Skip to content

ast: fix identifier interning #8361

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
youknowone merged 2 commits into from
Jul 25, 2026
Merged

ast: fix identifier interning #8361

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
2b3e622
Fix AST identifier interning
widehyo1 Jul 25, 2026
dd94804
Apply PEP 8 import ordering
widehyo1 Jul 25, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 0 additions & 3 deletions Lib/test/test_ast/test_ast.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1331,7 +1331,6 @@ class MyNode(ast.AST):
self.assertEqual(repl.x, 0)
self.assertEqual(repl.y, y)

@unittest.expectedFailure # TODO: RUSTPYTHON; AssertionError: 'x' is not 'x'
def test_replace_ignore_known_custom_instance_fields(self):
node = ast.parse('x').body[0].value
node.extra = extra = object() # add instance 'extra' field
Expand Down Expand Up @@ -1401,7 +1400,6 @@ def test_replace_accept_missing_field_with_default(self):
self.assertIs(node2.returns, None)
self.assertEqual(node2.decorator_list, [])

@unittest.expectedFailure # TODO: RUSTPYTHON; AssertionError: "Name\.__replace__\ got\ an\ unexpected\ keyword\ argument\ 'extra'\." does not match "replace() does not support Name objects"
def test_replace_reject_known_custom_instance_fields_commits(self):
node = ast.parse('x').body[0].value
node.extra = extra = object() # add instance 'extra' field
Expand All @@ -1417,7 +1415,6 @@ def test_replace_reject_known_custom_instance_fields_commits(self):
self.assertIs(node.ctx, context)
self.assertIs(node.extra, extra)

@unittest.expectedFailure # TODO: RUSTPYTHON; AssertionError: "Name\.__replace__\ got\ an\ unexpected\ keyword\ argument\ 'unknown'\." does not match "replace() does not support Name objects"
def test_replace_reject_unknown_instance_fields(self):
node = ast.parse('x').body[0].value
context = node.ctx
Expand Down
3 changes: 2 additions & 1 deletion crates/vm/src/stdlib/_ast/expression.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1376,7 +1376,8 @@ impl Node for ast::ExprName {
.into_ref_with_type(vm, pyast::NodeExprName::static_type().to_owned())
.unwrap();
let dict = node.as_object().dict().unwrap();
dict.set_item("id", id.to_pyobject(vm), vm).unwrap();
dict.set_item("id", id.ast_to_object(vm, source_file), vm)
.unwrap();
dict.set_item("ctx", ctx.ast_to_object(vm, source_file), vm)
.unwrap();
node_add_location(&dict, range, vm, source_file);
Expand Down
2 changes: 1 addition & 1 deletion crates/vm/src/stdlib/_ast/statement.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -409,7 +409,7 @@ impl Node for ast::StmtFunctionDef {

let node = NodeAst.into_ref_with_type(vm, cls).unwrap();
let dict = node.as_object().dict().unwrap();
dict.set_item("name", vm.ctx.new_str(name.as_str()).to_pyobject(vm), vm)
dict.set_item("name", name.ast_to_object(vm, source_file), vm)
.unwrap();
dict.set_item("args", parameters.ast_to_object(vm, source_file), vm)
.unwrap();
Expand Down
20 changes: 20 additions & 0 deletions extra_tests/snippets/stdlib_ast.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,4 +1,5 @@
import ast
import copy

print(ast)

Expand Down Expand Up @@ -39,6 +40,25 @@ def foo():
assert i.names[0].asname is None


# Regression: parsed AST identifier fields are interned, matching CPython.
name_literal = "x"
name = ast.parse("x").body[0].value
assert name.id is name_literal

name.extra = object()
replacement = copy.replace(name)
assert replacement.id is name.id
assert replacement.ctx is name.ctx
assert not hasattr(replacement, "extra")

function_name = "f"
function = ast.parse("def f(): pass").body[0]
assert function.name is function_name

async_function = ast.parse("async def f(): pass").body[0]
assert async_function.name is function_name


# Regression test for issue #4862:
# A cyclic AST fed to compile() used to overflow the Rust stack and SIGSEGV.
# After the fix, the recursion guard in ast_from_object raises RecursionError,
Expand Down
Loading