Fix init empty weights without accelerate (#37337)

* add the integration

* Update accelerate.py

* Update accelerate.py

* add find_tied_params as well

* Update accelerate.py

* add where copied from

* simplify

* add error

src/transformers/modeling_utils.py

@@ -57,6 +57,7 @@ from .configuration_utils import PretrainedConfig
 from .dynamic_module_utils import custom_object_save
 from .generation import CompileConfig, GenerationConfig, GenerationMixin
 from .integrations import PeftAdapterMixin, deepspeed_config, is_deepspeed_zero3_enabled
+from .integrations.accelerate import find_tied_parameters, init_empty_weights
 from .integrations.deepspeed import _load_state_dict_into_zero3_model, is_deepspeed_available
 from .integrations.flash_attention import flash_attention_forward
 from .integrations.flex_attention import flex_attention_forward
@@ -131,12 +132,11 @@ XLA_DOWNCAST_BF16 = os.environ.get("XLA_DOWNCAST_BF16", "0").upper()
 
 
 if is_accelerate_available():
-    from accelerate import dispatch_model, infer_auto_device_map, init_empty_weights
+    from accelerate import dispatch_model, infer_auto_device_map
     from accelerate.hooks import add_hook_to_module
     from accelerate.utils import (
         check_tied_parameters_on_same_device,
         extract_model_from_parallel,
-        find_tied_parameters,
         get_balanced_memory,
         get_max_memory,
         load_offloaded_weights,
@@ -4135,6 +4135,10 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMix
         if device_map is not None:
             if is_deepspeed_zero3_enabled():
                 raise ValueError("DeepSpeed Zero-3 is not compatible with passing a `device_map`.")
+            if not is_accelerate_available():
+                raise ValueError(
+                    "Using a `device_map` or `tp_plan` requires `accelerate`. You can install it with `pip install accelerate`"
+                )
 
         # handling bnb config from kwargs, remove after `load_in_{4/8}bit` deprecation.
         if load_in_4bit or load_in_8bit: