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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 #include "flatten/TableFlattener.h"
18 
19 #include <algorithm>
20 #include <numeric>
21 #include <sstream>
22 #include <type_traits>
23 
24 #include "android-base/logging.h"
25 #include "android-base/macros.h"
26 
27 #include "ResourceTable.h"
28 #include "ResourceValues.h"
29 #include "SdkConstants.h"
30 #include "ValueVisitor.h"
31 #include "flatten/ChunkWriter.h"
32 #include "flatten/ResourceTypeExtensions.h"
33 #include "util/BigBuffer.h"
34 
35 using namespace android;
36 
37 namespace aapt {
38 
39 namespace {
40 
41 template <typename T>
cmp_ids(const T * a,const T * b)42 static bool cmp_ids(const T* a, const T* b) {
43   return a->id.value() < b->id.value();
44 }
45 
strcpy16_htod(uint16_t * dst,size_t len,const StringPiece16 & src)46 static void strcpy16_htod(uint16_t* dst, size_t len, const StringPiece16& src) {
47   if (len == 0) {
48     return;
49   }
50 
51   size_t i;
52   const char16_t* src_data = src.data();
53   for (i = 0; i < len - 1 && i < src.size(); i++) {
54     dst[i] = util::HostToDevice16((uint16_t)src_data[i]);
55   }
56   dst[i] = 0;
57 }
58 
cmp_style_entries(const Style::Entry & a,const Style::Entry & b)59 static bool cmp_style_entries(const Style::Entry& a, const Style::Entry& b) {
60   if (a.key.id) {
61     if (b.key.id) {
62       return a.key.id.value() < b.key.id.value();
63     }
64     return true;
65   } else if (!b.key.id) {
66     return a.key.name.value() < b.key.name.value();
67   }
68   return false;
69 }
70 
71 struct FlatEntry {
72   ResourceEntry* entry;
73   Value* value;
74 
75   // The entry string pool index to the entry's name.
76   uint32_t entry_key;
77 };
78 
79 class MapFlattenVisitor : public RawValueVisitor {
80  public:
81   using RawValueVisitor::Visit;
82 
MapFlattenVisitor(ResTable_entry_ext * out_entry,BigBuffer * buffer)83   MapFlattenVisitor(ResTable_entry_ext* out_entry, BigBuffer* buffer)
84       : out_entry_(out_entry), buffer_(buffer) {}
85 
Visit(Attribute * attr)86   void Visit(Attribute* attr) override {
87     {
88       Reference key = Reference(ResourceId(ResTable_map::ATTR_TYPE));
89       BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->type_mask);
90       FlattenEntry(&key, &val);
91     }
92 
93     if (attr->min_int != std::numeric_limits<int32_t>::min()) {
94       Reference key = Reference(ResourceId(ResTable_map::ATTR_MIN));
95       BinaryPrimitive val(Res_value::TYPE_INT_DEC,
96                           static_cast<uint32_t>(attr->min_int));
97       FlattenEntry(&key, &val);
98     }
99 
100     if (attr->max_int != std::numeric_limits<int32_t>::max()) {
101       Reference key = Reference(ResourceId(ResTable_map::ATTR_MAX));
102       BinaryPrimitive val(Res_value::TYPE_INT_DEC,
103                           static_cast<uint32_t>(attr->max_int));
104       FlattenEntry(&key, &val);
105     }
106 
107     for (Attribute::Symbol& s : attr->symbols) {
108       BinaryPrimitive val(Res_value::TYPE_INT_DEC, s.value);
109       FlattenEntry(&s.symbol, &val);
110     }
111   }
112 
Visit(Style * style)113   void Visit(Style* style) override {
114     if (style->parent) {
115       const Reference& parent_ref = style->parent.value();
116       CHECK(bool(parent_ref.id)) << "parent has no ID";
117       out_entry_->parent.ident = util::HostToDevice32(parent_ref.id.value().id);
118     }
119 
120     // Sort the style.
121     std::sort(style->entries.begin(), style->entries.end(), cmp_style_entries);
122 
123     for (Style::Entry& entry : style->entries) {
124       FlattenEntry(&entry.key, entry.value.get());
125     }
126   }
127 
Visit(Styleable * styleable)128   void Visit(Styleable* styleable) override {
129     for (auto& attr_ref : styleable->entries) {
130       BinaryPrimitive val(Res_value{});
131       FlattenEntry(&attr_ref, &val);
132     }
133   }
134 
Visit(Array * array)135   void Visit(Array* array) override {
136     for (auto& item : array->elements) {
137       ResTable_map* out_entry = buffer_->NextBlock<ResTable_map>();
138       FlattenValue(item.get(), out_entry);
139       out_entry->value.size = util::HostToDevice16(sizeof(out_entry->value));
140       entry_count_++;
141     }
142   }
143 
Visit(Plural * plural)144   void Visit(Plural* plural) override {
145     const size_t count = plural->values.size();
146     for (size_t i = 0; i < count; i++) {
147       if (!plural->values[i]) {
148         continue;
149       }
150 
151       ResourceId q;
152       switch (i) {
153         case Plural::Zero:
154           q.id = android::ResTable_map::ATTR_ZERO;
155           break;
156 
157         case Plural::One:
158           q.id = android::ResTable_map::ATTR_ONE;
159           break;
160 
161         case Plural::Two:
162           q.id = android::ResTable_map::ATTR_TWO;
163           break;
164 
165         case Plural::Few:
166           q.id = android::ResTable_map::ATTR_FEW;
167           break;
168 
169         case Plural::Many:
170           q.id = android::ResTable_map::ATTR_MANY;
171           break;
172 
173         case Plural::Other:
174           q.id = android::ResTable_map::ATTR_OTHER;
175           break;
176 
177         default:
178           LOG(FATAL) << "unhandled plural type";
179           break;
180       }
181 
182       Reference key(q);
183       FlattenEntry(&key, plural->values[i].get());
184     }
185   }
186 
187   /**
188    * Call this after visiting a Value. This will finish any work that
189    * needs to be done to prepare the entry.
190    */
Finish()191   void Finish() { out_entry_->count = util::HostToDevice32(entry_count_); }
192 
193  private:
194   DISALLOW_COPY_AND_ASSIGN(MapFlattenVisitor);
195 
FlattenKey(Reference * key,ResTable_map * out_entry)196   void FlattenKey(Reference* key, ResTable_map* out_entry) {
197     CHECK(bool(key->id)) << "key has no ID";
198     out_entry->name.ident = util::HostToDevice32(key->id.value().id);
199   }
200 
FlattenValue(Item * value,ResTable_map * out_entry)201   void FlattenValue(Item* value, ResTable_map* out_entry) {
202     CHECK(value->Flatten(&out_entry->value)) << "flatten failed";
203   }
204 
FlattenEntry(Reference * key,Item * value)205   void FlattenEntry(Reference* key, Item* value) {
206     ResTable_map* out_entry = buffer_->NextBlock<ResTable_map>();
207     FlattenKey(key, out_entry);
208     FlattenValue(value, out_entry);
209     out_entry->value.size = util::HostToDevice16(sizeof(out_entry->value));
210     entry_count_++;
211   }
212 
213   ResTable_entry_ext* out_entry_;
214   BigBuffer* buffer_;
215   size_t entry_count_ = 0;
216 };
217 
218 class PackageFlattener {
219  public:
PackageFlattener(IAaptContext * context,ResourceTablePackage * package,const std::map<size_t,std::string> * shared_libs,bool use_sparse_entries)220   PackageFlattener(IAaptContext* context, ResourceTablePackage* package,
221                    const std::map<size_t, std::string>* shared_libs, bool use_sparse_entries)
222       : context_(context),
223         diag_(context->GetDiagnostics()),
224         package_(package),
225         shared_libs_(shared_libs),
226         use_sparse_entries_(use_sparse_entries) {}
227 
FlattenPackage(BigBuffer * buffer)228   bool FlattenPackage(BigBuffer* buffer) {
229     ChunkWriter pkg_writer(buffer);
230     ResTable_package* pkg_header = pkg_writer.StartChunk<ResTable_package>(RES_TABLE_PACKAGE_TYPE);
231     pkg_header->id = util::HostToDevice32(package_->id.value());
232 
233     // AAPT truncated the package name, so do the same.
234     // Shared libraries require full package names, so don't truncate theirs.
235     if (context_->GetPackageType() != PackageType::kApp &&
236         package_->name.size() >= arraysize(pkg_header->name)) {
237       diag_->Error(DiagMessage() << "package name '" << package_->name
238                                  << "' is too long. "
239                                     "Shared libraries cannot have truncated package names");
240       return false;
241     }
242 
243     // Copy the package name in device endianness.
244     strcpy16_htod(pkg_header->name, arraysize(pkg_header->name), util::Utf8ToUtf16(package_->name));
245 
246     // Serialize the types. We do this now so that our type and key strings
247     // are populated. We write those first.
248     BigBuffer type_buffer(1024);
249     FlattenTypes(&type_buffer);
250 
251     pkg_header->typeStrings = util::HostToDevice32(pkg_writer.size());
252     StringPool::FlattenUtf16(pkg_writer.buffer(), type_pool_);
253 
254     pkg_header->keyStrings = util::HostToDevice32(pkg_writer.size());
255     StringPool::FlattenUtf8(pkg_writer.buffer(), key_pool_);
256 
257     // Append the types.
258     buffer->AppendBuffer(std::move(type_buffer));
259 
260     // If there are libraries (or if the package ID is 0x00), encode a library chunk.
261     if (package_->id.value() == 0x00 || !shared_libs_->empty()) {
262       FlattenLibrarySpec(buffer);
263     }
264 
265     pkg_writer.Finish();
266     return true;
267   }
268 
269  private:
270   DISALLOW_COPY_AND_ASSIGN(PackageFlattener);
271 
272   template <typename T, bool IsItem>
WriteEntry(FlatEntry * entry,BigBuffer * buffer)273   T* WriteEntry(FlatEntry* entry, BigBuffer* buffer) {
274     static_assert(std::is_same<ResTable_entry, T>::value ||
275                       std::is_same<ResTable_entry_ext, T>::value,
276                   "T must be ResTable_entry or ResTable_entry_ext");
277 
278     T* result = buffer->NextBlock<T>();
279     ResTable_entry* out_entry = (ResTable_entry*)result;
280     if (entry->entry->symbol_status.state == SymbolState::kPublic) {
281       out_entry->flags |= ResTable_entry::FLAG_PUBLIC;
282     }
283 
284     if (entry->value->IsWeak()) {
285       out_entry->flags |= ResTable_entry::FLAG_WEAK;
286     }
287 
288     if (!IsItem) {
289       out_entry->flags |= ResTable_entry::FLAG_COMPLEX;
290     }
291 
292     out_entry->flags = util::HostToDevice16(out_entry->flags);
293     out_entry->key.index = util::HostToDevice32(entry->entry_key);
294     out_entry->size = util::HostToDevice16(sizeof(T));
295     return result;
296   }
297 
FlattenValue(FlatEntry * entry,BigBuffer * buffer)298   bool FlattenValue(FlatEntry* entry, BigBuffer* buffer) {
299     if (Item* item = ValueCast<Item>(entry->value)) {
300       WriteEntry<ResTable_entry, true>(entry, buffer);
301       Res_value* outValue = buffer->NextBlock<Res_value>();
302       CHECK(item->Flatten(outValue)) << "flatten failed";
303       outValue->size = util::HostToDevice16(sizeof(*outValue));
304     } else {
305       ResTable_entry_ext* out_entry =
306           WriteEntry<ResTable_entry_ext, false>(entry, buffer);
307       MapFlattenVisitor visitor(out_entry, buffer);
308       entry->value->Accept(&visitor);
309       visitor.Finish();
310     }
311     return true;
312   }
313 
FlattenConfig(const ResourceTableType * type,const ConfigDescription & config,const size_t num_total_entries,std::vector<FlatEntry> * entries,BigBuffer * buffer)314   bool FlattenConfig(const ResourceTableType* type, const ConfigDescription& config,
315                      const size_t num_total_entries, std::vector<FlatEntry>* entries,
316                      BigBuffer* buffer) {
317     CHECK(num_total_entries != 0);
318     CHECK(num_total_entries <= std::numeric_limits<uint16_t>::max());
319 
320     ChunkWriter type_writer(buffer);
321     ResTable_type* type_header =
322         type_writer.StartChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
323     type_header->id = type->id.value();
324     type_header->config = config;
325     type_header->config.swapHtoD();
326 
327     std::vector<uint32_t> offsets;
328     offsets.resize(num_total_entries, 0xffffffffu);
329 
330     BigBuffer values_buffer(512);
331     for (FlatEntry& flat_entry : *entries) {
332       CHECK(static_cast<size_t>(flat_entry.entry->id.value()) < num_total_entries);
333       offsets[flat_entry.entry->id.value()] = values_buffer.size();
334       if (!FlattenValue(&flat_entry, &values_buffer)) {
335         diag_->Error(DiagMessage()
336                      << "failed to flatten resource '"
337                      << ResourceNameRef(package_->name, type->type, flat_entry.entry->name)
338                      << "' for configuration '" << config << "'");
339         return false;
340       }
341     }
342 
343     bool sparse_encode = use_sparse_entries_;
344 
345     // Only sparse encode if the entries will be read on platforms O+.
346     sparse_encode =
347         sparse_encode && (context_->GetMinSdkVersion() >= SDK_O || config.sdkVersion >= SDK_O);
348 
349     // Only sparse encode if the offsets are representable in 2 bytes.
350     sparse_encode =
351         sparse_encode && (values_buffer.size() / 4u) <= std::numeric_limits<uint16_t>::max();
352 
353     // Only sparse encode if the ratio of populated entries to total entries is below some
354     // threshold.
355     sparse_encode =
356         sparse_encode && ((100 * entries->size()) / num_total_entries) < kSparseEncodingThreshold;
357 
358     if (sparse_encode) {
359       type_header->entryCount = util::HostToDevice32(entries->size());
360       type_header->flags |= ResTable_type::FLAG_SPARSE;
361       ResTable_sparseTypeEntry* indices =
362           type_writer.NextBlock<ResTable_sparseTypeEntry>(entries->size());
363       for (size_t i = 0; i < num_total_entries; i++) {
364         if (offsets[i] != ResTable_type::NO_ENTRY) {
365           CHECK((offsets[i] & 0x03) == 0);
366           indices->idx = util::HostToDevice16(i);
367           indices->offset = util::HostToDevice16(offsets[i] / 4u);
368           indices++;
369         }
370       }
371     } else {
372       type_header->entryCount = util::HostToDevice32(num_total_entries);
373       uint32_t* indices = type_writer.NextBlock<uint32_t>(num_total_entries);
374       for (size_t i = 0; i < num_total_entries; i++) {
375         indices[i] = util::HostToDevice32(offsets[i]);
376       }
377     }
378 
379     type_header->entriesStart = util::HostToDevice32(type_writer.size());
380     type_writer.buffer()->AppendBuffer(std::move(values_buffer));
381     type_writer.Finish();
382     return true;
383   }
384 
CollectAndSortTypes()385   std::vector<ResourceTableType*> CollectAndSortTypes() {
386     std::vector<ResourceTableType*> sorted_types;
387     for (auto& type : package_->types) {
388       if (type->type == ResourceType::kStyleable) {
389         // Styleables aren't real Resource Types, they are represented in the
390         // R.java file.
391         continue;
392       }
393 
394       CHECK(bool(type->id)) << "type must have an ID set";
395 
396       sorted_types.push_back(type.get());
397     }
398     std::sort(sorted_types.begin(), sorted_types.end(),
399               cmp_ids<ResourceTableType>);
400     return sorted_types;
401   }
402 
CollectAndSortEntries(ResourceTableType * type)403   std::vector<ResourceEntry*> CollectAndSortEntries(ResourceTableType* type) {
404     // Sort the entries by entry ID.
405     std::vector<ResourceEntry*> sorted_entries;
406     for (auto& entry : type->entries) {
407       CHECK(bool(entry->id)) << "entry must have an ID set";
408       sorted_entries.push_back(entry.get());
409     }
410     std::sort(sorted_entries.begin(), sorted_entries.end(), cmp_ids<ResourceEntry>);
411     return sorted_entries;
412   }
413 
FlattenTypeSpec(ResourceTableType * type,std::vector<ResourceEntry * > * sorted_entries,BigBuffer * buffer)414   bool FlattenTypeSpec(ResourceTableType* type,
415                        std::vector<ResourceEntry*>* sorted_entries,
416                        BigBuffer* buffer) {
417     ChunkWriter type_spec_writer(buffer);
418     ResTable_typeSpec* spec_header =
419         type_spec_writer.StartChunk<ResTable_typeSpec>(
420             RES_TABLE_TYPE_SPEC_TYPE);
421     spec_header->id = type->id.value();
422 
423     if (sorted_entries->empty()) {
424       type_spec_writer.Finish();
425       return true;
426     }
427 
428     // We can't just take the size of the vector. There may be holes in the
429     // entry ID space.
430     // Since the entries are sorted by ID, the last one will be the biggest.
431     const size_t num_entries = sorted_entries->back()->id.value() + 1;
432 
433     spec_header->entryCount = util::HostToDevice32(num_entries);
434 
435     // Reserve space for the masks of each resource in this type. These
436     // show for which configuration axis the resource changes.
437     uint32_t* config_masks = type_spec_writer.NextBlock<uint32_t>(num_entries);
438 
439     const size_t actual_num_entries = sorted_entries->size();
440     for (size_t entryIndex = 0; entryIndex < actual_num_entries; entryIndex++) {
441       ResourceEntry* entry = sorted_entries->at(entryIndex);
442 
443       // Populate the config masks for this entry.
444 
445       if (entry->symbol_status.state == SymbolState::kPublic) {
446         config_masks[entry->id.value()] |=
447             util::HostToDevice32(ResTable_typeSpec::SPEC_PUBLIC);
448       }
449 
450       const size_t config_count = entry->values.size();
451       for (size_t i = 0; i < config_count; i++) {
452         const ConfigDescription& config = entry->values[i]->config;
453         for (size_t j = i + 1; j < config_count; j++) {
454           config_masks[entry->id.value()] |=
455               util::HostToDevice32(config.diff(entry->values[j]->config));
456         }
457       }
458     }
459     type_spec_writer.Finish();
460     return true;
461   }
462 
FlattenTypes(BigBuffer * buffer)463   bool FlattenTypes(BigBuffer* buffer) {
464     // Sort the types by their IDs. They will be inserted into the StringPool in
465     // this order.
466     std::vector<ResourceTableType*> sorted_types = CollectAndSortTypes();
467 
468     size_t expected_type_id = 1;
469     for (ResourceTableType* type : sorted_types) {
470       // If there is a gap in the type IDs, fill in the StringPool
471       // with empty values until we reach the ID we expect.
472       while (type->id.value() > expected_type_id) {
473         std::stringstream type_name;
474         type_name << "?" << expected_type_id;
475         type_pool_.MakeRef(type_name.str());
476         expected_type_id++;
477       }
478       expected_type_id++;
479       type_pool_.MakeRef(ToString(type->type));
480 
481       std::vector<ResourceEntry*> sorted_entries = CollectAndSortEntries(type);
482       if (sorted_entries.empty()) {
483         continue;
484       }
485 
486       if (!FlattenTypeSpec(type, &sorted_entries, buffer)) {
487         return false;
488       }
489 
490       // Since the entries are sorted by ID, the last ID will be the largest.
491       const size_t num_entries = sorted_entries.back()->id.value() + 1;
492 
493       // The binary resource table lists resource entries for each
494       // configuration.
495       // We store them inverted, where a resource entry lists the values for
496       // each
497       // configuration available. Here we reverse this to match the binary
498       // table.
499       std::map<ConfigDescription, std::vector<FlatEntry>> config_to_entry_list_map;
500       for (ResourceEntry* entry : sorted_entries) {
501         const uint32_t key_index = (uint32_t)key_pool_.MakeRef(entry->name).index();
502 
503         // Group values by configuration.
504         for (auto& config_value : entry->values) {
505           config_to_entry_list_map[config_value->config].push_back(
506               FlatEntry{entry, config_value->value.get(), key_index});
507         }
508       }
509 
510       // Flatten a configuration value.
511       for (auto& entry : config_to_entry_list_map) {
512         if (!FlattenConfig(type, entry.first, num_entries, &entry.second, buffer)) {
513           return false;
514         }
515       }
516     }
517     return true;
518   }
519 
FlattenLibrarySpec(BigBuffer * buffer)520   void FlattenLibrarySpec(BigBuffer* buffer) {
521     ChunkWriter lib_writer(buffer);
522     ResTable_lib_header* lib_header =
523         lib_writer.StartChunk<ResTable_lib_header>(RES_TABLE_LIBRARY_TYPE);
524 
525     const size_t num_entries = (package_->id.value() == 0x00 ? 1 : 0) + shared_libs_->size();
526     CHECK(num_entries > 0);
527 
528     lib_header->count = util::HostToDevice32(num_entries);
529 
530     ResTable_lib_entry* lib_entry = buffer->NextBlock<ResTable_lib_entry>(num_entries);
531     if (package_->id.value() == 0x00) {
532       // Add this package
533       lib_entry->packageId = util::HostToDevice32(0x00);
534       strcpy16_htod(lib_entry->packageName, arraysize(lib_entry->packageName),
535                     util::Utf8ToUtf16(package_->name));
536       ++lib_entry;
537     }
538 
539     for (auto& map_entry : *shared_libs_) {
540       lib_entry->packageId = util::HostToDevice32(map_entry.first);
541       strcpy16_htod(lib_entry->packageName, arraysize(lib_entry->packageName),
542                     util::Utf8ToUtf16(map_entry.second));
543       ++lib_entry;
544     }
545     lib_writer.Finish();
546   }
547 
548   IAaptContext* context_;
549   IDiagnostics* diag_;
550   ResourceTablePackage* package_;
551   const std::map<size_t, std::string>* shared_libs_;
552   bool use_sparse_entries_;
553   StringPool type_pool_;
554   StringPool key_pool_;
555 };
556 
557 }  // namespace
558 
Consume(IAaptContext * context,ResourceTable * table)559 bool TableFlattener::Consume(IAaptContext* context, ResourceTable* table) {
560   // We must do this before writing the resources, since the string pool IDs may change.
561   table->string_pool.Prune();
562   table->string_pool.Sort([](const StringPool::Context& a, const StringPool::Context& b) -> int {
563     int diff = util::compare(a.priority, b.priority);
564     if (diff == 0) {
565       diff = a.config.compare(b.config);
566     }
567     return diff;
568   });
569 
570   // Write the ResTable header.
571   ChunkWriter table_writer(buffer_);
572   ResTable_header* table_header = table_writer.StartChunk<ResTable_header>(RES_TABLE_TYPE);
573   table_header->packageCount = util::HostToDevice32(table->packages.size());
574 
575   // Write a self mapping entry for this package if the ID is non-standard (0x7f).
576   if (context->GetPackageType() == PackageType::kApp) {
577     const uint8_t package_id = context->GetPackageId();
578     if (package_id != kFrameworkPackageId && package_id != kAppPackageId) {
579       table->included_packages_[package_id] = context->GetCompilationPackage();
580     }
581   }
582 
583   // Flatten the values string pool.
584   StringPool::FlattenUtf8(table_writer.buffer(), table->string_pool);
585 
586   BigBuffer package_buffer(1024);
587 
588   // Flatten each package.
589   for (auto& package : table->packages) {
590     PackageFlattener flattener(context, package.get(), &table->included_packages_,
591                                options_.use_sparse_entries);
592     if (!flattener.FlattenPackage(&package_buffer)) {
593       return false;
594     }
595   }
596 
597   // Finally merge all the packages into the main buffer.
598   table_writer.buffer()->AppendBuffer(std::move(package_buffer));
599   table_writer.Finish();
600   return true;
601 }
602 
603 }  // namespace aapt
604