Date: Wed, 21 May 1997 20:14:47 +0100 From: Brian Somers <brian@awfulhak.org> To: Michael Smith <msmith@atrad.adelaide.edu.au> Cc: jgrosch@superior.mooseriver.com, hackers@FreeBSD.ORG Subject: Re: Porting question Message-ID: <199705211914.UAA18664@awfulhak.demon.co.uk> In-Reply-To: Your message of "Wed, 21 May 1997 15:33:07 %2B0930." <199705210603.PAA09769@genesis.atrad.adelaide.edu.au>
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> Josef Grosch stands accused of saying:
> > I know this issue has been beat to death several times before BUT.....
> >
> > I am porting a piece of code to FreeBSD and gcc bitches about this;
> >
> > extern char* sys_errlist[];
> >
> > Now the fast way to handle this is;
> >
> > #ifndef __FreeBSD__
> > extern char* sys_errlist[];
> > #endif
> >
> > But this is very non-portable. Any suggestions as the correct way to
> > handle this would be helpful.
>
> Traditional is
>
> #ifndef HAVE_SYS_ERRLIST
> extern char* sys_errlist[];
> #endif
>
> or, if you can guarantee that <sys/param.h> has been included, you can
> test the BSD macro.
Hmm, of course you mean extern const char * const sys_errlist[]. If
this prototype is used, it doesn't matter if you've included stdio.
If it conflicts with anything, that something is broken - a poor
reason for breaking your own code IMO.
Maybe gcc should allow the "strengthening" of a prototype - so
saying
extern char *sys_errlist[];
extern const char *sys_errlist[];
extern const char * const sys_errlist[];
is ok (probably warned about under -pedantic or with its own -W),
but
extern const char *sys_errlist[];
extern char *sys_errlist[];
is an error. That way, people can successfully "overload"
include files with others that say "#include "/usr/include/..."
(there's a #include_next or something somewhere in gcc too isn't
there) and then "fix" things like this (rather than having to
#define them away before #including the file).
Look at it like defaulting arguments in C++ - you can get stricter
everytime you prototype a function.
> > Josef Grosch | Another day closer to a | FreeBSD 2.2.1
>
> --
> ]] Mike Smith, Software Engineer msmith@gsoft.com.au [[
> ]] Genesis Software genesis@gsoft.com.au [[
> ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[
> ]] realtime instrument control. (ph) +61-8-8267-3493 [[
> ]] Unix hardware collector. "Where are your PEZ?" The Tick [[
--
Brian <brian@awfulhak.org>, <brian@freebsd.org>
<http://www.awfulhak.org>;
Don't _EVER_ lose your sense of humour....
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