Merge pull request #1447 from RustPython/coolreader18/type-attrs

windelbouwman · web-flow · commit 699450ddd735 · 2019-10-03T20:10:25.000+02:00
Fix properties on `type`
diff --git a/tests/snippets/types_snippet.py b/tests/snippets/types_snippet.py
@@ -43,6 +43,11 @@ class D(B, C): pass
 assert C.__subclasses__() == [D]
 assert D.__subclasses__() == []
 
+assert D.__bases__ == (B, C)
+assert A.__bases__ == (object,)
+assert B.__bases__ == (A,)
+
+
 del D
 
 try: # gc sweep is needed here for CPython...
diff --git a/vm/src/obj/objfunction.rs b/vm/src/obj/objfunction.rs
@@ -1,4 +1,4 @@
-use crate::function::{Args, KwArgs};
+use crate::function::PyFuncArgs;
 use crate::obj::objcode::PyCodeRef;
 use crate::obj::objdict::PyDictRef;
 use crate::obj::objtuple::PyTupleRef;
@@ -44,8 +44,8 @@ impl PyValue for PyFunction {
 }
 
 impl PyFunctionRef {
-    fn call(self, args: Args, kwargs: KwArgs, vm: &VirtualMachine) -> PyResult {
-        vm.invoke(&self.into_object(), (&args, &kwargs))
+    fn call(func: PyObjectRef, args: PyFuncArgs, vm: &VirtualMachine) -> PyResult {
+        vm.invoke(&func, args)
     }
 
     fn code(self, _vm: &VirtualMachine) -> PyCodeRef {
@@ -92,7 +92,8 @@ pub fn init(context: &PyContext) {
 
     let builtin_function_or_method_type = &context.types.builtin_function_or_method_type;
     extend_class!(context, builtin_function_or_method_type, {
-        "__get__" => context.new_rustfunc(bind_method)
+        "__get__" => context.new_rustfunc(bind_method),
+        "__call__" => context.new_rustfunc(PyFunctionRef::call),
     });
 }
 
diff --git a/vm/src/obj/objproperty.rs b/vm/src/obj/objproperty.rs
@@ -28,14 +28,13 @@ pub type PyReadOnlyPropertyRef = PyRef<PyReadOnlyProperty>;
 #[pyimpl]
 impl PyReadOnlyProperty {
     #[pymethod(name = "__get__")]
-    fn get(
-        zelf: PyRef<Self>,
-        obj: PyObjectRef,
-        _owner: OptionalArg<PyClassRef>,
-        vm: &VirtualMachine,
-    ) -> PyResult {
-        if obj.is(vm.ctx.none.as_object()) {
-            Ok(zelf.into_object())
+    fn get(zelf: PyRef<Self>, obj: PyObjectRef, cls: PyClassRef, vm: &VirtualMachine) -> PyResult {
+        if vm.is_none(&obj) {
+            if cls.is(&vm.ctx.types.type_type) {
+                vm.invoke(&zelf.getter, cls.into_object())
+            } else {
+                Ok(zelf.into_object())
+            }
         } else {
             vm.invoke(&zelf.getter, obj)
         }
diff --git a/vm/src/obj/objtype.rs b/vm/src/obj/objtype.rs
@@ -20,6 +20,7 @@ use super::objweakref::PyWeak;
 #[derive(Debug)]
 pub struct PyClass {
     pub name: String,
+    pub bases: Vec<PyClassRef>,
     pub mro: Vec<PyClassRef>,
     pub subclasses: RefCell<Vec<PyWeak>>,
     pub attributes: RefCell<PyAttributes>,
@@ -94,6 +95,11 @@ impl PyClassRef {
         Err(vm.new_attribute_error("read-only attribute".to_string()))
     }
 
+    fn bases(self, vm: &VirtualMachine) -> PyObjectRef {
+        vm.ctx
+            .new_tuple(self.bases.iter().map(|x| x.as_object().clone()).collect())
+    }
+
     fn dir(self, vm: &VirtualMachine) -> PyList {
         let attributes = get_attributes(self);
         let attributes: Vec<PyObjectRef> = attributes
@@ -241,6 +247,7 @@ pub fn init(ctx: &PyContext) {
                 .add_getter(PyClassRef::mro)
                 .add_setter(PyClassRef::set_mro)
                 .create(),
+        "__bases__" => ctx.new_property(PyClassRef::bases),
         "__name__" => ctx.new_property(PyClassRef::name),
         "__repr__" => ctx.new_rustfunc(PyClassRef::repr),
         "__qualname__" => ctx.new_property(PyClassRef::qualname),
@@ -290,8 +297,12 @@ fn type_new_slot(metatype: PyClassRef, args: PyFuncArgs, vm: &VirtualMachine) ->
 
     let (name, bases, dict): (PyStringRef, PyIterable<PyClassRef>, PyDictRef) = args.bind(vm)?;
 
-    let mut bases: Vec<PyClassRef> = bases.iter(vm)?.collect::<Result<Vec<_>, _>>()?;
-    bases.push(vm.ctx.object());
+    let bases: Vec<PyClassRef> = bases.iter(vm)?.collect::<Result<Vec<_>, _>>()?;
+    let bases = if bases.is_empty() {
+        vec![vm.ctx.object()]
+    } else {
+        bases
+    };
 
     let attributes = dict.to_attributes();
 
@@ -446,13 +457,10 @@ fn linearise_mro(mut bases: Vec<Vec<PyClassRef>>) -> Option<Vec<PyClassRef>> {
         if (&bases).iter().all(Vec::is_empty) {
             break;
         }
-        match take_next_base(bases) {
-            Some((head, new_bases)) => {
-                result.push(head);
-                bases = new_bases;
-            }
-            None => return None,
-        }
+        let (head, new_bases) = take_next_base(bases)?;
+
+        result.push(head);
+        bases = new_bases;
     }
     Some(result)
 }
@@ -468,6 +476,7 @@ pub fn new(
     let new_type = PyObject {
         payload: PyClass {
             name: String::from(name),
+            bases,
             mro,
             subclasses: RefCell::default(),
             attributes: RefCell::new(dict),
@@ -477,13 +486,16 @@ pub fn new(
         typ,
     }
     .into_ref();
-    for base in bases {
+
+    let new_type: PyClassRef = new_type.downcast().unwrap();
+
+    for base in &new_type.bases {
         base.subclasses
             .borrow_mut()
-            .push(PyWeak::downgrade(&new_type));
+            .push(PyWeak::downgrade(new_type.as_object()));
     }
 
-    Ok(new_type.downcast().unwrap())
+    Ok(new_type)
 }
 
 #[cfg(test)]
diff --git a/vm/src/types.rs b/vm/src/types.rs
@@ -232,6 +232,7 @@ fn init_type_hierarchy() -> (PyClassRef, PyClassRef) {
             dict: None,
             payload: PyClass {
                 name: String::from("object"),
+                bases: vec![],
                 mro: vec![],
                 subclasses: RefCell::default(),
                 attributes: RefCell::new(PyAttributes::new()),
@@ -245,6 +246,7 @@ fn init_type_hierarchy() -> (PyClassRef, PyClassRef) {
             dict: None,
             payload: PyClass {
                 name: String::from("type"),
+                bases: vec![object_type.clone().downcast().unwrap()],
                 mro: vec![object_type.clone().downcast().unwrap()],
                 subclasses: RefCell::default(),
                 attributes: RefCell::new(PyAttributes::new()),
