Keep disabled resources out of final apk

Test: Automated
Bug: 329436914
Flag: EXEMPT Aconfig not supported on host tools
Change-Id: Id5fdb025f004788ea40bdbd0b0df0dbda181f2c7
diff --git a/tools/aapt2/link/FlagDisabledResourceRemover.cpp b/tools/aapt2/link/FlagDisabledResourceRemover.cpp
new file mode 100644
index 0000000..e3289e2
--- /dev/null
+++ b/tools/aapt2/link/FlagDisabledResourceRemover.cpp
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "link/FlagDisabledResourceRemover.h"
+
+#include <algorithm>
+
+#include "ResourceTable.h"
+
+using android::ConfigDescription;
+
+namespace aapt {
+
+static bool KeepResourceEntry(const std::unique_ptr<ResourceEntry>& entry) {
+  if (entry->values.empty()) {
+    return true;
+  }
+  const auto end_iter = entry->values.end();
+  const auto remove_iter =
+      std::stable_partition(entry->values.begin(), end_iter,
+                            [](const std::unique_ptr<ResourceConfigValue>& value) -> bool {
+                              return value->flag_status != FlagStatus::Disabled;
+                            });
+
+  bool keep = remove_iter != entry->values.begin();
+
+  entry->values.erase(remove_iter, end_iter);
+  return keep;
+}
+
+bool FlagDisabledResourceRemover::Consume(IAaptContext* context, ResourceTable* table) {
+  for (auto& pkg : table->packages) {
+    for (auto& type : pkg->types) {
+      const auto end_iter = type->entries.end();
+      const auto remove_iter = std::stable_partition(
+          type->entries.begin(), end_iter, [](const std::unique_ptr<ResourceEntry>& entry) -> bool {
+            return KeepResourceEntry(entry);
+          });
+
+      type->entries.erase(remove_iter, end_iter);
+    }
+  }
+  return true;
+}
+
+}  // namespace aapt
\ No newline at end of file
diff --git a/tools/aapt2/link/FlagDisabledResourceRemover.h b/tools/aapt2/link/FlagDisabledResourceRemover.h
new file mode 100644
index 0000000..2db2cb4
--- /dev/null
+++ b/tools/aapt2/link/FlagDisabledResourceRemover.h
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "android-base/macros.h"
+#include "process/IResourceTableConsumer.h"
+
+namespace aapt {
+
+// Removes any resource that are behind disabled flags.
+class FlagDisabledResourceRemover : public IResourceTableConsumer {
+ public:
+  FlagDisabledResourceRemover() = default;
+
+  bool Consume(IAaptContext* context, ResourceTable* table) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(FlagDisabledResourceRemover);
+};
+
+}  // namespace aapt
diff --git a/tools/aapt2/link/FlaggedResources_test.cpp b/tools/aapt2/link/FlaggedResources_test.cpp
index 03c4ac9..c901b58 100644
--- a/tools/aapt2/link/FlaggedResources_test.cpp
+++ b/tools/aapt2/link/FlaggedResources_test.cpp
@@ -40,7 +40,25 @@
   output_stream.Flush();
 }
 
-TEST_F(FlaggedResourcesTest, DisabledStringRemoved) {
+void DumpResourceTableToString(LoadedApk* loaded_apk, std::string* output) {
+  StringOutputStream output_stream(output);
+  Printer printer(&output_stream);
+
+  DumpTableCommand command(&printer, &noop_diag);
+  ASSERT_EQ(command.Dump(loaded_apk), 0);
+  output_stream.Flush();
+}
+
+void DumpChunksToString(LoadedApk* loaded_apk, std::string* output) {
+  StringOutputStream output_stream(output);
+  Printer printer(&output_stream);
+
+  DumpChunks command(&printer, &noop_diag);
+  ASSERT_EQ(command.Dump(loaded_apk), 0);
+  output_stream.Flush();
+}
+
+TEST_F(FlaggedResourcesTest, DisabledStringRemovedFromPool) {
   auto apk_path = file::BuildPath({android::base::GetExecutableDirectory(), "resapp.apk"});
   auto loaded_apk = LoadedApk::LoadApkFromPath(apk_path, &noop_diag);
 
@@ -51,4 +69,33 @@
   ASSERT_EQ(output.find(excluded), std::string::npos);
 }
 
+TEST_F(FlaggedResourcesTest, DisabledResourcesRemovedFromTable) {
+  auto apk_path = file::BuildPath({android::base::GetExecutableDirectory(), "resapp.apk"});
+  auto loaded_apk = LoadedApk::LoadApkFromPath(apk_path, &noop_diag);
+
+  std::string output;
+  DumpResourceTableToString(loaded_apk.get(), &output);
+}
+
+TEST_F(FlaggedResourcesTest, DisabledResourcesRemovedFromTableChunks) {
+  auto apk_path = file::BuildPath({android::base::GetExecutableDirectory(), "resapp.apk"});
+  auto loaded_apk = LoadedApk::LoadApkFromPath(apk_path, &noop_diag);
+
+  std::string output;
+  DumpChunksToString(loaded_apk.get(), &output);
+
+  ASSERT_EQ(output.find("res4"), std::string::npos);
+  ASSERT_EQ(output.find("str1"), std::string::npos);
+}
+
+TEST_F(FlaggedResourcesTest, DisabledResourcesInRJava) {
+  auto r_path = file::BuildPath({android::base::GetExecutableDirectory(), "resource-flagging-java",
+                                 "com", "android", "intenal", "flaggedresources", "R.java"});
+  std::string r_contents;
+  ::android::base::ReadFileToString(r_path, &r_contents);
+
+  ASSERT_NE(r_contents.find("public static final int res4"), std::string::npos);
+  ASSERT_NE(r_contents.find("public static final int str1"), std::string::npos);
+}
+
 }  // namespace aapt