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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_MIRROR_CLASS_INL_H_
18 #define ART_RUNTIME_MIRROR_CLASS_INL_H_
19 
20 #include "class.h"
21 
22 #include "art_field.h"
23 #include "art_method.h"
24 #include "base/array_slice.h"
25 #include "base/iteration_range.h"
26 #include "base/length_prefixed_array.h"
27 #include "base/stride_iterator.h"
28 #include "base/utils.h"
29 #include "class_linker.h"
30 #include "class_loader.h"
31 #include "common_throws.h"
32 #include "dex/class_accessor-inl.h"
33 #include "dex/dex_file-inl.h"
34 #include "dex/invoke_type.h"
35 #include "dex_cache.h"
36 #include "hidden_api.h"
37 #include "iftable-inl.h"
38 #include "imtable.h"
39 #include "object-inl.h"
40 #include "read_barrier-inl.h"
41 #include "runtime.h"
42 #include "string.h"
43 #include "subtype_check.h"
44 #include "thread-current-inl.h"
45 
46 namespace art HIDDEN {
47 namespace mirror {
48 
49 template<VerifyObjectFlags kVerifyFlags>
GetObjectSize()50 inline uint32_t Class::GetObjectSize() {
51   // Note: Extra parentheses to avoid the comma being interpreted as macro parameter separator.
52   DCHECK((!IsVariableSize<kVerifyFlags>())) << "class=" << PrettyTypeOf();
53   return GetField32(ObjectSizeOffset());
54 }
55 
56 template<VerifyObjectFlags kVerifyFlags>
GetObjectSizeAllocFastPath()57 inline uint32_t Class::GetObjectSizeAllocFastPath() {
58   // Note: Extra parentheses to avoid the comma being interpreted as macro parameter separator.
59   DCHECK((!IsVariableSize<kVerifyFlags>())) << "class=" << PrettyTypeOf();
60   return GetField32(ObjectSizeAllocFastPathOffset());
61 }
62 
63 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetSuperClass()64 inline ObjPtr<Class> Class::GetSuperClass() {
65   // Can only get super class for loaded classes (hack for when runtime is
66   // initializing)
67   DCHECK(IsLoaded<kVerifyFlags>() ||
68          IsErroneous<kVerifyFlags>() ||
69          !Runtime::Current()->IsStarted()) << IsLoaded();
70   return GetFieldObject<Class, kVerifyFlags, kReadBarrierOption>(
71       OFFSET_OF_OBJECT_MEMBER(Class, super_class_));
72 }
73 
SetSuperClass(ObjPtr<Class> new_super_class)74 inline void Class::SetSuperClass(ObjPtr<Class> new_super_class) {
75   // Super class is assigned once, except during class linker initialization.
76   if (kIsDebugBuild) {
77     ObjPtr<Class> old_super_class =
78         GetFieldObject<Class>(OFFSET_OF_OBJECT_MEMBER(Class, super_class_));
79     DCHECK(old_super_class == nullptr || old_super_class == new_super_class);
80   }
81   DCHECK(new_super_class != nullptr);
82   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
83       OFFSET_OF_OBJECT_MEMBER(Class, super_class_), new_super_class);
84 }
85 
HasSuperClass()86 inline bool Class::HasSuperClass() {
87   // No read barrier is needed for comparing with null. See ReadBarrierOption.
88   return GetSuperClass<kDefaultVerifyFlags, kWithoutReadBarrier>() != nullptr;
89 }
90 
91 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetClassLoader()92 inline ObjPtr<ClassLoader> Class::GetClassLoader() {
93   return GetFieldObject<ClassLoader, kVerifyFlags, kReadBarrierOption>(
94       OFFSET_OF_OBJECT_MEMBER(Class, class_loader_));
95 }
96 
97 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetExtData()98 inline ObjPtr<ClassExt> Class::GetExtData() {
99   return GetFieldObject<ClassExt, kVerifyFlags, kReadBarrierOption>(
100       OFFSET_OF_OBJECT_MEMBER(Class, ext_data_));
101 }
102 
103 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetDexCache()104 inline ObjPtr<DexCache> Class::GetDexCache() {
105   return GetFieldObject<DexCache, kVerifyFlags, kReadBarrierOption>(
106       OFFSET_OF_OBJECT_MEMBER(Class, dex_cache_));
107 }
108 
GetCopiedMethodsStartOffset()109 inline uint32_t Class::GetCopiedMethodsStartOffset() {
110   // Object::GetFieldShort returns an int16_t value, but
111   // Class::copied_methods_offset_ is an uint16_t value; cast the
112   // latter to uint16_t before returning it as an uint32_t value, so
113   // that uint16_t values between 2^15 and 2^16-1 are correctly
114   // handled.
115   return static_cast<uint16_t>(
116       GetFieldShort(OFFSET_OF_OBJECT_MEMBER(Class, copied_methods_offset_)));
117 }
118 
GetDirectMethodsStartOffset()119 inline uint32_t Class::GetDirectMethodsStartOffset() {
120   return 0;
121 }
122 
GetVirtualMethodsStartOffset()123 inline uint32_t Class::GetVirtualMethodsStartOffset() {
124   // Object::GetFieldShort returns an int16_t value, but
125   // Class::virtual_method_offset_ is an uint16_t value; cast the
126   // latter to uint16_t before returning it as an uint32_t value, so
127   // that uint16_t values between 2^15 and 2^16-1 are correctly
128   // handled.
129   return static_cast<uint16_t>(
130       GetFieldShort(OFFSET_OF_OBJECT_MEMBER(Class, virtual_methods_offset_)));
131 }
132 
133 template<VerifyObjectFlags kVerifyFlags>
GetDirectMethodsSlice(PointerSize pointer_size)134 inline ArraySlice<ArtMethod> Class::GetDirectMethodsSlice(PointerSize pointer_size) {
135   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
136   return GetDirectMethodsSliceUnchecked(pointer_size);
137 }
138 
GetDirectMethodsSliceUnchecked(PointerSize pointer_size)139 inline ArraySlice<ArtMethod> Class::GetDirectMethodsSliceUnchecked(PointerSize pointer_size) {
140   return GetMethodsSliceRangeUnchecked(GetMethodsPtr(),
141                                        pointer_size,
142                                        GetDirectMethodsStartOffset(),
143                                        GetVirtualMethodsStartOffset());
144 }
145 
146 template<VerifyObjectFlags kVerifyFlags>
GetDeclaredMethodsSlice(PointerSize pointer_size)147 inline ArraySlice<ArtMethod> Class::GetDeclaredMethodsSlice(PointerSize pointer_size) {
148   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
149   return GetDeclaredMethodsSliceUnchecked(pointer_size);
150 }
151 
GetDeclaredMethodsSliceUnchecked(PointerSize pointer_size)152 inline ArraySlice<ArtMethod> Class::GetDeclaredMethodsSliceUnchecked(PointerSize pointer_size) {
153   return GetMethodsSliceRangeUnchecked(GetMethodsPtr(),
154                                        pointer_size,
155                                        GetDirectMethodsStartOffset(),
156                                        GetCopiedMethodsStartOffset());
157 }
158 
159 template<VerifyObjectFlags kVerifyFlags>
GetDeclaredVirtualMethodsSlice(PointerSize pointer_size)160 inline ArraySlice<ArtMethod> Class::GetDeclaredVirtualMethodsSlice(PointerSize pointer_size) {
161   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
162   return GetDeclaredVirtualMethodsSliceUnchecked(pointer_size);
163 }
164 
GetDeclaredVirtualMethodsSliceUnchecked(PointerSize pointer_size)165 inline ArraySlice<ArtMethod> Class::GetDeclaredVirtualMethodsSliceUnchecked(
166     PointerSize pointer_size) {
167   return GetMethodsSliceRangeUnchecked(GetMethodsPtr(),
168                                        pointer_size,
169                                        GetVirtualMethodsStartOffset(),
170                                        GetCopiedMethodsStartOffset());
171 }
172 
173 template<VerifyObjectFlags kVerifyFlags>
GetVirtualMethodsSlice(PointerSize pointer_size)174 inline ArraySlice<ArtMethod> Class::GetVirtualMethodsSlice(PointerSize pointer_size) {
175   DCHECK(IsLoaded() || IsErroneous());
176   return GetVirtualMethodsSliceUnchecked(pointer_size);
177 }
178 
GetVirtualMethodsSliceUnchecked(PointerSize pointer_size)179 inline ArraySlice<ArtMethod> Class::GetVirtualMethodsSliceUnchecked(PointerSize pointer_size) {
180   LengthPrefixedArray<ArtMethod>* methods = GetMethodsPtr();
181   return GetMethodsSliceRangeUnchecked(methods,
182                                        pointer_size,
183                                        GetVirtualMethodsStartOffset(),
184                                        NumMethods(methods));
185 }
186 
187 template<VerifyObjectFlags kVerifyFlags>
GetCopiedMethodsSlice(PointerSize pointer_size)188 inline ArraySlice<ArtMethod> Class::GetCopiedMethodsSlice(PointerSize pointer_size) {
189   DCHECK(IsLoaded() || IsErroneous());
190   return GetCopiedMethodsSliceUnchecked(pointer_size);
191 }
192 
GetCopiedMethodsSliceUnchecked(PointerSize pointer_size)193 inline ArraySlice<ArtMethod> Class::GetCopiedMethodsSliceUnchecked(PointerSize pointer_size) {
194   LengthPrefixedArray<ArtMethod>* methods = GetMethodsPtr();
195   return GetMethodsSliceRangeUnchecked(methods,
196                                        pointer_size,
197                                        GetCopiedMethodsStartOffset(),
198                                        NumMethods(methods));
199 }
200 
GetMethodsPtr()201 inline LengthPrefixedArray<ArtMethod>* Class::GetMethodsPtr() {
202   return reinterpret_cast<LengthPrefixedArray<ArtMethod>*>(
203       static_cast<uintptr_t>(GetField64(OFFSET_OF_OBJECT_MEMBER(Class, methods_))));
204 }
205 
206 template<VerifyObjectFlags kVerifyFlags>
GetMethodsSlice(PointerSize pointer_size)207 inline ArraySlice<ArtMethod> Class::GetMethodsSlice(PointerSize pointer_size) {
208   DCHECK(IsLoaded() || IsErroneous());
209   LengthPrefixedArray<ArtMethod>* methods = GetMethodsPtr();
210   return GetMethodsSliceRangeUnchecked(methods, pointer_size, 0, NumMethods(methods));
211 }
212 
GetMethodsSliceRangeUnchecked(LengthPrefixedArray<ArtMethod> * methods,PointerSize pointer_size,uint32_t start_offset,uint32_t end_offset)213 inline ArraySlice<ArtMethod> Class::GetMethodsSliceRangeUnchecked(
214     LengthPrefixedArray<ArtMethod>* methods,
215     PointerSize pointer_size,
216     uint32_t start_offset,
217     uint32_t end_offset) {
218   DCHECK_LE(start_offset, end_offset);
219   DCHECK_LE(end_offset, NumMethods(methods));
220   uint32_t size = end_offset - start_offset;
221   if (size == 0u) {
222     return ArraySlice<ArtMethod>();
223   }
224   DCHECK(methods != nullptr);
225   DCHECK_LE(end_offset, methods->size());
226   size_t method_size = ArtMethod::Size(pointer_size);
227   size_t method_alignment = ArtMethod::Alignment(pointer_size);
228   ArraySlice<ArtMethod> slice(&methods->At(0u, method_size, method_alignment),
229                               methods->size(),
230                               method_size);
231   return slice.SubArray(start_offset, size);
232 }
233 
NumMethods()234 inline uint32_t Class::NumMethods() {
235   return NumMethods(GetMethodsPtr());
236 }
237 
NumMethods(LengthPrefixedArray<ArtMethod> * methods)238 inline uint32_t Class::NumMethods(LengthPrefixedArray<ArtMethod>* methods) {
239   return (methods == nullptr) ? 0 : methods->size();
240 }
241 
GetDirectMethodUnchecked(size_t i,PointerSize pointer_size)242 inline ArtMethod* Class::GetDirectMethodUnchecked(size_t i, PointerSize pointer_size) {
243   CheckPointerSize(pointer_size);
244   return &GetDirectMethodsSliceUnchecked(pointer_size)[i];
245 }
246 
GetDirectMethod(size_t i,PointerSize pointer_size)247 inline ArtMethod* Class::GetDirectMethod(size_t i, PointerSize pointer_size) {
248   CheckPointerSize(pointer_size);
249   return &GetDirectMethodsSlice(pointer_size)[i];
250 }
251 
SetMethodsPtr(LengthPrefixedArray<ArtMethod> * new_methods,uint32_t num_direct,uint32_t num_virtual)252 inline void Class::SetMethodsPtr(LengthPrefixedArray<ArtMethod>* new_methods,
253                                  uint32_t num_direct,
254                                  uint32_t num_virtual) {
255   DCHECK(GetMethodsPtr() == nullptr);
256   SetMethodsPtrUnchecked(new_methods, num_direct, num_virtual);
257 }
258 
259 
SetMethodsPtrUnchecked(LengthPrefixedArray<ArtMethod> * new_methods,uint32_t num_direct,uint32_t num_virtual)260 inline void Class::SetMethodsPtrUnchecked(LengthPrefixedArray<ArtMethod>* new_methods,
261                                           uint32_t num_direct,
262                                           uint32_t num_virtual) {
263   DCHECK_LE(num_direct + num_virtual, (new_methods == nullptr) ? 0 : new_methods->size());
264   SetField64<false>(OFFSET_OF_OBJECT_MEMBER(Class, methods_),
265                     static_cast<uint64_t>(reinterpret_cast<uintptr_t>(new_methods)));
266   SetFieldShort<false>(OFFSET_OF_OBJECT_MEMBER(Class, copied_methods_offset_),
267                     dchecked_integral_cast<uint16_t>(num_direct + num_virtual));
268   SetFieldShort<false>(OFFSET_OF_OBJECT_MEMBER(Class, virtual_methods_offset_),
269                        dchecked_integral_cast<uint16_t>(num_direct));
270 }
271 
272 template<VerifyObjectFlags kVerifyFlags>
GetVirtualMethod(size_t i,PointerSize pointer_size)273 inline ArtMethod* Class::GetVirtualMethod(size_t i, PointerSize pointer_size) {
274   CheckPointerSize(pointer_size);
275   DCHECK(IsResolved<kVerifyFlags>() || IsErroneous<kVerifyFlags>())
276       << Class::PrettyClass() << " status=" << GetStatus();
277   return GetVirtualMethodUnchecked(i, pointer_size);
278 }
279 
GetVirtualMethodDuringLinking(size_t i,PointerSize pointer_size)280 inline ArtMethod* Class::GetVirtualMethodDuringLinking(size_t i, PointerSize pointer_size) {
281   CheckPointerSize(pointer_size);
282   DCHECK(IsLoaded() || IsErroneous());
283   return GetVirtualMethodUnchecked(i, pointer_size);
284 }
285 
GetVirtualMethodUnchecked(size_t i,PointerSize pointer_size)286 inline ArtMethod* Class::GetVirtualMethodUnchecked(size_t i, PointerSize pointer_size) {
287   CheckPointerSize(pointer_size);
288   return &GetVirtualMethodsSliceUnchecked(pointer_size)[i];
289 }
290 
291 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetVTable()292 inline ObjPtr<PointerArray> Class::GetVTable() {
293   DCHECK(IsLoaded<kVerifyFlags>() || IsErroneous<kVerifyFlags>());
294   return GetFieldObject<PointerArray, kVerifyFlags, kReadBarrierOption>(
295       OFFSET_OF_OBJECT_MEMBER(Class, vtable_));
296 }
297 
GetVTableDuringLinking()298 inline ObjPtr<PointerArray> Class::GetVTableDuringLinking() {
299   DCHECK(IsLoaded() || IsErroneous());
300   return GetFieldObject<PointerArray>(OFFSET_OF_OBJECT_MEMBER(Class, vtable_));
301 }
302 
SetVTable(ObjPtr<PointerArray> new_vtable)303 inline void Class::SetVTable(ObjPtr<PointerArray> new_vtable) {
304   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
305       OFFSET_OF_OBJECT_MEMBER(Class, vtable_), new_vtable);
306 }
307 
308 template<VerifyObjectFlags kVerifyFlags>
ShouldHaveImt()309 inline bool Class::ShouldHaveImt() {
310   return ShouldHaveEmbeddedVTable<kVerifyFlags>();
311 }
312 
313 template<VerifyObjectFlags kVerifyFlags>
ShouldHaveEmbeddedVTable()314 inline bool Class::ShouldHaveEmbeddedVTable() {
315   return IsInstantiable<kVerifyFlags>();
316 }
317 
HasVTable()318 inline bool Class::HasVTable() {
319   // No read barrier is needed for comparing with null. See ReadBarrierOption.
320   return GetVTable<kDefaultVerifyFlags, kWithoutReadBarrier>() != nullptr ||
321          ShouldHaveEmbeddedVTable();
322 }
323 
324 template<VerifyObjectFlags kVerifyFlags>
GetVTableLength()325 inline int32_t Class::GetVTableLength() {
326   if (ShouldHaveEmbeddedVTable<kVerifyFlags>()) {
327     return GetEmbeddedVTableLength();
328   }
329   // We do not need a read barrier here as the length is constant,
330   // both from-space and to-space vtables shall yield the same result.
331   ObjPtr<PointerArray> vtable = GetVTable<kVerifyFlags, kWithoutReadBarrier>();
332   return vtable != nullptr ? vtable->GetLength() : 0;
333 }
334 
335 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetVTableEntry(uint32_t i,PointerSize pointer_size)336 inline ArtMethod* Class::GetVTableEntry(uint32_t i, PointerSize pointer_size) {
337   if (ShouldHaveEmbeddedVTable<kVerifyFlags>()) {
338     return GetEmbeddedVTableEntry(i, pointer_size);
339   }
340   ObjPtr<PointerArray> vtable = GetVTable<kVerifyFlags, kReadBarrierOption>();
341   DCHECK(vtable != nullptr);
342   return vtable->GetElementPtrSize<ArtMethod*, kVerifyFlags>(i, pointer_size);
343 }
344 
345 template<VerifyObjectFlags kVerifyFlags>
GetEmbeddedVTableLength()346 inline int32_t Class::GetEmbeddedVTableLength() {
347   return GetField32<kVerifyFlags>(MemberOffset(EmbeddedVTableLengthOffset()));
348 }
349 
SetEmbeddedVTableLength(int32_t len)350 inline void Class::SetEmbeddedVTableLength(int32_t len) {
351   SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
352       MemberOffset(EmbeddedVTableLengthOffset()), len);
353 }
354 
GetImt(PointerSize pointer_size)355 inline ImTable* Class::GetImt(PointerSize pointer_size) {
356   return GetFieldPtrWithSize<ImTable*>(ImtPtrOffset(pointer_size), pointer_size);
357 }
358 
SetImt(ImTable * imt,PointerSize pointer_size)359 inline void Class::SetImt(ImTable* imt, PointerSize pointer_size) {
360   return SetFieldPtrWithSize</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
361       ImtPtrOffset(pointer_size), imt, pointer_size);
362 }
363 
EmbeddedVTableEntryOffset(uint32_t i,PointerSize pointer_size)364 inline MemberOffset Class::EmbeddedVTableEntryOffset(uint32_t i, PointerSize pointer_size) {
365   return MemberOffset(
366       EmbeddedVTableOffset(pointer_size).Uint32Value() + i * VTableEntrySize(pointer_size));
367 }
368 
GetEmbeddedVTableEntry(uint32_t i,PointerSize pointer_size)369 inline ArtMethod* Class::GetEmbeddedVTableEntry(uint32_t i, PointerSize pointer_size) {
370   return GetFieldPtrWithSize<ArtMethod*>(EmbeddedVTableEntryOffset(i, pointer_size), pointer_size);
371 }
372 
SetEmbeddedVTableEntryUnchecked(uint32_t i,ArtMethod * method,PointerSize pointer_size)373 inline void Class::SetEmbeddedVTableEntryUnchecked(
374     uint32_t i, ArtMethod* method, PointerSize pointer_size) {
375   SetFieldPtrWithSize</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
376       EmbeddedVTableEntryOffset(i, pointer_size), method, pointer_size);
377 }
378 
SetEmbeddedVTableEntry(uint32_t i,ArtMethod * method,PointerSize pointer_size)379 inline void Class::SetEmbeddedVTableEntry(uint32_t i, ArtMethod* method, PointerSize pointer_size) {
380   ObjPtr<PointerArray> vtable = GetVTableDuringLinking();
381   CHECK_EQ(method, vtable->GetElementPtrSize<ArtMethod*>(i, pointer_size));
382   SetEmbeddedVTableEntryUnchecked(i, method, pointer_size);
383 }
384 
Implements(ObjPtr<Class> klass)385 inline bool Class::Implements(ObjPtr<Class> klass) {
386   DCHECK(klass != nullptr);
387   DCHECK(klass->IsInterface()) << PrettyClass();
388   // All interfaces implemented directly and by our superclass, and
389   // recursively all super-interfaces of those interfaces, are listed
390   // in iftable_, so we can just do a linear scan through that.
391   int32_t iftable_count = GetIfTableCount();
392   ObjPtr<IfTable> iftable = GetIfTable();
393   for (int32_t i = 0; i < iftable_count; i++) {
394     if (iftable->GetInterface(i) == klass) {
395       return true;
396     }
397   }
398   return false;
399 }
400 
401 template<VerifyObjectFlags kVerifyFlags>
IsVariableSize()402 inline bool Class::IsVariableSize() {
403   // Classes, arrays, and strings vary in size, and so the object_size_ field cannot
404   // be used to Get their instance size
405   return IsClassClass<kVerifyFlags>() ||
406          IsArrayClass<kVerifyFlags>() ||
407          IsStringClass<kVerifyFlags>();
408 }
409 
SetObjectSize(uint32_t new_object_size)410 inline void Class::SetObjectSize(uint32_t new_object_size) {
411   DCHECK(!IsVariableSize());
412   // Not called within a transaction.
413   return SetField32<false>(OFFSET_OF_OBJECT_MEMBER(Class, object_size_), new_object_size);
414 }
415 
416 template<typename T>
IsDiscoverable(bool public_only,const hiddenapi::AccessContext & access_context,T * member)417 inline bool Class::IsDiscoverable(bool public_only,
418                                   const hiddenapi::AccessContext& access_context,
419                                   T* member) {
420   if (public_only && ((member->GetAccessFlags() & kAccPublic) == 0)) {
421     return false;
422   }
423 
424   return !hiddenapi::ShouldDenyAccessToMember(
425       member, access_context, hiddenapi::AccessMethod::kCheckWithPolicy);
426 }
427 
428 // Determine whether "this" is assignable from "src", where both of these
429 // are array classes.
430 //
431 // Consider an array class, e.g. Y[][], where Y is a subclass of X.
432 //   Y[][]            = Y[][] --> true (identity)
433 //   X[][]            = Y[][] --> true (element superclass)
434 //   Y                = Y[][] --> false
435 //   Y[]              = Y[][] --> false
436 //   Object           = Y[][] --> true (everything is an object)
437 //   Object[]         = Y[][] --> true
438 //   Object[][]       = Y[][] --> true
439 //   Object[][][]     = Y[][] --> false (too many []s)
440 //   Serializable     = Y[][] --> true (all arrays are Serializable)
441 //   Serializable[]   = Y[][] --> true
442 //   Serializable[][] = Y[][] --> false (unless Y is Serializable)
443 //
444 // Don't forget about primitive types.
445 //   Object[]         = int[] --> false
446 //
IsArrayAssignableFromArray(ObjPtr<Class> src)447 inline bool Class::IsArrayAssignableFromArray(ObjPtr<Class> src) {
448   DCHECK(IsArrayClass()) << PrettyClass();
449   DCHECK(src->IsArrayClass()) << src->PrettyClass();
450   return GetComponentType()->IsAssignableFrom(src->GetComponentType());
451 }
452 
IsAssignableFromArray(ObjPtr<Class> src)453 inline bool Class::IsAssignableFromArray(ObjPtr<Class> src) {
454   DCHECK(!IsInterface()) << PrettyClass();  // handled first in IsAssignableFrom
455   DCHECK(src->IsArrayClass()) << src->PrettyClass();
456   if (!IsArrayClass()) {
457     // If "this" is not also an array, it must be Object.
458     // src's super should be java_lang_Object, since it is an array.
459     ObjPtr<Class> java_lang_Object = src->GetSuperClass();
460     DCHECK(java_lang_Object != nullptr) << src->PrettyClass();
461     DCHECK(java_lang_Object->GetSuperClass() == nullptr) << src->PrettyClass();
462     return this == java_lang_Object;
463   }
464   return IsArrayAssignableFromArray(src);
465 }
466 
467 template <bool throw_on_failure>
ResolvedFieldAccessTest(ObjPtr<Class> access_to,ArtField * field,ObjPtr<DexCache> dex_cache,uint32_t field_idx)468 inline bool Class::ResolvedFieldAccessTest(ObjPtr<Class> access_to,
469                                            ArtField* field,
470                                            ObjPtr<DexCache> dex_cache,
471                                            uint32_t field_idx) {
472   DCHECK(dex_cache != nullptr);
473   if (UNLIKELY(!this->CanAccess(access_to))) {
474     // The referrer class can't access the field's declaring class but may still be able
475     // to access the field if the FieldId specifies an accessible subclass of the declaring
476     // class rather than the declaring class itself.
477     dex::TypeIndex class_idx = dex_cache->GetDexFile()->GetFieldId(field_idx).class_idx_;
478     // The referenced class has already been resolved with the field, but may not be in the dex
479     // cache. Use LookupResolveType here to search the class table if it is not in the dex cache.
480     // should be no thread suspension due to the class being resolved.
481     ObjPtr<Class> dex_access_to = Runtime::Current()->GetClassLinker()->LookupResolvedType(
482         class_idx,
483         dex_cache,
484         GetClassLoader());
485     DCHECK(dex_access_to != nullptr);
486     if (UNLIKELY(!this->CanAccess(dex_access_to))) {
487       if (throw_on_failure) {
488         ThrowIllegalAccessErrorClass(this, dex_access_to);
489       }
490       return false;
491     }
492   }
493   if (LIKELY(this->CanAccessMember(access_to, field->GetAccessFlags()))) {
494     return true;
495   }
496   if (throw_on_failure) {
497     ThrowIllegalAccessErrorField(this, field);
498   }
499   return false;
500 }
501 
CanAccessResolvedField(ObjPtr<Class> access_to,ArtField * field,ObjPtr<DexCache> dex_cache,uint32_t field_idx)502 inline bool Class::CanAccessResolvedField(ObjPtr<Class> access_to,
503                                           ArtField* field,
504                                           ObjPtr<DexCache> dex_cache,
505                                           uint32_t field_idx) {
506   return ResolvedFieldAccessTest<false>(access_to, field, dex_cache, field_idx);
507 }
508 
CheckResolvedFieldAccess(ObjPtr<Class> access_to,ArtField * field,ObjPtr<DexCache> dex_cache,uint32_t field_idx)509 inline bool Class::CheckResolvedFieldAccess(ObjPtr<Class> access_to,
510                                             ArtField* field,
511                                             ObjPtr<DexCache> dex_cache,
512                                             uint32_t field_idx) {
513   return ResolvedFieldAccessTest<true>(access_to, field, dex_cache, field_idx);
514 }
515 
IsObsoleteVersionOf(ObjPtr<Class> klass)516 inline bool Class::IsObsoleteVersionOf(ObjPtr<Class> klass) {
517   DCHECK(!klass->IsObsoleteObject()) << klass->PrettyClass() << " is obsolete!";
518   if (LIKELY(!IsObsoleteObject())) {
519     return false;
520   }
521   ObjPtr<Class> current(klass);
522   do {
523     if (UNLIKELY(current == this)) {
524       return true;
525     } else {
526       current = current->GetObsoleteClass();
527     }
528   } while (!current.IsNull());
529   return false;
530 }
531 
IsSubClass(ObjPtr<Class> klass)532 inline bool Class::IsSubClass(ObjPtr<Class> klass) {
533   // Since the SubtypeCheck::IsSubtypeOf needs to lookup the Depth,
534   // it is always O(Depth) in terms of speed to do the check.
535   //
536   // So always do the "slow" linear scan in normal release builds.
537   //
538   // Future note: If we could have the depth in O(1) we could use the 'fast'
539   // method instead as it avoids a loop and a read barrier.
540   bool result = false;
541   DCHECK(!IsInterface()) << PrettyClass();
542   DCHECK(!IsArrayClass()) << PrettyClass();
543   ObjPtr<Class> current = this;
544   do {
545     if (current == klass) {
546       result = true;
547       break;
548     }
549     current = current->GetSuperClass();
550   } while (current != nullptr);
551 
552   if (kIsDebugBuild && kBitstringSubtypeCheckEnabled) {
553     ObjPtr<mirror::Class> dis(this);
554 
555     SubtypeCheckInfo::Result sc_result = SubtypeCheck<ObjPtr<Class>>::IsSubtypeOf(dis, klass);
556     if (sc_result != SubtypeCheckInfo::kUnknownSubtypeOf) {
557       // Note: The "kUnknownSubTypeOf" can be avoided if and only if:
558       //   SubtypeCheck::EnsureInitialized(source)
559       //       happens-before source.IsSubClass(target)
560       //   SubtypeCheck::EnsureAssigned(target).GetState() == Assigned
561       //       happens-before source.IsSubClass(target)
562       //
563       // When code generated by optimizing compiler executes this operation, both
564       // happens-before are guaranteed, so there is no fallback code there.
565       SubtypeCheckInfo::Result expected_result =
566           result ? SubtypeCheckInfo::kSubtypeOf : SubtypeCheckInfo::kNotSubtypeOf;
567       DCHECK_EQ(expected_result, sc_result)
568           << "source: " << PrettyClass() << "target: " << klass->PrettyClass();
569     }
570   }
571 
572   return result;
573 }
574 
FindVirtualMethodForInterface(ArtMethod * method,PointerSize pointer_size)575 inline ArtMethod* Class::FindVirtualMethodForInterface(ArtMethod* method,
576                                                        PointerSize pointer_size) {
577   ObjPtr<Class> declaring_class = method->GetDeclaringClass();
578   DCHECK(declaring_class != nullptr) << PrettyClass();
579   if (UNLIKELY(!declaring_class->IsInterface())) {
580     DCHECK(declaring_class->IsObjectClass()) << method->PrettyMethod();
581     DCHECK(method->IsPublic() && !method->IsStatic());
582     return FindVirtualMethodForVirtual(method, pointer_size);
583   }
584   DCHECK(!method->IsCopied());
585   // TODO cache to improve lookup speed
586   const int32_t iftable_count = GetIfTableCount();
587   ObjPtr<IfTable> iftable = GetIfTable();
588   for (int32_t i = 0; i < iftable_count; i++) {
589     if (iftable->GetInterface(i) == declaring_class) {
590       return iftable->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>(
591           method->GetMethodIndex(), pointer_size);
592     }
593   }
594   return nullptr;
595 }
596 
FindVirtualMethodForVirtual(ArtMethod * method,PointerSize pointer_size)597 inline ArtMethod* Class::FindVirtualMethodForVirtual(ArtMethod* method, PointerSize pointer_size) {
598   // Only miranda or default methods may come from interfaces and be used as a virtual.
599   DCHECK(!method->GetDeclaringClass()->IsInterface() || method->IsDefault() || method->IsMiranda());
600   DCHECK(method->GetDeclaringClass()->IsAssignableFrom(this))
601       << "Method " << method->PrettyMethod()
602       << " is not declared in " << PrettyDescriptor() << " or its super classes";
603   // The argument method may from a super class.
604   // Use the index to a potentially overridden one for this instance's class.
605   return GetVTableEntry(method->GetMethodIndex(), pointer_size);
606 }
607 
FindVirtualMethodForSuper(ArtMethod * method,PointerSize pointer_size)608 inline ArtMethod* Class::FindVirtualMethodForSuper(ArtMethod* method, PointerSize pointer_size) {
609   DCHECK(!method->GetDeclaringClass()->IsInterface());
610   DCHECK(method->GetDeclaringClass()->IsAssignableFrom(this))
611       << "Method " << method->PrettyMethod()
612       << " is not declared in " << PrettyDescriptor() << " or its super classes";
613   return GetSuperClass()->GetVTableEntry(method->GetMethodIndex(), pointer_size);
614 }
615 
FindVirtualMethodForVirtualOrInterface(ArtMethod * method,PointerSize pointer_size)616 inline ArtMethod* Class::FindVirtualMethodForVirtualOrInterface(ArtMethod* method,
617                                                                 PointerSize pointer_size) {
618   if (method->IsDirect()) {
619     return method;
620   }
621   if (method->GetDeclaringClass()->IsInterface() && !method->IsCopied()) {
622     return FindVirtualMethodForInterface(method, pointer_size);
623   }
624   return FindVirtualMethodForVirtual(method, pointer_size);
625 }
626 
627 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetIfTable()628 inline ObjPtr<IfTable> Class::GetIfTable() {
629   ObjPtr<IfTable> ret = GetFieldObject<IfTable, kVerifyFlags, kReadBarrierOption>(IfTableOffset());
630   DCHECK(ret != nullptr) << PrettyClass(this);
631   return ret;
632 }
633 
634 template<VerifyObjectFlags kVerifyFlags>
GetIfTableCount()635 inline int32_t Class::GetIfTableCount() {
636   // We do not need a read barrier here as the length is constant,
637   // both from-space and to-space iftables shall yield the same result.
638   return GetIfTable<kVerifyFlags, kWithoutReadBarrier>()->Count();
639 }
640 
SetIfTable(ObjPtr<IfTable> new_iftable)641 inline void Class::SetIfTable(ObjPtr<IfTable> new_iftable) {
642   DCHECK(new_iftable != nullptr) << PrettyClass(this);
643   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
644       IfTableOffset(), new_iftable);
645 }
646 
GetFieldsPtr()647 inline LengthPrefixedArray<ArtField>* Class::GetFieldsPtr() {
648   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
649   return GetFieldPtr<LengthPrefixedArray<ArtField>*>(OFFSET_OF_OBJECT_MEMBER(Class, fields_));
650 }
651 
652 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetFirstReferenceInstanceFieldOffset()653 inline MemberOffset Class::GetFirstReferenceInstanceFieldOffset() {
654   ObjPtr<Class> super_class = GetSuperClass<kVerifyFlags, kReadBarrierOption>();
655   return (super_class != nullptr)
656       ? MemberOffset(RoundUp(super_class->GetObjectSize<kVerifyFlags>(), kHeapReferenceSize))
657       : ClassOffset();
658 }
659 
660 template <VerifyObjectFlags kVerifyFlags>
GetFirstReferenceStaticFieldOffset(PointerSize pointer_size)661 inline MemberOffset Class::GetFirstReferenceStaticFieldOffset(PointerSize pointer_size) {
662   DCHECK(IsResolved<kVerifyFlags>());
663   uint32_t base = sizeof(Class);  // Static fields come after the class.
664   if (ShouldHaveEmbeddedVTable<kVerifyFlags>()) {
665     // Static fields come after the embedded tables.
666     base = Class::ComputeClassSize(
667         true, GetEmbeddedVTableLength<kVerifyFlags>(), 0, 0, 0, 0, 0, 0, pointer_size);
668   }
669   return MemberOffset(base);
670 }
671 
GetFirstReferenceStaticFieldOffsetDuringLinking(PointerSize pointer_size)672 inline MemberOffset Class::GetFirstReferenceStaticFieldOffsetDuringLinking(
673     PointerSize pointer_size) {
674   DCHECK(IsLoaded());
675   uint32_t base = sizeof(Class);  // Static fields come after the class.
676   if (ShouldHaveEmbeddedVTable()) {
677     // Static fields come after the embedded tables.
678     base = Class::ComputeClassSize(
679         true, GetVTableDuringLinking()->GetLength(), 0, 0, 0, 0, 0, 0, pointer_size);
680   }
681   return MemberOffset(base);
682 }
683 
SetFieldsPtr(LengthPrefixedArray<ArtField> * new_fields)684 inline void Class::SetFieldsPtr(LengthPrefixedArray<ArtField>* new_fields) {
685   DCHECK(GetFieldsPtrUnchecked() == nullptr);
686   return SetFieldPtr<false>(OFFSET_OF_OBJECT_MEMBER(Class, fields_), new_fields);
687 }
688 
SetFieldsPtrUnchecked(LengthPrefixedArray<ArtField> * new_fields)689 inline void Class::SetFieldsPtrUnchecked(LengthPrefixedArray<ArtField>* new_fields) {
690   SetFieldPtr<false, true, kVerifyNone>(OFFSET_OF_OBJECT_MEMBER(Class, fields_), new_fields);
691 }
692 
GetFieldsPtrUnchecked()693 inline LengthPrefixedArray<ArtField>* Class::GetFieldsPtrUnchecked() {
694   return GetFieldPtr<LengthPrefixedArray<ArtField>*>(OFFSET_OF_OBJECT_MEMBER(Class, fields_));
695 }
696 
GetField(uint32_t i)697 inline ArtField* Class::GetField(uint32_t i) {
698   return &GetFieldsPtr()->At(i);
699 }
700 
701 template<VerifyObjectFlags kVerifyFlags>
GetReferenceInstanceOffsets()702 inline uint32_t Class::GetReferenceInstanceOffsets() {
703   DCHECK(IsResolved<kVerifyFlags>() || IsErroneous<kVerifyFlags>());
704   return GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, reference_instance_offsets_));
705 }
706 
SetClinitThreadId(pid_t new_clinit_thread_id)707 inline void Class::SetClinitThreadId(pid_t new_clinit_thread_id) {
708   SetField32Transaction(OFFSET_OF_OBJECT_MEMBER(Class, clinit_thread_id_), new_clinit_thread_id);
709 }
710 
711 template<VerifyObjectFlags kVerifyFlags,
712          ReadBarrierOption kReadBarrierOption>
GetName()713 inline ObjPtr<String> Class::GetName() {
714   return GetFieldObject<String, kVerifyFlags, kReadBarrierOption>(
715       OFFSET_OF_OBJECT_MEMBER(Class, name_));
716 }
717 
SetName(ObjPtr<String> name)718 inline void Class::SetName(ObjPtr<String> name) {
719   SetFieldObjectTransaction(OFFSET_OF_OBJECT_MEMBER(Class, name_), name);
720 }
721 
722 template<VerifyObjectFlags kVerifyFlags>
GetPrimitiveType()723 inline Primitive::Type Class::GetPrimitiveType() {
724   static_assert(sizeof(Primitive::Type) == sizeof(int32_t),
725                 "art::Primitive::Type and int32_t have different sizes.");
726   int32_t v32 = GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, primitive_type_));
727   Primitive::Type type = static_cast<Primitive::Type>(v32 & kPrimitiveTypeMask);
728   DCHECK_EQ(static_cast<size_t>(v32 >> kPrimitiveTypeSizeShiftShift),
729             Primitive::ComponentSizeShift(type));
730   return type;
731 }
732 
733 template<VerifyObjectFlags kVerifyFlags>
GetPrimitiveTypeSizeShift()734 inline size_t Class::GetPrimitiveTypeSizeShift() {
735   static_assert(sizeof(Primitive::Type) == sizeof(int32_t),
736                 "art::Primitive::Type and int32_t have different sizes.");
737   int32_t v32 = GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, primitive_type_));
738   size_t size_shift = static_cast<Primitive::Type>(v32 >> kPrimitiveTypeSizeShiftShift);
739   DCHECK_EQ(size_shift,
740             Primitive::ComponentSizeShift(static_cast<Primitive::Type>(v32 & kPrimitiveTypeMask)));
741   return size_shift;
742 }
743 
744 template <VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
VerifyOverflowReferenceBitmap()745 inline void Class::VerifyOverflowReferenceBitmap() {
746   // Can't reliably access super-classes during CMC compaction.
747   if (Runtime::Current() != nullptr && Runtime::Current()->GetHeap() != nullptr &&
748       Runtime::Current()->GetHeap()->IsPerformingUffdCompaction()) {
749     return;
750   }
751   CHECK(!IsVariableSize<kVerifyFlags>());
752   ObjPtr<Class> klass;
753   ObjPtr<mirror::Class> super_class;
754   size_t num_bits =
755       (RoundUp(GetObjectSize<kVerifyFlags>(), sizeof(mirror::HeapReference<mirror::Object>)) -
756        mirror::kObjectHeaderSize) /
757       sizeof(mirror::HeapReference<mirror::Object>);
758   std::vector<bool> check_bitmap(num_bits, false);
759   for (klass = this; klass != nullptr; klass = super_class) {
760     super_class = klass->GetSuperClass<kVerifyFlags, kReadBarrierOption>();
761     if (klass->NumReferenceInstanceFields<kVerifyFlags>() != 0) {
762       break;
763     }
764   }
765 
766   if (super_class != nullptr) {
767     std::vector<ObjPtr<Class>> klasses;
768     for (; klass != nullptr; klass = super_class) {
769       super_class = klass->GetSuperClass<kVerifyFlags, kReadBarrierOption>();
770       if (super_class != nullptr) {
771         klasses.push_back(klass);
772       }
773     }
774 
775     for (auto iter = klasses.rbegin(); iter != klasses.rend(); iter++) {
776       klass = *iter;
777       size_t idx = (klass->GetFirstReferenceInstanceFieldOffset<kVerifyFlags, kReadBarrierOption>()
778                         .Uint32Value() -
779                     mirror::kObjectHeaderSize) /
780                    sizeof(mirror::HeapReference<mirror::Object>);
781       uint32_t num_refs = klass->NumReferenceInstanceFields<kVerifyFlags>();
782       for (uint32_t i = 0; i < num_refs; i++) {
783         check_bitmap[idx++] = true;
784       }
785       CHECK_LE(idx, num_bits) << PrettyClass();
786     }
787   }
788 
789   uint32_t ref_offsets =
790       GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, reference_instance_offsets_));
791   CHECK_NE(ref_offsets, 0u) << PrettyClass();
792   CHECK((ref_offsets & kVisitReferencesSlowpathMask) != 0) << PrettyClass();
793   uint32_t bitmap_num_words = ref_offsets & ~kVisitReferencesSlowpathMask;
794   uint32_t* overflow_bitmap = reinterpret_cast<uint32_t*>(
795       reinterpret_cast<uint8_t*>(this) +
796       (GetClassSize<kVerifyFlags>() - bitmap_num_words * sizeof(uint32_t)));
797   for (uint32_t i = 0, field_offset = 0; i < bitmap_num_words; i++, field_offset += 32) {
798     ref_offsets = overflow_bitmap[i];
799     uint32_t check_bitmap_idx = field_offset;
800     // Confirm that all the bits in check_bitmap that ought to be set, are set.
801     while (ref_offsets != 0) {
802       if ((ref_offsets & 1) != 0) {
803         CHECK(check_bitmap[check_bitmap_idx])
804             << PrettyClass() << " i:" << i << " field_offset:" << field_offset
805             << " check_bitmap_idx:" << check_bitmap_idx << " bitmap_word:" << overflow_bitmap[i];
806         check_bitmap[check_bitmap_idx] = false;
807       }
808       ref_offsets >>= 1;
809       check_bitmap_idx++;
810     }
811   }
812   // Confirm that there is no other bit set.
813   std::ostringstream oss;
814   bool found = false;
815   for (size_t i = 0; i < check_bitmap.size(); i++) {
816     if (check_bitmap[i]) {
817       if (!found) {
818         DumpClass(oss, kDumpClassFullDetail);
819         oss << " set-bits:";
820       }
821       found = true;
822       oss << i << ",";
823     }
824   }
825   if (found) {
826     oss << " stored-bitmap:";
827     for (size_t i = 0; i < bitmap_num_words; i++) {
828       oss << overflow_bitmap[i] << ":";
829     }
830     LOG(FATAL) << oss.str();
831   }
832 }
833 
AdjustClassSizeForReferenceOffsetBitmapDuringLinking(ObjPtr<Class> klass,size_t class_size)834 inline size_t Class::AdjustClassSizeForReferenceOffsetBitmapDuringLinking(ObjPtr<Class> klass,
835                                                                           size_t class_size) {
836   if (klass->IsInstantiable()) {
837     // Find the first class with non-zero instance field count and its super-class'
838     // object-size together will tell us the required size.
839     for (ObjPtr<Class> k = klass; k != nullptr; k = k->GetSuperClass()) {
840       size_t num_reference_fields = k->NumReferenceInstanceFieldsDuringLinking();
841       if (num_reference_fields != 0) {
842         ObjPtr<Class> super = k->GetSuperClass();
843         // Leave it for mirror::Object (the class field is handled specially).
844         if (super != nullptr) {
845           // All of the fields that contain object references are guaranteed to be grouped in
846           // memory starting at an appropriately aligned address after super class object data.
847           uint32_t start_offset =
848               RoundUp(super->GetObjectSize(), sizeof(mirror::HeapReference<mirror::Object>));
849           uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) /
850                                sizeof(mirror::HeapReference<mirror::Object>);
851           if (start_bit + num_reference_fields > 31) {
852             // Alignment that maybe required at the end of static fields smaller than 32-bit.
853             class_size = RoundUp(class_size, sizeof(uint32_t));
854             // 32-bit words required for the overflow bitmap.
855             class_size += RoundUp(start_bit + num_reference_fields, 32) / 32 * sizeof(uint32_t);
856           }
857         }
858         break;
859       }
860     }
861   }
862   return class_size;
863 }
864 
ComputeClassSize(bool has_embedded_vtable,uint32_t num_vtable_entries,uint32_t num_8bit_static_fields,uint32_t num_16bit_static_fields,uint32_t num_32bit_static_fields,uint32_t num_64bit_static_fields,uint32_t num_ref_static_fields,uint32_t num_ref_bitmap_entries,PointerSize pointer_size)865 inline uint32_t Class::ComputeClassSize(bool has_embedded_vtable,
866                                         uint32_t num_vtable_entries,
867                                         uint32_t num_8bit_static_fields,
868                                         uint32_t num_16bit_static_fields,
869                                         uint32_t num_32bit_static_fields,
870                                         uint32_t num_64bit_static_fields,
871                                         uint32_t num_ref_static_fields,
872                                         uint32_t num_ref_bitmap_entries,
873                                         PointerSize pointer_size) {
874   // Space used by java.lang.Class and its instance fields.
875   uint32_t size = sizeof(Class);
876   // Space used by embedded tables.
877   if (has_embedded_vtable) {
878     size = RoundUp(size + sizeof(uint32_t), static_cast<size_t>(pointer_size));
879     size += static_cast<size_t>(pointer_size);  // size of pointer to IMT
880     size += num_vtable_entries * VTableEntrySize(pointer_size);
881   }
882 
883   // Space used by reference statics.
884   size += num_ref_static_fields * kHeapReferenceSize;
885   if (!IsAligned<8>(size) && num_64bit_static_fields > 0) {
886     uint32_t gap = 8 - (size & 0x7);
887     size += gap;  // will be padded
888     // Shuffle 4-byte fields forward.
889     while (gap >= sizeof(uint32_t) && num_32bit_static_fields != 0) {
890       --num_32bit_static_fields;
891       gap -= sizeof(uint32_t);
892     }
893     // Shuffle 2-byte fields forward.
894     while (gap >= sizeof(uint16_t) && num_16bit_static_fields != 0) {
895       --num_16bit_static_fields;
896       gap -= sizeof(uint16_t);
897     }
898     // Shuffle byte fields forward.
899     while (gap >= sizeof(uint8_t) && num_8bit_static_fields != 0) {
900       --num_8bit_static_fields;
901       gap -= sizeof(uint8_t);
902     }
903   }
904   // Guaranteed to be at least 4 byte aligned. No need for further alignments.
905   // Space used for primitive static fields.
906   size += num_8bit_static_fields * sizeof(uint8_t) + num_16bit_static_fields * sizeof(uint16_t) +
907       num_32bit_static_fields * sizeof(uint32_t) + num_64bit_static_fields * sizeof(uint64_t);
908 
909   // Space used by reference-offset bitmap.
910   if (num_ref_bitmap_entries > 0) {
911     size = RoundUp(size, sizeof(uint32_t));
912     size += num_ref_bitmap_entries * sizeof(uint32_t);
913   }
914   return size;
915 }
916 
917 template<VerifyObjectFlags kVerifyFlags>
IsClassClass()918 inline bool Class::IsClassClass() {
919   // OK to look at from-space copies since java.lang.Class.class is non-moveable
920   // (even when running without boot image, see ClassLinker::InitWithoutImage())
921   // and we're reading it for comparison only. See ReadBarrierOption.
922   ObjPtr<Class> java_lang_Class = GetClass<kVerifyFlags, kWithoutReadBarrier>();
923   return this == java_lang_Class;
924 }
925 
GetDexFile()926 inline const DexFile& Class::GetDexFile() {
927   // From-space version is the same as the to-space version since the dex file never changes.
928   // Avoiding the read barrier here is important to prevent recursive AssertToSpaceInvariant issues
929   // from PrettyTypeOf.
930   return *GetDexCache<kDefaultVerifyFlags, kWithoutReadBarrier>()->GetDexFile();
931 }
932 
GetDescriptorView()933 inline std::string_view Class::GetDescriptorView() {
934   DCHECK(!IsArrayClass());
935   DCHECK(!IsPrimitive());
936   DCHECK(!IsProxyClass());
937   return GetDexFile().GetTypeDescriptorView(GetDexTypeIndex());
938 }
939 
DescriptorEquals(std::string_view match)940 inline bool Class::DescriptorEquals(std::string_view match) {
941   ObjPtr<mirror::Class> klass = this;
942   while (klass->IsArrayClass()) {
943     if (UNLIKELY(match.empty()) || match[0] != '[') {
944       return false;
945     }
946     match.remove_prefix(1u);
947     // No read barrier needed, we're reading a chain of constant references for comparison
948     // with null. Then we follow up below with reading constant references to read constant
949     // primitive data in both proxy and non-proxy paths. See ReadBarrierOption.
950     klass = klass->GetComponentType<kDefaultVerifyFlags, kWithoutReadBarrier>();
951   }
952   if (klass->IsPrimitive()) {
953     return match.length() == 1u && match[0] == Primitive::Descriptor(klass->GetPrimitiveType())[0];
954   } else if (UNLIKELY(klass->IsProxyClass())) {
955     return klass->ProxyDescriptorEquals(match);
956   } else {
957     const DexFile& dex_file = klass->GetDexFile();
958     const dex::TypeId& type_id = dex_file.GetTypeId(klass->GetDexTypeIndex());
959     return dex_file.GetTypeDescriptorView(type_id) == match;
960   }
961 }
962 
DescriptorHash()963 inline uint32_t Class::DescriptorHash() {
964   // No read barriers needed, we're reading a chain of constant references for comparison with null
965   // and retrieval of constant primitive data. See `ReadBarrierOption` and `Class::GetDescriptor()`.
966   ObjPtr<mirror::Class> klass = this;
967   uint32_t hash = StartModifiedUtf8Hash();
968   while (klass->IsArrayClass()) {
969     klass = klass->GetComponentType<kDefaultVerifyFlags, kWithoutReadBarrier>();
970     hash = UpdateModifiedUtf8Hash(hash, '[');
971   }
972   if (UNLIKELY(klass->IsProxyClass())) {
973     hash = UpdateHashForProxyClass(hash, klass);
974   } else if (klass->IsPrimitive()) {
975     hash = UpdateModifiedUtf8Hash(hash, Primitive::Descriptor(klass->GetPrimitiveType())[0]);
976   } else {
977     const DexFile& dex_file = klass->GetDexFile();
978     const dex::TypeId& type_id = dex_file.GetTypeId(klass->GetDexTypeIndex());
979     std::string_view descriptor = dex_file.GetTypeDescriptorView(type_id);
980     hash = UpdateModifiedUtf8Hash(hash, descriptor);
981   }
982 
983   if (kIsDebugBuild) {
984     std::string temp;
985     CHECK_EQ(hash, ComputeModifiedUtf8Hash(GetDescriptor(&temp)));
986   }
987 
988   return hash;
989 }
990 
AssertInitializedOrInitializingInThread(Thread * self)991 inline void Class::AssertInitializedOrInitializingInThread(Thread* self) {
992   if (kIsDebugBuild && !IsInitialized()) {
993     CHECK(IsInitializing()) << PrettyClass() << " is not initializing: " << GetStatus();
994     CHECK_EQ(GetClinitThreadId(), self->GetTid())
995         << PrettyClass() << " is initializing in a different thread";
996   }
997 }
998 
GetProxyInterfaces()999 inline ObjPtr<ObjectArray<Class>> Class::GetProxyInterfaces() {
1000   CHECK(IsProxyClass());
1001   // First field.
1002   ArtField* field = GetField(0);
1003   DCHECK_STREQ(field->GetName(), "interfaces");
1004   MemberOffset field_offset = field->GetOffset();
1005   return GetFieldObject<ObjectArray<Class>>(field_offset);
1006 }
1007 
GetProxyThrows()1008 inline ObjPtr<ObjectArray<ObjectArray<Class>>> Class::GetProxyThrows() {
1009   CHECK(IsProxyClass());
1010   // Second field.
1011   ArtField* field = GetField(1);
1012   DCHECK_STREQ(field->GetName(), "throws");
1013   MemberOffset field_offset = field->GetOffset();
1014   return GetFieldObject<ObjectArray<ObjectArray<Class>>>(field_offset);
1015 }
1016 
IsBootStrapClassLoaded()1017 inline bool Class::IsBootStrapClassLoaded() {
1018   // No read barrier is needed for comparing with null. See ReadBarrierOption.
1019   return GetClassLoader<kDefaultVerifyFlags, kWithoutReadBarrier>() == nullptr;
1020 }
1021 
operator()1022 inline void Class::InitializeClassVisitor::operator()(ObjPtr<Object> obj,
1023                                                       size_t usable_size) const {
1024   DCHECK_LE(class_size_, usable_size);
1025   // Avoid AsClass as object is not yet in live bitmap or allocation stack.
1026   ObjPtr<Class> klass = ObjPtr<Class>::DownCast(obj);
1027   klass->SetClassSize(class_size_);
1028   klass->SetPrimitiveType(Primitive::kPrimNot);  // Default to not being primitive.
1029   klass->SetDexClassDefIndex(DexFile::kDexNoIndex16);  // Default to no valid class def index.
1030   klass->SetDexTypeIndex(dex::TypeIndex(DexFile::kDexNoIndex16));  // Default to no valid type
1031                                                                    // index.
1032   // Default to force slow path until visibly initialized.
1033   // There is no need for release store (volatile) in pre-fence visitor.
1034   klass->SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1035       ObjectSizeAllocFastPathOffset(), std::numeric_limits<uint32_t>::max());
1036 }
1037 
SetAccessFlagsDuringLinking(uint32_t new_access_flags)1038 inline void Class::SetAccessFlagsDuringLinking(uint32_t new_access_flags) {
1039   SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1040       AccessFlagsOffset(), new_access_flags);
1041 }
1042 
SetAccessFlags(uint32_t new_access_flags)1043 inline void Class::SetAccessFlags(uint32_t new_access_flags) {
1044   // Called inside a transaction when setting pre-verified flag during boot image compilation.
1045   if (Runtime::Current()->IsActiveTransaction()) {
1046     SetField32<true>(AccessFlagsOffset(), new_access_flags);
1047   } else {
1048     SetField32<false>(AccessFlagsOffset(), new_access_flags);
1049   }
1050 }
1051 
SetClassFlags(uint32_t new_flags)1052 inline void Class::SetClassFlags(uint32_t new_flags) {
1053   SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1054       OFFSET_OF_OBJECT_MEMBER(Class, class_flags_), new_flags);
1055 }
1056 
NumDirectInterfaces()1057 inline uint32_t Class::NumDirectInterfaces() {
1058   if (IsPrimitive()) {
1059     return 0;
1060   } else if (IsArrayClass()) {
1061     return 2;
1062   } else if (IsProxyClass()) {
1063     ObjPtr<ObjectArray<Class>> interfaces = GetProxyInterfaces();
1064     return interfaces != nullptr ? interfaces->GetLength() : 0;
1065   } else {
1066     const dex::TypeList* interfaces = GetInterfaceTypeList();
1067     if (interfaces == nullptr) {
1068       return 0;
1069     } else {
1070       return interfaces->Size();
1071     }
1072   }
1073 }
1074 
GetDirectMethods(PointerSize pointer_size)1075 inline ArraySlice<ArtMethod> Class::GetDirectMethods(PointerSize pointer_size) {
1076   CheckPointerSize(pointer_size);
1077   return GetDirectMethodsSliceUnchecked(pointer_size);
1078 }
1079 
GetDeclaredMethods(PointerSize pointer_size)1080 inline ArraySlice<ArtMethod> Class::GetDeclaredMethods(PointerSize pointer_size) {
1081   return GetDeclaredMethodsSliceUnchecked(pointer_size);
1082 }
1083 
GetDeclaredVirtualMethods(PointerSize pointer_size)1084 inline ArraySlice<ArtMethod> Class::GetDeclaredVirtualMethods(PointerSize pointer_size) {
1085   return GetDeclaredVirtualMethodsSliceUnchecked(pointer_size);
1086 }
1087 
GetVirtualMethods(PointerSize pointer_size)1088 inline ArraySlice<ArtMethod> Class::GetVirtualMethods(PointerSize pointer_size) {
1089   CheckPointerSize(pointer_size);
1090   return GetVirtualMethodsSliceUnchecked(pointer_size);
1091 }
1092 
GetCopiedMethods(PointerSize pointer_size)1093 inline ArraySlice<ArtMethod> Class::GetCopiedMethods(PointerSize pointer_size) {
1094   CheckPointerSize(pointer_size);
1095   return GetCopiedMethodsSliceUnchecked(pointer_size);
1096 }
1097 
1098 
GetMethods(PointerSize pointer_size)1099 inline ArraySlice<ArtMethod> Class::GetMethods(PointerSize pointer_size) {
1100   CheckPointerSize(pointer_size);
1101   LengthPrefixedArray<ArtMethod>* methods = GetMethodsPtr();
1102   return GetMethodsSliceRangeUnchecked(methods, pointer_size, 0u, NumMethods(methods));
1103 }
1104 
GetFields()1105 inline IterationRange<StrideIterator<ArtField>> Class::GetFields() {
1106   return MakeIterationRangeFromLengthPrefixedArray(GetFieldsPtr());
1107 }
1108 
GetFieldsUnchecked()1109 inline IterationRange<StrideIterator<ArtField>> Class::GetFieldsUnchecked() {
1110   return MakeIterationRangeFromLengthPrefixedArray(GetFieldsPtrUnchecked());
1111 }
1112 
CheckPointerSize(PointerSize pointer_size)1113 inline void Class::CheckPointerSize(PointerSize pointer_size) {
1114   DCHECK_EQ(pointer_size, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
1115 }
1116 
1117 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetComponentType()1118 inline ObjPtr<Class> Class::GetComponentType() {
1119   return GetFieldObject<Class, kVerifyFlags, kReadBarrierOption>(ComponentTypeOffset());
1120 }
1121 
SetComponentType(ObjPtr<Class> new_component_type)1122 inline void Class::SetComponentType(ObjPtr<Class> new_component_type) {
1123   DCHECK(GetComponentType() == nullptr);
1124   DCHECK(new_component_type != nullptr);
1125   // Component type is invariant: use non-transactional mode without check.
1126   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1127       ComponentTypeOffset(), new_component_type);
1128 }
1129 
GetComponentSize()1130 inline size_t Class::GetComponentSize() {
1131   return 1U << GetComponentSizeShift();
1132 }
1133 
1134 template <ReadBarrierOption kReadBarrierOption>
GetComponentSizeShift()1135 inline size_t Class::GetComponentSizeShift() {
1136   return GetComponentType<kDefaultVerifyFlags, kReadBarrierOption>()->GetPrimitiveTypeSizeShift();
1137 }
1138 
IsObjectClass()1139 inline bool Class::IsObjectClass() {
1140   // No read barrier is needed for comparing with null. See ReadBarrierOption.
1141   return !IsPrimitive() && GetSuperClass<kDefaultVerifyFlags, kWithoutReadBarrier>() == nullptr;
1142 }
1143 
IsInstantiableNonArray()1144 inline bool Class::IsInstantiableNonArray() {
1145   return !IsPrimitive() && !IsInterface() && !IsAbstract() && !IsArrayClass();
1146 }
1147 
1148 template<VerifyObjectFlags kVerifyFlags>
IsInstantiable()1149 bool Class::IsInstantiable() {
1150   return (!IsPrimitive<kVerifyFlags>() &&
1151           !IsInterface<kVerifyFlags>() &&
1152           !IsAbstract<kVerifyFlags>()) ||
1153       (IsAbstract<kVerifyFlags>() && IsArrayClass<kVerifyFlags>());
1154 }
1155 
1156 template<VerifyObjectFlags kVerifyFlags>
IsArrayClass()1157 inline bool Class::IsArrayClass() {
1158   // We do not need a read barrier for comparing with null.
1159   return GetComponentType<kVerifyFlags, kWithoutReadBarrier>() != nullptr;
1160 }
1161 
1162 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
IsObjectArrayClass()1163 inline bool Class::IsObjectArrayClass() {
1164   const ObjPtr<Class> component_type = GetComponentType<kVerifyFlags, kReadBarrierOption>();
1165   constexpr VerifyObjectFlags kNewFlags = RemoveThisFlags(kVerifyFlags);
1166   return component_type != nullptr && !component_type->IsPrimitive<kNewFlags>();
1167 }
1168 
1169 template<VerifyObjectFlags kVerifyFlags>
IsPrimitiveArray()1170 bool Class::IsPrimitiveArray() {
1171   // We do not need a read barrier here as the primitive type is constant,
1172   // both from-space and to-space component type classes shall yield the same result.
1173   const ObjPtr<Class> component_type = GetComponentType<kVerifyFlags, kWithoutReadBarrier>();
1174   constexpr VerifyObjectFlags kNewFlags = RemoveThisFlags(kVerifyFlags);
1175   return component_type != nullptr && component_type->IsPrimitive<kNewFlags>();
1176 }
1177 
IsAssignableFrom(ObjPtr<Class> src)1178 inline bool Class::IsAssignableFrom(ObjPtr<Class> src) {
1179   DCHECK(src != nullptr);
1180   if (this == src) {
1181     // Can always assign to things of the same type.
1182     return true;
1183   } else if (IsObjectClass()) {
1184     // Can assign any reference to java.lang.Object.
1185     return !src->IsPrimitive();
1186   } else if (IsInterface()) {
1187     return src->Implements(this);
1188   } else if (src->IsArrayClass()) {
1189     return IsAssignableFromArray(src);
1190   } else {
1191     return !src->IsInterface() && src->IsSubClass(this);
1192   }
1193 }
1194 
NumDirectMethods()1195 inline uint32_t Class::NumDirectMethods() {
1196   return GetVirtualMethodsStartOffset();
1197 }
1198 
NumDeclaredVirtualMethods()1199 inline uint32_t Class::NumDeclaredVirtualMethods() {
1200   return GetCopiedMethodsStartOffset() - GetVirtualMethodsStartOffset();
1201 }
1202 
NumVirtualMethods()1203 inline uint32_t Class::NumVirtualMethods() {
1204   return NumMethods() - GetVirtualMethodsStartOffset();
1205 }
1206 
NumFields()1207 inline uint32_t Class::NumFields() {
1208   LengthPrefixedArray<ArtField>* arr = GetFieldsPtrUnchecked();
1209   return arr != nullptr ? arr->size() : 0u;
1210 }
1211 
HasStaticFields()1212 inline bool Class::HasStaticFields() {
1213   if (IsArrayClass() || IsPrimitive()) {
1214     return false;
1215   }
1216   ClassAccessor accessor(GetDexFile(), GetDexClassDefIndex());
1217   return accessor.NumStaticFields() != 0u;
1218 }
1219 
ComputeNumStaticFields()1220 inline uint32_t Class::ComputeNumStaticFields() {
1221   uint32_t num = 0;
1222   for (ArtField& field : GetFields()) {
1223     if (field.IsStatic()) {
1224       ++num;
1225     }
1226   }
1227   return num;
1228 }
1229 
ComputeNumInstanceFields()1230 inline uint32_t Class::ComputeNumInstanceFields() {
1231   uint32_t num = 0;
1232   for (ArtField& field : GetFields()) {
1233     if (!field.IsStatic()) {
1234       ++num;
1235     }
1236   }
1237   return num;
1238 }
1239 
1240 template <typename T, VerifyObjectFlags kVerifyFlags, typename Visitor>
FixupNativePointer(Class * dest,PointerSize pointer_size,const Visitor & visitor,MemberOffset member_offset)1241 inline void Class::FixupNativePointer(
1242     Class* dest, PointerSize pointer_size, const Visitor& visitor, MemberOffset member_offset) {
1243   void** address =
1244       reinterpret_cast<void**>(reinterpret_cast<uintptr_t>(dest) + member_offset.Uint32Value());
1245   T old_value = GetFieldPtrWithSize<T, kVerifyFlags>(member_offset, pointer_size);
1246   T new_value = visitor(old_value, address);
1247   if (old_value != new_value) {
1248     dest->SetFieldPtrWithSize</* kTransactionActive= */ false,
1249                               /* kCheckTransaction= */ true,
1250                               kVerifyNone>(member_offset, new_value, pointer_size);
1251   }
1252 }
1253 
1254 template <VerifyObjectFlags kVerifyFlags, typename Visitor>
FixupNativePointers(Class * dest,PointerSize pointer_size,const Visitor & visitor)1255 inline void Class::FixupNativePointers(Class* dest,
1256                                        PointerSize pointer_size,
1257                                        const Visitor& visitor) {
1258   // Update the field array.
1259   FixupNativePointer<LengthPrefixedArray<ArtField>*, kVerifyFlags>(
1260       dest, pointer_size, visitor, OFFSET_OF_OBJECT_MEMBER(Class, fields_));
1261   // Update method array.
1262   FixupNativePointer<LengthPrefixedArray<ArtMethod>*, kVerifyFlags>(
1263       dest, pointer_size, visitor, OFFSET_OF_OBJECT_MEMBER(Class, methods_));
1264   // Fix up embedded tables.
1265   if (!IsTemp<kVerifyNone>() && ShouldHaveEmbeddedVTable<kVerifyNone>()) {
1266     for (int32_t i = 0, count = GetEmbeddedVTableLength<kVerifyFlags>(); i < count; ++i) {
1267       FixupNativePointer<ArtMethod*, kVerifyFlags>(
1268           dest, pointer_size, visitor, EmbeddedVTableEntryOffset(i, pointer_size));
1269     }
1270   }
1271   if (!IsTemp<kVerifyNone>() && ShouldHaveImt<kVerifyNone>()) {
1272     FixupNativePointer<ImTable*, kVerifyFlags>(
1273         dest, pointer_size, visitor, ImtPtrOffset(pointer_size));
1274   }
1275 }
1276 
CanAccess(ObjPtr<Class> that)1277 inline bool Class::CanAccess(ObjPtr<Class> that) {
1278   return this == that || that->IsPublic() || this->IsInSamePackage(that);
1279 }
1280 
1281 
CanAccessMember(ObjPtr<Class> access_to,uint32_t member_flags)1282 inline bool Class::CanAccessMember(ObjPtr<Class> access_to, uint32_t member_flags) {
1283   // Classes can access all of their own members
1284   if (this == access_to) {
1285     return true;
1286   }
1287   // Public members are trivially accessible
1288   if (member_flags & kAccPublic) {
1289     return true;
1290   }
1291   // Private members are trivially not accessible
1292   if (member_flags & kAccPrivate) {
1293     return false;
1294   }
1295   // Check for protected access from a sub-class, which may or may not be in the same package.
1296   if (member_flags & kAccProtected) {
1297     // This implementation is not compliant. We should actually check whether
1298     // the caller is a subclass of the static type of the receiver, instead of the declaring
1299     // class of the method we are trying to access.
1300     //
1301     // For example, a class outside of java.lang should not ne able to access `Object.clone`,
1302     // but this implementation allows it.
1303     //
1304     // To not break existing code, we decided not to fix this and accept the
1305     // leniency.
1306     if (access_to->IsAssignableFrom(this)) {
1307       return true;
1308     }
1309   }
1310   // Allow protected access from other classes in the same package.
1311   return this->IsInSamePackage(access_to);
1312 }
1313 
CannotBeAssignedFromOtherTypes()1314 inline bool Class::CannotBeAssignedFromOtherTypes() {
1315   if (!IsArrayClass()) {
1316     return IsFinal();
1317   }
1318   ObjPtr<Class> component = GetComponentType();
1319   return component->IsPrimitive() || component->CannotBeAssignedFromOtherTypes();
1320 }
1321 
SetClassLoader(ObjPtr<ClassLoader> new_class_loader)1322 inline void Class::SetClassLoader(ObjPtr<ClassLoader> new_class_loader) {
1323   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1324       OFFSET_OF_OBJECT_MEMBER(Class, class_loader_), new_class_loader);
1325 }
1326 
SetRecursivelyInitialized()1327 inline void Class::SetRecursivelyInitialized() {
1328   DCHECK_EQ(GetLockOwnerThreadId(), Thread::Current()->GetThreadId());
1329   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1330   SetAccessFlags(flags | kAccRecursivelyInitialized);
1331 }
1332 
SetHasDefaultMethods()1333 inline void Class::SetHasDefaultMethods() {
1334   DCHECK_EQ(GetLockOwnerThreadId(), Thread::Current()->GetThreadId());
1335   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1336   SetAccessFlagsDuringLinking(flags | kAccHasDefaultMethod);
1337 }
1338 
SetHasTypeChecksFailure()1339 inline void Class::SetHasTypeChecksFailure() {
1340   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1341   SetAccessFlags(flags | kAccHasTypeChecksFailure);
1342 }
1343 
HasTypeChecksFailure()1344 inline bool Class::HasTypeChecksFailure() {
1345   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1346   return (flags & kAccHasTypeChecksFailure) != 0u;
1347 }
1348 
ClearFinalizable()1349 inline void Class::ClearFinalizable() {
1350   // We're clearing the finalizable flag only for `Object` and `Enum`
1351   // during early setup without the boot image.
1352   DCHECK(IsObjectClass() ||
1353          (IsBootStrapClassLoaded() && DescriptorEquals("Ljava/lang/Enum;")));
1354   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1355   SetAccessFlagsDuringLinking(flags & ~kAccClassIsFinalizable);
1356 }
1357 
FindSuperImt(PointerSize pointer_size)1358 inline ImTable* Class::FindSuperImt(PointerSize pointer_size) {
1359   ObjPtr<mirror::Class> klass = this;
1360   while (klass->HasSuperClass()) {
1361     klass = klass->GetSuperClass();
1362     if (klass->ShouldHaveImt()) {
1363       return klass->GetImt(pointer_size);
1364     }
1365   }
1366   return nullptr;
1367 }
1368 
FindDeclaredField(uint32_t dex_field_idx)1369 ALWAYS_INLINE FLATTEN inline ArtField* Class::FindDeclaredField(uint32_t dex_field_idx) {
1370   size_t num_fields = NumFields();
1371   if (num_fields > 0) {
1372     // The field array is an ordered list of fields where there may be missing
1373     // indices. For example, it could be [40, 42], but in 90% of cases cases we have
1374     // [40, 41, 42]. The latter is the case we are optimizing for, where for
1375     // example `dex_field_idx` is 41, and we can just substract it with the
1376     // first field index (40) and directly access the array with that index (1).
1377     uint32_t index = dex_field_idx - GetField(0)->GetDexFieldIndex();
1378     if (index < num_fields) {
1379       ArtField* field = GetField(index);
1380       if (field->GetDexFieldIndex() == dex_field_idx) {
1381         return field;
1382       }
1383     } else {
1384       index = num_fields;
1385     }
1386     // If there is a field, it's down the array. The array is ordered by field
1387     // index, so we know we can stop the search if `dex_field_idx` is greater
1388     // than the current field's index.
1389     for (; index > 0; --index) {
1390       ArtField* field = GetField(index - 1);
1391       if (field->GetDexFieldIndex() == dex_field_idx) {
1392         return field;
1393       } else if (field->GetDexFieldIndex() < dex_field_idx) {
1394         break;
1395       }
1396     }
1397   }
1398   return nullptr;
1399 }
1400 
1401 }  // namespace mirror
1402 }  // namespace art
1403 
1404 #endif  // ART_RUNTIME_MIRROR_CLASS_INL_H_
1405