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

[Amos Kong]

On 07/06/12 08:26, Michael Roth wrote:
> On Wed, Jun 06, 2012 at 03:40:37PM -0300, Luiz Capitulino wrote:
> > 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().
>
> Had a couple suggestions, but approach/patch seems reasonable to me.
>
> > 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).
>
> I think we can omit qapi_free_yourenum() completely. Humans will know
> not to free non-allocated types, and the generated marshallers
> don't use these interfaces.
>
> > 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.
>
> Since it's generated code I don't think it's worth it, personally.
>
> > Michael, Paolo, ideas?
> >
> > More review comments below.


Thanks for your review!

> > > 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().

I tried this before, too many duplicate codes would be introduced,
but it's more clear.

two functions need to be added
  qapi-types.py: def generate_fwd_enum_struct(name, members):
  qapi-visit.py: def generate_enum_declaration(name, members, 
genlist=True):

> > > +    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.


"\n" is used to add a blank line here.

> > > +        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?


Indent of above "mcgen(" changes, make them aligned.

> > >       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('''

--
                        Amos.