Re: [Qemu-devel] [PATCH v2][ 09/21] qapi: add qapi-visit-core.h

[Anthony Liguori <aliguori@us.ibm.com>]

On 06/09/2011 10:14 AM, Luiz Capitulino wrote:
> On Fri,  3 Jun 2011 17:33:07 -0500
> Michael Roth<mdroth@linux.vnet.ibm.com>  wrote:
>
>> Base definitions/includes for Visiter interface used by generated
>> visiter/marshalling code.
>>
>> Signed-off-by: Michael Roth<mdroth@linux.vnet.ibm.com>
>> ---
>>   qapi/qapi-visit-core.h |  187 ++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 files changed, 187 insertions(+), 0 deletions(-)
>>   create mode 100644 qapi/qapi-visit-core.h
>>
>> diff --git a/qapi/qapi-visit-core.h b/qapi/qapi-visit-core.h
>> new file mode 100644
>> index 0000000..a5ba016
>> --- /dev/null
>> +++ b/qapi/qapi-visit-core.h
>> @@ -0,0 +1,187 @@
>> +/*
>> + * Core Definitions for QAPI Visiter Classes
>> + *
>> + * Copyright IBM, Corp. 2011
>> + *
>> + * Authors:
>> + *  Anthony Liguori<aliguori@us.ibm.com>
>> + *
>> + * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
>> + * See the COPYING.LIB file in the top-level directory.
>> + *
>> + */
>> +#ifndef QAPI_VISITER_CORE_H
>> +#define QAPI_VISITER_CORE_H
>> +
>> +#include "qapi/qapi-types-core.h"
>> +#include "error.h"
>> +#include<stdlib.h>
>> +
>> +typedef struct GenericList
>> +{
>> +    void *value;
>> +    struct GenericList *next;
>> +} GenericList;
>
> If there's a reason to not use our list API, it should be explained in
> the commit log.

Our lists require an embedded element.  Since these types are generated, 
if you want to use them in a different type of data structure, there's 
no easy way to add another embedded element.

The solution is to have non-embedded lists and that what this is.

Regards,

Anthony Liguori

>
>> +
>> +typedef struct Visiter Visiter;
>> +
>> +struct Visiter
>> +{
>> +    /* Must be set */
>> +    void (*start_struct)(Visiter *v, void **obj, const char *kind, const char *name, Error **errp);
>> +    void (*end_struct)(Visiter *v, Error **errp);
>> +
>> +    void (*start_list)(Visiter *v, const char *name, Error **errp);
>> +    GenericList *(*next_list)(Visiter *v, GenericList **list, Error **errp);
>> +    void (*end_list)(Visiter *v, Error **errp);
>> +
>> +    void (*type_enum)(Visiter *v, int *obj, const char *kind, const char *name, Error **errp);
>> +
>> +    void (*type_int)(Visiter *v, int64_t *obj, const char *name, Error **errp);
>> +    void (*type_bool)(Visiter *v, bool *obj, const char *name, Error **errp);
>> +    void (*type_str)(Visiter *v, char **obj, const char *name, Error **errp);
>> +    void (*type_number)(Visiter *v, double *obj, const char *name, Error **errp);
>> +
>> +    /* May be NULL */
>> +    void (*start_optional)(Visiter *v, bool *present, const char *name, Error **errp);
>> +    void (*end_optional)(Visiter *v, Error **errp);
>> +
>> +    void (*start_handle)(Visiter *v, void **obj, const char *kind, const char *name, Error **errp);
>> +    void (*end_handle)(Visiter *v, Error **errp);
>> +};
>> +
>> +static inline void visit_start_handle(Visiter *v, void **obj, const char *kind, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    if (v->start_handle) {
>> +        v->start_handle(v, obj, kind, name, errp);
>> +    }
>> +}
>
> IMO, all these inlines should be real functions and...
>
>> +
>> +static inline void visit_end_handle(Visiter *v, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    if (v->end_handle) {
>> +        v->end_handle(v, errp);
>> +    }
>> +}
>> +
>> +static inline void visit_start_struct(Visiter *v, void **obj, const char *kind, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->start_struct(v, obj, kind, name, errp);
>> +}
>
> ... this could be:
>
> if (!error_is_set(errp)) {
>      v->start_struct(v, obj, kind, name, errp);
> }
>
> Also valid for other functions in this file.
>
>> +
>> +static inline void visit_end_struct(Visiter *v, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->end_struct(v, errp);
>> +}
>> +
>> +static inline void visit_start_list(Visiter *v, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->start_list(v, name, errp);
>> +}
>> +
>> +static inline GenericList *visit_next_list(Visiter *v, GenericList **list, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return 0;
>> +    }
>> +
>> +    return v->next_list(v, list, errp);
>> +}
>> +
>> +static inline void visit_end_list(Visiter *v, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->end_list(v, errp);
>> +}
>> +
>> +static inline void visit_start_optional(Visiter *v, bool *present, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    if (v->start_optional) {
>> +        v->start_optional(v, present, name, errp);
>> +    }
>> +}
>> +
>> +static inline void visit_end_optional(Visiter *v, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    if (v->end_optional) {
>> +        v->end_optional(v, errp);
>> +    }
>> +}
>> +
>> +static inline void visit_type_enum(Visiter *v, int *obj, const char *kind, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->type_enum(v, obj, kind, name, errp);
>> +}
>> +
>> +static inline void visit_type_int(Visiter *v, int64_t *obj, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->type_int(v, obj, name, errp);
>> +}
>> +
>> +static inline void visit_type_bool(Visiter *v, bool *obj, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->type_bool(v, obj, name, errp);
>> +}
>> +
>> +static inline void visit_type_str(Visiter *v, char **obj, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->type_str(v, obj, name, errp);
>> +}
>> +
>> +static inline void visit_type_number(Visiter *v, double *obj, const char *name, Error **errp)
>> +{
>> +    if (error_is_set(errp)) {
>> +        return;
>> +    }
>> +
>> +    v->type_number(v, obj, name, errp);
>> +}
>> +
>> +#endif
>