xref: /openbmc/qemu/include/qapi/visitor.h (revision 39de9984)
1 /*
2  * Core Definitions for QAPI Visitor Classes
3  *
4  * Copyright (C) 2012-2016 Red Hat, Inc.
5  * Copyright IBM, Corp. 2011
6  *
7  * Authors:
8  *  Anthony Liguori   <aliguori@us.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
11  * See the COPYING.LIB file in the top-level directory.
12  *
13  */
14 #ifndef QAPI_VISITOR_CORE_H
15 #define QAPI_VISITOR_CORE_H
16 
17 #include "qemu/typedefs.h"
18 #include "qapi/qmp/qobject.h"
19 #include "qapi/error.h"
20 #include <stdlib.h>
21 
22 /* This struct is layout-compatible with all other *List structs
23  * created by the qapi generator.  It is used as a typical
24  * singly-linked list. */
25 typedef struct GenericList {
26     struct GenericList *next;
27     char padding[];
28 } GenericList;
29 
30 /* This struct is layout-compatible with all Alternate types
31  * created by the qapi generator. */
32 typedef struct GenericAlternate {
33     QType type;
34     char padding[];
35 } GenericAlternate;
36 
37 void visit_start_struct(Visitor *v, const char *name, void **obj,
38                         size_t size, Error **errp);
39 void visit_end_struct(Visitor *v, Error **errp);
40 
41 void visit_start_list(Visitor *v, const char *name, Error **errp);
42 GenericList *visit_next_list(Visitor *v, GenericList **list, size_t size);
43 void visit_end_list(Visitor *v);
44 
45 /*
46  * Start the visit of an alternate @obj with the given @size.
47  *
48  * @name specifies the relationship to the containing struct (ignored
49  * for a top level visit, the name of the key if this alternate is
50  * part of an object, or NULL if this alternate is part of a list).
51  *
52  * @obj must not be NULL. Input visitors will allocate @obj and
53  * determine the qtype of the next thing to be visited, stored in
54  * (*@obj)->type.  Other visitors will leave @obj unchanged.
55  *
56  * If @promote_int, treat integers as QTYPE_FLOAT.
57  *
58  * If successful, this must be paired with visit_end_alternate(), even
59  * if visiting the contents of the alternate fails.
60  */
61 void visit_start_alternate(Visitor *v, const char *name,
62                            GenericAlternate **obj, size_t size,
63                            bool promote_int, Error **errp);
64 
65 /*
66  * Finish visiting an alternate type.
67  *
68  * Must be called after a successful visit_start_alternate(), even if
69  * an error occurred in the meantime.
70  *
71  * TODO: Should all the visit_end_* interfaces take obj parameter, so
72  * that dealloc visitor need not track what was passed in visit_start?
73  */
74 void visit_end_alternate(Visitor *v);
75 
76 /**
77  * Check if an optional member @name of an object needs visiting.
78  * For input visitors, set *@present according to whether the
79  * corresponding visit_type_*() needs calling; for other visitors,
80  * leave *@present unchanged.  Return *@present for convenience.
81  */
82 bool visit_optional(Visitor *v, const char *name, bool *present);
83 
84 void visit_type_enum(Visitor *v, const char *name, int *obj,
85                      const char *const strings[], Error **errp);
86 void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp);
87 void visit_type_uint8(Visitor *v, const char *name, uint8_t *obj,
88                       Error **errp);
89 void visit_type_uint16(Visitor *v, const char *name, uint16_t *obj,
90                        Error **errp);
91 void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
92                        Error **errp);
93 void visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
94                        Error **errp);
95 void visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp);
96 void visit_type_int16(Visitor *v, const char *name, int16_t *obj,
97                       Error **errp);
98 void visit_type_int32(Visitor *v, const char *name, int32_t *obj,
99                       Error **errp);
100 void visit_type_int64(Visitor *v, const char *name, int64_t *obj,
101                       Error **errp);
102 void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
103                      Error **errp);
104 void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp);
105 void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp);
106 void visit_type_number(Visitor *v, const char *name, double *obj,
107                        Error **errp);
108 void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp);
109 
110 #endif
111