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
77
78
79
80
81
82
83
84
|
#include <string.h>
#include "config.h"
/**
* cast - routines for safer casting.
*
* Often you want to cast in a limited way, such as removing a const or
* switching between integer types. However, normal casts will work on
* almost any type, making them dangerous when the code changes.
*
* These C++-inspired macros serve two purposes: they make it clear the
* exact reason for the cast, and they also (with some compilers) cause
* errors when misused.
*
* Based on Jan Engelhardt's libHX macros: http://libhx.sourceforge.net/
*
* Author: Jan Engelhardt
* Maintainer: Rusty Russell <rusty@rustcorp.com.au>
* License: LGPL (v2.1 or any later version)
*
* Example:
* // Given "test" contains "3 t's in 'test string'
* #include <ccan/cast/cast.h>
* #include <stdint.h>
* #include <stdio.h>
*
* // Find char @orig in @str, if @repl, replace them. Return number.
* static size_t find_chars(char *str, char orig, char repl)
* {
* size_t i, count = 0;
* for (i = 0; str[i]; i++) {
* if (str[i] == orig) {
* count++;
* if (repl)
* str[i] = repl;
* }
* }
* return count;
* }
*
* // Terrible hash function.
* static uint64_t hash_string(const unsigned char *str)
* {
* size_t i;
* uint64_t hash = 0;
* for (i = 0; str[i]; i++)
* hash += str[i];
* return hash;
* }
*
* int main(int argc, char *argv[])
* {
* uint64_t hash;
*
* // find_chars wants a non-const string, but doesn't
* // need it if repl == 0.
* printf("%zu %c's in 'test string'\n",
* find_chars(cast_const(char *, "test string"),
* argv[1][0], 0),
* argv[1][0]);
*
* // hash_string wants an unsigned char.
* hash = hash_string(cast_signed(unsigned char *, argv[1]));
*
* // Need a long long to hand to printf.
* printf("Hash of '%s' = %llu\n", argv[1],
* cast_static(unsigned long long, hash));
* return 0;
* }
*
*/
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;
}
return 1;
}
|
