[Libreoffice] Tinderbox 2.0 what I've got so far...

So, finally found some time to work on the tinbuld script... I pushed
what I've done so far, even though it is not completely operational
yet...
but it is close enough that it is worth having fresh eyes on it...

Note: none of what I did should impact the existing tinbuild script,
therefore it should not break any existing setup you have

this is the content of the README.tinbuild2, that I hope explain
reasonably well enough what I am going for:

=============

tinbuild2 is an evolution of tinbuild....
Warning: this work is not fully operational yet

Why:

The main motivation was the need to have a more flexible customisation for the
different build step. For performance reason, I needed to be able to set-up a
ram_disk after the make clean, create a bunch of directory and link them in
the tree to preempt solver and all the *.pro build directory

I also needed a pre-clean step to be able to destroy that ram_disk (hence
speeding up the make clean a lot)


so rather than hacking the existing tinbuild in a way I could never upstream
I started tinbuild2.

while at it, I set-up a few more goals:
have the list of commits and committers - in case of failure - be generated
based on the heads of the last sucessful build, rather than based on a
timestamp. this is needed because the timestamp associated to the commits
have little correlation to the time when they have become available in the
public tree.
Working based on a set of heads, meant I also wanted to tinbuild to be
'restartable'. in other words, if the tinbuild stop of any reason
(Ctrl-C for instance). when it restart it will behave as if it was stopped
just after the last successful build it did.
This require to prime/bootstrap the tinbuild, that is to successfully complete a
build sequence. this is achieved with running it once with -b.
It will then attempt a build iteration (without pulling) and stop immediately
after that.


How:

The design is loosely inspired from Gentoo's portage. the idea is to use
the ability of bash to redefine function.

so the function to build the product, do_build, is implemented with

tb_call()
{
        declare -F "$1" > /dev/null && $1
}

phase()
{
        local f=${1}
        for x in {pre_,do_,_post}${f} ; do
                tb_call ${x}
        done
}


do_build()
{
        retval=0
        for p in autogen clean make test push ; do
        echo "call $p"
                phase $p
        done
}

so essentially the following functions will be called if implemented
pre_autogen, do_autogen, post_autogen, pre_clean, do_clean, post_clean,
pre_make, do_make, post_make, pre_test, do_test, post_test, pre_push, do_push,
post_push

Note that the implementation of these function need to test ${retval} to find
out if a step before them had failed. if so they may decide to do nothing
(most cases) or may decide to still do something.
reciprocally, every function should put a non-zero value in retval in case of
failure.

Now, the base function are implemented in tinbuild_phases.sh
but these function can be overrided by a user-implementation.

In the same spirit, platform dependent hack can be done in
tinbuild_internals_<uname>.sh
The core default is meant to run on Linux, using bash and all the GNU tools that
are expected to normally be there on a Linux box.
Other platform will re-implementent incompatible stuff in theyre own .sh

And yes. bash is required. There maybe a way to avoid it, but:
1/ Bash is required to build the product anyway
2/ VHS won over BetaMax, get over it :-)


Where:

tinbuild2 rely on a profile name, passed with a mandatory -p <name> on the
command line.
That name is used to locate a file in ~/.tinbuild/config/<name>.cfg
(you have to create it)

That config file should contain all the needed SMTP information,
the name of you build (TINDER_NAME)  and
can override factory default (like PAUSE_SECOND, which by default
is set at 15 minutes (900 seconds))

also, if present, the file ~/.tinbuild/phases/<name>.sh will be sourced
after tinbuild_phases.sh.
This allow to override and/or expand the default build behavior.

Note that there is no 'inheritance'. if you override and existing function
you cannot invoke it anymore. so you cannot 'expand' a function, just
re-write you own implementation of it.


TODO:

* In order not to mess the tinderbuild server with crappy message while
debuggin tinbuild2, I have disabled the mail-sending part of it.
(which means that that code as not run at all and is likely to have
stupid bugs in it)

* There should be an effort to refine the naming of things:
of the config variables to keep the gobal namespace sane
(like having TB_ as a prefix for these)

* There should be an effort to document the available API
that is the functions and variable available to the phases
functions. like how to send an email, how to manipulate dates
etc...

* write a proper 'user guide'


Future:

* make the locking mechanism work for Mac (flock is missing)
* make one tinbuild able to handle more than one branch based on the same repo
* make the pushing of result packages asynchronous.
* make tinbuild respond to a pipe or a socket to be able to dynamically feed him
  one-time request to do a build on a feature-branch (in that case there won't
  be a baseline and the result, what-ever it is will be send to the 'requestor'