_EXTERNAL_JAVA_DECLARATION_STUB name:ONE type:<root>.JEnum visibility:public [final,static]' type=<root>.JEnum origin=GET_PROPERTY
-    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test> visibility:public modality:FINAL <> () returnType:<root>.JEnum?
+    FUN DEFAULT_PROPERTY_ACCESSOR name:<get-test> visibility:public modality:FINAL <> () returnType:<root>.JEnum
       correspondingProperty: PROPERTY name:test visibility:public modality:FINAL [val]
       BLOCK_BODY
-        RETURN type=kotlin.Nothing from='public final fun <get-test> (): <root>.JEnum? declared in <root>'
+        RETURN type=kotlin.Nothing from='public final fun <get-test> (): <root>.JEnum declared in <root>'
-          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test type:<root>.JEnum? visibility:private [final,static]' type=<root>.JEnum? origin=null
+          GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:test type:<root>.JEnum visibility:private [final,static]' type=<root>.JEnum origin=null

compiler/testData/loadJava/compiledJava/annotations/AnnotatedEnumEntry.fir.txt

@@ -1,9 +1,9 @@
 public final enum class AnnotatedEnumEntry : R|kotlin/Enum<ft<test/AnnotatedEnumEntry, test/AnnotatedEnumEntry?>!>| {
-    @R|test/AnnotatedEnumEntry.Anno|(String(a)) public final static field E1: R|ft<test/AnnotatedEnumEntry, test/AnnotatedEnumEntry?>!|
+    @R|test/AnnotatedEnumEntry.Anno|(String(a)) public final static field E1: R|test/AnnotatedEnumEntry|
 
-    @R|test/AnnotatedEnumEntry.Anno|(String(b)) @R|test/AnnotatedEnumEntry.Anno2|() public final static field E2: R|ft<test/AnnotatedEnumEntry, test/AnnotatedEnumEntry?>!|
+    @R|test/AnnotatedEnumEntry.Anno|(String(b)) @R|test/AnnotatedEnumEntry.Anno2|() public final static field E2: R|test/AnnotatedEnumEntry|
 
-    public final static field E3: R|ft<test/AnnotatedEnumEntry, test/AnnotatedEnumEntry?>!|
+    public final static field E3: R|test/AnnotatedEnumEntry|
 
     public final static fun values(): R|kotlin/Array<test/AnnotatedEnumEntry>| {
     }

compiler/testData/loadJava/compiledJava/annotations/EnumConstructorParameter.fir.txt

@@ -1,5 +1,5 @@
 public final enum class EnumConstructorParameter : R|kotlin/Enum<ft<test/EnumConstructorParameter, test/EnumConstructorParameter?>!>| {
-    public final static field INSTANCE: R|ft<test/EnumConstructorParameter, test/EnumConstructorParameter?>!|
+    public final static field INSTANCE: R|test/EnumConstructorParameter|
 
     private constructor(@R|test/EnumConstructorParameter.Anno|(String(string)) s: R|ft<kotlin/String, kotlin/String?>!|): R|test/EnumConstructorParameter|
 

compiler/testData/loadJava/compiledJava/enum/EnumMembers.fir.txt

@@ -1,7 +1,7 @@
 public final enum class EnumMembers : R|kotlin/Enum<ft<test/EnumMembers, test/EnumMembers?>!>| {
-    public final static field FIRST: R|ft<test/EnumMembers, test/EnumMembers?>!|
+    public final static field FIRST: R|test/EnumMembers|
 
-    public final static field SECOND: R|ft<test/EnumMembers, test/EnumMembers?>!|
+    public final static field SECOND: R|test/EnumMembers|
 
     public final field isFirst: R|kotlin/Boolean|
 

compiler/testData/loadJava/compiledJava/enum/EnumWithSpecializedEntry.fir.txt

@@ -1,7 +1,7 @@
 public open enum class EnumWithSpecializedEntry : R|kotlin/Enum<ft<test/EnumWithSpecializedEntry, test/EnumWithSpecializedEntry?>!>| {
-    public final static field E1: R|ft<test/EnumWithSpecializedEntry, test/EnumWithSpecializedEntry?>!|
+    public final static field E1: R|test/EnumWithSpecializedEntry|
 
-    public final static field E2: R|ft<test/EnumWithSpecializedEntry, test/EnumWithSpecializedEntry?>!|
+    public final static field E2: R|test/EnumWithSpecializedEntry|
 
     public final static fun values(): R|kotlin/Array<test/EnumWithSpecializedEntry>| {
     }

compiler/testData/loadJava/compiledJava/enum/JavaEnum.fir.txt

@@ -1,7 +1,7 @@
 public final enum class JavaEnum : R|kotlin/Enum<ft<test/JavaEnum, test/JavaEnum?>!>| {
-    public final static field ENTRY: R|ft<test/JavaEnum, test/JavaEnum?>!|
+    public final static field ENTRY: R|test/JavaEnum|
 
-    public final static field ANOTHER: R|ft<test/JavaEnum, test/JavaEnum?>!|
+    public final static field ANOTHER: R|test/JavaEnum|
 
     public final static fun values(): R|kotlin/Array<test/JavaEnum>| {
     }

compiler/testData/loadJava/compiledJava/static/Enum.fir.txt

@@ -1,9 +1,9 @@
 public final enum class Enum : R|kotlin/Enum<ft<test/Enum, test/Enum?>!>| {
-    public final static field A: R|ft<test/Enum, test/Enum?>!|
+    public final static field A: R|test/Enum|
 
-    public final static field B: R|ft<test/Enum, test/Enum?>!|
+    public final static field B: R|test/Enum|
 
-    public final static field C: R|ft<test/Enum, test/Enum?>!|
+    public final static field C: R|test/Enum|
 
     public final static fun values(): R|kotlin/Array<test/Enum>| {
     }

compiler/testData/loadJava/compiledJava/static/StaticMembersInEnum.fir.txt

@@ -1,5 +1,5 @@
 public final enum class StaticMembersInEnum : R|kotlin/Enum<ft<test/StaticMembersInEnum, test/StaticMembersInEnum?>!>| {
-    public final static field ENTRY: R|ft<test/StaticMembersInEnum, test/StaticMembersInEnum?>!|
+    public final static field ENTRY: R|test/StaticMembersInEnum|
 
     public open static field STATIC_FIELD: R|kotlin/Int|