FIR LC: populate fields from companion in interface

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

@@ -12,10 +12,12 @@ import com.intellij.psi.search.SearchScope
 import com.intellij.psi.stubs.IStubElementType
 import com.intellij.psi.stubs.StubElement
 import org.jetbrains.annotations.NonNls
+import org.jetbrains.kotlin.analysis.api.symbols.KtKotlinPropertySymbol
 import org.jetbrains.kotlin.asJava.classes.getOutermostClassOrObject
 import org.jetbrains.kotlin.asJava.classes.lazyPub
 import org.jetbrains.kotlin.asJava.elements.KtLightField
 import org.jetbrains.kotlin.analysis.api.symbols.KtNamedClassOrObjectSymbol
+import org.jetbrains.kotlin.analysis.api.symbols.KtPropertySymbol
 import org.jetbrains.kotlin.analysis.api.symbols.markers.KtSymbolKind
 import org.jetbrains.kotlin.light.classes.symbol.classes.createInnerClasses
 import org.jetbrains.kotlin.light.classes.symbol.classes.getOrCreateFirLightClass
@@ -94,6 +96,27 @@ internal abstract class FirLightClassForClassOrObjectSymbol(
         }
     }
 
+    protected fun addFieldsFromCompanionIfNeeded(result: MutableList<KtLightField>) {
+        classOrObjectSymbol.companionObject?.run {
+            analyzeWithSymbolAsContext(this) {
+                getDeclaredMemberScope().getCallableSymbols()
+                    .filterIsInstance<KtPropertySymbol>()
+                    .filter { it.hasJvmFieldAnnotation() || it.hasJvmStaticAnnotation() || it is KtKotlinPropertySymbol && it.isConst }
+                    .mapTo(result) {
+                        FirLightFieldForPropertySymbol(
+                            propertySymbol = it,
+                            fieldName = it.name.asString(),
+                            containingClass = this@FirLightClassForClassOrObjectSymbol,
+                            lightMemberOrigin = null,
+                            isTopLevel = false,
+                            forceStatic = !it.hasJvmStaticAnnotation(),
+                            takePropertyVisibility = 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

@@ -241,27 +241,6 @@ internal open class FirLightClassForSymbol(
         result
     }
 
-    private fun addFieldsFromCompanionIfNeeded(result: MutableList<KtLightField>) {
-        classOrObjectSymbol.companionObject?.run {
-            analyzeWithSymbolAsContext(this) {
-                getDeclaredMemberScope().getCallableSymbols()
-                    .filterIsInstance<KtPropertySymbol>()
-                    .filter { it.hasJvmFieldAnnotation() || it.hasJvmStaticAnnotation() || it is KtKotlinPropertySymbol && it.isConst }
-                    .mapTo(result) {
-                        FirLightFieldForPropertySymbol(
-                            propertySymbol = it,
-                            fieldName = it.name.asString(),
-                            containingClass = this@FirLightClassForSymbol,
-                            lightMemberOrigin = null,
-                            isTopLevel = false,
-                            forceStatic = !it.hasJvmStaticAnnotation(),
-                            takePropertyVisibility = true
-                        )
-                    }
-            }
-        }
-    }
-
     private fun addPropertyBackingFields(result: MutableList<KtLightField>) {
         analyzeWithSymbolAsContext(classOrObjectSymbol) {
             val propertySymbols = classOrObjectSymbol.getDeclaredMemberScope().getCallableSymbols()

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

@@ -31,6 +31,7 @@ internal open class FirLightInterfaceClassSymbol(
     private val _ownFields: List<KtLightField> by lazyPub {
         mutableListOf<KtLightField>().also {
             addCompanionObjectFieldIfNeeded(it)
+            addFieldsFromCompanionIfNeeded(it)
         }
     }
 

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

@@ -2,6 +2,9 @@ public abstract interface TraitClassObjectField /* TraitClassObjectField*/ {
   @org.jetbrains.annotations.NotNull()
   public static final TraitClassObjectField.Companion Companion;
 
+  @org.jetbrains.annotations.Nullable()
+  public static final java.lang.String x = "" /* initializer type: java.lang.String */;
+
 
 public static final class Companion /* TraitClassObjectField.Companion*/ {
   @org.jetbrains.annotations.Nullable()