blob: 8135d1ee8ee4a90cbb94189f6f0f2fafc2dd9bcf (
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
|
#include "config.h"
#include <stdio.h>
#include <string.h>
/**
* ptrint - Encoding integers in pointer values
*
* Library (standard or ccan) functions which take user supplied
* callbacks usually have the callback supplied with a void * context
* pointer. For simple cases, it's sometimes sufficient to pass a
* simple integer cast into a void *, rather than having to allocate a
* context structure. This module provides some helper macros to do
* this relatively safely and portably.
*
* The key characteristics of these functions are:
* ptr2int(int2ptr(val)) == val
* and
* !int2ptr(val) == !val
* (i.e. the transformation preserves truth value).
*
* Example:
* #include <ccan/ptrint/ptrint.h>
*
* static void callback(void *opaque)
* {
* int val = ptr2int(opaque);
* printf("Value is %d\n", val);
* }
*
* void (*cb)(void *opaque) = callback;
*
* int main(int argc, char *argv[])
* {
* int val = 17;
*
* (*cb)(int2ptr(val));
* exit(0);
* }
*
* License: CC0 (Public domain)
* Author: David Gibson <david@gibson.dropbear.id.au>
*/
int main(int argc, char *argv[])
{
/* Expect exactly one argument */
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0) {
printf("ccan/build_assert\n");
return 0;
}
if (strcmp(argv[1], "testdepends") == 0) {
printf("ccan/array_size\n");
return 0;
}
return 1;
}
|
