Add SymbolUsage::TypeParams (RustPython#5941)

Author: youknowone

Lib/test/test_typing.py

@@ -3888,8 +3888,6 @@ def test_pep695_generic_class_with_future_annotations(self):
         # should not have changed as a result of the get_type_hints() calls!
         self.assertEqual(ann_module695.__dict__, original_globals)
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_pep695_generic_class_with_future_annotations_and_local_shadowing(self):
         hints_for_B = get_type_hints(ann_module695.B)
         self.assertEqual(hints_for_B, {"x": int, "y": str, "z": bytes})
@@ -3935,8 +3933,6 @@ def test_pep_695_generic_method_with_future_annotations_name_clash_with_global_v
             set(ann_module695.D.generic_method_2.__type_params__)
         )
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_pep_695_generics_with_future_annotations_nested_in_function(self):
         results = ann_module695.nested()
 

compiler/codegen/src/compile.rs

@@ -638,7 +638,11 @@ impl Compiler<'_> {
                 cache = &mut info.cellvar_cache;
                 NameOpType::Deref
             } // TODO: is this right?
-              // SymbolScope::Unknown => NameOpType::Global,
+            SymbolScope::TypeParams => {
+                // Type parameters are always cell variables
+                cache = &mut info.cellvar_cache;
+                NameOpType::Deref
+            } // SymbolScope::Unknown => NameOpType::Global,
         };
 
         if NameUsage::Load == usage && name == "__debug__" {
@@ -1630,6 +1634,7 @@ impl Compiler<'_> {
             let vars = match symbol.scope {
                 SymbolScope::Free => &parent_code.freevar_cache,
                 SymbolScope::Cell => &parent_code.cellvar_cache,
+                SymbolScope::TypeParams => &parent_code.cellvar_cache,
                 _ if symbol.flags.contains(SymbolFlags::FREE_CLASS) => &parent_code.freevar_cache,
                 x => unreachable!(
                     "var {} in a {:?} should be free or cell but it's {:?}",

compiler/codegen/src/symboltable.rs

@@ -113,6 +113,7 @@ pub enum SymbolScope {
     GlobalImplicit,
     Free,
     Cell,
+    TypeParams,
 }
 
 bitflags! {
@@ -359,6 +360,10 @@ impl SymbolTableAnalyzer {
                 SymbolScope::Local | SymbolScope::Cell => {
                     // all is well
                 }
+                SymbolScope::TypeParams => {
+                    // Type parameters are always cell variables in their scope
+                    symbol.scope = SymbolScope::Cell;
+                }
                 SymbolScope::Unknown => {
                     // Try hard to figure out what the scope of this symbol is.
                     let scope = if symbol.is_bound() {
@@ -557,6 +562,7 @@ enum SymbolUsage {
     AnnotationParameter,
     AssignedNamedExprInComprehension,
     Iter,
+    TypeParam,
 }
 
 struct SymbolTableBuilder<'src> {
@@ -1267,6 +1273,9 @@ impl SymbolTableBuilder<'_> {
     }
 
     fn scan_type_params(&mut self, type_params: &TypeParams) -> SymbolTableResult {
+        // Register .type_params as a type parameter (automatically becomes cell variable)
+        self.register_name(".type_params", SymbolUsage::TypeParam, type_params.range)?;
+
         // First register all type parameters
         for type_param in &type_params.type_params {
             match type_param {
@@ -1276,7 +1285,7 @@ impl SymbolTableBuilder<'_> {
                     range: type_var_range,
                     ..
                 }) => {
-                    self.register_name(name.as_str(), SymbolUsage::Assigned, *type_var_range)?;
+                    self.register_name(name.as_str(), SymbolUsage::TypeParam, *type_var_range)?;
                     if let Some(binding) = bound {
                         self.scan_expression(binding, ExpressionContext::Load)?;
                     }
@@ -1286,14 +1295,14 @@ impl SymbolTableBuilder<'_> {
                     range: param_spec_range,
                     ..
                 }) => {
-                    self.register_name(name, SymbolUsage::Assigned, *param_spec_range)?;
+                    self.register_name(name, SymbolUsage::TypeParam, *param_spec_range)?;
                 }
                 TypeParam::TypeVarTuple(TypeParamTypeVarTuple {
                     name,
                     range: type_var_tuple_range,
                     ..
                 }) => {
-                    self.register_name(name, SymbolUsage::Assigned, *type_var_tuple_range)?;
+                    self.register_name(name, SymbolUsage::TypeParam, *type_var_tuple_range)?;
                 }
             }
         }
@@ -1544,6 +1553,11 @@ impl SymbolTableBuilder<'_> {
             SymbolUsage::Iter => {
                 flags.insert(SymbolFlags::ITER);
             }
+            SymbolUsage::TypeParam => {
+                // Type parameters are always cell variables in their scope
+                symbol.scope = SymbolScope::Cell;
+                flags.insert(SymbolFlags::ASSIGNED);
+            }
         }
 
         // and even more checking

vm/src/frame.rs

@@ -596,7 +596,11 @@ impl ExecutingFrame<'_> {
             }
             bytecode::Instruction::LoadClassDeref(i) => {
                 let i = i.get(arg) as usize;
-                let name = self.code.freevars[i - self.code.cellvars.len()];
+                let name = if i < self.code.cellvars.len() {
+                    self.code.cellvars[i]
+                } else {
+                    self.code.freevars[i - self.code.cellvars.len()]
+                };
                 let value = self.locals.mapping().subscript(name, vm).ok();
                 self.push_value(match value {
                     Some(v) => v,