This patch addresses the renaming part of #133027, specifically, it
renames the following and adds documentation for relevant classes.
1. `VariableTracker.mutable_local` to `mutation_type`
2. `MatableLocal `to `ValueMutationNew`
3. `MutableSideEffects `to `ValueMutationExisting`
4. `MutableLocalSource` to `SourceType`
5. `MutableLocalSource.Local` to `New`
Note that (2), (3) and (5) are mainly to bring consistency between them
and `AttributeMutationNew`, `AttributeMutationExisting`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/139339
Approved by: https://github.com/jansel, https://github.com/mlazos, https://github.com/anijain2305
## The problem
In a typical debugger, `repr()` is used to display variables and not `str()`.
Several classes in Dynamo have a `__str__()` method that returns useful information and a `__repr__()` that does not. Having to call `str(x)` or `[str(i) for i in x]` in the debugger all the time is a chore.
`str()` should be ["informal, nicely printable"](https://docs.python.org/3/library/stdtypes.html#str) and `repr()` should ["attempt to return a string that would yield an object with the same value when passed to eval()](https://docs.python.org/3/library/functions.html#repr)".
## The solution
In the Python object model, if there is no `__str__` method, `__repr__` is used instead (but not the other way around).
So renaming `__str__` to `__repr__` in a few cases where no `__repr__` method exists now should not change observable behavior, and should make debugging easier.
The specific classes changed were all in `torch._dynamo.variables`:
* `builtin.BuiltinVariable`
* `constant.ConstantVariable`
* `constant.EnumVariable`
* `functions.UserMethodVariable`
* `lazy.LazyVariableTracker`
* `lazy.LazySymNodeFormatString`
* `misc.GetAttrVariable`
* `misc.NullVariable`
* `user_defined.UserDefinedObjectVariable`
Pull Request resolved: https://github.com/pytorch/pytorch/pull/136316
Approved by: https://github.com/XuehaiPan, https://github.com/jansel
## `VariableTracker::build()` hides the Builders
### The problem
In the current code, creating a `VariableTracker` involves choosing one of two `Builder` classes and either calling a method, or calling a constructor that creates an object that you immediately call, [like this](083c9149b7/torch/_dynamo/variables/functions.py (L761-L768)).
Variations on this code are repeated in many places.
More, the `Builder` classes have a lot of dependencies, so they have to be loaded late in the whole import process to avoid circular imports, so they end up being repeatedly imported at local scope.
### The solution
In this commit, the import from `builder` and the logic of choosing and calling the Builder class are hidden in a single static factory method, `VariableTracker.build()`, easier to reason about and to import.
This commit net lowers the total lines of code by over 150 lines by removing repetitive logic and unnecessary local imports.
**CHANGES:** Originally the name of the static method was `VariableTracker.create()` but a static method on a derived class, `LazyVariableTracker.create()` now exists with a different signature that's irreconcilable, so the new static method was renamed to `VariableTracker.build()`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/135714
Approved by: https://github.com/jansel
Fixes an issue where if the context arg is not provided, Dynamo would throw an arg mismatch error.
The skips are there because Dynamo would previously fall back to eager on those tests due to the arg mismatch error.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137809
Approved by: https://github.com/drisspg
See `test_inline_closure_returned_by_another_function_and_captures` and #136814 for more context.
In #90286, we introduced an optimization so that for captured cells that are unmodified during a Dynamo trace, `UserFunctionVariable` will represent them as variable of the cell's actual value, rather than a `NewCellVariable`.
Later on we introduced more mechanisms to model such cells across function calls (#104222), and across function calls where `NestedUserFunctionVariable::bind_args` need to look up further in the parent frames (#106491) to find these cells' values.
This patch removes `InlinedClosureVariable` in favor of a simpler modelling, which is also more consistent with what was introduced in #90286, i.e., just model these cells as their contents, in `symbolic_locals`.
This fixes#136814 because resolution of `InlinedClosureVariable` to the underlying cell content value happens in
`NestedUserFunctionVariable::bind_args`, which requires Dynamo to have the value in scope at the function call site (when Dynamo does inlining), but's not always the case (as the test case shows). However, if we model the cells in `symbolic_locals`, we never need such resolution, and the values are directly stored into the `NestedUserFunctionVariable::closure` upon the function creation, at which point Dynamo always has the cell value in `symbolic_locals` for look up.
Fixes#136814.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137510
Approved by: https://github.com/williamwen42
Moves `TransformGetItemToIndex` to a file where dynamo stores other traceable HOP concepts. (We don't trace through torch.* modules by default)
Tracing through the mode required fixing a bug in dynamo autograd function, which fixed a graph break, which caused the autograd test failures (skipping for now and will file an issue)
Previously those tests were in essence running in eager, because dynamo would fallback due to an arg mismatch error.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/137120
Approved by: https://github.com/yanboliang
ghstack dependencies: #137114, #137115, #137116, #137117
Changes:
1. Move `polyfill.py` -> `polyfills/__init__.py`. It can be used as `polyfill.xxx` -> `polyfills.xxx`.
2. Move submodule loading from `polyfills/__init__.py` to `polyfills/loader.py`.
Merge `polyfill.py` and `polyfills/` packages. Each polyfill module have its own namespace for better code organization.
The ultimate goal is make `polyfills/__init__.py` empty and all polyfill functions move to its own namespace.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133977
Approved by: https://github.com/jansel
Fixes the observed graph breaks in https://github.com/pytorch/pytorch/issues/121349 and https://github.com/pytorch/pytorch/issues/121350.
But there are still graph breaks since a random output is being used as a seed, e.g.
```python
import random
import torch
def fn(x):
seed = random.randint(0, 100)
rand = random.Random(seed)
return x + rand.randrange(10)
opt_fn = torch.compile(fn, backend="eager", fullgraph=True)
opt_fn(torch.ones(1))
```
fails with
```
torch._dynamo.exc.InternalTorchDynamoError: UnspecializedPythonVariable() is not a constant
```
when tracing the line
```
rand = random.Random(seed)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/133725
Approved by: https://github.com/jansel
