[PATCH v2] elf: Fix tst-relro-symbols.py argument passing

[Florian Weimer]

* Adhemerval Zanella:

> Current scheme only consideres the first argument for both --required
> and --optional, where the idea is to append a new item.
>
> Checked on x86_64-linux-gnu.
> ---
>  elf/tst-relro-symbols.py | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/elf/tst-relro-symbols.py b/elf/tst-relro-symbols.py
> index 368ea3349f..a572a47148 100644
> --- a/elf/tst-relro-symbols.py
> +++ b/elf/tst-relro-symbols.py
> @@ -56,10 +56,10 @@ def get_parser():
>      """Return an argument parser for this script."""
>      parser = argparse.ArgumentParser(description=__doc__)
>      parser.add_argument('object', help='path to object file to check')
> -    parser.add_argument('--required', metavar='NAME', default=(),
> -                        help='required symbol names', nargs='*')
> -    parser.add_argument('--optional', metavar='NAME', default=(),
> -                        help='required symbol names', nargs='*')
> +    parser.add_argument('--required', metavar='NAME', action='append', default=[],
> +                        help='required symbol names')
> +    parser.add_argument('--optional', metavar='NAME', action='append', default=[],

Nit: Like length limit exceeded.

> +                        help='required symbol names')
>      return parser
>  
>  def main(argv):

Despite the use of [] here, there does not seem to be a sharing hazard:

import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--foo', action='append', default=[])
print(parser.parse_args('--foo 1 --foo 2'.split()))
print(parser.parse_args('--foo 3 --foo 4'.split()))

Prints:

Namespace(foo=['1', '2'])
Namespace(foo=['3', '4'])

I would have expected:

Namespace(foo=['1', '2'])
Namespace(foo=['1', '2', '3', '4'])

Either way, given that the parser is only used once, that doesn't really
matter.  So we can implement it this way even though the documentation
is ambiguous.

Reviewed-by: Florian Weimer <fweimer@redhat.com>

Thanks,
Florian