__STDC__ and non-strictly conforming ANSI C compilers
Henry Spencer
henry at utzoo.uucp
Fri Dec 16 04:38:22 AEST 1988
In article <9167 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>) writes:
>Please don't define __STDC__ at all for non standard-
>conforming implementations...
>I assume full ANSI C conformance when [#if __STDC__] succeeds.
>I don't think I should have to write
> #if __STDC__ == 1
>which would force me to perform massive edits when the next
>C standard bumps the value of __STDC__ to 2.
Uh, Doug, why would you have to write the "== 1"? "#if __STDC__" will
fail if __STDC__ is defined as zero. "#ifdef __STDC__" is a different
story, mind you, but as I have pointed out in another posting, the
difference between the two could be useful.
The October draft says "__STDC__ The decimal constant 1, intended to
indicate a conforming implementation.". It does not seem to me that
defining __STDC__ as 0 for an ANSI-like but non-conforming implementation
is *clearly* a violation of this. Furthermore, it would appear to me
that only "#if __STDC__" is guaranteed to tell you whether it's a
conforming implementation, and "#ifdef __STDC__" should not be relied on,
given the existing wording.
--
"God willing, we will return." | Henry Spencer at U of Toronto Zoology
-Eugene Cernan, the Moon, 1972 | uunet!attcan!utzoo!henry henry at zoo.toronto.edu
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