blob: 83217ab95b3a649570e64f695ffcdb64cd8ad6d9 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
|
/* go-can-convert-interface.c -- can we convert to an interface?
Copyright 2009 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file. */
#include "go-assert.h"
#include "go-type.h"
#include "interface.h"
/* Return whether we can convert from the type in FROM_DESCRIPTOR to
the interface in TO_DESCRIPTOR. This is used for type
switches. */
_Bool
__go_can_convert_to_interface (
const struct __go_type_descriptor *to_descriptor,
const struct __go_type_descriptor *from_descriptor)
{
const struct __go_interface_type *to_interface;
int to_method_count;
const struct __go_interface_method *to_method;
const struct __go_uncommon_type *from_uncommon;
int from_method_count;
const struct __go_method *from_method;
int i;
/* In a type switch FROM_DESCRIPTOR can be NULL. */
if (from_descriptor == NULL)
return 0;
__go_assert (to_descriptor->__code == GO_INTERFACE);
to_interface = (const struct __go_interface_type *) to_descriptor;
to_method_count = to_interface->__methods.__count;
to_method = ((const struct __go_interface_method *)
to_interface->__methods.__values);
from_uncommon = from_descriptor->__uncommon;
if (from_uncommon == NULL)
{
from_method_count = 0;
from_method = NULL;
}
else
{
from_method_count = from_uncommon->__methods.__count;
from_method = ((const struct __go_method *)
from_uncommon->__methods.__values);
}
for (i = 0; i < to_method_count; ++i)
{
while (from_method_count > 0
&& (!__go_ptr_strings_equal (from_method->__name,
to_method->__name)
|| !__go_ptr_strings_equal (from_method->__pkg_path,
to_method->__pkg_path)))
{
++from_method;
--from_method_count;
}
if (from_method_count == 0)
return 0;
if (!__go_type_descriptors_equal (from_method->__mtype,
to_method->__type))
return 0;
++to_method;
++from_method;
--from_method_count;
}
return 1;
}
|
