NetNews Offline 2/NetNews Offline Volume 2.iso/news/comp/lang/c-part2/14135

Text File | 1996-08-05 | 1.6 KB | 53 lines

Path: mail2news.demon.co.uk!setch.demon.co.uk
From: Mark Setchell <[e-mail]>
Newsgroups: comp.lang.c
Subject: #including everything
Date: Fri, 12 Apr 96 08:24:41 GMT
Organization: DeltaPlusLtd
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Does anyone have an opinion about how sensible it is to #include all
standard system header files in C programs? I work on a project with
approximately 2000 files and 500,000 lines of code and every file
has a long piece at the start like this:

#include <stdio.h>
#include <errno.h>
#if !defined(SGI) && !defined(HPUX)
#include <x.h>
#else
#if !defined(IBM_R2) && !defined(CRAY)
#include <y.h>
#endif
#endif

This is obviously a maintenance nightmare, porting is no fun either. I
am thinking of making a single include file with all system headers in
it (i.e. ones in <> as opposed to those in "").

I suspect the disadvantages are:
1) If it changes, all files have to be rebuilt - but that's ok it won't
   change often
2) It may bloat the size of the binaries by including unused variables,
   but that's not really a problem on Virtual Memory machines, and the
   increase in size isn't much anyway.
3) ???

Weighed against this, the advantages are:
1) porting and maintenance become easier with only one file to maintain
2) all system calls/functions are guaranteed to be prototyped
3) ???

Also, which system files should I #include?

TIA
--
Mark Setchell ([e-mail])
17 Hurst Place, Gillingham, Kent, England ME8 9AS
Tel: [phone]
Fax: [phone]