pytorch/docs/source/scripts
ydwu4 6abb8c382c [export] add kwargs support for export. (#105337)
Solving #105242.

During export, the exported function's signature changes multiple times. Suppose we'd like to export f as shown in following example:
```python
def f(arg1, arg2, kw1, kw2):
  pass

args = (arg1, arg2)
kwargs =  {"kw2":arg3, "kw1":arg4}

torch.export(f, args, kwargs)
```
The signature changes mutiple times during export process in the following order:
1. **gm_torch_level = dynamo.export(f, *args, \*\*kwargs)**. In this step, we turn all  kinds of parameters such as **postional_only**, **var_positioinal**, **kw_only**, and **var_kwargs** into **positional_or_kw**.It also preserves the positional and kword argument names in original function (i.e. f in this example) [here](https://github.com/pytorch/pytorch/blob/main/torch/_dynamo/export.py#L546C13-L546C27). The order of kwargs will be the **key order** of kwargs (after python 3.6, the order is the insertion of order of keys) instead of the original function signature and the order is baked into a _orig_args varaible of gm_torch_level's pytree info. So we'll have:
```python
def gm_torch_level(arg1, arg2, kw2, kw1)
```
Such difference is acceptable as it's transparent to users of export.

2. **gm_aot_export = aot_export_module(gm_torch_level, pos_or_kw_args)**. In this step, we need to turn kwargs into positional args in the order of how gm_torch_level expected, which is stored in _orig_args. The returned gm_aot_export has the graph signature of flat_args, in_spec = pytree.tree_flatten(pos_or_kw_args):
``` python
flat_args, _ = pytree.tree_flatten(pos_or_kw_args)
def gm_aot_export(*flat_args)
```

3. **exported_program(*args, \*\*kwargs)**. The epxorted artifact is exported_program, which is a wrapper over gm_aot_export and has the same calling convention as the original function "f". To do this, we need to 1. specialize the order of kwargs into pos_or_kw_args and 2. flatten the pos_or_kw_args into what gm_aot_export expected.  We can combine the two steps into one with :
```python
_, in_spec = pytree.tree_flatten((args, kwargs))

# Then during exported_program.__call__(*args, **kwargs)
flat_args  = fx_pytree.tree_flatten_spec((args, kwargs), in_spec)
```
, where kwargs is treated as a normal pytree whose keyorder is preserved in in_spec.

Implementation-wise, we treat _orig_args in dynamo exported graph module as single source of truth and kwags are ordered following it.

Test plan:
See added tests in test_export.py.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/105337
Approved by: https://github.com/angelayi, https://github.com/tugsbayasgalan
2023-07-20 19:53:08 +00:00
..
exportdb [export] add kwargs support for export. (#105337) 2023-07-20 19:53:08 +00:00
onnx [ONNX] Document ONNX diagnostics (#88371) 2022-11-16 19:21:46 +00:00
build_activation_images.py Fix LeakyReLU image (#78508) 2022-06-07 16:32:45 +00:00
build_opsets.py Rename Canonical Aten IR to Core Aten IR (#92904) 2023-01-25 05:12:23 +00:00
build_quantization_configs.py quant doc: improve rendered documentation for backend_config_dict 2022-05-18 11:46:07 +00:00