Disallow method overloading on cypclass qualifiers

Cython/Compiler/PyrexTypes.py

@@ -3219,6 +3219,8 @@ class CFuncType(CType):
             return 0
         if self.has_varargs != other_type.has_varargs:
             return 0
+        if self.self_qualifier != other_type.self_qualifier:
+            return 0
         self_minargs = len(self.args) - self.optional_arg_count
         if self_minargs > len(other_type.args):
             return 0
@@ -3255,6 +3257,8 @@ class CFuncType(CType):
                 return 0
         if self.has_varargs != other_type.has_varargs:
             return 0
+        if self.self_qualifier != other_type.self_qualifier:
+            return 0
         return 1
 
     def compatible_signature_with(self, other_type, as_cmethod = 0, skip_args=0, skip_return=0):
@@ -3313,6 +3317,29 @@ class CFuncType(CType):
                     return 0
         if self.has_varargs != other_type.has_varargs:
             return 0
+        if self.self_qualifier != other_type.self_qualifier:
+            return 0
+        if self.optional_arg_count != other_type.optional_arg_count:
+            return 0
+        return 1
+
+    def same_args_without_qualifiers_with(self, other_type, as_cmethod = 0):
+        return self.same_args_without_qualifiers_with_resolved_type(other_type.resolve(), as_cmethod)
+
+    def same_args_without_qualifiers_with_resolved_type(self, other_type, as_cmethod = 0):
+        if other_type is error_type:
+            return 1
+        if not other_type.is_cfunction:
+            return 0
+        nargs = len(self.args)
+        if nargs != len(other_type.args):
+            return 0
+        for i in range(as_cmethod, nargs):
+            if not same_without_qualifier(self.args[i].type, other_type.args[i].type):
+                if not self.args[i].type.same_as(other_type.args[i].type):
+                    return 0
+        if self.has_varargs != other_type.has_varargs:
+            return 0
         if self.optional_arg_count != other_type.optional_arg_count:
             return 0
         return 1
@@ -3334,6 +3361,8 @@ class CFuncType(CType):
                     return 0
         if self.has_varargs != other_type.has_varargs:
             return 0
+        if self.self_qualifier != other_type.self_qualifier:
+            return 0
         if self.optional_arg_count != other_type.optional_arg_count:
             return 0
         return 1
@@ -3357,6 +3386,8 @@ class CFuncType(CType):
                 return 0
         if self.has_varargs != other_type.has_varargs:
             return 0
+        if self.self_qualifier != other_type.self_qualifier:
+            return 0
         if self.optional_arg_count != other_type.optional_arg_count:
             return 0
         return 1
@@ -3396,7 +3427,7 @@ class CFuncType(CType):
 
     def same_as_resolved_type(self, other_type, as_cmethod=False):
         return self.same_c_signature_as_resolved_type(other_type, as_cmethod=as_cmethod) \
-            and self.nogil == other_type.nogil
+            and self.nogil == other_type.nogil and self.self_qualifier == other_type.self_qualifier
 
     def pointer_assignable_from_resolved_type(self, rhs_type):
         # Accept compatible exception/nogil declarations for the RHS.
@@ -5913,6 +5944,15 @@ def ptr_to_same_without_cv(type1, type2):
         return same_type(type1, type2)
     return 0
 
+def same_without_qualifier(type1, type2):
+    if type1.is_cyp_class and type2.is_cyp_class:
+        if type1.is_qualified_cyp_class:
+            type1 = type1.qual_base_type
+        if type2.is_qualified_cyp_class:
+            type2 = type2.qual_base_type
+        return same_type(type1, type2)
+    return 0
+
 def typecast(to_type, from_type, expr_code):
     #  Return expr_code cast to a C type which can be
     #  assigned to to_type, assuming its existing C type

Cython/Compiler/Symtab.py

@@ -543,7 +543,13 @@ class Scope(object):
                     for index, alt_entry in enumerate(old_entry.all_alternatives()):
                         alt_type = alt_entry.type
 
-                        if type.compatible_arguments_with(alt_type):
+                        if type.self_qualifier != alt_type.self_qualifier:
+                            error(pos, "Cannot overload on 'self' qualifier")
+                            if alt_entry.pos is not None:
+                                error(alt_entry.pos, "Conflicting method is defined here")
+                            break
+
+                        elif type.compatible_arguments_with(alt_type):
                             cpp_override_allowed = False
 
                             # allow default constructor or __alloc__ to be redeclared by user
@@ -594,6 +600,13 @@ class Scope(object):
                         elif type.same_ptr_args_without_cv_with(alt_type):
                             error(pos, "Cypclass method const-overloads another method: not supported yet")
 
+                        # Disallow qualifier overloads
+                        elif type.same_args_without_qualifiers_with(alt_type):
+                            error(pos, "Cannot overload on cypclass qualifiers")
+                            if alt_entry.pos is not None:
+                                error(alt_entry.pos, "Conflicting method is defined here")
+                            break
+
                         # if an overloaded alternative has narrower argument types than another, then the method
                         # actually called will depend on the static type of the arguments
                         # we actually also disallow methods where each argument is either narrower or larger
@@ -601,6 +614,7 @@ class Scope(object):
                             error(pos, "Cypclass overloaded method with narrower or larger arguments")
                             if alt_entry.pos is not None:
                                 error(alt_entry.pos, "Conflicting method is defined here")
+                            break
 
                 # normal cpp case
                 else: