Path: utzoo!mnetor!uunet!husc6!necntc!ima!haddock!karl
From: karl@haddock.ISC.COM (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Volatile is Necessary
Message-ID: <3353@haddock.ISC.COM>
Date: 6 Apr 88 21:58:28 GMT
References: <7569@brl-smoke.ARPA> <-63852956@sneaky>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Boston
Lines: 12

In article <-63852956@sneaky> gordon@sneaky.UUCP writes:
># define setjmp(env) (_builtin_setjmp(env) + 0)
>where the +0 ensures that &setjmp draws an error message

It doesn't work that way.  "&setjmp" (more generally, any use of a function-
-like macro without a left parenthesis) will not be recognized as a macro and
hence no substitution will take place.  (This feature allows you to take the
address of putchar, for example, even if it's implemented as a macro.)  So you
might as well use "#define setjmp(env) __builtin_setjmp(env)" and let the
linker complain about the unresolved symbol "setjmp".

Karl W. Z. Heuer (ima!haddock!karl or karl@haddock.isc.com), The Walking Lint