libgo/runtime/go-interface-compare.c

   1 /* go-interface-compare.c -- compare two interface values.
   2
   3    Copyright 2009 The Go Authors. All rights reserved.
   4    Use of this source code is governed by a BSD-style
   5    license that can be found in the LICENSE file.  */
   6
   7 #include "interface.h"
   8
   9 /* Compare two interface values.  Return 0 for equal, not zero for not
  10    equal (return value is like strcmp).  */
  11
  12 int
  13 __go_interface_compare (struct __go_interface left,
  14                         struct __go_interface right)
  15 {
  16   const struct __go_type_descriptor *left_descriptor;
  17
  18   if (left.__methods == NULL && right.__methods == NULL)
  19     return 0;
  20   if (left.__methods == NULL || right.__methods == NULL)
  21     return 1;
  22   left_descriptor = left.__methods[0];
  23   if (!__go_type_descriptors_equal (left_descriptor, right.__methods[0]))
  24     return 1;
  25   if (__go_is_pointer_type (left_descriptor))
  26     return left.__object == right.__object ? 0 : 1;
  27   if (!left_descriptor->__equalfn (left.__object, right.__object,
  28                                    left_descriptor->__size))
  29     return 1;
  30   return 0;
  31 }