From aae512eb9e21709a85178be53aee7a280b53827e Mon Sep 17 00:00:00 2001
From: HAOCHENYE <21724054@zju.edu.cn>
Date: Thu, 6 Apr 2023 15:15:09 +0800
Subject: [PATCH] Refine debug message

---
 mmengine/registry/build_functions.py | 23 ++++++++++++-----------
 tests/test_registry/test_registry.py |  5 +++++
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/mmengine/registry/build_functions.py b/mmengine/registry/build_functions.py
index 9c28c571c0..254356fef9 100644
--- a/mmengine/registry/build_functions.py
+++ b/mmengine/registry/build_functions.py
@@ -121,17 +121,18 @@ def build_from_cfg(
             else:
                 obj = obj_cls(**args)  # type: ignore
 
-            # For some rare cases (e.g. obj_cls is a partial function), obj_cls
-            # doesn't have the following attributes. Use default value to
-            # prevent error
-            cls_name = getattr(obj_cls, '__name__', str(obj_cls))
-            cls_module = getattr(obj_cls, '__module__', 'unknown')
-            print_log(
-                f'An `{cls_name}` instance is built from '  # type: ignore # noqa: E501
-                'registry, its implementation can be found in '
-                f'{cls_module}',  # type: ignore
-                logger='current',
-                level=logging.DEBUG)
+            if (inspect.isclass(obj_cls) or inspect.isfunction(obj_cls)
+                    or inspect.ismethod(obj_cls)):
+                print_log(
+                    f'An `{obj_cls.__name__}` instance is built from '  # type: ignore # noqa: E501
+                    'registry, and its implementation can be found in '
+                    f'{obj_cls.__module__}',  # type: ignore
+                    logger='current',
+                    level=logging.DEBUG)
+            else:
+                print_log(
+                    'An instance is built from registry, and its constructor '
+                    f'is {obj_cls}')
             return obj
 
         except Exception as e:
diff --git a/tests/test_registry/test_registry.py b/tests/test_registry/test_registry.py
index 9ea4e4e22f..7deeb2e070 100644
--- a/tests/test_registry/test_registry.py
+++ b/tests/test_registry/test_registry.py
@@ -672,6 +672,11 @@ def forward(self, x):
     assert isinstance(model[1], ResNeXt)
     assert model[1].depth == 50 and model[1].stages == 3
 
+    NEW_FUNCTIONS = Registry('functions', scope='new')
+    NEW_FUNCTIONS.register_module(module=lambda x: x, name='lambda_function')
+    cfg = dict(type='lambda_function', x=1)
+    assert NEW_FUNCTIONS.build(cfg) == 1
+
     # test inherit `build_func` from parent
     NEW_MODELS = Registry('models', parent=BACKBONES, scope='new')
     assert NEW_MODELS.build_func is build_model_from_cfg