1 /*
2  * Copyright (C) 2018 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 #include "var_handles.h"
18 
19 #include "common_throws.h"
20 #include "dex/dex_instruction.h"
21 #include "handle.h"
22 #include "method_handles-inl.h"
23 #include "mirror/method_type-inl.h"
24 #include "mirror/var_handle.h"
25 
26 namespace art {
27 
28 namespace {
29 
VarHandleInvokeAccessorWithConversions(Thread * self,ShadowFrame & shadow_frame,Handle<mirror::VarHandle> var_handle,Handle<mirror::MethodType> callsite_type,const mirror::VarHandle::AccessMode access_mode,const InstructionOperands * const operands,JValue * result)30 bool VarHandleInvokeAccessorWithConversions(Thread* self,
31                                             ShadowFrame& shadow_frame,
32                                             Handle<mirror::VarHandle> var_handle,
33                                             Handle<mirror::MethodType> callsite_type,
34                                             const mirror::VarHandle::AccessMode access_mode,
35                                             const InstructionOperands* const operands,
36                                             JValue* result)
37     REQUIRES_SHARED(Locks::mutator_lock_) {
38   StackHandleScope<1> hs(self);
39   Handle<mirror::MethodType> accessor_type(hs.NewHandle(
40       var_handle->GetMethodTypeForAccessMode(self, access_mode)));
41   const size_t num_vregs = accessor_type->NumberOfVRegs();
42   const int num_params = accessor_type->GetPTypes()->GetLength();
43   ShadowFrameAllocaUniquePtr accessor_frame =
44       CREATE_SHADOW_FRAME(num_vregs, nullptr, shadow_frame.GetMethod(), shadow_frame.GetDexPC());
45   ShadowFrameGetter getter(shadow_frame, operands);
46   static const uint32_t kFirstDestinationReg = 0;
47   ShadowFrameSetter setter(accessor_frame.get(), kFirstDestinationReg);
48   if (!PerformConversions(self, callsite_type, accessor_type, &getter, &setter, num_params)) {
49     return false;
50   }
51   RangeInstructionOperands accessor_operands(kFirstDestinationReg,
52                                              kFirstDestinationReg + num_vregs);
53   if (!var_handle->Access(access_mode, accessor_frame.get(), &accessor_operands, result)) {
54     return false;
55   }
56   return ConvertReturnValue(callsite_type, accessor_type, result);
57 }
58 
59 }  // namespace
60 
VarHandleInvokeAccessor(Thread * self,ShadowFrame & shadow_frame,Handle<mirror::VarHandle> var_handle,Handle<mirror::MethodType> callsite_type,const mirror::VarHandle::AccessMode access_mode,const InstructionOperands * const operands,JValue * result)61 bool VarHandleInvokeAccessor(Thread* self,
62                              ShadowFrame& shadow_frame,
63                              Handle<mirror::VarHandle> var_handle,
64                              Handle<mirror::MethodType> callsite_type,
65                              const mirror::VarHandle::AccessMode access_mode,
66                              const InstructionOperands* const operands,
67                              JValue* result) {
68   if (var_handle.IsNull()) {
69     ThrowNullPointerExceptionFromDexPC();
70     return false;
71   }
72 
73   if (!var_handle->IsAccessModeSupported(access_mode)) {
74     ThrowUnsupportedOperationException();
75     return false;
76   }
77 
78   mirror::VarHandle::MatchKind match_kind =
79       var_handle->GetMethodTypeMatchForAccessMode(access_mode, callsite_type.Get());
80   if (LIKELY(match_kind == mirror::VarHandle::MatchKind::kExact)) {
81     return var_handle->Access(access_mode, &shadow_frame, operands, result);
82   } else if (match_kind == mirror::VarHandle::MatchKind::kWithConversions) {
83     return VarHandleInvokeAccessorWithConversions(self,
84                                                   shadow_frame,
85                                                   var_handle,
86                                                   callsite_type,
87                                                   access_mode,
88                                                   operands,
89                                                   result);
90   } else {
91     DCHECK_EQ(match_kind, mirror::VarHandle::MatchKind::kNone);
92     ThrowWrongMethodTypeException(var_handle->PrettyDescriptorForAccessMode(access_mode),
93                                   callsite_type->PrettyDescriptor());
94     return false;
95   }
96 }
97 
98 }  // namespace art
99