/* 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 #include #include #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); }