[PATCH] Avoid StopIteration exception for non-rtems .pc

[Chris Johns]

Hi Martin,

Thanks for posting the patch. I have pushed it. I have pushed an update after
running the change through yapf. I forgot to do that before pushing.

I will also add a new function to the rtems module as a separate patch:

+def arch_bsp(ctx):
+    """ Return the list of arch/bsps we are building."""
+    return ctx.env.ARCH_BSP
+
+

I think it would be good to update all the submodules.

On 5/10/2023 11:40 pm, Martin Erik Werner wrote:
> _arch_from_arch_bsp() and _bsp_from_arch_bsp() has overly optimistic
> assumptions that the argument must contain a '-'-separated field which
> starts with "rtems". These functions are intended to find the target
> triplet or the bsp parts of strings like "sparc-gaisler-rtems5-leon3"
> and "arm-rtems6-xilinx_zynq_zc702"

Yes the interface around arch/bsp is a bit average and I have wondered about a
change but I think the interface is now set and I think it is too late to change.

> But _find_installed_arch_bsps() may call _arch_from_arch_bsp() with the
> name (without file extension) of any file which ends with ".pc",
> including for example "expat". This triggers a StopIteration exception
> when trying to find the next field after the "rtems" field, since no
> "rtems" field exists to start with.
> 
> Rework these function to remove the preconditions, so that they return
> None if no "rtems" field exist or if no field exists before or after the
> "rtems" field.

Nice.

> It could be argued. based on their name, that calling these functions
> with something that is not a triplet-bsp string is incorrect to start
> with, but attempting to address that is not done here.

Yes I agree and I also think we need to accept the string in this case.

Chris

> ---
> 
> This should fix the issue discovered by David Siddons and Frank Kühndel
> described in the "build failed" thread from 2023-07-23 in the
> rtems-users mailing list with message-id:
> <8e6c2841-ae9e-aacf-de84-e6340d20456a at embedded-brains.de>
> 
> I have tested this fix when compiling the simple quickstart application
> for the sparc-gaisler-rtems5-leon3 and arm-rtems6-xilinx_zynq_zc702
> targets, but I have not verified execution of the build results, this is
> probably the amount of testing that I will be able to perform at the
> moment.
> 
>  rtems.py | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/rtems.py b/rtems.py
> index c65a7d2..a29d281 100644
> --- a/rtems.py
> +++ b/rtems.py
> @@ -859,15 +859,17 @@ def _check_arch_bsps(req, config, path, archs, version):
>  
>  def _arch_from_arch_bsp(arch_bsp):
>      fields = arch_bsp.split('-')
> -    rtems_field_index = next(i for i, field in enumerate(fields) if field.startswith('rtems'))
> -    return '-'.join(fields[:(rtems_field_index + 1)])
> -
> +    for i, field in enumerate(fields):
> +        if field.startswith('rtems') and fields[:(i + 1)] is not None:
> +            return '-'.join(fields[:(i + 1)])
> +    return None
>  
>  def _bsp_from_arch_bsp(arch_bsp):
>      fields = arch_bsp.split('-')
> -    rtems_field_index = next(i for i, field in enumerate(fields) if field.startswith('rtems'))
> -    return '-'.join(fields[(rtems_field_index + 1):])
> -
> +    for i, field in enumerate(fields):
> +        if field.startswith('rtems') and fields[(i + 1):] is not None:
> +            return '-'.join(fields[(i + 1):])
> +    return None
>  
>  def _pkgconfig_path(path):
>      return os.path.join(path, 'lib', 'pkgconfig')