Re: [CPP patch]: -M default name

["Zack Weinberg" <zackw at Stanford dot EDU>]

On Thu, Feb 08, 2001 at 08:19:08PM +0000, Neil Booth wrote:
> Zack Weinberg wrote:-
> 
> > I'm not sure how it does work now, but here's how I think it should
> > work: if -M[M] and not -MT, turn -o into -MQ.  i.e.
> > 
> > (cpp|gcc) -M foo.c -o foo.o
> > 
> > means
> > 
> > gcc -E -M foo.c -MQ foo.o
> 
> Right, that's what I'm aiming for; gcc will do this after the patch
> but cpp won't.  I'll come back to cpp.

Okay.

> > > Note the specs change - the specs currently instruct the driver to
> > > delete the output file in case of an error, which is just as bad as
> > > truncating it, so I'm removing that.
> > 
> > Um.  No.  If you don't delete the output file, then when you restart
> > make, it will think the output file is up to date when it isn't.
> 
> I don't understand - by output file I meant the ".o" file, which
> shouldn't even be touched by the command line above (i.e. command
> lines with -M or -MM).  If it was out of date before, it will still be
> out of date, no?

I misunderstood; I thought this affected the case where we are
generating an object file.

zw