RTEMS examples build failed

[Chris Johns]

On 22/4/20 3:18 am, Gedare Bloom wrote:
> On Tue, Apr 21, 2020 at 8:42 AM Vijay Kumar Banerjee <vijay at rtems.org> wrote:
>>
>>
>>
>> On Tue, Apr 21, 2020 at 7:10 AM Chris Johns <chrisj at rtems.org> wrote:
>>>
>>> On 21/4/20 7:03 am, Vijay Kumar Banerjee wrote:
>>>> On Mon, Apr 20, 2020 at 11:33 PM Sebastian Huber
>>>> <sebastian.huber at embedded-brains.de
>>>> <mailto:sebastian.huber at embedded-brains.de>> wrote:
>>>>      We don't have to reinvent the wheel. We could copy the wscript of the
>>>>      new build system to the examples and add a couple of specification
>>>>      items. Building test programs is really not that much different to
>>>>      building applications.
>>>>
>>>> Just to make sure I understood correctly: Do you suggest that we replace
>>>> the rtems_waf in examples with the wscript similar to the new build system?
>>>
>> Hi,
>>>
>>> Please do not do this. I am reluctant to again head down the path of
>>> exposing the internals of the rtems.git build system to users via
>>> examples. It says to our users they need to use this approach to
>>> building RTEMS applications and that is not the case. It also removes
>>> the need for us to make sure we correctly handle exporting the needed
>>> build data for a BSP. I like the current separation.
>>>
>> Understood.
>>>
>>> I prefer the examples are just that, an example of code to use and how
>>> to build an application with different build systems. I welcome support
>>> for other build systems being added to our examples. It just needs
>>> someone to maintain whatever is added.
>>>
>>> The rtems_waf approach is based on the currently exported data and when
>>> a new build system is agreed on and merged it will be updated.
>>>
>>
>> I tried for some time to figure out some way to fix the dependency check errors
>> but couldn't find any other solution. I also tried building the whole source from
>> the build directory by adding this something like this:
>> ```
>>         rule = 'cp ${SRC} ${TGT}'
>>         bld (rule = rule, source = 'init.c', target = 'fat-root-init.c')
>> ```
>> This again works nicely with the build but gets stuck in the post run checks by
>> gccdeps that seems to search for the headers only in the source directory.
>>
>> Do you have some suggestions to try out? Patching the gccdeps works but
>> it seems like we don't want to do that (?)
>>
> 
> This was quite challenging for me to figure out how to make work the
> first time. I had to wade through the waf book to figure out how to
> make the generated header file visible. You might need to do some
> digging as well to see how it might be possible.

I will ask Thomas about this. I am currently busy else where and I hope 
to time to look at RTEMS things later this week.

> I think the next best solution is to have gccdeps search the build
> tree for the generated header file.
> 
> The worst solution is to touch an empty header file in the source tree.

It could be Thomas is OK with the gccdeps change, I am not sure.

Chris