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