// filename:c2011-7-16-1-4-ex.c
// original examples and/or notes:
// 		(c) ISO/IEC JTC1 SC22 WG14 N1570, April 12, 2011
// 			C2011 7.16.1.4 The va_start macro
// compile and output mechanism:
// 		(c) Ogawa Kiyoshi, kaizen@gifu-u.ac.jp, December.29, 2013
// compile errors and/or wornings:
// 		(c) Apple LLVM version 4.2 (clang-425.0.27) (based on LLVM 3.2svn)
// 			Target: x86_64-apple-darwin11.4.2 //Thread model: posix
// 		(c) LLVM 2003-2009 University of Illinois at Urbana-Champaign.
#include <stdio.h>
		
// Example 1
#include <stdarg.h>
#define MAXARGS 31

void f2(int n, char ** array){
	printf("f2 %d, %s ", n,array[n]);
}

void f4(int n, char ** array){
	printf("f4 %d, %s ", n,array[n]);
}	

void f1(int n_ptrs, ...)
{
va_list ap;
char *array[MAXARGS];
int ptr_no = 0;
if (n_ptrs > MAXARGS)
n_ptrs = MAXARGS;
va_start(ap, n_ptrs);
while (ptr_no < n_ptrs)
array[ptr_no++] = va_arg(ap, char *);
va_end(ap);
f2(n_ptrs, array);
}

// Example 2
//#include <stdarg.h>
//#define MAXARGS 31
void f3(int n_ptrs, int f4_after, ...)
{
va_list ap, ap_save;
char *array[MAXARGS];
int ptr_no = 0;
if (n_ptrs > MAXARGS)
n_ptrs = MAXARGS;
va_start(ap, f4_after);
while (ptr_no < n_ptrs) {
array[ptr_no++] = va_arg(ap, char *);
if (ptr_no == f4_after)
va_copy(ap_save, ap);
}
va_end(ap);
f2(n_ptrs, array);
// Now process the saved copy.
n_ptrs -= f4_after;
ptr_no = 0;
while (ptr_no < n_ptrs)
array[ptr_no++] = va_arg(ap_save, char *);
va_end(ap_save);
f4(n_ptrs, array);
}

int main(void)
{
	char * msg[] = {"C2011","ISO/IEC9899","N1570","April12,2011","7.8.1", "Macros","for","format","specifiers"};
			int i=4, j=2;
	f1(j,msg);f3(j,i,msg);
return printf("7.16.1.4 The va_start macro\n");
}
// output1(LLVM3.2) may be 
//f2 2, (null) f2 2, ?f?f? f4 -2, UH??I??H??H)?H9?r5H??Pw4????t?H???H????u???t?H?ƈH????u?L??]?? 7.16.1.4 The va_start macro
// output2(GCC4.9)
// f2 2, (null) f2 2, h?? f4 -2, ?
// ^? 7.16.1.4 The va_start macro