Date: Thu, 27 Jun 1996 16:40:11 -0700 From: Scott Blachowicz <scott@statsci.com> To: "Jordan K. Hubbard" <jkh@time.cdrom.com> Cc: Nate Williams <nate@mt.sri.com>, current@FreeBSD.org Subject: Re: Building inside of /usr/src? Message-ID: <m0uZQfT-0005zuC@main.statsci.com> In-Reply-To: Your message of "Thu, 27 Jun 1996 15:31:49 -0700." <7235.835914709@time.cdrom.com> References: <7235.835914709@time.cdrom.com>
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"Jordan K. Hubbard" <jkh@time.cdrom.com> wrote:
> The only thing I can figure out was that someone found AMD's path
> mangling to be non-intuitive (though functional) or something and
> figured they'd substitite in the value of $PWD. I can think of no
> other reason for it
It is extra information which, if valid, gives an idea of how the user of
the makefile views the world/file systems around. Chances are that, if an
automounter is used and $PWD does indeed point to the current directory,
that $PWD represents the "normal" way to get to the current directory. If
there are other parallel directories controlled via the same amd
mountpoint, that can be useful information since the directories are
mounted into a different hierarchy.
How's this one sound, for example...say I have an amd-controlled mount
point called "/sw" with some entries like this:
src -sublink:=src \
host!=server1;rhost:=server1;rfs:=/export \
host==server1;type:=link;fs:=/export
bin -sublink:=bin.${arch} \
host!=server1;rhost:=server1;rfs:=/export \
host==server1;type:=link;fs:=/export
lib -sublink:=lib \
host!=server1;rhost:=server1;rfs:=/export \
host==server1;type:=link;fs:=/export
#...etc...
If I cd to /sw/src and do a make, the top level make sets a ${SRCDIR}
variable to the current directory, then sets ${BINDIR}, ${LIBDIR}
variables based on that directory. Going into ${LIBDIR} would fall over
if it is set to /a/server1/sw/lib (since it might not be there if amd
hasn't mounted it there yet), but not if it set to /sw/lib...or something
like that.
Yes, I know that's not a good behavior to rely on and if it is diagnosed
could be worked around by saying 'make SRCDIR=/sw/src' and the author of
the make files could probably robustify them a bit, but it behavioral
change introduced by the current change to the make program.
I don't know how long that particular bit of logic has been in there (for
people to get used to/rely on) and who put it there (what were the reasons
and benefits). So, I don't have enough info to gauge its importance, but
it IS a change from current behavior that could (possibly) be avoided by
just grabbing /bin/pwd output directly (or introducing a different C code
path that is explicitly invoked by these makefiles). I'm not familiar with
bmake files, their usage in *BSD 'make world's, etc...
Scott Blachowicz Ph: 206/283-8802x240 Mathsoft (Data Analysis Products Div)
1700 Westlake Ave N #500
scott@statsci.com Seattle, WA USA 98109
Scott.Blachowicz@seaslug.org
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