chore: import upstream snapshot with attribution

tensorflow/lite/nnapi/sl/SupportLibrary.cc

@@ -0,0 +1,93 @@
+/* Copyright 2021 The TensorFlow Authors. All Rights Reserved.
+
+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.
+==============================================================================*/
+
+// Changed when importing from AOSP
+#include "tensorflow/lite/nnapi/sl/include/SupportLibrary.h"
+
+// Changed when importing from AOSP
+#include <dlfcn.h>
+
+#include <cinttypes>
+#include <memory>
+#include <string>
+
+#include "tensorflow/lite/minimal_logging.h"
+#include "tensorflow/lite/nnapi/NeuralNetworksTypes.h"
+
+namespace tflite {
+namespace nnapi {
+
+using tflite::TFLITE_LOG_ERROR;
+
+std::unique_ptr<const NnApiSupportLibrary> loadNnApiSupportLibrary(
+    const std::string& libName) {
+  void* libHandle = dlopen(libName.c_str(), RTLD_LAZY | RTLD_LOCAL);
+  if (libHandle == nullptr) {
+    TFLITE_LOG(TFLITE_LOG_ERROR, "nnapi error: unable to open library %s: %s",
+               libName.c_str(), dlerror());
+    return nullptr;
+  }
+
+  auto result = loadNnApiSupportLibrary(libHandle);
+  if (!result) {
+    dlclose(libHandle);
+  }
+  return result;
+}
+
+std::unique_ptr<const NnApiSupportLibrary> loadNnApiSupportLibrary(
+    void* libHandle) {
+  NnApiSLDriverImpl* (*getSlDriverImpl)();
+  getSlDriverImpl = reinterpret_cast<decltype(getSlDriverImpl)>(
+      dlsym(libHandle, "ANeuralNetworks_getSLDriverImpl"));
+  if (getSlDriverImpl == nullptr) {
+    TFLITE_LOG(TFLITE_LOG_ERROR,
+               "Failed to find ANeuralNetworks_getSLDriverImpl symbol");
+    return nullptr;
+  }
+
+  NnApiSLDriverImpl* impl = getSlDriverImpl();
+  if (impl == nullptr) {
+    TFLITE_LOG(TFLITE_LOG_ERROR,
+               "ANeuralNetworks_getSLDriverImpl returned nullptr");
+    return nullptr;
+  }
+
+  if (impl->implFeatureLevel < ANEURALNETWORKS_FEATURE_LEVEL_5 ||
+      impl->implFeatureLevel > ANEURALNETWORKS_FEATURE_LEVEL_7) {
+    TFLITE_LOG(TFLITE_LOG_ERROR,
+               "Unsupported NnApiSLDriverImpl->implFeatureLevel: %" PRId64,
+               impl->implFeatureLevel);
+    return nullptr;
+  }
+
+  if (impl->implFeatureLevel == ANEURALNETWORKS_FEATURE_LEVEL_5) {
+    return std::make_unique<NnApiSupportLibrary>(
+        reinterpret_cast<NnApiSLDriverImplFL5*>(impl), libHandle);
+  }
+  if (impl->implFeatureLevel == ANEURALNETWORKS_FEATURE_LEVEL_6) {
+    return std::make_unique<NnApiSupportLibrary>(
+        reinterpret_cast<NnApiSLDriverImplFL6*>(impl), libHandle);
+  }
+  if (impl->implFeatureLevel == ANEURALNETWORKS_FEATURE_LEVEL_7) {
+    return std::make_unique<NnApiSupportLibrary>(
+        reinterpret_cast<NnApiSLDriverImplFL7*>(impl), libHandle);
+  }
+
+  return nullptr;
+}
+
+}  // namespace nnapi
+}  // namespace tflite