Add enforcement of overlayable targetName

Adds android:targetName to the overlay manifest attributes and
PackageParser reads the name into PackageInfo. Specifying
android:targetName on an overlay allows the overlay to be associated
with a particular set of overlayable resources. The overlay can only
override the values of the resources defined within the target
overlayable element.

Test: idmap2_tests
Bug: 119390855
Bug: 110869880

Change-Id: I1128274af4cae983f61ae15cdfcbface63233ff2
diff --git a/cmds/idmap2/libidmap2/ResourceUtils.cpp b/cmds/idmap2/libidmap2/ResourceUtils.cpp
index 04e0ec7..7a984f3 100644
--- a/cmds/idmap2/libidmap2/ResourceUtils.cpp
+++ b/cmds/idmap2/libidmap2/ResourceUtils.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <memory>
 #include <string>
 
 #include "androidfw/StringPiece.h"
@@ -21,8 +22,13 @@
 
 #include "idmap2/ResourceUtils.h"
 #include "idmap2/Result.h"
+#include "idmap2/Xml.h"
+#include "idmap2/ZipFile.h"
 
 using android::StringPiece16;
+using android::idmap2::Result;
+using android::idmap2::Xml;
+using android::idmap2::ZipFile;
 using android::util::Utf16ToUtf8;
 
 namespace android::idmap2::utils {
@@ -47,4 +53,63 @@
   return {out};
 }
 
+Result<OverlayManifestInfo> ExtractOverlayManifestInfo(const std::string& path,
+                                                       std::ostream& out_error,
+                                                       bool assert_overlay) {
+  std::unique_ptr<const ZipFile> zip = ZipFile::Open(path);
+  if (!zip) {
+    out_error << "error: failed to open " << path << " as a zip file" << std::endl;
+    return kResultError;
+  }
+
+  std::unique_ptr<const MemoryChunk> entry = zip->Uncompress("AndroidManifest.xml");
+  if (!entry) {
+    out_error << "error: failed to uncompress AndroidManifest.xml from " << path << std::endl;
+    return kResultError;
+  }
+
+  std::unique_ptr<const Xml> xml = Xml::Create(entry->buf, entry->size);
+  if (!xml) {
+    out_error << "error: failed to parse AndroidManifest.xml from " << path << std::endl;
+    return kResultError;
+  }
+
+  OverlayManifestInfo info{};
+  const auto tag = xml->FindTag("overlay");
+  if (!tag) {
+    if (assert_overlay) {
+      out_error << "error: <overlay> missing from AndroidManifest.xml of " << path << std::endl;
+      return kResultError;
+    }
+    return info;
+  }
+
+  auto iter = tag->find("targetPackage");
+  if (iter == tag->end()) {
+    if (assert_overlay) {
+      out_error << "error: android:targetPackage missing from <overlay> of " << path << std::endl;
+      return kResultError;
+    }
+  } else {
+    info.target_package = iter->second;
+  }
+
+  iter = tag->find("targetName");
+  if (iter != tag->end()) {
+    info.target_name = iter->second;
+  }
+
+  iter = tag->find("isStatic");
+  if (iter != tag->end()) {
+    info.is_static = std::stoul(iter->second) != 0U;
+  }
+
+  iter = tag->find("priority");
+  if (iter != tag->end()) {
+    info.priority = std::stoi(iter->second);
+  }
+
+  return info;
+}
+
 }  // namespace android::idmap2::utils