Fix typechecks for casts to and from qualified cypclass

Cython/Compiler/ExprNodes.py

@@ -10921,6 +10921,8 @@ class TypecastNode(ExprNode):
                 if self.operand.type.is_ptr:
                     if not (self.operand.type.base_type.is_void or self.operand.type.base_type.is_struct):
                         error(self.pos, "Python objects cannot be cast from pointers of primitive types")
+                elif self.operand.type.is_qualified_cyp_class:
+                    error(self.pos, "Cannot cast '%s' to '%s'" % (self.operand.type, self.type))
                 else:
                     # Should this be an error?
                     warning(self.pos, "No conversion from %s to %s, python object pointer used." % (
@@ -10954,9 +10956,10 @@ class TypecastNode(ExprNode):
                 self.op_func_type = entry.type
             if self.type.is_cyp_class:
                 self.is_temp = self.overloaded
-                if self.type.is_qualified_cyp_class:
-                    if not self.type.assignable_from(self.operand.type):
-                        error(self.pos, "Cannot cast %s to %s" % (self.operand.type, self.type))
+            if self.type.is_cyp_class and self.operand.type.is_cyp_class:
+                if self.operand.type.is_qualified_cyp_class or self.type.is_qualified_cyp_class:
+                    if not (self.type.same_as(self.operand.type) or self.type.assignable_from(self.operand.type)):
+                        error(self.pos, "Cannot cast '%s' to '%s'" % (self.operand.type, self.type))
         if self.type.is_ptr and self.type.base_type.is_cfunction and self.type.base_type.nogil:
             op_type = self.operand.type
             if op_type.is_ptr:

tests/errors/cypclass_active_errors.pyx

@@ -19,6 +19,7 @@ cdef cypclass A activable:
 def test_aliasing():
     cdef active A active_a
 
+    # Aliasing from active
     cdef iso A iso_a
     iso_a = active_a
 
@@ -28,6 +29,17 @@ def test_aliasing():
     cdef A ref_a
     ref_a = active_a
 
+    # Aliasing to active
+    cdef active A active_b
+    active_b = A()
+
+    cdef active A active_c
+    active_c = consume A()
+
+    cdef active A active_d
+    active_d = <locked A> consume A()
+
+
 def test_calling():
     a = activate(consume A())
 
@@ -45,9 +57,41 @@ def test_calling():
     a.f_active(NULL, active_a)
 
 
+def test_typecast():
+    cdef active A active_a
+
+    # Casting from active
+    cdef iso A iso_a
+    iso_a = consume <iso A> active_a
+
+    cdef locked A locked_a
+    locked_a = <locked A> active_a
+
+    cdef A ref_a
+    ref_a = <A> active_a
+
+    # Casting to active
+    cdef active A active_b
+    active_b = <active A> A()
+
+    cdef active A active_c
+    active_c = <active A> <iso A> consume A()
+
+    cdef active A active_d
+    active_d = <active A> <locked A> consume A()
+
+
 _ERRORS = u'''
-23:12: Cannot assign type 'active A' to 'iso A'
-26:15: Cannot assign type 'active A' to 'locked A'
-29:12: Cannot assign type 'active A' to 'A'
-34:15: Cannot assign type 'A' to 'iso-> A'
+24:12: Cannot assign type 'active A' to 'iso A'
+27:15: Cannot assign type 'active A' to 'locked A'
+30:12: Cannot assign type 'active A' to 'A'
+34:16: Cannot assign type 'A' to 'active A'
+40:15: Cannot assign type 'locked A' to 'active A'
+46:15: Cannot assign type 'A' to 'iso-> A'
+65:20: Cannot cast 'active A' to 'iso A'
+68:15: Cannot cast 'active A' to 'locked A'
+71:12: Cannot cast 'active A' to 'A'
+75:15: Cannot cast 'A' to 'active A'
+78:15: Cannot cast 'iso A' to 'active A'
+81:15: Cannot cast 'locked A' to 'active A'
 '''

tests/errors/cypclass_iso_errors.pyx

@@ -9,7 +9,7 @@ def test_name_aliasing():
     cdef iso A iso_a
     iso_a = consume A()
 
-    # Aliasing non-consumed to iso
+    # Aliasing to iso
     cdef iso A iso_b
     iso_b = iso_a
 
@@ -75,6 +75,37 @@ def test_field_aliasing():
     c = o.bar(consume Field())
 
 
+def test_typecast():
+    cdef iso A iso_a
+    iso_a = consume A()
+
+    # Casting to iso
+    cdef iso A iso_b
+    iso_b = <iso A> A()
+
+    cdef iso A iso_c
+    iso_c = <iso A> activate(consume A())
+
+    cdef iso A iso_d
+    iso_d = <iso A> <object> A()
+
+    # Casting from iso
+    cdef active A active_a
+    active_a = <active A> iso_a
+
+    cdef A ref_a
+    ref_a = <A> iso_a
+
+    cdef object py_a
+    py_a = <object> iso_a
+
+    cdef iso A iso_e
+    iso_e = <iso A> iso_a
+
+    cdef iso A iso_f
+    iso_f = consume <iso A> iso_a
+
+
 _ERRORS = u'''
 14:12: Cannot assign type 'iso A' to 'iso A'
 17:13: Cannot assign type 'A' to 'iso A'
@@ -89,4 +120,13 @@ _ERRORS = u'''
 66:13: Cannot assign type 'iso-> Field' to 'iso-> Field'
 72:15: Cannot assign type 'Field' to 'iso-> Field'
 75:13: Cannot assign type 'iso-> Field' to 'iso-> Field'
+84:12: Cannot assign type 'iso A' to 'iso A'
+84:12: Cannot cast 'A' to 'iso A'
+87:12: Cannot assign type 'iso A' to 'iso A'
+87:12: Cannot cast 'active A' to 'iso A'
+90:12: Cannot assign type 'iso A' to 'iso A'
+94:15: Cannot cast 'iso A' to 'active A'
+97:12: Cannot cast 'iso A' to 'A'
+100:11: Cannot cast 'iso A' to 'Python object'
+103:12: Cannot assign type 'iso A' to 'iso A'
 '''