Remove use of __slots__ in classes.

The __slots__ attribute is not compatible with copy() operator.

Fixes #768.

compiler_gym/datasets/benchmark.py

@@ -85,8 +85,6 @@ class Benchmark:
 
     """
 
-    __slots__ = ["_proto", "_validation_callbacks", "_sources"]
-
     def __init__(
         self,
         proto: BenchmarkProto,

compiler_gym/envs/llvm/llvm_rewards.py

@@ -16,12 +16,6 @@ class CostFunctionReward(Reward):
     function.
     """
 
-    __slots__ = [
-        "cost_function",
-        "init_cost_function",
-        "previous_cost",
-    ]
-
     def __init__(self, cost_function: str, init_cost_function: str, **kwargs):
         """Constructor.
 
@@ -61,8 +55,6 @@ def update(
 class NormalizedReward(CostFunctionReward):
     """A cost function reward that is normalized to the initial value."""
 
-    __slots__ = ["cost_norm", "benchmark"]
-
     def __init__(self, **kwargs):
         """Constructor."""
         super().__init__(**kwargs)
@@ -100,8 +92,6 @@ class BaselineImprovementNormalizedReward(NormalizedReward):
     baseline approach.
     """
 
-    __slots__ = ["baseline_cost_function"]
-
     def __init__(self, baseline_cost_function: str, **kwargs):
         super().__init__(**kwargs)
         self.baseline_cost_function: str = baseline_cost_function

compiler_gym/spaces/reward.py

@@ -26,16 +26,6 @@ class Reward(Scalar):
     signals based on observation values computed by the backend service.
     """
 
-    __slots__ = [
-        "name",
-        "observation_spaces",
-        "default_value",
-        "default_negates_returns",
-        "success_threshold",
-        "deterministic",
-        "platform_dependent",
-    ]
-
     def __init__(
         self,
         name: str,

compiler_gym/spaces/scalar.py

@@ -14,8 +14,6 @@
 class Scalar(Space):
     """A scalar value."""
 
-    __slots__ = ["min", "max", "dtype"]
-
     def __init__(
         self,
         name: str,
@@ -35,10 +33,10 @@ def __init__(
 
         :param dtype: The type of this scalar.
         """
+        self.name = name
         self.min = min
         self.max = max
         self.dtype = dtype
-        self.name = name
 
     def sample(self):
         min = 0 if self.min is None else self.min

tests/spaces/scalar_test.py

@@ -3,6 +3,8 @@
 # This source code is licensed under the MIT license found in the
 # LICENSE file in the root directory of this source tree.
 """Unit tests for //compiler_gym/spaces:scalar."""
+from copy import copy, deepcopy
+
 from compiler_gym.spaces import Scalar
 from tests.test_main import main
 
@@ -67,5 +69,12 @@ def test_not_equal():
     assert scalar != "not_as_scalar"
 
 
+def test_deepcopy_regression_test():
+    """Test to reproduce github.com/facebookresearch/CompilerGym/issues/768."""
+    x = Scalar(name="foo")
+    copy(x)
+    deepcopy(x)
+
+
 if __name__ == "__main__":
     main()