When Ctrl-C is pressed, just exited quietly. There is no sense in displaying
a stack trace since buildman will always be in the same place: waiting for
threads to complete building all the jobs on the queue.

Signed-off-by: Simon Glass <sjg@chromium.org>

This serves no real purpose, since when we are not active, we exit. Drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>

It is annoying that buildman does not respond cleanly to Ctrl-C or SIGINT,
particularly on machines with lots of CPUS. Unfortunately queue.join()
blocks the main thread and does not allow it to see the signal. Use a
separate thread instead,

Signed-off-by: Simon Glass <sjg@chromium.org>

Make it clear when buildman actually starts building. This happens when it
has prepared the threads, working directory and output directories.

Signed-off-by: Simon Glass <sjg@chromium.org>

When buildman starts, it prepares its output directory by removing any old
build directories which will not be used this time. This can happen if a
previous build left directories around for commit hashes which are no-longer
part of the branch.

This can take quite a while, so print a message to indicate what is going
on.

Signed-off-by: Simon Glass <sjg@chromium.org>

On a machine with a lot of CPUs this prints a lot of useless lines of the
form:

   Cloning repo for thread <n>

Adjust the output so that these all appear on one line, and disappear when
the cloning is complete.

Note: This cloning is actually unnecessary and very wasteful on disk space
(about 3.5GB each time). It would be better to create symlinks.

Signed-off-by: Simon Glass <sjg@chromium.org>

One use-case for buildman is to continually run it interactively after
each small step in a large refactoring operation. This gives more
immediate feedback than making a number of commits and then going back and
testing them. For this to work well, buildman needs to be extremely fast.
At present, a couple issues prevent it being as fast as it could be:

1) Each time buildman runs "make %_defconfig", it runs "make mrproper"
first. This throws away all previous build results, requiring a
from-scratch build. Optionally avoiding this would speed up the build, at
the cost of potentially causing or missing some build issues.

2) A build tree is created per thread rather than per board. When a thread
switches between building different boards, this often causes many files
to be rebuilt due to changing config options. Using a separate build tree
for each board would avoid this. This does put more strain on the system's
disk cache, but it is worth it on my system at least.

This commit adds two command-line options to implement the changes
described above; -I ("--incremental") turns of "make mrproper" and -P
("--per-board-out-dir") creats a build directory per board rather than per
thread.

Tested:

    ./tools/buildman/buildman.py tegra
    ./tools/buildman/buildman.py -I -P tegra
    ./tools/buildman/buildman.py -b tegra_dev tegra
    ./tools/buildman/buildman.py -b tegra_dev -I -P tegra

... each once after deleting the buildman result/work directory, and once
"incrementally" after a previous identical invocation.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Simon Glass <sjg@chromium.org> # v1
Tested-by: Simon Glass <sjg@chromium.org> # v1
Acked-by: Simon Glass <sjg@chromium.org>

At present buildman can compare configurations between commits but the
feature is less useful than it could be. There is no summary by architecture
and changes are not reported on a per-board basis.

Correct these deficiencies so that it is possible to see exactly what is
changing for any number of boards.

Note that 'buildman -b <branch> -C' is recommended for any build where you
will be comparing configuration. Without -C the correct configuration will
not be reported since changes will often not be picked up.

Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

It is useful to be able to see CONFIG changes made by commits. Add this
feature to buildman using the -K flag so that all CONFIG changes are
reported.

The CONFIG options exist in a number of files. Each is reported
individually as well as a summary that covers all files. The output
shows three parts: green for additions, red for removals and yellow for
changes.

Signed-off-by: Simon Glass <sjg@chromium.org>

When a verbose build it selected, show the make command before the output of
that command.

Signed-off-by: Simon Glass <sjg@chromium.org>