/*
* 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/heap-inl.h"
#include "gc_root-inl.h"
#include "handle_scope-inl.h"
#include "mirror/class_loader.h"
#include "mirror/dex_cache-inl.h"
#include "mirror/iftable.h"
#include "mirror/object_array-inl.h"
#include "obj_ptr-inl.h"
#include "scoped_thread_state_change-inl.h"
#include <atomic>
namespace art {
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 ObjPtr<mirror::Class> ClassLinker::ResolveType(dex::TypeIndex type_idx,
ObjPtr<mirror::Class> referrer) {
if (kObjPtrPoisoning) {
StackHandleScope<1> hs(Thread::Current());
HandleWrapperObjPtr<mirror::Class> referrer_wrapper = hs.NewHandleWrapper(&referrer);
Thread::Current()->PoisonObjectPointers();
}
if (kIsDebugBuild) {
Thread::Current()->AssertNoPendingException();
}
// We do not need the read barrier for getting the DexCache for the initial resolved type
// lookup as both from-space and to-space copies point to the same native resolved types array.
ObjPtr<mirror::Class> resolved_type =
referrer->GetDexCache<kDefaultVerifyFlags, kWithoutReadBarrier>()->GetResolvedType(type_idx);
if (resolved_type == nullptr) {
StackHandleScope<2> hs(Thread::Current());
Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(referrer->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referrer->GetClassLoader()));
resolved_type = DoResolveType(type_idx, h_dex_cache, class_loader);
}
return resolved_type;
}
inline ObjPtr<mirror::Class> ClassLinker::ResolveType(dex::TypeIndex type_idx,
ArtMethod* referrer) {
Thread::PoisonObjectPointersIfDebug();
if (kIsDebugBuild) {
Thread::Current()->AssertNoPendingException();
}
// We do not need the read barrier for getting the DexCache for the initial resolved type
// lookup as both from-space and to-space copies point to the same native resolved types array.
ObjPtr<mirror::Class> resolved_type =
referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedType(type_idx);
if (UNLIKELY(resolved_type == nullptr)) {
StackHandleScope<2> hs(Thread::Current());
ObjPtr<mirror::Class> referring_class = referrer->GetDeclaringClass();
Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referring_class->GetClassLoader()));
resolved_type = DoResolveType(type_idx, dex_cache, class_loader);
}
return resolved_type;
}
inline ObjPtr<mirror::Class> ClassLinker::ResolveType(dex::TypeIndex type_idx,
Handle<mirror::DexCache> dex_cache,
Handle<mirror::ClassLoader> class_loader) {
DCHECK(dex_cache != nullptr);
Thread::PoisonObjectPointersIfDebug();
ObjPtr<mirror::Class> resolved = dex_cache->GetResolvedType(type_idx);
if (resolved == nullptr) {
resolved = DoResolveType(type_idx, dex_cache, class_loader);
}
return resolved;
}
inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(dex::TypeIndex type_idx,
ObjPtr<mirror::Class> referrer) {
// We do not need the read barrier for getting the DexCache for the initial resolved type
// lookup as both from-space and to-space copies point to the same native resolved types array.
ObjPtr<mirror::Class> type =
referrer->GetDexCache<kDefaultVerifyFlags, kWithoutReadBarrier>()->GetResolvedType(type_idx);
if (type == nullptr) {
type = DoLookupResolvedType(type_idx, referrer->GetDexCache(), referrer->GetClassLoader());
}
return type;
}
inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(dex::TypeIndex type_idx,
ArtMethod* referrer) {
// We do not need the read barrier for getting the DexCache for the initial resolved type
// lookup as both from-space and to-space copies point to the same native resolved types array.
ObjPtr<mirror::Class> type =
referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedType(type_idx);
if (type == nullptr) {
type = DoLookupResolvedType(type_idx, referrer->GetDexCache(), referrer->GetClassLoader());
}
return type;
}
inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(
dex::TypeIndex type_idx,
ObjPtr<mirror::DexCache> dex_cache,
ObjPtr<mirror::ClassLoader> class_loader) {
ObjPtr<mirror::Class> type = dex_cache->GetResolvedType(type_idx);
if (type == nullptr) {
type = DoLookupResolvedType(type_idx, dex_cache, class_loader);
}
return type;
}
template <bool kThrowOnError, typename ClassGetter>
inline bool ClassLinker::CheckInvokeClassMismatch(ObjPtr<mirror::DexCache> dex_cache,
InvokeType type,
ClassGetter class_getter) {
switch (type) {
case kStatic:
case kSuper:
break;
case kInterface: {
// We have to check whether the method id really belongs to an interface (dex static bytecode
// constraints A15, A16). Otherwise you must not invoke-interface on it.
ObjPtr<mirror::Class> klass = class_getter();
if (UNLIKELY(!klass->IsInterface())) {
if (kThrowOnError) {
ThrowIncompatibleClassChangeError(klass,
"Found class %s, but interface was expected",
klass->PrettyDescriptor().c_str());
}
return true;
}
break;
}
case kDirect:
if (dex_cache->GetDexFile()->SupportsDefaultMethods()) {
break;
}
FALLTHROUGH_INTENDED;
case kVirtual: {
// Similarly, invoke-virtual (and invoke-direct without default methods) must reference
// a non-interface class (dex static bytecode constraint A24, A25).
ObjPtr<mirror::Class> klass = class_getter();
if (UNLIKELY(klass->IsInterface())) {
if (kThrowOnError) {
ThrowIncompatibleClassChangeError(klass,
"Found interface %s, but class was expected",
klass->PrettyDescriptor().c_str());
}
return true;
}
break;
}
default:
LOG(FATAL) << "Unreachable - invocation type: " << type;
UNREACHABLE();
}
return false;
}
template <bool kThrow>
inline bool ClassLinker::CheckInvokeClassMismatch(ObjPtr<mirror::DexCache> dex_cache,
InvokeType type,
uint32_t method_idx,
ObjPtr<mirror::ClassLoader> class_loader) {
return CheckInvokeClassMismatch<kThrow>(
dex_cache,
type,
[this, dex_cache, method_idx, class_loader]() REQUIRES_SHARED(Locks::mutator_lock_) {
const DexFile::MethodId& method_id = dex_cache->GetDexFile()->GetMethodId(method_idx);
ObjPtr<mirror::Class> klass =
LookupResolvedType(method_id.class_idx_, dex_cache, class_loader);
DCHECK(klass != nullptr);
return klass;
});
}
inline ArtMethod* ClassLinker::LookupResolvedMethod(uint32_t method_idx,
ObjPtr<mirror::DexCache> dex_cache,
ObjPtr<mirror::ClassLoader> class_loader) {
PointerSize pointer_size = image_pointer_size_;
ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, pointer_size);
if (resolved == nullptr) {
const DexFile& dex_file = *dex_cache->GetDexFile();
const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx);
ObjPtr<mirror::Class> klass = LookupResolvedType(method_id.class_idx_, dex_cache, class_loader);
if (klass != nullptr) {
resolved = FindResolvedMethod(klass, dex_cache, class_loader, method_idx);
}
}
return resolved;
}
template <InvokeType type, ClassLinker::ResolveMode kResolveMode>
inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) {
DCHECK(referrer != nullptr);
// Note: The referrer can be a Proxy constructor. In that case, we need to do the
// lookup in the context of the original method from where it steals the code.
// However, we delay the GetInterfaceMethodIfProxy() until needed.
DCHECK(!referrer->IsProxyMethod() || referrer->IsConstructor());
// We do not need the read barrier for getting the DexCache for the initial resolved method
// lookup as both from-space and to-space copies point to the same native resolved methods array.
ArtMethod* resolved_method = referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedMethod(
method_idx, image_pointer_size_);
if (resolved_method == nullptr) {
return nullptr;
}
DCHECK(!resolved_method->IsRuntimeMethod());
if (kResolveMode == ResolveMode::kCheckICCEAndIAE) {
referrer = referrer->GetInterfaceMethodIfProxy(image_pointer_size_);
// Check if the invoke type matches the class type.
ObjPtr<mirror::DexCache> dex_cache = referrer->GetDexCache();
ObjPtr<mirror::ClassLoader> class_loader = referrer->GetClassLoader();
if (CheckInvokeClassMismatch</* kThrow */ false>(dex_cache, type, method_idx, class_loader)) {
return nullptr;
}
// Check access.
ObjPtr<mirror::Class> referring_class = referrer->GetDeclaringClass();
if (!referring_class->CanAccessResolvedMethod(resolved_method->GetDeclaringClass(),
resolved_method,
dex_cache,
method_idx)) {
return nullptr;
}
// Check if the invoke type matches the method type.
if (UNLIKELY(resolved_method->CheckIncompatibleClassChange(type))) {
return nullptr;
}
}
return resolved_method;
}
template <ClassLinker::ResolveMode kResolveMode>
inline ArtMethod* ClassLinker::ResolveMethod(Thread* self,
uint32_t method_idx,
ArtMethod* referrer,
InvokeType type) {
DCHECK(referrer != nullptr);
// Note: The referrer can be a Proxy constructor. In that case, we need to do the
// lookup in the context of the original method from where it steals the code.
// However, we delay the GetInterfaceMethodIfProxy() until needed.
DCHECK(!referrer->IsProxyMethod() || referrer->IsConstructor());
Thread::PoisonObjectPointersIfDebug();
// We do not need the read barrier for getting the DexCache for the initial resolved method
// lookup as both from-space and to-space copies point to the same native resolved methods array.
ArtMethod* resolved_method = referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedMethod(
method_idx, image_pointer_size_);
DCHECK(resolved_method == nullptr || !resolved_method->IsRuntimeMethod());
if (UNLIKELY(resolved_method == nullptr)) {
referrer = referrer->GetInterfaceMethodIfProxy(image_pointer_size_);
ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
StackHandleScope<2> hs(self);
Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(referrer->GetDexCache()));
Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
resolved_method = ResolveMethod<kResolveMode>(method_idx,
h_dex_cache,
h_class_loader,
referrer,
type);
} else if (kResolveMode == ResolveMode::kCheckICCEAndIAE) {
referrer = referrer->GetInterfaceMethodIfProxy(image_pointer_size_);
// Check if the invoke type matches the class type.
ObjPtr<mirror::DexCache> dex_cache = referrer->GetDexCache();
ObjPtr<mirror::ClassLoader> class_loader = referrer->GetClassLoader();
if (CheckInvokeClassMismatch</* kThrow */ true>(dex_cache, type, method_idx, class_loader)) {
DCHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
// Check access.
ObjPtr<mirror::Class> referring_class = referrer->GetDeclaringClass();
if (!referring_class->CheckResolvedMethodAccess(resolved_method->GetDeclaringClass(),
resolved_method,
dex_cache,
method_idx,
type)) {
DCHECK(Thread::Current()->IsExceptionPending());
return nullptr;
}
// Check if the invoke type matches the method type.
if (UNLIKELY(resolved_method->CheckIncompatibleClassChange(type))) {
ThrowIncompatibleClassChangeError(type,
resolved_method->GetInvokeType(),
resolved_method,
referrer);
return nullptr;
}
}
// 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::LookupResolvedField(uint32_t field_idx,
ArtMethod* referrer,
bool is_static) {
// We do not need the read barrier for getting the DexCache for the initial resolved field
// lookup as both from-space and to-space copies point to the same native resolved fields array.
ArtField* field = referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedField(
field_idx, image_pointer_size_);
if (field == nullptr) {
ObjPtr<mirror::ClassLoader> class_loader = referrer->GetDeclaringClass()->GetClassLoader();
field = LookupResolvedField(field_idx, referrer->GetDexCache(), class_loader, is_static);
}
return field;
}
inline ArtField* ClassLinker::ResolveField(uint32_t field_idx,
ArtMethod* referrer,
bool is_static) {
Thread::PoisonObjectPointersIfDebug();
// We do not need the read barrier for getting the DexCache for the initial resolved field
// lookup as both from-space and to-space copies point to the same native resolved fields array.
ArtField* resolved_field = referrer->GetDexCache<kWithoutReadBarrier>()->GetResolvedField(
field_idx, image_pointer_size_);
if (UNLIKELY(resolved_field == nullptr)) {
StackHandleScope<2> hs(Thread::Current());
ObjPtr<mirror::Class> referring_class = referrer->GetDeclaringClass();
Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(referring_class->GetClassLoader()));
resolved_field = ResolveField(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::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 <class Visitor>
inline void ClassLinker::VisitClassTables(const Visitor& visitor) {
Thread* const self = Thread::Current();
WriterMutexLock mu(self, *Locks::classlinker_classes_lock_);
for (const ClassLoaderData& data : class_loaders_) {
if (data.class_table != nullptr) {
visitor(data.class_table);
}
}
}
} // namespace art
#endif // ART_RUNTIME_CLASS_LINKER_INL_H_