Re: [bitbake-devel] [PATCH 1/2] bitbake: data_smart: fix ??= operator for getVarFlags

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Wed, 2025-02-12 at 13:16 +0100, Louis Rannou via lists.openembedded.org wrote:
> From: Louis Rannou <louis.rannou@non.se.com>
> 
> Variable flags have been fixed in commit
> 0329a7e3ac694737f2d2c1861f65492551360663 which introduces the
> "_defaultval_flag_" prefix for default values. This must not be ignored as
> others "_"-prefixed flags names.
> 
> Split the processing of default values to be sure they are overwritted by the
> others operators disregarding of their order.
> 
> Fixes [YOCTO #15685]
> 
> Signed-off-by: Louis Rannou <louis.rannou@non.se.com>
> ---
>  lib/bb/data_smart.py | 16 +++++++++++++---
>  1 file changed, 13 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/bb/data_smart.py b/lib/bb/data_smart.py
> index 897ceeb32c7ce0acb8ed44c25e1bf2f2f28aa9dc..7663f28c5071a77c8452c1016e5ee0d969c84bec 100644
> --- a/lib/bb/data_smart.py
> +++ b/lib/bb/data_smart.py
> @@ -952,12 +952,22 @@ class DataSmart(MutableMapping):
>      def getVarFlags(self, var, expand = False, internalflags=False):
>          local_var = self._findVar(var)
>          flags = {}
> +        flags_set = {}
>  
>          if local_var:
> -            for i in local_var:
> -                if i.startswith(("_", ":")) and not internalflags:
> +            for i, val in local_var.items():
> +                if i.startswith("_defaultval_flag_"):
> +                    i = i[len("_defaultval_flag_"):]
> +                    flags[i] = val
> +                elif i.startswith(("_", ":")) and not internalflags:
>                      continue
> -                flags[i] = local_var[i]
> +                else:
> +                    flags_set[i] = val
> +
> +            # Flags sets take over defaults
> +            flags.update(flags_set)
> +
> +            for i in flags:
>                  if expand and i in expand:
>                      flags[i] = self.expand(flags[i], var + "[" + i + "]")
>          if len(flags) == 0:

I did spend more time looking at this and I had misunderstood the
problem. I think this can still be simplified though and I also suspect
the internalflags handling above isn't correct. If internalflags is
set, I think it probably should return _defaultval_flag_ values
unchanged. The code would therefore look more like:


for i, val in local_var.items():
    if i.startswith("_defaultval_flag_") and not internalflags:
        i = i[len("_defaultval_flag_"):]
        if i not in local_var:
            flags[i] = val
    elif i.startswith(("_", ":")) and not internalflags:
        continue
    else:
        flags_set[i] = val

I'd also add a comment to the test case explaining that we're testing
weak default make it to the getVarFlags output.

Cheers,

Richard