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_INL_H_
18 #define ART_RUNTIME_UTILS_DEX_CACHE_ARRAYS_LAYOUT_INL_H_
19 
20 #include "dex_cache_arrays_layout.h"
21 
22 #include "base/bit_utils.h"
23 #include "base/logging.h"
24 #include "gc_root.h"
25 #include "globals.h"
26 #include "primitive.h"
27 
28 namespace art {
29 
DexCacheArraysLayout(size_t pointer_size,const DexFile::Header & header)30 inline DexCacheArraysLayout::DexCacheArraysLayout(size_t pointer_size,
31                                                   const DexFile::Header& header)
32     : pointer_size_(pointer_size),
33       /* types_offset_ is always 0u, so it's constexpr */
34       methods_offset_(
35           RoundUp(types_offset_ + TypesSize(header.type_ids_size_), MethodsAlignment())),
36       strings_offset_(
37           RoundUp(methods_offset_ + MethodsSize(header.method_ids_size_), StringsAlignment())),
38       fields_offset_(
39           RoundUp(strings_offset_ + StringsSize(header.string_ids_size_), FieldsAlignment())),
40       size_(
41           RoundUp(fields_offset_ + FieldsSize(header.field_ids_size_), Alignment())) {
42   DCHECK(ValidPointerSize(pointer_size)) << pointer_size;
43 }
44 
DexCacheArraysLayout(size_t pointer_size,const DexFile * dex_file)45 inline DexCacheArraysLayout::DexCacheArraysLayout(size_t pointer_size, const DexFile* dex_file)
46     : DexCacheArraysLayout(pointer_size, dex_file->GetHeader()) {
47 }
48 
Alignment()49 inline size_t DexCacheArraysLayout::Alignment() const {
50   // GcRoot<> alignment is 4, i.e. lower than or equal to the pointer alignment.
51   static_assert(alignof(GcRoot<mirror::Class>) == 4, "Expecting alignof(GcRoot<>) == 4");
52   static_assert(alignof(GcRoot<mirror::String>) == 4, "Expecting alignof(GcRoot<>) == 4");
53   DCHECK(pointer_size_ == 4u || pointer_size_ == 8u);
54   // Pointer alignment is the same as pointer size.
55   return pointer_size_;
56 }
57 
TypeOffset(uint32_t type_idx)58 inline size_t DexCacheArraysLayout::TypeOffset(uint32_t type_idx) const {
59   return types_offset_ + ElementOffset(sizeof(GcRoot<mirror::Class>), type_idx);
60 }
61 
TypesSize(size_t num_elements)62 inline size_t DexCacheArraysLayout::TypesSize(size_t num_elements) const {
63   // App image patching relies on having enough room for a forwarding pointer in the types array.
64   // See FixupArtMethodArrayVisitor and ClassLinker::AddImageSpace.
65   return std::max(ArraySize(sizeof(GcRoot<mirror::Class>), num_elements), pointer_size_);
66 }
67 
TypesAlignment()68 inline size_t DexCacheArraysLayout::TypesAlignment() const {
69   return alignof(GcRoot<mirror::Class>);
70 }
71 
MethodOffset(uint32_t method_idx)72 inline size_t DexCacheArraysLayout::MethodOffset(uint32_t method_idx) const {
73   return methods_offset_ + ElementOffset(pointer_size_, method_idx);
74 }
75 
MethodsSize(size_t num_elements)76 inline size_t DexCacheArraysLayout::MethodsSize(size_t num_elements) const {
77   // App image patching relies on having enough room for a forwarding pointer in the methods array.
78   return std::max(ArraySize(pointer_size_, num_elements), pointer_size_);
79 }
80 
MethodsAlignment()81 inline size_t DexCacheArraysLayout::MethodsAlignment() const {
82   return pointer_size_;
83 }
84 
StringOffset(uint32_t string_idx)85 inline size_t DexCacheArraysLayout::StringOffset(uint32_t string_idx) const {
86   return strings_offset_ + ElementOffset(sizeof(GcRoot<mirror::String>), string_idx);
87 }
88 
StringsSize(size_t num_elements)89 inline size_t DexCacheArraysLayout::StringsSize(size_t num_elements) const {
90   return ArraySize(sizeof(GcRoot<mirror::String>), num_elements);
91 }
92 
StringsAlignment()93 inline size_t DexCacheArraysLayout::StringsAlignment() const {
94   return alignof(GcRoot<mirror::String>);
95 }
96 
FieldOffset(uint32_t field_idx)97 inline size_t DexCacheArraysLayout::FieldOffset(uint32_t field_idx) const {
98   return fields_offset_ + ElementOffset(pointer_size_, field_idx);
99 }
100 
FieldsSize(size_t num_elements)101 inline size_t DexCacheArraysLayout::FieldsSize(size_t num_elements) const {
102   return ArraySize(pointer_size_, num_elements);
103 }
104 
FieldsAlignment()105 inline size_t DexCacheArraysLayout::FieldsAlignment() const {
106   return pointer_size_;
107 }
108 
ElementOffset(size_t element_size,uint32_t idx)109 inline size_t DexCacheArraysLayout::ElementOffset(size_t element_size, uint32_t idx) {
110   return element_size * idx;
111 }
112 
ArraySize(size_t element_size,uint32_t num_elements)113 inline size_t DexCacheArraysLayout::ArraySize(size_t element_size, uint32_t num_elements) {
114   return element_size * num_elements;
115 }
116 
117 }  // namespace art
118 
119 #endif  // ART_RUNTIME_UTILS_DEX_CACHE_ARRAYS_LAYOUT_INL_H_
120