Merge pull request RustPython#3869 from tgsong827/stopiteraion

Fix define_exception! of PyStopIteration to set value of value attribute

Author: youknowone

Lib/test/test_yield_from.py

@@ -338,8 +338,6 @@ def g2():
             "Finishing g1",
         ])
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_value_attribute_of_StopIteration_exception(self):
         """
         Test 'value' attribute of StopIteration exception

vm/src/exceptions.rs

@@ -712,7 +712,7 @@ impl ExceptionZoo {
         extend_exception!(PyException, ctx, excs.exception_type);
 
         extend_exception!(PyStopIteration, ctx, excs.stop_iteration, {
-            "value" => ctx.new_readonly_getset("value", excs.stop_iteration, make_arg_getter(0)),
+            "value" => ctx.none(),
         });
         extend_exception!(PyStopAsyncIteration, ctx, excs.stop_async_iteration);
 
@@ -1098,8 +1098,15 @@ pub(super) mod types {
         PyStopIteration,
         PyException,
         stop_iteration,
-        "Signal the end from iterator.__next__()."
+        "Signal the end from iterator.__next__().",
+        base_exception_new,
+        stop_iteration_init
+    }
+    fn stop_iteration_init(zelf: PyObjectRef, args: FuncArgs, vm: &VirtualMachine) -> PyResult<()> {
+        zelf.set_attr("value", vm.unwrap_or_none(args.args.get(0).cloned()), vm)?;
+        Ok(())
     }
+
     define_exception! {
         PyStopAsyncIteration,
         PyException,

vm/src/vm/vm_new.rs

@@ -265,12 +265,21 @@ impl VirtualMachine {
     }
 
     pub fn new_stop_iteration(&self, value: Option<PyObjectRef>) -> PyBaseExceptionRef {
+        let dict = self.ctx.new_dict();
         let args = if let Some(value) = value {
+            // manually set `value` attribute like StopIteration.__init__
+            dict.set_item("value", value.clone(), self)
+                .expect("dict.__setitem__ never fails");
             vec![value]
         } else {
             Vec::new()
         };
-        self.new_exception(self.ctx.exceptions.stop_iteration.to_owned(), args)
+
+        PyRef::new_ref(
+            PyBaseException::new(args, self),
+            self.ctx.exceptions.stop_iteration.to_owned(),
+            Some(dict),
+        )
     }
 
     fn new_downcast_error(