Add support for global and nonlocal symbol renames (#5134)

## Summary

In #5074, we introduced an abstraction to support local symbol renames
("local" here refers to "within a module"). However, that abstraction
didn't support `global` and `nonlocal` symbols. This PR extends it to
those cases.

Broadly, there are considerations.

First, if we're renaming a symbol in a scope in which it is declared
`global` or `nonlocal`. For example, given:

```python
x = 1

def foo():
    global x
```

Then when renaming `x` in `foo`, we need to detect that it's `global`
and instead perform the rename starting from the module scope.

Second, when renaming a symbol, we need to determine the scopes in which
it is declared `global` or `nonlocal`. This is effectively the inverse
of the above: when renaming `x` in the module scope, we need to detect
that we should _also_ rename `x` in `foo`.

To support these cases, the renaming algorithm was adjusted as follows:

- When we start a rename in a scope, determine whether the symbol is
declared `global` or `nonlocal` by looking for a `global` or `nonlocal`
binding. If it is, start the rename in the defining scope. (This
requires storing the defining scope on the `nonlocal` binding, which is
new.)
- We then perform the rename in the defining scope.
- We then check whether the symbol was declared as `global` or
`nonlocal` in any scopes, and perform the rename in those scopes too.
(Thankfully, this doesn't need to be done recursively.)

Closes #5092.

## Test Plan

Added some additional snapshot tests.
This commit is contained in:
Charlie Marsh 2023-06-16 10:35:10 -04:00 committed by GitHub
parent b9754bd5c5
commit fd1dfc3bfa
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7 changed files with 305 additions and 81 deletions

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@ -10,6 +10,7 @@ use crate::context::ExecutionContext;
use crate::model::SemanticModel;
use crate::node::NodeId;
use crate::reference::ReferenceId;
use crate::ScopeId;
#[derive(Debug, Clone)]
pub struct Binding<'a> {
@ -336,7 +337,7 @@ pub enum BindingKind<'a> {
/// def foo():
/// nonlocal x
/// ```
Nonlocal,
Nonlocal(ScopeId),
/// A binding for a builtin, like `print` or `bool`.
Builtin,