Re: [Qemu-devel] [PATCH v4 11/29] typedefs: Separate incomplete types and function types

[Alex Bennée]

Markus Armbruster <address@hidden> writes:

> Markus Armbruster <address@hidden> writes:
>
>> Alex Bennée <address@hidden> writes:
>>
>>> Markus Armbruster <address@hidden> writes:
>>>
>>>> While there, drop the obsolete file comment.
>>>>
>>>> Signed-off-by: Markus Armbruster <address@hidden>
>>>> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
>>>> Tested-by: Philippe Mathieu-Daudé <address@hidden>
>>>> ---
>>>>  include/qemu/typedefs.h | 12 ++++++++----
>>>>  1 file changed, 8 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
>>>> index fcdaae58c4..29346648d4 100644
>>>> --- a/include/qemu/typedefs.h
>>>> +++ b/include/qemu/typedefs.h
>>>> @@ -1,10 +1,10 @@
>>>>  #ifndef QEMU_TYPEDEFS_H
>>>>  #define QEMU_TYPEDEFS_H
>>>>
>>>> -/* A load of opaque types so that device init declarations don't have to
>>>> -   pull in all the real definitions.  */
>>>> -
>>>> -/* Please keep this list in case-insensitive alphabetical order */
>>>> +/*
>>>> + * Incomplete struct types
>>>
>>> Maybe expand this a little...
>>>
>>>   "Incomplete struct types for modules that don't need the complete
>>>   definitions but still pass around typed variables."?
>>
>> If we explain proper use of qemu/typedefs.h in HACKING, as discussed in
>> review of v1[*], we could point there.
>
> Perhaps rewriting the obsolete file comment would be better.  Something
> like this:
>
>     /*
>      * This header is for selectively avoiding #include just to get a
>      * typedef name.
>      *
>      * Declaring a typedef name in its "obvious" place can result in
>      * inclusion cycles, in particular for complete struct and union
>      * types that need more types for their members.  It can also result
>      * in headers pulling in many more headers, slowing down builds.
>      *
>      * You can break such cycles and unwanted dependencies by declaring
>      * the typedef name here.
>      *
>      * For struct types used in only a few headers, judicious use of the
>      * struct tag instead of the typedef name is commonly preferable.
>      */
>
>     /*
>      * Incomplete struct types
>      * Please keep this list in case-insensitive alphabetical order.
>      */
>     typedef struct AdapterInfo AdapterInfo;
>     [...]
>
>     /*
>      * Pointer types
>      * Such typedefs should be limited to cases where the typedef's users
>      * are oblivious of its "pointer-ness".
>      * Please keep this list in case-insensitive alphabetical order.
>      */
>     typedef struct IRQState *qemu_irq;
>
>     /*
>      * Function types
>      */
>     typedef void SaveStateHandler(QEMUFile *f, void *opaque);
>     typedef int LoadStateHandler(QEMUFile *f, void *opaque, int version_id);
>     typedef void (*qemu_irq_handler)(void *opaque, int n, int level);
>
> What do you think?

A definite improvement on what is currently there ;-)

>
> [...]


--
Alex Bennée