[PATCH rtems_waf] rtems: Add uninstall option to the list of commands

[Chris Johns]

On 4/5/20 8:16 pm, Vijay Kumar Banerjee wrote:
> 
> 
> On Mon, May 4, 2020 at 4:39 AM Chris Johns <chrisj at rtems.org 
> <mailto:chrisj at rtems.org>> wrote:
> 
>     Hi
> 
>     Are uninstall command useful with RTEMS? A use case that shows how it
>     would be used may help.
> 
> The use case in mind was libbsd. The uninstall command comes handy in
> cleaning off the files that were installed, and there's no need to delete it
> manually. I remember having some issues with libbsd while taking a trial
> and error approach in searching for the right sources, the residue of the
> old build would often cause problems and I had to delete them manually.

I understand. I see this as a development issue and not something a user 
would typically do. A release can have the pieces in a vertically 
software stack built on top of each other, i.e. a single prefix. For 
development where you can have specific pieces that are moving relative 
to each other I recommend separate sandboxing. The user manual details 
this. Prefix based sandboxing lets you remove a specific prefix without 
needing to rebuild the whole stack.

>     I use separate prefixes to manage this. We do not track common files
>     when installing to a common prefix so building ARM and then PowerPC to
>     the same prefix then uninstalling only the PowerPC build would remove
>     files needed by ARM.
> 
> waf only removes the files that have been installed with install_files. If I
> run ./waf uninstall from libbsd, only the files under 
> arm-rtems5/beagleboneblack/lib
> are getting affected.

That must be the default uninstall for waf. We should decide to move one 
way or the other, that is remove the uninstall because it is broken or 
we fix it, i.e. your patch?

I hesitate adding something that is not manually tested often and so not 
kept up to date. Would a unit test be a solution? Something that 
collects a hash based stamp for all the files under a prefix, performs 
the install and the uninstall steps and then verifies the prefix tree is 
exactly the same?

Chris