Re: [Qemu-devel] [PATCH v10 08/25] qapi-types: Refactor base fields output

[Markus Armbruster <armbru@redhat.com>]

Eric Blake <eblake@redhat.com> writes:

> Move code from gen_union() into gen_struct_fields() in order for
> a later patch to share code when enumerating inherited fields
> for struct types.
>
> No change to generated code.
>
> Signed-off-by: Eric Blake <eblake@redhat.com>
>
> ---
> v10: new patch, split off of 5/17
> ---
>  scripts/qapi-types.py | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
>
> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
> index 4fe618e..a97cc10 100644
> --- a/scripts/qapi-types.py
> +++ b/scripts/qapi-types.py
> @@ -51,9 +51,19 @@ def gen_struct_field(name, typ, optional):
>      return ret
>
>
> -def gen_struct_fields(members):
> +def gen_struct_fields(members, base=None):
>      ret = ''
>
> +    if base:
> +        ret += mcgen('''
> +    /* Members inherited from %(c_name)s: */
> +''',
> +                     c_name=base.c_name())
> +        ret += gen_struct_fields(base.members)
> +        ret += mcgen('''
> +    /* Own members: */
> +''')
> +
>      for memb in members:
>          ret += gen_struct_field(memb.name, memb.type, memb.optional)
>      return ret
> @@ -126,14 +136,7 @@ struct %(c_name)s {
>  ''',
>                  c_name=c_name(name))
>      if base:
> -        ret += mcgen('''
> -    /* Members inherited from %(c_name)s: */
> -''',
> -                     c_name=c_name(base.name))
> -        ret += gen_struct_fields(base.members)
> -        ret += mcgen('''
> -    /* Own members: */
> -''')
> +        ret += gen_struct_fields([], base)
>      else:
>          ret += mcgen('''
>      %(c_type)s kind;

One baby step towards

    gen_struct_fields(members, base);

which is where we want both gen_struct() and gen_union() to go.

Slightly confusing: members are *local* members, while base.members are
*all* members.  But the same exists elsewhere already, so let's not
worry about it.

I kind of dislike gen_struct_fields() taking two parameters and calling
itself for one, but I guess we can reconsider after gen_struct() and
gen_union() are unified.  gen_struct_fields() might have just one caller
then.