Enable unused-function warning for runtime (#4628)

kotlin-native/build-tools/src/main/kotlin/org/jetbrains/kotlin/bitcode/CompileToBitcode.kt

@@ -71,7 +71,6 @@ open class CompileToBitcode @Inject constructor(
                     listOfNotNull("-std=c++14", "-Werror", "-O2",
                             "-Wall", "-Wextra",
                             "-Wno-unused-parameter",  // False positives with polymorphic functions.
-                            "-Wno-unused-function",  // TODO: Enable this warning when we have C++ runtime tests.
                             "-fPIC".takeIf { !HostManager().targetByName(target).isMINGW })
             }
             return commonFlags + languageFlags + compilerArgs

kotlin-native/common/src/hash/cpp/City.cpp

@@ -57,11 +57,6 @@ uint32_t Fetch32(const char *p) {
   return uint32_in_expected_order(UNALIGNED_LOAD32(p));
 }
 
-uint32_t Rotate32(uint32_t val, int shift) {
-  // Avoid shifting by 32: doing so yields an undefined result.
-  return shift == 0 ? val : ((val >> shift) | (val << (32 - shift)));
-}
-
 // Bitwise right rotate.  Normally this will compile to a single
 // instruction, especially if the shift is a manifest constant.
 uint64_t Rotate(uint64_t val, int shift) {

kotlin-native/common/src/hash/cpp/Names.cpp

@@ -23,18 +23,6 @@
 
 namespace {
 
-constexpr uint32_t PrintableHexSize(uint32_t input_length) {
-  return input_length * 2;
-}
-
-void PrintableHex(const uint8_t* data, uint32_t data_length, char* hex) {
-  static const char* hex_digits = "0123456789ABCDEF";
-  for (uint32_t i = 0; i < data_length; ++i) {
-    *hex++ = hex_digits[(*data >> 4) & 0xf];
-    *hex++ = hex_digits[(*data++) & 0xf];
-  }
-}
-
 constexpr uint32_t PrintableBase64Size(uint32_t input_length) {
   return ((input_length + 2) / 3 * 4) + 1;
 }

kotlin-native/runtime/src/legacymm/cpp/Memory.cpp

@@ -798,7 +798,6 @@ namespace {
 void freeContainer(ContainerHeader* header) NO_INLINE;
 #if USE_GC
 void garbageCollect(MemoryState* state, bool force) NO_INLINE;
-void cyclicGarbageCollect() NO_INLINE;
 void rememberNewContainer(ContainerHeader* container);
 #endif  // USE_GC
 
@@ -1017,10 +1016,6 @@ inline FrameOverlay* asFrameOverlay(ObjHeader** slot) {
   return reinterpret_cast<FrameOverlay*>(slot);
 }
 
-inline bool isRefCounted(KConstRef object) {
-  return isFreeable(containerFor(object));
-}
-
 inline void lock(KInt* spinlock) {
   while (compareAndSwap(spinlock, 0, 1) != 0) {}
 }
@@ -1698,6 +1693,7 @@ void collectWhite(MemoryState* state, ContainerHeader* start) {
 }
 #endif
 
+#if COLLECT_STATISTIC
 inline bool needAtomicAccess(ContainerHeader* container) {
   return container->shareable();
 }
@@ -1707,6 +1703,7 @@ inline bool canBeCyclic(ContainerHeader* container) {
   if (container->color() == CONTAINER_TAG_GC_GREEN) return false;
   return true;
 }
+#endif
 
 inline void addHeapRef(ContainerHeader* container) {
   MEMORY_LOG("AddHeapRef %p: rc=%d\n", container, container->refCount())
@@ -1774,6 +1771,11 @@ inline void releaseHeapRef(const ObjHeader* header) {
     releaseHeapRef<Strict, CanCollect>(const_cast<ContainerHeader*>(container));
 }
 
+
+// TODO: Consider removing this unused stuff.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunused-function"
+
 // We use first slot as place to store frame-local arena container.
 // TODO: create ArenaContainer object on the stack, so that we don't
 // do two allocations per frame (ArenaContainer + actual container).
@@ -1800,6 +1802,8 @@ inline size_t containerSize(const ContainerHeader* container) {
   return result;
 }
 
+#pragma clang diagnostic pop
+
 #if USE_GC
 void incrementStack(MemoryState* state) {
   FrameOverlay* frame = currentFrame;

kotlin-native/runtime/src/main/cpp/Exceptions.cpp

@@ -107,11 +107,13 @@ _Unwind_Reason_Code unwindCallback(
 
 THREAD_LOCAL_VARIABLE bool disallowSourceInfo = false;
 
+#if !OMIT_BACKTRACE && !USE_GCC_UNWIND
 SourceInfo getSourceInfo(KConstRef stackTrace, int index) {
   return disallowSourceInfo
       ? SourceInfo { .fileName = nullptr, .lineNumber = -1, .column = -1 }
       : Kotlin_getSourceInfo(*PrimitiveArrayAddressOfElementAt<KNativePtr>(stackTrace->array(), index));
 }
+#endif
 
 }  // namespace
 

kotlin-native/runtime/src/main/cpp/ObjCExport.mm

@@ -124,7 +124,6 @@ extern "C" OBJ_GETTER(Kotlin_ObjCExport_AllocInstanceWithAssociatedObject,
 }
 
 static Class getOrCreateClass(const TypeInfo* typeInfo);
-static void initializeClass(Class clazz);
 
 extern "C" id objc_retainAutoreleaseReturnValue(id self);
 
@@ -768,16 +767,6 @@ static KStdVector<const TypeInfo*> getProtocolsAsInterfaces(Class clazz) {
   return result;
 }
 
-static const TypeInfo* getMostSpecificKotlinClass(const TypeInfo* typeInfo) {
-  const TypeInfo* result = typeInfo;
-  while (getTypeAdapter(result) == nullptr) {
-    result = result->superType_;
-    RuntimeAssert(result != nullptr, "");
-  }
-
-  return result;
-}
-
 static int getVtableSize(const TypeInfo* typeInfo) {
   for (const TypeInfo* current = typeInfo; current != nullptr; current = current->superType_) {
     auto typeAdapter = getTypeAdapter(current);