FIR IDE: allow get overriding symbols of members in anonymous object

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirSymbolDeclarationOverridesProvider.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirIntersectionOverridePropertySymb
 import org.jetbrains.kotlin.analysis.low.level.api.fir.lazy.resolve.ResolveType
 import org.jetbrains.kotlin.analysis.api.components.KtSymbolDeclarationOverridesProvider
 import org.jetbrains.kotlin.analysis.api.fir.KtFirAnalysisSession
+import org.jetbrains.kotlin.analysis.api.fir.symbols.KtFirAnonymousObjectSymbol
 import org.jetbrains.kotlin.analysis.api.fir.symbols.KtFirNamedClassOrObjectSymbol
 import org.jetbrains.kotlin.analysis.api.fir.symbols.KtFirSymbol
 import org.jetbrains.kotlin.analysis.api.symbols.KtCallableSymbol
@@ -97,13 +98,15 @@ internal class KtFirSymbolDeclarationOverridesProvider(
         val containingDeclaration = with(analysisSession) {
             (callableSymbol as? KtCallableSymbol)?.originalContainingClassForOverride
         } ?: return
-        check(containingDeclaration is KtFirNamedClassOrObjectSymbol)
-
-        processOverrides(containingDeclaration, callableSymbol, process)
+        when (containingDeclaration) {
+            is KtFirNamedClassOrObjectSymbol -> processOverrides(containingDeclaration, callableSymbol, process)
+            is KtFirAnonymousObjectSymbol -> processOverrides(containingDeclaration, callableSymbol, process)
+            else -> throw IllegalStateException("Expected $containingDeclaration to be a KtFirNamedClassOrObjectSymbol or KtFirAnonymousObjectSymbol")
+        }
     }
 
     private inline fun processOverrides(
-        containingDeclaration: KtFirNamedClassOrObjectSymbol,
+        containingDeclaration: KtFirSymbol<FirClass>,
         callableSymbol: KtFirSymbol<*>,
         crossinline process: (FirTypeScope, FirDeclaration) -> Unit
     ) {

analysis/analysis-api-fir/tests/org/jetbrains/kotlin/analysis/api/fir/components/OverriddenDeclarationProviderTestGenerated.java

@@ -24,6 +24,12 @@ public class OverriddenDeclarationProviderTestGenerated extends AbstractOverridd
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/components/overridenDeclarations"), Pattern.compile("^(.+)\\.kt$"), null, true);
     }
 
+    @Test
+    @TestMetadata("inAnonymousClass.kt")
+    public void testInAnonymousClass() throws Exception {
+        runTest("analysis/analysis-api/testData/components/overridenDeclarations/inAnonymousClass.kt");
+    }
+
     @Test
     @TestMetadata("inLocalClass.kt")
     public void testInLocalClass() throws Exception {

analysis/analysis-api/testData/components/overridenDeclarations/inAnonymousClass.kt

@@ -0,0 +1,9 @@
+fun foo() {
+    open class A {
+        open fun foo() {}
+    }
+
+    object : A() {
+        override fun fo<caret>o() {}
+    }
+}

analysis/analysis-api/testData/components/overridenDeclarations/inAnonymousClass.txt

@@ -0,0 +1,4 @@
+ALL:
+  foo.A.foo(): Unit
+DIRECT:
+  foo.A.foo(): Unit