libgo/runtime/go-interface-val-compare.c

   1 /* go-interface-val-compare.c -- compare an interface to a value.
   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 "go-type.h"
   8 #include "interface.h"
   9
  10 /* Compare two interface values.  Return 0 for equal, not zero for not
  11    equal (return value is like strcmp).  */
  12
  13 int
  14 __go_interface_value_compare (
  15     struct __go_interface left,
  16     const struct __go_type_descriptor *right_descriptor,
  17     const void *val)
  18 {
  19   const struct __go_type_descriptor *left_descriptor;
  20
  21   if (left.__methods == NULL)
  22     return 1;
  23   left_descriptor = left.__methods[0];
  24   if (!__go_type_descriptors_equal (left_descriptor, right_descriptor))
  25     return 1;
  26   if (__go_is_pointer_type (left_descriptor))
  27     return left.__object == val ? 0 : 1;
  28   if (!left_descriptor->__equalfn (left.__object, val,
  29                                    left_descriptor->__size))
  30     return 1;
  31   return 0;
  32 }