tools/aapt2/flatten/TableFlattener.cpp - SHIFTPHONES/android_frameworks_base - Gitiles

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 #include "ResourceTable.h"
 #include "ResourceValues.h"
 #include "ValueVisitor.h"

 #include "flatten/ChunkWriter.h"
 #include "flatten/ResourceTypeExtensions.h"
 #include "flatten/TableFlattener.h"
 #include "util/BigBuffer.h"

 #include <type_traits>
 #include <numeric>
 #include <utils/misc.h>

 using namespace android;

 namespace aapt {

 namespace {

 template <typename T>
 static bool cmpIds(const T* a, const T* b) {
     return a->id.value() < b->id.value();
 }

 static void strcpy16_htod(uint16_t* dst, size_t len, const StringPiece16& src) {
     if (len == 0) {
         return;
     }

     size_t i;
     const char16_t* srcData = src.data();
     for (i = 0; i < len - 1 && i < src.size(); i++) {
         dst[i] = util::hostToDevice16((uint16_t) srcData[i]);
     }
     dst[i] = 0;
 }

 struct FlatEntry {
     ResourceEntry* entry;
     Value* value;
     uint32_t entryKey;
     uint32_t sourcePathKey;
     uint32_t sourceLine;
 };

 struct SymbolWriter {
     struct Entry {
         StringPool::Ref name;
         size_t offset;
     };

     StringPool pool;
     std::vector<Entry> symbols;

     void addSymbol(const ResourceNameRef& name, size_t offset) {
         symbols.push_back(Entry{ pool.makeRef(name.package.toString() + u":" +
                                               toString(name.type).toString() + u"/" +
                                               name.entry.toString()), offset });
     }
 };

 struct MapFlattenVisitor : public RawValueVisitor {
     using RawValueVisitor::visit;

     SymbolWriter* mSymbols;
     FlatEntry* mEntry;
     BigBuffer* mBuffer;
     size_t mEntryCount = 0;
     Maybe<uint32_t> mParentIdent;
     Maybe<ResourceNameRef> mParentName;

     MapFlattenVisitor(SymbolWriter* symbols, FlatEntry* entry, BigBuffer* buffer) :
             mSymbols(symbols), mEntry(entry), mBuffer(buffer) {
     }

     void flattenKey(Reference* key, ResTable_map* outEntry) {
         if (!key->id) {
             assert(key->name && "reference must have a name");

             outEntry->name.ident = util::hostToDevice32(0);
             mSymbols->addSymbol(key->name.value(), (mBuffer->size() - sizeof(ResTable_map)) +
                                     offsetof(ResTable_map, name));
         } else {
             outEntry->name.ident = util::hostToDevice32(key->id.value().id);
         }
     }

     void flattenValue(Item* value, ResTable_map* outEntry) {
         if (Reference* ref = valueCast<Reference>(value)) {
             if (!ref->id) {
                 assert(ref->name && "reference must have a name");

                 mSymbols->addSymbol(ref->name.value(), (mBuffer->size() - sizeof(ResTable_map)) +
                                         offsetof(ResTable_map, value) + offsetof(Res_value, data));
             }
         }

         bool result = value->flatten(&outEntry->value);
         assert(result && "flatten failed");
     }

     void flattenEntry(Reference* key, Item* value) {
         ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
         flattenKey(key, outEntry);
         flattenValue(value, outEntry);
         outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
         mEntryCount++;
     }

     void visit(Attribute* attr) override {
         {
             Reference key(ResourceId{ ResTable_map::ATTR_TYPE });
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->typeMask);
             flattenEntry(&key, &val);
         }

         for (Attribute::Symbol& s : attr->symbols) {
             BinaryPrimitive val(Res_value::TYPE_INT_DEC, s.value);
             flattenEntry(&s.symbol, &val);
         }
     }

     static bool cmpStyleEntries(const Style::Entry& a, const Style::Entry& b) {
         if (a.key.id) {
             if (b.key.id) {
                 return a.key.id.value() < b.key.id.value();
             }
             return true;
         } else if (!b.key.id) {
             return a.key.name.value() < b.key.name.value();
         }
         return false;
     }

     void visit(Style* style) override {
         if (style->parent) {
             if (!style->parent.value().id) {
                 assert(style->parent.value().name && "reference must have a name");
                 mParentName = style->parent.value().name;
             } else {
                 mParentIdent = style->parent.value().id.value().id;
             }
         }

         // Sort the style.
         std::sort(style->entries.begin(), style->entries.end(), cmpStyleEntries);

         for (Style::Entry& entry : style->entries) {
             flattenEntry(&entry.key, entry.value.get());
         }
     }

     void visit(Styleable* styleable) override {
         for (auto& attrRef : styleable->entries) {
             BinaryPrimitive val(Res_value{});
             flattenEntry(&attrRef, &val);
         }
     }

     void visit(Array* array) override {
         for (auto& item : array->items) {
             ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
             flattenValue(item.get(), outEntry);
             outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
             mEntryCount++;
         }
     }

     void visit(Plural* plural) override {
         const size_t count = plural->values.size();
         for (size_t i = 0; i < count; i++) {
             if (!plural->values[i]) {
                 continue;
             }

             ResourceId q;
             switch (i) {
             case Plural::Zero:
                 q.id = android::ResTable_map::ATTR_ZERO;
                 break;

             case Plural::One:
                 q.id = android::ResTable_map::ATTR_ONE;
                 break;

             case Plural::Two:
                 q.id = android::ResTable_map::ATTR_TWO;
                 break;

             case Plural::Few:
                 q.id = android::ResTable_map::ATTR_FEW;
                 break;

             case Plural::Many:
                 q.id = android::ResTable_map::ATTR_MANY;
                 break;

             case Plural::Other:
                 q.id = android::ResTable_map::ATTR_OTHER;
                 break;

             default:
                 assert(false);
                 break;
             }

             Reference key(q);
             flattenEntry(&key, plural->values[i].get());
         }
     }
 };

 struct PackageFlattener {
     IDiagnostics* mDiag;
     TableFlattenerOptions mOptions;
     ResourceTable* mTable;
     ResourceTablePackage* mPackage;
     SymbolWriter mSymbols;
     StringPool mTypePool;
     StringPool mKeyPool;
     StringPool mSourcePool;

     template <typename T>
     T* writeEntry(FlatEntry* entry, BigBuffer* buffer) {
         static_assert(std::is_same<ResTable_entry, T>::value ||
                       std::is_same<ResTable_entry_ext, T>::value,
                       "T must be ResTable_entry or ResTable_entry_ext");

         T* result = buffer->nextBlock<T>();
         ResTable_entry* outEntry = (ResTable_entry*)(result);
         if (entry->entry->publicStatus.isPublic) {
             outEntry->flags |= ResTable_entry::FLAG_PUBLIC;
         }

         if (entry->value->isWeak()) {
             outEntry->flags |= ResTable_entry::FLAG_WEAK;
         }

         if (!entry->value->isItem()) {
             outEntry->flags |= ResTable_entry::FLAG_COMPLEX;
         }

         outEntry->key.index = util::hostToDevice32(entry->entryKey);
         outEntry->size = sizeof(T);

         if (mOptions.useExtendedChunks) {
             // Write the extra source block. This will be ignored by the Android runtime.
             ResTable_entry_source* sourceBlock = buffer->nextBlock<ResTable_entry_source>();
             sourceBlock->pathIndex = util::hostToDevice32(entry->sourcePathKey);
             sourceBlock->line = util::hostToDevice32(entry->sourceLine);
             outEntry->size += sizeof(*sourceBlock);
         }

         outEntry->flags = util::hostToDevice16(outEntry->flags);
         outEntry->size = util::hostToDevice16(outEntry->size);
         return result;
     }

     bool flattenValue(FlatEntry* entry, BigBuffer* buffer) {
         if (entry->value->isItem()) {
             writeEntry<ResTable_entry>(entry, buffer);
             if (Reference* ref = valueCast<Reference>(entry->value)) {
                 if (!ref->id) {
                     assert(ref->name && "reference must have at least a name");
                     mSymbols.addSymbol(ref->name.value(),
                                        buffer->size() + offsetof(Res_value, data));
                 }
             }
             Res_value* outValue = buffer->nextBlock<Res_value>();
             bool result = static_cast<Item*>(entry->value)->flatten(outValue);
             assert(result && "flatten failed");
             outValue->size = util::hostToDevice16(sizeof(*outValue));
         } else {
             const size_t beforeEntry = buffer->size();
             ResTable_entry_ext* outEntry = writeEntry<ResTable_entry_ext>(entry, buffer);
             MapFlattenVisitor visitor(&mSymbols, entry, buffer);
             entry->value->accept(&visitor);
             outEntry->count = util::hostToDevice32(visitor.mEntryCount);
             if (visitor.mParentName) {
                 mSymbols.addSymbol(visitor.mParentName.value(),
                                    beforeEntry + offsetof(ResTable_entry_ext, parent));
             } else if (visitor.mParentIdent) {
                 outEntry->parent.ident = util::hostToDevice32(visitor.mParentIdent.value());
             }
         }
         return true;
     }

     bool flattenConfig(const ResourceTableType* type, const ConfigDescription& config,
                        std::vector<FlatEntry>* entries, BigBuffer* buffer) {
         ChunkWriter typeWriter(buffer);
         ResTable_type* typeHeader = typeWriter.startChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
         typeHeader->id = type->id.value();
         typeHeader->config = config;
         typeHeader->config.swapHtoD();

         auto maxAccum = [](uint32_t max, const std::unique_ptr<ResourceEntry>& a) -> uint32_t {
             return std::max(max, (uint32_t) a->id.value());
         };

         // Find the largest entry ID. That is how many entries we will have.
         const uint32_t entryCount =
                 std::accumulate(type->entries.begin(), type->entries.end(), 0, maxAccum) + 1;

         typeHeader->entryCount = util::hostToDevice32(entryCount);
         uint32_t* indices = typeWriter.nextBlock<uint32_t>(entryCount);

         assert((size_t) entryCount <= std::numeric_limits<uint16_t>::max() + 1);
         memset(indices, 0xff, entryCount * sizeof(uint32_t));

         typeHeader->entriesStart = util::hostToDevice32(typeWriter.size());

         const size_t entryStart = typeWriter.getBuffer()->size();
         for (FlatEntry& flatEntry : *entries) {
             assert(flatEntry.entry->id.value() < entryCount);
             indices[flatEntry.entry->id.value()] = util::hostToDevice32(
                     typeWriter.getBuffer()->size() - entryStart);
             if (!flattenValue(&flatEntry, typeWriter.getBuffer())) {
                 mDiag->error(DiagMessage()
                              << "failed to flatten resource '"
                              << ResourceNameRef(mPackage->name, type->type, flatEntry.entry->name)
                              << "' for configuration '" << config << "'");
                 return false;
             }
         }
         typeWriter.finish();
         return true;
     }

     std::vector<ResourceTableType*> collectAndSortTypes() {
         std::vector<ResourceTableType*> sortedTypes;
         for (auto& type : mPackage->types) {
             if (type->type == ResourceType::kStyleable && !mOptions.useExtendedChunks) {
                 // Styleables aren't real Resource Types, they are represented in the R.java
                 // file.
                 continue;
             }

             assert(type->id && "type must have an ID set");

             sortedTypes.push_back(type.get());
         }
         std::sort(sortedTypes.begin(), sortedTypes.end(), cmpIds<ResourceTableType>);
         return sortedTypes;
     }

     std::vector<ResourceEntry*> collectAndSortEntries(ResourceTableType* type) {
         // Sort the entries by entry ID.
         std::vector<ResourceEntry*> sortedEntries;
         for (auto& entry : type->entries) {
             assert(entry->id && "entry must have an ID set");
             sortedEntries.push_back(entry.get());
         }
         std::sort(sortedEntries.begin(), sortedEntries.end(), cmpIds<ResourceEntry>);
         return sortedEntries;
     }

     bool flattenTypeSpec(ResourceTableType* type, std::vector<ResourceEntry*>* sortedEntries,
                          BigBuffer* buffer) {
         ChunkWriter typeSpecWriter(buffer);
         ResTable_typeSpec* specHeader = typeSpecWriter.startChunk<ResTable_typeSpec>(
                 RES_TABLE_TYPE_SPEC_TYPE);
         specHeader->id = type->id.value();

         if (sortedEntries->empty()) {
             typeSpecWriter.finish();
             return true;
         }

         // We can't just take the size of the vector. There may be holes in the entry ID space.
         // Since the entries are sorted by ID, the last one will be the biggest.
         const size_t numEntries = sortedEntries->back()->id.value() + 1;

         specHeader->entryCount = util::hostToDevice32(numEntries);

         // Reserve space for the masks of each resource in this type. These
         // show for which configuration axis the resource changes.
         uint32_t* configMasks = typeSpecWriter.nextBlock<uint32_t>(numEntries);

         const size_t actualNumEntries = sortedEntries->size();
         for (size_t entryIndex = 0; entryIndex < actualNumEntries; entryIndex++) {
             ResourceEntry* entry = sortedEntries->at(entryIndex);

             // Populate the config masks for this entry.

             if (entry->publicStatus.isPublic) {
                 configMasks[entry->id.value()] |=
                         util::hostToDevice32(ResTable_typeSpec::SPEC_PUBLIC);
             }

             const size_t configCount = entry->values.size();
             for (size_t i = 0; i < configCount; i++) {
                 const ConfigDescription& config = entry->values[i].config;
                 for (size_t j = i + 1; j < configCount; j++) {
                     configMasks[entry->id.value()] |= util::hostToDevice32(
                             config.diff(entry->values[j].config));
                 }
             }
         }
         typeSpecWriter.finish();
         return true;
     }

     bool flattenPublic(ResourceTableType* type, std::vector<ResourceEntry*>* sortedEntries,
                        BigBuffer* buffer) {
         ChunkWriter publicWriter(buffer);
         Public_header* publicHeader = publicWriter.startChunk<Public_header>(RES_TABLE_PUBLIC_TYPE);
         publicHeader->typeId = type->id.value();

         for (ResourceEntry* entry : *sortedEntries) {
             if (entry->publicStatus.isPublic) {
                 // Write the public status of this entry.
                 Public_entry* publicEntry = publicWriter.nextBlock<Public_entry>();
                 publicEntry->entryId = util::hostToDevice32(entry->id.value());
                 publicEntry->key.index = util::hostToDevice32(mKeyPool.makeRef(
                         entry->name).getIndex());
                 publicEntry->source.index = util::hostToDevice32(mSourcePool.makeRef(
                         util::utf8ToUtf16(entry->publicStatus.source.path)).getIndex());
                 if (entry->publicStatus.source.line) {
                     publicEntry->sourceLine = util::hostToDevice32(
                             entry->publicStatus.source.line.value());
                 }

                 // Don't hostToDevice until the last step.
                 publicHeader->count += 1;
             }
         }

         publicHeader->count = util::hostToDevice32(publicHeader->count);
         publicWriter.finish();
         return true;
     }

     bool flattenTypes(BigBuffer* buffer) {
         // Sort the types by their IDs. They will be inserted into the StringPool in this order.
         std::vector<ResourceTableType*> sortedTypes = collectAndSortTypes();

         size_t expectedTypeId = 1;
         for (ResourceTableType* type : sortedTypes) {
             // If there is a gap in the type IDs, fill in the StringPool
             // with empty values until we reach the ID we expect.
             while (type->id.value() > expectedTypeId) {
                 std::u16string typeName(u"?");
                 typeName += expectedTypeId;
                 mTypePool.makeRef(typeName);
                 expectedTypeId++;
             }
             expectedTypeId++;
             mTypePool.makeRef(toString(type->type));

             std::vector<ResourceEntry*> sortedEntries = collectAndSortEntries(type);

             if (!flattenTypeSpec(type, &sortedEntries, buffer)) {
                 return false;
             }

             if (mOptions.useExtendedChunks) {
                 if (!flattenPublic(type, &sortedEntries, buffer)) {
                     return false;
                 }
             }

             // The binary resource table lists resource entries for each configuration.
             // We store them inverted, where a resource entry lists the values for each
             // configuration available. Here we reverse this to match the binary table.
             std::map<ConfigDescription, std::vector<FlatEntry>> configToEntryListMap;
             for (ResourceEntry* entry : sortedEntries) {
                 const size_t keyIndex = mKeyPool.makeRef(entry->name).getIndex();

                 // Group values by configuration.
                 for (auto& configValue : entry->values) {
                    configToEntryListMap[configValue.config].push_back(FlatEntry{
                             entry, configValue.value.get(), (uint32_t) keyIndex,
                             (uint32_t)(mSourcePool.makeRef(util::utf8ToUtf16(
                                     configValue.source.path)).getIndex()),
                             (uint32_t)(configValue.source.line
                                     ? configValue.source.line.value() : 0)
                    });
                 }
             }

             // Flatten a configuration value.
             for (auto& entry : configToEntryListMap) {
                 if (!flattenConfig(type, entry.first, &entry.second, buffer)) {
                     return false;
                 }
             }
         }
         return true;
     }

     bool flattenPackage(BigBuffer* buffer) {
         // We must do this before writing the resources, since the string pool IDs may change.
         mTable->stringPool.sort([](const StringPool::Entry& a, const StringPool::Entry& b) -> bool {
             int diff = a.context.priority - b.context.priority;
             if (diff < 0) return true;
             if (diff > 0) return false;
             diff = a.context.config.compare(b.context.config);
             if (diff < 0) return true;
             if (diff > 0) return false;
             return a.value < b.value;
         });
         mTable->stringPool.prune();

         const size_t beginningIndex = buffer->size();

         BigBuffer typeBuffer(1024);
         if (!flattenTypes(&typeBuffer)) {
             return false;
         }

         ChunkWriter tableWriter(buffer);
         ResTable_header* tableHeader = tableWriter.startChunk<ResTable_header>(RES_TABLE_TYPE);
         tableHeader->packageCount = util::hostToDevice32(1);

         SymbolTable_entry* symbolEntryData = nullptr;
         if (mOptions.useExtendedChunks && !mSymbols.symbols.empty()) {
             // Sort the offsets so we can scan them linearly.
             std::sort(mSymbols.symbols.begin(), mSymbols.symbols.end(),
                       [](const SymbolWriter::Entry& a, const SymbolWriter::Entry& b) -> bool {
                           return a.offset < b.offset;
                       });

             ChunkWriter symbolWriter(tableWriter.getBuffer());
             SymbolTable_header* symbolHeader = symbolWriter.startChunk<SymbolTable_header>(
                     RES_TABLE_SYMBOL_TABLE_TYPE);
             symbolHeader->count = util::hostToDevice32(mSymbols.symbols.size());

             symbolEntryData = symbolWriter.nextBlock<SymbolTable_entry>(mSymbols.symbols.size());
             StringPool::flattenUtf8(symbolWriter.getBuffer(), mSymbols.pool);
             symbolWriter.finish();
         }

         if (mOptions.useExtendedChunks && mSourcePool.size() > 0) {
             // Write out source pool.
             ChunkWriter srcWriter(tableWriter.getBuffer());
             srcWriter.startChunk<ResChunk_header>(RES_TABLE_SOURCE_POOL_TYPE);
             StringPool::flattenUtf8(srcWriter.getBuffer(), mSourcePool);
             srcWriter.finish();
         }

         StringPool::flattenUtf8(tableWriter.getBuffer(), mTable->stringPool);

         ChunkWriter pkgWriter(tableWriter.getBuffer());
         ResTable_package* pkgHeader = pkgWriter.startChunk<ResTable_package>(
                 RES_TABLE_PACKAGE_TYPE);
         pkgHeader->id = util::hostToDevice32(mPackage->id.value());

         if (mPackage->name.size() >= NELEM(pkgHeader->name)) {
             mDiag->error(DiagMessage() <<
                          "package name '" << mPackage->name << "' is too long");
             return false;
         }

         strcpy16_htod(pkgHeader->name, NELEM(pkgHeader->name), mPackage->name);

         pkgHeader->typeStrings = util::hostToDevice32(pkgWriter.size());
         StringPool::flattenUtf16(pkgWriter.getBuffer(), mTypePool);

         pkgHeader->keyStrings = util::hostToDevice32(pkgWriter.size());
         StringPool::flattenUtf16(pkgWriter.getBuffer(), mKeyPool);

         // Actually write out the symbol entries if we have symbols.
         if (symbolEntryData) {
             for (auto& entry : mSymbols.symbols) {
                 symbolEntryData->stringIndex = util::hostToDevice32(entry.name.getIndex());

                 // The symbols were all calculated with the typeBuffer offset. We need to
                 // add the beginning of the output buffer.
                 symbolEntryData->offset = util::hostToDevice32(
                         (pkgWriter.getBuffer()->size() - beginningIndex) + entry.offset);

                 symbolEntryData++;
             }
         }

         // Write out the types and entries.
         pkgWriter.getBuffer()->appendBuffer(std::move(typeBuffer));

         pkgWriter.finish();
         tableWriter.finish();
         return true;
     }
 };

 } // namespace

 bool TableFlattener::consume(IAaptContext* context, ResourceTable* table) {
     for (auto& package : table->packages) {
         // Only support flattening one package. Since the StringPool is shared between packages
         // in ResourceTable, we must fail if other packages are present, since their strings
         // will be included in the final ResourceTable.
         if (context->getCompilationPackage() != package->name) {
             context->getDiagnostics()->error(DiagMessage()
                                              << "resources for package '" << package->name
                                              << "' can't be flattened when compiling package '"
                                              << context->getCompilationPackage() << "'");
             return false;
         }

         if (!package->id || package->id.value() != context->getPackageId()) {
             context->getDiagnostics()->error(DiagMessage()
                                              << "package '" << package->name << "' must have "
                                              << "package id "
                                              << std::hex << context->getPackageId() << std::dec);
             return false;
         }

         PackageFlattener flattener = {
                 context->getDiagnostics(),
                 mOptions,
                 table,
                 package.get()
         };

         if (!flattener.flattenPackage(mBuffer)) {
             return false;
         }
         return true;
     }

     context->getDiagnostics()->error(DiagMessage()
                                      << "compilation package '" << context->getCompilationPackage()
                                      << "' not found");
     return false;
 }

 } // namespace aapt
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	#include "ResourceTable.h"
	#include "ResourceValues.h"
	#include "ValueVisitor.h"

	#include "flatten/ChunkWriter.h"
	#include "flatten/ResourceTypeExtensions.h"
	#include "flatten/TableFlattener.h"
	#include "util/BigBuffer.h"

	#include <type_traits>
	#include <numeric>
	#include <utils/misc.h>

	using namespace android;

	namespace aapt {

	namespace {

	template <typename T>
	static bool cmpIds(const T* a, const T* b) {
	return a->id.value() < b->id.value();
	}

	static void strcpy16_htod(uint16_t* dst, size_t len, const StringPiece16& src) {
	if (len == 0) {
	return;
	}

	size_t i;
	const char16_t* srcData = src.data();
	for (i = 0; i < len - 1 && i < src.size(); i++) {
	dst[i] = util::hostToDevice16((uint16_t) srcData[i]);
	}
	dst[i] = 0;
	}

	struct FlatEntry {
	ResourceEntry* entry;
	Value* value;
	uint32_t entryKey;
	uint32_t sourcePathKey;
	uint32_t sourceLine;
	};

	struct SymbolWriter {
	struct Entry {
	StringPool::Ref name;
	size_t offset;
	};

	StringPool pool;
	std::vector<Entry> symbols;

	void addSymbol(const ResourceNameRef& name, size_t offset) {
	symbols.push_back(Entry{ pool.makeRef(name.package.toString() + u":" +
	toString(name.type).toString() + u"/" +
	name.entry.toString()), offset });
	}
	};

	struct MapFlattenVisitor : public RawValueVisitor {
	using RawValueVisitor::visit;

	SymbolWriter* mSymbols;
	FlatEntry* mEntry;
	BigBuffer* mBuffer;
	size_t mEntryCount = 0;
	Maybe<uint32_t> mParentIdent;
	Maybe<ResourceNameRef> mParentName;

	MapFlattenVisitor(SymbolWriter* symbols, FlatEntry* entry, BigBuffer* buffer) :
	mSymbols(symbols), mEntry(entry), mBuffer(buffer) {
	}

	void flattenKey(Reference* key, ResTable_map* outEntry) {
	if (!key->id) {
	assert(key->name && "reference must have a name");

	outEntry->name.ident = util::hostToDevice32(0);
	mSymbols->addSymbol(key->name.value(), (mBuffer->size() - sizeof(ResTable_map)) +
	offsetof(ResTable_map, name));
	} else {
	outEntry->name.ident = util::hostToDevice32(key->id.value().id);
	}
	}

	void flattenValue(Item* value, ResTable_map* outEntry) {
	if (Reference* ref = valueCast<Reference>(value)) {
	if (!ref->id) {
	assert(ref->name && "reference must have a name");

	mSymbols->addSymbol(ref->name.value(), (mBuffer->size() - sizeof(ResTable_map)) +
	offsetof(ResTable_map, value) + offsetof(Res_value, data));
	}
	}

	bool result = value->flatten(&outEntry->value);
	assert(result && "flatten failed");
	}

	void flattenEntry(Reference* key, Item* value) {
	ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
	flattenKey(key, outEntry);
	flattenValue(value, outEntry);
	outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
	mEntryCount++;
	}

	void visit(Attribute* attr) override {
	{
	Reference key(ResourceId{ ResTable_map::ATTR_TYPE });
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, attr->typeMask);
	flattenEntry(&key, &val);
	}

	for (Attribute::Symbol& s : attr->symbols) {
	BinaryPrimitive val(Res_value::TYPE_INT_DEC, s.value);
	flattenEntry(&s.symbol, &val);
	}
	}

	static bool cmpStyleEntries(const Style::Entry& a, const Style::Entry& b) {
	if (a.key.id) {
	if (b.key.id) {
	return a.key.id.value() < b.key.id.value();
	}
	return true;
	} else if (!b.key.id) {
	return a.key.name.value() < b.key.name.value();
	}
	return false;
	}

	void visit(Style* style) override {
	if (style->parent) {
	if (!style->parent.value().id) {
	assert(style->parent.value().name && "reference must have a name");
	mParentName = style->parent.value().name;
	} else {
	mParentIdent = style->parent.value().id.value().id;
	}
	}

	// Sort the style.
	std::sort(style->entries.begin(), style->entries.end(), cmpStyleEntries);

	for (Style::Entry& entry : style->entries) {
	flattenEntry(&entry.key, entry.value.get());
	}
	}

	void visit(Styleable* styleable) override {
	for (auto& attrRef : styleable->entries) {
	BinaryPrimitive val(Res_value{});
	flattenEntry(&attrRef, &val);
	}
	}

	void visit(Array* array) override {
	for (auto& item : array->items) {
	ResTable_map* outEntry = mBuffer->nextBlock<ResTable_map>();
	flattenValue(item.get(), outEntry);
	outEntry->value.size = util::hostToDevice16(sizeof(outEntry->value));
	mEntryCount++;
	}
	}

	void visit(Plural* plural) override {
	const size_t count = plural->values.size();
	for (size_t i = 0; i < count; i++) {
	if (!plural->values[i]) {
	continue;
	}

	ResourceId q;
	switch (i) {
	case Plural::Zero:
	q.id = android::ResTable_map::ATTR_ZERO;
	break;

	case Plural::One:
	q.id = android::ResTable_map::ATTR_ONE;
	break;

	case Plural::Two:
	q.id = android::ResTable_map::ATTR_TWO;
	break;

	case Plural::Few:
	q.id = android::ResTable_map::ATTR_FEW;
	break;

	case Plural::Many:
	q.id = android::ResTable_map::ATTR_MANY;
	break;

	case Plural::Other:
	q.id = android::ResTable_map::ATTR_OTHER;
	break;

	default:
	assert(false);
	break;
	}

	Reference key(q);
	flattenEntry(&key, plural->values[i].get());
	}
	}
	};

	struct PackageFlattener {
	IDiagnostics* mDiag;
	TableFlattenerOptions mOptions;
	ResourceTable* mTable;
	ResourceTablePackage* mPackage;
	SymbolWriter mSymbols;
	StringPool mTypePool;
	StringPool mKeyPool;
	StringPool mSourcePool;

	template <typename T>
	T* writeEntry(FlatEntry* entry, BigBuffer* buffer) {
	static_assert(std::is_same<ResTable_entry, T>::value \|\|
	std::is_same<ResTable_entry_ext, T>::value,
	"T must be ResTable_entry or ResTable_entry_ext");

	T* result = buffer->nextBlock<T>();
	ResTable_entry* outEntry = (ResTable_entry*)(result);
	if (entry->entry->publicStatus.isPublic) {
	outEntry->flags \|= ResTable_entry::FLAG_PUBLIC;
	}

	if (entry->value->isWeak()) {
	outEntry->flags \|= ResTable_entry::FLAG_WEAK;
	}

	if (!entry->value->isItem()) {
	outEntry->flags \|= ResTable_entry::FLAG_COMPLEX;
	}

	outEntry->key.index = util::hostToDevice32(entry->entryKey);
	outEntry->size = sizeof(T);

	if (mOptions.useExtendedChunks) {
	// Write the extra source block. This will be ignored by the Android runtime.
	ResTable_entry_source* sourceBlock = buffer->nextBlock<ResTable_entry_source>();
	sourceBlock->pathIndex = util::hostToDevice32(entry->sourcePathKey);
	sourceBlock->line = util::hostToDevice32(entry->sourceLine);
	outEntry->size += sizeof(*sourceBlock);
	}

	outEntry->flags = util::hostToDevice16(outEntry->flags);
	outEntry->size = util::hostToDevice16(outEntry->size);
	return result;
	}

	bool flattenValue(FlatEntry* entry, BigBuffer* buffer) {
	if (entry->value->isItem()) {
	writeEntry<ResTable_entry>(entry, buffer);
	if (Reference* ref = valueCast<Reference>(entry->value)) {
	if (!ref->id) {
	assert(ref->name && "reference must have at least a name");
	mSymbols.addSymbol(ref->name.value(),
	buffer->size() + offsetof(Res_value, data));
	}
	}
	Res_value* outValue = buffer->nextBlock<Res_value>();
	bool result = static_cast<Item*>(entry->value)->flatten(outValue);
	assert(result && "flatten failed");
	outValue->size = util::hostToDevice16(sizeof(*outValue));
	} else {
	const size_t beforeEntry = buffer->size();
	ResTable_entry_ext* outEntry = writeEntry<ResTable_entry_ext>(entry, buffer);
	MapFlattenVisitor visitor(&mSymbols, entry, buffer);
	entry->value->accept(&visitor);
	outEntry->count = util::hostToDevice32(visitor.mEntryCount);
	if (visitor.mParentName) {
	mSymbols.addSymbol(visitor.mParentName.value(),
	beforeEntry + offsetof(ResTable_entry_ext, parent));
	} else if (visitor.mParentIdent) {
	outEntry->parent.ident = util::hostToDevice32(visitor.mParentIdent.value());
	}
	}
	return true;
	}

	bool flattenConfig(const ResourceTableType* type, const ConfigDescription& config,
	std::vector<FlatEntry>* entries, BigBuffer* buffer) {
	ChunkWriter typeWriter(buffer);
	ResTable_type* typeHeader = typeWriter.startChunk<ResTable_type>(RES_TABLE_TYPE_TYPE);
	typeHeader->id = type->id.value();
	typeHeader->config = config;
	typeHeader->config.swapHtoD();

	auto maxAccum = [](uint32_t max, const std::unique_ptr<ResourceEntry>& a) -> uint32_t {
	return std::max(max, (uint32_t) a->id.value());
	};

	// Find the largest entry ID. That is how many entries we will have.
	const uint32_t entryCount =
	std::accumulate(type->entries.begin(), type->entries.end(), 0, maxAccum) + 1;

	typeHeader->entryCount = util::hostToDevice32(entryCount);
	uint32_t* indices = typeWriter.nextBlock<uint32_t>(entryCount);

	assert((size_t) entryCount <= std::numeric_limits<uint16_t>::max() + 1);
	memset(indices, 0xff, entryCount * sizeof(uint32_t));

	typeHeader->entriesStart = util::hostToDevice32(typeWriter.size());

	const size_t entryStart = typeWriter.getBuffer()->size();
	for (FlatEntry& flatEntry : *entries) {
	assert(flatEntry.entry->id.value() < entryCount);
	indices[flatEntry.entry->id.value()] = util::hostToDevice32(
	typeWriter.getBuffer()->size() - entryStart);
	if (!flattenValue(&flatEntry, typeWriter.getBuffer())) {
	mDiag->error(DiagMessage()
	<< "failed to flatten resource '"
	<< ResourceNameRef(mPackage->name, type->type, flatEntry.entry->name)
	<< "' for configuration '" << config << "'");
	return false;
	}
	}
	typeWriter.finish();
	return true;
	}

	std::vector<ResourceTableType*> collectAndSortTypes() {
	std::vector<ResourceTableType*> sortedTypes;
	for (auto& type : mPackage->types) {
	if (type->type == ResourceType::kStyleable && !mOptions.useExtendedChunks) {
	// Styleables aren't real Resource Types, they are represented in the R.java
	// file.
	continue;
	}

	assert(type->id && "type must have an ID set");

	sortedTypes.push_back(type.get());
	}
	std::sort(sortedTypes.begin(), sortedTypes.end(), cmpIds<ResourceTableType>);
	return sortedTypes;
	}

	std::vector<ResourceEntry> collectAndSortEntries(ResourceTableType type) {
	// Sort the entries by entry ID.
	std::vector<ResourceEntry*> sortedEntries;
	for (auto& entry : type->entries) {
	assert(entry->id && "entry must have an ID set");
	sortedEntries.push_back(entry.get());
	}
	std::sort(sortedEntries.begin(), sortedEntries.end(), cmpIds<ResourceEntry>);
	return sortedEntries;
	}

	bool flattenTypeSpec(ResourceTableType* type, std::vector<ResourceEntry> sortedEntries,
	BigBuffer* buffer) {
	ChunkWriter typeSpecWriter(buffer);
	ResTable_typeSpec* specHeader = typeSpecWriter.startChunk<ResTable_typeSpec>(
	RES_TABLE_TYPE_SPEC_TYPE);
	specHeader->id = type->id.value();

	if (sortedEntries->empty()) {
	typeSpecWriter.finish();
	return true;
	}

	// We can't just take the size of the vector. There may be holes in the entry ID space.
	// Since the entries are sorted by ID, the last one will be the biggest.
	const size_t numEntries = sortedEntries->back()->id.value() + 1;

	specHeader->entryCount = util::hostToDevice32(numEntries);

	// Reserve space for the masks of each resource in this type. These
	// show for which configuration axis the resource changes.
	uint32_t* configMasks = typeSpecWriter.nextBlock<uint32_t>(numEntries);

	const size_t actualNumEntries = sortedEntries->size();
	for (size_t entryIndex = 0; entryIndex < actualNumEntries; entryIndex++) {
	ResourceEntry* entry = sortedEntries->at(entryIndex);

	// Populate the config masks for this entry.

	if (entry->publicStatus.isPublic) {
	configMasks[entry->id.value()] \|=
	util::hostToDevice32(ResTable_typeSpec::SPEC_PUBLIC);
	}

	const size_t configCount = entry->values.size();
	for (size_t i = 0; i < configCount; i++) {
	const ConfigDescription& config = entry->values[i].config;
	for (size_t j = i + 1; j < configCount; j++) {
	configMasks[entry->id.value()] \|= util::hostToDevice32(
	config.diff(entry->values[j].config));
	}
	}
	}
	typeSpecWriter.finish();
	return true;
	}

	bool flattenPublic(ResourceTableType* type, std::vector<ResourceEntry> sortedEntries,
	BigBuffer* buffer) {
	ChunkWriter publicWriter(buffer);
	Public_header* publicHeader = publicWriter.startChunk<Public_header>(RES_TABLE_PUBLIC_TYPE);
	publicHeader->typeId = type->id.value();

	for (ResourceEntry* entry : *sortedEntries) {
	if (entry->publicStatus.isPublic) {
	// Write the public status of this entry.
	Public_entry* publicEntry = publicWriter.nextBlock<Public_entry>();
	publicEntry->entryId = util::hostToDevice32(entry->id.value());
	publicEntry->key.index = util::hostToDevice32(mKeyPool.makeRef(
	entry->name).getIndex());
	publicEntry->source.index = util::hostToDevice32(mSourcePool.makeRef(
	util::utf8ToUtf16(entry->publicStatus.source.path)).getIndex());
	if (entry->publicStatus.source.line) {
	publicEntry->sourceLine = util::hostToDevice32(
	entry->publicStatus.source.line.value());
	}

	// Don't hostToDevice until the last step.
	publicHeader->count += 1;
	}
	}

	publicHeader->count = util::hostToDevice32(publicHeader->count);
	publicWriter.finish();
	return true;
	}

	bool flattenTypes(BigBuffer* buffer) {
	// Sort the types by their IDs. They will be inserted into the StringPool in this order.
	std::vector<ResourceTableType*> sortedTypes = collectAndSortTypes();

	size_t expectedTypeId = 1;
	for (ResourceTableType* type : sortedTypes) {
	// If there is a gap in the type IDs, fill in the StringPool
	// with empty values until we reach the ID we expect.
	while (type->id.value() > expectedTypeId) {
	std::u16string typeName(u"?");
	typeName += expectedTypeId;
	mTypePool.makeRef(typeName);
	expectedTypeId++;
	}
	expectedTypeId++;
	mTypePool.makeRef(toString(type->type));

	std::vector<ResourceEntry*> sortedEntries = collectAndSortEntries(type);

	if (!flattenTypeSpec(type, &sortedEntries, buffer)) {
	return false;
	}

	if (mOptions.useExtendedChunks) {
	if (!flattenPublic(type, &sortedEntries, buffer)) {
	return false;
	}
	}

	// The binary resource table lists resource entries for each configuration.
	// We store them inverted, where a resource entry lists the values for each
	// configuration available. Here we reverse this to match the binary table.
	std::map<ConfigDescription, std::vector<FlatEntry>> configToEntryListMap;
	for (ResourceEntry* entry : sortedEntries) {
	const size_t keyIndex = mKeyPool.makeRef(entry->name).getIndex();

	// Group values by configuration.
	for (auto& configValue : entry->values) {
	configToEntryListMap[configValue.config].push_back(FlatEntry{
	entry, configValue.value.get(), (uint32_t) keyIndex,
	(uint32_t)(mSourcePool.makeRef(util::utf8ToUtf16(
	configValue.source.path)).getIndex()),
	(uint32_t)(configValue.source.line
	? configValue.source.line.value() : 0)
	});
	}
	}

	// Flatten a configuration value.
	for (auto& entry : configToEntryListMap) {
	if (!flattenConfig(type, entry.first, &entry.second, buffer)) {
	return false;
	}
	}
	}
	return true;
	}

	bool flattenPackage(BigBuffer* buffer) {
	// We must do this before writing the resources, since the string pool IDs may change.
	mTable->stringPool.sort([](const StringPool::Entry& a, const StringPool::Entry& b) -> bool {
	int diff = a.context.priority - b.context.priority;
	if (diff < 0) return true;
	if (diff > 0) return false;
	diff = a.context.config.compare(b.context.config);
	if (diff < 0) return true;
	if (diff > 0) return false;
	return a.value < b.value;
	});
	mTable->stringPool.prune();

	const size_t beginningIndex = buffer->size();

	BigBuffer typeBuffer(1024);
	if (!flattenTypes(&typeBuffer)) {
	return false;
	}

	ChunkWriter tableWriter(buffer);
	ResTable_header* tableHeader = tableWriter.startChunk<ResTable_header>(RES_TABLE_TYPE);
	tableHeader->packageCount = util::hostToDevice32(1);

	SymbolTable_entry* symbolEntryData = nullptr;
	if (mOptions.useExtendedChunks && !mSymbols.symbols.empty()) {
	// Sort the offsets so we can scan them linearly.
	std::sort(mSymbols.symbols.begin(), mSymbols.symbols.end(),
	[](const SymbolWriter::Entry& a, const SymbolWriter::Entry& b) -> bool {
	return a.offset < b.offset;
	});

	ChunkWriter symbolWriter(tableWriter.getBuffer());
	SymbolTable_header* symbolHeader = symbolWriter.startChunk<SymbolTable_header>(
	RES_TABLE_SYMBOL_TABLE_TYPE);
	symbolHeader->count = util::hostToDevice32(mSymbols.symbols.size());

	symbolEntryData = symbolWriter.nextBlock<SymbolTable_entry>(mSymbols.symbols.size());
	StringPool::flattenUtf8(symbolWriter.getBuffer(), mSymbols.pool);
	symbolWriter.finish();
	}

	if (mOptions.useExtendedChunks && mSourcePool.size() > 0) {
	// Write out source pool.
	ChunkWriter srcWriter(tableWriter.getBuffer());
	srcWriter.startChunk<ResChunk_header>(RES_TABLE_SOURCE_POOL_TYPE);
	StringPool::flattenUtf8(srcWriter.getBuffer(), mSourcePool);
	srcWriter.finish();
	}

	StringPool::flattenUtf8(tableWriter.getBuffer(), mTable->stringPool);

	ChunkWriter pkgWriter(tableWriter.getBuffer());
	ResTable_package* pkgHeader = pkgWriter.startChunk<ResTable_package>(
	RES_TABLE_PACKAGE_TYPE);
	pkgHeader->id = util::hostToDevice32(mPackage->id.value());

	if (mPackage->name.size() >= NELEM(pkgHeader->name)) {
	mDiag->error(DiagMessage() <<
	"package name '" << mPackage->name << "' is too long");
	return false;
	}

	strcpy16_htod(pkgHeader->name, NELEM(pkgHeader->name), mPackage->name);

	pkgHeader->typeStrings = util::hostToDevice32(pkgWriter.size());
	StringPool::flattenUtf16(pkgWriter.getBuffer(), mTypePool);

	pkgHeader->keyStrings = util::hostToDevice32(pkgWriter.size());
	StringPool::flattenUtf16(pkgWriter.getBuffer(), mKeyPool);

	// Actually write out the symbol entries if we have symbols.
	if (symbolEntryData) {
	for (auto& entry : mSymbols.symbols) {
	symbolEntryData->stringIndex = util::hostToDevice32(entry.name.getIndex());

	// The symbols were all calculated with the typeBuffer offset. We need to
	// add the beginning of the output buffer.
	symbolEntryData->offset = util::hostToDevice32(
	(pkgWriter.getBuffer()->size() - beginningIndex) + entry.offset);

	symbolEntryData++;
	}
	}

	// Write out the types and entries.
	pkgWriter.getBuffer()->appendBuffer(std::move(typeBuffer));

	pkgWriter.finish();
	tableWriter.finish();
	return true;
	}
	};

	} // namespace

	bool TableFlattener::consume(IAaptContext* context, ResourceTable* table) {
	for (auto& package : table->packages) {
	// Only support flattening one package. Since the StringPool is shared between packages
	// in ResourceTable, we must fail if other packages are present, since their strings
	// will be included in the final ResourceTable.
	if (context->getCompilationPackage() != package->name) {
	context->getDiagnostics()->error(DiagMessage()
	<< "resources for package '" << package->name
	<< "' can't be flattened when compiling package '"
	<< context->getCompilationPackage() << "'");
	return false;
	}

	if (!package->id \|\| package->id.value() != context->getPackageId()) {
	context->getDiagnostics()->error(DiagMessage()
	<< "package '" << package->name << "' must have "
	<< "package id "
	<< std::hex << context->getPackageId() << std::dec);
	return false;
	}

	PackageFlattener flattener = {
	context->getDiagnostics(),
	mOptions,
	table,
	package.get()
	};

	if (!flattener.flattenPackage(mBuffer)) {
	return false;
	}
	return true;
	}

	context->getDiagnostics()->error(DiagMessage()
	<< "compilation package '" << context->getCompilationPackage()
	<< "' not found");
	return false;
	}

	} // namespace aapt