Error on duplicate resource with same disabled flag

Also realized I hadn't handled flag negation so added that as well.

Test: Automated
Bug: 329436914
Flag: EXEMPT Aconfig not supported on host tools
Change-Id: If90ae71070306f8e0c367be7e652da9c7bd0bb22

22 files changed, 402 insertions, 77 deletions

diff --git a/core/tests/resourceflaggingtests/src/com/android/resourceflaggingtests/ResourceFlaggingTest.java b/core/tests/resourceflaggingtests/src/com/android/resourceflaggingtests/ResourceFlaggingTest.java
index 005538a4d401..89c7582f4131 100644
--- a/core/tests/resourceflaggingtests/src/com/android/resourceflaggingtests/ResourceFlaggingTest.java
+++ b/core/tests/resourceflaggingtests/src/com/android/resourceflaggingtests/ResourceFlaggingTest.java
@@ -78,6 +78,16 @@ public class ResourceFlaggingTest {
     }
 
     @Test
+    public void testNegatedDisabledFlag() {
+        assertThat(mResources.getBoolean(R.bool.bool5)).isTrue();
+    }
+
+    @Test
+    public void testNegatedEnabledFlag() {
+        assertThat(mResources.getBoolean(R.bool.bool6)).isTrue();
+    }
+
+    @Test
     public void testFlagEnabledDifferentCompilationUnit() {
         assertThat(mResources.getBoolean(R.bool.bool3)).isTrue();
     }
diff --git a/tools/aapt2/Debug.cpp b/tools/aapt2/Debug.cpp
index df1d51e37660..064b4617b0a2 100644
--- a/tools/aapt2/Debug.cpp
+++ b/tools/aapt2/Debug.cpp
@@ -346,6 +346,21 @@ void Debug::PrintTable(const ResourceTable& table, const DebugPrintTableOptions&
             value->value->Accept(&body_printer);
             printer->Undent();
           }
+          printer->Println("Flag disabled values:");
+          for (const auto& value : entry.flag_disabled_values) {
+            printer->Print("(");
+            printer->Print(value->config.to_string());
+            printer->Print(") ");
+            value->value->Accept(&headline_printer);
+            if (options.show_sources && !value->value->GetSource().path.empty()) {
+              printer->Print(" src=");
+              printer->Print(value->value->GetSource().to_string());
+            }
+            printer->Println();
+            printer->Indent();
+            value->value->Accept(&body_printer);
+            printer->Undent();
+          }
           printer->Undent();
         }
       }
diff --git a/tools/aapt2/Resource.h b/tools/aapt2/Resource.h
index a274f047586c..446fdd4dbc1b 100644
--- a/tools/aapt2/Resource.h
+++ b/tools/aapt2/Resource.h
@@ -71,6 +71,17 @@ enum class ResourceType {
 
 enum class FlagStatus { NoFlag = 0, Disabled = 1, Enabled = 2 };
 
+struct FeatureFlagAttribute {
+  std::string name;
+  bool negated = false;
+
+  std::string ToString() {
+    return (negated ? "!" : "") + name;
+  }
+
+  bool operator==(const FeatureFlagAttribute& o) const = default;
+};
+
 android::StringPiece to_string(ResourceType type);
 
 /**
diff --git a/tools/aapt2/ResourceParser.cpp b/tools/aapt2/ResourceParser.cpp
index a5aecc855707..773edc3e3c22 100644
--- a/tools/aapt2/ResourceParser.cpp
+++ b/tools/aapt2/ResourceParser.cpp
@@ -107,9 +107,10 @@ struct ParsedResource {
   Visibility::Level visibility_level = Visibility::Level::kUndefined;
   bool staged_api = false;
   bool allow_new = false;
-  FlagStatus flag_status = FlagStatus::NoFlag;
   std::optional<OverlayableItem> overlayable_item;
   std::optional<StagedId> staged_alias;
+  std::optional<FeatureFlagAttribute> flag;
+  FlagStatus flag_status;
 
   std::string comment;
   std::unique_ptr<Value> value;
@@ -151,6 +152,7 @@ static bool AddResourcesToTable(ResourceTable* table, android::IDiagnostics* dia
   }
 
   if (res->value != nullptr) {
+    res->value->SetFlag(res->flag);
     res->value->SetFlagStatus(res->flag_status);
     // Attach the comment, source and config to the value.
     res->value->SetComment(std::move(res->comment));
@@ -162,8 +164,6 @@ static bool AddResourcesToTable(ResourceTable* table, android::IDiagnostics* dia
     res_builder.SetStagedId(res->staged_alias.value());
   }
 
-  res_builder.SetFlagStatus(res->flag_status);
-
   bool error = false;
   if (!res->name.entry.empty()) {
     if (!table->AddResource(res_builder.Build(), diag)) {
@@ -547,11 +547,15 @@ bool ResourceParser::ParseResource(xml::XmlPullParser* parser,
   });
 
   std::string resource_type = parser->element_name();
-  auto flag_status = GetFlagStatus(parser);
-  if (!flag_status) {
+  out_resource->flag = GetFlag(parser);
+  std::string error;
+  auto flag_status = GetFlagStatus(out_resource->flag, options_.feature_flag_values, &error);
+  if (flag_status) {
+    out_resource->flag_status = flag_status.value();
+  } else {
+    diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number())) << error);
     return false;
   }
-  out_resource->flag_status = flag_status.value();
 
   // The value format accepted for this resource.
   uint32_t resource_format = 0u;
@@ -733,31 +737,20 @@ bool ResourceParser::ParseResource(xml::XmlPullParser* parser,
   return false;
 }
 
-std::optional<FlagStatus> ResourceParser::GetFlagStatus(xml::XmlPullParser* parser) {
-  auto flag_status = FlagStatus::NoFlag;
-
-  std::optional<StringPiece> flag = xml::FindAttribute(parser, xml::kSchemaAndroid, "featureFlag");
-  if (flag) {
-    auto flag_it = options_.feature_flag_values.find(flag.value());
-    if (flag_it == options_.feature_flag_values.end()) {
-      diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
-                   << "Resource flag value undefined");
-      return {};
-    }
-    const auto& flag_properties = flag_it->second;
-    if (!flag_properties.read_only) {
-      diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
-                   << "Only read only flags may be used with resources");
-      return {};
-    }
-    if (!flag_properties.enabled.has_value()) {
-      diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
-                   << "Only flags with a value may be used with resources");
-      return {};
+std::optional<FeatureFlagAttribute> ResourceParser::GetFlag(xml::XmlPullParser* parser) {
+  auto name = xml::FindAttribute(parser, xml::kSchemaAndroid, "featureFlag");
+  if (name) {
+    FeatureFlagAttribute flag;
+    if (name->starts_with('!')) {
+      flag.negated = true;
+      flag.name = name->substr(1);
+    } else {
+      flag.name = name.value();
     }
-    flag_status = flag_properties.enabled.value() ? FlagStatus::Enabled : FlagStatus::Disabled;
+    return flag;
+  } else {
+    return {};
   }
-  return flag_status;
 }
 
 bool ResourceParser::ParseItem(xml::XmlPullParser* parser,
@@ -1666,21 +1659,25 @@ bool ResourceParser::ParseArrayImpl(xml::XmlPullParser* parser,
     const std::string& element_namespace = parser->element_namespace();
     const std::string& element_name = parser->element_name();
     if (element_namespace.empty() && element_name == "item") {
-      auto flag_status = GetFlagStatus(parser);
-      if (!flag_status) {
-        error = true;
-        continue;
-      }
+      auto flag = GetFlag(parser);
       std::unique_ptr<Item> item = ParseXml(parser, typeMask, kNoRawString);
       if (!item) {
         diag_->Error(android::DiagMessage(item_source) << "could not parse array item");
         error = true;
         continue;
       }
-      item->SetFlagStatus(flag_status.value());
+      item->SetFlag(flag);
+      std::string err;
+      auto status = GetFlagStatus(flag, options_.feature_flag_values, &err);
+      if (status) {
+        item->SetFlagStatus(status.value());
+      } else {
+        diag_->Error(android::DiagMessage(item_source) << err);
+        error = true;
+        continue;
+      }
       item->SetSource(item_source);
       array->elements.emplace_back(std::move(item));
-
     } else if (!ShouldIgnoreElement(element_namespace, element_name)) {
       diag_->Error(android::DiagMessage(source_.WithLine(parser->line_number()))
                    << "unknown tag <" << element_namespace << ":" << element_name << ">");
diff --git a/tools/aapt2/ResourceParser.h b/tools/aapt2/ResourceParser.h
index 442dea89ef40..a789d3e90770 100644
--- a/tools/aapt2/ResourceParser.h
+++ b/tools/aapt2/ResourceParser.h
@@ -85,7 +85,7 @@ class ResourceParser {
  private:
   DISALLOW_COPY_AND_ASSIGN(ResourceParser);
 
-  std::optional<FlagStatus> GetFlagStatus(xml::XmlPullParser* parser);
+  std::optional<FeatureFlagAttribute> GetFlag(xml::XmlPullParser* parser);
 
   std::optional<FlattenedXmlSubTree> CreateFlattenSubTree(xml::XmlPullParser* parser);
 
diff --git a/tools/aapt2/ResourceTable.cpp b/tools/aapt2/ResourceTable.cpp
index 97514599c0b1..5435cba290fc 100644
--- a/tools/aapt2/ResourceTable.cpp
+++ b/tools/aapt2/ResourceTable.cpp
@@ -101,6 +101,21 @@ struct lt_config_key_ref {
   }
 };
 
+struct ConfigFlagKey {
+  const ConfigDescription* config;
+  StringPiece product;
+  const FeatureFlagAttribute& flag;
+};
+
+struct lt_config_flag_key_ref {
+  template <typename T>
+  bool operator()(const T& lhs, const ConfigFlagKey& rhs) const noexcept {
+    return std::tie(lhs->config, lhs->product, lhs->value->GetFlag()->name,
+                    lhs->value->GetFlag()->negated) <
+           std::tie(*rhs.config, rhs.product, rhs.flag.name, rhs.flag.negated);
+  }
+};
+
 }  // namespace
 
 ResourceTable::ResourceTable(ResourceTable::Validation validation) : validation_(validation) {
@@ -213,6 +228,25 @@ std::vector<ResourceConfigValue*> ResourceEntry::FindAllValues(const ConfigDescr
   return results;
 }
 
+ResourceConfigValue* ResourceEntry::FindOrCreateFlagDisabledValue(
+    const FeatureFlagAttribute& flag, const android::ConfigDescription& config,
+    android::StringPiece product) {
+  auto iter = std::lower_bound(flag_disabled_values.begin(), flag_disabled_values.end(),
+                               ConfigFlagKey{&config, product, flag}, lt_config_flag_key_ref());
+  if (iter != flag_disabled_values.end()) {
+    ResourceConfigValue* value = iter->get();
+    const auto value_flag = value->value->GetFlag().value();
+    if (value_flag.name == flag.name && value_flag.negated == flag.negated &&
+        value->config == config && value->product == product) {
+      return value;
+    }
+  }
+  ResourceConfigValue* newValue =
+      flag_disabled_values.insert(iter, util::make_unique<ResourceConfigValue>(config, product))
+          ->get();
+  return newValue;
+}
+
 bool ResourceEntry::HasDefaultValue() const {
   // The default config should be at the top of the list, since the list is sorted.
   return !values.empty() && values.front()->config == ConfigDescription::DefaultConfig();
@@ -375,13 +409,14 @@ struct EntryViewComparer {
   }
 };
 
-void InsertEntryIntoTableView(ResourceTableView& table, const ResourceTablePackage* package,
-                              const ResourceTableType* type, const std::string& entry_name,
-                              const std::optional<ResourceId>& id, const Visibility& visibility,
-                              const std::optional<AllowNew>& allow_new,
-                              const std::optional<OverlayableItem>& overlayable_item,
-                              const std::optional<StagedId>& staged_id,
-                              const std::vector<std::unique_ptr<ResourceConfigValue>>& values) {
+void InsertEntryIntoTableView(
+    ResourceTableView& table, const ResourceTablePackage* package, const ResourceTableType* type,
+    const std::string& entry_name, const std::optional<ResourceId>& id,
+    const Visibility& visibility, const std::optional<AllowNew>& allow_new,
+    const std::optional<OverlayableItem>& overlayable_item,
+    const std::optional<StagedId>& staged_id,
+    const std::vector<std::unique_ptr<ResourceConfigValue>>& values,
+    const std::vector<std::unique_ptr<ResourceConfigValue>>& flag_disabled_values) {
   SortedVectorInserter<ResourceTablePackageView, PackageViewComparer> package_inserter;
   SortedVectorInserter<ResourceTableTypeView, TypeViewComparer> type_inserter;
   SortedVectorInserter<ResourceTableEntryView, EntryViewComparer> entry_inserter;
@@ -408,6 +443,9 @@ void InsertEntryIntoTableView(ResourceTableView& table, const ResourceTablePacka
   for (auto& value : values) {
     new_entry.values.emplace_back(value.get());
   }
+  for (auto& value : flag_disabled_values) {
+    new_entry.flag_disabled_values.emplace_back(value.get());
+  }
 
   entry_inserter.Insert(view_type->entries, std::move(new_entry));
 }
@@ -426,6 +464,21 @@ const ResourceConfigValue* ResourceTableEntryView::FindValue(const ConfigDescrip
   return nullptr;
 }
 
+const ResourceConfigValue* ResourceTableEntryView::FindFlagDisabledValue(
+    const FeatureFlagAttribute& flag, const ConfigDescription& config,
+    android::StringPiece product) const {
+  auto iter = std::lower_bound(flag_disabled_values.begin(), flag_disabled_values.end(),
+                               ConfigFlagKey{&config, product, flag}, lt_config_flag_key_ref());
+  if (iter != values.end()) {
+    const ResourceConfigValue* value = *iter;
+    if (value->value->GetFlag() == flag && value->config == config &&
+        StringPiece(value->product) == product) {
+      return value;
+    }
+  }
+  return nullptr;
+}
+
 ResourceTableView ResourceTable::GetPartitionedView(const ResourceTableViewOptions& options) const {
   ResourceTableView view;
   for (const auto& package : packages) {
@@ -433,13 +486,13 @@ ResourceTableView ResourceTable::GetPartitionedView(const ResourceTableViewOptio
       for (const auto& entry : type->entries) {
         InsertEntryIntoTableView(view, package.get(), type.get(), entry->name, entry->id,
                                  entry->visibility, entry->allow_new, entry->overlayable_item,
-                                 entry->staged_id, entry->values);
+                                 entry->staged_id, entry->values, entry->flag_disabled_values);
 
         if (options.create_alias_entries && entry->staged_id) {
           auto alias_id = entry->staged_id.value().id;
           InsertEntryIntoTableView(view, package.get(), type.get(), entry->name, alias_id,
                                    entry->visibility, entry->allow_new, entry->overlayable_item, {},
-                                   entry->values);
+                                   entry->values, entry->flag_disabled_values);
         }
       }
     }
@@ -587,6 +640,25 @@ bool ResourceTable::AddResource(NewResource&& res, android::IDiagnostics* diag)
     entry->staged_id = res.staged_id.value();
   }
 
+  if (res.value != nullptr && res.value->GetFlagStatus() == FlagStatus::Disabled) {
+    auto disabled_config_value =
+        entry->FindOrCreateFlagDisabledValue(res.value->GetFlag().value(), res.config, res.product);
+    if (!disabled_config_value->value) {
+      // Resource does not exist, add it now.
+      // Must clone the value since it might be in the values vector as well
+      CloningValueTransformer cloner(&string_pool);
+      disabled_config_value->value = res.value->Transform(cloner);
+    } else {
+      diag->Error(android::DiagMessage(source)
+                  << "duplicate value for resource '" << res.name << "' " << "with config '"
+                  << res.config << "' and flag '"
+                  << (res.value->GetFlag().value().negated ? "!" : "")
+                  << res.value->GetFlag().value().name << "'");
+      diag->Error(android::DiagMessage(source) << "resource previously defined here");
+      return false;
+    }
+  }
+
   if (res.value != nullptr) {
     auto config_value = entry->FindOrCreateValue(res.config, res.product);
     if (!config_value->value) {
@@ -595,9 +667,9 @@ bool ResourceTable::AddResource(NewResource&& res, android::IDiagnostics* diag)
     } else {
       // When validation is enabled, ensure that a resource cannot have multiple values defined for
       // the same configuration unless protected by flags.
-      auto result =
-          validate ? ResolveFlagCollision(config_value->value->GetFlagStatus(), res.flag_status)
-                   : CollisionResult::kKeepBoth;
+      auto result = validate ? ResolveFlagCollision(config_value->value->GetFlagStatus(),
+                                                    res.value->GetFlagStatus())
+                             : CollisionResult::kKeepBoth;
       if (result == CollisionResult::kConflict) {
         result = ResolveValueCollision(config_value->value.get(), res.value.get());
       }
@@ -771,11 +843,6 @@ NewResourceBuilder& NewResourceBuilder::SetAllowMangled(bool allow_mangled) {
   return *this;
 }
 
-NewResourceBuilder& NewResourceBuilder::SetFlagStatus(FlagStatus flag_status) {
-  res_.flag_status = flag_status;
-  return *this;
-}
-
 NewResource NewResourceBuilder::Build() {
   return std::move(res_);
 }
diff --git a/tools/aapt2/ResourceTable.h b/tools/aapt2/ResourceTable.h
index cba6b70cfbd6..b0e185536d16 100644
--- a/tools/aapt2/ResourceTable.h
+++ b/tools/aapt2/ResourceTable.h
@@ -136,6 +136,9 @@ class ResourceEntry {
   // The resource's values for each configuration.
   std::vector<std::unique_ptr<ResourceConfigValue>> values;
 
+  // The resource's values that are behind disabled flags.
+  std::vector<std::unique_ptr<ResourceConfigValue>> flag_disabled_values;
+
   explicit ResourceEntry(android::StringPiece name) : name(name) {
   }
 
@@ -148,6 +151,13 @@ class ResourceEntry {
                                          android::StringPiece product);
   std::vector<ResourceConfigValue*> FindAllValues(const android::ConfigDescription& config);
 
+  // Either returns the existing ResourceConfigValue in the disabled list with the given flag,
+  // config, and product or creates a new one and returns that. In either case the returned value
+  // does not have the flag set on the value so it must be set by the caller.
+  ResourceConfigValue* FindOrCreateFlagDisabledValue(const FeatureFlagAttribute& flag,
+                                                     const android::ConfigDescription& config,
+                                                     android::StringPiece product = {});
+
   template <typename Func>
   std::vector<ResourceConfigValue*> FindValuesIf(Func f) {
     std::vector<ResourceConfigValue*> results;
@@ -215,9 +225,14 @@ struct ResourceTableEntryView {
   std::optional<OverlayableItem> overlayable_item;
   std::optional<StagedId> staged_id;
   std::vector<const ResourceConfigValue*> values;
+  std::vector<const ResourceConfigValue*> flag_disabled_values;
 
   const ResourceConfigValue* FindValue(const android::ConfigDescription& config,
                                        android::StringPiece product = {}) const;
+
+  const ResourceConfigValue* FindFlagDisabledValue(const FeatureFlagAttribute& flag,
+                                                   const android::ConfigDescription& config,
+                                                   android::StringPiece product = {}) const;
 };
 
 struct ResourceTableTypeView {
@@ -269,7 +284,6 @@ struct NewResource {
   std::optional<AllowNew> allow_new;
   std::optional<StagedId> staged_id;
   bool allow_mangled = false;
-  FlagStatus flag_status = FlagStatus::NoFlag;
 };
 
 struct NewResourceBuilder {
@@ -283,7 +297,6 @@ struct NewResourceBuilder {
   NewResourceBuilder& SetAllowNew(AllowNew allow_new);
   NewResourceBuilder& SetStagedId(StagedId id);
   NewResourceBuilder& SetAllowMangled(bool allow_mangled);
-  NewResourceBuilder& SetFlagStatus(FlagStatus flag_status);
   NewResource Build();
 
  private:
diff --git a/tools/aapt2/ResourceValues.cpp b/tools/aapt2/ResourceValues.cpp
index b75e87c90128..723cfc0e035b 100644
--- a/tools/aapt2/ResourceValues.cpp
+++ b/tools/aapt2/ResourceValues.cpp
@@ -1102,6 +1102,7 @@ template <typename T>
 std::unique_ptr<T> CopyValueFields(std::unique_ptr<T> new_value, const T* value) {
   new_value->SetSource(value->GetSource());
   new_value->SetComment(value->GetComment());
+  new_value->SetFlag(value->GetFlag());
   new_value->SetFlagStatus(value->GetFlagStatus());
   return new_value;
 }
diff --git a/tools/aapt2/ResourceValues.h b/tools/aapt2/ResourceValues.h
index a1b1839b19ef..e000c653b87a 100644
--- a/tools/aapt2/ResourceValues.h
+++ b/tools/aapt2/ResourceValues.h
@@ -65,10 +65,21 @@ class Value {
     return translatable_;
   }
 
+  void SetFlag(std::optional<FeatureFlagAttribute> val) {
+    flag_ = val;
+  }
+
+  std::optional<FeatureFlagAttribute> GetFlag() const {
+    return flag_;
+  }
+
   void SetFlagStatus(FlagStatus val) {
     flag_status_ = val;
   }
 
+  // If the value is behind a flag this returns whether that flag was enabled when the value was
+  // parsed by comparing it to the flags passed on the command line to aapt2 (taking into account
+  // negation if necessary). If there was no flag, FlagStatus::NoFlag is returned instead.
   FlagStatus GetFlagStatus() const {
     return flag_status_;
   }
@@ -128,6 +139,7 @@ class Value {
   std::string comment_;
   bool weak_ = false;
   bool translatable_ = true;
+  std::optional<FeatureFlagAttribute> flag_;
   FlagStatus flag_status_ = FlagStatus::NoFlag;
 
  private:
diff --git a/tools/aapt2/Resources.proto b/tools/aapt2/Resources.proto
index 5c6408940b34..a0f60b62db3a 100644
--- a/tools/aapt2/Resources.proto
+++ b/tools/aapt2/Resources.proto
@@ -240,6 +240,9 @@ message Entry {
 
   // The staged resource ID of this finalized resource.
   StagedId staged_id = 7;
+
+  // The set of values defined for this entry which are behind disabled flags
+  repeated ConfigValue flag_disabled_config_value = 8;
 }
 
 // A Configuration/Value pair.
@@ -283,6 +286,8 @@ message Item {
 
   // The status of the flag the value is behind if any
   uint32 flag_status = 8;
+  bool flag_negated = 9;
+  string flag_name = 10;
 }
 
 // A CompoundValue is an abstract type. It represents a value that is a made of other values.
diff --git a/tools/aapt2/cmd/Diff.cpp b/tools/aapt2/cmd/Diff.cpp
index 6da3176b2bee..d3750a6100d3 100644
--- a/tools/aapt2/cmd/Diff.cpp
+++ b/tools/aapt2/cmd/Diff.cpp
@@ -138,6 +138,22 @@ static bool EmitResourceEntryDiff(IAaptContext* context, LoadedApk* apk_a,
     }
   }
 
+  for (const ResourceConfigValue* config_value_a : entry_a.flag_disabled_values) {
+    auto config_value_b = entry_b.FindFlagDisabledValue(config_value_a->value->GetFlag().value(),
+                                                        config_value_a->config);
+    if (!config_value_b) {
+      std::stringstream str_stream;
+      str_stream << "missing disabled value " << pkg_a.name << ":" << type_a.named_type << "/"
+                 << entry_a.name << " config=" << config_value_a->config
+                 << " flag=" << config_value_a->value->GetFlag()->ToString();
+      EmitDiffLine(apk_b->GetSource(), str_stream.str());
+      diff = true;
+    } else {
+      diff |= EmitResourceConfigValueDiff(context, apk_a, pkg_a, type_a, entry_a, config_value_a,
+                                          apk_b, pkg_b, type_b, entry_b, config_value_b);
+    }
+  }
+
   // Check for any newly added config values.
   for (const ResourceConfigValue* config_value_b : entry_b.values) {
     auto config_value_a = entry_a.FindValue(config_value_b->config);
@@ -149,6 +165,18 @@ static bool EmitResourceEntryDiff(IAaptContext* context, LoadedApk* apk_a,
       diff = true;
     }
   }
+  for (const ResourceConfigValue* config_value_b : entry_b.flag_disabled_values) {
+    auto config_value_a = entry_a.FindFlagDisabledValue(config_value_b->value->GetFlag().value(),
+                                                        config_value_b->config);
+    if (!config_value_a) {
+      std::stringstream str_stream;
+      str_stream << "new disabled config " << pkg_b.name << ":" << type_b.named_type << "/"
+                 << entry_b.name << " config=" << config_value_b->config
+                 << " flag=" << config_value_b->value->GetFlag()->ToString();
+      EmitDiffLine(apk_b->GetSource(), str_stream.str());
+      diff = true;
+    }
+  }
   return diff;
 }
 
diff --git a/tools/aapt2/cmd/Util.cpp b/tools/aapt2/cmd/Util.cpp
index 7739171b347f..2177c345260c 100644
--- a/tools/aapt2/cmd/Util.cpp
+++ b/tools/aapt2/cmd/Util.cpp
@@ -34,6 +34,30 @@ using ::android::base::StringPrintf;
 
 namespace aapt {
 
+std::optional<FlagStatus> GetFlagStatus(const std::optional<FeatureFlagAttribute>& flag,
+                                        const FeatureFlagValues& feature_flag_values,
+                                        std::string* out_err) {
+  if (!flag) {
+    return FlagStatus::NoFlag;
+  }
+  auto flag_it = feature_flag_values.find(flag->name);
+  if (flag_it == feature_flag_values.end()) {
+    *out_err = "Resource flag value undefined: " + flag->name;
+    return {};
+  }
+  const auto& flag_properties = flag_it->second;
+  if (!flag_properties.read_only) {
+    *out_err = "Only read only flags may be used with resources: " + flag->name;
+    return {};
+  }
+  if (!flag_properties.enabled.has_value()) {
+    *out_err = "Only flags with a value may be used with resources: " + flag->name;
+    return {};
+  }
+  return (flag_properties.enabled.value() != flag->negated) ? FlagStatus::Enabled
+                                                            : FlagStatus::Disabled;
+}
+
 std::optional<uint16_t> ParseTargetDensityParameter(StringPiece arg, android::IDiagnostics* diag) {
   ConfigDescription preferred_density_config;
   if (!ConfigDescription::Parse(arg, &preferred_density_config)) {
diff --git a/tools/aapt2/cmd/Util.h b/tools/aapt2/cmd/Util.h
index 6b8813b34082..f8e44b72247c 100644
--- a/tools/aapt2/cmd/Util.h
+++ b/tools/aapt2/cmd/Util.h
@@ -49,6 +49,10 @@ struct FeatureFlagProperties {
 
 using FeatureFlagValues = std::map<std::string, FeatureFlagProperties, std::less<>>;
 
+std::optional<FlagStatus> GetFlagStatus(const std::optional<FeatureFlagAttribute>& flag,
+                                        const FeatureFlagValues& feature_flag_values,
+                                        std::string* out_err);
+
 // Parses a configuration density (ex. hdpi, xxhdpi, 234dpi, anydpi, etc).
 // Returns Nothing and logs a human friendly error message if the string was not legal.
 std::optional<uint16_t> ParseTargetDensityParameter(android::StringPiece arg,
diff --git a/tools/aapt2/format/proto/ProtoDeserialize.cpp b/tools/aapt2/format/proto/ProtoDeserialize.cpp
index 55f5e5668a16..c6bd6dd3c4b2 100644
--- a/tools/aapt2/format/proto/ProtoDeserialize.cpp
+++ b/tools/aapt2/format/proto/ProtoDeserialize.cpp
@@ -536,6 +536,34 @@ static bool DeserializePackageFromPb(const pb::Package& pb_package, const ResStr
 
         config_value->value = DeserializeValueFromPb(pb_config_value.value(), src_pool, config,
                                                      &out_table->string_pool, files, out_error);
+
+        if (config_value->value == nullptr) {
+          return false;
+        }
+      }
+
+      // flag disabled
+      for (const pb::ConfigValue& pb_config_value : pb_entry.flag_disabled_config_value()) {
+        const pb::Configuration& pb_config = pb_config_value.config();
+
+        ConfigDescription config;
+        if (!DeserializeConfigFromPb(pb_config, &config, out_error)) {
+          return false;
+        }
+
+        FeatureFlagAttribute flag;
+        flag.name = pb_config_value.value().item().flag_name();
+        flag.negated = pb_config_value.value().item().flag_negated();
+        ResourceConfigValue* config_value =
+            entry->FindOrCreateFlagDisabledValue(std::move(flag), config, pb_config.product());
+        if (config_value->value != nullptr) {
+          *out_error = "duplicate configuration in resource table";
+          return false;
+        }
+
+        config_value->value = DeserializeValueFromPb(pb_config_value.value(), src_pool, config,
+                                                     &out_table->string_pool, files, out_error);
+
         if (config_value->value == nullptr) {
           return false;
         }
@@ -748,7 +776,6 @@ std::unique_ptr<Value> DeserializeValueFromPb(const pb::Value& pb_value,
     if (value == nullptr) {
       return {};
     }
-
   } else if (pb_value.has_compound_value()) {
     const pb::CompoundValue& pb_compound_value = pb_value.compound_value();
     switch (pb_compound_value.value_case()) {
@@ -1018,6 +1045,12 @@ std::unique_ptr<Item> DeserializeItemFromPb(const pb::Item& pb_item,
       DeserializeItemFromPbInternal(pb_item, src_pool, config, value_pool, files, out_error);
   if (item) {
     item->SetFlagStatus((FlagStatus)pb_item.flag_status());
+    if (!pb_item.flag_name().empty()) {
+      FeatureFlagAttribute flag;
+      flag.name = pb_item.flag_name();
+      flag.negated = pb_item.flag_negated();
+      item->SetFlag(std::move(flag));
+    }
   }
   return item;
 }
diff --git a/tools/aapt2/format/proto/ProtoSerialize.cpp b/tools/aapt2/format/proto/ProtoSerialize.cpp
index 5772b3b0b3e6..9c28780e7880 100644
--- a/tools/aapt2/format/proto/ProtoSerialize.cpp
+++ b/tools/aapt2/format/proto/ProtoSerialize.cpp
@@ -427,6 +427,14 @@ void SerializeTableToPb(const ResourceTable& table, pb::ResourceTable* out_table
           SerializeValueToPb(*config_value->value, pb_config_value->mutable_value(),
                              source_pool.get());
         }
+
+        for (const ResourceConfigValue* config_value : entry.flag_disabled_values) {
+          pb::ConfigValue* pb_config_value = pb_entry->add_flag_disabled_config_value();
+          SerializeConfig(config_value->config, pb_config_value->mutable_config());
+          pb_config_value->mutable_config()->set_product(config_value->product);
+          SerializeValueToPb(*config_value->value, pb_config_value->mutable_value(),
+                             source_pool.get());
+        }
       }
     }
   }
@@ -721,6 +729,11 @@ void SerializeValueToPb(const Value& value, pb::Value* out_value, android::Strin
   }
   if (out_value->has_item()) {
     out_value->mutable_item()->set_flag_status((uint32_t)value.GetFlagStatus());
+    if (value.GetFlag()) {
+      const auto& flag = value.GetFlag();
+      out_value->mutable_item()->set_flag_negated(flag->negated);
+      out_value->mutable_item()->set_flag_name(flag->name);
+    }
   }
 }
 
@@ -730,6 +743,11 @@ void SerializeItemToPb(const Item& item, pb::Item* out_item) {
   item.Accept(&serializer);
   out_item->MergeFrom(value.item());
   out_item->set_flag_status((uint32_t)item.GetFlagStatus());
+  if (item.GetFlag()) {
+    const auto& flag = item.GetFlag();
+    out_item->set_flag_negated(flag->negated);
+    out_item->set_flag_name(flag->name);
+  }
 }
 
 void SerializeCompiledFileToPb(const ResourceFile& file, pb::internal::CompiledFile* out_file) {
diff --git a/tools/aapt2/integration-tests/FlaggedResourcesTest/res/values/bools.xml b/tools/aapt2/integration-tests/FlaggedResourcesTest/res/values/bools.xml
index 1ed0c8a5f1e6..7837e17b044b 100644
--- a/tools/aapt2/integration-tests/FlaggedResourcesTest/res/values/bools.xml
+++ b/tools/aapt2/integration-tests/FlaggedResourcesTest/res/values/bools.xml
@@ -9,4 +9,10 @@
     <bool name="bool3">false</bool>
 
     <bool name="bool4" android:featureFlag="test.package.falseFlag">true</bool>
+
+    <bool name="bool5">false</bool>
+    <bool name="bool5" android:featureFlag="!test.package.falseFlag">true</bool>
+
+    <bool name="bool6">true</bool>
+    <bool name="bool6" android:featureFlag="!test.package.trueFlag">false</bool>
 </resources>
\ No newline at end of file
diff --git a/tools/aapt2/link/FlaggedResources_test.cpp b/tools/aapt2/link/FlaggedResources_test.cpp
index 3db37c2fa6f8..67d0c41f6b6f 100644
--- a/tools/aapt2/link/FlaggedResources_test.cpp
+++ b/tools/aapt2/link/FlaggedResources_test.cpp
@@ -17,6 +17,7 @@
 #include "LoadedApk.h"
 #include "cmd/Dump.h"
 #include "io/StringStream.h"
+#include "test/Common.h"
 #include "test/Test.h"
 #include "text/Printer.h"
 
@@ -98,4 +99,47 @@ TEST_F(FlaggedResourcesTest, DisabledResourcesInRJava) {
   ASSERT_NE(r_contents.find("public static final int str1"), std::string::npos);
 }
 
+TEST_F(FlaggedResourcesTest, TwoValuesSameDisabledFlag) {
+  test::TestDiagnosticsImpl diag;
+  const std::string compiled_files_dir = GetTestPath("compiled");
+  ASSERT_FALSE(CompileFile(
+      GetTestPath("res/values/values.xml"),
+      R"(<resources xmlns:android="http://schemas.android.com/apk/res/android">
+           <bool name="bool1" android:featureFlag="test.package.falseFlag">false</bool>
+           <bool name="bool1" android:featureFlag="test.package.falseFlag">true</bool>
+         </resources>)",
+      compiled_files_dir, &diag,
+      {"--feature-flags", "test.package.falseFlag:ro=false,test.package.trueFlag:ro=true"}));
+  ASSERT_TRUE(diag.GetLog().contains("duplicate value for resource 'bool/bool1'"));
+}
+
+TEST_F(FlaggedResourcesTest, TwoValuesSameDisabledFlagDifferentFiles) {
+  test::TestDiagnosticsImpl diag;
+  const std::string compiled_files_dir = GetTestPath("compiled");
+  ASSERT_TRUE(CompileFile(
+      GetTestPath("res/values/values1.xml"),
+      R"(<resources xmlns:android="http://schemas.android.com/apk/res/android">
+           <bool name="bool1" android:featureFlag="test.package.falseFlag">false</bool>
+         </resources>)",
+      compiled_files_dir, &diag,
+      {"--feature-flags", "test.package.falseFlag:ro=false,test.package.trueFlag:ro=true"}));
+  ASSERT_TRUE(CompileFile(
+      GetTestPath("res/values/values2.xml"),
+      R"(<resources xmlns:android="http://schemas.android.com/apk/res/android">
+           <bool name="bool1" android:featureFlag="test.package.falseFlag">true</bool>
+         </resources>)",
+      compiled_files_dir, &diag,
+      {"--feature-flags", "test.package.falseFlag:ro=false,test.package.trueFlag:ro=true"}));
+  const std::string out_apk = GetTestPath("out.apk");
+  std::vector<std::string> link_args = {
+      "--manifest",
+      GetDefaultManifest(),
+      "-o",
+      out_apk,
+  };
+
+  ASSERT_FALSE(Link(link_args, compiled_files_dir, &diag));
+  ASSERT_TRUE(diag.GetLog().contains("duplicate value for resource 'bool1'"));
+}
+
 }  // namespace aapt
diff --git a/tools/aapt2/link/TableMerger.cpp b/tools/aapt2/link/TableMerger.cpp
index 37a039e9528f..d21697938c62 100644
--- a/tools/aapt2/link/TableMerger.cpp
+++ b/tools/aapt2/link/TableMerger.cpp
@@ -321,6 +321,30 @@ bool TableMerger::DoMerge(const android::Source& src, ResourceTablePackage* src_
           }
         }
       }
+
+      // disabled values
+      for (auto& src_config_value : src_entry->flag_disabled_values) {
+        auto dst_config_value = dst_entry->FindOrCreateFlagDisabledValue(
+            src_config_value->value->GetFlag().value(), src_config_value->config,
+            src_config_value->product);
+        if (!dst_config_value->value) {
+          // Resource does not exist, add it now.
+          // Must clone the value since it might be in the values vector as well
+          CloningValueTransformer cloner(&main_table_->string_pool);
+          dst_config_value->value = src_config_value->value->Transform(cloner);
+        } else {
+          error = true;
+          context_->GetDiagnostics()->Error(
+              android::DiagMessage(src_config_value->value->GetSource())
+              << "duplicate value for resource '" << src_entry->name << "' " << "with config '"
+              << src_config_value->config << "' and flag '"
+              << (src_config_value->value->GetFlag()->negated ? "!" : "")
+              << src_config_value->value->GetFlag()->name << "'");
+          context_->GetDiagnostics()->Note(
+              android::DiagMessage(dst_config_value->value->GetSource())
+              << "resource previously defined here");
+        }
+      }
     }
   }
   return !error;
diff --git a/tools/aapt2/test/Common.cpp b/tools/aapt2/test/Common.cpp
index cdf245341844..c7dd4c90e67f 100644
--- a/tools/aapt2/test/Common.cpp
+++ b/tools/aapt2/test/Common.cpp
@@ -21,23 +21,6 @@ using android::ConfigDescription;
 namespace aapt {
 namespace test {
 
-struct TestDiagnosticsImpl : public android::IDiagnostics {
-  void Log(Level level, android::DiagMessageActual& actual_msg) override {
-    switch (level) {
-      case Level::Note:
-        return;
-
-      case Level::Warn:
-        std::cerr << actual_msg.source << ": warn: " << actual_msg.message << "." << std::endl;
-        break;
-
-      case Level::Error:
-        std::cerr << actual_msg.source << ": error: " << actual_msg.message << "." << std::endl;
-        break;
-    }
-  }
-};
-
 android::IDiagnostics* GetDiagnostics() {
   static TestDiagnosticsImpl diag;
   return &diag;
diff --git a/tools/aapt2/test/Common.h b/tools/aapt2/test/Common.h
index 04379804d8ee..b06c4329488e 100644
--- a/tools/aapt2/test/Common.h
+++ b/tools/aapt2/test/Common.h
@@ -37,6 +37,32 @@
 namespace aapt {
 namespace test {
 
+struct TestDiagnosticsImpl : public android::IDiagnostics {
+  void Log(Level level, android::DiagMessageActual& actual_msg) override {
+    switch (level) {
+      case Level::Note:
+        return;
+
+      case Level::Warn:
+        std::cerr << actual_msg.source << ": warn: " << actual_msg.message << "." << std::endl;
+        log << actual_msg.source << ": warn: " << actual_msg.message << "." << std::endl;
+        break;
+
+      case Level::Error:
+        std::cerr << actual_msg.source << ": error: " << actual_msg.message << "." << std::endl;
+        log << actual_msg.source << ": error: " << actual_msg.message << "." << std::endl;
+        break;
+    }
+  }
+
+  std::string GetLog() {
+    return log.str();
+  }
+
+ private:
+  std::ostringstream log;
+};
+
 android::IDiagnostics* GetDiagnostics();
 
 inline ResourceName ParseNameOrDie(android::StringPiece str) {
diff --git a/tools/aapt2/test/Fixture.cpp b/tools/aapt2/test/Fixture.cpp
index b91abe572306..570bcf16c92c 100644
--- a/tools/aapt2/test/Fixture.cpp
+++ b/tools/aapt2/test/Fixture.cpp
@@ -91,10 +91,13 @@ void TestDirectoryFixture::WriteFile(const std::string& path, const std::string&
 }
 
 bool CommandTestFixture::CompileFile(const std::string& path, const std::string& contents,
-                                     android::StringPiece out_dir, android::IDiagnostics* diag) {
+                                     android::StringPiece out_dir, android::IDiagnostics* diag,
+                                     const std::vector<android::StringPiece>& additional_args) {
   WriteFile(path, contents);
   CHECK(file::mkdirs(out_dir.data()));
-  return CompileCommand(diag).Execute({path, "-o", out_dir, "-v"}, &std::cerr) == 0;
+  std::vector<android::StringPiece> args = {path, "-o", out_dir, "-v"};
+  args.insert(args.end(), additional_args.begin(), additional_args.end());
+  return CompileCommand(diag).Execute(args, &std::cerr) == 0;
 }
 
 bool CommandTestFixture::Link(const std::vector<std::string>& args, android::IDiagnostics* diag) {
diff --git a/tools/aapt2/test/Fixture.h b/tools/aapt2/test/Fixture.h
index 14298d1678f0..178d01156f32 100644
--- a/tools/aapt2/test/Fixture.h
+++ b/tools/aapt2/test/Fixture.h
@@ -73,7 +73,8 @@ class CommandTestFixture : public TestDirectoryFixture {
   // Wries the contents of the file to the specified path. The file is compiled and the flattened
   // file is written to the out directory.
   bool CompileFile(const std::string& path, const std::string& contents,
-                   android::StringPiece flat_out_dir, android::IDiagnostics* diag);
+                   android::StringPiece flat_out_dir, android::IDiagnostics* diag,
+                   const std::vector<android::StringPiece>& additional_args = {});
 
   // Executes the link command with the specified arguments.
   bool Link(const std::vector<std::string>& args, android::IDiagnostics* diag);