Remove detach from TensorImpl, handle via Type. (#11337)

Summary:
This is so that TensorImpl does not have to depend on Tensor.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/11337

Differential Revision: D9684421

Pulled By: gchanan

fbshipit-source-id: d2af93420ca6d493429c251cfe5a34e9289c4484

2 files changed, 41 insertions, 1 deletions

diff --git a/tools/autograd/gen_variable_type.py b/tools/autograd/gen_variable_type.py
index 05affcbaa6..d6bcb0821e 100644
--- a/tools/autograd/gen_variable_type.py
+++ b/tools/autograd/gen_variable_type.py
@@ -31,7 +31,7 @@ from .gen_autograd_functions import uses_single_grad
 
 # These functions are written manually in templates/VariableType.cpp
 MANUAL_IMPLEMENTATIONS = {
-    'contiguous', 'resize_', 'resize_as_'
+    'contiguous', 'resize_', 'resize_as_', 'detach', 'detach_',
 }
 
 # These functions we don't want to record for tracing, because we always want
diff --git a/tools/autograd/templates/VariableType.cpp b/tools/autograd/templates/VariableType.cpp
index 031fd9e450..da7be8824e 100644
--- a/tools/autograd/templates/VariableType.cpp
+++ b/tools/autograd/templates/VariableType.cpp
@@ -446,6 +446,46 @@ Tensor VariableType::contiguous(const Tensor & self) const {
   return self.clone();
 }
 
+Tensor VariableType::detach(const Tensor & self) const {
+  profiler::RecordFunction profiler("detach");
+  torch::jit::Node* node = nullptr;
+  if (jit::tracer::isTracing()) {
+    auto& graph = jit::tracer::getTracingState()->graph;
+    node = graph->create(jit::aten::detach, /*outputs=*/0);
+    jit::tracer::recordSourceLocation(node);
+    jit::tracer::addInputs(node, "self", self);
+    graph->appendNode(node);
+
+  }
+  // <NON_GENERATED_CODE>
+  auto result = as_variable_ref(const_cast<Tensor&>(self)).detach();
+  // </NON_GENERATED_CODE>
+  if (jit::tracer::isTracing()) {
+    jit::tracer::addOutput(node, result);
+  }
+  return result;
+}
+
+Tensor & VariableType::detach_(Tensor & self) const {
+  profiler::RecordFunction profiler("detach_");
+  torch::jit::Node* node = nullptr;
+  if (jit::tracer::isTracing()) {
+    auto& graph = jit::tracer::getTracingState()->graph;
+    node = graph->create(jit::aten::detach, /*outputs=*/0);
+    jit::tracer::recordSourceLocation(node);
+    jit::tracer::addInputs(node, "self", self);
+    graph->appendNode(node);
+    jit::tracer::ensureUnique("detach_", self);
+  }
+  // <NON_GENERATED_CODE>
+  as_variable_ref(self).detach_();
+  // </NON_GENERATED_CODE>
+  if (jit::tracer::isTracing()) {
+    jit::tracer::addOutput(node, self);
+  }
+  return self;
+}
+
 static std::vector<std::vector<int64_t>> to_args_sizes(TensorList tensors) {
   std::vector<std::vector<int64_t>> args_sizes(tensors.size());
   for (size_t i = 0; i < tensors.size(); ++i) {