throw warning at __getitem__, not slice_utils (#53579)

paddle/fluid/pybind/eager_method.cc

@@ -925,15 +925,29 @@ static PyObject* tensor__getitem_index_not_tensor(TensorObject* self,
   }
 
   bool set_to_1d = FLAGS_set_to_1d;
-  if (!none_axes.empty()) {
+
   if (set_to_1d) {
     // NOTE(zoooo0820): When all axes are decreased, the output will be 1-D
     // with FLAGS_set_to_1d=True. In this case, one `None` should be pop out,
     // otherwise the output shape will be not correct.
     if (static_cast<int>(decrease_axis.size()) == tensor->dims().size()) {
+      VLOG(0)
+          << "Warning: In Tensor '__getitem__', if the number of scalar "
+             "elements "
+             "in the index is equal to the rank of the Tensor, the output "
+             "should "
+             "be 0-D. In order to be consistent with the behavior of previous "
+             "versions, it will be processed to 1-D. But it is not correct and "
+             "will be "
+             "removed in release 2.6. "
+             "If 1-D is still wanted, please modify the index element from "
+             "scalar to slice "
+             "(e.g. 'x[i]' => 'x[i:i+1]'). ";
+      if (!none_axes.empty()) {
         none_axes.pop_back();
       }
     }
+  }
   if (!none_axes.empty()) {
     paddle::Tensor new_out;
     {
@@ -955,7 +969,6 @@ static PyObject* tensor__getitem_index_not_tensor(TensorObject* self,
     }
     return ToPyObject(new_out);
   }
-  }
 
   // the index is a list
   if (list_select_flag) {

paddle/fluid/pybind/imperative.cc

@@ -1067,7 +1067,7 @@ void BindImperative(py::module *m_ptr) {
              }
 
              bool set_to_1d = FLAGS_set_to_1d;
-             if (!none_axes.empty()) {
+
              if (set_to_1d) {
                // NOTE(zoooo0820): When all axes are decreased, the output
                // will be 1-D with FLAGS_set_to_1d=True. In this case, one
@@ -1075,9 +1075,27 @@ void BindImperative(py::module *m_ptr) {
                // not correct.
                if (static_cast<int>(decrease_axis.size()) ==
                    tensor->dims().size()) {
+                 VLOG(0) << "Warning: In Tensor '__getitem__', if the number "
+                            "of scalar "
+                            "elements "
+                            "in the index is equal to the rank of the Tensor, "
+                            "the output "
+                            "should "
+                            "be 0-D. In order to be consistent with the "
+                            "behavior of previous "
+                            "versions, it will be processed to 1-D. But it is "
+                            "not correct and "
+                            "will be "
+                            "removed in release 2.6. "
+                            "If 1-D is still wanted, please modify the index "
+                            "element from "
+                            "scalar to slice "
+                            "(e.g. 'x[i]' => 'x[i:i+1]'). ";
+                 if (!none_axes.empty()) {
                    none_axes.pop_back();
                  }
                }
+             }
              if (!none_axes.empty()) {
                // Deal with cases that decrease_axes is not empty
                // For example:
@@ -1105,7 +1123,6 @@ void BindImperative(py::module *m_ptr) {
 
                return new_out;
              }
-             }
 
              // the index is a list
              if (list_select_flag) {

paddle/phi/kernels/funcs/slice_utils.h

@@ -208,18 +208,6 @@ inline DDim GetDecreasedDims(const DDim slice_dims,
     if (FLAGS_set_to_1d && new_shape.size() == 0) {
       // NOTE(zoooo0820): Hack procssing to 1-D, when axes decrease to 0-D in
       // slice. This will remove in release 2.6.
-      VLOG(0)
-          << "Warning:: In Tensor '__getitem__', if the number of scalar "
-             "elements "
-             "in the index is equal to the rank of the Tensor, the output "
-             "should "
-             "be 0-D. In order to be consistent with the behavior of previous "
-             "versions, it will be processed to 1-D. But it is not correct and "
-             "will be "
-             "removed in release 2.6. "
-             "If 1-D is still wanted, please modify the index element from "
-             "scalar to slice "
-             "(e.g. 'x[i]' => 'x[i:i+1]'). ";
       new_shape.push_back(1);
     }
     decreased_dims = phi::make_ddim(new_shape);

python/paddle/fluid/variable_index.py

@@ -17,6 +17,7 @@ import numpy as np
 from . import unique_name
 from . import core
 import paddle
+import warnings
 
 MAX_INTEGER = 2**31 - 1
 
@@ -579,6 +580,9 @@ def _getitem_impl_(var, item):
     # otherwise the output shape will be not correct.
     set_to_1d = paddle.get_flags('FLAGS_set_to_1d')['FLAGS_set_to_1d']
     if set_to_1d and len(decrease_axes) == len(var.shape):
+        warnings.warn(
+            "Warning: In Tensor '__getitem__', if the number of scalar elements in the index is equal to the rank of the Tensor, the output should be 0-D. In order to be consistent with the behavior of previous versions, it will be processed to 1-D. But it is not correct and will be removed in release 2.6. If 1-D is still wanted, please modify the index element from scalar to slice (e.g. 'x[i]' => 'x[i:i+1]')."
+        )
         none_axes = none_axes[1:]
 
     if len(none_axes) > 0: