Merge pull request RustPython#594 from skinny121/isinstance_2

cthulahoops · web-flow · commit 5d28f9bc36a0 · 2019-03-04T14:31:43.000Z
Only use real isinstance/issubclass for built-ins
diff --git a/vm/src/builtins.rs b/vm/src/builtins.rs
@@ -347,7 +347,7 @@ fn builtin_isinstance(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         required = [(obj, None), (typ, Some(vm.get_type()))]
     );
 
-    let isinstance = objtype::real_isinstance(vm, obj, typ)?;
+    let isinstance = vm.isinstance(obj, typ)?;
     Ok(vm.new_bool(isinstance))
 }
 
@@ -358,7 +358,7 @@ fn builtin_issubclass(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         required = [(subclass, Some(vm.get_type())), (cls, Some(vm.get_type()))]
     );
 
-    let issubclass = objtype::real_issubclass(vm, subclass, cls)?;
+    let issubclass = vm.issubclass(subclass, cls)?;
     Ok(vm.context().new_bool(issubclass))
 }
 
@@ -814,7 +814,7 @@ pub fn builtin_build_class_(vm: &mut VirtualMachine, mut args: PyFuncArgs) -> Py
     let mut metaclass = args.get_kwarg("metaclass", vm.get_type());
 
     for base in bases.clone() {
-        if objtype::real_issubclass(vm, &base.typ(), &metaclass)? {
+        if objtype::issubclass(&base.typ(), &metaclass) {
             metaclass = base.typ();
         } else if !objtype::issubclass(&metaclass, &base.typ()) {
             return Err(vm.new_type_error("metaclass conflict: the metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its bases".to_string()));
diff --git a/vm/src/macros.rs b/vm/src/macros.rs
@@ -19,7 +19,7 @@ macro_rules! type_check {
         if let Some(expected_type) = $arg_type {
             let arg = &$args.args[$arg_count];
 
-            if !$crate::obj::objtype::real_isinstance($vm, arg, &expected_type)? {
+            if !$crate::obj::objtype::isinstance(arg, &expected_type) {
                 let arg_typ = arg.typ();
                 let expected_type_name = $vm.to_pystr(&expected_type)?;
                 let actual_type = $vm.to_pystr(&arg_typ)?;
diff --git a/vm/src/obj/objsuper.rs b/vm/src/obj/objsuper.rs
@@ -72,9 +72,7 @@ fn super_init(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     };
 
     // Check obj type:
-    if !(objtype::real_isinstance(vm, &py_obj, &py_type)?
-        || objtype::real_issubclass(vm, &py_obj, &py_type)?)
-    {
+    if !(objtype::isinstance(&py_obj, &py_type) || objtype::issubclass(&py_obj, &py_type)) {
         return Err(vm.new_type_error(
             "super(type, obj): obj must be an instance or subtype of type".to_string(),
         ));
diff --git a/vm/src/obj/objtype.rs b/vm/src/obj/objtype.rs
@@ -1,4 +1,3 @@
-use super::objbool;
 use super::objdict;
 use super::objstr;
 use super::objtype; // Required for arg_check! to use isinstance
@@ -9,7 +8,6 @@ use crate::pyobject::{
 use crate::vm::VirtualMachine;
 use std::cell::RefCell;
 use std::collections::HashMap;
-use std::rc::Rc;
 
 /*
  * The magical type type
@@ -108,23 +106,6 @@ pub fn isinstance(obj: &PyObjectRef, cls: &PyObjectRef) -> bool {
     mro.into_iter().any(|c| c.is(&cls))
 }
 
-/// Determines if `obj` is an instance of `cls`, either directly, indirectly or virtually via the
-/// __instancecheck__ magic method.
-pub fn real_isinstance(
-    vm: &mut VirtualMachine,
-    obj: &PyObjectRef,
-    cls: &PyObjectRef,
-) -> PyResult<bool> {
-    // cpython first does an exact check on the type, although documentation doesn't state that
-    // https://github.com/python/cpython/blob/a24107b04c1277e3c1105f98aff5bfa3a98b33a0/Objects/abstract.c#L2408
-    if Rc::ptr_eq(&obj.typ(), cls) {
-        Ok(true)
-    } else {
-        let ret = vm.call_method(cls, "__instancecheck__", vec![obj.clone()])?;
-        objbool::boolval(vm, ret)
-    }
-}
-
 fn type_instance_check(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
@@ -142,17 +123,6 @@ pub fn issubclass(subclass: &PyObjectRef, cls: &PyObjectRef) -> bool {
     mro.into_iter().any(|c| c.is(&cls))
 }
 
-/// Determines if `subclass` is a subclass of `cls`, either directly, indirectly or virtually via
-/// the __subclasscheck__ magic method.
-pub fn real_issubclass(
-    vm: &mut VirtualMachine,
-    subclass: &PyObjectRef,
-    cls: &PyObjectRef,
-) -> PyResult<bool> {
-    let ret = vm.call_method(cls, "__subclasscheck__", vec![subclass.clone()])?;
-    objbool::boolval(vm, ret)
-}
-
 fn type_subclass_check(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(
         vm,
diff --git a/vm/src/pyobject.rs b/vm/src/pyobject.rs
@@ -922,7 +922,7 @@ impl PyFuncArgs {
     ) -> Result<Option<PyObjectRef>, PyObjectRef> {
         match self.get_optional_kwarg(key) {
             Some(kwarg) => {
-                if objtype::real_isinstance(vm, &kwarg, &ty)? {
+                if objtype::isinstance(&kwarg, &ty) {
                     Ok(Some(kwarg))
                 } else {
                     let expected_ty_name = vm.to_pystr(&ty)?;
@@ -1003,13 +1003,7 @@ where
             Ok(value) => Some(T::try_from_object(self.vm, value)),
             Err(err) => {
                 let stop_ex = self.vm.ctx.exceptions.stop_iteration.clone();
-                let stop = match objtype::real_isinstance(self.vm, &err, &stop_ex) {
-                    Ok(stop) => stop,
-                    Err(e) => {
-                        return Some(Err(e));
-                    }
-                };
-                if stop {
+                if objtype::isinstance(&err, &stop_ex) {
                     None
                 } else {
                     Some(Err(err))
diff --git a/vm/src/vm.rs b/vm/src/vm.rs
@@ -242,6 +242,26 @@ impl VirtualMachine {
         self.call_method(obj, "__repr__", vec![])
     }
 
+    /// Determines if `obj` is an instance of `cls`, either directly, indirectly or virtually via
+    /// the __instancecheck__ magic method.
+    pub fn isinstance(&mut self, obj: &PyObjectRef, cls: &PyObjectRef) -> PyResult<bool> {
+        // cpython first does an exact check on the type, although documentation doesn't state that
+        // https://github.com/python/cpython/blob/a24107b04c1277e3c1105f98aff5bfa3a98b33a0/Objects/abstract.c#L2408
+        if Rc::ptr_eq(&obj.typ(), cls) {
+            Ok(true)
+        } else {
+            let ret = self.call_method(cls, "__instancecheck__", vec![obj.clone()])?;
+            objbool::boolval(self, ret)
+        }
+    }
+
+    /// Determines if `subclass` is a subclass of `cls`, either directly, indirectly or virtually
+    /// via the __subclasscheck__ magic method.
+    pub fn issubclass(&mut self, subclass: &PyObjectRef, cls: &PyObjectRef) -> PyResult<bool> {
+        let ret = self.call_method(cls, "__subclasscheck__", vec![subclass.clone()])?;
+        objbool::boolval(self, ret)
+    }
+
     pub fn call_get_descriptor(&mut self, attr: PyObjectRef, obj: PyObjectRef) -> PyResult {
         let attr_class = attr.typ();
         if let Some(descriptor) = attr_class.get_attr("__get__") {
