1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef ART_RUNTIME_CLASS_LINKER_INL_H_
18 #define ART_RUNTIME_CLASS_LINKER_INL_H_
19
20 #include "art_field.h"
21 #include "class_linker.h"
22 #include "gc_root-inl.h"
23 #include "gc/heap-inl.h"
24 #include "obj_ptr-inl.h"
25 #include "mirror/class_loader.h"
26 #include "mirror/dex_cache-inl.h"
27 #include "mirror/iftable.h"
28 #include "mirror/object_array-inl.h"
29 #include "handle_scope-inl.h"
30 #include "scoped_thread_state_change-inl.h"
31
32 #include <atomic>
33
34 namespace art {
35
FindArrayClass(Thread * self,ObjPtr<mirror::Class> * element_class)36 inline mirror::Class* ClassLinker::FindArrayClass(Thread* self,
37 ObjPtr<mirror::Class>* element_class) {
38 for (size_t i = 0; i < kFindArrayCacheSize; ++i) {
39 // Read the cached array class once to avoid races with other threads setting it.
40 ObjPtr<mirror::Class> array_class = find_array_class_cache_[i].Read();
41 if (array_class != nullptr && array_class->GetComponentType() == *element_class) {
42 return array_class.Ptr();
43 }
44 }
45 std::string descriptor = "[";
46 std::string temp;
47 descriptor += (*element_class)->GetDescriptor(&temp);
48 StackHandleScope<2> hs(Thread::Current());
49 Handle<mirror::ClassLoader> class_loader(hs.NewHandle((*element_class)->GetClassLoader()));
50 HandleWrapperObjPtr<mirror::Class> h_element_class(hs.NewHandleWrapper(element_class));
51 ObjPtr<mirror::Class> array_class = FindClass(self, descriptor.c_str(), class_loader);
52 if (array_class != nullptr) {
53 // Benign races in storing array class and incrementing index.
54 size_t victim_index = find_array_class_cache_next_victim_;
55 find_array_class_cache_[victim_index] = GcRoot<mirror::Class>(array_class);
56 find_array_class_cache_next_victim_ = (victim_index + 1) % kFindArrayCacheSize;
57 } else {
58 // We should have a NoClassDefFoundError.
59 self->AssertPendingException();
60 }
61 return array_class.Ptr();
62 }
63
LookupResolvedType(dex::TypeIndex type_idx,ObjPtr<mirror::DexCache> dex_cache,ObjPtr<mirror::ClassLoader> class_loader)64 inline ObjPtr<mirror::Class> ClassLinker::LookupResolvedType(
65 dex::TypeIndex type_idx,
66 ObjPtr<mirror::DexCache> dex_cache,
67 ObjPtr<mirror::ClassLoader> class_loader) {
68 ObjPtr<mirror::Class> type = dex_cache->GetResolvedType(type_idx);
69 if (type == nullptr) {
70 type = Runtime::Current()->GetClassLinker()->LookupResolvedType(
71 *dex_cache->GetDexFile(), type_idx, dex_cache, class_loader);
72 }
73 return type;
74 }
75
ResolveType(dex::TypeIndex type_idx,ArtMethod * referrer)76 inline mirror::Class* ClassLinker::ResolveType(dex::TypeIndex type_idx, ArtMethod* referrer) {
77 Thread::PoisonObjectPointersIfDebug();
78 if (kIsDebugBuild) {
79 Thread::Current()->AssertNoPendingException();
80 }
81 ObjPtr<mirror::Class> resolved_type = referrer->GetDexCache()->GetResolvedType(type_idx);
82 if (UNLIKELY(resolved_type == nullptr)) {
83 StackHandleScope<2> hs(Thread::Current());
84 ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
85 Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
86 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
87 const DexFile& dex_file = *dex_cache->GetDexFile();
88 resolved_type = ResolveType(dex_file, type_idx, dex_cache, class_loader);
89 }
90 return resolved_type.Ptr();
91 }
92
GetResolvedMethod(uint32_t method_idx,ArtMethod * referrer)93 inline ArtMethod* ClassLinker::GetResolvedMethod(uint32_t method_idx, ArtMethod* referrer) {
94 ArtMethod* resolved_method = referrer->GetDexCacheResolvedMethod(method_idx, image_pointer_size_);
95 if (resolved_method == nullptr || resolved_method->IsRuntimeMethod()) {
96 return nullptr;
97 }
98 return resolved_method;
99 }
100
ResolveReferencedClassOfMethod(uint32_t method_idx,Handle<mirror::DexCache> dex_cache,Handle<mirror::ClassLoader> class_loader)101 inline mirror::Class* ClassLinker::ResolveReferencedClassOfMethod(
102 uint32_t method_idx,
103 Handle<mirror::DexCache> dex_cache,
104 Handle<mirror::ClassLoader> class_loader) {
105 // NB: We cannot simply use `GetResolvedMethod(method_idx, ...)->GetDeclaringClass()`. This is
106 // because if we did so than an invoke-super could be incorrectly dispatched in cases where
107 // GetMethodId(method_idx).class_idx_ refers to a non-interface, non-direct-superclass
108 // (super*-class?) of the referrer and the direct superclass of the referrer contains a concrete
109 // implementation of the method. If this class's implementation of the method is copied from an
110 // interface (either miranda, default or conflict) we would incorrectly assume that is what we
111 // want to invoke on, instead of the 'concrete' implementation that the direct superclass
112 // contains.
113 const DexFile* dex_file = dex_cache->GetDexFile();
114 const DexFile::MethodId& method = dex_file->GetMethodId(method_idx);
115 ObjPtr<mirror::Class> resolved_type = dex_cache->GetResolvedType(method.class_idx_);
116 if (UNLIKELY(resolved_type == nullptr)) {
117 resolved_type = ResolveType(*dex_file, method.class_idx_, dex_cache, class_loader);
118 }
119 return resolved_type.Ptr();
120 }
121
122 template <ClassLinker::ResolveMode kResolveMode>
ResolveMethod(Thread * self,uint32_t method_idx,ArtMethod * referrer,InvokeType type)123 inline ArtMethod* ClassLinker::ResolveMethod(Thread* self,
124 uint32_t method_idx,
125 ArtMethod* referrer,
126 InvokeType type) {
127 ArtMethod* resolved_method = GetResolvedMethod(method_idx, referrer);
128 Thread::PoisonObjectPointersIfDebug();
129 if (UNLIKELY(resolved_method == nullptr)) {
130 ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
131 StackHandleScope<2> hs(self);
132 Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(referrer->GetDexCache()));
133 Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
134 const DexFile* dex_file = h_dex_cache->GetDexFile();
135 resolved_method = ResolveMethod<kResolveMode>(*dex_file,
136 method_idx,
137 h_dex_cache,
138 h_class_loader,
139 referrer,
140 type);
141 }
142 // Note: We cannot check here to see whether we added the method to the cache. It
143 // might be an erroneous class, which results in it being hidden from us.
144 return resolved_method;
145 }
146
LookupResolvedField(uint32_t field_idx,ArtMethod * referrer,bool is_static)147 inline ArtField* ClassLinker::LookupResolvedField(uint32_t field_idx,
148 ArtMethod* referrer,
149 bool is_static) {
150 ObjPtr<mirror::DexCache> dex_cache = referrer->GetDexCache();
151 ArtField* field = dex_cache->GetResolvedField(field_idx, image_pointer_size_);
152 if (field == nullptr) {
153 field = LookupResolvedField(field_idx, dex_cache, referrer->GetClassLoader(), is_static);
154 }
155 return field;
156 }
157
ResolveField(uint32_t field_idx,ArtMethod * referrer,bool is_static)158 inline ArtField* ClassLinker::ResolveField(uint32_t field_idx,
159 ArtMethod* referrer,
160 bool is_static) {
161 Thread::PoisonObjectPointersIfDebug();
162 ObjPtr<mirror::Class> declaring_class = referrer->GetDeclaringClass();
163 ArtField* resolved_field =
164 referrer->GetDexCache()->GetResolvedField(field_idx, image_pointer_size_);
165 if (UNLIKELY(resolved_field == nullptr)) {
166 StackHandleScope<2> hs(Thread::Current());
167 Handle<mirror::DexCache> dex_cache(hs.NewHandle(referrer->GetDexCache()));
168 Handle<mirror::ClassLoader> class_loader(hs.NewHandle(declaring_class->GetClassLoader()));
169 const DexFile& dex_file = *dex_cache->GetDexFile();
170 resolved_field = ResolveField(dex_file, field_idx, dex_cache, class_loader, is_static);
171 // Note: We cannot check here to see whether we added the field to the cache. The type
172 // might be an erroneous class, which results in it being hidden from us.
173 }
174 return resolved_field;
175 }
176
GetClassRoot(ClassRoot class_root)177 inline mirror::Class* ClassLinker::GetClassRoot(ClassRoot class_root) {
178 DCHECK(!class_roots_.IsNull());
179 mirror::ObjectArray<mirror::Class>* class_roots = class_roots_.Read();
180 ObjPtr<mirror::Class> klass = class_roots->Get(class_root);
181 DCHECK(klass != nullptr);
182 return klass.Ptr();
183 }
184
185 template<ReadBarrierOption kReadBarrierOption>
FindMethodForProxy(ObjPtr<mirror::Class> proxy_class,ArtMethod * proxy_method)186 ArtMethod* ClassLinker::FindMethodForProxy(ObjPtr<mirror::Class> proxy_class,
187 ArtMethod* proxy_method) {
188 DCHECK(proxy_class->IsProxyClass());
189 DCHECK(proxy_method->IsProxyMethod());
190 {
191 Thread* const self = Thread::Current();
192 ReaderMutexLock mu(self, *Locks::dex_lock_);
193 // Locate the dex cache of the original interface/Object
194 for (const DexCacheData& data : dex_caches_) {
195 if (!self->IsJWeakCleared(data.weak_root) &&
196 proxy_method->HasSameDexCacheResolvedMethods(data.resolved_methods,
197 image_pointer_size_)) {
198 ObjPtr<mirror::DexCache> dex_cache =
199 ObjPtr<mirror::DexCache>::DownCast(self->DecodeJObject(data.weak_root));
200 if (dex_cache != nullptr) {
201 ArtMethod* resolved_method = dex_cache->GetResolvedMethod(
202 proxy_method->GetDexMethodIndex(), image_pointer_size_);
203 CHECK(resolved_method != nullptr);
204 return resolved_method;
205 }
206 }
207 }
208 }
209 LOG(FATAL) << "Didn't find dex cache for " << proxy_class->PrettyClass() << " "
210 << proxy_method->PrettyMethod();
211 UNREACHABLE();
212 }
213
214 } // namespace art
215
216 #endif // ART_RUNTIME_CLASS_LINKER_INL_H_
217