[C++ API] Step 10: add the new ATen tensor conversion files

This PR adds the files implementing the ATen user-facing tensor conversion.

This will avoid leaking DLManagedTensors and ScopeGuard at each call site.

As part of the bigger refactoring, these files are not yet activated
(or even compiled) therefore the changeset cannot be tested independently.
This new implementation will be switched in as part of the last commit of the
global refactoring.

Author: nicolasvasilache

tc/aten/aten-inl.h

@@ -0,0 +1,50 @@
+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * 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 <string>
+#include <vector>
+
+#include <ATen/ATen.h>
+#include <ATen/DLConvertor.h>
+
+#include "tc/core/tensor.h"
+
+namespace tc {
+namespace aten {
+inline std::vector<DLTensorUPtr> makeDLTensors(
+    const std::vector<at::Tensor>& tensors) {
+  std::vector<DLTensorUPtr> dlTensors;
+  for (auto tensor : tensors) {
+    auto dlMTensor = at::toDLPack(tensor);
+    dlTensors.push_back(makeDLTensor(&(dlMTensor->dl_tensor)));
+    dlMTensor->deleter(dlMTensor);
+  }
+  return dlTensors;
+}
+
+inline std::vector<DLConstTensorUPtr> makeDLConstTensors(
+    const std::vector<at::Tensor>& tensors) {
+  std::vector<DLConstTensorUPtr> dlTensors;
+  for (auto tensor : tensors) {
+    auto dlMTensor = at::toDLPack(tensor);
+    dlTensors.push_back(makeDLConstTensor(&(dlMTensor->dl_tensor)));
+    dlMTensor->deleter(dlMTensor);
+  }
+  return dlTensors;
+}
+} // namespace aten
+} // namespace tc

tc/aten/aten.h

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+/**
+ * Copyright (c) 2017-present, Facebook, Inc.
+ *
+ * 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 <string>
+#include <vector>
+
+#include <ATen/ATen.h>
+
+#include "tc/core/tensor.h"
+
+namespace tc {
+namespace aten {
+
+inline std::vector<DLTensorUPtr> makeDLTensors(
+    const std::vector<at::Tensor>& tensors);
+
+inline std::vector<DLConstTensorUPtr> makeDLConstTensors(
+    const std::vector<at::Tensor>& tensors);
+
+} // namespace aten
+} // namespace tc
+
+#include "tc/aten/aten-inl.h"