small fixes to config

Summary:
- indicate location of OmegaConf.structured failures
- split the data gathering from enable_get_default_args to ease experimenting with it.
- comment fixes.
- nicer error when a_class_type has weird type.

Reviewed By: kjchalup

Differential Revision: D39434447

fbshipit-source-id: b80c7941547ca450e848038ef5be95b7ebbe8f3e

pytorch3d/implicitron/tools/config.py

@@ -287,6 +287,10 @@ class _Registry:
                 raise ValueError(
                     f"Cannot look up {base_class_wanted}. Cannot tell what it is."
                 )
+        if not isinstance(name, str):
+            raise ValueError(
+                f"Cannot look up a {type(name)} in the registry. Got {name}."
+            )
         result = self._mapping[base_class].get(name)
         if result is None:
             raise ValueError(f"{name} has not been registered.")
@@ -446,6 +450,11 @@ def _default_create_impl(
             setattr(self, name, None)
             return
 
+        if not isinstance(type_name, str):
+            raise ValueError(
+                f"A {type(type_name)} was received as the type of {name}."
+                + f" Perhaps this is from {name}{TYPE_SUFFIX}?"
+            )
         chosen_class = registry.get(type_, type_name)
         if self._known_implementations.get(type_name, chosen_class) is not chosen_class:
             # If this warning is raised, it means that a new definition of
@@ -514,7 +523,10 @@ def get_default_args(C, *, _do_not_process: Tuple[type, ...] = ()) -> DictConfig
         # because in practice get_default_args_field is used for
         # separate types than the outer type.
 
-        out: DictConfig = OmegaConf.structured(C)
+        try:
+            out: DictConfig = OmegaConf.structured(C)
+        except Exception as e:
+            raise ValueError(f"OmegaConf.structured({C}) failed") from e
         exclude = getattr(C, "_processed_members", ())
         with open_dict(out):
             for field in exclude:
@@ -534,7 +546,11 @@ def get_default_args(C, *, _do_not_process: Tuple[type, ...] = ()) -> DictConfig
             f"Cannot get args for {C}. Was enable_get_default_args forgotten?"
         )
 
-    return OmegaConf.structured(dataclass)
+    try:
+        out: DictConfig = OmegaConf.structured(dataclass)
+    except Exception as e:
+        raise ValueError(f"OmegaConf.structured failed for {dataclass_name}") from e
+    return out
 
 
 def _dataclass_name_for_function(C: Any) -> str:
@@ -546,22 +562,21 @@ def _dataclass_name_for_function(C: Any) -> str:
     return name
 
 
-def enable_get_default_args(C: Any, *, overwrite: bool = True) -> None:
+def _field_annotations_for_default_args(
+    C: Any,
+) -> List[Tuple[str, Any, dataclasses.Field]]:
     """
     If C is a function or a plain class with an __init__ function,
-    and you want get_default_args(C) to work, then add
-    `enable_get_default_args(C)` straight after the definition of C.
-    This makes a dataclass corresponding to the default arguments of C
-    and stores it in the same module as C.
+    return the fields which `enable_get_default_args(C)` will need
+    to make a dataclass with.
 
     Args:
         C: a function, or a class with an __init__ function. Must
             have types for all its defaulted args.
-        overwrite: whether to allow calling this a second time on
-            the same function.
+
+    Returns:
+        a list of fields for a dataclass.
     """
-    if not inspect.isfunction(C) and not inspect.isclass(C):
-        raise ValueError(f"Unexpected {C}")
 
     field_annotations = []
     for pname, defval in _params_iter(C):
@@ -572,8 +587,8 @@ def enable_get_default_args(C: Any, *, overwrite: bool = True) -> None:
 
         if defval.annotation == inspect._empty:
             raise ValueError(
-                "All arguments of the input callable have to be typed."
-                + f" Argument '{pname}' does not have a type annotation."
+                "All arguments of the input to enable_get_default_args have to"
+                f" be typed. Argument '{pname}' does not have a type annotation."
             )
 
         _, annotation = _resolve_optional(defval.annotation)
@@ -591,6 +606,28 @@ def enable_get_default_args(C: Any, *, overwrite: bool = True) -> None:
             field_ = dataclasses.field(default=default)
         field_annotations.append((pname, defval.annotation, field_))
 
+    return field_annotations
+
+
+def enable_get_default_args(C: Any, *, overwrite: bool = True) -> None:
+    """
+    If C is a function or a plain class with an __init__ function,
+    and you want get_default_args(C) to work, then add
+    `enable_get_default_args(C)` straight after the definition of C.
+    This makes a dataclass corresponding to the default arguments of C
+    and stores it in the same module as C.
+
+    Args:
+        C: a function, or a class with an __init__ function. Must
+            have types for all its defaulted args.
+        overwrite: whether to allow calling this a second time on
+            the same function.
+    """
+    if not inspect.isfunction(C) and not inspect.isclass(C):
+        raise ValueError(f"Unexpected {C}")
+
+    field_annotations = _field_annotations_for_default_args(C)
+
     name = _dataclass_name_for_function(C)
     module = sys.modules[C.__module__]
     if hasattr(module, name):
@@ -767,7 +804,7 @@ def expand_args_fields(
 
     Also adds the following class members, unannotated so that dataclass
     ignores them.
-        - _creation_functions: Tuple[str] of all the create_ functions,
+        - _creation_functions: Tuple[str, ...] of all the create_ functions,
             including those from base classes (not the create_x_impl ones).
         - _known_implementations: Dict[str, Type] containing the classes which
             have been found from the registry.
@@ -945,7 +982,7 @@ def _get_type_to_process(type_) -> Optional[Tuple[Type, _ProcessType]]:
             return underlying, _ProcessType.OPTIONAL_CONFIGURABLE
 
     if not isinstance(type_, type):
-        # e.g. any other Union or Tuple
+        # e.g. any other Union or Tuple. Or ClassVar.
         return
 
     if issubclass(type_, ReplaceableBase) and ReplaceableBase in type_.__bases__:

tests/implicitron/test_config.py

@@ -168,7 +168,7 @@ class TestConfig(unittest.TestCase):
         self.assertIn(Banana, all_fruit)
         self.assertIn(Pear, all_fruit)
         self.assertIn(LargePear, all_fruit)
-        self.assertEqual(set(registry.get_all(Pear)), {LargePear})
+        self.assertEqual(registry.get_all(Pear), [LargePear])
 
         @registry.register
         class Apple(Fruit):
@@ -178,7 +178,7 @@ class TestConfig(unittest.TestCase):
         class CrabApple(Apple):
             pass
 
-        self.assertEqual(set(registry.get_all(Apple)), {CrabApple})
+        self.assertEqual(registry.get_all(Apple), [CrabApple])
 
         self.assertIs(registry.get(Fruit, "CrabApple"), CrabApple)
 
@@ -601,6 +601,7 @@ class TestConfig(unittest.TestCase):
 
         for C_ in [C, C_fn, C_cl]:
             base = get_default_args(C_)
+            self.assertEqual(OmegaConf.to_yaml(base), "a: B1\n")
             self.assertEqual(base.a, A.B1)
             replaced = OmegaConf.merge(base, {"a": "B2"})
             self.assertEqual(replaced.a, A.B2)