Viewing file: va-arg-21.c (1.09 KB) -rw-r--r-- Select action/file-type: (+) | (+) | (+) | Code (+) | Session (+) | (+) | SDB (+) | (+) | (+) | (+) | (+) | (+) |
/* Copyright (C) 2000 Free Software Foundation.
If the argument to va_end() has side effects, test whether side effects from that argument are honored.
Written by Kaveh R. Ghazi, 10/31/2000. */
#include <stdarg.h> #include <stdio.h> #include <stdlib.h>
#ifndef __GNUC__ #define __attribute__(x) #endif
static void __attribute__ ((__format__ (__printf__, 1, 2))) doit (const char *s, ...) { va_list *ap_array[3], **ap_ptr = ap_array;
ap_array[0] = malloc (sizeof(va_list)); ap_array[1] = NULL; ap_array[2] = malloc (sizeof(va_list)); va_start (*ap_array[0], s); vprintf (s, **ap_ptr); /* Increment the va_list pointer once. */ va_end (**ap_ptr++);
/* Increment the va_list pointer a second time. */ ap_ptr++; va_start (*ap_array[2], s); /* If we failed to increment ap_ptr twice, then the parameter passed in here will dereference NULL and should cause a crash. */ vprintf (s, **ap_ptr); va_end (**ap_ptr);
/* Just in case, If *ap_ptr is NULL abort anyway. */ if (*ap_ptr == 0) abort(); }
int main() { doit ("%s", "hello world\n"); exit (0); }
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