[Cherry-Pick][Dy2St]Support call backward() without params in dy2st (#49812) (#50144)

* [Dy2St]Support call backward() without params in dy2st (#49812)

* Support call backward() without params in dy2st

* format code

* format code

paddle/fluid/operators/select_output_op.cc

@@ -93,7 +93,8 @@ class SelectOutputInferShape : public framework::InferShapeBase {
   void operator()(framework::InferShapeContext *context) const override {
     OP_INOUT_CHECK(context->HasInput("X"), "Input", "X", "SelectOutput");
     OP_INOUT_CHECK(context->HasInput("Mask"), "Input", "Mask", "SelectOutput");
-    OP_INOUT_CHECK(context->HasOutputs("Out"), "Output", "Out", "SelectOutput");
+    OP_INOUT_CHECK(
+        context->HasOutputs("Out", true), "Output", "Out", "SelectOutput");
   }
 };
 

paddle/fluid/pybind/eager_legacy_custom_python_api.h

@@ -26,9 +26,9 @@ static PyObject *eager_api_run_program(PyObject *self,
                                        PyObject *kwargs) {
   PyThreadState *tstate = nullptr;
   try {
-    auto X = GetTensorListFromArgs("run_program", "X", args, 0, false);
+    auto X = GetTensorListFromArgs("run_program", "X", args, 0, true);
     auto Params = GetTensorListFromArgs("run_program", "Params", args, 1, true);
-    auto Out = GetTensorPtrListFromArgs("run_program", "Out", args, 2, false);
+    auto Out = GetTensorPtrListFromArgs("run_program", "Out", args, 2, true);
     auto OutScope =
         GetScopePtrListFromArgs("run_program", "OutScope", args, 3, false);
     auto DOut = GetTensorPtrListFromArgs("run_program", "DOut", args, 4, true);

python/paddle/fluid/dygraph/dygraph_to_static/partial_program.py

@@ -18,19 +18,32 @@ import six
 
 import paddle
 from paddle.fluid import framework, backward, core, program_guard
-from paddle.fluid.executor import _is_enable_standalone_executor, _is_dy2st_enable_standalone_executor
+from paddle.fluid.executor import (
+    _is_enable_standalone_executor,
+    _is_dy2st_enable_standalone_executor,
+)
 from paddle.fluid.dygraph import layers
 from paddle.fluid.dygraph.base import switch_to_static_graph
 from paddle.fluid.dygraph.dygraph_to_static import logging_utils
-from paddle.fluid.dygraph.dygraph_to_static.return_transformer import RETURN_NO_VALUE_MAGIC_NUM
+from paddle.fluid.dygraph.dygraph_to_static.return_transformer import (
+    RETURN_NO_VALUE_MAGIC_NUM,
+)
 from paddle.fluid.layers.utils import flatten
 from paddle.fluid.layers.utils import pack_sequence_as
 from paddle.fluid.layers.utils import _hash_with_id
 from paddle.fluid.compiler import BuildStrategy
 from paddle.fluid.framework import _apply_pass
-from paddle.fluid.contrib.mixed_precision.decorator import AutoMixedPrecisionLists
-from paddle.fluid.contrib.mixed_precision.fp16_utils import rewrite_program, cast_model_to_fp16
-from paddle.fluid.dygraph.amp.auto_cast import _in_amp_guard, _in_pure_fp16_guard
+from paddle.fluid.contrib.mixed_precision.decorator import (
+    AutoMixedPrecisionLists,
+)
+from paddle.fluid.contrib.mixed_precision.fp16_utils import (
+    rewrite_program,
+    cast_model_to_fp16,
+)
+from paddle.fluid.dygraph.amp.auto_cast import (
+    _in_amp_guard,
+    _in_pure_fp16_guard,
+)
 import paddle.compat as cpt
 from paddle import _C_ops, _legacy_C_ops
 
@@ -64,7 +77,8 @@ class NestSequence(object):
         var_ids = []
         for idx, var in enumerate(self.__input_list):
             if isinstance(
-                    var, (framework.Variable, core.VarBase, core.eager.Tensor)):
+                var, (framework.Variable, core.VarBase, core.eager.Tensor)
+            ):
                 var_ids.append(idx)
 
         return var_ids
@@ -77,15 +91,17 @@ class NestSequence(object):
             warning_types = set()
             for var in self.__input_list:
                 if not isinstance(
-                        var,
-                    (framework.Variable, core.VarBase, core.eager.Tensor)):
+                    var, (framework.Variable, core.VarBase, core.eager.Tensor)
+                ):
                     warning_types.add(type(var))
             if warning_types:
                 logging_utils.warn(
                     "Output of traced function contains non-tensor type values: {}. "
                     "Currently, We don't support to update them while training and will return "
-                    "what we first saw. Please try to return them as tensor.".
-                    format(list(warning_types)))
+                    "what we first saw. Please try to return them as tensor.".format(
+                        list(warning_types)
+                    )
+                )
 
     @property
     def var_ids(self):
@@ -139,12 +155,9 @@ class PartialProgramLayer:
         Layer: A Layer object that run all ops internally in static mode.
     """
 
-    def __init__(self,
-                 main_program,
-                 inputs,
-                 outputs,
-                 parameters=None,
-                 **kwargs):
+    def __init__(
+        self, main_program, inputs, outputs, parameters=None, **kwargs
+    ):
         super(PartialProgramLayer, self).__init__()
         self._inputs = NestSequence(inputs)
         self._outputs = NestSequence(outputs, need_check=True)
@@ -167,7 +180,8 @@ class PartialProgramLayer:
         # For AMP training
         self._amp_list = AutoMixedPrecisionLists(
             custom_white_list=custom_white_list,
-            custom_black_list=custom_black_list)
+            custom_black_list=custom_black_list,
+        )
 
         # program_id -> list(scope)
         self._scope_cache = {}
@@ -188,10 +202,6 @@ class PartialProgramLayer:
         else:
             return core.Scope()
 
-    @LazyInitialized
-    def __fake_vars(self):
-        return _create_fake_var()
-
     @LazyInitialized
     def _double_grads(self):
         return self._get_double_grads(self._origin_main_program)
@@ -203,7 +213,8 @@ class PartialProgramLayer:
             return self._origin_main_program.clone(for_test=is_infer_mode)
         else:
             train_program = self._append_backward_desc(
-                self._origin_main_program)
+                self._origin_main_program
+            )
             # Note: Only set grad type once after initializing train program. So we put it here.
             self._set_grad_type(self._params, train_program)
             return train_program
@@ -223,16 +234,18 @@ class PartialProgramLayer:
     @switch_to_static_graph
     def _create_pure_fp16_program(self, is_infer_mode=False):
         pure_fp16_program = self._origin_main_program.clone(
-            for_test=is_infer_mode)
+            for_test=is_infer_mode
+        )
         with program_guard(pure_fp16_program):
-            cast_model_to_fp16(pure_fp16_program,
-                               self._amp_list,
-                               use_fp16_guard=False)
+            cast_model_to_fp16(
+                pure_fp16_program, self._amp_list, use_fp16_guard=False
+            )
         if is_infer_mode:
             return pure_fp16_program
         else:
             train_pure_fp16_program = self._append_backward_desc(
-                pure_fp16_program)
+                pure_fp16_program
+            )
             self._set_grad_type(self._params, train_pure_fp16_program)
             return train_pure_fp16_program
 
@@ -240,23 +253,27 @@ class PartialProgramLayer:
     def _create_forward_backward_train_program(self):
         whole_program = self._create_program()
         forward_end_op_index = self._infer_program.desc.block(0).op_size()
-        return self._get_forward_backward_program_form(whole_program,
-                                                       forward_end_op_index)
+        return self._get_forward_backward_program_form(
+            whole_program, forward_end_op_index
+        )
 
     @switch_to_static_graph
     def _create_forward_backward_train_amp_program(self):
         whole_program = self._create_amp_program()
         forward_end_op_index = self._infer_amp_program.desc.block(0).op_size()
-        return self._get_forward_backward_program_form(whole_program,
-                                                       forward_end_op_index)
+        return self._get_forward_backward_program_form(
+            whole_program, forward_end_op_index
+        )
 
     @switch_to_static_graph
     def _create_forward_backward_train_pure_fp16_program(self):
         whole_program = self._create_pure_fp16_program()
         forward_end_op_index = self._infer_pure_fp16_program.desc.block(
-            0).op_size()
-        return self._get_forward_backward_program_form(whole_program,
-                                                       forward_end_op_index)
+            0
+        ).op_size()
+        return self._get_forward_backward_program_form(
+            whole_program, forward_end_op_index
+        )
 
     @LazyInitialized
     def _train_program(self):
@@ -352,8 +369,9 @@ class PartialProgramLayer:
     @LazyInitialized
     def _train_program_id(self):
         program_id = _hash_with_id(self._train_program, self)
-        core._set_cached_executor_build_strategy(program_id,
-                                                 self._build_strategy)
+        core._set_cached_executor_build_strategy(
+            program_id, self._build_strategy
+        )
         return program_id
 
     @LazyInitialized
@@ -363,8 +381,9 @@ class PartialProgramLayer:
     @LazyInitialized
     def _train_amp_program_id(self):
         program_id = _hash_with_id(self._train_amp_program, self)
-        core._set_cached_executor_build_strategy(program_id,
-                                                 self._build_strategy)
+        core._set_cached_executor_build_strategy(
+            program_id, self._build_strategy
+        )
         return program_id
 
     @LazyInitialized
@@ -374,8 +393,9 @@ class PartialProgramLayer:
     @LazyInitialized
     def _train_pure_fp16_program_id(self):
         program_id = _hash_with_id(self._train_pure_fp16_program, self)
-        core._set_cached_executor_build_strategy(program_id,
-                                                 self._build_strategy)
+        core._set_cached_executor_build_strategy(
+            program_id, self._build_strategy
+        )
         return program_id
 
     @LazyInitialized
@@ -411,8 +431,9 @@ class PartialProgramLayer:
 
         return main_program
 
-    def prepare_gradient_aggregation(self, start_idx, main_program,
-                                     target_program):
+    def prepare_gradient_aggregation(
+        self, start_idx, main_program, target_program
+    ):
         """
         Why we need add gradient aggregation operation ?
         In some cases, if non leaf nodes are used as output, gradient overwriting will occur, such as
@@ -431,7 +452,7 @@ class PartialProgramLayer:
             """
             if not isinstance(var, framework.Variable) or var.type not in [
                 core.VarDesc.VarType.LOD_TENSOR,
-                    core.VarDesc.VarType.SELECTED_ROWS
+                core.VarDesc.VarType.SELECTED_ROWS,
             ]:
                 return False
             if var.dtype not in [paddle.float32, paddle.float64]:
@@ -448,20 +469,28 @@ class PartialProgramLayer:
             new_grad_name = var.name + suffix + "@GRAD"
             finded_ops = list(
                 filter(
-                    lambda x: x[0] >= start_idx and any([
+                    lambda x: x[0] >= start_idx
+                    and any(
+                        [
                             out_arg == var_grad_name
                             for out_arg in x[1].output_arg_names
-                    ]), enumerate(target_program.block(0).ops)))
+                        ]
+                    ),
+                    enumerate(target_program.block(0).ops),
+                )
+            )
 
             # len(finded_ops) may equals zero when stop_gradient works.
             # len(finded_ops) may > 1, because we may have fill_constant op.
             if len(finded_ops) == 0:
                 return None
             # step1: create a new var named var.name@GRAD
-            target_program.block(0).create_var(name=new_grad_name,
+            target_program.block(0).create_var(
+                name=new_grad_name,
                 type=var.type,
                 dtype=var.dtype,
-                                               shape=var.shape)
+                shape=var.shape,
+            )
             # step2: rename the var.name@GRAD to var.name@GRAD@dy2static
             for idx, op in finded_ops:
                 op._rename_input(var_grad_name, new_grad_name)
@@ -472,11 +501,13 @@ class PartialProgramLayer:
                 finded_ops[-1][0] + 1,
                 type='sum',
                 inputs={'X': [var_grad_name, new_grad_name]},
-                outputs={"Out": var_grad_name})
+                outputs={"Out": var_grad_name},
+            )
             return None
 
         to_processed_vars = list(
-            filter(_need_aggregation, self._outputs.tolist()))
+            filter(_need_aggregation, self._outputs.tolist())
+        )
         for _var in to_processed_vars:
             _insert_aggregation_ops_for_var(target_program, _var)
 
@@ -489,11 +520,12 @@ class PartialProgramLayer:
             if isinstance(out, framework.Variable):
                 targets.append(program.global_block().var(out.name))
 
-        if targets and self._params:
+        if targets:
             backward.gradients(targets=targets, inputs=[])
 
-        start_idx = len(
-            main_program.block(0).ops) + 2 * len(self._outputs.tolist())
+        start_idx = len(main_program.block(0).ops) + 2 * len(
+            self._outputs.tolist()
+        )
 
         self.prepare_gradient_aggregation(start_idx, main_program, program)
 
@@ -512,7 +544,10 @@ class PartialProgramLayer:
             found_param = False
             for block in program.blocks:
                 for op in block.ops:
-                    if param.name in op.input_arg_names or param.name in op.output_arg_names:
+                    if (
+                        param.name in op.input_arg_names
+                        or param.name in op.output_arg_names
+                    ):
                         required_params.append(param)
                         found_param = True
                         break
@@ -529,15 +564,21 @@ class PartialProgramLayer:
                     var_desc = block.vars[name].desc
                     var_base = None
                     if not framework._in_eager_mode_:
-                        var_base = core.VarBase(var_desc.dtype(),
+                        var_base = core.VarBase(
+                            var_desc.dtype(),
                             var_desc.shape(),
                             var_desc.name(),
-                                                var_desc.type(), False)
+                            var_desc.type(),
+                            False,
+                        )
                     else:
-                        var_base = core.eager.Tensor(var_desc.dtype(),
+                        var_base = core.eager.Tensor(
+                            var_desc.dtype(),
                             var_desc.shape(),
                             var_desc.name(),
-                                                     var_desc.type(), False)
+                            var_desc.type(),
+                            False,
+                        )
                     double_grads.append(var_base)
         return self._valid_vars(double_grads)
 
@@ -557,36 +598,62 @@ class PartialProgramLayer:
 
         attrs = [
             'global_block',
-            self.program.desc.block(0), 'start_op_index', 0, 'end_op_index',
-            self._get_end_op_index(), 'is_test', not self.training,
-            'program_id', self.program_id
+            self.program.desc.block(0),
+            'start_op_index',
+            0,
+            'end_op_index',
+            self._get_end_op_index(),
+            'is_test',
+            not self.training,
+            'program_id',
+            self.program_id,
         ]
         if self._cuda_graph_capture_mode:
             attrs.extend(
-                ('cuda_graph_capture_mode', self._cuda_graph_capture_mode,
-                 'cuda_graph_pool_id', self._cuda_graph_pool_id))
-
-        use_interpretorcore = _is_enable_standalone_executor(
-        ) and _is_dy2st_enable_standalone_executor()
+                (
+                    'cuda_graph_capture_mode',
+                    self._cuda_graph_capture_mode,
+                    'cuda_graph_pool_id',
+                    self._cuda_graph_pool_id,
+                )
+            )
+
+        use_interpretorcore = (
+            _is_enable_standalone_executor()
+            and _is_dy2st_enable_standalone_executor()
+        )
         attrs.extend(('use_interpretorcore', use_interpretorcore))
         if use_interpretorcore:
             attrs.extend(
-                ('forward_global_block', self.forward_program.desc.block(0),
-                 'backward_global_block', self.backward_program.desc.block(0)))
+                (
+                    'forward_global_block',
+                    self.forward_program.desc.block(0),
+                    'backward_global_block',
+                    self.backward_program.desc.block(0),
+                )
+            )
 
             _legacy_C_ops.run_program(
-                self._valid_vars(in_vars), self._valid_vars(self._params),
+                self._valid_vars(in_vars),
+                self._valid_vars(self._params),
                 self._valid_vars(out_vars),
-                self._create_scope_vec(program_id=self.program_id,
-                                       use_scope_cache=True),
-                self._double_grads, self._cuda_graph_vec, *attrs)
+                self._create_scope_vec(
+                    program_id=self.program_id, use_scope_cache=True
+                ),
+                self._double_grads,
+                self._cuda_graph_vec,
+                *attrs
+            )
         else:
-            _legacy_C_ops.run_program(self._valid_vars(in_vars),
+            _legacy_C_ops.run_program(
+                self._valid_vars(in_vars),
                 self._valid_vars(self._params),
                 self._valid_vars(out_vars),
                 self._create_scope_vec(),
-                                      self._double_grads, self._cuda_graph_vec,
-                                      *attrs)
+                self._double_grads,
+                self._cuda_graph_vec,
+                *attrs
+            )
         restored_nest_out = self._restore_out(out_vars)
         return self._remove_no_value(restored_nest_out)
 
@@ -594,9 +661,11 @@ class PartialProgramLayer:
         if _in_pure_fp16_guard():
             for i, var in enumerate(in_vars):
                 name = var.name
-                if (self.program.global_block().has_var(name)
+                if (
+                    self.program.global_block().has_var(name)
                     and self.program.global_block().var(name).dtype
-                        == paddle.float16):
+                    == paddle.float16
+                ):
                     in_vars[i] = var.astype('float16')
                     in_vars[i].name = name
 
@@ -627,25 +696,32 @@ class PartialProgramLayer:
             return self._infer_program
 
     @switch_to_static_graph
-    def _get_forward_backward_program_form(self, whole_program,
-                                           forward_end_op_index):
+    def _get_forward_backward_program_form(
+        self, whole_program, forward_end_op_index
+    ):
         forward_builded_program = add_build_strategy_for(
-            whole_program, 0, forward_end_op_index, self._build_strategy)
+            whole_program, 0, forward_end_op_index, self._build_strategy
+        )
         backward_start_op_index = forward_end_op_index + 2 * len(
-            self._outputs.var_ids)
+            self._outputs.var_ids
+        )
         backward_end_op_index = whole_program.desc.block(0).op_size()
         backward_builded_program = add_build_strategy_for(
-            whole_program, backward_start_op_index, backward_end_op_index,
-            self._build_strategy)
-        self._apply_inplace_pass(forward_builded_program,
-                                 backward_builded_program)
+            whole_program,
+            backward_start_op_index,
+            backward_end_op_index,
+            self._build_strategy,
+        )
+        self._apply_inplace_pass(
+            forward_builded_program, backward_builded_program
+        )
         return [forward_builded_program, backward_builded_program]
 
     def _apply_inplace_pass(self, forward_program, backward_program):
         attr_types = {
             "use_cuda": "bool",
             "mem_opt_skip_vars": "list[str]",
-            "for_partial_block": "bool"
+            "for_partial_block": "bool",
         }
         empty_startup_program = paddle.static.Program()
         use_cuda = True if core.is_compiled_with_cuda() else False
@@ -667,22 +743,33 @@ class PartialProgramLayer:
                 forward_mem_opt_skip_vars.append(var.desc.name())
                 backward_mem_opt_skip_vars.append(var.desc.name())
         for var_name in core.parse_safe_eager_deletion_skip_vars(
-                backward_program.desc):
+            backward_program.desc
+        ):
             forward_mem_opt_skip_vars.append(var_name)
         attrs = {
             "use_cuda": use_cuda,
             "mem_opt_skip_vars": forward_mem_opt_skip_vars,
-            "for_partial_block": True
+            "for_partial_block": True,
         }
-        _apply_pass(forward_program, empty_startup_program,
-                    "buffer_shared_inplace_pass", attrs, attr_types)
+        _apply_pass(
+            forward_program,
+            empty_startup_program,
+            "buffer_shared_inplace_pass",
+            attrs,
+            attr_types,
+        )
         attrs = {
             "use_cuda": use_cuda,
             "mem_opt_skip_vars": backward_mem_opt_skip_vars,
-            "for_partial_block": True
+            "for_partial_block": True,
         }
-        _apply_pass(backward_program, empty_startup_program,
-                    "buffer_shared_inplace_pass", attrs, attr_types)
+        _apply_pass(
+            backward_program,
+            empty_startup_program,
+            "buffer_shared_inplace_pass",
+            attrs,
+            attr_types,
+        )
 
     def _prepare(self, inputs):
         """
@@ -698,23 +785,28 @@ class PartialProgramLayer:
             if isinstance(value, np.ndarray):
                 var = None
                 if not framework._in_eager_mode_:
-                    var = core.VarBase(value=value,
+                    var = core.VarBase(
+                        value=value,
                         name=self._inputs[i].desc.name(),
                         persistable=False,
                         place=expected_place,
-                                       zero_copy=True)
+                        zero_copy=True,
+                    )
                 else:
-                    var = core.eager.Tensor(value=value,
+                    var = core.eager.Tensor(
+                        value=value,
                         name=self._inputs[i].desc.name(),
                         persistable=False,
                         place=expected_place,
-                                            zero_copy=True)
+                        zero_copy=True,
+                    )
             elif isinstance(value, (core.VarBase, core.eager.Tensor)):
                 # NOTE(Aurelius84): If var is on CPUPlace, it will be transformed multi times
                 # into CUDAPlace when it's as input of multi Ops. so we move it in advance
                 # to avoid this problem.
                 if value.stop_gradient and not value.place._equals(
-                        expected_place):
+                    expected_place
+                ):
                     var = value._copy_to(expected_place, False)
                     var.stop_gradient = True
                 else:
@@ -737,12 +829,21 @@ class PartialProgramLayer:
                 return out_varbase_map[var_desc.name()]
 
             if not framework._in_eager_mode_:
-                var_base = core.VarBase(var_desc.dtype(), var_desc.shape(),
-                                        var_desc.name(), var_desc.type(), False)
+                var_base = core.VarBase(
+                    var_desc.dtype(),
+                    var_desc.shape(),
+                    var_desc.name(),
+                    var_desc.type(),
+                    False,
+                )
             else:
-                var_base = core.eager.Tensor(var_desc.dtype(), var_desc.shape(),
-                                             var_desc.name(), var_desc.type(),
-                                             False)
+                var_base = core.eager.Tensor(
+                    var_desc.dtype(),
+                    var_desc.shape(),
+                    var_desc.name(),
+                    var_desc.type(),
+                    False,
+                )
             var_base.stop_gradient = var.stop_gradient
             out_varbase_map[var_desc.name()] = var_base
             return var_base
@@ -755,20 +856,30 @@ class PartialProgramLayer:
     def _create_scope_vec(self, program_id=None, use_scope_cache=False):
         # Hold forward variables
         tmp_scope_vec = None
-        inner_scope = self._get_scope(program_id=program_id,
-                                      use_scope_cache=use_scope_cache)
+        inner_scope = self._get_scope(
+            program_id=program_id, use_scope_cache=use_scope_cache
+        )
         if not framework._in_eager_mode_:
-            tmp_scope_vec = core.VarBase(core.VarDesc.VarType.FP32, [],
+            tmp_scope_vec = core.VarBase(
+                core.VarDesc.VarType.FP32,
+                [],
                 "program_out_scope",
-                                         core.VarDesc.VarType.STEP_SCOPES, True)
+                core.VarDesc.VarType.STEP_SCOPES,
+                True,
+            )
             tmp_scope_vec.value().set_scope(inner_scope)
         else:
             tmp_scope_vec = [inner_scope]
         return tmp_scope_vec
 
     def _create_cuda_graph_vec(self):
-        var = core.VarBase(core.VarDesc.VarType.FP32, [], "cuda_graph",
-                           core.VarDesc.VarType.RAW, True)
+        var = core.VarBase(
+            core.VarDesc.VarType.FP32,
+            [],
+            "cuda_graph",
+            core.VarDesc.VarType.RAW,
+            True,
+        )
         var.stop_gradient = True
         return var
 
@@ -791,8 +902,9 @@ class PartialProgramLayer:
         return main_program.clone(for_test=True)
 
     def _is_no_value(self, var):
-        if isinstance(var,
-                      (core.VarBase, core.eager.Tensor)) and var.shape == [1]:
+        if isinstance(var, (core.VarBase, core.eager.Tensor)) and var.shape == [
+            1
+        ]:
             # NOTE: .numpy() will insert MemcpySync operation, it hits performance.
             if var.numpy()[0] == RETURN_NO_VALUE_MAGIC_NUM:
                 return True
@@ -808,13 +920,14 @@ class PartialProgramLayer:
             return out_vars
         elif isinstance(out_vars, (tuple, list)):
             if isinstance(out_vars, tuple):
-                res = tuple(var for var in out_vars
-                            if not self._is_no_value(var))
+                res = tuple(
+                    var for var in out_vars if not self._is_no_value(var)
+                )
             else:
                 # isinstance(out_vars, list)
                 res = [var for var in out_vars if not self._is_no_value(var)]
 
-            has_removed = (len(out_vars) > len(res))
+            has_removed = len(out_vars) > len(res)
             # len(out_vars) > len(res) means we have removed var. This is
             # preventing out_vars is empty or just one element at the beginning
             if len(res) == 0 and has_removed:
@@ -835,7 +948,8 @@ class PartialProgramLayer:
         for param in params:
             grad_name = param.name + core.grad_var_suffix()
             grad_var = train_program.desc.block(0).find_var(
-                cpt.to_bytes(grad_name))
+                cpt.to_bytes(grad_name)
+            )
             # NOTE: cannot find var desc maybe no problem, such as in batch_norm
             if grad_var is None:
                 continue
@@ -864,15 +978,18 @@ class PartialProgramLayer:
         if not isinstance(self._params, (list, tuple)):
             raise TypeError(
                 "Type of self._params in PartialProgramLayer should be list or tuple, but received %s."
-                % type(self._params))
+                % type(self._params)
+            )
 
         param_and_buffer_names_set = set()
         for i, var in enumerate(self._params):
             # self._params constains parameters and buffers with persistable=True.
             if not isinstance(var, (core.VarBase, core.eager.Tensor)):
                 raise TypeError(
-                    'Type of self._params[{}] in PartialProgramLayer should be Parameter or Variable, but received {}.'
-                    .format(i, type(var)))
+                    'Type of self._params[{}] in PartialProgramLayer should be Parameter or Variable, but received {}.'.format(
+                        i, type(var)
+                    )
+                )
             param_and_buffer_names_set.add(var.name)
 
         for block in main_program.blocks:
@@ -886,15 +1003,11 @@ class PartialProgramLayer:
                             "\n\tRevise suggestion: "
                             "\n\t\t1. Please ensure all your sublayers are inheritted from nn.Layer."
                             "\n\t\t2. Please use nn.ParameterList and nn.LayerList as container instead of using a native Python container such as List"
-                            % name)
+                            % name
+                        )
 
     def _valid_vars(self, vars):
-        """
-        Note: run_program_op.InferShape requires `X`/'Out' not be null.
-        But it's common in dy2static, fake varBase is created to handle the
-        problem.
-        """
-        return vars if vars else self.__fake_vars
+        return vars if vars else None
 
 
 def _create_fake_var():
@@ -903,13 +1016,23 @@ def _create_fake_var():
     """
     if not framework._in_eager_mode_:
         return [
-            core.VarBase(core.VarDesc.VarType.FP32, [], "Fake_var",
-                         core.VarDesc.VarType.RAW, False)
+            core.VarBase(
+                core.VarDesc.VarType.FP32,
+                [],
+                "Fake_var",
+                core.VarDesc.VarType.RAW,
+                False,
+            )
         ]
     else:
         return [
-            core.eager.Tensor(core.VarDesc.VarType.FP32, [], "Fake_var",
-                              core.VarDesc.VarType.RAW, False)
+            core.eager.Tensor(
+                core.VarDesc.VarType.FP32,
+                [],
+                "Fake_var",
+                core.VarDesc.VarType.RAW,
+                False,
+            )
         ]
 
 
@@ -918,23 +1041,27 @@ def partial_program_from(concrete_program):
     if inputs and isinstance(inputs[0], layers.Layer):
         inputs = inputs[1:]
 
-    return PartialProgramLayer(concrete_program.main_program, inputs,
+    return PartialProgramLayer(
+        concrete_program.main_program,
+        inputs,
         concrete_program.outputs,
         concrete_program.parameters,
-                               **concrete_program.kwargs)
+        **concrete_program.kwargs
+    )
 
 
 @switch_to_static_graph
-def add_build_strategy_for(program,
-                           start_op_index,
-                           end_op_index,
-                           build_strategy=None):
-    if (start_op_index < end_op_index):
+def add_build_strategy_for(
+    program, start_op_index, end_op_index, build_strategy=None
+):
+    if start_op_index < end_op_index:
         compiled_program = paddle.static.CompiledProgram(
             core.Graph(program.desc, start_op_index, end_op_index),
-            build_strategy=build_strategy)
-        compiled_program._compile(core.Scope(),
-                                  framework._current_expected_place())
+            build_strategy=build_strategy,
+        )
+        compiled_program._compile(
+            core.Scope(), framework._current_expected_place()
+        )
         ir_graph = framework.IrGraph(compiled_program._graph)
         builded_program = ir_graph.to_program()
         if hasattr(compiled_program._program, 'lr_sheduler'):

python/paddle/fluid/tests/unittests/dygraph_to_static/test_backward_without_params.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.
+
+import unittest
+
+import numpy as np
+
+import paddle
+
+
+class Net(paddle.nn.Layer):
+    def __init__(self):
+        super(Net, self).__init__()
+
+    @paddle.jit.to_static
+    def forward(self, x):
+        out = x + 1
+        return out
+
+
+class TestBackwardWithoutParams(unittest.TestCase):
+    def test_run(self):
+        net = Net()
+
+        x = paddle.ones([2, 2])
+        x.stop_gradient = False
+        out = net(x)
+        loss = paddle.mean(out)
+        loss.backward()
+        np.testing.assert_equal(x.grad.numpy(), np.full(x.shape, 0.25))
+
+
+if __name__ == '__main__':
+    unittest.main()

python/paddle/fluid/tests/unittests/dygraph_to_static/test_for_enumerate.py

@@ -292,7 +292,6 @@ def for_tuple_as_enumerate_value(x_array):
 
 # 20. test for function in a class
 class ForwardContainsForLayer(paddle.nn.Layer):
-
     def __init__(self):
         super(ForwardContainsForLayer, self).__init__()
         self.high = 5
@@ -328,8 +327,8 @@ def for_original_tuple():
 
 # 23. for zip error
 @paddle.jit.to_static(
-    input_spec=[InputSpec(shape=[None, 10]),
-                InputSpec(shape=[None, 10])])
+    input_spec=[InputSpec(shape=[None, 10]), InputSpec(shape=[None, 10])]
+)
 def for_zip_error(x, y):
     for i, j in zip(x, y):
         a = i + j
@@ -338,8 +337,8 @@ def for_zip_error(x, y):
 
 # 24. for zip
 @paddle.jit.to_static(
-    input_spec=[InputSpec(shape=[2, 10]),
-                InputSpec(shape=[2, 10])])
+    input_spec=[InputSpec(shape=[2, 10]), InputSpec(shape=[2, 10])]
+)
 def for_zip(x, y):
     for i, j in zip(x, y):
         a = i + j
@@ -347,10 +346,12 @@ def for_zip(x, y):
 
 
 class TestTransformBase(unittest.TestCase):
-
     def setUp(self):
-        self.place = fluid.CUDAPlace(
-            0) if fluid.is_compiled_with_cuda() else fluid.CPUPlace()
+        self.place = (
+            fluid.CUDAPlace(0)
+            if fluid.is_compiled_with_cuda()
+            else fluid.CPUPlace()
+        )
         self.set_input()
         self.set_test_func()
 
@@ -359,7 +360,8 @@ class TestTransformBase(unittest.TestCase):
 
     def set_test_func(self):
         raise NotImplementedError(
-            "For Enumerate test should implement set_test_func")
+            "For Enumerate test should implement set_test_func"
+        )
 
     def _run(self, to_static):
         program_translator.enable(to_static)
@@ -374,22 +376,21 @@ class TestTransformBase(unittest.TestCase):
 
 
 class TestTransform(TestTransformBase):
-
     def transformed_result_compare(self):
         dy_outs = self.get_dygraph_output()
         if not isinstance(dy_outs, (tuple, list)):
-            dy_outs = (dy_outs, )
+            dy_outs = (dy_outs,)
 
+        self.dygraph_func.eval()
         st_outs = self.get_static_output()
         if not isinstance(st_outs, (tuple, list)):
-            st_outs = (st_outs, )
+            st_outs = (st_outs,)
 
         for x, y in zip(dy_outs, st_outs):
             np.testing.assert_allclose(x.numpy(), y.numpy(), rtol=1e-05)
 
 
 class TestTransformForOriginalList(TestTransform):
-
     def _run(self, to_static):
         program_translator.enable(to_static)
         with fluid.dygraph.guard():
@@ -397,7 +398,6 @@ class TestTransformForOriginalList(TestTransform):
 
 
 class TestTransformError(TestTransformBase):
-
     def transformed_error(self, etype):
         with self.assertRaises(etype):
             dy_out = self.get_dygraph_output()
@@ -405,7 +405,6 @@ class TestTransformError(TestTransformBase):
 
 
 class TestForInRange(TestTransform):
-
     def set_input(self):
         self.input = np.array([5])
 
@@ -417,7 +416,6 @@ class TestForInRange(TestTransform):
 
 
 class TestForIterList(TestTransform):
-
     def set_test_func(self):
         self.dygraph_func = for_iter_list
 
@@ -426,19 +424,16 @@ class TestForIterList(TestTransform):
 
 
 class TestForEnumerateSimple(TestForIterList):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_list
 
 
 class TestForInRangeWithBreak(TestForInRange):
-
     def set_test_func(self):
         self.dygraph_func = for_in_range_with_break
 
 
 class TestForIterVarNumpy(TestTransform):
-
     def set_input(self):
         self.input = np.array([1, 2, 3, 4, 5])
 
@@ -450,103 +445,86 @@ class TestForIterVarNumpy(TestTransform):
 
 
 class TestForEnumerateVarNumpy(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy
 
 
 class TestForEnumerateVarNumpyWithStart(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy_with_start
 
 
 class TestForEnumerateVarNumpyWithBreak(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy_with_break
 
 
 class TestForEnumerateVarNumpyWithContinue(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy_with_continue
 
 
 class TestForEnumerateVarNumpyWithStartAndBreak(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy_with_start_break
 
 
 class TestForEnumerateVarNumpyWithStartAndContinue(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_numpy_with_start_continue
 
 
 class TestForIterVar(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_iter_var
 
 
 class TestForIterVarIdx(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_iter_var_idx
 
 
 class TestForEnumerateVar(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var
 
 
 class TestForEnumerateVarWithNestedRange(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_with_nested_range
 
 
 class TestForIterVarList(TestForInRange):
-
     def set_test_func(self):
         self.dygraph_func = for_iter_var_list
 
 
 class TestForEnumerateVarList(TestForInRange):
-
     def set_test_func(self):
         self.dygraph_func = for_enumerate_var_list
 
 
 class TestForTupleAsIterVar(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_tuple_as_iter_var
 
 
 class TestForTupleAsEnumerateIter(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_tuple_as_enumerate_iter
 
 
 class TestForTupleAsEnumerateValue(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = for_tuple_as_enumerate_value
 
 
 class TestForwardContainsForLayer(TestForIterVarNumpy):
-
     def set_test_func(self):
         self.dygraph_func = ForwardContainsForLayer()
 
 
 class TestForOriginalList(TestTransformForOriginalList):
-
     def set_test_func(self):
         self.dygraph_func = for_original_list
 
@@ -555,7 +533,6 @@ class TestForOriginalList(TestTransformForOriginalList):
 
 
 class TestForOriginalTuple(TestTransformForOriginalList):
-
     def set_test_func(self):
         self.dygraph_func = for_original_tuple
 
@@ -564,7 +541,6 @@ class TestForOriginalTuple(TestTransformForOriginalList):
 
 
 class TestForZip(unittest.TestCase):
-
     def setUp(self):
         self.temp_dir = tempfile.TemporaryDirectory()