Enforce stricter cypclass overloading rules

Cython/Compiler/PyrexTypes.py

@@ -3094,8 +3094,8 @@ class CFuncType(CType):
         return rhs_type.same_c_signature_as_resolved_type(self, exact_semantics=False) \
             and not (self.nogil and not rhs_type.nogil)
 
-    def declaration_code(self, entity_code,
-                         for_display = 0, dll_linkage = None, pyrex = 0,
+    def declarator_code(self, entity_code,
+                         for_display = 0, pyrex = 0,
                          with_calling_convention = 1):
         arg_decl_list = []
         for arg in self.args[:len(self.args)-self.optional_arg_count]:
@@ -3132,9 +3132,13 @@ class CFuncType(CType):
                 cc = ""
         if self.is_const_method:
             trailer += " const"
-        return self.return_type.declaration_code(
-            "%s%s(%s)%s" % (cc, entity_code, arg_decl_code, trailer),
-            for_display, dll_linkage, pyrex)
+        return "%s%s(%s)%s" % (cc, entity_code, arg_decl_code, trailer)
+
+    def declaration_code(self, entity_code,
+                         for_display = 0, dll_linkage = None, pyrex = 0,
+                         with_calling_convention = 1):
+        declarator_code = self.declarator_code(entity_code, for_display, pyrex, with_calling_convention)
+        return self.return_type.declaration_code(declarator_code, for_display, dll_linkage, pyrex)
 
     def function_header_code(self, func_name, arg_code):
         if self.is_const_method:

Cython/Compiler/Symtab.py

@@ -554,28 +554,20 @@ class Scope(object):
                                 cpp_override_allowed = True
                                 continue
 
+                            # in a cypclass, if the arguments are compatible
+                            # then the whole signature must be identical (return type excluded)
+                            old_declarator = alt_entry.type.declarator_code(name, for_display = 1).strip()
+                            new_declarator = type.declarator_code(name, for_display = 1).strip()
+                            if not new_declarator == old_declarator:
+                                comparison_message = " ---> %s\nvs -> %s" % (new_declarator, old_declarator)
+                                error(pos, "Cypclass method with compatible arguments but incompatible signature:\n%s"
+                                           % comparison_message)
+                                if alt_entry.pos is not None:
+                                        error(alt_entry.pos, "Conflicting method is defined here")
+
                         # Any inherited method is visible
                         # until overloaded by a method with the same signature
                         if alt_entry.is_inherited:
-
-                            # in a cypclass, if the arguments are compatible
-                            # then the whole signature must also be compatible
-                            if self.is_cyp_class_scope:
-                                if not type.compatible_signature_with(alt_entry.type, skip_args=1):
-                                    error(pos, "Cypclass overriding method with incompatible return type")
-                                    if alt_entry.pos is not None:
-                                        error(alt_entry.pos, "Overriden method is defined here")
-
-                                # 'CFuncType.compatible_signature_with' doesn't compare constness, so we're doing it here.
-                                # TODO: Maybe it should.
-                                elif (type.is_const_method and not alt_entry.type.is_const_method
-                                      or not type.is_const_method and alt_entry.type.is_const_method):
-                                    print(type.is_const_method)
-                                    print(alt_entry.type.is_const_method)
-                                    error(pos, "Cypclass overriding method with conflicting constness")
-                                    if alt_entry.pos is not None:
-                                        error(alt_entry.pos, "Overriden method is defined here")
-
                             previous_alternative_indices.append(index)
                             cpp_override_allowed = True
                             continue