Reapply "Make functionalization ViewMeta serializable with pickle. (#143712)" (#163769)

### Summary: NOTE: This is a re-export of https://github.com/pytorch/pytorch/pull/161994 ; the changes between these two PRs is exclusively to the buck/build files (Summary from #161994 ) Attempted rebase of https://github.com/pytorch/pytorch/pull/143712. This reverts commit 6c713ccb5e0df227dd5b630057cbccd373cbe7d6. cc voznesenskym penguinwu EikanWang jgong5 Guobing-Chen XiaobingSuper zhuhaozhe blzheng wenzhe-nrv jiayisunx chenyang78 kadeng chauhang amjames Lucaskabela imported-using-ghimport Test Plan: Imported from OSS Differential Revision: D81524507 Pulled By: Lucaskabela Pull Request resolved: https://github.com/pytorch/pytorch/pull/163769 Approved by: https://github.com/dolpm Co-authored-by: Brian Hirsh <hirsheybar@fb.com>
2025-10-21 13:44:15 +08:00 · 2025-09-25 10:27:37 +00:00
parent 29cbcbac42
commit 7d710403b0
38 changed files with 981 additions and 425 deletions
--- a/torch/csrc/functionalization/Module.cpp
+++ b/torch/csrc/functionalization/Module.cpp
@ -0,0 +1,71 @@
+#include <torch/csrc/functionalization/Module.h>
+#include <torch/csrc/utils/pybind.h>
+
+#include <ATen/FunctionalStorageImpl.h>
+#include <ATen/FunctionalTensorWrapper.h>
+#include <ATen/FunctionalizeFallbackKernel.h>
+#include <memory>
+
+namespace torch::functionalization {
+
+void initModule(PyObject* module) {
+  auto m = py::handle(module).cast<py::module>();
+
+  // Create a `torch._C._functionalization` Python module.
+  auto functionalization = m.def_submodule(
+      "_functionalization", "functionalization related pybind.");
+
+  // Retrieve the ViewMeta sequence of a given functional tensor.
+  functionalization.def("get_view_meta_sequence", [](const at::Tensor& tensor) {
+    TORCH_INTERNAL_ASSERT(
+        at::functionalization::impl::isFunctionalTensor(tensor));
+    auto impl = at::functionalization::impl::unsafeGetFunctionalWrapper(tensor);
+    return impl->view_metas();
+  });
+
+  // Applies the given ViewMeta sequence to the given base.
+  functionalization.def(
+      "apply_view_meta_sequence",
+      [](const at::Tensor& base,
+         const std::vector<std::shared_ptr<at::functionalization::ViewMeta>>&
+             sequence) {
+        return at::functionalization::impl::apply_view_meta_sequence(
+            base, sequence);
+      });
+
+  // Binding for InverseReturnMode.
+  py::enum_<at::functionalization::InverseReturnMode>(
+      functionalization, "InverseReturnMode")
+      .value("AlwaysView", at::functionalization::InverseReturnMode::AlwaysView)
+      .value("NeverView", at::functionalization::InverseReturnMode::NeverView)
+      .value(
+          "ViewOrScatterInverse",
+          at::functionalization::InverseReturnMode::ViewOrScatterInverse);
+
+  // Create bindings for the ViewMeta base class.
+  //
+  // Needed so that we can take a list of ViewMeta objects as parameter.
+  // Specifically, in the Python-side, we will have a list of derived ViewMeta
+  // classes. We need to tell pybind11 that all of those are, in fact, instances
+  // of different ViewMeta sub-types.
+  py::class_<
+      at::functionalization::ViewMeta,
+      std::shared_ptr<at::functionalization::ViewMeta>>(
+      functionalization, "ViewMeta")
+      .def_property_readonly(
+          "has_symbolic_inputs",
+          [](const std::shared_ptr<at::functionalization::ViewMeta>& meta) {
+            return meta->has_symbolic_inputs;
+          });
+
+  // Bindings for `ViewMeta` specializations manually implemented.
+  create_binding_with_pickle<at::functionalization::resize__ViewMeta>(
+      functionalization);
+  create_binding_with_pickle<at::functionalization::_unsafe_view_ViewMeta>(
+      functionalization);
+
+  // Bindings for `ViewMeta` specializations automatically generated.
+  initGenerated(functionalization.ptr());
+}
+
+} // namespace torch::functionalization