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/*
* 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 "process/SymbolTable.h"
#include <iostream>
#include "android-base/logging.h"
#include "android-base/stringprintf.h"
#include "androidfw/AssetManager.h"
#include "androidfw/ResourceTypes.h"
#include "ConfigDescription.h"
#include "NameMangler.h"
#include "Resource.h"
#include "ResourceUtils.h"
#include "ValueVisitor.h"
#include "util/Util.h"
using ::android::StringPiece;
using ::android::StringPiece16;
namespace aapt {
SymbolTable::SymbolTable(NameMangler* mangler)
: mangler_(mangler),
delegate_(util::make_unique<DefaultSymbolTableDelegate>()),
cache_(200),
id_cache_(200) {
}
void SymbolTable::SetDelegate(std::unique_ptr<ISymbolTableDelegate> delegate) {
CHECK(delegate != nullptr) << "can't set a nullptr delegate";
delegate_ = std::move(delegate);
// Clear the cache in case this delegate changes the order of lookup.
cache_.clear();
}
void SymbolTable::AppendSource(std::unique_ptr<ISymbolSource> source) {
sources_.push_back(std::move(source));
// We do not clear the cache, because sources earlier in the list take
// precedent.
}
void SymbolTable::PrependSource(std::unique_ptr<ISymbolSource> source) {
sources_.insert(sources_.begin(), std::move(source));
// We must clear the cache in case we did a lookup before adding this
// resource.
cache_.clear();
}
const SymbolTable::Symbol* SymbolTable::FindByName(const ResourceName& name) {
const ResourceName* name_with_package = &name;
// Fill in the package name if necessary.
// If there is no package in `name`, we will need to copy the ResourceName
// and store it somewhere; we use the Maybe<> class to reserve storage.
Maybe<ResourceName> name_with_package_impl;
if (name.package.empty()) {
name_with_package_impl = ResourceName(mangler_->GetTargetPackageName(), name.type, name.entry);
name_with_package = &name_with_package_impl.value();
}
// We store the name unmangled in the cache, so look it up as-is.
if (const std::shared_ptr<Symbol>& s = cache_.get(*name_with_package)) {
return s.get();
}
// The name was not found in the cache. Mangle it (if necessary) and find it in our sources.
// Again, here we use a Maybe<> object to reserve storage if we need to mangle.
const ResourceName* mangled_name = name_with_package;
Maybe<ResourceName> mangled_name_impl;
if (mangler_->ShouldMangle(name_with_package->package)) {
mangled_name_impl = mangler_->MangleName(*name_with_package);
mangled_name = &mangled_name_impl.value();
}
std::unique_ptr<Symbol> symbol = delegate_->FindByName(*mangled_name, sources_);
if (symbol == nullptr) {
return nullptr;
}
// Take ownership of the symbol into a shared_ptr. We do this because
// LruCache doesn't support unique_ptr.
std::shared_ptr<Symbol> shared_symbol(std::move(symbol));
// Since we look in the cache with the unmangled, but package prefixed
// name, we must put the same name into the cache.
cache_.put(*name_with_package, shared_symbol);
if (shared_symbol->id) {
// The symbol has an ID, so we can also cache this!
id_cache_.put(shared_symbol->id.value(), shared_symbol);
}
// Returns the raw pointer. Callers are not expected to hold on to this
// between calls to Find*.
return shared_symbol.get();
}
const SymbolTable::Symbol* SymbolTable::FindById(const ResourceId& id) {
if (const std::shared_ptr<Symbol>& s = id_cache_.get(id)) {
return s.get();
}
// We did not find it in the cache, so look through the sources.
std::unique_ptr<Symbol> symbol = delegate_->FindById(id, sources_);
if (symbol == nullptr) {
return nullptr;
}
// Take ownership of the symbol into a shared_ptr. We do this because LruCache
// doesn't support unique_ptr.
std::shared_ptr<Symbol> shared_symbol(std::move(symbol));
id_cache_.put(id, shared_symbol);
// Returns the raw pointer. Callers are not expected to hold on to this
// between calls to Find*.
return shared_symbol.get();
}
const SymbolTable::Symbol* SymbolTable::FindByReference(const Reference& ref) {
// First try the ID. This is because when we lookup by ID, we only fill in the ID cache.
// Looking up by name fills in the name and ID cache. So a cache miss will cause a failed
// ID lookup, then a successful name lookup. Subsequent look ups will hit immediately
// because the ID is cached too.
//
// If we looked up by name first, a cache miss would mean we failed to lookup by name, then
// succeeded to lookup by ID. Subsequent lookups will miss then hit.
const SymbolTable::Symbol* symbol = nullptr;
if (ref.id) {
symbol = FindById(ref.id.value());
}
if (ref.name && !symbol) {
symbol = FindByName(ref.name.value());
}
return symbol;
}
std::unique_ptr<SymbolTable::Symbol> DefaultSymbolTableDelegate::FindByName(
const ResourceName& name, const std::vector<std::unique_ptr<ISymbolSource>>& sources) {
for (auto& source : sources) {
std::unique_ptr<SymbolTable::Symbol> symbol = source->FindByName(name);
if (symbol) {
return symbol;
}
}
return {};
}
std::unique_ptr<SymbolTable::Symbol> DefaultSymbolTableDelegate::FindById(
ResourceId id, const std::vector<std::unique_ptr<ISymbolSource>>& sources) {
for (auto& source : sources) {
std::unique_ptr<SymbolTable::Symbol> symbol = source->FindById(id);
if (symbol) {
return symbol;
}
}
return {};
}
std::unique_ptr<SymbolTable::Symbol> ResourceTableSymbolSource::FindByName(
const ResourceName& name) {
Maybe<ResourceTable::SearchResult> result = table_->FindResource(name);
if (!result) {
if (name.type == ResourceType::kAttr) {
// Recurse and try looking up a private attribute.
return FindByName(ResourceName(name.package, ResourceType::kAttrPrivate, name.entry));
}
return {};
}
ResourceTable::SearchResult sr = result.value();
std::unique_ptr<SymbolTable::Symbol> symbol = util::make_unique<SymbolTable::Symbol>();
symbol->is_public = (sr.entry->visibility.level == Visibility::Level::kPublic);
if (sr.package->id && sr.type->id && sr.entry->id) {
symbol->id = ResourceId(sr.package->id.value(), sr.type->id.value(), sr.entry->id.value());
}
if (name.type == ResourceType::kAttr || name.type == ResourceType::kAttrPrivate) {
const ConfigDescription kDefaultConfig;
ResourceConfigValue* config_value = sr.entry->FindValue(kDefaultConfig);
if (config_value) {
// This resource has an Attribute.
if (Attribute* attr = ValueCast<Attribute>(config_value->value.get())) {
symbol->attribute = std::make_shared<Attribute>(*attr);
} else {
return {};
}
}
}
return symbol;
}
bool AssetManagerSymbolSource::AddAssetPath(const StringPiece& path) {
int32_t cookie = 0;
return assets_.addAssetPath(android::String8(path.data(), path.size()), &cookie);
}
std::map<size_t, std::string> AssetManagerSymbolSource::GetAssignedPackageIds() const {
std::map<size_t, std::string> package_map;
const android::ResTable& table = assets_.getResources(false);
const size_t package_count = table.getBasePackageCount();
for (size_t i = 0; i < package_count; i++) {
package_map[table.getBasePackageId(i)] =
util::Utf16ToUtf8(android::StringPiece16(table.getBasePackageName(i).string()));
}
return package_map;
}
static std::unique_ptr<SymbolTable::Symbol> LookupAttributeInTable(
const android::ResTable& table, ResourceId id) {
// Try as a bag.
const android::ResTable::bag_entry* entry;
ssize_t count = table.lockBag(id.id, &entry);
if (count < 0) {
table.unlockBag(entry);
return nullptr;
}
// We found a resource.
std::unique_ptr<SymbolTable::Symbol> s = util::make_unique<SymbolTable::Symbol>(id);
// Check to see if it is an attribute.
for (size_t i = 0; i < (size_t)count; i++) {
if (entry[i].map.name.ident == android::ResTable_map::ATTR_TYPE) {
s->attribute = std::make_shared<Attribute>(entry[i].map.value.data);
break;
}
}
if (s->attribute) {
for (size_t i = 0; i < (size_t)count; i++) {
const android::ResTable_map& map_entry = entry[i].map;
if (Res_INTERNALID(map_entry.name.ident)) {
switch (map_entry.name.ident) {
case android::ResTable_map::ATTR_MIN:
s->attribute->min_int = static_cast<int32_t>(map_entry.value.data);
break;
case android::ResTable_map::ATTR_MAX:
s->attribute->max_int = static_cast<int32_t>(map_entry.value.data);
break;
}
continue;
}
android::ResTable::resource_name entry_name;
if (!table.getResourceName(map_entry.name.ident, false, &entry_name)) {
table.unlockBag(entry);
return nullptr;
}
Maybe<ResourceName> parsed_name = ResourceUtils::ToResourceName(entry_name);
if (!parsed_name) {
return nullptr;
}
Attribute::Symbol symbol;
symbol.symbol.name = parsed_name.value();
symbol.symbol.id = ResourceId(map_entry.name.ident);
symbol.value = map_entry.value.data;
s->attribute->symbols.push_back(std::move(symbol));
}
}
table.unlockBag(entry);
return s;
}
std::unique_ptr<SymbolTable::Symbol> AssetManagerSymbolSource::FindByName(
const ResourceName& name) {
const android::ResTable& table = assets_.getResources(false);
const std::u16string package16 = util::Utf8ToUtf16(name.package);
const std::u16string type16 = util::Utf8ToUtf16(to_string(name.type));
const std::u16string entry16 = util::Utf8ToUtf16(name.entry);
const std::u16string mangled_entry16 =
util::Utf8ToUtf16(NameMangler::MangleEntry(name.package, name.entry));
uint32_t type_spec_flags;
ResourceId res_id;
// There can be mangled resources embedded within other packages. Here we will
// look into each package and look-up the mangled name until we find the resource.
const size_t count = table.getBasePackageCount();
for (size_t i = 0; i < count; i++) {
const android::String16 package_name = table.getBasePackageName(i);
StringPiece16 real_package16 = package16;
StringPiece16 real_entry16 = entry16;
std::u16string scratch_entry16;
if (StringPiece16(package_name) != package16) {
real_entry16 = mangled_entry16;
real_package16 = package_name.string();
}
type_spec_flags = 0;
res_id = table.identifierForName(real_entry16.data(), real_entry16.size(), type16.data(),
type16.size(), real_package16.data(), real_package16.size(),
&type_spec_flags);
if (res_id.is_valid()) {
break;
}
}
if (!res_id.is_valid()) {
return {};
}
std::unique_ptr<SymbolTable::Symbol> s;
if (name.type == ResourceType::kAttr) {
s = LookupAttributeInTable(table, res_id);
} else {
s = util::make_unique<SymbolTable::Symbol>();
s->id = res_id;
}
if (s) {
s->is_public = (type_spec_flags & android::ResTable_typeSpec::SPEC_PUBLIC) != 0;
return s;
}
return {};
}
static Maybe<ResourceName> GetResourceName(const android::ResTable& table,
ResourceId id) {
android::ResTable::resource_name res_name = {};
if (!table.getResourceName(id.id, true, &res_name)) {
return {};
}
return ResourceUtils::ToResourceName(res_name);
}
std::unique_ptr<SymbolTable::Symbol> AssetManagerSymbolSource::FindById(
ResourceId id) {
if (!id.is_valid()) {
// Exit early and avoid the error logs from AssetManager.
return {};
}
const android::ResTable& table = assets_.getResources(false);
Maybe<ResourceName> maybe_name = GetResourceName(table, id);
if (!maybe_name) {
return {};
}
uint32_t type_spec_flags = 0;
table.getResourceFlags(id.id, &type_spec_flags);
std::unique_ptr<SymbolTable::Symbol> s;
if (maybe_name.value().type == ResourceType::kAttr) {
s = LookupAttributeInTable(table, id);
} else {
s = util::make_unique<SymbolTable::Symbol>();
s->id = id;
}
if (s) {
s->is_public = (type_spec_flags & android::ResTable_typeSpec::SPEC_PUBLIC) != 0;
return s;
}
return {};
}
std::unique_ptr<SymbolTable::Symbol> AssetManagerSymbolSource::FindByReference(
const Reference& ref) {
// AssetManager always prefers IDs.
if (ref.id) {
return FindById(ref.id.value());
} else if (ref.name) {
return FindByName(ref.name.value());
}
return {};
}
} // namespace aapt