diff options
Diffstat (limited to 'runtime/class_linker.cc')
| -rw-r--r-- | runtime/class_linker.cc | 934 |
1 files changed, 647 insertions, 287 deletions
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc index 514d3cc844..2dd2a83888 100644 --- a/runtime/class_linker.cc +++ b/runtime/class_linker.cc @@ -153,7 +153,7 @@ static void HandleEarlierVerifyError(Thread* self, ClassLinker* class_linker, mi self->AssertPendingException(); } -void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c) { +void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c, bool wrap_in_no_class_def) { // The class failed to initialize on a previous attempt, so we want to throw // a NoClassDefFoundError (v2 2.17.5). The exception to this rule is if we // failed in verification, in which case v2 5.4.1 says we need to re-throw @@ -178,10 +178,15 @@ void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c) { self->SetException(pre_allocated); } else { if (c->GetVerifyError() != nullptr) { + // Rethrow stored error. HandleEarlierVerifyError(self, this, c); - } else { - self->ThrowNewException("Ljava/lang/NoClassDefFoundError;", - PrettyDescriptor(c).c_str()); + } + if (c->GetVerifyError() == nullptr || wrap_in_no_class_def) { + // If there isn't a recorded earlier error, or this is a repeat throw from initialization, + // the top-level exception must be a NoClassDefFoundError. The potentially already pending + // exception will be a cause. + self->ThrowNewWrappedException("Ljava/lang/NoClassDefFoundError;", + PrettyDescriptor(c).c_str()); } } } @@ -298,7 +303,7 @@ static void ShuffleForward(size_t* current_field_idx, ClassLinker::ClassLinker(InternTable* intern_table) // dex_lock_ is recursive as it may be used in stack dumping. : dex_lock_("ClassLinker dex lock", kDefaultMutexLevel), - dex_cache_image_class_lookup_required_(false), + dex_cache_boot_image_class_lookup_required_(false), failed_dex_cache_class_lookups_(0), class_roots_(nullptr), array_iftable_(nullptr), @@ -317,7 +322,8 @@ ClassLinker::ClassLinker(InternTable* intern_table) std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot<mirror::Class>(nullptr)); } -void ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path) { +bool ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> boot_class_path, + std::string* error_msg) { VLOG(startup) << "ClassLinker::Init"; Thread* const self = Thread::Current(); @@ -363,10 +369,12 @@ void ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> b mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self); java_lang_Object->SetObjectSize(sizeof(mirror::Object)); - runtime->SetSentinel(heap->AllocObject<true>(self, - java_lang_Object.Get(), - java_lang_Object->GetObjectSize(), - VoidFunctor())); + // Allocate in non-movable so that it's possible to check if a JNI weak global ref has been + // cleared without triggering the read barrier and unintentionally mark the sentinel alive. + runtime->SetSentinel(heap->AllocNonMovableObject<true>(self, + java_lang_Object.Get(), + java_lang_Object->GetObjectSize(), + VoidFunctor())); // Object[] next to hold class roots. Handle<mirror::Class> object_array_class(hs.NewHandle( @@ -470,9 +478,15 @@ void ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> b // Setup boot_class_path_ and register class_path now that we can use AllocObjectArray to create // DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses // these roots. - CHECK_NE(0U, boot_class_path.size()); + if (boot_class_path.empty()) { + *error_msg = "Boot classpath is empty."; + return false; + } for (auto& dex_file : boot_class_path) { - CHECK(dex_file.get() != nullptr); + if (dex_file.get() == nullptr) { + *error_msg = "Null dex file."; + return false; + } AppendToBootClassPath(self, *dex_file); opened_dex_files_.push_back(std::move(dex_file)); } @@ -653,6 +667,8 @@ void ClassLinker::InitWithoutImage(std::vector<std::unique_ptr<const DexFile>> b FinishInit(self); VLOG(startup) << "ClassLinker::InitFromCompiler exiting"; + + return true; } void ClassLinker::FinishInit(Thread* self) { @@ -789,7 +805,7 @@ static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_ CHECK_EQ(field.GetDeclaringClass(), klass); } auto* runtime = Runtime::Current(); - auto* image_space = runtime->GetHeap()->GetImageSpace(); + auto* image_space = runtime->GetHeap()->GetBootImageSpace(); auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize(); for (auto& m : klass->GetDirectMethods(pointer_size)) { SanityCheckArtMethod(&m, klass, image_space); @@ -843,17 +859,17 @@ class SetInterpreterEntrypointArtMethodVisitor : public ArtMethodVisitor { DISALLOW_COPY_AND_ASSIGN(SetInterpreterEntrypointArtMethodVisitor); }; -void ClassLinker::InitFromImage() { +bool ClassLinker::InitFromImage(std::string* error_msg) { VLOG(startup) << "ClassLinker::InitFromImage entering"; CHECK(!init_done_); Runtime* const runtime = Runtime::Current(); Thread* const self = Thread::Current(); gc::Heap* const heap = runtime->GetHeap(); - gc::space::ImageSpace* const space = heap->GetImageSpace(); + gc::space::ImageSpace* const space = heap->GetBootImageSpace(); CHECK(space != nullptr); image_pointer_size_ = space->GetImageHeader().GetPointerSize(); - dex_cache_image_class_lookup_required_ = true; + dex_cache_boot_image_class_lookup_required_ = true; const OatFile* oat_file = runtime->GetOatFileManager().RegisterImageOatFile(space); DCHECK(oat_file != nullptr); CHECK_EQ(oat_file->GetOatHeader().GetImageFileLocationOatChecksum(), 0U); @@ -881,27 +897,39 @@ void ClassLinker::InitFromImage() { mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); java_lang_Object->SetObjectSize(sizeof(mirror::Object)); - Runtime::Current()->SetSentinel(heap->AllocObject<true>(self, - java_lang_Object, - java_lang_Object->GetObjectSize(), - VoidFunctor())); - - CHECK_EQ(oat_file->GetOatHeader().GetDexFileCount(), - static_cast<uint32_t>(dex_caches->GetLength())); + // Allocate in non-movable so that it's possible to check if a JNI weak global ref has been + // cleared without triggering the read barrier and unintentionally mark the sentinel alive. + runtime->SetSentinel(heap->AllocNonMovableObject<true>(self, + java_lang_Object, + java_lang_Object->GetObjectSize(), + VoidFunctor())); + + if (oat_file->GetOatHeader().GetDexFileCount() != + static_cast<uint32_t>(dex_caches->GetLength())) { + *error_msg = "Dex cache count and dex file count mismatch while trying to initialize from " + "image"; + return false; + } for (int32_t i = 0; i < dex_caches->GetLength(); i++) { StackHandleScope<1> hs2(self); Handle<mirror::DexCache> dex_cache(hs2.NewHandle(dex_caches->Get(i))); const std::string& dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8()); const OatFile::OatDexFile* oat_dex_file = oat_file->GetOatDexFile(dex_file_location.c_str(), nullptr); - CHECK(oat_dex_file != nullptr) << oat_file->GetLocation() << " " << dex_file_location; - std::string error_msg; - std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&error_msg); + if (oat_dex_file == nullptr) { + *error_msg = StringPrintf("Failed finding oat dex file for %s %s", + oat_file->GetLocation().c_str(), + dex_file_location.c_str()); + return false; + } + std::string inner_error_msg; + std::unique_ptr<const DexFile> dex_file = oat_dex_file->OpenDexFile(&inner_error_msg); if (dex_file == nullptr) { - LOG(FATAL) << "Failed to open dex file " << dex_file_location - << " from within oat file " << oat_file->GetLocation() - << " error '" << error_msg << "'"; - UNREACHABLE(); + *error_msg = StringPrintf("Failed to open dex file %s from within oat file %s error '%s'", + dex_file_location.c_str(), + oat_file->GetLocation().c_str(), + inner_error_msg.c_str()); + return false; } if (kSanityCheckObjects) { @@ -911,13 +939,22 @@ void ClassLinker::InitFromImage() { space); } - CHECK_EQ(dex_file->GetLocationChecksum(), oat_dex_file->GetDexFileLocationChecksum()); + if (dex_file->GetLocationChecksum() != oat_dex_file->GetDexFileLocationChecksum()) { + *error_msg = StringPrintf("Checksums do not match for %s: %x vs %x", + dex_file_location.c_str(), + dex_file->GetLocationChecksum(), + oat_dex_file->GetDexFileLocationChecksum()); + return false; + } AppendToBootClassPath(*dex_file.get(), dex_cache); opened_dex_files_.push_back(std::move(dex_file)); } - CHECK(ValidPointerSize(image_pointer_size_)) << image_pointer_size_; + if (!ValidPointerSize(image_pointer_size_)) { + *error_msg = StringPrintf("Invalid image pointer size: %zu", image_pointer_size_); + return false; + } // Set classes on AbstractMethod early so that IsMethod tests can be performed during the live // bitmap walk. @@ -925,7 +962,12 @@ void ClassLinker::InitFromImage() { // Only the Aot compiler supports having an image with a different pointer size than the // runtime. This happens on the host for compile 32 bit tests since we use a 64 bit libart // compiler. We may also use 32 bit dex2oat on a system with 64 bit apps. - CHECK_EQ(image_pointer_size_, sizeof(void*)); + if (image_pointer_size_ != sizeof(void*)) { + *error_msg = StringPrintf("Runtime must use current image pointer size: %zu vs %zu", + image_pointer_size_ , + sizeof(void*)); + return false; + } } if (kSanityCheckObjects) { @@ -978,6 +1020,8 @@ void ClassLinker::InitFromImage() { FinishInit(self); VLOG(startup) << "ClassLinker::InitFromImage exiting"; + + return true; } bool ClassLinker::ClassInClassTable(mirror::Class* klass) { @@ -1081,8 +1125,8 @@ void ClassLinker::VisitClassesInternal(ClassVisitor* visitor) { } void ClassLinker::VisitClasses(ClassVisitor* visitor) { - if (dex_cache_image_class_lookup_required_) { - MoveImageClassesToClassTable(); + if (dex_cache_boot_image_class_lookup_required_) { + AddBootImageClassesToClassTable(); } Thread* const self = Thread::Current(); ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); @@ -1853,7 +1897,7 @@ const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* // Special case to get oat code without overwriting a trampoline. const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { - CHECK(!method->IsAbstract()) << PrettyMethod(method); + CHECK(method->IsInvokable()) << PrettyMethod(method); if (method->IsProxyMethod()) { return GetQuickProxyInvokeHandler(); } @@ -1873,7 +1917,7 @@ const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { } const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) { - if (method->IsNative() || method->IsAbstract() || method->IsProxyMethod()) { + if (method->IsNative() || !method->IsInvokable() || method->IsProxyMethod()) { return nullptr; } bool found; @@ -1968,6 +2012,13 @@ void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) { // Ignore virtual methods on the iterator. } +void ClassLinker::EnsureThrowsInvocationError(ArtMethod* method) { + DCHECK(method != nullptr); + DCHECK(!method->IsInvokable()); + method->SetEntryPointFromQuickCompiledCodePtrSize(quick_to_interpreter_bridge_trampoline_, + image_pointer_size_); +} + void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class, uint32_t class_def_method_index) { Runtime* const runtime = Runtime::Current(); @@ -1987,8 +2038,8 @@ void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class // Install entry point from interpreter. bool enter_interpreter = NeedsInterpreter(method, method->GetEntryPointFromQuickCompiledCode()); - if (method->IsAbstract()) { - method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); + if (!method->IsInvokable()) { + EnsureThrowsInvocationError(method); return; } @@ -2312,17 +2363,22 @@ void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file, // Clean up pass to remove null dex caches. // Null dex caches can occur due to class unloading and we are lazily removing null entries. JavaVMExt* const vm = self->GetJniEnv()->vm; - for (auto it = dex_caches_.begin(); it != dex_caches_.end();) { - mirror::Object* dex_cache_root = self->DecodeJObject(*it); - if (dex_cache_root == nullptr) { - vm->DeleteWeakGlobalRef(self, *it); + for (auto it = dex_caches_.begin(); it != dex_caches_.end(); ) { + DexCacheData data = *it; + if (self->IsJWeakCleared(data.weak_root)) { + vm->DeleteWeakGlobalRef(self, data.weak_root); it = dex_caches_.erase(it); } else { ++it; } } - dex_caches_.push_back(vm->AddWeakGlobalRef(self, dex_cache.Get())); + jweak dex_cache_jweak = vm->AddWeakGlobalRef(self, dex_cache.Get()); dex_cache->SetDexFile(&dex_file); + DexCacheData data; + data.weak_root = dex_cache_jweak; + data.dex_file = dex_cache->GetDexFile(); + data.resolved_types = dex_cache->GetResolvedTypes(); + dex_caches_.push_back(data); } mirror::DexCache* ClassLinker::RegisterDexFile(const DexFile& dex_file, LinearAlloc* linear_alloc) { @@ -2369,10 +2425,16 @@ mirror::DexCache* ClassLinker::FindDexCacheLocked(Thread* self, const DexFile& dex_file, bool allow_failure) { // Search assuming unique-ness of dex file. - for (jweak weak_root : dex_caches_) { - mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root)); - if (dex_cache != nullptr && dex_cache->GetDexFile() == &dex_file) { - return dex_cache; + for (const DexCacheData& data : dex_caches_) { + // Avoid decoding (and read barriers) other unrelated dex caches. + if (data.dex_file == &dex_file) { + mirror::DexCache* dex_cache = + down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root)); + if (dex_cache != nullptr) { + return dex_cache; + } else { + break; + } } } if (allow_failure) { @@ -2380,8 +2442,8 @@ mirror::DexCache* ClassLinker::FindDexCacheLocked(Thread* self, } std::string location(dex_file.GetLocation()); // Failure, dump diagnostic and abort. - for (jobject weak_root : dex_caches_) { - mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root)); + for (const DexCacheData& data : dex_caches_) { + mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(data.weak_root)); if (dex_cache != nullptr) { LOG(ERROR) << "Registered dex file " << dex_cache->GetDexFile()->GetLocation(); } @@ -2393,10 +2455,13 @@ mirror::DexCache* ClassLinker::FindDexCacheLocked(Thread* self, void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) { Thread* const self = Thread::Current(); ReaderMutexLock mu(self, dex_lock_); - for (jobject weak_root : dex_caches_) { - mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root)); - if (dex_cache != nullptr) { - dex_cache->Fixup(resolution_method, image_pointer_size_); + for (const DexCacheData& data : dex_caches_) { + if (!self->IsJWeakCleared(data.weak_root)) { + mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>( + self->DecodeJObject(data.weak_root)); + if (dex_cache != nullptr) { + dex_cache->Fixup(resolution_method, image_pointer_size_); + } } } } @@ -2631,11 +2696,13 @@ mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* k if (existing != nullptr) { return existing; } - if (kIsDebugBuild && !klass->IsTemp() && class_loader == nullptr && - dex_cache_image_class_lookup_required_) { + if (kIsDebugBuild && + !klass->IsTemp() && + class_loader == nullptr && + dex_cache_boot_image_class_lookup_required_) { // Check a class loaded with the system class loader matches one in the image if the class // is in the image. - existing = LookupClassFromImage(descriptor); + existing = LookupClassFromBootImage(descriptor); if (existing != nullptr) { CHECK_EQ(klass, existing); } @@ -2679,11 +2746,11 @@ mirror::Class* ClassLinker::LookupClass(Thread* self, } } } - if (class_loader != nullptr || !dex_cache_image_class_lookup_required_) { + if (class_loader != nullptr || !dex_cache_boot_image_class_lookup_required_) { return nullptr; } // Lookup failed but need to search dex_caches_. - mirror::Class* result = LookupClassFromImage(descriptor); + mirror::Class* result = LookupClassFromBootImage(descriptor); if (result != nullptr) { result = InsertClass(descriptor, result, hash); } else { @@ -2692,37 +2759,43 @@ mirror::Class* ClassLinker::LookupClass(Thread* self, // classes into the class table. constexpr uint32_t kMaxFailedDexCacheLookups = 1000; if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) { - MoveImageClassesToClassTable(); + AddBootImageClassesToClassTable(); } } return result; } -static mirror::ObjectArray<mirror::DexCache>* GetImageDexCaches() +static mirror::ObjectArray<mirror::DexCache>* GetImageDexCaches(gc::space::ImageSpace* image_space) SHARED_REQUIRES(Locks::mutator_lock_) { - gc::space::ImageSpace* image = Runtime::Current()->GetHeap()->GetImageSpace(); - CHECK(image != nullptr); - mirror::Object* root = image->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); + CHECK(image_space != nullptr); + mirror::Object* root = image_space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); + DCHECK(root != nullptr); return root->AsObjectArray<mirror::DexCache>(); } -void ClassLinker::MoveImageClassesToClassTable() { +void ClassLinker::AddBootImageClassesToClassTable() { + if (dex_cache_boot_image_class_lookup_required_) { + AddImageClassesToClassTable(Runtime::Current()->GetHeap()->GetBootImageSpace(), + /*class_loader*/nullptr); + dex_cache_boot_image_class_lookup_required_ = false; + } +} + +void ClassLinker::AddImageClassesToClassTable(gc::space::ImageSpace* image_space, + mirror::ClassLoader* class_loader) { Thread* self = Thread::Current(); WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); - if (!dex_cache_image_class_lookup_required_) { - return; // All dex cache classes are already in the class table. - } ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table"); - mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); + mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(image_space); std::string temp; - ClassTable* const class_table = InsertClassTableForClassLoader(nullptr); + ClassTable* const class_table = InsertClassTableForClassLoader(class_loader); for (int32_t i = 0; i < dex_caches->GetLength(); i++) { mirror::DexCache* dex_cache = dex_caches->Get(i); GcRoot<mirror::Class>* types = dex_cache->GetResolvedTypes(); for (int32_t j = 0, num_types = dex_cache->NumResolvedTypes(); j < num_types; j++) { mirror::Class* klass = types[j].Read(); if (klass != nullptr) { - DCHECK(klass->GetClassLoader() == nullptr); + DCHECK_EQ(klass->GetClassLoader(), class_loader); const char* descriptor = klass->GetDescriptor(&temp); size_t hash = ComputeModifiedUtf8Hash(descriptor); mirror::Class* existing = class_table->Lookup(descriptor, hash); @@ -2738,7 +2811,6 @@ void ClassLinker::MoveImageClassesToClassTable() { } } } - dex_cache_image_class_lookup_required_ = false; } class MoveClassTableToPreZygoteVisitor : public ClassLoaderVisitor { @@ -2762,9 +2834,10 @@ void ClassLinker::MoveClassTableToPreZygote() { VisitClassLoaders(&visitor); } -mirror::Class* ClassLinker::LookupClassFromImage(const char* descriptor) { +mirror::Class* ClassLinker::LookupClassFromBootImage(const char* descriptor) { ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup"); - mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches(); + mirror::ObjectArray<mirror::DexCache>* dex_caches = GetImageDexCaches( + Runtime::Current()->GetHeap()->GetBootImageSpace()); for (int32_t i = 0; i < dex_caches->GetLength(); ++i) { mirror::DexCache* dex_cache = dex_caches->Get(i); const DexFile* dex_file = dex_cache->GetDexFile(); @@ -2806,8 +2879,8 @@ class LookupClassesVisitor : public ClassLoaderVisitor { void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Class*>& result) { result.clear(); - if (dex_cache_image_class_lookup_required_) { - MoveImageClassesToClassTable(); + if (dex_cache_boot_image_class_lookup_required_) { + AddBootImageClassesToClassTable(); } Thread* const self = Thread::Current(); ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); @@ -2820,6 +2893,48 @@ void ClassLinker::LookupClasses(const char* descriptor, std::vector<mirror::Clas VisitClassLoaders(&visitor); } +bool ClassLinker::AttemptSupertypeVerification(Thread* self, + Handle<mirror::Class> klass, + Handle<mirror::Class> supertype) { + DCHECK(self != nullptr); + DCHECK(klass.Get() != nullptr); + DCHECK(supertype.Get() != nullptr); + + StackHandleScope<1> hs(self); + // Acquire lock to prevent races on verifying the super class. + ObjectLock<mirror::Class> super_lock(self, supertype); + + if (!supertype->IsVerified() && !supertype->IsErroneous()) { + VerifyClass(self, supertype); + } + if (supertype->IsCompileTimeVerified()) { + // Either we are verified or we soft failed and need to retry at runtime. + return true; + } + // If we got this far then we have a hard failure. + std::string error_msg = + StringPrintf("Rejecting class %s that attempts to sub-type erroneous class %s", + PrettyDescriptor(klass.Get()).c_str(), + PrettyDescriptor(supertype.Get()).c_str()); + LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); + Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); + if (cause.Get() != nullptr) { + // Set during VerifyClass call (if at all). + self->ClearException(); + } + // Change into a verify error. + ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); + if (cause.Get() != nullptr) { + self->GetException()->SetCause(cause.Get()); + } + ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); + if (Runtime::Current()->IsAotCompiler()) { + Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); + } + mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); + return false; +} + void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { // TODO: assert that the monitor on the Class is held ObjectLock<mirror::Class> lock(self, klass); @@ -2870,56 +2985,70 @@ void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { // Verify super class. StackHandleScope<2> hs(self); - Handle<mirror::Class> super(hs.NewHandle(klass->GetSuperClass())); - if (super.Get() != nullptr) { - // Acquire lock to prevent races on verifying the super class. - ObjectLock<mirror::Class> super_lock(self, super); - - if (!super->IsVerified() && !super->IsErroneous()) { - VerifyClass(self, super); - } - if (!super->IsCompileTimeVerified()) { - std::string error_msg( - StringPrintf("Rejecting class %s that attempts to sub-class erroneous class %s", - PrettyDescriptor(klass.Get()).c_str(), - PrettyDescriptor(super.Get()).c_str())); - LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); - Handle<mirror::Throwable> cause(hs.NewHandle(self->GetException())); - if (cause.Get() != nullptr) { - self->ClearException(); - } - ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); - if (cause.Get() != nullptr) { - self->GetException()->SetCause(cause.Get()); - } - ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); - if (Runtime::Current()->IsAotCompiler()) { - Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); + MutableHandle<mirror::Class> supertype(hs.NewHandle(klass->GetSuperClass())); + // If we have a superclass and we get a hard verification failure we can return immediately. + if (supertype.Get() != nullptr && !AttemptSupertypeVerification(self, klass, supertype)) { + CHECK(self->IsExceptionPending()) << "Verification error should be pending."; + return; + } + + // Verify all default super-interfaces. + // + // (1) Don't bother if the superclass has already had a soft verification failure. + // + // (2) Interfaces shouldn't bother to do this recursive verification because they cannot cause + // recursive initialization by themselves. This is because when an interface is initialized + // directly it must not initialize its superinterfaces. We are allowed to verify regardless + // but choose not to for an optimization. If the interfaces is being verified due to a class + // initialization (which would need all the default interfaces to be verified) the class code + // will trigger the recursive verification anyway. + if ((supertype.Get() == nullptr || supertype->IsVerified()) // See (1) + && !klass->IsInterface()) { // See (2) + int32_t iftable_count = klass->GetIfTableCount(); + MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr)); + // Loop through all interfaces this class has defined. It doesn't matter the order. + for (int32_t i = 0; i < iftable_count; i++) { + iface.Assign(klass->GetIfTable()->GetInterface(i)); + DCHECK(iface.Get() != nullptr); + // We only care if we have default interfaces and can skip if we are already verified... + if (LIKELY(!iface->HasDefaultMethods() || iface->IsVerified())) { + continue; + } else if (UNLIKELY(!AttemptSupertypeVerification(self, klass, iface))) { + // We had a hard failure while verifying this interface. Just return immediately. + CHECK(self->IsExceptionPending()) << "Verification error should be pending."; + return; + } else if (UNLIKELY(!iface->IsVerified())) { + // We softly failed to verify the iface. Stop checking and clean up. + // Put the iface into the supertype handle so we know what caused us to fail. + supertype.Assign(iface.Get()); + break; } - mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); - return; } } + // At this point if verification failed, then supertype is the "first" supertype that failed + // verification (without a specific order). If verification succeeded, then supertype is either + // null or the original superclass of klass and is verified. + DCHECK(supertype.Get() == nullptr || + supertype.Get() == klass->GetSuperClass() || + !supertype->IsVerified()); + // Try to use verification information from the oat file, otherwise do runtime verification. const DexFile& dex_file = *klass->GetDexCache()->GetDexFile(); mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady); bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status); - if (oat_file_class_status == mirror::Class::kStatusError) { - VLOG(class_linker) << "Skipping runtime verification of erroneous class " - << PrettyDescriptor(klass.Get()) << " in " - << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); - ThrowVerifyError(klass.Get(), "Rejecting class %s because it failed compile-time verification", - PrettyDescriptor(klass.Get()).c_str()); - mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); - return; - } + // If the oat file says the class had an error, re-run the verifier. That way we will get a + // precise error message. To ensure a rerun, test: + // oat_file_class_status == mirror::Class::kStatusError => !preverified + DCHECK(!(oat_file_class_status == mirror::Class::kStatusError) || !preverified); + verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure; std::string error_msg; if (!preverified) { verifier_failure = verifier::MethodVerifier::VerifyClass(self, klass.Get(), Runtime::Current()->IsAotCompiler(), + Runtime::Current()->IsAotCompiler(), &error_msg); } if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) { @@ -2932,14 +3061,14 @@ void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { // Make sure all classes referenced by catch blocks are resolved. ResolveClassExceptionHandlerTypes(dex_file, klass); if (verifier_failure == verifier::MethodVerifier::kNoFailure) { - // Even though there were no verifier failures we need to respect whether the super-class - // was verified or requiring runtime reverification. - if (super.Get() == nullptr || super->IsVerified()) { + // Even though there were no verifier failures we need to respect whether the super-class and + // super-default-interfaces were verified or requiring runtime reverification. + if (supertype.Get() == nullptr || supertype->IsVerified()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); } else { - CHECK_EQ(super->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); + CHECK_EQ(supertype->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); - // Pretend a soft failure occured so that we don't consider the class verified below. + // Pretend a soft failure occurred so that we don't consider the class verified below. verifier_failure = verifier::MethodVerifier::kSoftFailure; } } else { @@ -2957,9 +3086,9 @@ void ClassLinker::VerifyClass(Thread* self, Handle<mirror::Class> klass) { } } } else { - LOG(WARNING) << "Verification failed on class " << PrettyDescriptor(klass.Get()) - << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() - << " because: " << error_msg; + VLOG(verifier) << "Verification failed on class " << PrettyDescriptor(klass.Get()) + << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() + << " because: " << error_msg; self->AssertNoPendingException(); ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); @@ -3270,15 +3399,18 @@ ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, ArtMethod Thread* const self = Thread::Current(); ReaderMutexLock mu(self, dex_lock_); // Locate the dex cache of the original interface/Object - for (jobject weak_root : dex_caches_) { - mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>(self->DecodeJObject(weak_root)); - if (dex_cache != nullptr && - proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes(), + for (const DexCacheData& data : dex_caches_) { + if (!self->IsJWeakCleared(data.weak_root) && + proxy_method->HasSameDexCacheResolvedTypes(data.resolved_types, image_pointer_size_)) { - ArtMethod* resolved_method = dex_cache->GetResolvedMethod( - proxy_method->GetDexMethodIndex(), image_pointer_size_); - CHECK(resolved_method != nullptr); - return resolved_method; + mirror::DexCache* dex_cache = down_cast<mirror::DexCache*>( + self->DecodeJObject(data.weak_root)); + if (dex_cache != nullptr) { + ArtMethod* resolved_method = dex_cache->GetResolvedMethod( + proxy_method->GetDexMethodIndex(), image_pointer_size_); + CHECK(resolved_method != nullptr); + return resolved_method; + } } } } @@ -3343,7 +3475,7 @@ void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) cons // Basic sanity CHECK(!prototype->IsFinal()); CHECK(method->IsFinal()); - CHECK(!method->IsAbstract()); + CHECK(method->IsInvokable()); // The proxy method doesn't have its own dex cache or dex file and so it steals those of its // interface prototype. The exception to this are Constructors and the Class of the Proxy itself. @@ -3430,7 +3562,7 @@ bool ClassLinker::InitializeClass(Thread* self, Handle<mirror::Class> klass, // Was the class already found to be erroneous? Done under the lock to match the JLS. if (klass->IsErroneous()) { - ThrowEarlierClassFailure(klass.Get()); + ThrowEarlierClassFailure(klass.Get(), true); VlogClassInitializationFailure(klass); return false; } @@ -4074,10 +4206,10 @@ bool ClassLinker::LinkClass(Thread* self, Runtime::Current()->GetHeap()->WriteBarrierEveryFieldOf(class_loader); } CHECK_EQ(existing, klass.Get()); - if (kIsDebugBuild && class_loader == nullptr && dex_cache_image_class_lookup_required_) { + if (kIsDebugBuild && class_loader == nullptr && dex_cache_boot_image_class_lookup_required_) { // Check a class loaded with the system class loader matches one in the image if the class // is in the image. - mirror::Class* const image_class = LookupClassFromImage(descriptor); + mirror::Class* const image_class = LookupClassFromBootImage(descriptor); if (image_class != nullptr) { CHECK_EQ(klass.Get(), existing) << descriptor; } @@ -4419,7 +4551,7 @@ bool ClassLinker::LinkMethods(Thread* self, // A map from vtable indexes to the method they need to be updated to point to. Used because we // need to have default methods be in the virtuals array of each class but we don't set that up // until LinkInterfaceMethods. - std::unordered_map<size_t, ArtMethod*> default_translations; + std::unordered_map<size_t, ClassLinker::MethodTranslation> default_translations; // Link virtual methods then interface methods. // We set up the interface lookup table first because we need it to determine if we need to update // any vtable entries with new default method implementations. @@ -4552,7 +4684,7 @@ const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits<uint32 bool ClassLinker::LinkVirtualMethods( Thread* self, Handle<mirror::Class> klass, - /*out*/std::unordered_map<size_t, ArtMethod*>* default_translations) { + /*out*/std::unordered_map<size_t, ClassLinker::MethodTranslation>* default_translations) { const size_t num_virtual_methods = klass->NumVirtualMethods(); if (klass->IsInterface()) { // No vtable. @@ -4675,46 +4807,55 @@ bool ClassLinker::LinkVirtualMethods( << " would have incorrectly overridden the package-private method in " << PrettyDescriptor(super_method->GetDeclaringClassDescriptor()); } - } else if (super_method->IsDefault()) { + } else if (super_method->IsOverridableByDefaultMethod()) { // We didn't directly override this method but we might through default methods... // Check for default method update. ArtMethod* default_method = nullptr; - std::string icce_message; - if (!FindDefaultMethodImplementation(self, - super_method, - klass, - /*out*/&default_method, - /*out*/&icce_message)) { - // An error occurred while finding default methods. - // TODO This should actually be thrown when we attempt to invoke this method. - ThrowIncompatibleClassChangeError(klass.Get(), "%s", icce_message.c_str()); - return false; - } - // This should always work because we inherit superclass interfaces. We should either get - // 1) An IncompatibleClassChangeError because of conflicting default method - // implementations. - // 2) The same default method implementation as the superclass. - // 3) A default method that overrides the superclass's. - // Therefore this check should never fail. - CHECK(default_method != nullptr); - if (UNLIKELY(default_method->GetDeclaringClass() != super_method->GetDeclaringClass())) { - // TODO Refactor this add default methods to virtuals here and not in - // LinkInterfaceMethods maybe. - // The problem is default methods might override previously present default-method or - // miranda-method vtable entries from the superclass. Unfortunately we need these to - // be entries in this class's virtuals. We do not give these entries there until - // LinkInterfaceMethods so we pass this map around to let it know which vtable - // entries need to be updated. - // Make a note that vtable entry j must be updated, store what it needs to be updated to. - // We will allocate a virtual method slot in LinkInterfaceMethods and fix it up then. - default_translations->insert({j, default_method}); - VLOG(class_linker) << "Method " << PrettyMethod(super_method) << " overridden by default " - << PrettyMethod(default_method) << " in " << PrettyClass(klass.Get()); - } else { - // They are the same method/no override - // Cannot do direct comparison because we had to copy the ArtMethod object into the - // superclass's vtable. - continue; + switch (FindDefaultMethodImplementation(self, + super_method, + klass, + /*out*/&default_method)) { + case DefaultMethodSearchResult::kDefaultConflict: { + // A conflict was found looking for default methods. Note this (assuming it wasn't + // pre-existing) in the translations map. + if (UNLIKELY(!super_method->IsDefaultConflicting())) { + // Don't generate another conflict method to reduce memory use as an optimization. + default_translations->insert( + {j, ClassLinker::MethodTranslation::CreateConflictingMethod()}); + } + break; + } + case DefaultMethodSearchResult::kAbstractFound: { + // No conflict but method is abstract. + // We note that this vtable entry must be made abstract. + if (UNLIKELY(!super_method->IsAbstract())) { + default_translations->insert( + {j, ClassLinker::MethodTranslation::CreateAbstractMethod()}); + } + break; + } + case DefaultMethodSearchResult::kDefaultFound: { + if (UNLIKELY(super_method->IsDefaultConflicting() || + default_method->GetDeclaringClass() != super_method->GetDeclaringClass())) { + // Found a default method implementation that is new. + // TODO Refactor this add default methods to virtuals here and not in + // LinkInterfaceMethods maybe. + // The problem is default methods might override previously present + // default-method or miranda-method vtable entries from the superclass. + // Unfortunately we need these to be entries in this class's virtuals. We do not + // give these entries there until LinkInterfaceMethods so we pass this map around + // to let it know which vtable entries need to be updated. + // Make a note that vtable entry j must be updated, store what it needs to be updated + // to. We will allocate a virtual method slot in LinkInterfaceMethods and fix it up + // then. + default_translations->insert( + {j, ClassLinker::MethodTranslation::CreateTranslatedMethod(default_method)}); + VLOG(class_linker) << "Method " << PrettyMethod(super_method) + << " overridden by default " << PrettyMethod(default_method) + << " in " << PrettyClass(klass.Get()); + } + break; + } } } } @@ -4767,23 +4908,75 @@ bool ClassLinker::LinkVirtualMethods( return true; } +// Determine if the given iface has any subinterface in the given list that declares the method +// specified by 'target'. +// +// Arguments +// - self: The thread we are running on +// - target: A comparator that will match any method that overrides the method we are checking for +// - iftable: The iftable we are searching for an overriding method on. +// - ifstart: The index of the interface we are checking to see if anything overrides +// - iface: The interface we are checking to see if anything overrides. +// - image_pointer_size: +// The image pointer size. +// +// Returns +// - True: There is some method that matches the target comparator defined in an interface that +// is a subtype of iface. +// - False: There is no method that matches the target comparator in any interface that is a subtype +// of iface. +static bool ContainsOverridingMethodOf(Thread* self, + MethodNameAndSignatureComparator& target, + Handle<mirror::IfTable> iftable, + size_t ifstart, + Handle<mirror::Class> iface, + size_t image_pointer_size) + SHARED_REQUIRES(Locks::mutator_lock_) { + DCHECK(self != nullptr); + DCHECK(iface.Get() != nullptr); + DCHECK(iftable.Get() != nullptr); + DCHECK_GE(ifstart, 0u); + DCHECK_LT(ifstart, iftable->Count()); + DCHECK_EQ(iface.Get(), iftable->GetInterface(ifstart)); + DCHECK(iface->IsInterface()); + + size_t iftable_count = iftable->Count(); + StackHandleScope<1> hs(self); + MutableHandle<mirror::Class> current_iface(hs.NewHandle<mirror::Class>(nullptr)); + for (size_t k = ifstart + 1; k < iftable_count; k++) { + // Skip ifstart since our current interface obviously cannot override itself. + current_iface.Assign(iftable->GetInterface(k)); + size_t num_instance_methods = current_iface->NumVirtualMethods(); + // Iterate through every method on this interface. The order does not matter so we go forwards. + for (size_t m = 0; m < num_instance_methods; m++) { + ArtMethod* current_method = current_iface->GetVirtualMethodUnchecked(m, image_pointer_size); + if (UNLIKELY(target.HasSameNameAndSignature( + current_method->GetInterfaceMethodIfProxy(image_pointer_size)))) { + // Check if the i'th interface is a subtype of this one. + if (iface->IsAssignableFrom(current_iface.Get())) { + return true; + } + break; + } + } + } + return false; +} + // Find the default method implementation for 'interface_method' in 'klass'. Stores it into -// out_default_method and returns true on success. If no default method was found stores nullptr -// into out_default_method and returns true. If an error occurs (such as a default_method conflict) -// it will fill the icce_message with an appropriate message for an IncompatibleClassChangeError, -// which should then be thrown by the caller. -bool ClassLinker::FindDefaultMethodImplementation(Thread* self, - ArtMethod* target_method, - Handle<mirror::Class> klass, - /*out*/ArtMethod** out_default_method, - /*out*/std::string* icce_message) const { +// out_default_method and returns kDefaultFound on success. If no default method was found return +// kAbstractFound and store nullptr into out_default_method. If an error occurs (such as a +// default_method conflict) it will return kDefaultConflict. +ClassLinker::DefaultMethodSearchResult ClassLinker::FindDefaultMethodImplementation( + Thread* self, + ArtMethod* target_method, + Handle<mirror::Class> klass, + /*out*/ArtMethod** out_default_method) const { DCHECK(self != nullptr); DCHECK(target_method != nullptr); DCHECK(out_default_method != nullptr); - DCHECK(icce_message != nullptr); *out_default_method = nullptr; - mirror::Class* chosen_iface = nullptr; // We organize the interface table so that, for interface I any subinterfaces J follow it in the // table. This lets us walk the table backwards when searching for default methods. The first one @@ -4794,19 +4987,23 @@ bool ClassLinker::FindDefaultMethodImplementation(Thread* self, // The order of unrelated interfaces does not matter and is not defined. size_t iftable_count = klass->GetIfTableCount(); if (iftable_count == 0) { - // No interfaces. We have already reset out to null so just return true. - return true; + // No interfaces. We have already reset out to null so just return kAbstractFound. + return DefaultMethodSearchResult::kAbstractFound; } - StackHandleScope<1> hs(self); + StackHandleScope<3> hs(self); + MutableHandle<mirror::Class> chosen_iface(hs.NewHandle<mirror::Class>(nullptr)); MutableHandle<mirror::IfTable> iftable(hs.NewHandle(klass->GetIfTable())); + MutableHandle<mirror::Class> iface(hs.NewHandle<mirror::Class>(nullptr)); MethodNameAndSignatureComparator target_name_comparator( target_method->GetInterfaceMethodIfProxy(image_pointer_size_)); // Iterates over the klass's iftable in reverse - // We have a break at the end because size_t is unsigned. - for (size_t k = iftable_count - 1; /* break if k == 0 at end */; --k) { + for (size_t k = iftable_count; k != 0; ) { + --k; + DCHECK_LT(k, iftable->Count()); - mirror::Class* iface = iftable->GetInterface(k); + + iface.Assign(iftable->GetInterface(k)); size_t num_instance_methods = iface->NumVirtualMethods(); // Iterate through every method on this interface. The order does not matter so we go forwards. for (size_t m = 0; m < num_instance_methods; m++) { @@ -4819,31 +5016,60 @@ bool ClassLinker::FindDefaultMethodImplementation(Thread* self, } // The verifier should have caught the non-public method. DCHECK(current_method->IsPublic()) << "Interface method is not public!"; - if (UNLIKELY(chosen_iface != nullptr)) { - // We have multiple default impls of the same method. We need to check they do not - // conflict and throw an error if they do. Conflicting means that the current iface is not - // masked by the chosen interface. - if (!iface->IsAssignableFrom(chosen_iface)) { - *icce_message = StringPrintf("Conflicting default method implementations: '%s' and '%s'", - PrettyMethod(current_method).c_str(), - PrettyMethod(*out_default_method).c_str()); - return false; + if (UNLIKELY(chosen_iface.Get() != nullptr)) { + // We have multiple default impls of the same method. This is a potential default conflict. + // We need to check if this possibly conflicting method is either a superclass of the chosen + // default implementation or is overridden by a non-default interface method. In either case + // there is no conflict. + if (!iface->IsAssignableFrom(chosen_iface.Get()) && + !ContainsOverridingMethodOf(self, + target_name_comparator, + iftable, + k, + iface, + image_pointer_size_)) { + LOG(WARNING) << "Conflicting default method implementations found: " + << PrettyMethod(current_method) << " and " + << PrettyMethod(*out_default_method) << " in class " + << PrettyClass(klass.Get()) << " conflict."; + *out_default_method = nullptr; + return DefaultMethodSearchResult::kDefaultConflict; } else { break; // Continue checking at the next interface. } } else { - *out_default_method = current_method; - chosen_iface = iface; - // We should now finish traversing the graph to find if we have default methods that - // conflict. - break; + // chosen_iface == null + if (!ContainsOverridingMethodOf(self, + target_name_comparator, + iftable, + k, + iface, + image_pointer_size_)) { + // Don't set this as the chosen interface if something else is overriding it (because that + // other interface would be potentially chosen instead if it was default). If the other + // interface was abstract then we wouldn't select this interface as chosen anyway since + // the abstract method masks it. + *out_default_method = current_method; + chosen_iface.Assign(iface.Get()); + // We should now finish traversing the graph to find if we have default methods that + // conflict. + } else { + VLOG(class_linker) << "A default method '" << PrettyMethod(current_method) << "' was " + << "skipped because it was overridden by an abstract method in a " + << "subinterface on class '" << PrettyClass(klass.Get()) << "'"; + } } - } - if (k == 0) { break; } } - return true; + if (*out_default_method != nullptr) { + VLOG(class_linker) << "Default method '" << PrettyMethod(*out_default_method) << "' selected " + << "as the implementation for '" << PrettyMethod(target_method) << "' " + << "in '" << PrettyClass(klass.Get()) << "'"; + return DefaultMethodSearchResult::kDefaultFound; + } else { + return DefaultMethodSearchResult::kAbstractFound; + } } // Sets imt_ref appropriately for LinkInterfaceMethods. @@ -4851,7 +5077,7 @@ bool ClassLinker::FindDefaultMethodImplementation(Thread* self, // Otherwise it will set the conflict method which will figure out which method to use during // runtime. static void SetIMTRef(ArtMethod* unimplemented_method, - ArtMethod* conflict_method, + ArtMethod* imt_conflict_method, size_t image_pointer_size, ArtMethod* current_method, /*out*/ArtMethod** imt_ref) @@ -4859,7 +5085,7 @@ static void SetIMTRef(ArtMethod* unimplemented_method, // Place method in imt if entry is empty, place conflict otherwise. if (*imt_ref == unimplemented_method) { *imt_ref = current_method; - } else if (*imt_ref != conflict_method) { + } else if (*imt_ref != imt_conflict_method) { // If we are not a conflict and we have the same signature and name as the imt // entry, it must be that we overwrote a superclass vtable entry. MethodNameAndSignatureComparator imt_comparator( @@ -4868,7 +5094,7 @@ static void SetIMTRef(ArtMethod* unimplemented_method, current_method->GetInterfaceMethodIfProxy(image_pointer_size))) { *imt_ref = current_method; } else { - *imt_ref = conflict_method; + *imt_ref = imt_conflict_method; } } } @@ -5075,10 +5301,23 @@ bool ClassLinker::SetupInterfaceLookupTable(Thread* self, Handle<mirror::Class> return true; } +// Finds the method with a name/signature that matches cmp in the given list of methods. The list of +// methods must be unique. +static ArtMethod* FindSameNameAndSignature(MethodNameAndSignatureComparator& cmp, + const ScopedArenaVector<ArtMethod*>& list) + SHARED_REQUIRES(Locks::mutator_lock_) { + for (ArtMethod* method : list) { + if (cmp.HasSameNameAndSignature(method)) { + return method; + } + } + return nullptr; +} + bool ClassLinker::LinkInterfaceMethods( Thread* self, Handle<mirror::Class> klass, - const std::unordered_map<size_t, ArtMethod*>& default_translations, + const std::unordered_map<size_t, ClassLinker::MethodTranslation>& default_translations, ArtMethod** out_imt) { StackHandleScope<3> hs(self); Runtime* const runtime = Runtime::Current(); @@ -5101,12 +5340,14 @@ bool ClassLinker::LinkInterfaceMethods( // Use the linear alloc pool since this one is in the low 4gb for the compiler. ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool()); ScopedArenaAllocator allocator(&stack); + + ScopedArenaVector<ArtMethod*> default_conflict_methods(allocator.Adapter()); ScopedArenaVector<ArtMethod*> miranda_methods(allocator.Adapter()); ScopedArenaVector<ArtMethod*> default_methods(allocator.Adapter()); MutableHandle<mirror::PointerArray> vtable(hs.NewHandle(klass->GetVTableDuringLinking())); ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); - ArtMethod* const conflict_method = runtime->GetImtConflictMethod(); + ArtMethod* const imt_conflict_method = runtime->GetImtConflictMethod(); // Copy the IMT from the super class if possible. bool extend_super_iftable = false; if (has_superclass) { @@ -5142,8 +5383,8 @@ bool ClassLinker::LinkInterfaceMethods( auto** imt_ref = &out_imt[imt_index]; if (*imt_ref == unimplemented_method) { *imt_ref = method; - } else if (*imt_ref != conflict_method) { - *imt_ref = conflict_method; + } else if (*imt_ref != imt_conflict_method) { + *imt_ref = imt_conflict_method; } } } @@ -5178,7 +5419,16 @@ bool ClassLinker::LinkInterfaceMethods( auto* old_cause = self->StartAssertNoThreadSuspension( "Copying ArtMethods for LinkInterfaceMethods"); - for (size_t i = 0; i < ifcount; ++i) { + // Going in reverse to ensure that we will hit abstract methods that override defaults before the + // defaults. This means we don't need to do any trickery when creating the Miranda methods, since + // they will already be null. This has the additional benefit that the declarer of a miranda + // method will actually declare an abstract method. + for (size_t i = ifcount; i != 0; ) { + --i; + + DCHECK_GE(i, 0u); + DCHECK_LT(i, ifcount); + size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); if (num_methods > 0) { StackHandleScope<2> hs2(self); @@ -5189,6 +5439,11 @@ bool ClassLinker::LinkInterfaceMethods( LengthPrefixedArray<ArtMethod>* input_virtual_methods = nullptr; Handle<mirror::PointerArray> input_vtable_array = NullHandle<mirror::PointerArray>(); int32_t input_array_length = 0; + // TODO Cleanup Needed: In the presence of default methods this optimization is rather dirty + // and confusing. Default methods should always look through all the superclasses + // because they are the last choice of an implementation. We get around this by looking + // at the super-classes iftable methods (copied into method_array previously) when we are + // looking for the implementation of a super-interface method but that is rather dirty. if (super_interface) { // We are overwriting a super class interface, try to only virtual methods instead of the // whole vtable. @@ -5218,8 +5473,7 @@ bool ClassLinker::LinkInterfaceMethods( // // To find defaults we need to do the same but also go over interfaces. bool found_impl = false; - ArtMethod* default_impl = nullptr; - bool found_default_impl = false; + ArtMethod* vtable_impl = nullptr; for (int32_t k = input_array_length - 1; k >= 0; --k) { ArtMethod* vtable_method = input_virtual_methods != nullptr ? &input_virtual_methods->At(k, method_size, method_alignment) : @@ -5236,77 +5490,138 @@ bool ClassLinker::LinkInterfaceMethods( "Method '%s' implementing interface method '%s' is not public", PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str()); return false; - } else if (vtable_method->IsDefault()) { + } else if (UNLIKELY(vtable_method->IsOverridableByDefaultMethod())) { // We might have a newer, better, default method for this, so we just skip it. If we // are still using this we will select it again when scanning for default methods. To // obviate the need to copy the method again we will make a note that we already found // a default here. // TODO This should be much cleaner. - found_default_impl = true; - default_impl = vtable_method; + vtable_impl = vtable_method; break; } else { found_impl = true; + method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); + // Place method in imt if entry is empty, place conflict otherwise. + SetIMTRef(unimplemented_method, + imt_conflict_method, + image_pointer_size_, + vtable_method, + /*out*/imt_ptr); + break; } - method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); - // Place method in imt if entry is empty, place conflict otherwise. - SetIMTRef(unimplemented_method, - conflict_method, - image_pointer_size_, - vtable_method, - /*out*/imt_ptr); - break; } } - // We should only search for default implementations when the class does not implement the - // method directly and either (1) the interface is newly implemented on this class and not - // on any of its superclasses, (2) the superclass's implementation is a default method, or - // (3) the superclass does not have an implementation. - if (!found_impl && (!super_interface || - method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_) - ->IsOverridableByDefaultMethod())) { - ArtMethod* current_method = nullptr; - std::string icce_message; - if (!FindDefaultMethodImplementation(self, - interface_method, - klass, - /*out*/¤t_method, - /*out*/&icce_message)) { - // There was a conflict with default method implementations. - self->EndAssertNoThreadSuspension(old_cause); - // TODO This should actually be thrown when we attempt to invoke this method. - ThrowIncompatibleClassChangeError(klass.Get(), "%s", icce_message.c_str()); - return false; - } else if (current_method != nullptr) { - if (found_default_impl && - current_method->GetDeclaringClass() == default_impl->GetDeclaringClass()) { + // Continue on to the next method if we are done. + if (LIKELY(found_impl)) { + continue; + } else if (LIKELY(super_interface)) { + // Don't look for a default implementation when the super-method is implemented directly + // by the class. + // + // See if we can use the superclasses method and skip searching everything else. + // Note: !found_impl && super_interface + CHECK(extend_super_iftable); + // If this is a super_interface method it is possible we shouldn't override it because a + // superclass could have implemented it directly. We get the method the superclass used + // to implement this to know if we can override it with a default method. Doing this is + // safe since we know that the super_iftable is filled in so we can simply pull it from + // there. We don't bother if this is not a super-classes interface since in that case we + // have scanned the entire vtable anyway and would have found it. + // TODO This is rather dirty but it is faster than searching through the entire vtable + // every time. + ArtMethod* supers_method = + method_array->GetElementPtrSize<ArtMethod*>(j, image_pointer_size_); + DCHECK(supers_method != nullptr); + DCHECK(interface_name_comparator.HasSameNameAndSignature(supers_method)); + if (!supers_method->IsOverridableByDefaultMethod()) { + // The method is not overridable by a default method (i.e. it is directly implemented + // in some class). Therefore move onto the next interface method. + continue; + } + } + // If we haven't found it yet we should search through the interfaces for default methods. + ArtMethod* current_method = nullptr; + switch (FindDefaultMethodImplementation(self, + interface_method, + klass, + /*out*/¤t_method)) { + case DefaultMethodSearchResult::kDefaultConflict: { + // Default method conflict. + DCHECK(current_method == nullptr); + ArtMethod* default_conflict_method = nullptr; + if (vtable_impl != nullptr && vtable_impl->IsDefaultConflicting()) { + // We can reuse the method from the superclass, don't bother adding it to virtuals. + default_conflict_method = vtable_impl; + } else { + // See if we already have a conflict method for this method. + ArtMethod* preexisting_conflict = FindSameNameAndSignature(interface_name_comparator, + default_conflict_methods); + if (LIKELY(preexisting_conflict != nullptr)) { + // We already have another conflict we can reuse. + default_conflict_method = preexisting_conflict; + } else { + // Create a new conflict method for this to use. + default_conflict_method = + reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size)); + new(default_conflict_method) ArtMethod(interface_method, image_pointer_size_); + default_conflict_methods.push_back(default_conflict_method); + } + } + current_method = default_conflict_method; + break; + } + case DefaultMethodSearchResult::kDefaultFound: { + DCHECK(current_method != nullptr); + // Found a default method. + if (vtable_impl != nullptr && + current_method->GetDeclaringClass() == vtable_impl->GetDeclaringClass()) { // We found a default method but it was the same one we already have from our // superclass. Don't bother adding it to our vtable again. - current_method = default_impl; + current_method = vtable_impl; } else { - // We found a default method implementation and there were no conflicts. - // Save the default method. We need to add it to the vtable. - default_methods.push_back(current_method); + // Only record this default method if it is new to save space. + ArtMethod* old = FindSameNameAndSignature(interface_name_comparator, default_methods); + if (old == nullptr) { + // We found a default method implementation and there were no conflicts. + // Save the default method. We need to add it to the vtable. + default_methods.push_back(current_method); + } else { + CHECK(old == current_method) << "Multiple default implementations selected!"; + } } - method_array->SetElementPtrSize(j, current_method, image_pointer_size_); - SetIMTRef(unimplemented_method, - conflict_method, - image_pointer_size_, - current_method, - /*out*/imt_ptr); - found_impl = true; + break; } - } - if (!found_impl && !super_interface) { - // It is defined in this class or any of its subclasses. - ArtMethod* miranda_method = nullptr; - for (auto& mir_method : miranda_methods) { - if (interface_name_comparator.HasSameNameAndSignature(mir_method)) { - miranda_method = mir_method; - break; + case DefaultMethodSearchResult::kAbstractFound: { + DCHECK(current_method == nullptr); + // Abstract method masks all defaults. + if (vtable_impl != nullptr && + vtable_impl->IsAbstract() && + !vtable_impl->IsDefaultConflicting()) { + // We need to make this an abstract method but the version in the vtable already is so + // don't do anything. + current_method = vtable_impl; } + break; } + } + if (current_method != nullptr) { + // We found a default method implementation. Record it in the iftable and IMT. + method_array->SetElementPtrSize(j, current_method, image_pointer_size_); + SetIMTRef(unimplemented_method, + imt_conflict_method, + image_pointer_size_, + current_method, + /*out*/imt_ptr); + } else if (!super_interface) { + // We could not find an implementation for this method and since it is a brand new + // interface we searched the entire vtable (and all default methods) for an implementation + // but couldn't find one. We therefore need to make a miranda method. + // + // Find out if there is already a miranda method we can use. + ArtMethod* miranda_method = FindSameNameAndSignature(interface_name_comparator, + miranda_methods); if (miranda_method == nullptr) { + DCHECK(interface_method->IsAbstract()) << PrettyMethod(interface_method); miranda_method = reinterpret_cast<ArtMethod*>(allocator.Alloc(method_size)); CHECK(miranda_method != nullptr); // Point the interface table at a phantom slot. @@ -5318,10 +5633,15 @@ bool ClassLinker::LinkInterfaceMethods( } } } - if (!miranda_methods.empty() || !default_methods.empty()) { + if (!miranda_methods.empty() || !default_methods.empty() || !default_conflict_methods.empty()) { + VLOG(class_linker) << PrettyClass(klass.Get()) << ": miranda_methods=" << miranda_methods.size() + << " default_methods=" << default_methods.size() + << " default_conflict_methods=" << default_conflict_methods.size(); const size_t old_method_count = klass->NumVirtualMethods(); - const size_t new_method_count = - old_method_count + miranda_methods.size() + default_methods.size(); + const size_t new_method_count = old_method_count + + miranda_methods.size() + + default_methods.size() + + default_conflict_methods.size(); // Attempt to realloc to save RAM if possible. LengthPrefixedArray<ArtMethod>* old_virtuals = klass->GetVirtualMethodsPtr(); // The Realloced virtual methods aren't visiblef from the class roots, so there is no issue @@ -5379,15 +5699,32 @@ bool ClassLinker::LinkInterfaceMethods( for (ArtMethod* def_method : default_methods) { ArtMethod& new_method = *out; new_method.CopyFrom(def_method, image_pointer_size_); - new_method.SetAccessFlags(new_method.GetAccessFlags() | kAccDefault); // Clear the preverified flag if it is present. Since this class hasn't been verified yet it // shouldn't have methods that are preverified. // TODO This is rather arbitrary. We should maybe support classes where only some of its // methods are preverified. - new_method.SetAccessFlags(new_method.GetAccessFlags() & ~kAccPreverified); + new_method.SetAccessFlags((new_method.GetAccessFlags() | kAccDefault) & ~kAccPreverified); move_table.emplace(def_method, &new_method); ++out; } + for (ArtMethod* conf_method : default_conflict_methods) { + ArtMethod& new_method = *out; + new_method.CopyFrom(conf_method, image_pointer_size_); + // This is a type of default method (there are default method impls, just a conflict) so mark + // this as a default, non-abstract method, since thats what it is. Also clear the preverified + // bit since this class hasn't been verified yet it shouldn't have methods that are + // preverified. + constexpr uint32_t kSetFlags = kAccDefault | kAccDefaultConflict; + constexpr uint32_t kMaskFlags = ~(kAccAbstract | kAccPreverified); + new_method.SetAccessFlags((new_method.GetAccessFlags() | kSetFlags) & kMaskFlags); + DCHECK(new_method.IsDefaultConflicting()); + // The actual method might or might not be marked abstract since we just copied it from a + // (possibly default) interface method. We need to set it entry point to be the bridge so that + // the compiler will not invoke the implementation of whatever method we copied from. + EnsureThrowsInvocationError(&new_method); + move_table.emplace(conf_method, &new_method); + ++out; + } virtuals->SetSize(new_method_count); UpdateClassVirtualMethods(klass.Get(), virtuals); // Done copying methods, they are all roots in the class now, so we can end the no thread @@ -5395,8 +5732,10 @@ bool ClassLinker::LinkInterfaceMethods( self->EndAssertNoThreadSuspension(old_cause); const size_t old_vtable_count = vtable->GetLength(); - const size_t new_vtable_count = - old_vtable_count + miranda_methods.size() + default_methods.size(); + const size_t new_vtable_count = old_vtable_count + + miranda_methods.size() + + default_methods.size() + + default_conflict_methods.size(); miranda_methods.clear(); vtable.Assign(down_cast<mirror::PointerArray*>(vtable->CopyOf(self, new_vtable_count))); if (UNLIKELY(vtable.Get() == nullptr)) { @@ -5421,9 +5760,27 @@ bool ClassLinker::LinkInterfaceMethods( auto translation_it = default_translations.find(i); bool found_translation = false; if (translation_it != default_translations.end()) { - size_t vtable_index; - std::tie(vtable_index, translated_method) = *translation_it; - DCHECK_EQ(vtable_index, i); + if (translation_it->second.IsInConflict()) { + // Find which conflict method we are to use for this method. + MethodNameAndSignatureComparator old_method_comparator( + translated_method->GetInterfaceMethodIfProxy(image_pointer_size_)); + ArtMethod* new_conflict_method = FindSameNameAndSignature(old_method_comparator, + default_conflict_methods); + CHECK(new_conflict_method != nullptr) << "Expected a conflict method!"; + translated_method = new_conflict_method; + } else if (translation_it->second.IsAbstract()) { + // Find which miranda method we are to use for this method. + MethodNameAndSignatureComparator old_method_comparator( + translated_method->GetInterfaceMethodIfProxy(image_pointer_size_)); + ArtMethod* miranda_method = FindSameNameAndSignature(old_method_comparator, + miranda_methods); + DCHECK(miranda_method != nullptr); + translated_method = miranda_method; + } else { + // Normal default method (changed from an older default or abstract interface method). + DCHECK(translation_it->second.IsTranslation()); + translated_method = translation_it->second.GetTranslation(); + } found_translation = true; } DCHECK(translated_method != nullptr); @@ -6130,8 +6487,8 @@ void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const { void ClassLinker::DumpForSigQuit(std::ostream& os) { ScopedObjectAccess soa(Thread::Current()); - if (dex_cache_image_class_lookup_required_) { - MoveImageClassesToClassTable(); + if (dex_cache_boot_image_class_lookup_required_) { + AddBootImageClassesToClassTable(); } ReaderMutexLock mu(soa.Self(), *Locks::classlinker_classes_lock_); os << "Zygote loaded classes=" << NumZygoteClasses() << " post zygote classes=" @@ -6168,8 +6525,8 @@ size_t ClassLinker::NumNonZygoteClasses() const { } size_t ClassLinker::NumLoadedClasses() { - if (dex_cache_image_class_lookup_required_) { - MoveImageClassesToClassTable(); + if (dex_cache_boot_image_class_lookup_required_) { + AddBootImageClassesToClassTable(); } ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); // Only return non zygote classes since these are the ones which apps which care about. @@ -6272,7 +6629,9 @@ bool ClassLinker::MayBeCalledWithDirectCodePointer(ArtMethod* m) { } } -jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector<const DexFile*>& dex_files) { +jobject ClassLinker::CreatePathClassLoader(Thread* self, + std::vector<const DexFile*>& dex_files, + jobject parent_loader) { // SOAAlreadyRunnable is protected, and we need something to add a global reference. // We could move the jobject to the callers, but all call-sites do this... ScopedObjectAccessUnchecked soa(self); @@ -6303,8 +6662,8 @@ jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector<const DexFi for (const DexFile* dex_file : dex_files) { StackHandleScope<3> hs2(self); - // CreatePathClassLoader is only used by gtests. Index 0 of h_long_array is supposed to be the - // oat file but we can leave it null. + // CreatePathClassLoader is only used by gtests and dex2oat. Index 0 of h_long_array is + // supposed to be the oat file but we can leave it null. Handle<mirror::LongArray> h_long_array = hs2.NewHandle(mirror::LongArray::Alloc( self, kDexFileIndexStart + 1)); @@ -6350,9 +6709,10 @@ jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector<const DexFi mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent", "Ljava/lang/ClassLoader;"); DCHECK(parent_field != nullptr); - mirror::Object* boot_cl = - soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); - parent_field->SetObject<false>(h_path_class_loader.Get(), boot_cl); + mirror::Object* parent = (parent_loader != nullptr) + ? soa.Decode<mirror::ClassLoader*>(parent_loader) + : soa.Decode<mirror::Class*>(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); + parent_field->SetObject<false>(h_path_class_loader.Get(), parent); // Make it a global ref and return. ScopedLocalRef<jobject> local_ref( |