Implemented the ability to del __dict__

hbina · hbina · commit d9640982a3de · 2025-03-08T19:18:41.000+08:00
This PR is based on the work by key262yek.

Signed-off-by: Hanif Ariffin &lt;hanif.ariffin.4326@gmail.com&gt;
diff --git a/vm/src/builtins/object.rs b/vm/src/builtins/object.rs
@@ -502,7 +502,7 @@ pub fn object_set_dict(
     vm: &VirtualMachine,
 ) -> PyResult<()> {
     obj.set_dict(dict)
-        .map_err(|_| vm.new_attribute_error("This object has no __dict__ to delete".to_owned()))
+        .ok_or_else(|| vm.new_type_error("cannot delete __dict__".to_owned()))
 }
 
 pub fn init(ctx: &Context) {
diff --git a/vm/src/builtins/type.rs b/vm/src/builtins/type.rs
@@ -1272,7 +1272,11 @@ fn subtype_get_dict(obj: PyObjectRef, vm: &VirtualMachine) -> PyResult {
     Ok(ret)
 }
 
-fn subtype_set_dict(obj: PyObjectRef, value: PyObjectRef, vm: &VirtualMachine) -> PyResult<()> {
+fn subtype_set_dict(
+    obj: PyObjectRef,
+    value: PySetterValue<PyObjectRef>,
+    vm: &VirtualMachine,
+) -> PyResult<()> {
     let cls = obj.class();
     match find_base_dict_descr(cls, vm) {
         Some(descr) => {
@@ -1285,10 +1289,11 @@ fn subtype_set_dict(obj: PyObjectRef, value: PyObjectRef, vm: &VirtualMachine) -
                         cls.name()
                     ))
                 })?;
-            descr_set(&descr, obj, PySetterValue::Assign(value), vm)
+            descr_set(&descr, obj, value, vm)
         }
         None => {
-            object::object_set_dict(obj, PySetterValue::Assign(value.try_into_value(vm)?), vm)?;
+            let dict = value.map(|s| s.try_into_value(vm)).transpose()?;
+            object::object_set_dict(obj, dict, vm)?;
             Ok(())
         }
     }
diff --git a/vm/src/function/getset.rs b/vm/src/function/getset.rs
@@ -36,10 +36,8 @@ where
 {
     #[inline]
     fn from_setter_value(vm: &VirtualMachine, obj: PySetterValue) -> PyResult<Self> {
-        match obj {
-            PySetterValue::Assign(obj) => T::try_from_object(vm, obj),
-            PySetterValue::Delete => T::try_from_object(vm, vm.ctx.none()),
-        }
+        let obj = obj.ok_or_else(|| vm.new_type_error("can't delete attribute".to_owned()))?;
+        T::try_from_object(vm, obj)
     }
 }
 
diff --git a/vm/src/object/core.rs b/vm/src/object/core.rs
@@ -712,28 +712,37 @@ impl PyObject {
 
     /// Set the dict field. Returns `Err(dict)` if this object does not have a dict field
     /// in the first place.
-    pub fn set_dict(&self, dict: PySetterValue<PyDictRef>) -> Result<(), PySetterValue<PyDictRef>> {
+    pub fn set_dict(&self, dict: PySetterValue<PyDictRef>) -> Option<()> {
+        // NOTE(hanif) - So far, this is the only error condition that I know of so we can use Option
+        // for now.
+        if self.payload_is::<crate::builtins::function::PyFunction>() {
+            return None;
+        }
+
         match (self.instance_dict(), dict) {
             (Some(d), PySetterValue::Assign(dict)) => {
                 d.set(dict);
-                Ok(())
             }
             (None, PySetterValue::Assign(dict)) => {
+                // self.0.dict = Some(InstanceDict::new(dict));
                 unsafe {
                     let ptr = self as *const _ as *mut PyObject;
                     (*ptr).0.dict = Some(InstanceDict::new(dict));
                 }
-                Ok(())
             }
             (Some(_), PySetterValue::Delete) => {
+                // self.0.dict = None;
                 unsafe {
                     let ptr = self as *const _ as *mut PyObject;
                     (*ptr).0.dict = None;
                 }
-                Ok(())
             }
-            (None, PySetterValue::Delete) => Err(PySetterValue::Delete),
-        }
+            (None, PySetterValue::Delete) => {
+                // NOTE(hanif) - noop?
+            }
+        };
+
+        Some(())
     }
 
     #[inline(always)]

Original file line number	Diff line number	Diff line change
`@@ -502,7 +502,7 @@ pub fn object_set_dict(`
`502`	`502`	`vm: &VirtualMachine,`
`503`	`503`	`) -> PyResult<()> {`
`504`	`504`	`obj.set_dict(dict)`
`505`		`- .map_err(\|_\| vm.new_attribute_error("This object has no __dict__ to delete".to_owned()))`
	`505`	`+ .ok_or_else(\|\| vm.new_type_error("cannot delete __dict__".to_owned()))`
`506`	`506`	`}`
`507`	`507`
`508`	`508`	`pub fn init(ctx: &Context) {`
Original file line number	Diff line number	Diff line change
`@@ -36,10 +36,8 @@ where`
`36`	`36`	`{`
`37`	`37`	`#[inline]`
`38`	`38`	`fn from_setter_value(vm: &VirtualMachine, obj: PySetterValue) -> PyResult<Self> {`
`39`		`- match obj {`
`40`		`- PySetterValue::Assign(obj) => T::try_from_object(vm, obj),`
`41`		`- PySetterValue::Delete => T::try_from_object(vm, vm.ctx.none()),`
`42`		`- }`
	`39`	`+ let obj = obj.ok_or_else(\|\| vm.new_type_error("can't delete attribute".to_owned()))?;`
	`40`	`+ T::try_from_object(vm, obj)`
`43`	`41`	`}`
`44`	`42`	`}`
`45`	`43`