Fix symbol table sub_table desync for non-simple annotation targets (#7300)

youknowone · web-flow · commit baba1f9447fd · 2026-03-02T16:47:16.000+09:00
* Fix symbol table sub_table desync for non-simple annotation targets

Non-simple annotations (subscript/attribute/parenthesized targets like
`a[0]: expr`) were scanned in the annotation scope during symbol table
analysis, creating sub_tables for any comprehensions. But codegen only
compiles simple name annotations into __annotate__, so those sub_tables
were never consumed. This caused subsequent simple annotations'
comprehension sub_tables to get the wrong index, resulting in
"the symbol 'X' must be present in the symbol table" errors.

Fix: skip entering annotation scope for non-simple annotations since
they are never compiled into __annotate__.

* Validate forbidden expressions in non-simple annotation targets

Fix cspell "desynchronize" warning and validate yield/await/named/async
comprehension expressions in non-simple annotations without creating
annotation scopes.

* Restore in_annotation flag before propagating error
diff --git a/Lib/test/test_type_annotations.py b/Lib/test/test_type_annotations.py
@@ -776,7 +776,6 @@ def test_non_name_annotations(self):
 
 class RegressionTests(unittest.TestCase):
     # gh-132479
-    @unittest.expectedFailure  # TODO: RUSTPYTHON; SyntaxError: the symbol 'unique_name_6' must be present in the symbol table
     def test_complex_comprehension_inlining(self):
         # Test that the various repro cases from the issue don't crash
         cases = [
diff --git a/crates/codegen/src/symboltable.rs b/crates/codegen/src/symboltable.rs
@@ -1053,6 +1053,11 @@ impl SymbolTableBuilder {
     /// Annotation and TypeParams scopes act as async barriers (always non-async).
     /// Comprehension scopes are transparent (inherit parent's async context).
     fn is_in_async_context(&self) -> bool {
+        // Annotations are evaluated in a non-async scope even when
+        // the enclosing function is async.
+        if self.in_annotation {
+            return false;
+        }
         for table in self.tables.iter().rev() {
             match table.typ {
                 CompilerScope::AsyncFunction => return true,
@@ -1462,7 +1467,22 @@ impl SymbolTableBuilder {
                         self.scan_expression(target, ExpressionContext::Store)?;
                     }
                 }
-                self.scan_annotation(annotation)?;
+                // Only scan annotation in annotation scope for simple name targets.
+                // Non-simple annotations (subscript, attribute, parenthesized) are
+                // never compiled into __annotate__, so scanning them would create
+                // sub_tables that cause mismatch in the annotation scope's sub_table index.
+                let is_simple_name = *simple && matches!(&**target, Expr::Name(_));
+                if is_simple_name {
+                    self.scan_annotation(annotation)?;
+                } else {
+                    // Still validate annotation for forbidden expressions
+                    // (yield, await, named) even for non-simple targets.
+                    let was_in_annotation = self.in_annotation;
+                    self.in_annotation = true;
+                    let result = self.scan_expression(annotation, ExpressionContext::Load);
+                    self.in_annotation = was_in_annotation;
+                    result?;
+                }
                 if let Some(value) = value {
                     self.scan_expression(value, ExpressionContext::Load)?;
                 }
