[RLlib] JAXPolicy prep PR #2 (move get_activation_fn (backward-compatibly), minor fixes and preparations). (#13091)

rllib/utils/framework.py

@@ -4,6 +4,7 @@ import os
 import sys
 from typing import Any, Optional
 
+from ray.rllib.utils.deprecation import deprecation_warning
 from ray.rllib.utils.typing import TensorStructType, TensorShape, TensorType
 
 logger = logging.getLogger(__name__)
@@ -252,7 +253,7 @@ def get_variable(value,
     return value
 
 
-# TODO: (sven) move to models/utils.py
+# Deprecated: Use rllib.models.utils::get_activation_fn instead.
 def get_activation_fn(name: Optional[str] = None, framework: str = "tf"):
     """Returns a framework specific activation function, given a name string.
 
@@ -268,6 +269,10 @@ def get_activation_fn(name: Optional[str] = None, framework: str = "tf"):
     Raises:
         ValueError: If name is an unknown activation function.
     """
+    deprecation_warning(
+        "rllib/utils/framework.py::get_activation_fn",
+        "rllib/models/utils.py::get_activation_fn",
+        error=False)
     if framework == "torch":
         if name in ["linear", None]:
             return None