Merge pull request RustPython#3287 from Snowapril/fix-dir-incompatibility

Fix `dir` incompatibility with cpython

Author: DimitrisJim

vm/src/builtins/genericalias.rs

@@ -1,12 +1,24 @@
 use crate::{
-    builtins::{PyStr, PyTuple, PyTupleRef, PyTypeRef},
+    builtins::{PyList, PyStr, PyTuple, PyTupleRef, PyTypeRef},
     common::hash,
+    function::IntoPyObject,
     slots::{Hashable, SlotConstructor},
     IdProtocol, PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject,
     TypeProtocol, VirtualMachine,
 };
 use std::fmt;
 
+static ATTR_EXCEPTIONS: [&str; 8] = [
+    "__origin__",
+    "__args__",
+    "__parameters__",
+    "__mro_entries__",
+    "__reduce_ex__", // needed so we don't look up object.__reduce_ex__
+    "__reduce__",
+    "__copy__",
+    "__deepcopy__",
+];
+
 #[pyclass(module = "types", name = "GenericAlias")]
 pub struct PyGenericAlias {
     origin: PyTypeRef,
@@ -111,6 +123,17 @@ impl PyGenericAlias {
     fn origin(&self) -> PyObjectRef {
         self.origin.as_object().clone()
     }
+
+    #[pymethod(magic)]
+    fn dir(&self, vm: &VirtualMachine) -> PyResult<PyList> {
+        let dir = vm.dir(Some(self.origin()))?;
+        for exc in ATTR_EXCEPTIONS.iter() {
+            if !dir.contains((*exc).into_pyobject(vm), vm)? {
+                dir.append((*exc).into_pyobject(vm));
+            }
+        }
+        Ok(dir)
+    }
 }
 
 fn is_typevar(obj: PyObjectRef) -> bool {

vm/src/builtins/list.rs

@@ -266,7 +266,7 @@ impl PyList {
     }
 
     #[pymethod(magic)]
-    fn contains(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<bool> {
+    pub fn contains(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<bool> {
         // TODO: to_vec() cause copy which leads to cost O(N). It need to be improved.
         let elements = self.borrow_vec().to_vec();
         for elem in elements.iter() {

vm/src/stdlib/builtins.rs

@@ -191,15 +191,7 @@ mod builtins {
 
     #[pyfunction]
     fn dir(obj: OptionalArg<PyObjectRef>, vm: &VirtualMachine) -> PyResult<PyList> {
-        let seq = match obj {
-            OptionalArg::Present(obj) => vm
-                .get_special_method(obj, "__dir__")?
-                .map_err(|_obj| vm.new_type_error("object does not provide __dir__".to_owned()))?
-                .invoke((), vm)?,
-            OptionalArg::Missing => vm.call_method(vm.current_locals()?.as_object(), "keys", ())?,
-        };
-        let sorted = sorted(seq, Default::default(), vm)?;
-        Ok(sorted)
+        vm.dir(obj.into_option())
     }
 
     #[pyfunction]

vm/src/vm.rs

@@ -1195,6 +1195,20 @@ impl VirtualMachine {
             .invoke(args, self)
     }
 
+    pub fn dir(&self, obj: Option<PyObjectRef>) -> PyResult<PyList> {
+        let seq = match obj {
+            Some(obj) => self
+                .get_special_method(obj, "__dir__")?
+                .map_err(|_obj| self.new_type_error("object does not provide __dir__".to_owned()))?
+                .invoke((), self)?,
+            None => self.call_method(self.current_locals()?.as_object(), "keys", ())?,
+        };
+        let items = self.extract_elements(&seq)?;
+        let lst = PyList::from(items);
+        lst.sort(Default::default(), self)?;
+        Ok(lst)
+    }
+
     #[inline]
     pub(crate) fn get_special_method(
         &self,