Re: [Qemu-devel] [PATCH 02/18] qapi-types.py: Implement 'base' for unions

[Amos Kong]

On Tue, Jul 23, 2013 at 03:03:10PM +0200, Kevin Wolf wrote:
> The new 'base' key in a union definition refers to a struct type, which
> is inlined into the union definition and can represent fields common to
> all kinds.
> 
> For example the following schema definition...
> 
>     { 'type': 'BlockOptionsBase', 'data': { 'read-only': 'bool' } }
> 
>     { 'union': 'BlockOptions',
>       'base': 'BlockOptionsBase',
>       'data': {
>           'raw': 'BlockOptionsRaw'
>           'qcow2': 'BlockOptionsQcow2'
>       } }
> 
> ...would result in this generated C struct:
> 
>     struct BlockOptions
>     {
>         BlockOptionsKind kind;
>         union {
>             void *data;
>             BlockOptionsRaw * raw;
>             BlockOptionsQcow2 * qcow2;
>         };
>         bool read_only;
>     };
> 
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  scripts/qapi-types.py | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
> index e1239e1..9882b95 100644
> --- a/scripts/qapi-types.py
> +++ b/scripts/qapi-types.py
> @@ -157,7 +157,12 @@ typedef enum %(name)s
>  
>      return lookup_decl + enum_decl
>  
> -def generate_union(name, typeinfo):
> +def generate_union(expr):
> +
> +    name = expr['union']
> +    typeinfo = expr['data']
> +    base = expr.get('base')
> +
>      ret = mcgen('''
>  struct %(name)s
>  {
> @@ -176,6 +181,13 @@ struct %(name)s
>  
>      ret += mcgen('''
>      };
> +''')
> +
> +    if base:
> +        struct = find_struct(base)
> +        ret += generate_struct_fields(struct['data'])


generate_struct_fields() doesn't exist in upstream.

[qemu-upstream]$ grep generate_struct_fields -r *
scripts/qapi-types.py:        ret += generate_struct_fields(struct['data'])
[qemu-upstream]$


> +
> +    ret += mcgen('''
>  };
>  ''')
>  
> @@ -359,7 +371,7 @@ for expr in exprs:
>          ret += generate_type_cleanup_decl(expr['type'])
>          fdef.write(generate_type_cleanup(expr['type']) + "\n")
>      elif expr.has_key('union'):
> -        ret += generate_union(expr['union'], expr['data'])
> +        ret += generate_union(expr)
>          ret += generate_type_cleanup_decl(expr['union'] + "List")
>          fdef.write(generate_type_cleanup(expr['union'] + "List") + "\n")
>          ret += generate_type_cleanup_decl(expr['union'])
> -- 
> 1.8.1.4
> 

-- 
                        Amos.