AAPT2

First checking of AAPT2. The individual phases of AAPT2 work, but there
are some missing pieces.

For early testing we are missing:
- Need to properly mark file references and include them in package
- Need to package into zip

Final AAPT for apps we are missing:
- Need to crush PNGs
- Need to parse 9-patches
- Need to validate all of AndroidManifest.xml
- Need to write align method to align resource tables for splits.

Final AAPT for apps + system we are missing:
- Need to handle overlays
- Need to store comments for R file
- Need to handle --shared-lib (dynamic references too).

New AAPT features coming:
- Need to import compiled libraries
    - Name mangling
    - R file generation for library code

Change-Id: I95f8a63581b81a1f424ae6fb2c373c883b72c18d
diff --git a/tools/aapt2/Resolver.h b/tools/aapt2/Resolver.h
new file mode 100644
index 0000000..90a8cd9
--- /dev/null
+++ b/tools/aapt2/Resolver.h
@@ -0,0 +1,109 @@
+/*
+ * 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.
+ */
+
+#ifndef AAPT_RESOLVER_H
+#define AAPT_RESOLVER_H
+
+#include "Maybe.h"
+#include "Resource.h"
+#include "ResourceTable.h"
+#include "ResourceValues.h"
+
+#include <androidfw/AssetManager.h>
+#include <androidfw/ResourceTypes.h>
+#include <memory>
+#include <vector>
+
+namespace aapt {
+
+/**
+ * Resolves symbolic references (package:type/entry) into resource IDs/objects.
+ * Encapsulates the search of library sources as well as the local ResourceTable.
+ */
+class Resolver {
+public:
+    /**
+     * Creates a resolver with a local ResourceTable and an AssetManager
+     * loaded with library packages.
+     */
+    Resolver(std::shared_ptr<const ResourceTable> table,
+             std::shared_ptr<const android::AssetManager> sources);
+
+    Resolver(const Resolver&) = delete; // Not copyable.
+
+    /**
+     * Holds the result of a resource name lookup.
+     */
+    struct Entry {
+        /**
+         * The ID of the resource. ResourceId::isValid() may
+         * return false if the resource has not been assigned
+         * an ID.
+         */
+        ResourceId id;
+
+        /**
+         * If the resource is an attribute, this will point
+         * to a valid Attribute object, or else it will be
+         * nullptr.
+         */
+        const Attribute* attr;
+    };
+
+    /**
+     * Return the package to use when none is specified. This
+     * is the package name of the app being built.
+     */
+    const std::u16string& getDefaultPackage() const;
+
+    /**
+     * Returns a ResourceID if the name is found. The ResourceID
+     * may not be valid if the resource was not assigned an ID.
+     */
+    Maybe<ResourceId> findId(const ResourceName& name);
+
+    /**
+     * Returns an Entry if the name is found. Entry::attr
+     * may be nullptr if the resource is not an attribute.
+     */
+    Maybe<Entry> findAttribute(const ResourceName& name);
+
+    const android::ResTable& getResTable() const;
+
+private:
+    struct CacheEntry {
+        ResourceId id;
+        std::unique_ptr<Attribute> attr;
+    };
+
+    const CacheEntry* buildCacheEntry(const ResourceName& name);
+
+    std::shared_ptr<const ResourceTable> mTable;
+    std::shared_ptr<const android::AssetManager> mSources;
+    std::map<ResourceName, CacheEntry> mCache;
+};
+
+inline const std::u16string& Resolver::getDefaultPackage() const {
+    return mTable->getPackage();
+}
+
+inline const android::ResTable& Resolver::getResTable() const {
+    return mSources->getResources(false);
+}
+
+} // namespace aapt
+
+#endif // AAPT_RESOLVER_H