FIR LC: revisit when to add fields to companion and/or containing class

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/classes/FirLightClassForClassOrObjectSymbol.kt

@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.psi.KtClassBody
 import org.jetbrains.kotlin.psi.KtClassOrObject
 import org.jetbrains.kotlin.psi.debugText.getDebugText
 import org.jetbrains.kotlin.psi.stubs.KotlinClassOrObjectStub
+import org.jetbrains.kotlin.utils.addToStdlib.applyIf
 import org.jetbrains.kotlin.utils.addToStdlib.ifFalse
 import org.jetbrains.kotlin.utils.addToStdlib.ifTrue
 
@@ -101,7 +102,9 @@ internal abstract class FirLightClassForClassOrObjectSymbol(
             analyzeWithSymbolAsContext(this) {
                 getDeclaredMemberScope().getCallableSymbols()
                     .filterIsInstance<KtPropertySymbol>()
-                    .filter { it.hasJvmFieldAnnotation() || it.hasJvmStaticAnnotation() || it is KtKotlinPropertySymbol && it.isConst }
+                    .applyIf(isInterface) {
+                        filter { it.hasJvmFieldAnnotation() || it.isConst }
+                    }
                     .mapTo(result) {
                         FirLightFieldForPropertySymbol(
                             propertySymbol = it,
@@ -109,7 +112,7 @@ internal abstract class FirLightClassForClassOrObjectSymbol(
                             containingClass = this@FirLightClassForClassOrObjectSymbol,
                             lightMemberOrigin = null,
                             isTopLevel = false,
-                            forceStatic = !it.hasJvmStaticAnnotation(),
+                            forceStatic = true,
                             takePropertyVisibility = true
                         )
                     }
@@ -117,6 +120,9 @@ internal abstract class FirLightClassForClassOrObjectSymbol(
         }
     }
 
+    private val KtPropertySymbol.isConst: Boolean
+        get() = (this as? KtKotlinPropertySymbol)?.isConst == true
+
     private val _containingFile: PsiFile? by lazyPub {
 
         val kotlinOrigin = kotlinOrigin ?: return@lazyPub null

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/classes/FirLightClassForSymbol.kt

@@ -246,7 +246,10 @@ internal open class FirLightClassForSymbol(
             val propertySymbols = classOrObjectSymbol.getDeclaredMemberScope().getCallableSymbols()
                 .filterIsInstance<KtPropertySymbol>()
                 .applyIf(classOrObjectSymbol.isCompanionObject) {
-                    filterNot { it.hasJvmFieldAnnotation() || it is KtKotlinPropertySymbol && it.isConst }
+                    // All fields for companion object of classes are generated to the containing class
+                    // For interfaces, only @JvmField-annotated properties are generated to the containing class
+                    // Probably, the same should work for const vals but it doesn't at the moment (see KT-28294)
+                    filter { containingClass?.isInterface == true && !it.hasJvmFieldAnnotation() }
                 }
             val propertyGroups = propertySymbols.groupBy { it.isFromPrimaryConstructor }
 

compiler/testData/asJava/lightClasses/compilationErrors/TraitClassObjectField.fir.java

@@ -7,6 +7,9 @@ public abstract interface TraitClassObjectField /* TraitClassObjectField*/ {
 
 
 public static final class Companion /* TraitClassObjectField.Companion*/ {
+  @org.jetbrains.annotations.Nullable()
+  private final java.lang.String x = "" /* initializer type: java.lang.String */;
+
   @org.jetbrains.annotations.Nullable()
   private final java.lang.String y;
 

compiler/testData/asJava/lightClasses/ideRegression/ImplementingMutableSet.fir.java

@@ -7,6 +7,8 @@ public final class SmartSet /* SmartSet*/<T>  extends kotlin.collections.Abstrac
 
   private int size;
 
+  private static final int ARRAY_THRESHOLD;
+
   @kotlin.jvm.JvmStatic()
   @org.jetbrains.annotations.NotNull()
   public static final <T> SmartSet<T> create();// <T>  create()
@@ -30,8 +32,6 @@ public final class SmartSet /* SmartSet*/<T>  extends kotlin.collections.Abstrac
 
 
 public static final class Companion /* SmartSet.Companion*/ {
-  private final int ARRAY_THRESHOLD;
-
   @kotlin.jvm.JvmStatic()
   @org.jetbrains.annotations.NotNull()
   public final <T> SmartSet<T> create();// <T>  create()
@@ -42,4 +42,4 @@ public static final class Companion /* SmartSet.Companion*/ {
 
   private  Companion();//  .ctor()
 
-}}
+}}

compiler/testData/asJava/lightClasses/nullabilityAnnotations/ClassObjectField.fir.java

@@ -2,16 +2,16 @@ public final class ClassObjectField /* ClassObjectField*/ {
   @org.jetbrains.annotations.NotNull()
   public static final ClassObjectField.Companion Companion;
 
+  @org.jetbrains.annotations.Nullable()
+  private static final java.lang.String y;
+
+  @org.jetbrains.annotations.Nullable()
+  public static final java.lang.String x;
+
   public  ClassObjectField();//  .ctor()
 
 
 public static final class Companion /* ClassObjectField.Companion*/ {
-  @org.jetbrains.annotations.Nullable()
-  private final java.lang.String x;
-
-  @org.jetbrains.annotations.Nullable()
-  private final java.lang.String y;
-
   @org.jetbrains.annotations.Nullable()
   public final java.lang.String getX();//  getX()
 

compiler/testData/asJava/ultraLightClasses/jvmField.fir.java

@@ -29,6 +29,10 @@ public static final class Companion /* A.Companion*/ {
 }
 
 public abstract interface B /* B*/ {
+  @kotlin.jvm.JvmField()
+  @org.jetbrains.annotations.NotNull()
+  public static final java.util.Collection<?> a;
+
   @org.jetbrains.annotations.NotNull()
   public static final B.Companion Companion;
 

compiler/testData/asJava/ultraLightClasses/objects.fir.java

@@ -1,11 +1,17 @@
 public final class C /* C*/ {
   @kotlin.jvm.JvmStatic()
   @org.jetbrains.annotations.NotNull()
-  public java.lang.String x;
+  public static java.lang.String x;
 
   @org.jetbrains.annotations.NotNull()
   public static final C.Companion Companion;
 
+  @org.jetbrains.annotations.NotNull()
+  public static java.lang.String c1;
+
+  @org.jetbrains.annotations.NotNull()
+  public static java.lang.String c;
+
   @kotlin.jvm.JvmStatic()
   public static final void foo();//  foo()
 
@@ -20,10 +26,6 @@ public final class C /* C*/ {
   }
 
 public static final class Companion /* C.Companion*/ {
-  @kotlin.jvm.JvmStatic()
-  @org.jetbrains.annotations.NotNull()
-  private java.lang.String x;
-
   @kotlin.jvm.JvmStatic()
   @org.jetbrains.annotations.NotNull()
   public final java.lang.String getC(I);//  getC(I)

compiler/testData/asJava/ultraLightClasses/properties.fir.java

@@ -80,6 +80,12 @@ public final class Foo /* Foo*/ {
 
   public java.lang.String internalVarPrivateSet;
 
+  public static final int f1;
+
+  public static final int prop3;
+
+  public static int prop7;
+
   @org.jetbrains.annotations.NotNull()
   protected final java.lang.String getProtectedLateinitVar();//  getProtectedLateinitVar()
 
@@ -191,12 +197,6 @@ public final class Foo /* Foo*/ {
   }
 
 public static final class Companion /* Foo.Companion*/ {
-  private final int f1;
-
-  private final int prop3;
-
-  private int prop7;
-
   private  Companion();//  .ctor()
 
   public final int getF1();//  getF1()