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 "runtime.h"
   8 #include "go-type.h"
   9 #include "interface.h"
  10
  11 /* Compare two interface values.  Return 0 for equal, not zero for not
  12    equal (return value is like strcmp).  */
  13
  14 intgo
  15 __go_interface_value_compare (
  16     struct __go_interface left,
  17     const struct __go_type_descriptor *right_descriptor,
  18     const void *val)
  19 {
  20   const struct __go_type_descriptor *left_descriptor;
  21
  22   if (left.__methods == NULL)
  23     return 1;
  24   left_descriptor = left.__methods[0];
  25   if (!__go_type_descriptors_equal (left_descriptor, right_descriptor))
  26     return 1;
  27   if (__go_is_pointer_type (left_descriptor))
  28     return left.__object == val ? 0 : 1;
  29   if (!left_descriptor->__equalfn (left.__object, val,
  30                                    left_descriptor->__size))
  31     return 1;
  32   return 0;
  33 }