1 /*
2  * Copyright (C) 2015 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_UTILS_DEX_CACHE_ARRAYS_LAYOUT_H_
18 #define ART_RUNTIME_UTILS_DEX_CACHE_ARRAYS_LAYOUT_H_
19 
20 #include "dex/dex_file.h"
21 #include "dex/dex_file_types.h"
22 
23 namespace art {
24 
25 /**
26  * @class DexCacheArraysLayout
27  * @details This class provides the layout information for the type, method, field and
28  * string arrays for a DexCache with a fixed arrays' layout (such as in the boot image),
29  */
30 class DexCacheArraysLayout {
31  public:
32   // Construct an invalid layout.
DexCacheArraysLayout()33   DexCacheArraysLayout()
34       : /* types_offset_ is always 0u */
35         pointer_size_(kRuntimePointerSize),
36         methods_offset_(0u),
37         strings_offset_(0u),
38         fields_offset_(0u),
39         method_types_offset_(0u),
40         call_sites_offset_(0u),
41         size_(0u) {
42   }
43 
44   // Construct a layout for a particular dex file header.
45   DexCacheArraysLayout(PointerSize pointer_size,
46                        const DexFile::Header& header,
47                        uint32_t num_call_sites);
48 
49   // Construct a layout for a particular dex file.
50   DexCacheArraysLayout(PointerSize pointer_size, const DexFile* dex_file);
51 
Valid()52   bool Valid() const {
53     return Size() != 0u;
54   }
55 
Size()56   size_t Size() const {
57     return size_;
58   }
59 
60   size_t Alignment() const;
61 
62   static constexpr size_t Alignment(PointerSize pointer_size);
63 
TypesOffset()64   size_t TypesOffset() const {
65     return types_offset_;
66   }
67 
68   size_t TypeOffset(dex::TypeIndex type_idx) const;
69 
70   size_t TypesSize(size_t num_elements) const;
71 
72   size_t TypesAlignment() const;
73 
MethodsOffset()74   size_t MethodsOffset() const {
75     return methods_offset_;
76   }
77 
78   size_t MethodOffset(uint32_t method_idx) const;
79 
80   size_t MethodsSize(size_t num_elements) const;
81 
82   size_t MethodsAlignment() const;
83 
StringsOffset()84   size_t StringsOffset() const {
85     return strings_offset_;
86   }
87 
88   size_t StringOffset(uint32_t string_idx) const;
89 
90   size_t StringsSize(size_t num_elements) const;
91 
92   size_t StringsAlignment() const;
93 
FieldsOffset()94   size_t FieldsOffset() const {
95     return fields_offset_;
96   }
97 
98   size_t FieldOffset(uint32_t field_idx) const;
99 
100   size_t FieldsSize(size_t num_elements) const;
101 
102   size_t FieldsAlignment() const;
103 
MethodTypesOffset()104   size_t MethodTypesOffset() const {
105     return method_types_offset_;
106   }
107 
108   size_t MethodTypesSize(size_t num_elements) const;
109 
110   size_t MethodTypesAlignment() const;
111 
CallSitesOffset()112   size_t CallSitesOffset() const {
113     return call_sites_offset_;
114   }
115 
116   size_t CallSitesSize(size_t num_elements) const;
117 
118   size_t CallSitesAlignment() const;
119 
120  private:
121   static constexpr size_t types_offset_ = 0u;
122   const PointerSize pointer_size_;  // Must be first for construction initialization order.
123   const size_t methods_offset_;
124   const size_t strings_offset_;
125   const size_t fields_offset_;
126   const size_t method_types_offset_;
127   const size_t call_sites_offset_;
128   const size_t size_;
129 
130   static size_t ElementOffset(PointerSize element_size, uint32_t idx);
131 
132   static size_t ArraySize(PointerSize element_size, uint32_t num_elements);
133   static size_t PairArraySize(PointerSize element_size, uint32_t num_elements);
134 };
135 
136 }  // namespace art
137 
138 #endif  // ART_RUNTIME_UTILS_DEX_CACHE_ARRAYS_LAYOUT_H_
139