// filename:c2011-6-8-3-ex.c
// original examples and/or notes:
// 		(c) ISO/IEC JTC1 SC22 WG14 N1570, April 12, 2011
// http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf
// 			C2011 6.8.3 Expression and null statements
// compile and output mechanism:
// 		(c) Ogawa Kiyoshi, kaizen@gifu-u.ac.jp, December.xx, 2013
// compile errors and/or wornings:
// 1	(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.
// 2    gcc-4.9 (GCC) 4.9.0 20131229 (experimental)
//      Copyright (C) 2013 Free Software Foundation, Inc.
#include <stdio.h>
// Example 1
int p(int);
/* ... */
int p(int i){ return printf("i=%d ",i),i;}

int main(void)
{
(void)p(0);
	
// Example 2
char *s;
/* ... */printf("s=%s ",s);
while (*s++ != '\0')
printf("s=%d ",(int)*s);

// Example 3
int loop1, loop2, want_out;
printf("loop1=%d ",loop1);printf("loop2=%d ",loop2);printf("want_out=%d ",want_out);
while (loop1) {
/* ... */ printf("loop1=%d ",loop1);
while (loop2) {
/* ... */ printf("loop2=%d ",loop2);
if (want_out)
printf("want_out=%d ",want_out);goto end_loop1;
/* ... */
}
/* ... */
end_loop1: ;
}
return printf("\n 6.8.3 Expression and null statements %d %d\n",p(1),*s);	
}
// 1. LLVM3.2 output may be
//i=0 s= loop1=0 loop2=0 want_out=0 i=1 
// 6.8.3 Expression and null statements 1 0
// 2. GCC4.9 output
// Segmentation fault: 11