Re: [Qemu-devel] [PATCH v2 5/6] qapi: generate list struct and visit_list for enum

[Luiz Capitulino]

On Sat,  2 Jun 2012 06:54:27 +0800
Amos Kong <address@hidden> wrote:

> Currently, if define an 'enum' and use it in one command's data,
> List struct for enum could not be generated, but it's used in
> qmp function.
> 
> For example: KeyCodesList could not be generated.
> >>> qapi-schema.json:
> { 'enum': 'KeyCodes',
>   'data': [ 'shift', 'alt' ... ] }
> { 'command': 'sendkey',
>   'data': { 'keys': ['KeyCodes'], '*hold-time': 'int' } }
> 
> >>> qmp-command.h:
> void qmp_sendkey(KeyCodesList * keys, bool has_hold_time, int64_t
> hold_time, Error **errp);
> 
> This patch makes qapi can generate List struct for enum.

This patch does it the simple way, just like any type. It generates a enum list
type and the functions qapi_free_yourenum() and qapi_free_yourenumlist().

The qapi_free_yourenum() list ends up doing nothing, so it could be a good
idea to generate an empty body (also note that we're copying the argument's
value, this could bite us in the future).

Another point I was wondering is that, all enums will end up having the
exact same code. So maybe we could generate a default int list and use it
for all enums. Not sure it's worth it though.

Michael, Paolo, ideas?

More review comments below.


> 
> Signed-off-by: Amos Kong <address@hidden>
> ---
>  scripts/qapi-types.py |   33 +++++++++++++++++++++++++++++----
>  scripts/qapi-visit.py |   14 +++++++++-----
>  2 files changed, 38 insertions(+), 9 deletions(-)
> 
> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
> index 4a734f5..c9641fb 100644
> --- a/scripts/qapi-types.py
> +++ b/scripts/qapi-types.py
> @@ -16,17 +16,36 @@ import os
>  import getopt
>  import errno
>  
> -def generate_fwd_struct(name, members):
> -    return mcgen('''
> +def generate_fwd_struct(name, members, enum=False):

I think it's better to have generate_fwd_enum_struct().

> +    ret = ""
> +    if not enum:
> +        ret += mcgen('''
>  typedef struct %(name)s %(name)s;
>  
> +''',
> +                     name=name)
> +    ret += mcgen('''
>  typedef struct %(name)sList
>  {
> -    %(name)s *value;
> +''',
> +                     name=name)
> +    if enum:
> +        ret += mcgen('''
> +         %(name)s value;
> +''',
> +                     name=name)
> +    else:
> +        ret += mcgen('''
> +         %(name)s * value;
> +''',
> +                     name=name)
> +
> +    ret += mcgen('''
>      struct %(name)sList *next;
>  } %(name)sList;
>  ''',
>                   name=name)
> +    return ret
>  
>  def generate_struct(structname, fieldname, members):
>      ret = mcgen('''
> @@ -265,7 +284,8 @@ for expr in exprs:
>      if expr.has_key('type'):
>          ret += generate_fwd_struct(expr['type'], expr['data'])
>      elif expr.has_key('enum'):
> -        ret += generate_enum(expr['enum'], expr['data'])
> +        ret += generate_enum(expr['enum'], expr['data']) + "\n"

The new-line should be returned by generate_enum(). Same applies for the
occurrences below.

> +        ret += generate_fwd_struct(expr['enum'], expr['data'], True)
>          fdef.write(generate_enum_lookup(expr['enum'], expr['data']))
>      elif expr.has_key('union'):
>          ret += generate_fwd_struct(expr['union'], expr['data']) + "\n"
> @@ -289,6 +309,11 @@ for expr in exprs:
>          fdef.write(generate_type_cleanup(expr['union'] + "List") + "\n")
>          ret += generate_type_cleanup_decl(expr['union'])
>          fdef.write(generate_type_cleanup(expr['union']) + "\n")
> +    elif expr.has_key('enum'):
> +        ret += generate_type_cleanup_decl(expr['enum'] + "List")
> +        fdef.write(generate_type_cleanup(expr['enum'] + "List") + "\n")
> +        ret += generate_type_cleanup_decl(expr['enum'])
> +        fdef.write(generate_type_cleanup(expr['enum']) + "\n")
>      else:
>          continue
>      fdecl.write(ret)
> diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
> index 8d4e94a..e44edfa 100644
> --- a/scripts/qapi-visit.py
> +++ b/scripts/qapi-visit.py
> @@ -81,7 +81,7 @@ end:
>  ''')
>      return ret
>  
> -def generate_visit_list(name, members):
> +def generate_visit_list(name, members, enum=False):
>      return mcgen('''
>  
>  void visit_type_%(name)sList(Visitor *m, %(name)sList ** obj, const char 
> *name, Error **errp)
> @@ -160,12 +160,14 @@ end:
>  
>      return ret
>  
> -def generate_declaration(name, members, genlist=True):
> -    ret = mcgen('''
> +def generate_declaration(name, members, genlist=True, enum=False):
> +    ret = ""
> +    if not enum:
> +        ret = mcgen('''
>  
>  void visit_type_%(name)s(Visitor *m, %(name)s ** obj, const char *name, 
> Error **errp);
>  ''',
> -                name=name)
> +                    name=name)

Why this change?

>  
>      if genlist:
>          ret += mcgen('''
> @@ -293,10 +295,12 @@ for expr in exprs:
>          ret += generate_declaration(expr['union'], expr['data'])
>          fdecl.write(ret)
>      elif expr.has_key('enum'):
> -        ret = generate_visit_enum(expr['enum'], expr['data'])
> +        ret = generate_visit_list(expr['enum'], expr['data'], True)
> +        ret += generate_visit_enum(expr['enum'], expr['data'])
>          fdef.write(ret)
>  
>          ret = generate_decl_enum(expr['enum'], expr['data'])
> +        ret += generate_declaration(expr['enum'], expr['data'], enum=True)
>          fdecl.write(ret)
>  
>  fdecl.write('''