[Model] Add user-configurable task for models that support both generation and embedding (#9424)

vllm/utils.py

@@ -1034,10 +1034,54 @@ def identity(value: T) -> T:
 F = TypeVar('F', bound=Callable[..., Any])
 
 
+def deprecate_args(
+    start_index: int,
+    is_deprecated: Union[bool, Callable[[], bool]] = True,
+    additional_message: Optional[str] = None,
+) -> Callable[[F], F]:
+
+    if not callable(is_deprecated):
+        is_deprecated = partial(identity, is_deprecated)
+
+    def wrapper(fn: F) -> F:
+
+        params = inspect.signature(fn).parameters
+        pos_types = (
+            inspect.Parameter.POSITIONAL_ONLY,
+            inspect.Parameter.POSITIONAL_OR_KEYWORD,
+        )
+        pos_kws = [
+            kw for kw, param in params.items() if param.kind in pos_types
+        ]
+
+        @wraps(fn)
+        def inner(*args, **kwargs):
+            if is_deprecated():
+                deprecated_args = pos_kws[start_index:len(args)]
+                if deprecated_args:
+                    msg = (
+                        f"The positional arguments {deprecated_args} are "
+                        "deprecated and will be removed in a future update.")
+                    if additional_message is not None:
+                        msg += f" {additional_message}"
+
+                    warnings.warn(
+                        DeprecationWarning(msg),
+                        stacklevel=3,  # The inner function takes up one level
+                    )
+
+            return fn(*args, **kwargs)
+
+        return inner  # type: ignore
+
+    return wrapper
+
+
 def deprecate_kwargs(
-        *kws: str,
-        is_deprecated: Union[bool, Callable[[], bool]] = True,
-        additional_message: Optional[str] = None) -> Callable[[F], F]:
+    *kws: str,
+    is_deprecated: Union[bool, Callable[[], bool]] = True,
+    additional_message: Optional[str] = None,
+) -> Callable[[F], F]:
     deprecated_kws = set(kws)
 
     if not callable(is_deprecated):