|  | /* | 
|  | * Copyright (C) 2011 The Android Open Source Project | 
|  | * | 
|  | * Licensed under the Apache License, Version 2.0 (the "License"); | 
|  | * you may not use this file except in compliance with the License. | 
|  | * You may obtain a copy of the License at | 
|  | * | 
|  | *      http://www.apache.org/licenses/LICENSE-2.0 | 
|  | * | 
|  | * Unless required by applicable law or agreed to in writing, software | 
|  | * distributed under the License is distributed on an "AS IS" BASIS, | 
|  | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | 
|  | * See the License for the specific language governing permissions and | 
|  | * limitations under the License. | 
|  | */ | 
|  |  | 
|  | #ifndef ART_RUNTIME_CLASS_LINKER_INL_H_ | 
|  | #define ART_RUNTIME_CLASS_LINKER_INL_H_ | 
|  |  | 
|  | #include "art_field.h" | 
|  | #include "class_linker.h" | 
|  | #include "gc_root-inl.h" | 
|  | #include "gc/heap-inl.h" | 
|  | #include "obj_ptr-inl.h" | 
|  | #include "mirror/class_loader.h" | 
|  | #include "mirror/dex_cache-inl.h" | 
|  | #include "mirror/iftable.h" | 
|  | #include "mirror/throwable.h" | 
|  | #include "mirror/object_array.h" | 
|  | #include "handle_scope-inl.h" | 
|  | #include "scoped_thread_state_change-inl.h" | 
|  |  | 
|  | #include <atomic> | 
|  |  | 
|  | namespace art { | 
|  |  | 
|  | inline mirror::Class* ClassLinker::FindSystemClass(Thread* self, const char* descriptor) { | 
|  | return FindClass(self, descriptor, ScopedNullHandle<mirror::ClassLoader>()); | 
|  | } | 
|  |  | 
|  | inline mirror::Class* ClassLinker::FindArrayClass(Thread* self, | 
|  | ObjPtr<mirror::Class>* element_class) { | 
|  | for (size_t i = 0; i < kFindArrayCacheSize; ++i) { | 
|  | // Read the cached array class once to avoid races with other threads setting it. | 
|  | ObjPtr<mirror::Class> array_class = find_array_class_cache_[i].Read(); | 
|  | if (array_class != nullptr && array_class->GetComponentType() == *element_class) { | 
|  | return array_class.Ptr(); | 
|  | } | 
|  | } | 
|  | std::string descriptor = "["; | 
|  | std::string temp; | 
|  | descriptor += (*element_class)->GetDescriptor(&temp); | 
|  | StackHandleScope<2> hs(Thread::Current()); | 
|  | Handle<mirror::ClassLoader> class_loader(hs.NewHandle((*element_class)->GetClassLoader())); | 
|  | HandleWrapperObjPtr<mirror::Class> h_element_class(hs.NewHandleWrapper(element_class)); | 
|  | ObjPtr<mirror::Class> array_class = FindClass(self, descriptor.c_str(), class_loader); | 
|  | if (array_class != nullptr) { | 
|  | // Benign races in storing array class and incrementing index. | 
|  | size_t victim_index = find_array_class_cache_next_victim_; | 
|  | find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class); | 
|  | find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize; | 
|  | } else { | 
|  | // We should have a NoClassDefFoundError. | 
|  | self->AssertPendingException(); | 
|  | } | 
|  | return array_class.Ptr(); | 
|  | } | 
|  |  | 
|  | inline mirror::String* ClassLinker::ResolveString(dex::StringIndex string_idx, | 
|  | ArtMethod* referrer) { | 
|  | Thread::PoisonObjectPointersIfDebug(); | 
|  | ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass(); | 
|  | // MethodVerifier refuses methods with string_idx out of bounds. | 
|  | DCHECK_LT(string_idx.index_, declaring_class->GetDexFile().NumStringIds()); | 
|  | ObjPtr<mirror::String> string = | 
|  | mirror::StringDexCachePair::Lookup(declaring_class->GetDexCache()->GetStrings(), | 
|  | string_idx.index_, | 
|  | mirror::DexCache::kDexCacheStringCacheSize).Read(); | 
|  | if (UNLIKELY(string == nullptr)) { | 
|  | StackHandleScope<1> hs(Thread::Current()); | 
|  | Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache())); | 
|  | const DexFile& dex_file = *dex_cache->GetDexFile(); | 
|  | string = ResolveString(dex_file, string_idx, dex_cache); | 
|  | } | 
|  | return string.Ptr(); | 
|  | } | 
|  |  | 
|  | inline mirror::Class* ClassLinker::ResolveType(dex::TypeIndex type_idx, ArtMethod* referrer) { | 
|  | Thread::PoisonObjectPointersIfDebug(); | 
|  | if (kIsDebugBuild) { | 
|  | Thread::Current()->AssertNoPendingException(); | 
|  | } | 
|  | ObjPtr<mirror::Class> resolved_type = | 
|  | referrer->GetDexCacheResolvedType(type_idx, image_pointer_size_); | 
|  | if (UNLIKELY(resolved_type == nullptr)) { | 
|  | StackHandleScope<2> hs(Thread::Current()); | 
|  | // There could be an out of bounds exception from GetDexCacheResolvedType, don't call | 
|  | // ResolveType for this case. | 
|  | if (LIKELY(!hs.Self()->IsExceptionPending())) { | 
|  | ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass(); | 
|  | Handle<mirror::DexCache> dex_cache(hs.NewHandle(declaring_class->GetDexCache())); | 
|  | Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader())); | 
|  | const DexFile& dex_file = *dex_cache->GetDexFile(); | 
|  | resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader); | 
|  | // Note: We cannot check here to see whether we added the type to the cache. The type | 
|  | //       might be an erroneous class, which results in it being hidden from us. | 
|  | } else { | 
|  | // Make sure its an array out of bounds exception. | 
|  | DCHECK(hs.Self()->GetException()->GetClass()->DescriptorEquals( | 
|  | "Ljava/lang/ArrayIndexOutOfBoundsException;")); | 
|  | } | 
|  | } | 
|  | return resolved_type.Ptr(); | 
|  | } | 
|  |  | 
|  | inline mirror::Class* ClassLinker::ResolveType(dex::TypeIndex type_idx, ArtField* referrer) { | 
|  | Thread::PoisonObjectPointersIfDebug(); | 
|  | ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass(); | 
|  | ObjPtr<mirror::DexCache> dex_cache_ptr = declaring_class->GetDexCache(); | 
|  | ObjPtr<mirror::Class> resolved_type = dex_cache_ptr->GetResolvedType(type_idx); | 
|  | if (UNLIKELY(resolved_type == nullptr)) { | 
|  | StackHandleScope<2> hs(Thread::Current()); | 
|  | Handle<mirror::DexCache> dex_cache(hs.NewHandle(dex_cache_ptr)); | 
|  | Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader())); | 
|  | const DexFile& dex_file = *dex_cache->GetDexFile(); | 
|  | resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader); | 
|  | // Note: We cannot check here to see whether we added the type to the cache. The type | 
|  | //       might be an erroneous class, which results in it being hidden from us. | 
|  | } | 
|  | return resolved_type.Ptr(); | 
|  | } | 
|  |  | 
|  | inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) { | 
|  | ArtMethod* resolved_method = referrer->GetDexCacheResolvedMethod(method_idx, image_pointer_size_); | 
|  | if (resolved_method == nullptr || resolved_method->IsRuntimeMethod()) { | 
|  | return nullptr; | 
|  | } | 
|  | return resolved_method; | 
|  | } | 
|  |  | 
|  | inline mirror::Class* ClassLinker::ResolveReferencedClassOfMethod( | 
|  | uint32_t method_idx, | 
|  | Handle<mirror::DexCache> dex_cache, | 
|  | Handle<mirror::ClassLoader> class_loader) { | 
|  | // NB: We cannot simply use `GetResolvedMethod(method_idx, ...)->GetDeclaringClass()`. This is | 
|  | // because if we did so than an invoke-super could be incorrectly dispatched in cases where | 
|  | // GetMethodId(method_idx).class_idx_ refers to a non-interface, non-direct-superclass | 
|  | // (super*-class?) of the referrer and the direct superclass of the referrer contains a concrete | 
|  | // implementation of the method. If this class's implementation of the method is copied from an | 
|  | // interface (either miranda, default or conflict) we would incorrectly assume that is what we | 
|  | // want to invoke on, instead of the 'concrete' implementation that the direct superclass | 
|  | // contains. | 
|  | const DexFile* dex_file = dex_cache->GetDexFile(); | 
|  | const DexFile::MethodId& method = dex_file->GetMethodId(method_idx); | 
|  | ObjPtr<mirror::Class> resolved_type = dex_cache->GetResolvedType(method.class_idx_); | 
|  | if (UNLIKELY(resolved_type == nullptr)) { | 
|  | resolved_type = ResolveType(*dex_file, method.class_idx_, dex_cache, class_loader); | 
|  | } | 
|  | return resolved_type.Ptr(); | 
|  | } | 
|  |  | 
|  | template <ClassLinker::ResolveMode kResolveMode> | 
|  | inline ArtMethod* ClassLinker::ResolveMethod(Thread* self, | 
|  | uint32_t method_idx, | 
|  | ArtMethod* referrer, | 
|  | InvokeType type) { | 
|  | ArtMethod* resolved_method = GetResolvedMethod(method_idx, referrer); | 
|  | Thread::PoisonObjectPointersIfDebug(); | 
|  | if (UNLIKELY(resolved_method == nullptr)) { | 
|  | ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass(); | 
|  | StackHandleScope<2> hs(self); | 
|  | Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(declaring_class->GetDexCache())); | 
|  | Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader())); | 
|  | const DexFile* dex_file = h_dex_cache->GetDexFile(); | 
|  | resolved_method = ResolveMethod<kResolveMode>(*dex_file, | 
|  | method_idx, | 
|  | h_dex_cache, | 
|  | h_class_loader, | 
|  | referrer, | 
|  | type); | 
|  | } | 
|  | // Note: We cannot check here to see whether we added the method to the cache. It | 
|  | //       might be an erroneous class, which results in it being hidden from us. | 
|  | return resolved_method; | 
|  | } | 
|  |  | 
|  | inline ArtField* ClassLinker::GetResolvedField(uint32_t field_idx, | 
|  | ObjPtr<mirror::DexCache> dex_cache) { | 
|  | return dex_cache->GetResolvedField(field_idx, image_pointer_size_); | 
|  | } | 
|  |  | 
|  | inline ArtField* ClassLinker::ResolveField(uint32_t field_idx, | 
|  | ArtMethod* referrer, | 
|  | bool is_static) { | 
|  | Thread::PoisonObjectPointersIfDebug(); | 
|  | ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass(); | 
|  | ArtField* resolved_field = GetResolvedField(field_idx, referrer->GetDexCache()); | 
|  | if (UNLIKELY(resolved_field == nullptr)) { | 
|  | StackHandleScope<2> hs(Thread::Current()); | 
|  | Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache())); | 
|  | Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader())); | 
|  | const DexFile& dex_file = *dex_cache->GetDexFile(); | 
|  | resolved_field = ResolveField(dex_file, field_idx, dex_cache, class_loader, is_static); | 
|  | // Note: We cannot check here to see whether we added the field to the cache. The type | 
|  | //       might be an erroneous class, which results in it being hidden from us. | 
|  | } | 
|  | return resolved_field; | 
|  | } | 
|  |  | 
|  | inline mirror::Object* ClassLinker::AllocObject(Thread* self) { | 
|  | return GetClassRoot(kJavaLangObject)->Alloc<true, false>( | 
|  | self, | 
|  | Runtime::Current()->GetHeap()->GetCurrentAllocator()).Ptr(); | 
|  | } | 
|  |  | 
|  | template <class T> | 
|  | inline mirror::ObjectArray<T>* ClassLinker::AllocObjectArray(Thread* self, size_t length) { | 
|  | return mirror::ObjectArray<T>::Alloc(self, GetClassRoot(kObjectArrayClass), length); | 
|  | } | 
|  |  | 
|  | inline mirror::ObjectArray<mirror::Class>* ClassLinker::AllocClassArray(Thread* self, | 
|  | size_t length) { | 
|  | return mirror::ObjectArray<mirror::Class>::Alloc(self, GetClassRoot(kClassArrayClass), length); | 
|  | } | 
|  |  | 
|  | inline mirror::ObjectArray<mirror::String>* ClassLinker::AllocStringArray(Thread* self, | 
|  | size_t length) { | 
|  | return mirror::ObjectArray<mirror::String>::Alloc(self, | 
|  | GetClassRoot(kJavaLangStringArrayClass), | 
|  | length); | 
|  | } | 
|  |  | 
|  | inline mirror::IfTable* ClassLinker::AllocIfTable(Thread* self, size_t ifcount) { | 
|  | return down_cast<mirror::IfTable*>( | 
|  | mirror::IfTable::Alloc(self, | 
|  | GetClassRoot(kObjectArrayClass), | 
|  | ifcount * mirror::IfTable::kMax)); | 
|  | } | 
|  |  | 
|  | inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root) { | 
|  | DCHECK(!class_roots_.IsNull()); | 
|  | mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read(); | 
|  | ObjPtr<mirror::Class> klass = class_roots->Get(class_root); | 
|  | DCHECK(klass != nullptr); | 
|  | return klass.Ptr(); | 
|  | } | 
|  |  | 
|  | template<ReadBarrierOption kReadBarrierOption> | 
|  | ArtMethod* ClassLinker::FindMethodForProxy(ObjPtr<mirror::Class> proxy_class, | 
|  | ArtMethod* proxy_method) { | 
|  | DCHECK(proxy_class->IsProxyClass()); | 
|  | DCHECK(proxy_method->IsProxyMethod<kReadBarrierOption>()); | 
|  | { | 
|  | Thread* const self = Thread::Current(); | 
|  | ReaderMutexLock mu(self, *Locks::dex_lock_); | 
|  | // Locate the dex cache of the original interface/Object | 
|  | for (const DexCacheData& data : dex_caches_) { | 
|  | if (!self->IsJWeakCleared(data.weak_root) && | 
|  | proxy_method->HasSameDexCacheResolvedTypes(data.resolved_types, | 
|  | image_pointer_size_)) { | 
|  | ObjPtr<mirror::DexCache> dex_cache = | 
|  | ObjPtr<mirror::DexCache>::DownCast(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; | 
|  | } | 
|  | } | 
|  | } | 
|  | } | 
|  | LOG(FATAL) << "Didn't find dex cache for " << proxy_class->PrettyClass() << " " | 
|  | << proxy_method->PrettyMethod(); | 
|  | UNREACHABLE(); | 
|  | } | 
|  |  | 
|  | }  // namespace art | 
|  |  | 
|  | #endif  // ART_RUNTIME_CLASS_LINKER_INL_H_ |