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From: utoddl@uncecs.edu (Todd M. Lewis)
Newsgroups: comp.lang.c
Subject: Re: A solution to the multiple inclusion problem
Summary: could this be a compiler switch
Keywords: #include c c++
Message-ID: <1989Oct25.121308.1925@uncecs.edu>
Date: 25 Oct 89 12:13:08 GMT
References: <14240@well.UUCP> <15316@bloom-beacon.MIT.EDU> <1989Oct24.153611.12168@lotus.com>
Distribution: comp
Organization: UNC Educational Computing Service
Lines: 25

In article <1989Oct24.153611.12168@lotus.com>, mgordon@lotus.com (PCSD Mac) writes:
> 
> How about a new preprocessor directive that means "include this file only 
> if it hasn't already been included", say "#require"?  The "preprocessor"
> would simply keep a table of files that have already been included and use 
> it to avoid including the same #required file more than once.  There will 
> always be files you really do want to #include multiple times, so you can't
> change the meaning of #include.

Could this not be done with a compiler switch?  You could switch it
off if you really did have to include a file multiple times, but
this doesn't happen too often in Real Life (not mine anyway).

Actually, the compiler I use lets me dump its symbol table to a 
file.  Later, I compile with a switch which says "use this here file
to preload your symbol table", and I don't have to process all
those include files every time.  Works like a charm.  If I then
#include a file that is one of the pre-cooked ones in dump file, the
compiler doesn't include it again.  This cuts compile times way down.
_____        
  |      Todd M. Lewis            Disclaimer: If you want my employer's
  ||\/|  utoddl@ecsvax.uncecs.edu             ideas, you'll have to
  ||  || utoddl@ecsvax.bitnet                 _buy_ them. 
   |  ||     
       |___   ("Prgrms wtht cmmnts r lk sntncs wtht vwls." --TML)