preprocessor #include

[vippstar]

Is this a valid implementation of stdio.h?

-- stdio.h --
#ifndef __STDIO_H
#define __STDIO_H
/* all the necessary declarations etc */

void __dummy(void);
void __dummy(void) { return;
#include "closebracket.h"
#endif /* __STDIO_H */
-- stdio.h --

-- closebracket.h --
}
-- closebracket.h --

And if this is valid, how many files can stdio.h include and remain to
be valid?
5.2.4.1 mentions a requirement of at least 15 nesting levels of
#included files.
Is it the sum of both the implementations inclusions and the
programmers inclusions? And if so, does that mean the programmer
cannot portably have more than 1 nesting level, since the
implementation is free to use 62 nesting levels?

Thanks for all the replies.

 

[vippstar]

And if this is valid, how many files can stdio.h include and remain to
be valid?
5.2.4.1 mentions a requirement of at least 15 nesting levels of
#included files.
Is it the sum of both the implementations inclusions and the
programmers inclusions? And if so, does that mean the programmer
cannot portably have more than 1 nesting level, since the
implementation is free to use 62 nesting levels?

Whoops, 14 nesting levels.

 

[Thad Smith]

Whoops, 14 nesting levels.

Since the user doesn't have control over the nesting levels of system
headers, I interpret the constraint to mean that the user can nest 14
#include files, then #include any system header.

As the implementor, you can nest the system headers as deeply as you like,
as long as you can accommodate the limit, with system header counting as
one level.