let LazyCall support dataclasses

Summary: it was unsupported due to omegaconf

Reviewed By: zhanghang1989

Differential Revision: D30753898

fbshipit-source-id: d47b014bdc806023ebc95364359d8695865cd3c7

Author: ppwwyyxx

detectron2/config/lazy.py

@@ -9,6 +9,7 @@
 from collections import abc
 from contextlib import contextmanager
 from copy import deepcopy
+from dataclasses import is_dataclass
 from typing import List, Tuple, Union
 import cloudpickle
 import yaml
@@ -45,7 +46,14 @@ def __init__(self, target):
         self._target = target
 
     def __call__(self, **kwargs):
-        kwargs["_target_"] = self._target
+        if is_dataclass(self._target):
+            # omegaconf object cannot hold dataclass type
+            # https://github.com/omry/omegaconf/issues/784
+            target = _convert_target_to_string(self._target)
+        else:
+            target = self._target
+        kwargs["_target_"] = target
+
         return DictConfig(content=kwargs, flags={"allow_objects": True})
 
 

detectron2/evaluation/coco_evaluation.py

@@ -118,10 +118,12 @@ def __init__(
 
         self._metadata = MetadataCatalog.get(dataset_name)
         if not hasattr(self._metadata, "json_file"):
-            self._logger.info(
-                f"'{dataset_name}' is not registered by `register_coco_instances`."
-                " Therefore trying to convert it to COCO format ..."
-            )
+            if output_dir is None:
+                raise ValueError(
+                    "output_dir must be provided to COCOEvaluator "
+                    "for datasets not in COCO format."
+                )
+            self._logger.info(f"Trying to convert '{dataset_name}' to COCO format ...")
 
             cache_path = os.path.join(output_dir, f"{dataset_name}_coco_format.json")
             self._metadata.json_file = cache_path

dev/linter.sh

@@ -4,9 +4,9 @@
 # Run this script at project root by "./dev/linter.sh" before you commit
 
 {
-  black --version | grep -E "21.4b2" > /dev/null
+  black --version | grep -E "21\." > /dev/null
 } || {
-  echo "Linter requires 'black==21.4b2' !"
+  echo "Linter requires 'black==21.*' !"
   exit 1
 }
 

tests/config/test_instantiate_config.py

@@ -6,6 +6,7 @@
 import yaml
 from omegaconf import OmegaConf
 from omegaconf import __version__ as oc_version
+from dataclasses import dataclass
 
 from detectron2.config import instantiate, LazyCall as L
 from detectron2.layers import ShapeSpec
@@ -24,6 +25,12 @@ def __call__(self, call_arg):
         return call_arg + self.int_arg
 
 
+@dataclass
+class TestDataClass:
+    x: int
+    y: str
+
+
 @unittest.skipIf(OC_VERSION < (2, 1), "omegaconf version too old")
 class TestConstruction(unittest.TestCase):
     def test_basic_construct(self):
@@ -85,3 +92,9 @@ def test_instantiate_namedtuple(self):
     def test_bad_lazycall(self):
         with self.assertRaises(Exception):
             L(3)
+
+    def test_instantiate_dataclass(self):
+        a = L(TestDataClass)(x=1, y="s")
+        a = instantiate(a)
+        self.assertEqual(a.x, 1)
+        self.assertEqual(a.y, "s")