Surface <overlayable> info in Java AssetManager

Add a new, hidden method to AssetManager to extract a mapping
overlayable name -> overlayable actor for all <overlayable> blocks in a
package. [This will eventually be used to check if the caller of the OMS
AIDL API is the registered actor for a given overlay.]

Also, teach AssetManager2 to not accept packages that re-use the same
overlayable name. [Such packages have always been ill-formed.]

Bug: 123894537
Test: make libandroidfw_tests
Change-Id: I1117fd3503f04fe4c73eb7114901e022508f4d9e
diff --git a/libs/androidfw/AssetManager2.cpp b/libs/androidfw/AssetManager2.cpp
index 81afd93..66d8542 100644
--- a/libs/androidfw/AssetManager2.cpp
+++ b/libs/androidfw/AssetManager2.cpp
@@ -203,6 +203,27 @@
   return nullptr;
 }
 
+const std::unordered_map<std::string, std::string>*
+  AssetManager2::GetOverlayableMapForPackage(uint32_t package_id) const {
+
+  if (package_id >= package_ids_.size()) {
+    return nullptr;
+  }
+
+  const size_t idx = package_ids_[package_id];
+  if (idx == 0xff) {
+    return nullptr;
+  }
+
+  const PackageGroup& package_group = package_groups_[idx];
+  if (package_group.packages_.size() == 0) {
+    return nullptr;
+  }
+
+  const auto loaded_package = package_group.packages_[0].loaded_package_;
+  return &loaded_package->GetOverlayableMap();
+}
+
 void AssetManager2::SetConfiguration(const ResTable_config& configuration) {
   const int diff = configuration_.diff(configuration);
   configuration_ = configuration;
diff --git a/libs/androidfw/LoadedArsc.cpp b/libs/androidfw/LoadedArsc.cpp
index bdd4706..72873ab 100644
--- a/libs/androidfw/LoadedArsc.cpp
+++ b/libs/androidfw/LoadedArsc.cpp
@@ -598,6 +598,13 @@
         std::string actor;
         util::ReadUtf16StringFromDevice(header->actor, arraysize(header->actor), &actor);
 
+        if (loaded_package->overlayable_map_.find(name) !=
+            loaded_package->overlayable_map_.end()) {
+          LOG(ERROR) << "Multiple <overlayable> blocks with the same name '" << name << "'.";
+          return {};
+        }
+        loaded_package->overlayable_map_.emplace(name, actor);
+
         // Iterate over the overlayable policy chunks contained within the overlayable chunk data
         ChunkIterator overlayable_iter(child_chunk.data_ptr(), child_chunk.data_size());
         while (overlayable_iter.HasNext()) {
diff --git a/libs/androidfw/include/androidfw/AssetManager2.h b/libs/androidfw/include/androidfw/AssetManager2.h
index d862182..fc5aa9c7 100644
--- a/libs/androidfw/include/androidfw/AssetManager2.h
+++ b/libs/androidfw/include/androidfw/AssetManager2.h
@@ -124,6 +124,9 @@
   // This may be nullptr if the APK represented by `cookie` has no resource table.
   const DynamicRefTable* GetDynamicRefTableForCookie(ApkAssetsCookie cookie) const;
 
+  const std::unordered_map<std::string, std::string>*
+    GetOverlayableMapForPackage(uint32_t package_id) const;
+
   // Sets/resets the configuration for this AssetManager. This will cause all
   // caches that are related to the configuration change to be invalidated.
   void SetConfiguration(const ResTable_config& configuration);
diff --git a/libs/androidfw/include/androidfw/LoadedArsc.h b/libs/androidfw/include/androidfw/LoadedArsc.h
index b5f4006..950f541 100644
--- a/libs/androidfw/include/androidfw/LoadedArsc.h
+++ b/libs/androidfw/include/androidfw/LoadedArsc.h
@@ -20,6 +20,7 @@
 #include <memory>
 #include <set>
 #include <vector>
+#include <unordered_map>
 #include <unordered_set>
 
 #include "android-base/macros.h"
@@ -242,6 +243,10 @@
     return defines_overlayable_;
   }
 
+  const std::unordered_map<std::string, std::string>& GetOverlayableMap() const {
+    return overlayable_map_;
+  }
+
  private:
   DISALLOW_COPY_AND_ASSIGN(LoadedPackage);
 
@@ -261,6 +266,7 @@
   ByteBucketArray<uint32_t> resource_ids_;
   std::vector<DynamicPackageEntry> dynamic_package_map_;
   std::vector<const std::pair<OverlayableInfo, std::unordered_set<uint32_t>>> overlayable_infos_;
+  std::unordered_map<std::string, std::string> overlayable_map_;
 };
 
 // Read-only view into a resource table. This class validates all data
diff --git a/libs/androidfw/tests/AssetManager2_test.cpp b/libs/androidfw/tests/AssetManager2_test.cpp
index 447fdf5..40c8e46 100644
--- a/libs/androidfw/tests/AssetManager2_test.cpp
+++ b/libs/androidfw/tests/AssetManager2_test.cpp
@@ -71,6 +71,9 @@
 
     app_assets_ = ApkAssets::Load(GetTestDataPath() + "/app/app.apk");
     ASSERT_THAT(app_assets_, NotNull());
+
+    overlayable_assets_ = ApkAssets::Load(GetTestDataPath() + "/overlayable/overlayable.apk");
+    ASSERT_THAT(overlayable_assets_, NotNull());
   }
 
  protected:
@@ -83,6 +86,7 @@
   std::unique_ptr<const ApkAssets> appaslib_assets_;
   std::unique_ptr<const ApkAssets> system_assets_;
   std::unique_ptr<const ApkAssets> app_assets_;
+  std::unique_ptr<const ApkAssets> overlayable_assets_;
 };
 
 TEST_F(AssetManager2Test, FindsResourceFromSingleApkAssets) {
@@ -703,4 +707,20 @@
   EXPECT_EQ("", resultDisabled);
 }
 
+TEST_F(AssetManager2Test, GetOverlayableMap) {
+  ResTable_config desired_config;
+  memset(&desired_config, 0, sizeof(desired_config));
+
+  AssetManager2 assetmanager;
+  assetmanager.SetResourceResolutionLoggingEnabled(true);
+  assetmanager.SetConfiguration(desired_config);
+  assetmanager.SetApkAssets({overlayable_assets_.get()});
+
+  const auto map = assetmanager.GetOverlayableMapForPackage(0x7f);
+  ASSERT_NE(nullptr, map);
+  ASSERT_EQ(2, map->size());
+  ASSERT_EQ(map->at("OverlayableResources1"), "overlay://theme");
+  ASSERT_EQ(map->at("OverlayableResources2"), "overlay://com.android.overlayable");
+}
+
 }  // namespace android
diff --git a/libs/androidfw/tests/LoadedArsc_test.cpp b/libs/androidfw/tests/LoadedArsc_test.cpp
index b8d3c6b..d58e8d2 100644
--- a/libs/androidfw/tests/LoadedArsc_test.cpp
+++ b/libs/androidfw/tests/LoadedArsc_test.cpp
@@ -331,7 +331,7 @@
 
   const std::vector<std::unique_ptr<const LoadedPackage>>& packages = loaded_arsc->GetPackages();
   ASSERT_EQ(1u, packages.size());
-  EXPECT_EQ(std::string("com.android.basic"), packages[0]->GetPackageName());
+  ASSERT_EQ(std::string("com.android.basic"), packages[0]->GetPackageName());
 
   const auto& loaded_package = packages[0];
   auto iter = loaded_package->begin();
@@ -369,6 +369,24 @@
   ASSERT_EQ(end, iter);
 }
 
+TEST(LoadedArscTest, GetOverlayableMap) {
+  std::string contents;
+  ASSERT_TRUE(ReadFileFromZipToString(GetTestDataPath() + "/overlayable/overlayable.apk",
+                                      "resources.arsc", &contents));
+
+  std::unique_ptr<const LoadedArsc> loaded_arsc = LoadedArsc::Load(StringPiece(contents));
+  ASSERT_NE(nullptr, loaded_arsc);
+
+  const std::vector<std::unique_ptr<const LoadedPackage>>& packages = loaded_arsc->GetPackages();
+  ASSERT_EQ(1u, packages.size());
+  ASSERT_EQ(std::string("com.android.overlayable"), packages[0]->GetPackageName());
+
+  const auto map = packages[0]->GetOverlayableMap();
+  ASSERT_EQ(2, map.size());
+  ASSERT_EQ(map.at("OverlayableResources1"), "overlay://theme");
+  ASSERT_EQ(map.at("OverlayableResources2"), "overlay://com.android.overlayable");
+}
+
 // structs with size fields (like Res_value, ResTable_entry) should be
 // backwards and forwards compatible (aka checking the size field against
 // sizeof(Res_value) might not be backwards compatible.