Add FirSymbolProvider::getAllCallableNamesInPackage function

- Also, fix implementation of `getCallableNames` in few cases

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/FirSymbolProvider.kt

@@ -55,6 +55,8 @@ abstract class FirSymbolProvider : FirSessionComponent {
     open fun getNestedClassesNamesInClass(classId: ClassId): Set<Name> = emptySet()
 
     abstract fun getPackage(fqName: FqName): FqName? // TODO: Replace to symbol sometime
+
+    open fun getAllCallableNamesInPackage(): Set<Name> = emptySet()
 }
 
 fun FirSession.getNestedClassifierScope(lookupTag: ConeClassLikeLookupTag): FirScope? =

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirCompositeSymbolProvider.kt

@@ -46,4 +46,8 @@ class FirCompositeSymbolProvider(val providers: List<FirSymbolProvider>) : FirSy
     override fun getNestedClassesNamesInClass(classId: ClassId): Set<Name> {
         return providers.flatMapTo(mutableSetOf()) { it.getNestedClassesNamesInClass(classId) }
     }
+
+    override fun getAllCallableNamesInPackage(): Set<Name> {
+        return providers.flatMapTo(mutableSetOf()) { it.getAllCallableNamesInPackage() }
+    }
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/providers/impl/FirProviderImpl.kt

@@ -76,6 +76,12 @@ class FirProviderImpl(val session: FirSession, val kotlinScopeProvider: KotlinSc
         klass.accept(FirRecorder, state to owner.file)
     }
 
+    override fun getAllCallableNamesInPackage(): Set<Name> {
+        return state.callableMap.keys.asSequence()
+            .filter { it.className == null }
+            .mapTo(mutableSetOf()) { it.callableName }
+    }
+
     private val FirAnnotatedDeclaration.file: FirFile
         get() = when (this) {
             is FirFile -> this

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirLocalScope.kt

@@ -71,5 +71,5 @@ class FirLocalScope private constructor(
 
     override fun mayContainName(name: Name) = properties.containsKey(name) || functions[name].isNotEmpty() || classes.containsKey(name)
 
-    override fun getCallableNames(): Set<Name> = properties.keys + functions.keys + classes.keys
+    override fun getCallableNames(): Set<Name> = properties.keys + functions.keys
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirPackageMemberScope.kt

@@ -56,4 +56,8 @@ class FirPackageMemberScope(val fqName: FqName, val session: FirSession) : FirSc
             }
         }
     }
+
+    override fun getCallableNames(): Set<Name> {
+        return symbolProvider.getAllCallableNamesInPackage()
+    }
 }

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirStaticScope.kt

@@ -35,4 +35,8 @@ class FirStaticScope(private val delegateScope: FirScope) : FirScope() {
             }
         }
     }
+
+    override fun getCallableNames(): Set<Name> {
+        return delegateScope.getCallableNames()
+    }
 }

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/FirIdeProvider.kt

@@ -166,6 +166,11 @@ internal class FirIdeProvider(
         // TODO: check that this implementation is correct
         cacheProvider.recordGeneratedMember(owner, klass)
     }
+
+    // TODO this should be reworked because [FirIdeProvider] should not have such method
+    override fun getAllCallableNamesInPackage(): Set<Name> {
+        return cacheProvider.getAllCallableNamesInPackage()
+    }
 }
 
 internal val FirSession.firIdeProvider: FirIdeProvider by FirSession.sessionComponentAccessor()