method_helper.h revision cb6b0f31ede2275e79e6199ec391147585a37a2a 
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_METHOD_HELPER_H_
18#define ART_RUNTIME_METHOD_HELPER_H_
19
20#include "base/macros.h"
21#include "handle.h"
22#include "mirror/art_method.h"
23#include "primitive.h"
24
25namespace art {
26
27class MethodHelper {
28 public:
29  explicit MethodHelper(Handle<mirror::ArtMethod> m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
30      : method_(m), shorty_(nullptr), shorty_len_(0) {
31    SetMethod(m.Get());
32  }
33
34  void ChangeMethod(mirror::ArtMethod* new_m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
35    DCHECK(new_m != nullptr);
36    SetMethod(new_m);
37    shorty_ = nullptr;
38  }
39
40  mirror::ArtMethod* GetMethod() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
41    return method_->GetInterfaceMethodIfProxy();
42  }
43
44  mirror::String* GetNameAsString(Thread* self) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
45
46  const char* GetShorty() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
47    const char* result = shorty_;
48    if (result == nullptr) {
49      result = method_->GetShorty(&shorty_len_);
50      shorty_ = result;
51    }
52    return result;
53  }
54
55  uint32_t GetShortyLength() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
56    if (shorty_ == nullptr) {
57      GetShorty();
58    }
59    return shorty_len_;
60  }
61
62  // Counts the number of references in the parameter list of the corresponding method.
63  // Note: Thus does _not_ include "this" for non-static methods.
64  uint32_t GetNumberOfReferenceArgsWithoutReceiver() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
65    const char* shorty = GetShorty();
66    uint32_t refs = 0;
67    for (uint32_t i = 1; i < shorty_len_ ; ++i) {
68      if (shorty[i] == 'L') {
69        refs++;
70      }
71    }
72
73    return refs;
74  }
75
76  // May cause thread suspension due to GetClassFromTypeIdx calling ResolveType this caused a large
77  // number of bugs at call sites.
78  mirror::Class* GetReturnType(bool resolve = true) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
79
80  size_t NumArgs() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
81    // "1 +" because the first in Args is the receiver.
82    // "- 1" because we don't count the return type.
83    return (method_->IsStatic() ? 0 : 1) + GetShortyLength() - 1;
84  }
85
86  // Get the primitive type associated with the given parameter.
87  Primitive::Type GetParamPrimitiveType(size_t param) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
88    CHECK_LT(param, NumArgs());
89    if (GetMethod()->IsStatic()) {
90      param++;  // 0th argument must skip return value at start of the shorty
91    } else if (param == 0) {
92      return Primitive::kPrimNot;
93    }
94    return Primitive::GetType(GetShorty()[param]);
95  }
96
97  // Is the specified parameter a long or double, where parameter 0 is 'this' for instance methods.
98  bool IsParamALongOrDouble(size_t param) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
99    Primitive::Type type = GetParamPrimitiveType(param);
100    return type == Primitive::kPrimLong || type == Primitive::kPrimDouble;
101  }
102
103  // Is the specified parameter a reference, where parameter 0 is 'this' for instance methods.
104  bool IsParamAReference(size_t param) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
105    return GetParamPrimitiveType(param) == Primitive::kPrimNot;
106  }
107
108  ALWAYS_INLINE bool HasSameNameAndSignature(MethodHelper* other)
109      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
110
111  bool HasSameSignatureWithDifferentClassLoaders(MethodHelper* other)
112      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
113
114  mirror::Class* GetClassFromTypeIdx(uint16_t type_idx, bool resolve = true)
115      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
116
117  mirror::String* ResolveString(uint32_t string_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
118
119  uint32_t FindDexMethodIndexInOtherDexFile(const DexFile& other_dexfile)
120      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
121
122  // The name_and_signature_idx MUST point to a MethodId with the same name and signature in the
123  // other_dexfile, such as the method index used to resolve this method in the other_dexfile.
124  uint32_t FindDexMethodIndexInOtherDexFile(const DexFile& other_dexfile,
125                                            uint32_t name_and_signature_idx)
126      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
127
128 private:
129  // Set the method_ field, for proxy methods looking up the interface method via the resolved
130  // methods table.
131  void SetMethod(mirror::ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
132    method_.Assign(method);
133  }
134
135  Handle<mirror::ArtMethod> method_;
136  const char* shorty_;
137  uint32_t shorty_len_;
138
139  DISALLOW_COPY_AND_ASSIGN(MethodHelper);
140};
141
142}  // namespace art
143
144#endif  // ART_RUNTIME_METHOD_HELPER_H_
145