How to force cpp to abort?

[Michael P. Gerlek]

In article <17377 at haddock.ima.isc.com>,
      karl at haddock.ima.isc.com (Karl Heuer) writes:
> In article <MIKEG.90Aug11180036 at c3.c3.lanl.gov> I (Michael P. Gerlek) wrote:
> > [If none of the preprocessor conditions hold, I want to abort.  How?]
>
>  Use `#error put_some_text_here'.  This is the ANSI C solution.
>
>  I presume you also want this to work on pre-ANSI compilers (since you used
>  `#else\n#if' instead of the cleaner `#elif' construct).

Yup, bingo.

>  If you add a leading
>  space, i.e. ` #error', it should be invisible to pre-ANSI compilers that would
>  complain about unknown cpp-control lines.  (ANSI allows horizontal whitespace
>  before `#' as well as after.)  Then an attempt to compile in a pre-ANSI
>  environment where none of the conditionals holds should get an `illegal
>  character' warning when the `#' is encountered in the next compiler pass.
>
>   If you insist on aborting during the preprocessor pass, you could use
>  `#include "/-/put_some_text_here/-/", which is what I used to use before
>  `#error' was invented.

Most of the email responses I got said the same thing, and it's
almost what I want (I missed the #error directive when I looked thru
K&R) --  But it's still ANSI-only...


So, academic question: from what I understand, #error isn't guaranteed
to stop compilation.  Can someone tell me why there isn't something
like an "#abort error-message-here" directive that *would* terminate?
Seems like this'd be really useful...


[  M.P.Gerlek (mikeg at lanl.gov)                 -
[  Los Alamos Nat'l Lab / Merrimack College    -
[  Disclaimer: Yes, Mom, I'll play nice.       -
[  "My other machine *used* to be an XMP."     -