1 /* Copyright (C) 2000 Free Software Foundation.
2
3 If the argument to va_end() has side effects, test whether side
4 effects from that argument are honored.
5
6 Written by Kaveh R. Ghazi, 10/31/2000. */
7
8 #include <stdarg.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11
12 #ifndef __GNUC__
13 #define __attribute__(x)
14 #endif
15
16 static void __attribute__ ((__format__ (__printf__, 1, 2)))
doit(const char * s,...)17 doit (const char *s, ...)
18 {
19 va_list *ap_array[3], **ap_ptr = ap_array;
20
21 ap_array[0] = malloc (sizeof(va_list));
22 ap_array[1] = NULL;
23 ap_array[2] = malloc (sizeof(va_list));
24
25 va_start (*ap_array[0], s);
26 vprintf (s, **ap_ptr);
27 /* Increment the va_list pointer once. */
28 va_end (**ap_ptr++);
29
30 /* Increment the va_list pointer a second time. */
31 ap_ptr++;
32
33 va_start (*ap_array[2], s);
34 /* If we failed to increment ap_ptr twice, then the parameter passed
35 in here will dereference NULL and should cause a crash. */
36 vprintf (s, **ap_ptr);
37 va_end (**ap_ptr);
38
39 /* Just in case, If *ap_ptr is NULL abort anyway. */
40 if (*ap_ptr == 0)
41 abort();
42 }
43
main()44 int main()
45 {
46 doit ("%s", "hello world\n");
47 exit (0);
48 }
49