libgo/runtime/go-type-interface.c

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