Re: make: Check_Cwd_av handle -C or remove?

[Alan Barrett <apb%cequrux.com@localhost>]

On Fri, 18 Jan 2013, Simon Gerraty wrote:
> I added the Check_Cwd_av logic at least 10 years ago, to avoid 
> the need to fix lots of makefiles which didn't work with 
> MAKEOBJDIRPREFIX.

If I understad correctly, that was a workaround for buggy 
Makefiles that assumed that they could do

        sometarget:
                ${MAKE} othertarget

when they should really have done

        sometarget:
                (cd ${.CURDIR} && ${MAKE} othertarget)

> I suspect the need for it has passed.  Building with separate 
> obj trees (via MAKEOBJDIRPREFIX etc), seems almost universal 
> now.  Perhaps it is time to retire this check or perhaps disable 
> it by default?

I think that removing it would be fine.  I don't think that it 
was ever a good idea.  In other words, I think that people who 
write incorrect rules in their Makefiles should lose, not be 
pampered by having make guess whether or not they meant to insert 
cd ${.CURDIR}.

> Anyway, the patch below teaches it to spot 'make -C somewhere' 
> as the equivalent of 'cd somewhere && make'.

... and to avoid the magic "cd ${.CURDIR}" that would have been 
added for most cases where ${MAKE} appeared as the first word in a 
command in the rules for a target.

> I limited the check of make args to some small number, since 
> I at least tend to make -C one of the 1st args, and it is 
> rare that an extra 'cd ${.CURDIR}' will do harm.  Setting 
> MAKE_CHECK_CWD_ARGS to 0 would check them all.

I don't like this.  The special case code is just to help people 
who write incorrect rules, so why optimise it for speed?  Either 
check all the args, or just remove the special code entirely.

--apb (Alan Barrett)