RTEMS examples build failed

[Sebastian Huber]

On 20/04/2020 19:04, Vijay Kumar Banerjee wrote:

> On Sun, Apr 19, 2020 at 8:16 PM Sebastian Huber 
> <sebastian.huber at embedded-brains.de 
> <mailto:sebastian.huber at embedded-brains.de>> wrote:
>
>     On 19/04/2020 15:38, Gedare Bloom wrote:
>
>>     On Sun, Apr 19, 2020 at 3:52 AM Vijay Kumar Banerjee<vijay at rtems.org>  <mailto:vijay at rtems.org>  wrote:
>>>     Hi,
>>>
>>>     While trying to build the examples with a fresh pull from upstream,
>>>     I got the following build error from gccdeps:
>>>
>>>     ```
>>>     Build failed
>>>     Traceback (most recent call last):
>>>        File "//home/lunatic/development/rtems-examples//.waf-2.0.19-1f3c580272b15a03d2566843c5fe872a/waflib/Task.py", line 190, in process
>>>          self.post_run()
>>>        File "/home/lunatic/development/rtems-examples/rtems_waf/gccdeps.py", line 144, in post_run
>>>          raise ValueError('could not find %r for %r' % (x, self))
>>>     ValueError: could not find ['filesystem', 'fat_ramdisk', 'fs-root-tar.h'] for
>>     It's doing an error check to find the build dependency fs-root-tar.h,
>>     which gets generated in the build directory by bin2c. This has always
>>     been tricky to handle in waf. I don't grok the way Chris reworked the
>>     rootfs support in the example so I don't immediately see the root
>>     (hah) problem or how to try to fix it.
>
>
> Hi,
>
> I figured out that the tar is generating properly but the error check 
> is failing
> because it's looking for the fs-root-tar.h file in the source file 
> directory but the
> header file is being generated in the build directory.
>
> Just manually copying the header file to the source directory makes it 
> happy
> and the build works fine. Do we want to generate the header file in 
> the source
> directory as well and maybe add it in gitignore?
>
> The other approach can be to tell gccdeps to check for the files in 
> the build
> directory instead. I did it with a workaround like the following, and 
> it works fine:
> ```
> diff --git a/gccdeps.py b/gccdeps.py
> index bfabe72..61d9bfd 100644
> --- a/gccdeps.py
> +++ b/gccdeps.py
> @@ -141,7 +141,10 @@ def post_run(self):
>                         node = path_to_node(path, x, cached_nodes)
>
>                 if not node:
> -                       raise ValueError('could not find %r for %r' % 
> (x, self))
> +                       x = 
> os.path.relpath(str(bld.bldnode)).split('/') + x
> +                       node = path_to_node(path, x, cached_nodes)
> +                       if not node:
> +                           raise ValueError('could not find %r for 
> %r' % (x, self))
>                 if id(node) == id(self.inputs[0]):
>                         # ignore the source file, it is already in the 
> dependencies
>                         # this way, successful config tests may be 
> retrieved from the cache
> ```
>
> If it doesn't look too hackish, then I'll post a patch. This shouldn't 
> break anything else
> and I'll surely add comments there about the use case of taking this 
> approach.
>
> Does it look right?
I encountered the same error while writing the new build system. I think 
this issue can be fixed with a proper dependency chain in waf. Patching 
the generic gccdeps.py is not the way to go if you ask me.