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

   1 /* go-eface-val-compare.c -- compare an empty interface with a value.
   2
   3    Copyright 2010 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 an empty interface with a value.  Return 0 for equal, not
  12    zero for not equal (return value is like strcmp).  */
  13
  14 intgo
  15 __go_empty_interface_value_compare (
  16     struct __go_empty_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   left_descriptor = left.__type_descriptor;
  23   if (((uintptr_t) left_descriptor & reflectFlags) != 0)
  24     runtime_panicstring ("invalid interface value");
  25   if (left_descriptor == NULL)
  26     return 1;
  27   if (!__go_type_descriptors_equal (left_descriptor, right_descriptor))
  28     return 1;
  29   if (__go_is_pointer_type (left_descriptor))
  30     return left.__object == val ? 0 : 1;
  31   if (!left_descriptor->__equalfn (left.__object, val,
  32                                    left_descriptor->__size))
  33     return 1;
  34   return 0;
  35 }