[syntax-errors] Annotated name cannot be global (#20868)

## Summary

<!-- What's the purpose of the change? What does it do, and why? -->
This PR implements a new semantic syntax error where annotated name
can't be global
example
```
x: int = 1

def f():
    global x
    x: str = "foo"  # SyntaxError: annotated name 'x' can't be global
 ```

## Test Plan

<!-- How was it tested? -->
I have written tests as directed in #17412

---------

Signed-off-by: 11happy <soni5happy@gmail.com>
Signed-off-by: 11happy <bhuminjaysoni@gmail.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
This commit is contained in:
Bhuminjay Soni
2025-12-17 19:09:47 +05:30
committed by GitHub
parent 2a61fe2353
commit 52849a5e68
4 changed files with 128 additions and 1 deletions

View File

@@ -272,7 +272,9 @@ impl SemanticSyntaxChecker {
fn check_annotation<Ctx: SemanticSyntaxContext>(stmt: &ast::Stmt, ctx: &Ctx) {
match stmt {
Stmt::AnnAssign(ast::StmtAnnAssign { annotation, .. }) => {
Stmt::AnnAssign(ast::StmtAnnAssign {
target, annotation, ..
}) => {
if ctx.python_version() > PythonVersion::PY313 {
// test_ok valid_annotation_py313
// # parse_options: {"target-version": "3.13"}
@@ -297,6 +299,18 @@ impl SemanticSyntaxChecker {
};
visitor.visit_expr(annotation);
}
if let Expr::Name(ast::ExprName { id, .. }) = target.as_ref() {
if let Some(global_stmt) = ctx.global(id.as_str()) {
let global_start = global_stmt.start();
if !ctx.in_module_scope() || target.start() < global_start {
Self::add_error(
ctx,
SemanticSyntaxErrorKind::AnnotatedGlobal(id.to_string()),
target.range(),
);
}
}
}
}
Stmt::FunctionDef(ast::StmtFunctionDef {
type_params,