Re: problems with c89 and c++ on z/OS

[Paul Eggert]

> From: "James Tison" <address@hidden>
> Date: Tue, 2 Jul 2002 17:25:57 -0400
> 
> If someone can quote me chapter and verse from the Standard
> on the required behavior, I'll be happy to file a bug report against it.

Page 163 section 6.10.2 line 1 of the C99 standard says:

        Constraints

        A #include directive shall identify a header or source file that can
        be processed by the implementation.

The standard requires that every constraint violation must be
diagnosed, so a diagnostic is required from the C compiler if a
program attempts to include a nonexistent header or source file.

There is no requirement that c99 (or c89 or cc) must return a nonzero
error status in this case.  However, longstanding tradition is that
nonexistent include files are serious errors, warranting a nonzero
exit status.

Many programs rely on the traditional behavior in order to configure
themselves properly.  No program that I know of relies on the other
behavior (where missing include files are not considered to be
errors).  So it's not useful for a compiler to depart from the
longstanding tradition here.