Re: MKREPRO: what variable contains the actual obj directory?

[christos%astron.com@localhost (Christos Zoulas)]

In article <alpine.NEB.2.11.1601071727540.930%galant.ogmig.net@localhost>,
Iain Hibbert  <plunky%ogmig.net@localhost> wrote:
>On Thu, 7 Jan 2016, Thomas Klausner wrote:
>
>> On Thu, Jan 07, 2016 at 04:35:44PM +0000, Iain Hibbert wrote:
>> > On Thu, 7 Jan 2016, Thomas Klausner wrote:
>> > 
>> > > For reproducible builds, the binaries should be the same independent
>> > > of the paths where the source or object directories live.
>> > > 
>> > > There are patches available for gcc to fix the paths (i.e., replace
>> > > the obj directory that is actually used in a build with a fixed
>> > > string, e.g. /usr/obj).
>> > > 
>> > > However, with the gazillion options we have in share/mk for choosing
>> > > object directories, I don't know what variable contains the actual
>> > > object directory that is used during a build.
>> > > 
>> > > Can someone shed a light on this?
>> > 
>> > Ah, its somewhat complex :)
>> > 
>> > see section of bsd.obj.mk in bsd.README
>> 
>> Yes, I saw that. That's why I'm asking (and hoping) that there is a
>> variable which gives me the final path to foo.o. Is there such a thing?
>
>perhaps .OBJDIR ?
>
>% cd src/usr.bin/make
>% make -V .OBJDIR
>/home/plunky/src/usr.bin/make
>% mkdir obj
>% make -V .OBJDIR
>/home/plunky/src/usr.bin/make/obj
>% mkdir obj.i386
>% make -V .OBJDIR
>/home/plunky/src/usr.bin/make/obj.i386

1. Why does MKREPRO need to know about OBJDIR?
2. Where is OBJDIR stored in the build artifacts and why?
3. Even if we find and substitute $OBJDIR with something fixed, won't
   that cause problems because we can build with and without
   object directories?

christos

christos