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1 /*
2  * Copyright (C) 2022 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 "format/binary/ResEntryWriter.h"
18 
19 #include "ValueVisitor.h"
20 #include "androidfw/BigBuffer.h"
21 #include "androidfw/ResourceTypes.h"
22 #include "androidfw/Util.h"
23 #include "format/binary/ResourceTypeExtensions.h"
24 
25 namespace aapt {
26 
27 struct less_style_entries {
operator ()aapt::less_style_entries28   bool operator()(const Style::Entry* a, const Style::Entry* b) const {
29     if (a->key.id) {
30       if (b->key.id) {
31         return cmp_ids_dynamic_after_framework(a->key.id.value(), b->key.id.value());
32       }
33       return true;
34     }
35     if (!b->key.id) {
36       return a->key.name.value() < b->key.name.value();
37     }
38     return false;
39   }
40 };
41 
42 class MapFlattenVisitor : public ConstValueVisitor {
43  public:
44   using ConstValueVisitor::Visit;
45 
MapFlattenVisitor(ResTable_entry_ext * out_entry,BigBuffer * buffer)46   MapFlattenVisitor(ResTable_entry_ext* out_entry, BigBuffer* buffer)
47       : out_entry_(out_entry), buffer_(buffer) {
48   }
49 
Visit(const Attribute * attr)50   void Visit(const Attribute* attr) override {
51     {
52       Reference key = Reference(ResourceId(ResTable_map::ATTR_TYPE));
53       BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->type_mask);
54       FlattenEntry(&key, &val);
55     }
56 
57     if (attr->min_int != std::numeric_limits<int32_t>::min()) {
58       Reference key = Reference(ResourceId(ResTable_map::ATTR_MIN));
59       BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->min_int));
60       FlattenEntry(&key, &val);
61     }
62 
63     if (attr->max_int != std::numeric_limits<int32_t>::max()) {
64       Reference key = Reference(ResourceId(ResTable_map::ATTR_MAX));
65       BinaryPrimitive val(Res_value::TYPE_INT_DEC, static_cast<uint32_t>(attr->max_int));
66       FlattenEntry(&key, &val);
67     }
68 
69     for (const Attribute::Symbol& s : attr->symbols) {
70       BinaryPrimitive val(s.type, s.value);
71       FlattenEntry(&s.symbol, &val);
72     }
73   }
74 
Visit(const Style * style)75   void Visit(const Style* style) override {
76     if (style->parent) {
77       const Reference& parent_ref = style->parent.value();
78       CHECK(bool(parent_ref.id)) << "parent has no ID";
79       out_entry_->parent.ident = android::util::HostToDevice32(parent_ref.id.value().id);
80     }
81 
82     // Sort the style.
83     std::vector<const Style::Entry*> sorted_entries;
84     for (const auto& entry : style->entries) {
85       sorted_entries.emplace_back(&entry);
86     }
87 
88     std::sort(sorted_entries.begin(), sorted_entries.end(), less_style_entries());
89 
90     for (const Style::Entry* entry : sorted_entries) {
91       FlattenEntry(&entry->key, entry->value.get());
92     }
93   }
94 
Visit(const Styleable * styleable)95   void Visit(const Styleable* styleable) override {
96     for (auto& attr_ref : styleable->entries) {
97       BinaryPrimitive val(Res_value{});
98       FlattenEntry(&attr_ref, &val);
99     }
100   }
101 
Visit(const Array * array)102   void Visit(const Array* array) override {
103     const size_t count = array->elements.size();
104     for (size_t i = 0; i < count; i++) {
105       Reference key(android::ResTable_map::ATTR_MIN + i);
106       FlattenEntry(&key, array->elements[i].get());
107     }
108   }
109 
Visit(const Plural * plural)110   void Visit(const Plural* plural) override {
111     const size_t count = plural->values.size();
112     for (size_t i = 0; i < count; i++) {
113       if (!plural->values[i]) {
114         continue;
115       }
116 
117       ResourceId q;
118       switch (i) {
119         case Plural::Zero:
120           q.id = android::ResTable_map::ATTR_ZERO;
121           break;
122 
123         case Plural::One:
124           q.id = android::ResTable_map::ATTR_ONE;
125           break;
126 
127         case Plural::Two:
128           q.id = android::ResTable_map::ATTR_TWO;
129           break;
130 
131         case Plural::Few:
132           q.id = android::ResTable_map::ATTR_FEW;
133           break;
134 
135         case Plural::Many:
136           q.id = android::ResTable_map::ATTR_MANY;
137           break;
138 
139         case Plural::Other:
140           q.id = android::ResTable_map::ATTR_OTHER;
141           break;
142 
143         default:
144           LOG(FATAL) << "unhandled plural type";
145           break;
146       }
147 
148       Reference key(q);
149       FlattenEntry(&key, plural->values[i].get());
150     }
151   }
152 
153   /**
154    * Call this after visiting a Value. This will finish any work that
155    * needs to be done to prepare the entry.
156    */
Finish()157   void Finish() {
158     out_entry_->count = android::util::HostToDevice32(entry_count_);
159   }
160 
161  private:
162   DISALLOW_COPY_AND_ASSIGN(MapFlattenVisitor);
163 
FlattenKey(const Reference * key,ResTable_map * out_entry)164   void FlattenKey(const Reference* key, ResTable_map* out_entry) {
165     CHECK(bool(key->id)) << "key has no ID";
166     out_entry->name.ident = android::util::HostToDevice32(key->id.value().id);
167   }
168 
FlattenValue(const Item * value,ResTable_map * out_entry)169   void FlattenValue(const Item* value, ResTable_map* out_entry) {
170     CHECK(value->Flatten(&out_entry->value)) << "flatten failed";
171   }
172 
FlattenEntry(const Reference * key,Item * value)173   void FlattenEntry(const Reference* key, Item* value) {
174     ResTable_map* out_entry = buffer_->NextBlock<ResTable_map>();
175     FlattenKey(key, out_entry);
176     FlattenValue(value, out_entry);
177     out_entry->value.size = android::util::HostToDevice16(sizeof(out_entry->value));
178     entry_count_++;
179   }
180 
181   ResTable_entry_ext* out_entry_;
182   BigBuffer* buffer_;
183   size_t entry_count_ = 0;
184 };
185 
186 template <typename T>
WriteEntry(const FlatEntry * entry,T * out_result,bool compact=false)187 void WriteEntry(const FlatEntry* entry, T* out_result, bool compact = false) {
188   static_assert(std::is_same_v<ResTable_entry, T> || std::is_same_v<ResTable_entry_ext, T>,
189                 "T must be ResTable_entry or ResTable_entry_ext");
190 
191   ResTable_entry* out_entry = (ResTable_entry*)out_result;
192   uint16_t flags = 0;
193 
194   if (entry->entry->visibility.level == Visibility::Level::kPublic) {
195     flags |= ResTable_entry::FLAG_PUBLIC;
196   }
197 
198   if (entry->value->IsWeak()) {
199     flags |= ResTable_entry::FLAG_WEAK;
200   }
201 
202   if constexpr (std::is_same_v<ResTable_entry_ext, T>) {
203     flags |= ResTable_entry::FLAG_COMPLEX;
204   }
205 
206   if (!compact) {
207     out_entry->full.flags = android::util::HostToDevice16(flags);
208     out_entry->full.key.index = android::util::HostToDevice32(entry->entry_key);
209     out_entry->full.size = android::util::HostToDevice16(sizeof(T));
210   } else {
211     Res_value value;
212     CHECK(entry->entry_key < 0xffffu) << "cannot encode key in 16-bit";
213     CHECK(compact && (std::is_same_v<ResTable_entry, T>)) << "cannot encode complex entry";
214     CHECK(ValueCast<Item>(entry->value)->Flatten(&value)) << "flatten failed";
215 
216     flags |= ResTable_entry::FLAG_COMPACT | (value.dataType << 8);
217     out_entry->compact.flags = android::util::HostToDevice16(flags);
218     out_entry->compact.key = android::util::HostToDevice16(entry->entry_key);
219     out_entry->compact.data = value.data;
220   }
221 }
222 
WriteMapToBuffer(const FlatEntry * map_entry,BigBuffer * buffer)223 int32_t WriteMapToBuffer(const FlatEntry* map_entry, BigBuffer* buffer) {
224   int32_t offset = buffer->size();
225   ResTable_entry_ext* out_entry = buffer->NextBlock<ResTable_entry_ext>();
226   WriteEntry<ResTable_entry_ext>(map_entry, out_entry);
227 
228   MapFlattenVisitor visitor(out_entry, buffer);
229   map_entry->value->Accept(&visitor);
230   visitor.Finish();
231   return offset;
232 }
233 
234 template <bool compact_entry, typename T>
WriteItemToBuffer(const FlatEntry * item_entry,BigBuffer * buffer)235 std::pair<int32_t, T*> WriteItemToBuffer(const FlatEntry* item_entry, BigBuffer* buffer) {
236   int32_t offset = buffer->size();
237   T* out_entry = buffer->NextBlock<T>();
238 
239   if constexpr (compact_entry) {
240     WriteEntry(item_entry, out_entry, true);
241   } else {
242     WriteEntry(item_entry, &out_entry->entry);
243     CHECK(ValueCast<Item>(item_entry->value)->Flatten(&out_entry->value)) << "flatten failed";
244     out_entry->value.size = android::util::HostToDevice16(sizeof(out_entry->value));
245   }
246   return {offset, out_entry};
247 }
248 
249 // explicitly specialize both versions
250 template std::pair<int32_t, ResEntryValue<false>*> WriteItemToBuffer<false>(
251         const FlatEntry* item_entry, BigBuffer* buffer);
252 
253 template std::pair<int32_t, ResEntryValue<true>*> WriteItemToBuffer<true>(
254         const FlatEntry* item_entry, BigBuffer* buffer);
255 
256 }  // namespace aapt
257