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      1 /*
      2  * Copyright (C) 2012 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_ENTRYPOINTS_ENTRYPOINT_UTILS_INL_H_
     18 #define ART_RUNTIME_ENTRYPOINTS_ENTRYPOINT_UTILS_INL_H_
     19 
     20 #include "entrypoint_utils.h"
     21 
     22 #include "art_method.h"
     23 #include "class_linker-inl.h"
     24 #include "common_throws.h"
     25 #include "dex_file.h"
     26 #include "entrypoints/quick/callee_save_frame.h"
     27 #include "handle_scope-inl.h"
     28 #include "indirect_reference_table.h"
     29 #include "invoke_type.h"
     30 #include "jni_internal.h"
     31 #include "mirror/array.h"
     32 #include "mirror/class-inl.h"
     33 #include "mirror/object-inl.h"
     34 #include "mirror/throwable.h"
     35 #include "nth_caller_visitor.h"
     36 #include "runtime.h"
     37 #include "stack_map.h"
     38 #include "thread.h"
     39 
     40 namespace art {
     41 
     42 template <bool kResolve = true>
     43 inline ArtMethod* GetResolvedMethod(ArtMethod* outer_method,
     44                                     const InlineInfo& inline_info,
     45                                     const InlineInfoEncoding& encoding,
     46                                     uint8_t inlining_depth)
     47   SHARED_REQUIRES(Locks::mutator_lock_) {
     48   uint32_t method_index = inline_info.GetMethodIndexAtDepth(encoding, inlining_depth);
     49   InvokeType invoke_type = static_cast<InvokeType>(
     50         inline_info.GetInvokeTypeAtDepth(encoding, inlining_depth));
     51   ArtMethod* caller = outer_method->GetDexCacheResolvedMethod(method_index, sizeof(void*));
     52   if (!caller->IsRuntimeMethod()) {
     53     return caller;
     54   }
     55   if (!kResolve) {
     56     return nullptr;
     57   }
     58 
     59   // The method in the dex cache can be the runtime method responsible for invoking
     60   // the stub that will then update the dex cache. Therefore, we need to do the
     61   // resolution ourselves.
     62 
     63   // We first find the class loader of our caller. If it is the outer method, we can directly
     64   // use its class loader. Otherwise, we also need to resolve our caller.
     65   StackHandleScope<2> hs(Thread::Current());
     66   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
     67   MutableHandle<mirror::ClassLoader> class_loader(hs.NewHandle<mirror::Class>(nullptr));
     68   Handle<mirror::DexCache> dex_cache(hs.NewHandle(outer_method->GetDexCache()));
     69   if (inlining_depth == 0) {
     70     class_loader.Assign(outer_method->GetClassLoader());
     71   } else {
     72     caller = GetResolvedMethod<kResolve>(outer_method,
     73                                          inline_info,
     74                                          encoding,
     75                                          inlining_depth - 1);
     76     class_loader.Assign(caller->GetClassLoader());
     77   }
     78 
     79   return class_linker->ResolveMethod<ClassLinker::kNoICCECheckForCache>(
     80       *outer_method->GetDexFile(), method_index, dex_cache, class_loader, nullptr, invoke_type);
     81 }
     82 
     83 inline ArtMethod* GetCalleeSaveMethodCaller(Thread* self, Runtime::CalleeSaveType type)
     84     SHARED_REQUIRES(Locks::mutator_lock_) {
     85   return GetCalleeSaveMethodCaller(
     86       self->GetManagedStack()->GetTopQuickFrame(), type, true /* do_caller_check */);
     87 }
     88 
     89 template <const bool kAccessCheck>
     90 ALWAYS_INLINE
     91 inline mirror::Class* CheckObjectAlloc(uint32_t type_idx,
     92                                        ArtMethod* method,
     93                                        Thread* self, bool* slow_path) {
     94   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
     95   size_t pointer_size = class_linker->GetImagePointerSize();
     96   mirror::Class* klass = method->GetDexCacheResolvedType<false>(type_idx, pointer_size);
     97   if (UNLIKELY(klass == nullptr)) {
     98     klass = class_linker->ResolveType(type_idx, method);
     99     *slow_path = true;
    100     if (klass == nullptr) {
    101       DCHECK(self->IsExceptionPending());
    102       return nullptr;  // Failure
    103     } else {
    104       DCHECK(!self->IsExceptionPending());
    105     }
    106   }
    107   if (kAccessCheck) {
    108     if (UNLIKELY(!klass->IsInstantiable())) {
    109       self->ThrowNewException("Ljava/lang/InstantiationError;", PrettyDescriptor(klass).c_str());
    110       *slow_path = true;
    111       return nullptr;  // Failure
    112     }
    113     mirror::Class* referrer = method->GetDeclaringClass();
    114     if (UNLIKELY(!referrer->CanAccess(klass))) {
    115       ThrowIllegalAccessErrorClass(referrer, klass);
    116       *slow_path = true;
    117       return nullptr;  // Failure
    118     }
    119   }
    120   if (UNLIKELY(!klass->IsInitialized())) {
    121     StackHandleScope<1> hs(self);
    122     Handle<mirror::Class> h_klass(hs.NewHandle(klass));
    123     // EnsureInitialized (the class initializer) might cause a GC.
    124     // may cause us to suspend meaning that another thread may try to
    125     // change the allocator while we are stuck in the entrypoints of
    126     // an old allocator. Also, the class initialization may fail. To
    127     // handle these cases we mark the slow path boolean as true so
    128     // that the caller knows to check the allocator type to see if it
    129     // has changed and to null-check the return value in case the
    130     // initialization fails.
    131     *slow_path = true;
    132     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(self, h_klass, true, true)) {
    133       DCHECK(self->IsExceptionPending());
    134       return nullptr;  // Failure
    135     } else {
    136       DCHECK(!self->IsExceptionPending());
    137     }
    138     return h_klass.Get();
    139   }
    140   return klass;
    141 }
    142 
    143 ALWAYS_INLINE
    144 inline mirror::Class* CheckClassInitializedForObjectAlloc(mirror::Class* klass,
    145                                                           Thread* self,
    146                                                           bool* slow_path) {
    147   if (UNLIKELY(!klass->IsInitialized())) {
    148     StackHandleScope<1> hs(self);
    149     Handle<mirror::Class> h_class(hs.NewHandle(klass));
    150     // EnsureInitialized (the class initializer) might cause a GC.
    151     // may cause us to suspend meaning that another thread may try to
    152     // change the allocator while we are stuck in the entrypoints of
    153     // an old allocator. Also, the class initialization may fail. To
    154     // handle these cases we mark the slow path boolean as true so
    155     // that the caller knows to check the allocator type to see if it
    156     // has changed and to null-check the return value in case the
    157     // initialization fails.
    158     *slow_path = true;
    159     if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(self, h_class, true, true)) {
    160       DCHECK(self->IsExceptionPending());
    161       return nullptr;  // Failure
    162     }
    163     return h_class.Get();
    164   }
    165   return klass;
    166 }
    167 
    168 // Given the context of a calling Method, use its DexCache to resolve a type to a Class. If it
    169 // cannot be resolved, throw an error. If it can, use it to create an instance.
    170 // When verification/compiler hasn't been able to verify access, optionally perform an access
    171 // check.
    172 template <bool kAccessCheck, bool kInstrumented>
    173 ALWAYS_INLINE
    174 inline mirror::Object* AllocObjectFromCode(uint32_t type_idx,
    175                                            ArtMethod* method,
    176                                            Thread* self,
    177                                            gc::AllocatorType allocator_type) {
    178   bool slow_path = false;
    179   mirror::Class* klass = CheckObjectAlloc<kAccessCheck>(type_idx, method, self, &slow_path);
    180   if (UNLIKELY(slow_path)) {
    181     if (klass == nullptr) {
    182       return nullptr;
    183     }
    184     // CheckObjectAlloc can cause thread suspension which means we may now be instrumented.
    185     return klass->Alloc</*kInstrumented*/true>(
    186         self,
    187         Runtime::Current()->GetHeap()->GetCurrentAllocator());
    188   }
    189   DCHECK(klass != nullptr);
    190   return klass->Alloc<kInstrumented>(self, allocator_type);
    191 }
    192 
    193 // Given the context of a calling Method and a resolved class, create an instance.
    194 template <bool kInstrumented>
    195 ALWAYS_INLINE
    196 inline mirror::Object* AllocObjectFromCodeResolved(mirror::Class* klass,
    197                                                    Thread* self,
    198                                                    gc::AllocatorType allocator_type) {
    199   DCHECK(klass != nullptr);
    200   bool slow_path = false;
    201   klass = CheckClassInitializedForObjectAlloc(klass, self, &slow_path);
    202   if (UNLIKELY(slow_path)) {
    203     if (klass == nullptr) {
    204       return nullptr;
    205     }
    206     gc::Heap* heap = Runtime::Current()->GetHeap();
    207     // Pass in false since the object cannot be finalizable.
    208     // CheckClassInitializedForObjectAlloc can cause thread suspension which means we may now be
    209     // instrumented.
    210     return klass->Alloc</*kInstrumented*/true, false>(self, heap->GetCurrentAllocator());
    211   }
    212   // Pass in false since the object cannot be finalizable.
    213   return klass->Alloc<kInstrumented, false>(self, allocator_type);
    214 }
    215 
    216 // Given the context of a calling Method and an initialized class, create an instance.
    217 template <bool kInstrumented>
    218 ALWAYS_INLINE
    219 inline mirror::Object* AllocObjectFromCodeInitialized(mirror::Class* klass,
    220                                                       Thread* self,
    221                                                       gc::AllocatorType allocator_type) {
    222   DCHECK(klass != nullptr);
    223   // Pass in false since the object cannot be finalizable.
    224   return klass->Alloc<kInstrumented, false>(self, allocator_type);
    225 }
    226 
    227 
    228 template <bool kAccessCheck>
    229 ALWAYS_INLINE
    230 inline mirror::Class* CheckArrayAlloc(uint32_t type_idx,
    231                                       int32_t component_count,
    232                                       ArtMethod* method,
    233                                       bool* slow_path) {
    234   if (UNLIKELY(component_count < 0)) {
    235     ThrowNegativeArraySizeException(component_count);
    236     *slow_path = true;
    237     return nullptr;  // Failure
    238   }
    239   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
    240   size_t pointer_size = class_linker->GetImagePointerSize();
    241   mirror::Class* klass = method->GetDexCacheResolvedType<false>(type_idx, pointer_size);
    242   if (UNLIKELY(klass == nullptr)) {  // Not in dex cache so try to resolve
    243     klass = class_linker->ResolveType(type_idx, method);
    244     *slow_path = true;
    245     if (klass == nullptr) {  // Error
    246       DCHECK(Thread::Current()->IsExceptionPending());
    247       return nullptr;  // Failure
    248     }
    249     CHECK(klass->IsArrayClass()) << PrettyClass(klass);
    250   }
    251   if (kAccessCheck) {
    252     mirror::Class* referrer = method->GetDeclaringClass();
    253     if (UNLIKELY(!referrer->CanAccess(klass))) {
    254       ThrowIllegalAccessErrorClass(referrer, klass);
    255       *slow_path = true;
    256       return nullptr;  // Failure
    257     }
    258   }
    259   return klass;
    260 }
    261 
    262 // Given the context of a calling Method, use its DexCache to resolve a type to an array Class. If
    263 // it cannot be resolved, throw an error. If it can, use it to create an array.
    264 // When verification/compiler hasn't been able to verify access, optionally perform an access
    265 // check.
    266 template <bool kAccessCheck, bool kInstrumented>
    267 ALWAYS_INLINE
    268 inline mirror::Array* AllocArrayFromCode(uint32_t type_idx,
    269                                          int32_t component_count,
    270                                          ArtMethod* method,
    271                                          Thread* self,
    272                                          gc::AllocatorType allocator_type) {
    273   bool slow_path = false;
    274   mirror::Class* klass = CheckArrayAlloc<kAccessCheck>(type_idx, component_count, method,
    275                                                        &slow_path);
    276   if (UNLIKELY(slow_path)) {
    277     if (klass == nullptr) {
    278       return nullptr;
    279     }
    280     gc::Heap* heap = Runtime::Current()->GetHeap();
    281     // CheckArrayAlloc can cause thread suspension which means we may now be instrumented.
    282     return mirror::Array::Alloc</*kInstrumented*/true>(self,
    283                                                        klass,
    284                                                        component_count,
    285                                                        klass->GetComponentSizeShift(),
    286                                                        heap->GetCurrentAllocator());
    287   }
    288   return mirror::Array::Alloc<kInstrumented>(self, klass, component_count,
    289                                              klass->GetComponentSizeShift(), allocator_type);
    290 }
    291 
    292 template <bool kAccessCheck, bool kInstrumented>
    293 ALWAYS_INLINE
    294 inline mirror::Array* AllocArrayFromCodeResolved(mirror::Class* klass,
    295                                                  int32_t component_count,
    296                                                  ArtMethod* method,
    297                                                  Thread* self,
    298                                                  gc::AllocatorType allocator_type) {
    299   DCHECK(klass != nullptr);
    300   if (UNLIKELY(component_count < 0)) {
    301     ThrowNegativeArraySizeException(component_count);
    302     return nullptr;  // Failure
    303   }
    304   if (kAccessCheck) {
    305     mirror::Class* referrer = method->GetDeclaringClass();
    306     if (UNLIKELY(!referrer->CanAccess(klass))) {
    307       ThrowIllegalAccessErrorClass(referrer, klass);
    308       return nullptr;  // Failure
    309     }
    310   }
    311   // No need to retry a slow-path allocation as the above code won't cause a GC or thread
    312   // suspension.
    313   return mirror::Array::Alloc<kInstrumented>(self, klass, component_count,
    314                                              klass->GetComponentSizeShift(), allocator_type);
    315 }
    316 
    317 template<FindFieldType type, bool access_check>
    318 inline ArtField* FindFieldFromCode(uint32_t field_idx,
    319                                    ArtMethod* referrer,
    320                                    Thread* self,
    321                                    size_t expected_size) REQUIRES(!Roles::uninterruptible_) {
    322   bool is_primitive;
    323   bool is_set;
    324   bool is_static;
    325   switch (type) {
    326     case InstanceObjectRead:     is_primitive = false; is_set = false; is_static = false; break;
    327     case InstanceObjectWrite:    is_primitive = false; is_set = true;  is_static = false; break;
    328     case InstancePrimitiveRead:  is_primitive = true;  is_set = false; is_static = false; break;
    329     case InstancePrimitiveWrite: is_primitive = true;  is_set = true;  is_static = false; break;
    330     case StaticObjectRead:       is_primitive = false; is_set = false; is_static = true;  break;
    331     case StaticObjectWrite:      is_primitive = false; is_set = true;  is_static = true;  break;
    332     case StaticPrimitiveRead:    is_primitive = true;  is_set = false; is_static = true;  break;
    333     case StaticPrimitiveWrite:   // Keep GCC happy by having a default handler, fall-through.
    334     default:                     is_primitive = true;  is_set = true;  is_static = true;  break;
    335   }
    336   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
    337 
    338   ArtField* resolved_field;
    339   if (access_check) {
    340     // Slow path: According to JLS 13.4.8, a linkage error may occur if a compile-time
    341     // qualifying type of a field and the resolved run-time qualifying type of a field differed
    342     // in their static-ness.
    343     //
    344     // In particular, don't assume the dex instruction already correctly knows if the
    345     // real field is static or not. The resolution must not be aware of this.
    346     ArtMethod* method = referrer->GetInterfaceMethodIfProxy(sizeof(void*));
    347 
    348     StackHandleScope<2> hs(self);
    349     Handle<mirror::DexCache> h_dex_cache(hs.NewHandle(method->GetDexCache()));
    350     Handle<mirror::ClassLoader> h_class_loader(hs.NewHandle(method->GetClassLoader()));
    351 
    352     resolved_field = class_linker->ResolveFieldJLS(*method->GetDexFile(),
    353                                                    field_idx,
    354                                                    h_dex_cache,
    355                                                    h_class_loader);
    356   } else {
    357     // Fast path: Verifier already would've called ResolveFieldJLS and we wouldn't
    358     // be executing here if there was a static/non-static mismatch.
    359     resolved_field = class_linker->ResolveField(field_idx, referrer, is_static);
    360   }
    361 
    362   if (UNLIKELY(resolved_field == nullptr)) {
    363     DCHECK(self->IsExceptionPending());  // Throw exception and unwind.
    364     return nullptr;  // Failure.
    365   }
    366   mirror::Class* fields_class = resolved_field->GetDeclaringClass();
    367   if (access_check) {
    368     if (UNLIKELY(resolved_field->IsStatic() != is_static)) {
    369       ThrowIncompatibleClassChangeErrorField(resolved_field, is_static, referrer);
    370       return nullptr;
    371     }
    372     mirror::Class* referring_class = referrer->GetDeclaringClass();
    373     if (UNLIKELY(!referring_class->CheckResolvedFieldAccess(fields_class, resolved_field,
    374                                                             field_idx))) {
    375       DCHECK(self->IsExceptionPending());  // Throw exception and unwind.
    376       return nullptr;  // Failure.
    377     }
    378     if (UNLIKELY(is_set && resolved_field->IsFinal() && (fields_class != referring_class))) {
    379       ThrowIllegalAccessErrorFinalField(referrer, resolved_field);
    380       return nullptr;  // Failure.
    381     } else {
    382       if (UNLIKELY(resolved_field->IsPrimitiveType() != is_primitive ||
    383                    resolved_field->FieldSize() != expected_size)) {
    384         self->ThrowNewExceptionF("Ljava/lang/NoSuchFieldError;",
    385                                  "Attempted read of %zd-bit %s on field '%s'",
    386                                  expected_size * (32 / sizeof(int32_t)),
    387                                  is_primitive ? "primitive" : "non-primitive",
    388                                  PrettyField(resolved_field, true).c_str());
    389         return nullptr;  // Failure.
    390       }
    391     }
    392   }
    393   if (!is_static) {
    394     // instance fields must be being accessed on an initialized class
    395     return resolved_field;
    396   } else {
    397     // If the class is initialized we're done.
    398     if (LIKELY(fields_class->IsInitialized())) {
    399       return resolved_field;
    400     } else {
    401       StackHandleScope<1> hs(self);
    402       Handle<mirror::Class> h_class(hs.NewHandle(fields_class));
    403       if (LIKELY(class_linker->EnsureInitialized(self, h_class, true, true))) {
    404         // Otherwise let's ensure the class is initialized before resolving the field.
    405         return resolved_field;
    406       }
    407       DCHECK(self->IsExceptionPending());  // Throw exception and unwind
    408       return nullptr;  // Failure.
    409     }
    410   }
    411 }
    412 
    413 // Explicit template declarations of FindFieldFromCode for all field access types.
    414 #define EXPLICIT_FIND_FIELD_FROM_CODE_TEMPLATE_DECL(_type, _access_check) \
    415 template SHARED_REQUIRES(Locks::mutator_lock_) ALWAYS_INLINE \
    416 ArtField* FindFieldFromCode<_type, _access_check>(uint32_t field_idx, \
    417                                                   ArtMethod* referrer, \
    418                                                   Thread* self, size_t expected_size) \
    419 
    420 #define EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(_type) \
    421     EXPLICIT_FIND_FIELD_FROM_CODE_TEMPLATE_DECL(_type, false); \
    422     EXPLICIT_FIND_FIELD_FROM_CODE_TEMPLATE_DECL(_type, true)
    423 
    424 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(InstanceObjectRead);
    425 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(InstanceObjectWrite);
    426 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(InstancePrimitiveRead);
    427 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(InstancePrimitiveWrite);
    428 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(StaticObjectRead);
    429 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(StaticObjectWrite);
    430 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(StaticPrimitiveRead);
    431 EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL(StaticPrimitiveWrite);
    432 
    433 #undef EXPLICIT_FIND_FIELD_FROM_CODE_TYPED_TEMPLATE_DECL
    434 #undef EXPLICIT_FIND_FIELD_FROM_CODE_TEMPLATE_DECL
    435 
    436 template<InvokeType type, bool access_check>
    437 inline ArtMethod* FindMethodFromCode(uint32_t method_idx, mirror::Object** this_object,
    438                                      ArtMethod* referrer, Thread* self) {
    439   ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
    440   ArtMethod* resolved_method = class_linker->GetResolvedMethod(method_idx, referrer);
    441   if (resolved_method == nullptr) {
    442     StackHandleScope<1> hs(self);
    443     mirror::Object* null_this = nullptr;
    444     HandleWrapper<mirror::Object> h_this(
    445         hs.NewHandleWrapper(type == kStatic ? &null_this : this_object));
    446     constexpr ClassLinker::ResolveMode resolve_mode =
    447         access_check ? ClassLinker::kForceICCECheck
    448                      : ClassLinker::kNoICCECheckForCache;
    449     resolved_method = class_linker->ResolveMethod<resolve_mode>(self, method_idx, referrer, type);
    450   }
    451   if (UNLIKELY(resolved_method == nullptr)) {
    452     DCHECK(self->IsExceptionPending());  // Throw exception and unwind.
    453     return nullptr;  // Failure.
    454   } else if (UNLIKELY(*this_object == nullptr && type != kStatic)) {
    455     if (UNLIKELY(resolved_method->GetDeclaringClass()->IsStringClass() &&
    456                  resolved_method->IsConstructor())) {
    457       // Hack for String init:
    458       //
    459       // We assume that the input of String.<init> in verified code is always
    460       // an unitialized reference. If it is a null constant, it must have been
    461       // optimized out by the compiler. Do not throw NullPointerException.
    462     } else {
    463       // Maintain interpreter-like semantics where NullPointerException is thrown
    464       // after potential NoSuchMethodError from class linker.
    465       ThrowNullPointerExceptionForMethodAccess(method_idx, type);
    466       return nullptr;  // Failure.
    467     }
    468   } else if (access_check) {
    469     mirror::Class* methods_class = resolved_method->GetDeclaringClass();
    470     bool can_access_resolved_method =
    471         referrer->GetDeclaringClass()->CheckResolvedMethodAccess<type>(methods_class,
    472                                                                        resolved_method,
    473                                                                        method_idx);
    474     if (UNLIKELY(!can_access_resolved_method)) {
    475       DCHECK(self->IsExceptionPending());  // Throw exception and unwind.
    476       return nullptr;  // Failure.
    477     }
    478     // Incompatible class change should have been handled in resolve method.
    479     if (UNLIKELY(resolved_method->CheckIncompatibleClassChange(type))) {
    480       ThrowIncompatibleClassChangeError(type, resolved_method->GetInvokeType(), resolved_method,
    481                                         referrer);
    482       return nullptr;  // Failure.
    483     }
    484   }
    485   switch (type) {
    486     case kStatic:
    487     case kDirect:
    488       return resolved_method;
    489     case kVirtual: {
    490       mirror::Class* klass = (*this_object)->GetClass();
    491       uint16_t vtable_index = resolved_method->GetMethodIndex();
    492       if (access_check &&
    493           (!klass->HasVTable() ||
    494            vtable_index >= static_cast<uint32_t>(klass->GetVTableLength()))) {
    495         // Behavior to agree with that of the verifier.
    496         ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(),
    497                                resolved_method->GetName(), resolved_method->GetSignature());
    498         return nullptr;  // Failure.
    499       }
    500       DCHECK(klass->HasVTable()) << PrettyClass(klass);
    501       return klass->GetVTableEntry(vtable_index, class_linker->GetImagePointerSize());
    502     }
    503     case kSuper: {
    504       // TODO This lookup is quite slow.
    505       // NB This is actually quite tricky to do any other way. We cannot use GetDeclaringClass since
    506       //    that will actually not be what we want in some cases where there are miranda methods or
    507       //    defaults. What we actually need is a GetContainingClass that says which classes virtuals
    508       //    this method is coming from.
    509       mirror::Class* referring_class = referrer->GetDeclaringClass();
    510       uint16_t method_type_idx = referring_class->GetDexFile().GetMethodId(method_idx).class_idx_;
    511       mirror::Class* method_reference_class = class_linker->ResolveType(method_type_idx, referrer);
    512       if (UNLIKELY(method_reference_class == nullptr)) {
    513         // Bad type idx.
    514         CHECK(self->IsExceptionPending());
    515         return nullptr;
    516       } else if (!method_reference_class->IsInterface()) {
    517         // It is not an interface. If the referring class is in the class hierarchy of the
    518         // referenced class in the bytecode, we use its super class. Otherwise, we throw
    519         // a NoSuchMethodError.
    520         mirror::Class* super_class = nullptr;
    521         if (method_reference_class->IsAssignableFrom(referring_class)) {
    522           super_class = referring_class->GetSuperClass();
    523         }
    524         uint16_t vtable_index = resolved_method->GetMethodIndex();
    525         if (access_check) {
    526           // Check existence of super class.
    527           if (super_class == nullptr ||
    528               !super_class->HasVTable() ||
    529               vtable_index >= static_cast<uint32_t>(super_class->GetVTableLength())) {
    530             // Behavior to agree with that of the verifier.
    531             ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(),
    532                                    resolved_method->GetName(), resolved_method->GetSignature());
    533             return nullptr;  // Failure.
    534           }
    535         }
    536         DCHECK(super_class != nullptr);
    537         DCHECK(super_class->HasVTable());
    538         return super_class->GetVTableEntry(vtable_index, class_linker->GetImagePointerSize());
    539       } else {
    540         // It is an interface.
    541         if (access_check) {
    542           if (!method_reference_class->IsAssignableFrom((*this_object)->GetClass())) {
    543             ThrowIncompatibleClassChangeErrorClassForInterfaceSuper(resolved_method,
    544                                                                     method_reference_class,
    545                                                                     *this_object,
    546                                                                     referrer);
    547             return nullptr;  // Failure.
    548           }
    549         }
    550         // TODO We can do better than this for a (compiled) fastpath.
    551         ArtMethod* result = method_reference_class->FindVirtualMethodForInterfaceSuper(
    552             resolved_method, class_linker->GetImagePointerSize());
    553         // Throw an NSME if nullptr;
    554         if (result == nullptr) {
    555           ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(),
    556                                  resolved_method->GetName(), resolved_method->GetSignature());
    557         }
    558         return result;
    559       }
    560     }
    561     case kInterface: {
    562       uint32_t imt_index = resolved_method->GetDexMethodIndex() % ImTable::kSize;
    563       size_t pointer_size = class_linker->GetImagePointerSize();
    564       ArtMethod* imt_method = (*this_object)->GetClass()->GetImt(pointer_size)->
    565           Get(imt_index, pointer_size);
    566       if (!imt_method->IsRuntimeMethod()) {
    567         if (kIsDebugBuild) {
    568           mirror::Class* klass = (*this_object)->GetClass();
    569           ArtMethod* method = klass->FindVirtualMethodForInterface(
    570               resolved_method, class_linker->GetImagePointerSize());
    571           CHECK_EQ(imt_method, method) << PrettyMethod(resolved_method) << " / " <<
    572               PrettyMethod(imt_method) << " / " << PrettyMethod(method) << " / " <<
    573               PrettyClass(klass);
    574         }
    575         return imt_method;
    576       } else {
    577         ArtMethod* interface_method = (*this_object)->GetClass()->FindVirtualMethodForInterface(
    578             resolved_method, class_linker->GetImagePointerSize());
    579         if (UNLIKELY(interface_method == nullptr)) {
    580           ThrowIncompatibleClassChangeErrorClassForInterfaceDispatch(resolved_method,
    581                                                                      *this_object, referrer);
    582           return nullptr;  // Failure.
    583         }
    584         return interface_method;
    585       }
    586     }
    587     default:
    588       LOG(FATAL) << "Unknown invoke type " << type;
    589       return nullptr;  // Failure.
    590   }
    591 }
    592 
    593 // Explicit template declarations of FindMethodFromCode for all invoke types.
    594 #define EXPLICIT_FIND_METHOD_FROM_CODE_TEMPLATE_DECL(_type, _access_check)                 \
    595   template SHARED_REQUIRES(Locks::mutator_lock_) ALWAYS_INLINE                       \
    596   ArtMethod* FindMethodFromCode<_type, _access_check>(uint32_t method_idx,         \
    597                                                       mirror::Object** this_object, \
    598                                                       ArtMethod* referrer, \
    599                                                       Thread* self)
    600 #define EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(_type) \
    601     EXPLICIT_FIND_METHOD_FROM_CODE_TEMPLATE_DECL(_type, false);   \
    602     EXPLICIT_FIND_METHOD_FROM_CODE_TEMPLATE_DECL(_type, true)
    603 
    604 EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(kStatic);
    605 EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(kDirect);
    606 EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(kVirtual);
    607 EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(kSuper);
    608 EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL(kInterface);
    609 
    610 #undef EXPLICIT_FIND_METHOD_FROM_CODE_TYPED_TEMPLATE_DECL
    611 #undef EXPLICIT_FIND_METHOD_FROM_CODE_TEMPLATE_DECL
    612 
    613 // Fast path field resolution that can't initialize classes or throw exceptions.
    614 inline ArtField* FindFieldFast(uint32_t field_idx, ArtMethod* referrer, FindFieldType type,
    615                                size_t expected_size) {
    616   ArtField* resolved_field =
    617       referrer->GetDeclaringClass()->GetDexCache()->GetResolvedField(field_idx, sizeof(void*));
    618   if (UNLIKELY(resolved_field == nullptr)) {
    619     return nullptr;
    620   }
    621   // Check for incompatible class change.
    622   bool is_primitive;
    623   bool is_set;
    624   bool is_static;
    625   switch (type) {
    626     case InstanceObjectRead:     is_primitive = false; is_set = false; is_static = false; break;
    627     case InstanceObjectWrite:    is_primitive = false; is_set = true;  is_static = false; break;
    628     case InstancePrimitiveRead:  is_primitive = true;  is_set = false; is_static = false; break;
    629     case InstancePrimitiveWrite: is_primitive = true;  is_set = true;  is_static = false; break;
    630     case StaticObjectRead:       is_primitive = false; is_set = false; is_static = true;  break;
    631     case StaticObjectWrite:      is_primitive = false; is_set = true;  is_static = true;  break;
    632     case StaticPrimitiveRead:    is_primitive = true;  is_set = false; is_static = true;  break;
    633     case StaticPrimitiveWrite:   is_primitive = true;  is_set = true;  is_static = true;  break;
    634     default:
    635       LOG(FATAL) << "UNREACHABLE";
    636       UNREACHABLE();
    637   }
    638   if (UNLIKELY(resolved_field->IsStatic() != is_static)) {
    639     // Incompatible class change.
    640     return nullptr;
    641   }
    642   mirror::Class* fields_class = resolved_field->GetDeclaringClass();
    643   if (is_static) {
    644     // Check class is initialized else fail so that we can contend to initialize the class with
    645     // other threads that may be racing to do this.
    646     if (UNLIKELY(!fields_class->IsInitialized())) {
    647       return nullptr;
    648     }
    649   }
    650   mirror::Class* referring_class = referrer->GetDeclaringClass();
    651   if (UNLIKELY(!referring_class->CanAccess(fields_class) ||
    652                !referring_class->CanAccessMember(fields_class, resolved_field->GetAccessFlags()) ||
    653                (is_set && resolved_field->IsFinal() && (fields_class != referring_class)))) {
    654     // Illegal access.
    655     return nullptr;
    656   }
    657   if (UNLIKELY(resolved_field->IsPrimitiveType() != is_primitive ||
    658                resolved_field->FieldSize() != expected_size)) {
    659     return nullptr;
    660   }
    661   return resolved_field;
    662 }
    663 
    664 // Fast path method resolution that can't throw exceptions.
    665 inline ArtMethod* FindMethodFast(uint32_t method_idx, mirror::Object* this_object,
    666                                  ArtMethod* referrer, bool access_check, InvokeType type) {
    667   if (UNLIKELY(this_object == nullptr && type != kStatic)) {
    668     return nullptr;
    669   }
    670   mirror::Class* referring_class = referrer->GetDeclaringClass();
    671   ArtMethod* resolved_method =
    672       referring_class->GetDexCache()->GetResolvedMethod(method_idx, sizeof(void*));
    673   if (UNLIKELY(resolved_method == nullptr)) {
    674     return nullptr;
    675   }
    676   if (access_check) {
    677     // Check for incompatible class change errors and access.
    678     bool icce = resolved_method->CheckIncompatibleClassChange(type);
    679     if (UNLIKELY(icce)) {
    680       return nullptr;
    681     }
    682     mirror::Class* methods_class = resolved_method->GetDeclaringClass();
    683     if (UNLIKELY(!referring_class->CanAccess(methods_class) ||
    684                  !referring_class->CanAccessMember(methods_class,
    685                                                    resolved_method->GetAccessFlags()))) {
    686       // Potential illegal access, may need to refine the method's class.
    687       return nullptr;
    688     }
    689   }
    690   if (type == kInterface) {  // Most common form of slow path dispatch.
    691     return this_object->GetClass()->FindVirtualMethodForInterface(resolved_method, sizeof(void*));
    692   } else if (type == kStatic || type == kDirect) {
    693     return resolved_method;
    694   } else if (type == kSuper) {
    695     // TODO This lookup is rather slow.
    696     uint16_t method_type_idx = referring_class->GetDexFile().GetMethodId(method_idx).class_idx_;
    697     mirror::Class* method_reference_class =
    698         referring_class->GetDexCache()->GetResolvedType(method_type_idx);
    699     if (method_reference_class == nullptr) {
    700       // Need to do full type resolution...
    701       return nullptr;
    702     } else if (!method_reference_class->IsInterface()) {
    703       // It is not an interface. If the referring class is in the class hierarchy of the
    704       // referenced class in the bytecode, we use its super class. Otherwise, we cannot
    705       // resolve the method.
    706       if (!method_reference_class->IsAssignableFrom(referring_class)) {
    707         return nullptr;
    708       }
    709       mirror::Class* super_class = referring_class->GetSuperClass();
    710       if (resolved_method->GetMethodIndex() >= super_class->GetVTableLength()) {
    711         // The super class does not have the method.
    712         return nullptr;
    713       }
    714       return super_class->GetVTableEntry(resolved_method->GetMethodIndex(), sizeof(void*));
    715     } else {
    716       return method_reference_class->FindVirtualMethodForInterfaceSuper(
    717           resolved_method, sizeof(void*));
    718     }
    719   } else {
    720     DCHECK(type == kVirtual);
    721     return this_object->GetClass()->GetVTableEntry(
    722         resolved_method->GetMethodIndex(), sizeof(void*));
    723   }
    724 }
    725 
    726 inline mirror::Class* ResolveVerifyAndClinit(uint32_t type_idx, ArtMethod* referrer, Thread* self,
    727                                              bool can_run_clinit, bool verify_access) {
    728   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
    729   mirror::Class* klass = class_linker->ResolveType(type_idx, referrer);
    730   if (UNLIKELY(klass == nullptr)) {
    731     CHECK(self->IsExceptionPending());
    732     return nullptr;  // Failure - Indicate to caller to deliver exception
    733   }
    734   // Perform access check if necessary.
    735   mirror::Class* referring_class = referrer->GetDeclaringClass();
    736   if (verify_access && UNLIKELY(!referring_class->CanAccess(klass))) {
    737     ThrowIllegalAccessErrorClass(referring_class, klass);
    738     return nullptr;  // Failure - Indicate to caller to deliver exception
    739   }
    740   // If we're just implementing const-class, we shouldn't call <clinit>.
    741   if (!can_run_clinit) {
    742     return klass;
    743   }
    744   // If we are the <clinit> of this class, just return our storage.
    745   //
    746   // Do not set the DexCache InitializedStaticStorage, since that implies <clinit> has finished
    747   // running.
    748   if (klass == referring_class && referrer->IsConstructor() && referrer->IsStatic()) {
    749     return klass;
    750   }
    751   StackHandleScope<1> hs(self);
    752   Handle<mirror::Class> h_class(hs.NewHandle(klass));
    753   if (!class_linker->EnsureInitialized(self, h_class, true, true)) {
    754     CHECK(self->IsExceptionPending());
    755     return nullptr;  // Failure - Indicate to caller to deliver exception
    756   }
    757   return h_class.Get();
    758 }
    759 
    760 inline mirror::String* ResolveStringFromCode(ArtMethod* referrer, uint32_t string_idx) {
    761   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
    762   return class_linker->ResolveString(string_idx, referrer);
    763 }
    764 
    765 inline void UnlockJniSynchronizedMethod(jobject locked, Thread* self) {
    766   // Save any pending exception over monitor exit call.
    767   mirror::Throwable* saved_exception = nullptr;
    768   if (UNLIKELY(self->IsExceptionPending())) {
    769     saved_exception = self->GetException();
    770     self->ClearException();
    771   }
    772   // Decode locked object and unlock, before popping local references.
    773   self->DecodeJObject(locked)->MonitorExit(self);
    774   if (UNLIKELY(self->IsExceptionPending())) {
    775     LOG(FATAL) << "Synchronized JNI code returning with an exception:\n"
    776         << saved_exception->Dump()
    777         << "\nEncountered second exception during implicit MonitorExit:\n"
    778         << self->GetException()->Dump();
    779   }
    780   // Restore pending exception.
    781   if (saved_exception != nullptr) {
    782     self->SetException(saved_exception);
    783   }
    784 }
    785 
    786 template <typename INT_TYPE, typename FLOAT_TYPE>
    787 inline INT_TYPE art_float_to_integral(FLOAT_TYPE f) {
    788   const INT_TYPE kMaxInt = static_cast<INT_TYPE>(std::numeric_limits<INT_TYPE>::max());
    789   const INT_TYPE kMinInt = static_cast<INT_TYPE>(std::numeric_limits<INT_TYPE>::min());
    790   const FLOAT_TYPE kMaxIntAsFloat = static_cast<FLOAT_TYPE>(kMaxInt);
    791   const FLOAT_TYPE kMinIntAsFloat = static_cast<FLOAT_TYPE>(kMinInt);
    792   if (LIKELY(f > kMinIntAsFloat)) {
    793      if (LIKELY(f < kMaxIntAsFloat)) {
    794        return static_cast<INT_TYPE>(f);
    795      } else {
    796        return kMaxInt;
    797      }
    798   } else {
    799     return (f != f) ? 0 : kMinInt;  // f != f implies NaN
    800   }
    801 }
    802 
    803 }  // namespace art
    804 
    805 #endif  // ART_RUNTIME_ENTRYPOINTS_ENTRYPOINT_UTILS_INL_H_
    806