In article <20050621033916.GF5900@mewburn.net>,
Luke Mewburn  <lukem@NetBSD.org> wrote:
>-=-=-=-=-=-
>
>As recently observed in another discussion on this list,
>make(1) has "special" inbuilt .OBJDIR handling.
>
>To recap, the inbuilt-to-make .OBJDIR rules are:
>
>    	if MAKEOBJDIRPREFIX is set in the environment		# rule 1
>		.OBJDIR = ${MAKEOBJDIRPREFIX}/${PWD}
>	else MAKEOBJDIR is set in the environment		# rule 2
>			# MAKEOBJDIR may be an expression
>		.OBJDIR = ${MAKEOBJDIR}
>	else if -d "obj.${MACHINE}"				# rule 3
>		.OBJDIR = obj.${MACHINE}
>	else if -d "obj"					# rule 4
>		.OBJDIR = obj
>	else if -d "/usr/obj/${PWD}"				# rule 5
>		.OBJDIR = /usr/obj/${PWD}
>	else							# rule 6
>		.OBJDIR = .CURDIR
>
>I personally believe that rules 3 through 5 should be removed from make.
>Rationale:
>
>    *	They're not documented in make(1)'s manual page.
>
>    *	They cause enormous confusion when building programs without
>	MAKEOBJDIR or MAKEOBJDIRPREFIX, especially programs outside
>	of the "standard" NetBSD source tree, that have:
>	    -	a subdirectory called "obj",
>	    -	a subdirectory called "obj.`uname -n`"
>		(although that's less likely), or
>	    -	a directory in /usr/obj/`pwd`
>
>It has been suggested to me privately that we could add another
>special target to control this behaviour, but I'm not convinced
>we need it; "standard" NetBSD builds already have support in
><bsd.own.mk> for this magic objdir handling.
>
>(I'd argue we cull this magic from bsd.obj.mk as well but
>that's a separate discussion.)
>
>
>This change would simplify the .OBJDIR handling in make(1) to:
>
>    	if MAKEOBJDIRPREFIX is set in the environment		# rule 1
>		.OBJDIR = ${MAKEOBJDIRPREFIX}/${PWD}
>	else MAKEOBJDIR is set in the environment		# rule 2
>			# MAKEOBJDIR may be an expression
>		.OBJDIR = ${MAKEOBJDIR}
>	else							# rule 3
>		.OBJDIR = .CURDIR
>
>Of course, a Makefile is still free to override .OBJDIR if it wants to.
>
>
>
>This would solve a bunch of complaints users have raised,
>allow us to use our (NetBSD) make for some packages which
>currently use GNU make to avoid the "obj" subdir .OBJDIR frobbery,
>and result in less effort required to modify make(1)'s manual
>page to match reality.
>
>
>Comments?

Yes, just do it. Less magic == more sane.

christos