赛题七-开发grad_fn、next_functions两个API 并暴露到python端-v1 (#54838)

* [尝试] 给tensor增加一个属性, 这个属性是一个定值 1

* 暴露gradnode 并构建gradnode新的方法(用来测试)进行暴露给python python端可以访问

* 开发grad_fn、next_functions两个API 并暴露到python端- 做一些规范化处理

* 增加一个单元测试

* 优化 code-style

paddle/fluid/eager/grad_node_info.cc

@@ -559,4 +559,20 @@ void GradNodeBase::HandleComplexGradToRealGrad(
   }
 }
 
+std::vector<std::shared_ptr<GradNodeBase>> GradNodeBase::NextFunctions() {
+  std::vector<std::shared_ptr<GradNodeBase>> next_nodes;
+  const paddle::small_vector<std::vector<GradSlotMeta>, kSlotSmallVectorSize>&
+      metas = OutputMeta();
+
+  for (const auto& meta_list : metas) {
+    for (const GradSlotMeta& meta : meta_list) {
+      const auto& edge = meta.GetEdge();
+      std::shared_ptr<GradNodeBase> next_node = edge.GetMutableGradNode();
+      next_nodes.push_back(next_node);
+    }
+  }
+
+  return next_nodes;
+}
+
 }  // namespace egr

paddle/fluid/eager/grad_node_info.h

@@ -251,6 +251,8 @@ class GradNodeBase {
     return true;
   }
 
+  std::vector<std::shared_ptr<egr::GradNodeBase>> NextFunctions();
+
   /**
    * Apply GradientHook
    * **/

paddle/fluid/pybind/eager_properties.cc

@@ -22,6 +22,7 @@ limitations under the License. */
 #include "paddle/fluid/eager/api/all.h"
 #include "paddle/fluid/eager/autograd_meta.h"
 #include "paddle/fluid/eager/utils.h"
+#include "paddle/fluid/imperative/op_base.h"
 #include "paddle/fluid/memory/allocation/allocator.h"
 #include "paddle/fluid/memory/memcpy.h"
 #include "paddle/fluid/platform/enforce.h"
@@ -31,6 +32,7 @@ limitations under the License. */
 #include "paddle/phi/common/data_type.h"
 #include "paddle/phi/core/compat/convert_utils.h"
 #include "paddle/phi/core/dense_tensor.h"
+
 #pragma GCC diagnostic ignored "-Wwrite-strings"
 
 namespace paddle {
@@ -301,6 +303,41 @@ PyObject* tensor_properties_get_dtype(TensorObject* self, void* closure) {
   EAGER_CATCH_AND_THROW_RETURN_NULL
 }
 
+PyObject* tensor_properties_get_grad_fn(TensorObject* self, void* closure) {
+  EAGER_TRY
+  if (!self->tensor.defined()) {
+    // Handle undefined tensors if necessary; otherwise, return nullptr or an
+    // appropriate PyObject. In this case, I will return Py_None.
+    Py_INCREF(Py_None);
+    return Py_None;
+  }
+
+  // Get GradNode from the tensor
+  auto meta = egr::EagerUtils::nullable_autograd_meta(
+      self->tensor);  // If meta exists, get the GradNode
+
+  if (meta) {
+    // Get the GradNode from meta
+    auto grad_node = meta->GradNode();  // Convert GradNode to a Python object
+    // The conversion will depend on the structure of GradNode.
+
+    if (!grad_node) {
+      Py_INCREF(Py_None);
+      return Py_None;
+    }
+
+    PyObject* py_grad_node = ToPyObject(grad_node);
+
+    return py_grad_node;
+  } else {
+    // If meta does not exist, return an appropriate Python object (e.g., None
+    // or a special value).
+    Py_INCREF(Py_None);
+    return Py_None;
+  }
+  EAGER_CATCH_AND_THROW_RETURN_NULL
+}
+
 struct PyGetSetDef variable_properties[] = {
     {"grad",
      (getter)tensor_properties_get_grad,
@@ -341,6 +378,11 @@ struct PyGetSetDef variable_properties[] = {
     {"dtype", (getter)tensor_properties_get_dtype, nullptr, nullptr, nullptr},
     {"type", (getter)tensor_properties_get_type, nullptr, nullptr, nullptr},
     {"is_leaf", (getter)tensor_properties_is_leaf, nullptr, nullptr, nullptr},
+    {"grad_fn",
+     (getter)tensor_properties_get_grad_fn,
+     nullptr,
+     nullptr,
+     nullptr},
     {nullptr, nullptr, nullptr, nullptr, nullptr}};
 
 // variable_properties for core.eager.StringTensor

paddle/fluid/pybind/eager_utils.cc

@@ -1006,6 +1006,14 @@ paddle::optional<paddle::Tensor> GetOptionalTensorFromArgs(
   }
 }
 
+PyObject* ToPyObject(egr::GradNodeBase* grad_node) {
+  py::object py_obj = py::cast(grad_node, py::return_value_policy::reference);
+  py::handle py_handle = py::handle(py_obj);
+  PyObject* py_grad_node = py_handle.ptr();
+  Py_INCREF(py_grad_node);
+  return py_grad_node;
+}
+
 static paddle::Tensor& GetTensorFromPyObject(const std::string& op_type,
                                              const std::string& arg_name,
                                              PyObject* obj,

paddle/fluid/pybind/eager_utils.h

@@ -21,6 +21,7 @@ typedef SSIZE_T ssize_t;
 #undef copysign
 #endif
 
+#include "paddle/fluid/eager/grad_node_info.h"
 #include "paddle/fluid/eager/hooks.h"
 #include "paddle/fluid/framework/lod_tensor.h"
 #include "paddle/fluid/framework/lod_tensor_array.h"
@@ -125,6 +126,8 @@ PyObject* ToPyObject(
     const std::unordered_map<std::string, std::vector<std::string>>& value);
 PyObject* ToPyObject(const paddle::framework::Vocab& value);
 
+PyObject* ToPyObject(egr::GradNodeBase* grad_node);
+
 class PyTensorHook : public egr::TensorHook {
  public:
   explicit PyTensorHook(PyObject* func) : py_func_(func) {

paddle/fluid/pybind/pybind.cc

@@ -13,6 +13,8 @@ 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 <Python.h>
+#include "paddle/fluid/eager/grad_node_info.h"
+
 // Avoid a problem with copysign defined in pyconfig.h on Windows.
 #ifdef copysign
 #undef copysign
@@ -776,6 +778,13 @@ PYBIND11_MODULE(libpaddle, m) {
           }
         });
 
+  py::class_<egr::GradNodeBase>(m, "GradNodeBase")
+      .def("name", &egr::GradNodeBase::name)
+      .def_property_readonly("next_functions",
+                             &egr::GradNodeBase::NextFunctions)
+      .def("input_meta", &egr::GradNodeBase::InputMeta)
+      .def("output_meta", &egr::GradNodeBase::OutputMeta);
+
 #if defined(PADDLE_WITH_CUDA) || defined(PADDLE_WITH_HIP)
   m.def("cudnn_version", &platform::DnnVersion);
   m.def("gpu_memory_available", []() {

python/paddle/fluid/tests/unittests/test_grad_fn_and_next_functions.py

+# Copyright (c) 2023 PaddlePaddle 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.
+"""
+Test the tensor attribute grad_fn and the properties of the reverse node grad_node, such as next_function
+"""
+
+import unittest
+
+import paddle
+import paddle.nn as nn
+
+
+class Testmodel(nn.Layer):
+    def __init__(self):
+        super(Testmodel, self).__init__()
+
+    def forward(self, x):
+        y = x**2
+        y = x + y
+        return y
+
+
+class TestAnonmousSurvey(unittest.TestCase):
+    """
+    Test the tensor attribute grad_fn and the properties of the reverse node grad_node, such as next_function
+
+    """
+
+    def init_graph(self):
+        """define reversed graph
+
+        func_name [str]: represents the name of the operator node
+        next_funcs [dict]: represents the operator node
+        """
+        self.grad_fn_1 = {"func_name": "GradNodeAccumulation", "next_funcs": {}}
+        self.grad_fn_2 = {
+            "func_name": "PowGradNode",
+            "next_funcs": {"GradNodeAccumulation": self.grad_fn_1},
+        }
+        self.grad_fn_3 = {
+            "func_name": "AddGradNode",
+            "next_funcs": {
+                "GradNodeAccumulation": self.grad_fn_1,
+                "PowGradNode": self.grad_fn_2,
+            },
+        }
+        self.output_grad_fn = {"grad_fn": self.grad_fn_3}
+
+    def init_data(self):
+        """define output of model
+
+        the final output will be saved self.output
+        """
+        model = Testmodel()
+        x = paddle.randn([1, 3, 24, 24])
+        x.stop_gradient = False
+        self.output = model(x)
+
+    def setUp(self):
+        self.init_graph()
+        self.init_data()
+
+    def test_grad_fn_and_next_funs(self):
+        self.check_func(self.output.grad_fn, self.output_grad_fn["grad_fn"])
+
+    def check_func(self, grad_fn: grad_fn, grad_fn_json: dict) -> None:
+        """
+        Check each node, grad_fn is tensor attribute. grad_fn_json is structure of next_node.
+
+        Args:
+            grad_fn (grad_fn): grad_fn of node
+            grad_fn_json (dict): grad_node_json of node
+        """
+        # print(grad_fn.name())
+        # assert func name
+        self.assertEqual(grad_fn.name(), grad_fn_json["func_name"])
+        # Recursively test other nodes
+        if hasattr(grad_fn, 'next_functions') and grad_fn.next_functions[0]:
+            next_funcs_json = grad_fn_json["next_funcs"]
+            for u in grad_fn.next_functions:
+                self.check_func(u, next_funcs_json[u.name()])
+
+
+unittest.main()