AAPT2: Define and Implement AAPT Container Format

AAPT Container Format (.apc) is a simple container that
enumerates the various intermediate files that AAPT2 generates
during the compile phase.

The format is defined in formats.md.

For now, continue using the .flat extension for the container file,
and keep making use of the .flata zip for storing multiple files.
This will allow easier integration with existing build systems and allow
the evolution of the APC format to better handle arbitrarily large
files.

Test: make aapt2_tests
Change-Id: Id7216e5b76316bdd683f0fa4eaf2d2da273ba815
diff --git a/tools/aapt2/link/TableMerger.cpp b/tools/aapt2/link/TableMerger.cpp
index 93c904f..21c6b11 100644
--- a/tools/aapt2/link/TableMerger.cpp
+++ b/tools/aapt2/link/TableMerger.cpp
@@ -37,13 +37,12 @@
   CHECK(master_package_ != nullptr) << "package name or ID already taken";
 }
 
-bool TableMerger::Merge(const Source& src, ResourceTable* table, io::IFileCollection* collection) {
-  return MergeImpl(src, table, collection, false /*overlay*/, true /*allow_new*/);
-}
-
-bool TableMerger::MergeOverlay(const Source& src, ResourceTable* table,
-                               io::IFileCollection* collection) {
-  return MergeImpl(src, table, collection, true /*overlay*/, options_.auto_add_overlay);
+bool TableMerger::Merge(const Source& src, ResourceTable* table, bool overlay,
+                        io::IFileCollection* collection) {
+  // We allow adding new resources if this is not an overlay, or if the options allow overlays
+  // to add new resources.
+  return MergeImpl(src, table, collection, overlay,
+                   options_.auto_add_overlay || !overlay /*allow_new*/);
 }
 
 // This will merge packages with the same package name (or no package name).
@@ -322,17 +321,20 @@
         util::make_unique<FileReference>(master_table_->string_pool.MakeRef(newPath));
     new_file_ref->SetComment(file_ref.GetComment());
     new_file_ref->SetSource(file_ref.GetSource());
+    new_file_ref->type = file_ref.type;
+    new_file_ref->file = file_ref.file;
     return new_file_ref;
   }
   return std::unique_ptr<FileReference>(file_ref.Clone(&master_table_->string_pool));
 }
 
-bool TableMerger::MergeFileImpl(const ResourceFile& file_desc, io::IFile* file, bool overlay) {
+bool TableMerger::MergeFile(const ResourceFile& file_desc, bool overlay, io::IFile* file) {
   ResourceTable table;
   std::string path = ResourceUtils::BuildResourceFileName(file_desc);
   std::unique_ptr<FileReference> file_ref =
       util::make_unique<FileReference>(table.string_pool.MakeRef(path));
   file_ref->SetSource(file_desc.source);
+  file_ref->type = file_desc.type;
   file_ref->file = file;
 
   ResourceTablePackage* pkg = table.CreatePackage(file_desc.name.package, 0x0);
@@ -341,17 +343,8 @@
       ->FindOrCreateValue(file_desc.config, {})
       ->value = std::move(file_ref);
 
-  return DoMerge(file->GetSource(), &table, pkg, false /* mangle */,
-                 overlay /* overlay */, true /* allow_new */, {});
-}
-
-bool TableMerger::MergeFile(const ResourceFile& file_desc, io::IFile* file) {
-  return MergeFileImpl(file_desc, file, false /* overlay */);
-}
-
-bool TableMerger::MergeFileOverlay(const ResourceFile& file_desc,
-                                   io::IFile* file) {
-  return MergeFileImpl(file_desc, file, true /* overlay */);
+  return DoMerge(file->GetSource(), &table, pkg, false /* mangle */, overlay /* overlay */,
+                 true /* allow_new */, {});
 }
 
 }  // namespace aapt