Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!munnari!otc!metro!basser!usage!elecvax!spinifex!malcolmp
From: malcolmp@spinifex.eecs.unsw.oz (Malcolm Purvis)
Newsgroups: comp.lang.c++
Subject: Re: Multiple inclusion of virtual tables...
Message-ID: <340@spinifex.eecs.unsw.oz>
Date: 23 Mar 89 01:08:12 GMT
References: <GRUNWALD.89Mar17220936@flute.cs.uiuc.edu>
Organization: Kenso Kindi (UNSW)
Lines: 33

From article <GRUNWALD.89Mar17220936@flute.cs.uiuc.edu>, by grunwald@flute.cs.uiuc.edu:
>
>I'd thought about +e<name> -- the problem being that
>	(a) this requires changing the entire makefile
>	(b) requires a very strict naming convention for files.
>
>E.g., If I have class ``SimulationMultiplexor'' (I do),
>then I need to have a file with the same name. That's not so bad,
>except on SysV (which, thank god, I'm not using).
>
>Using #pragma means you need to change one line in the Makefile
>(the one defining C++FLAGS) and lets you use whatever file
>naming convention you want.

[My apologies if this topic has discussed in depth before.]

	Couldn't you change the compiler to do the equivalent of +e<name>
automatically so you wouldn't have these problems?  You could put in rules
that say if when compiling a file it finds a constructor/destructor for a
class, then the vtbl for that class is defined in this file, otherwise it is
declared external.  This results in the vtbl being declared in one place
just as with +e<name>, but you could then name your files however you like,
and also you wouldn't have to change the Makefile.

	Of course the contructor/destructor rule is probably insufficient by
itself, especially if the class has all inline member functions (inline
virtual functions? How strange), but you should get the idea.

	Malcolm Purvis (malcolmp@{spectrum,spinifex}.eecs.unsw.oz)
		University of NSW, Sydney, Australia.

Honours: The students treat you like geniuses, the staff like postgrads, and
the administration like children........