[dy2stat_error] add revise suggestion for two error cases

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

@@ -143,6 +143,23 @@ def formated_message(self):
         return msg + '\n'.join(self.source_code) + '\n'
 
 
+class SuggestionDict(object):
+    def __init__(self):
+        # {(keywords): (suggestions)}
+        self.suggestion_dict = {
+            ('is not initialized.', 'Hint:', 'IsInitialized'):
+            ("Please ensure all your sublayers are inheritted from nn.Layer.",
+             "Please ensure there is no tensor created explicitly depended on external data, we suggest to register it as buffer tensor. See https://www.paddlepaddle.org.cn/documentation/docs/zh/guides/04_dygraph_to_static/export_model/principle_cn.html#parameters-buffers for details"
+             )
+        }
+
+    def keys(self):
+        return self.suggestion_dict.keys()
+
+    def __getitem__(self, key):
+        return self.suggestion_dict[key]
+
+
 class ErrorData(object):
     """
     Error data attached to an exception which is raised in un-transformed code.
@@ -155,6 +172,7 @@ def __init__(self, error_type, error_value, origin_traceback,
         self.origin_traceback = origin_traceback
         self.origin_info_map = origin_info_map
         self.in_runtime = False
+        self.suggestion_dict = SuggestionDict()
 
     def create_exception(self):
         message = self.create_message()
@@ -215,6 +233,22 @@ def create_message(self):
 
         return '\n'.join(message_lines)
 
+    def _create_revise_suggestion(self, bottom_error_message):
+        revise_suggestions = [
+            '', ' ' * BLANK_COUNT_BEFORE_FILE_STR + 'Revise suggestion: '
+        ]
+        for keywords in self.suggestion_dict.keys():
+            contain_keywords = [
+                True for i in keywords if i in ''.join(bottom_error_message)
+            ]
+            if len(contain_keywords) == len(
+                    keywords):  # all keywords should be in bottom_error_message
+                for suggestion in self.suggestion_dict[keywords]:
+                    suggestion_msg = ' ' * BLANK_COUNT_BEFORE_FILE_STR * 2 + '{}. {}'.format(
+                        str(len(revise_suggestions) - 1), suggestion)
+                    revise_suggestions.append(suggestion_msg)
+        return revise_suggestions if len(revise_suggestions) > 2 else []
+
     def _simplify_error_value(self):
         """
         Simplifies error value to improve readability if error is raised in runtime.
@@ -240,6 +274,7 @@ def _simplify_error_value(self):
         # use empty line to locate the bottom_error_message
         empty_line_idx = error_value_lines_strip.index('')
         bottom_error_message = error_value_lines[empty_line_idx + 1:]
+        revise_suggestion = self._create_revise_suggestion(bottom_error_message)
 
         filepath = ''
         error_from_user_code = []
@@ -269,6 +304,7 @@ def _simplify_error_value(self):
             error_frame.insert(0, traceback_frame.formated_message())
 
         error_frame.extend(bottom_error_message)
+        error_frame.extend(revise_suggestion)
         error_value_str = '\n'.join(error_frame)
         self.error_value = self.error_type(error_value_str)
 

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

@@ -474,11 +474,12 @@ def _check_params_all_inited(self, main_program):
                 if isinstance(var, framework.Parameter):
                     if name not in param_and_buffer_names_set:
                         raise ValueError(
-                            "\n\tWe don't support to define layer with parameters in the function "
-                            "decorated by `@declarative`.\n\tBecause that will re-defined parameters "
-                            "every time when you run the function.\n\t"
-                            "But we found parameter(%s) was created in the decorated function.\n\t"
-                            "Please define the layer with parameters in `__init__` function."
+                            "\n\tWe don't support to define layer with parameters in the function decorated by `@to_static`."
+                            "\n\tBut we found parameter(%s) was created in the decorated function."
+                            "\n"
+                            "\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)
 
     def _valid_vars(self, vars):

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

@@ -108,6 +108,31 @@ def func_error_in_runtime_with_empty_line(x):
     return x
 
 
+class SuggestionErrorTestNet(paddle.nn.Layer):
+    def __init__(self):
+        super(SuggestionErrorTestNet, self).__init__()
+        self.inner_net = SuggestionErrorTestNet2()
+
+    @paddle.jit.to_static
+    def forward(self, x):
+        return self.inner_net.forward(x)
+
+
+class SuggestionErrorTestNet2():
+    def __init__(self):
+        super(SuggestionErrorTestNet2, self).__init__()
+        self.w = paddle.to_tensor([2.])
+
+    def forward(self, x):
+        out = paddle.matmul(self.w, x)
+        return out
+
+
+def func_suggestion_error_in_runtime(x):
+    net = SuggestionErrorTestNet()
+    net(x)
+
+
 class TestFlags(unittest.TestCase):
     def setUp(self):
         self.reset_flags_to_default()
@@ -385,5 +410,39 @@ def test(self):
             func_decorated_by_other_2()
 
 
+class TestSuggestionErrorInRuntime(TestErrorBase):
+    def set_func(self):
+        self.func = func_suggestion_error_in_runtime
+
+    def set_input(self):
+        self.input = paddle.to_tensor([2.])
+
+    def set_exception_type(self):
+        self.exception_type = ValueError
+
+    def set_message(self):
+        self.expected_message = \
+            [
+                'File "{}", line 118, in forward'.format(self.filepath),
+                'return self.inner_net.forward(x)',
+                'File "{}", line 127, in forward'.format(self.filepath),
+                'def forward(self, x):',
+                'out = paddle.matmul(self.w, x)',
+                '<--- HERE',
+                'return out',
+                'Revise suggestion:',
+                'Please ensure all your sublayers are inheritted from nn.Layer.',
+                'Please ensure there is no tensor created explicitly depended on external data, we suggest to register it as buffer tensor. See'
+            ]
+
+    def set_func_call(self):
+        # NOTE: self.func(self.input) is the StaticLayer().__call__(self.input)
+        self.func_call = lambda: self.func(self.input)
+
+    def test_error(self):
+        for disable_new_error in [0, 1]:
+            self._test_raise_new_exception(disable_new_error)
+
+
 if __name__ == '__main__':
     unittest.main()