Merge pull request RustPython#1232 from corona10/RustPythongh-1212

RustPythongh-1212: Fix scope_for_name to catch NameError properly

Author: windelbouwman

compiler/src/compile.rs

@@ -1912,7 +1912,9 @@ impl<O: OutputStream> Compiler<O> {
     fn lookup_name(&self, name: &str) -> &Symbol {
         // println!("Looking up {:?}", name);
         let scope = self.scope_stack.last().unwrap();
-        scope.lookup(name).unwrap()
+        scope.lookup(name).expect(
+            "The symbol must be present in the symbol table, even when it is undefined in python.",
+        )
     }
 
     // Low level helper functions:

compiler/src/symboltable.rs

@@ -244,13 +244,11 @@ impl SymbolTableBuilder {
             } => {
                 self.scan_expressions(decorator_list)?;
                 self.register_name(name, SymbolRole::Assigned)?;
-
-                self.enter_function(args)?;
-
-                self.scan_statements(body)?;
                 if let Some(expression) = returns {
                     self.scan_expression(expression)?;
                 }
+                self.enter_function(args)?;
+                self.scan_statements(body)?;
                 self.leave_scope();
             }
             ClassDef {

tests/snippets/function.py

@@ -1,4 +1,3 @@
-
 __name__ = "function"
 
 
@@ -72,3 +71,20 @@ def nested():
 
 
 f6()
+
+
+def f7():
+    try:
+        def t() -> void: # noqa: F821
+            pass
+    except NameError:
+        return True
+    return False
+
+assert f7()
+
+
+def f8() -> int:
+    return 10
+
+assert f8() == 10