Having do_rm_work depend on do_build had one major disadvantage:
do_build depends on the do_build of other recipes, to ensure that
runtime dependencies also get built. The effect is that when work on a
recipe is complete and it could get cleaned up, do_rm_work still
doesn't run because it waits for those other recipes, thus leading to
more temporary disk space usage than really needed.

The right solution is to inject do_rm_work before do_build and after
all tasks of the recipe. Achieving that depends on the new bitbake
bb.event.RecipeTaskPreProcess and bb.build.preceedtask().

It can't just run in an anonymous function, because other anonymous
functions that run later may add more tasks. There's still such a
potential conflict when some future RecipeTaskPreProcess event handler
also wants to change task dependencies, but that's not a problem
now. Should it ever occur, the two handlers will have to know about
each other and cooperate to resolve the conflict.

Benchmarking (see "rm_work + pybootchart enhancements" on the OE-core
mailing list) showed that builds with the modified rm_work.bbclass
were both faster (albeit not by much) and required considerably less
disk space (14230MiB instead of 18740MiB for core-image-sato).
Interestingly enough, builds with rm_work.bbclass were also faster
than those without.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

By default, do_rm_work either skips recipes entirely (when listed in
RM_WORK_EXCLUDE) or removes everything except for temp.

In meta-swupd, virtual image recipes collaborate on producing update
data for the base recipe. Tasks running in the base recipe need some
information from the virtual images.

Those files could be passed via a new shared work directory, but that
scatters data in even more places. It's simpler to use the normal
WORKDIR and teach rm_work.bbclass to not remove the special output
with the new RM_WORK_EXCLUDE_ITEMS.

Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

getVar() now defaults to expanding by default, thus remove the True
option from getVar() calls with a regex search and replace.

Search made with the following regex: getVar ?\(( ?[^,()]*), True\)

Signed-off-by: Joshua Lock <joshua.g.lock@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

We need to add do_write_qemuboot_conf to the list of tasks to be wiped as
otherwise the second time an image is built it will fail.

[ YOCTO #10758 ]

Signed-off-by: Ross Burton <ross.burton@intel.com>

We don't remove sigdata files, we also shouldn't remove sigbasedata files
as this hinders debugging.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

Excluded removal of do_bootimg, do_bootdirectdisk and do_vmimg
timestamps to prevent unneeded rootfs rebuilds.

[YOCTO #10159]

Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

As rm_work is just cleanup it shouldn't starve more important tasks such as
do_compile of I/O, so use BB_TASK_IONICE_LEVEL to run the task in the idle
scheduler class.

Signed-off-by: Ross Burton <ross.burton@intel.com>

* otherwise kernel is rebuilt every single time and often it fails when
  building external modules

[YOCTO #9352]

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

After the separation of do_rootfs, some rootfs references need changing
to image_complete.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

This prevents unneeded rootfs rebuilds if the metadata has not changed
while using rm_work.

Signed-off-by: Jate Sujjavanich <jatedev@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>