libgo/runtime/go-type-eface.c

   1 /* go-type-eface.c -- hash and equality empty interface functions.
   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 "interface.h"
   8 #include "go-panic.h"
   9 #include "go-type.h"
  10
  11 /* A hash function for an empty interface.  */
  12
  13 size_t
  14 __go_type_hash_empty_interface (const void *vval,
  15                                 size_t key_size __attribute__ ((unused)))
  16 {
  17   const struct __go_empty_interface *val;
  18   const struct __go_type_descriptor *descriptor;
  19   size_t size;
  20
  21   val = (const struct __go_empty_interface *) vval;
  22   descriptor = val->__type_descriptor;
  23   if (descriptor == NULL)
  24     return 0;
  25   size = descriptor->__size;
  26   if (__go_is_pointer_type (descriptor))
  27     return descriptor->__hashfn (&val->__object, size);
  28   else
  29     return descriptor->__hashfn (val->__object, size);
  30 }
  31
  32 /* An equality function for an empty interface.  */
  33
  34 _Bool
  35 __go_type_equal_empty_interface (const void *vv1, const void *vv2,
  36                                  size_t key_size __attribute__ ((unused)))
  37 {
  38   const struct __go_empty_interface *v1;
  39   const struct __go_empty_interface *v2;
  40   const struct __go_type_descriptor* v1_descriptor;
  41   const struct __go_type_descriptor* v2_descriptor;
  42
  43   v1 = (const struct __go_empty_interface *) vv1;
  44   v2 = (const struct __go_empty_interface *) vv2;
  45   v1_descriptor = v1->__type_descriptor;
  46   v2_descriptor = v2->__type_descriptor;
  47   if (((uintptr_t) v1_descriptor & reflectFlags) != 0
  48       || ((uintptr_t) v2_descriptor & reflectFlags) != 0)
  49     __go_panic_msg ("invalid interface value");
  50   if (v1_descriptor == NULL || v2_descriptor == NULL)
  51     return v1_descriptor == v2_descriptor;
  52   if (!__go_type_descriptors_equal (v1_descriptor, v2_descriptor))
  53     return 0;
  54   if (__go_is_pointer_type (v1_descriptor))
  55     return v1->__object == v2->__object;
  56   else
  57     return v1_descriptor->__equalfn (v1->__object, v2->__object,
  58                                      v1_descriptor->__size);
  59 }