code review 5645093: cmd/dist: cross-compiling fixes

cmd/dist: cross-compiling fixes

This CL makes it possible to run make.bash with
GOOS and GOARCH set to something other than
the native host GOOS and GOARCH.

As part of the CL, the tool directory moves from bin/tool/
to pkg/tool/goos_goarch where goos and goarch are
the values for the host system (running the build), not
the target.  pkg/ is not technically appropriate, but C objects
are there now tool (pkg/obj/) so this puts all the generated
binaries in one place (rm -rf $GOROOT/pkg cleans everything).
Including goos_goarch in the name allows different systems
to share a single $GOROOT on a shared file system.

Fixes issue 2920.

[rsc, 2012-02-14 01:16:01]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[r, 2012-02-14 01:48:50]

i don't have a good countersuggestion but it bothers me that the goos_goarch
convention has a different meaning here than elsewhere. the other uses are where
you will be running; here it's where you're running now. it seems potentially
confusing.

but it probably doesn't matter; for the vast majority of cases those two setups
are the same.

[r, 2012-02-14 01:53:03]

LGTM

http://codereview.appspot.com/5645093/diff/8001/src/cmd/dist/build.c
File src/cmd/dist/build.c (right):

http://codereview.appspot.com/5645093/diff/8001/src/cmd/dist/build.c#newcode106
src/cmd/dist/build.c:106: if((i=find(gohostarch, okgoarch, nelem(okgoarch))) <
0)
split into two lines.

[rsc, 2012-02-14 03:31:54]

*** Submitted as http://code.google.com/p/go/source/detail?r=6c0e4bc626ee ***

cmd/dist: cross-compiling fixes

This CL makes it possible to run make.bash with
GOOS and GOARCH set to something other than
the native host GOOS and GOARCH.

As part of the CL, the tool directory moves from bin/tool/
to pkg/tool/goos_goarch where goos and goarch are
the values for the host system (running the build), not
the target.  pkg/ is not technically appropriate, but C objects
are there now tool (pkg/obj/) so this puts all the generated
binaries in one place (rm -rf $GOROOT/pkg cleans everything).
Including goos_goarch in the name allows different systems
to share a single $GOROOT on a shared file system.

Fixes issue 2920.

R=golang-dev, r
CC=golang-dev
http://codereview.appspot.com/5645093