AAPT2: Separate out the various steps

An early refactor. Some ideas became clearer as
development continued. Now the various phases are much
clearer and more easily reusable.

Also added a ton of tests!

Change-Id: Ic8f0a70c8222370352e63533b329c40457c0903e
diff --git a/tools/aapt2/process/SymbolTable.cpp b/tools/aapt2/process/SymbolTable.cpp
new file mode 100644
index 0000000..c96b080
--- /dev/null
+++ b/tools/aapt2/process/SymbolTable.cpp
@@ -0,0 +1,204 @@
+/*
+ * 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 "ConfigDescription.h"
+#include "Resource.h"
+#include "util/Util.h"
+
+#include "process/SymbolTable.h"
+
+#include <androidfw/AssetManager.h>
+#include <androidfw/ResourceTypes.h>
+
+namespace aapt {
+
+const ISymbolTable::Symbol* SymbolTableWrapper::findByName(const ResourceName& name) {
+    if (const std::shared_ptr<Symbol>& s = mCache.get(name)) {
+        return s.get();
+    }
+
+    Maybe<ResourceTable::SearchResult> result = mTable->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();
+
+    // If no ID exists, we treat the symbol as missing. SymbolTables are used to
+    // find symbols to link.
+    if (!sr.package->id || !sr.type->id || !sr.entry->id) {
+        return {};
+    }
+
+    std::shared_ptr<Symbol> symbol = std::make_shared<Symbol>();
+    symbol->id = ResourceId{
+            sr.package->id.value(), sr.type->id.value(), sr.entry->id.value() };
+
+    if (name.type == ResourceType::kAttr || name.type == ResourceType::kAttrPrivate) {
+        auto lt = [](ResourceConfigValue& lhs, const ConfigDescription& rhs) -> bool {
+            return lhs.config < rhs;
+        };
+
+        const ConfigDescription kDefaultConfig;
+        auto iter = std::lower_bound(sr.entry->values.begin(), sr.entry->values.end(),
+                                     kDefaultConfig, lt);
+
+        if (iter != sr.entry->values.end() && iter->config == kDefaultConfig) {
+            // This resource has an Attribute.
+            symbol->attribute = util::make_unique<Attribute>(
+                    *static_cast<Attribute*>(iter->value.get()));
+        }
+    }
+
+    if (name.type == ResourceType::kAttrPrivate) {
+        // Masquerade this entry as kAttr.
+        mCache.put(ResourceName{ name.package, ResourceType::kAttr, name.entry }, symbol);
+    } else {
+        mCache.put(name, symbol);
+    }
+    return symbol.get();
+}
+
+
+static std::shared_ptr<ISymbolTable::Symbol> lookupIdInTable(const android::ResTable& table,
+                                                             ResourceId id) {
+    android::Res_value val = {};
+    ssize_t block = table.getResource(id.id, &val, true);
+    if (block >= 0) {
+        std::shared_ptr<ISymbolTable::Symbol> s = std::make_shared<ISymbolTable::Symbol>();
+        s->id = id;
+        return s;
+    }
+
+    // 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::shared_ptr<ISymbolTable::Symbol> s = std::make_shared<ISymbolTable::Symbol>();
+    s->id = 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 = util::make_unique<Attribute>(false);
+            s->attribute->typeMask = entry[i].map.value.data;
+            break;
+        }
+    }
+
+    if (s->attribute) {
+        for (size_t i = 0; i < (size_t) count; i++) {
+            if (!Res_INTERNALID(entry[i].map.name.ident)) {
+                android::ResTable::resource_name entryName;
+                if (!table.getResourceName(entry[i].map.name.ident, false, &entryName)) {
+                    table.unlockBag(entry);
+                    return nullptr;
+                }
+
+                const ResourceType* parsedType = parseResourceType(
+                        StringPiece16(entryName.type, entryName.typeLen));
+                if (!parsedType) {
+                    table.unlockBag(entry);
+                    return nullptr;
+                }
+
+                Attribute::Symbol symbol;
+                symbol.symbol.name = ResourceNameRef(
+                        StringPiece16(entryName.package, entryName.packageLen),
+                        *parsedType,
+                        StringPiece16(entryName.name, entryName.nameLen)).toResourceName();
+                symbol.symbol.id = ResourceId(entry[i].map.name.ident);
+                symbol.value = entry[i].map.value.data;
+                s->attribute->symbols.push_back(std::move(symbol));
+            }
+        }
+    }
+    table.unlockBag(entry);
+    return s;
+}
+
+const ISymbolTable::Symbol* AssetManagerSymbolTableBuilder::AssetManagerSymbolTable::findByName(
+        const ResourceName& name) {
+    if (const std::shared_ptr<Symbol>& s = mCache.get(name)) {
+        return s.get();
+    }
+
+    for (const auto& asset : mAssets) {
+        const android::ResTable& table = asset->getResources(false);
+        StringPiece16 typeStr = toString(name.type);
+        ResourceId resId = table.identifierForName(name.entry.data(), name.entry.size(),
+                                                   typeStr.data(), typeStr.size(),
+                                                   name.package.data(), name.package.size());
+        if (!resId.isValid()) {
+            continue;
+        }
+
+        std::shared_ptr<Symbol> s = lookupIdInTable(table, resId);
+        if (s) {
+            mCache.put(name, s);
+            return s.get();
+        }
+    }
+    return nullptr;
+}
+
+const ISymbolTable::Symbol* AssetManagerSymbolTableBuilder::AssetManagerSymbolTable::findById(
+        ResourceId id) {
+    if (const std::shared_ptr<Symbol>& s = mIdCache.get(id)) {
+        return s.get();
+    }
+
+    for (const auto& asset : mAssets) {
+        const android::ResTable& table = asset->getResources(false);
+
+        std::shared_ptr<Symbol> s = lookupIdInTable(table, id);
+        if (s) {
+            mIdCache.put(id, s);
+            return s.get();
+        }
+    }
+    return nullptr;
+}
+
+const ISymbolTable::Symbol* JoinedSymbolTableBuilder::JoinedSymbolTable::findByName(
+        const ResourceName& name) {
+    for (auto& symbolTable : mSymbolTables) {
+        if (const Symbol* s = symbolTable->findByName(name)) {
+            return s;
+        }
+    }
+    return {};
+}
+
+const ISymbolTable::Symbol* JoinedSymbolTableBuilder::JoinedSymbolTable::findById(ResourceId id) {
+    for (auto& symbolTable : mSymbolTables) {
+        if (const Symbol* s = symbolTable->findById(id)) {
+            return s;
+        }
+    }
+    return {};
+}
+
+} // namespace aapt