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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 
CanAccessResolvedField(ObjPtr<Class> access_to,ArtField * field,ObjPtr<DexCache> dex_cache,uint32_t field_idx)501 inline bool Class::CanAccessResolvedField(ObjPtr<Class> access_to,
502                                           ArtField* field,
503                                           ObjPtr<DexCache> dex_cache,
504                                           uint32_t field_idx) {
505   return ResolvedFieldAccessTest<false>(access_to, field, dex_cache, field_idx);
506 }
507 
CheckResolvedFieldAccess(ObjPtr<Class> access_to,ArtField * field,ObjPtr<DexCache> dex_cache,uint32_t field_idx)508 inline bool Class::CheckResolvedFieldAccess(ObjPtr<Class> access_to,
509                                             ArtField* field,
510                                             ObjPtr<DexCache> dex_cache,
511                                             uint32_t field_idx) {
512   return ResolvedFieldAccessTest<true>(access_to, field, dex_cache, field_idx);
513 }
514 
IsObsoleteVersionOf(ObjPtr<Class> klass)515 inline bool Class::IsObsoleteVersionOf(ObjPtr<Class> klass) {
516   DCHECK(!klass->IsObsoleteObject()) << klass->PrettyClass() << " is obsolete!";
517   if (LIKELY(!IsObsoleteObject())) {
518     return false;
519   }
520   ObjPtr<Class> current(klass);
521   do {
522     if (UNLIKELY(current == this)) {
523       return true;
524     } else {
525       current = current->GetObsoleteClass();
526     }
527   } while (!current.IsNull());
528   return false;
529 }
530 
IsSubClass(ObjPtr<Class> klass)531 inline bool Class::IsSubClass(ObjPtr<Class> klass) {
532   // Since the SubtypeCheck::IsSubtypeOf needs to lookup the Depth,
533   // it is always O(Depth) in terms of speed to do the check.
534   //
535   // So always do the "slow" linear scan in normal release builds.
536   //
537   // Future note: If we could have the depth in O(1) we could use the 'fast'
538   // method instead as it avoids a loop and a read barrier.
539   bool result = false;
540   DCHECK(!IsInterface()) << PrettyClass();
541   DCHECK(!IsArrayClass()) << PrettyClass();
542   ObjPtr<Class> current = this;
543   do {
544     if (current == klass) {
545       result = true;
546       break;
547     }
548     current = current->GetSuperClass();
549   } while (current != nullptr);
550 
551   if (kIsDebugBuild && kBitstringSubtypeCheckEnabled) {
552     ObjPtr<mirror::Class> dis(this);
553 
554     SubtypeCheckInfo::Result sc_result = SubtypeCheck<ObjPtr<Class>>::IsSubtypeOf(dis, klass);
555     if (sc_result != SubtypeCheckInfo::kUnknownSubtypeOf) {
556       // Note: The "kUnknownSubTypeOf" can be avoided if and only if:
557       //   SubtypeCheck::EnsureInitialized(source)
558       //       happens-before source.IsSubClass(target)
559       //   SubtypeCheck::EnsureAssigned(target).GetState() == Assigned
560       //       happens-before source.IsSubClass(target)
561       //
562       // When code generated by optimizing compiler executes this operation, both
563       // happens-before are guaranteed, so there is no fallback code there.
564       SubtypeCheckInfo::Result expected_result =
565           result ? SubtypeCheckInfo::kSubtypeOf : SubtypeCheckInfo::kNotSubtypeOf;
566       DCHECK_EQ(expected_result, sc_result)
567           << "source: " << PrettyClass() << "target: " << klass->PrettyClass();
568     }
569   }
570 
571   return result;
572 }
573 
FindVirtualMethodForInterface(ArtMethod * method,PointerSize pointer_size)574 inline ArtMethod* Class::FindVirtualMethodForInterface(ArtMethod* method,
575                                                        PointerSize pointer_size) {
576   ObjPtr<Class> declaring_class = method->GetDeclaringClass();
577   DCHECK(declaring_class != nullptr) << PrettyClass();
578   if (UNLIKELY(!declaring_class->IsInterface())) {
579     DCHECK(declaring_class->IsObjectClass()) << method->PrettyMethod();
580     DCHECK(method->IsPublic() && !method->IsStatic());
581     return FindVirtualMethodForVirtual(method, pointer_size);
582   }
583   DCHECK(!method->IsCopied());
584   // TODO cache to improve lookup speed
585   const int32_t iftable_count = GetIfTableCount();
586   ObjPtr<IfTable> iftable = GetIfTable();
587   for (int32_t i = 0; i < iftable_count; i++) {
588     if (iftable->GetInterface(i) == declaring_class) {
589       return iftable->GetMethodArray(i)->GetElementPtrSize<ArtMethod*>(
590           method->GetMethodIndex(), pointer_size);
591     }
592   }
593   return nullptr;
594 }
595 
FindVirtualMethodForVirtual(ArtMethod * method,PointerSize pointer_size)596 inline ArtMethod* Class::FindVirtualMethodForVirtual(ArtMethod* method, PointerSize pointer_size) {
597   // Only miranda or default methods may come from interfaces and be used as a virtual.
598   DCHECK(!method->GetDeclaringClass()->IsInterface() || method->IsDefault() || method->IsMiranda());
599   // The argument method may from a super class.
600   // Use the index to a potentially overridden one for this instance's class.
601   return GetVTableEntry(method->GetMethodIndex(), pointer_size);
602 }
603 
FindVirtualMethodForSuper(ArtMethod * method,PointerSize pointer_size)604 inline ArtMethod* Class::FindVirtualMethodForSuper(ArtMethod* method, PointerSize pointer_size) {
605   DCHECK(!method->GetDeclaringClass()->IsInterface());
606   return GetSuperClass()->GetVTableEntry(method->GetMethodIndex(), pointer_size);
607 }
608 
FindVirtualMethodForVirtualOrInterface(ArtMethod * method,PointerSize pointer_size)609 inline ArtMethod* Class::FindVirtualMethodForVirtualOrInterface(ArtMethod* method,
610                                                                 PointerSize pointer_size) {
611   if (method->IsDirect()) {
612     return method;
613   }
614   if (method->GetDeclaringClass()->IsInterface() && !method->IsCopied()) {
615     return FindVirtualMethodForInterface(method, pointer_size);
616   }
617   return FindVirtualMethodForVirtual(method, pointer_size);
618 }
619 
620 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetIfTable()621 inline ObjPtr<IfTable> Class::GetIfTable() {
622   ObjPtr<IfTable> ret = GetFieldObject<IfTable, kVerifyFlags, kReadBarrierOption>(IfTableOffset());
623   DCHECK(ret != nullptr) << PrettyClass(this);
624   return ret;
625 }
626 
627 template<VerifyObjectFlags kVerifyFlags>
GetIfTableCount()628 inline int32_t Class::GetIfTableCount() {
629   // We do not need a read barrier here as the length is constant,
630   // both from-space and to-space iftables shall yield the same result.
631   return GetIfTable<kVerifyFlags, kWithoutReadBarrier>()->Count();
632 }
633 
SetIfTable(ObjPtr<IfTable> new_iftable)634 inline void Class::SetIfTable(ObjPtr<IfTable> new_iftable) {
635   DCHECK(new_iftable != nullptr) << PrettyClass(this);
636   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
637       IfTableOffset(), new_iftable);
638 }
639 
GetIFieldsPtr()640 inline LengthPrefixedArray<ArtField>* Class::GetIFieldsPtr() {
641   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
642   return GetFieldPtr<LengthPrefixedArray<ArtField>*>(OFFSET_OF_OBJECT_MEMBER(Class, ifields_));
643 }
644 
645 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetFirstReferenceInstanceFieldOffset()646 inline MemberOffset Class::GetFirstReferenceInstanceFieldOffset() {
647   ObjPtr<Class> super_class = GetSuperClass<kVerifyFlags, kReadBarrierOption>();
648   return (super_class != nullptr)
649       ? MemberOffset(RoundUp(super_class->GetObjectSize<kVerifyFlags>(), kHeapReferenceSize))
650       : ClassOffset();
651 }
652 
653 template <VerifyObjectFlags kVerifyFlags>
GetFirstReferenceStaticFieldOffset(PointerSize pointer_size)654 inline MemberOffset Class::GetFirstReferenceStaticFieldOffset(PointerSize pointer_size) {
655   DCHECK(IsResolved<kVerifyFlags>());
656   uint32_t base = sizeof(Class);  // Static fields come after the class.
657   if (ShouldHaveEmbeddedVTable<kVerifyFlags>()) {
658     // Static fields come after the embedded tables.
659     base = Class::ComputeClassSize(
660         true, GetEmbeddedVTableLength<kVerifyFlags>(), 0, 0, 0, 0, 0, pointer_size);
661   }
662   return MemberOffset(base);
663 }
664 
GetFirstReferenceStaticFieldOffsetDuringLinking(PointerSize pointer_size)665 inline MemberOffset Class::GetFirstReferenceStaticFieldOffsetDuringLinking(
666     PointerSize pointer_size) {
667   DCHECK(IsLoaded());
668   uint32_t base = sizeof(Class);  // Static fields come after the class.
669   if (ShouldHaveEmbeddedVTable()) {
670     // Static fields come after the embedded tables.
671     base = Class::ComputeClassSize(true, GetVTableDuringLinking()->GetLength(),
672                                            0, 0, 0, 0, 0, pointer_size);
673   }
674   return MemberOffset(base);
675 }
676 
SetIFieldsPtr(LengthPrefixedArray<ArtField> * new_ifields)677 inline void Class::SetIFieldsPtr(LengthPrefixedArray<ArtField>* new_ifields) {
678   DCHECK(GetIFieldsPtrUnchecked() == nullptr);
679   return SetFieldPtr<false>(OFFSET_OF_OBJECT_MEMBER(Class, ifields_), new_ifields);
680 }
681 
SetIFieldsPtrUnchecked(LengthPrefixedArray<ArtField> * new_ifields)682 inline void Class::SetIFieldsPtrUnchecked(LengthPrefixedArray<ArtField>* new_ifields) {
683   SetFieldPtr<false, true, kVerifyNone>(OFFSET_OF_OBJECT_MEMBER(Class, ifields_), new_ifields);
684 }
685 
GetSFieldsPtrUnchecked()686 inline LengthPrefixedArray<ArtField>* Class::GetSFieldsPtrUnchecked() {
687   return GetFieldPtr<LengthPrefixedArray<ArtField>*>(OFFSET_OF_OBJECT_MEMBER(Class, sfields_));
688 }
689 
GetIFieldsPtrUnchecked()690 inline LengthPrefixedArray<ArtField>* Class::GetIFieldsPtrUnchecked() {
691   return GetFieldPtr<LengthPrefixedArray<ArtField>*>(OFFSET_OF_OBJECT_MEMBER(Class, ifields_));
692 }
693 
GetSFieldsPtr()694 inline LengthPrefixedArray<ArtField>* Class::GetSFieldsPtr() {
695   DCHECK(IsLoaded() || IsErroneous()) << GetStatus();
696   return GetSFieldsPtrUnchecked();
697 }
698 
SetSFieldsPtr(LengthPrefixedArray<ArtField> * new_sfields)699 inline void Class::SetSFieldsPtr(LengthPrefixedArray<ArtField>* new_sfields) {
700   DCHECK((IsRetired() && new_sfields == nullptr) ||
701          GetFieldPtr<ArtField*>(OFFSET_OF_OBJECT_MEMBER(Class, sfields_)) == nullptr);
702   SetFieldPtr<false>(OFFSET_OF_OBJECT_MEMBER(Class, sfields_), new_sfields);
703 }
704 
SetSFieldsPtrUnchecked(LengthPrefixedArray<ArtField> * new_sfields)705 inline void Class::SetSFieldsPtrUnchecked(LengthPrefixedArray<ArtField>* new_sfields) {
706   SetFieldPtr<false, true, kVerifyNone>(OFFSET_OF_OBJECT_MEMBER(Class, sfields_), new_sfields);
707 }
708 
GetStaticField(uint32_t i)709 inline ArtField* Class::GetStaticField(uint32_t i) {
710   return &GetSFieldsPtr()->At(i);
711 }
712 
GetInstanceField(uint32_t i)713 inline ArtField* Class::GetInstanceField(uint32_t i) {
714   return &GetIFieldsPtr()->At(i);
715 }
716 
717 template<VerifyObjectFlags kVerifyFlags>
GetReferenceInstanceOffsets()718 inline uint32_t Class::GetReferenceInstanceOffsets() {
719   DCHECK(IsResolved<kVerifyFlags>() || IsErroneous<kVerifyFlags>());
720   return GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, reference_instance_offsets_));
721 }
722 
SetClinitThreadId(pid_t new_clinit_thread_id)723 inline void Class::SetClinitThreadId(pid_t new_clinit_thread_id) {
724   SetField32Transaction(OFFSET_OF_OBJECT_MEMBER(Class, clinit_thread_id_), new_clinit_thread_id);
725 }
726 
727 template<VerifyObjectFlags kVerifyFlags,
728          ReadBarrierOption kReadBarrierOption>
GetName()729 inline ObjPtr<String> Class::GetName() {
730   return GetFieldObject<String, kVerifyFlags, kReadBarrierOption>(
731       OFFSET_OF_OBJECT_MEMBER(Class, name_));
732 }
733 
SetName(ObjPtr<String> name)734 inline void Class::SetName(ObjPtr<String> name) {
735   SetFieldObjectTransaction(OFFSET_OF_OBJECT_MEMBER(Class, name_), name);
736 }
737 
738 template<VerifyObjectFlags kVerifyFlags>
GetPrimitiveType()739 inline Primitive::Type Class::GetPrimitiveType() {
740   static_assert(sizeof(Primitive::Type) == sizeof(int32_t),
741                 "art::Primitive::Type and int32_t have different sizes.");
742   int32_t v32 = GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, primitive_type_));
743   Primitive::Type type = static_cast<Primitive::Type>(v32 & kPrimitiveTypeMask);
744   DCHECK_EQ(static_cast<size_t>(v32 >> kPrimitiveTypeSizeShiftShift),
745             Primitive::ComponentSizeShift(type));
746   return type;
747 }
748 
749 template<VerifyObjectFlags kVerifyFlags>
GetPrimitiveTypeSizeShift()750 inline size_t Class::GetPrimitiveTypeSizeShift() {
751   static_assert(sizeof(Primitive::Type) == sizeof(int32_t),
752                 "art::Primitive::Type and int32_t have different sizes.");
753   int32_t v32 = GetField32<kVerifyFlags>(OFFSET_OF_OBJECT_MEMBER(Class, primitive_type_));
754   size_t size_shift = static_cast<Primitive::Type>(v32 >> kPrimitiveTypeSizeShiftShift);
755   DCHECK_EQ(size_shift,
756             Primitive::ComponentSizeShift(static_cast<Primitive::Type>(v32 & kPrimitiveTypeMask)));
757   return size_shift;
758 }
759 
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)760 inline uint32_t Class::ComputeClassSize(bool has_embedded_vtable,
761                                         uint32_t num_vtable_entries,
762                                         uint32_t num_8bit_static_fields,
763                                         uint32_t num_16bit_static_fields,
764                                         uint32_t num_32bit_static_fields,
765                                         uint32_t num_64bit_static_fields,
766                                         uint32_t num_ref_static_fields,
767                                         PointerSize pointer_size) {
768   // Space used by java.lang.Class and its instance fields.
769   uint32_t size = sizeof(Class);
770   // Space used by embedded tables.
771   if (has_embedded_vtable) {
772     size = RoundUp(size + sizeof(uint32_t), static_cast<size_t>(pointer_size));
773     size += static_cast<size_t>(pointer_size);  // size of pointer to IMT
774     size += num_vtable_entries * VTableEntrySize(pointer_size);
775   }
776 
777   // Space used by reference statics.
778   size += num_ref_static_fields * kHeapReferenceSize;
779   if (!IsAligned<8>(size) && num_64bit_static_fields > 0) {
780     uint32_t gap = 8 - (size & 0x7);
781     size += gap;  // will be padded
782     // Shuffle 4-byte fields forward.
783     while (gap >= sizeof(uint32_t) && num_32bit_static_fields != 0) {
784       --num_32bit_static_fields;
785       gap -= sizeof(uint32_t);
786     }
787     // Shuffle 2-byte fields forward.
788     while (gap >= sizeof(uint16_t) && num_16bit_static_fields != 0) {
789       --num_16bit_static_fields;
790       gap -= sizeof(uint16_t);
791     }
792     // Shuffle byte fields forward.
793     while (gap >= sizeof(uint8_t) && num_8bit_static_fields != 0) {
794       --num_8bit_static_fields;
795       gap -= sizeof(uint8_t);
796     }
797   }
798   // Guaranteed to be at least 4 byte aligned. No need for further alignments.
799   // Space used for primitive static fields.
800   size += num_8bit_static_fields * sizeof(uint8_t) + num_16bit_static_fields * sizeof(uint16_t) +
801       num_32bit_static_fields * sizeof(uint32_t) + num_64bit_static_fields * sizeof(uint64_t);
802   return size;
803 }
804 
805 template<VerifyObjectFlags kVerifyFlags>
IsClassClass()806 inline bool Class::IsClassClass() {
807   // OK to look at from-space copies since java.lang.Class.class is non-moveable
808   // (even when running without boot image, see ClassLinker::InitWithoutImage())
809   // and we're reading it for comparison only. See ReadBarrierOption.
810   ObjPtr<Class> java_lang_Class = GetClass<kVerifyFlags, kWithoutReadBarrier>();
811   return this == java_lang_Class;
812 }
813 
GetDexFile()814 inline const DexFile& Class::GetDexFile() {
815   // From-space version is the same as the to-space version since the dex file never changes.
816   // Avoiding the read barrier here is important to prevent recursive AssertToSpaceInvariant issues
817   // from PrettyTypeOf.
818   return *GetDexCache<kDefaultVerifyFlags, kWithoutReadBarrier>()->GetDexFile();
819 }
820 
DescriptorEquals(const char * match)821 inline bool Class::DescriptorEquals(const char* match) {
822   ObjPtr<mirror::Class> klass = this;
823   while (klass->IsArrayClass()) {
824     if (match[0] != '[') {
825       return false;
826     }
827     ++match;
828     // No read barrier needed, we're reading a chain of constant references for comparison
829     // with null. Then we follow up below with reading constant references to read constant
830     // primitive data in both proxy and non-proxy paths. See ReadBarrierOption.
831     klass = klass->GetComponentType<kDefaultVerifyFlags, kWithoutReadBarrier>();
832   }
833   if (klass->IsPrimitive()) {
834     return strcmp(Primitive::Descriptor(klass->GetPrimitiveType()), match) == 0;
835   } else if (klass->IsProxyClass()) {
836     return klass->ProxyDescriptorEquals(match);
837   } else {
838     const DexFile& dex_file = klass->GetDexFile();
839     const dex::TypeId& type_id = dex_file.GetTypeId(klass->GetDexTypeIndex());
840     return strcmp(dex_file.GetTypeDescriptor(type_id), match) == 0;
841   }
842 }
843 
DescriptorHash()844 inline uint32_t Class::DescriptorHash() {
845   // No read barriers needed, we're reading a chain of constant references for comparison with null
846   // and retrieval of constant primitive data. See `ReadBarrierOption` and `Class::GetDescriptor()`.
847   ObjPtr<mirror::Class> klass = this;
848   uint32_t hash = StartModifiedUtf8Hash();
849   while (klass->IsArrayClass()) {
850     klass = klass->GetComponentType<kDefaultVerifyFlags, kWithoutReadBarrier>();
851     hash = UpdateModifiedUtf8Hash(hash, '[');
852   }
853   if (UNLIKELY(klass->IsProxyClass())) {
854     hash = UpdateHashForProxyClass(hash, klass);
855   } else if (klass->IsPrimitive()) {
856     hash = UpdateModifiedUtf8Hash(hash, Primitive::Descriptor(klass->GetPrimitiveType())[0]);
857   } else {
858     const DexFile& dex_file = klass->GetDexFile();
859     const dex::TypeId& type_id = dex_file.GetTypeId(klass->GetDexTypeIndex());
860     std::string_view descriptor = dex_file.GetTypeDescriptorView(type_id);
861     hash = UpdateModifiedUtf8Hash(hash, descriptor);
862   }
863 
864   if (kIsDebugBuild) {
865     std::string temp;
866     CHECK_EQ(hash, ComputeModifiedUtf8Hash(GetDescriptor(&temp)));
867   }
868 
869   return hash;
870 }
871 
AssertInitializedOrInitializingInThread(Thread * self)872 inline void Class::AssertInitializedOrInitializingInThread(Thread* self) {
873   if (kIsDebugBuild && !IsInitialized()) {
874     CHECK(IsInitializing()) << PrettyClass() << " is not initializing: " << GetStatus();
875     CHECK_EQ(GetClinitThreadId(), self->GetTid())
876         << PrettyClass() << " is initializing in a different thread";
877   }
878 }
879 
GetProxyInterfaces()880 inline ObjPtr<ObjectArray<Class>> Class::GetProxyInterfaces() {
881   CHECK(IsProxyClass());
882   // First static field.
883   ArtField* field = GetStaticField(0);
884   DCHECK_STREQ(field->GetName(), "interfaces");
885   MemberOffset field_offset = field->GetOffset();
886   return GetFieldObject<ObjectArray<Class>>(field_offset);
887 }
888 
GetProxyThrows()889 inline ObjPtr<ObjectArray<ObjectArray<Class>>> Class::GetProxyThrows() {
890   CHECK(IsProxyClass());
891   // Second static field.
892   ArtField* field = GetStaticField(1);
893   DCHECK_STREQ(field->GetName(), "throws");
894   MemberOffset field_offset = field->GetOffset();
895   return GetFieldObject<ObjectArray<ObjectArray<Class>>>(field_offset);
896 }
897 
IsBootStrapClassLoaded()898 inline bool Class::IsBootStrapClassLoaded() {
899   // No read barrier is needed for comparing with null. See ReadBarrierOption.
900   return GetClassLoader<kDefaultVerifyFlags, kWithoutReadBarrier>() == nullptr;
901 }
902 
operator()903 inline void Class::InitializeClassVisitor::operator()(ObjPtr<Object> obj,
904                                                       size_t usable_size) const {
905   DCHECK_LE(class_size_, usable_size);
906   // Avoid AsClass as object is not yet in live bitmap or allocation stack.
907   ObjPtr<Class> klass = ObjPtr<Class>::DownCast(obj);
908   klass->SetClassSize(class_size_);
909   klass->SetPrimitiveType(Primitive::kPrimNot);  // Default to not being primitive.
910   klass->SetDexClassDefIndex(DexFile::kDexNoIndex16);  // Default to no valid class def index.
911   klass->SetDexTypeIndex(dex::TypeIndex(DexFile::kDexNoIndex16));  // Default to no valid type
912                                                                    // index.
913   // Default to force slow path until visibly initialized.
914   // There is no need for release store (volatile) in pre-fence visitor.
915   klass->SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
916       ObjectSizeAllocFastPathOffset(), std::numeric_limits<uint32_t>::max());
917 }
918 
SetAccessFlagsDuringLinking(uint32_t new_access_flags)919 inline void Class::SetAccessFlagsDuringLinking(uint32_t new_access_flags) {
920   SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
921       AccessFlagsOffset(), new_access_flags);
922 }
923 
SetAccessFlags(uint32_t new_access_flags)924 inline void Class::SetAccessFlags(uint32_t new_access_flags) {
925   // Called inside a transaction when setting pre-verified flag during boot image compilation.
926   if (Runtime::Current()->IsActiveTransaction()) {
927     SetField32<true>(AccessFlagsOffset(), new_access_flags);
928   } else {
929     SetField32<false>(AccessFlagsOffset(), new_access_flags);
930   }
931 }
932 
SetClassFlags(uint32_t new_flags)933 inline void Class::SetClassFlags(uint32_t new_flags) {
934   SetField32</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
935       OFFSET_OF_OBJECT_MEMBER(Class, class_flags_), new_flags);
936 }
937 
NumDirectInterfaces()938 inline uint32_t Class::NumDirectInterfaces() {
939   if (IsPrimitive()) {
940     return 0;
941   } else if (IsArrayClass()) {
942     return 2;
943   } else if (IsProxyClass()) {
944     ObjPtr<ObjectArray<Class>> interfaces = GetProxyInterfaces();
945     return interfaces != nullptr ? interfaces->GetLength() : 0;
946   } else {
947     const dex::TypeList* interfaces = GetInterfaceTypeList();
948     if (interfaces == nullptr) {
949       return 0;
950     } else {
951       return interfaces->Size();
952     }
953   }
954 }
955 
GetDirectMethods(PointerSize pointer_size)956 inline ArraySlice<ArtMethod> Class::GetDirectMethods(PointerSize pointer_size) {
957   CheckPointerSize(pointer_size);
958   return GetDirectMethodsSliceUnchecked(pointer_size);
959 }
960 
GetDeclaredMethods(PointerSize pointer_size)961 inline ArraySlice<ArtMethod> Class::GetDeclaredMethods(PointerSize pointer_size) {
962   return GetDeclaredMethodsSliceUnchecked(pointer_size);
963 }
964 
GetDeclaredVirtualMethods(PointerSize pointer_size)965 inline ArraySlice<ArtMethod> Class::GetDeclaredVirtualMethods(PointerSize pointer_size) {
966   return GetDeclaredVirtualMethodsSliceUnchecked(pointer_size);
967 }
968 
GetVirtualMethods(PointerSize pointer_size)969 inline ArraySlice<ArtMethod> Class::GetVirtualMethods(PointerSize pointer_size) {
970   CheckPointerSize(pointer_size);
971   return GetVirtualMethodsSliceUnchecked(pointer_size);
972 }
973 
GetCopiedMethods(PointerSize pointer_size)974 inline ArraySlice<ArtMethod> Class::GetCopiedMethods(PointerSize pointer_size) {
975   CheckPointerSize(pointer_size);
976   return GetCopiedMethodsSliceUnchecked(pointer_size);
977 }
978 
979 
GetMethods(PointerSize pointer_size)980 inline ArraySlice<ArtMethod> Class::GetMethods(PointerSize pointer_size) {
981   CheckPointerSize(pointer_size);
982   LengthPrefixedArray<ArtMethod>* methods = GetMethodsPtr();
983   return GetMethodsSliceRangeUnchecked(methods, pointer_size, 0u, NumMethods(methods));
984 }
985 
GetIFields()986 inline IterationRange<StrideIterator<ArtField>> Class::GetIFields() {
987   return MakeIterationRangeFromLengthPrefixedArray(GetIFieldsPtr());
988 }
989 
GetSFields()990 inline IterationRange<StrideIterator<ArtField>> Class::GetSFields() {
991   return MakeIterationRangeFromLengthPrefixedArray(GetSFieldsPtr());
992 }
993 
GetIFieldsUnchecked()994 inline IterationRange<StrideIterator<ArtField>> Class::GetIFieldsUnchecked() {
995   return MakeIterationRangeFromLengthPrefixedArray(GetIFieldsPtrUnchecked());
996 }
997 
GetSFieldsUnchecked()998 inline IterationRange<StrideIterator<ArtField>> Class::GetSFieldsUnchecked() {
999   return MakeIterationRangeFromLengthPrefixedArray(GetSFieldsPtrUnchecked());
1000 }
1001 
CheckPointerSize(PointerSize pointer_size)1002 inline void Class::CheckPointerSize(PointerSize pointer_size) {
1003   DCHECK_EQ(pointer_size, Runtime::Current()->GetClassLinker()->GetImagePointerSize());
1004 }
1005 
1006 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
GetComponentType()1007 inline ObjPtr<Class> Class::GetComponentType() {
1008   return GetFieldObject<Class, kVerifyFlags, kReadBarrierOption>(ComponentTypeOffset());
1009 }
1010 
SetComponentType(ObjPtr<Class> new_component_type)1011 inline void Class::SetComponentType(ObjPtr<Class> new_component_type) {
1012   DCHECK(GetComponentType() == nullptr);
1013   DCHECK(new_component_type != nullptr);
1014   // Component type is invariant: use non-transactional mode without check.
1015   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1016       ComponentTypeOffset(), new_component_type);
1017 }
1018 
GetComponentSize()1019 inline size_t Class::GetComponentSize() {
1020   return 1U << GetComponentSizeShift();
1021 }
1022 
1023 template <ReadBarrierOption kReadBarrierOption>
GetComponentSizeShift()1024 inline size_t Class::GetComponentSizeShift() {
1025   return GetComponentType<kDefaultVerifyFlags, kReadBarrierOption>()->GetPrimitiveTypeSizeShift();
1026 }
1027 
IsObjectClass()1028 inline bool Class::IsObjectClass() {
1029   // No read barrier is needed for comparing with null. See ReadBarrierOption.
1030   return !IsPrimitive() && GetSuperClass<kDefaultVerifyFlags, kWithoutReadBarrier>() == nullptr;
1031 }
1032 
IsInstantiableNonArray()1033 inline bool Class::IsInstantiableNonArray() {
1034   return !IsPrimitive() && !IsInterface() && !IsAbstract() && !IsArrayClass();
1035 }
1036 
1037 template<VerifyObjectFlags kVerifyFlags>
IsInstantiable()1038 bool Class::IsInstantiable() {
1039   return (!IsPrimitive<kVerifyFlags>() &&
1040           !IsInterface<kVerifyFlags>() &&
1041           !IsAbstract<kVerifyFlags>()) ||
1042       (IsAbstract<kVerifyFlags>() && IsArrayClass<kVerifyFlags>());
1043 }
1044 
1045 template<VerifyObjectFlags kVerifyFlags>
IsArrayClass()1046 inline bool Class::IsArrayClass() {
1047   // We do not need a read barrier for comparing with null.
1048   return GetComponentType<kVerifyFlags, kWithoutReadBarrier>() != nullptr;
1049 }
1050 
1051 template<VerifyObjectFlags kVerifyFlags, ReadBarrierOption kReadBarrierOption>
IsObjectArrayClass()1052 inline bool Class::IsObjectArrayClass() {
1053   const ObjPtr<Class> component_type = GetComponentType<kVerifyFlags, kReadBarrierOption>();
1054   constexpr VerifyObjectFlags kNewFlags = RemoveThisFlags(kVerifyFlags);
1055   return component_type != nullptr && !component_type->IsPrimitive<kNewFlags>();
1056 }
1057 
1058 template<VerifyObjectFlags kVerifyFlags>
IsPrimitiveArray()1059 bool Class::IsPrimitiveArray() {
1060   // We do not need a read barrier here as the primitive type is constant,
1061   // both from-space and to-space component type classes shall yield the same result.
1062   const ObjPtr<Class> component_type = GetComponentType<kVerifyFlags, kWithoutReadBarrier>();
1063   constexpr VerifyObjectFlags kNewFlags = RemoveThisFlags(kVerifyFlags);
1064   return component_type != nullptr && component_type->IsPrimitive<kNewFlags>();
1065 }
1066 
IsAssignableFrom(ObjPtr<Class> src)1067 inline bool Class::IsAssignableFrom(ObjPtr<Class> src) {
1068   DCHECK(src != nullptr);
1069   if (this == src) {
1070     // Can always assign to things of the same type.
1071     return true;
1072   } else if (IsObjectClass()) {
1073     // Can assign any reference to java.lang.Object.
1074     return !src->IsPrimitive();
1075   } else if (IsInterface()) {
1076     return src->Implements(this);
1077   } else if (src->IsArrayClass()) {
1078     return IsAssignableFromArray(src);
1079   } else {
1080     return !src->IsInterface() && src->IsSubClass(this);
1081   }
1082 }
1083 
NumDirectMethods()1084 inline uint32_t Class::NumDirectMethods() {
1085   return GetVirtualMethodsStartOffset();
1086 }
1087 
NumDeclaredVirtualMethods()1088 inline uint32_t Class::NumDeclaredVirtualMethods() {
1089   return GetCopiedMethodsStartOffset() - GetVirtualMethodsStartOffset();
1090 }
1091 
NumVirtualMethods()1092 inline uint32_t Class::NumVirtualMethods() {
1093   return NumMethods() - GetVirtualMethodsStartOffset();
1094 }
1095 
NumInstanceFields()1096 inline uint32_t Class::NumInstanceFields() {
1097   LengthPrefixedArray<ArtField>* arr = GetIFieldsPtrUnchecked();
1098   return arr != nullptr ? arr->size() : 0u;
1099 }
1100 
NumStaticFields()1101 inline uint32_t Class::NumStaticFields() {
1102   LengthPrefixedArray<ArtField>* arr = GetSFieldsPtrUnchecked();
1103   return arr != nullptr ? arr->size() : 0u;
1104 }
1105 
1106 template <typename T, VerifyObjectFlags kVerifyFlags, typename Visitor>
FixupNativePointer(Class * dest,PointerSize pointer_size,const Visitor & visitor,MemberOffset member_offset)1107 inline void Class::FixupNativePointer(
1108     Class* dest, PointerSize pointer_size, const Visitor& visitor, MemberOffset member_offset) {
1109   void** address =
1110       reinterpret_cast<void**>(reinterpret_cast<uintptr_t>(dest) + member_offset.Uint32Value());
1111   T old_value = GetFieldPtrWithSize<T, kVerifyFlags>(member_offset, pointer_size);
1112   T new_value = visitor(old_value, address);
1113   if (old_value != new_value) {
1114     dest->SetFieldPtrWithSize</* kTransactionActive= */ false,
1115                               /* kCheckTransaction= */ true,
1116                               kVerifyNone>(member_offset, new_value, pointer_size);
1117   }
1118 }
1119 
1120 template <VerifyObjectFlags kVerifyFlags, typename Visitor>
FixupNativePointers(Class * dest,PointerSize pointer_size,const Visitor & visitor)1121 inline void Class::FixupNativePointers(Class* dest,
1122                                        PointerSize pointer_size,
1123                                        const Visitor& visitor) {
1124   // Update the field arrays.
1125   FixupNativePointer<LengthPrefixedArray<ArtField>*, kVerifyFlags>(
1126       dest, pointer_size, visitor, OFFSET_OF_OBJECT_MEMBER(Class, sfields_));
1127   FixupNativePointer<LengthPrefixedArray<ArtField>*, kVerifyFlags>(
1128       dest, pointer_size, visitor, OFFSET_OF_OBJECT_MEMBER(Class, ifields_));
1129   // Update method array.
1130   FixupNativePointer<LengthPrefixedArray<ArtMethod>*, kVerifyFlags>(
1131       dest, pointer_size, visitor, OFFSET_OF_OBJECT_MEMBER(Class, methods_));
1132   // Fix up embedded tables.
1133   if (!IsTemp<kVerifyNone>() && ShouldHaveEmbeddedVTable<kVerifyNone>()) {
1134     for (int32_t i = 0, count = GetEmbeddedVTableLength<kVerifyFlags>(); i < count; ++i) {
1135       FixupNativePointer<ArtMethod*, kVerifyFlags>(
1136           dest, pointer_size, visitor, EmbeddedVTableEntryOffset(i, pointer_size));
1137     }
1138   }
1139   if (!IsTemp<kVerifyNone>() && ShouldHaveImt<kVerifyNone>()) {
1140     FixupNativePointer<ImTable*, kVerifyFlags>(
1141         dest, pointer_size, visitor, ImtPtrOffset(pointer_size));
1142   }
1143 }
1144 
CanAccess(ObjPtr<Class> that)1145 inline bool Class::CanAccess(ObjPtr<Class> that) {
1146   return that->IsPublic() || this->IsInSamePackage(that);
1147 }
1148 
1149 
CanAccessMember(ObjPtr<Class> access_to,uint32_t member_flags)1150 inline bool Class::CanAccessMember(ObjPtr<Class> access_to, uint32_t member_flags) {
1151   // Classes can access all of their own members
1152   if (this == access_to) {
1153     return true;
1154   }
1155   // Public members are trivially accessible
1156   if (member_flags & kAccPublic) {
1157     return true;
1158   }
1159   // Private members are trivially not accessible
1160   if (member_flags & kAccPrivate) {
1161     return false;
1162   }
1163   // Check for protected access from a sub-class, which may or may not be in the same package.
1164   if (member_flags & kAccProtected) {
1165     if (!this->IsInterface() && this->IsSubClass(access_to)) {
1166       return true;
1167     }
1168   }
1169   // Allow protected access from other classes in the same package.
1170   return this->IsInSamePackage(access_to);
1171 }
1172 
CannotBeAssignedFromOtherTypes()1173 inline bool Class::CannotBeAssignedFromOtherTypes() {
1174   if (!IsArrayClass()) {
1175     return IsFinal();
1176   }
1177   ObjPtr<Class> component = GetComponentType();
1178   return component->IsPrimitive() || component->CannotBeAssignedFromOtherTypes();
1179 }
1180 
SetClassLoader(ObjPtr<ClassLoader> new_class_loader)1181 inline void Class::SetClassLoader(ObjPtr<ClassLoader> new_class_loader) {
1182   SetFieldObject</*kTransactionActive=*/ false, /*kCheckTransaction=*/ false>(
1183       OFFSET_OF_OBJECT_MEMBER(Class, class_loader_), new_class_loader);
1184 }
1185 
SetRecursivelyInitialized()1186 inline void Class::SetRecursivelyInitialized() {
1187   DCHECK_EQ(GetLockOwnerThreadId(), Thread::Current()->GetThreadId());
1188   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1189   SetAccessFlags(flags | kAccRecursivelyInitialized);
1190 }
1191 
SetHasDefaultMethods()1192 inline void Class::SetHasDefaultMethods() {
1193   DCHECK_EQ(GetLockOwnerThreadId(), Thread::Current()->GetThreadId());
1194   uint32_t flags = GetField32(OFFSET_OF_OBJECT_MEMBER(Class, access_flags_));
1195   SetAccessFlagsDuringLinking(flags | kAccHasDefaultMethod);
1196 }
1197 
FindSuperImt(PointerSize pointer_size)1198 inline ImTable* Class::FindSuperImt(PointerSize pointer_size) {
1199   ObjPtr<mirror::Class> klass = this;
1200   while (klass->HasSuperClass()) {
1201     klass = klass->GetSuperClass();
1202     if (klass->ShouldHaveImt()) {
1203       return klass->GetImt(pointer_size);
1204     }
1205   }
1206   return nullptr;
1207 }
1208 
1209 }  // namespace mirror
1210 }  // namespace art
1211 
1212 #endif  // ART_RUNTIME_MIRROR_CLASS_INL_H_
1213