Persist whether xml resources have flags

This stores whether an xml document has feature flags in it in a
ResTable_entry so that at runtime we can know not to do extra work
looking for flags.

Test: Automation
Bug: 377974898
Flag: android.content.res.layout_readwrite_flags

Change-Id: Id43b2d9941d1fab8c654d081bf19df5a33a464f3

2 files changed, 71 insertions, 28 deletions

diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index a18c5f5f92f6..8ecd6ba9b253 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -6520,41 +6520,79 @@ base::expected<StringPiece16, NullOrIOError> StringPoolRef::string16() const {
 }
 
 bool ResTable::getResourceFlags(uint32_t resID, uint32_t* outFlags) const {
-    if (mError != NO_ERROR) {
-        return false;
-    }
+  if (mError != NO_ERROR) {
+    return false;
+  }
 
-    const ssize_t p = getResourcePackageIndex(resID);
-    const int t = Res_GETTYPE(resID);
-    const int e = Res_GETENTRY(resID);
+  const ssize_t p = getResourcePackageIndex(resID);
+  const int t = Res_GETTYPE(resID);
+  const int e = Res_GETENTRY(resID);
 
-    if (p < 0) {
-        if (Res_GETPACKAGE(resID)+1 == 0) {
-            ALOGW("No package identifier when getting flags for resource number 0x%08x", resID);
-        } else {
-            ALOGW("No known package when getting flags for resource number 0x%08x", resID);
-        }
-        return false;
-    }
-    if (t < 0) {
-        ALOGW("No type identifier when getting flags for resource number 0x%08x", resID);
-        return false;
+  if (p < 0) {
+    if (Res_GETPACKAGE(resID)+1 == 0) {
+      ALOGW("No package identifier when getting flags for resource number 0x%08x", resID);
+    } else {
+      ALOGW("No known package when getting flags for resource number 0x%08x", resID);
     }
+    return false;
+  }
+  if (t < 0) {
+    ALOGW("No type identifier when getting flags for resource number 0x%08x", resID);
+    return false;
+  }
 
-    const PackageGroup* const grp = mPackageGroups[p];
-    if (grp == NULL) {
-        ALOGW("Bad identifier when getting flags for resource number 0x%08x", resID);
-        return false;
-    }
+  const PackageGroup* const grp = mPackageGroups[p];
+  if (grp == NULL) {
+    ALOGW("Bad identifier when getting flags for resource number 0x%08x", resID);
+    return false;
+  }
 
-    Entry entry;
-    status_t err = getEntry(grp, t, e, NULL, &entry);
-    if (err != NO_ERROR) {
-        return false;
+  Entry entry;
+  status_t err = getEntry(grp, t, e, NULL, &entry);
+  if (err != NO_ERROR) {
+    return false;
+  }
+
+  *outFlags = entry.specFlags;
+  return true;
+}
+
+bool ResTable::getResourceEntryFlags(uint32_t resID, uint32_t* outFlags) const {
+  if (mError != NO_ERROR) {
+    return false;
+  }
+
+  const ssize_t p = getResourcePackageIndex(resID);
+  const int t = Res_GETTYPE(resID);
+  const int e = Res_GETENTRY(resID);
+
+  if (p < 0) {
+    if (Res_GETPACKAGE(resID)+1 == 0) {
+      ALOGW("No package identifier when getting flags for resource number 0x%08x", resID);
+    } else {
+      ALOGW("No known package when getting flags for resource number 0x%08x", resID);
     }
+    return false;
+  }
+  if (t < 0) {
+    ALOGW("No type identifier when getting flags for resource number 0x%08x", resID);
+    return false;
+  }
 
-    *outFlags = entry.specFlags;
-    return true;
+  const PackageGroup* const grp = mPackageGroups[p];
+  if (grp == NULL) {
+    ALOGW("Bad identifier when getting flags for resource number 0x%08x", resID);
+    return false;
+  }
+
+  Entry entry;
+  status_t err = getEntry(grp, t, e, NULL, &entry);
+  if (err != NO_ERROR) {
+    return false;
+  }
+
+  *outFlags = entry.entry->flags();
+  return true;
 }
 
 bool ResTable::isPackageDynamic(uint8_t packageID) const {
diff --git a/libs/androidfw/include/androidfw/ResourceTypes.h b/libs/androidfw/include/androidfw/ResourceTypes.h
index 0d45149267cf..63b28da075cd 100644
--- a/libs/androidfw/include/androidfw/ResourceTypes.h
+++ b/libs/androidfw/include/androidfw/ResourceTypes.h
@@ -1593,6 +1593,8 @@ union ResTable_entry
         // If set, this is a compact entry with data type and value directly
         // encoded in the this entry, see ResTable_entry::compact
         FLAG_COMPACT = 0x0008,
+        // If set, this entry relies on read write android feature flags
+        FLAG_USES_FEATURE_FLAGS = 0x0010,
     };
 
     struct Full {
@@ -1622,6 +1624,7 @@ union ResTable_entry
     uint16_t flags()  const { return dtohs(full.flags); };
     bool is_compact() const { return flags() & FLAG_COMPACT; }
     bool is_complex() const { return flags() & FLAG_COMPLEX; }
+    bool uses_feature_flags() const { return flags() & FLAG_USES_FEATURE_FLAGS; }
 
     size_t size() const {
         return is_compact() ? sizeof(ResTable_entry) : dtohs(this->full.size);
@@ -2039,6 +2042,8 @@ public:
 
     bool getResourceFlags(uint32_t resID, uint32_t* outFlags) const;
 
+    bool getResourceEntryFlags(uint32_t resID, uint32_t* outFlags) const;
+
     /**
      * Returns whether or not the package for the given resource has been dynamically assigned.
      * If the resource can't be found, returns 'false'.