[yocto] [PATCH] bb.build.addtask: add simple check for circular dependency

[Richard Purdie]

On Thu, 2019-01-17 at 19:15 +0100, Ulf Samuelsson wrote:
>  From 864e49bedbdab480c5ada9588ce8f980f23919dd Mon Sep 17 00:00:00
> 2001
> From: Ulf Samuelsson <ulf at emagii.com>
> Date: Thu, 17 Jan 2019 19:07:17 +0100
> Subject: [PATCH] bb.build.addtask: add simple check for circular
> dependency

We really can't hardcode a list of tasks like this in bitbake :(

The list is also incorrect (at a quick look its packagedata and
populate_sysroot is missing).

We'll need to come up with a better algorithm than this. From
experience with circular task dependencies within bitbake's runqueue,
this is a hard problem though.

Cheers,

Richard

> Signed-off-by: Ulf Samuelsson <ulf at emagii.com>
> ---
>   bitbake/lib/bb/build.py | 48 
> ++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 48 insertions(+)
> 
> diff --git a/bitbake/lib/bb/build.py b/bitbake/lib/bb/build.py
> index 3e2a94e..887ced1 100644
> --- a/bitbake/lib/bb/build.py
> +++ b/bitbake/lib/bb/build.py
> @@ -43,6 +43,25 @@ logger = logging.getLogger('BitBake.Build')
> 
>   __mtime_cache = {}
> 
> +KNOWN_TASKS = {
> +    'do_fetch' :           1 ,
> +    'do_unpack' :          2 ,
> +    'do_patch' :           3 ,
> +    'do_configure' :       4 ,
> +    'do_compile' :         5 ,
> +    'do_install' :         6 ,
> +    'do_package' :         7 ,
> +    'do_package_data' :    8 ,
> +    'do_rootfs' :          9 ,
> +    'do_image_qa' :       10 ,
> +    'do_image' :          11 ,
> +    'do_image_tar' :      12 ,
> +    'do_image_ubifs' :    12 ,
> +    'do_image_jffs2' :    12 ,
> +    'do_image_complete' : 13 ,
> +    'do_build' :          14
> +}
> +
>   def cached_mtime_noerror(f):
>       if f not in __mtime_cache:
>           try:
> @@ -820,7 +839,34 @@ def add_tasks(tasklist, d):
>       # don't assume holding a reference
>       d.setVar('_task_deps', task_deps)
> 
> +def circular(after, before):
> +    if after == None:
> +        return False
> +    if before == None:
> +        return False
> +    for a in after.split():
> +        if a in KNOWN_TASKS:
> +            for b in before.split():
> +                if a == b:
> +                    return True
> +                if b in KNOWN_TASKS:
> +                    if KNOWN_TASKS[b] < KNOWN_TASKS[a]:
> +                        return True
> +                    else:
> +                        # tasks OK
> +                        pass
> +                else:
> +                    # b is unknown
> +                    pass
> +        else:
> +            # a is unknown
> +            pass
> +
>   def addtask(task, before, after, d):
> +    if circular(after, before):
> +        logger.error("addtask: %s cannot be after %s and before %s"
> % 
> (task, after, before))
> +        raise
> +
>       if task[:3] != "do_":
>           task = "do_" + task
> 
> @@ -909,3 +955,5 @@ def tasksbetween(task_start, task_end, d):
>           chain.pop()
>       follow_chain(task_start, task_end)
>       return outtasks
> +
> +