[Eager] Support test_var_base _offset in eager mode (#41369)

* [Eager]Polish enable/disable_legacy_dygraph logic

* Support _offset in eager mode

* Update framework.py

* Update framework.py
Co-authored-by: NAurelius84 <zhangliujie@baidu.com>

paddle/fluid/pybind/eager_method.cc

@@ -1344,6 +1344,19 @@ static PyObject* tensor__reset_grad_inplace_version(TensorObject* self,
   EAGER_CATCH_AND_THROW_RETURN_NULL
 }
 
+static PyObject* tensor__offset(TensorObject* self, PyObject* args,
+                                PyObject* kwargs) {
+  EAGER_TRY
+  auto t = std::dynamic_pointer_cast<phi::DenseTensor>(self->tensor.impl());
+  PADDLE_ENFORCE_EQ(
+      t->IsInitialized(), true,
+      platform::errors::InvalidArgument("Tensor %s has not been initialized!",
+                                        self->tensor.name()));
+
+  return ToPyObject(t->offset());
+  EAGER_CATCH_AND_THROW_RETURN_NULL
+}
+
 #if defined(PADDLE_WITH_CUDA)
 static PyObject* tensor_method__uva(TensorObject* self, PyObject* args,
                                     PyObject* kwargs) {
@@ -1472,6 +1485,8 @@ PyMethodDef variable_methods[] = {
     {"_reset_grad_inplace_version",
      (PyCFunction)(void (*)(void))tensor__reset_grad_inplace_version,
      METH_VARARGS | METH_KEYWORDS, NULL},
+    {"_offset", (PyCFunction)(void (*)(void))tensor__offset,
+     METH_VARARGS | METH_KEYWORDS, NULL},
 #if defined(PADDLE_WITH_CUDA)
     {"_tensor_uva", (PyCFunction)(void (*)(void))tensor_method__uva,
      METH_VARARGS | METH_KEYWORDS, NULL},

paddle/fluid/pybind/eager_utils.cc

@@ -426,6 +426,8 @@ PyObject* ToPyObject(int value) { return PyLong_FromLong(value); }
 
 PyObject* ToPyObject(uint32_t value) { return PyLong_FromUnsignedLong(value); }
 
+PyObject* ToPyObject(size_t value) { return PyLong_FromLong(value); }
+
 PyObject* ToPyObject(int64_t value) { return PyLong_FromLongLong(value); }
 
 PyObject* ToPyObject(float value) { return PyLong_FromDouble(value); }

paddle/fluid/pybind/eager_utils.h

@@ -55,6 +55,7 @@ framework::proto::VarType::Type CastPyArg2ProtoType(PyObject* obj,
 
 PyObject* ToPyObject(int value);
 PyObject* ToPyObject(uint32_t value);
+PyObject* ToPyObject(size_t value);
 PyObject* ToPyObject(bool value);
 PyObject* ToPyObject(int64_t value);
 PyObject* ToPyObject(float value);

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

@@ -1396,7 +1396,7 @@ class TestVarBaseClear(unittest.TestCase):
 
 
 class TestVarBaseOffset(unittest.TestCase):
-    def test_offset(self):
+    def func_offset(self):
         paddle.disable_static()
         np_x = np.random.random((3, 8, 8))
         x = paddle.to_tensor(np_x, dtype="float64")
@@ -1405,6 +1405,11 @@ class TestVarBaseOffset(unittest.TestCase):
         actual_x = paddle.to_tensor(actual_x)
         self.assertEqual(actual_x._offset(), expected_offset)
 
+    def test_offset(self):
+        with _test_eager_guard():
+            self.func_offset()
+        self.func_offset()
+
 
 class TestVarBaseShareBufferTo(unittest.TestCase):
     def test_share_buffer_To(self):