xref: /openbmc/qemu/include/qapi/visitor.h (revision da34e65c)
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 
20 /* This struct is layout-compatible with all other *List structs
21  * created by the qapi generator.  It is used as a typical
22  * singly-linked list. */
23 typedef struct GenericList {
24     struct GenericList *next;
25     char padding[];
26 } GenericList;
27 
28 /* This struct is layout-compatible with all Alternate types
29  * created by the qapi generator. */
30 typedef struct GenericAlternate {
31     QType type;
32     char padding[];
33 } GenericAlternate;
34 
35 void visit_start_struct(Visitor *v, const char *name, void **obj,
36                         size_t size, Error **errp);
37 void visit_end_struct(Visitor *v, Error **errp);
38 
39 void visit_start_list(Visitor *v, const char *name, Error **errp);
40 GenericList *visit_next_list(Visitor *v, GenericList **list, size_t size);
41 void visit_end_list(Visitor *v);
42 
43 /*
44  * Start the visit of an alternate @obj with the given @size.
45  *
46  * @name specifies the relationship to the containing struct (ignored
47  * for a top level visit, the name of the key if this alternate is
48  * part of an object, or NULL if this alternate is part of a list).
49  *
50  * @obj must not be NULL. Input visitors will allocate @obj and
51  * determine the qtype of the next thing to be visited, stored in
52  * (*@obj)->type.  Other visitors will leave @obj unchanged.
53  *
54  * If @promote_int, treat integers as QTYPE_FLOAT.
55  *
56  * If successful, this must be paired with visit_end_alternate(), even
57  * if visiting the contents of the alternate fails.
58  */
59 void visit_start_alternate(Visitor *v, const char *name,
60                            GenericAlternate **obj, size_t size,
61                            bool promote_int, Error **errp);
62 
63 /*
64  * Finish visiting an alternate type.
65  *
66  * Must be called after a successful visit_start_alternate(), even if
67  * an error occurred in the meantime.
68  *
69  * TODO: Should all the visit_end_* interfaces take obj parameter, so
70  * that dealloc visitor need not track what was passed in visit_start?
71  */
72 void visit_end_alternate(Visitor *v);
73 
74 /**
75  * Check if an optional member @name of an object needs visiting.
76  * For input visitors, set *@present according to whether the
77  * corresponding visit_type_*() needs calling; for other visitors,
78  * leave *@present unchanged.  Return *@present for convenience.
79  */
80 bool visit_optional(Visitor *v, const char *name, bool *present);
81 
82 void visit_type_enum(Visitor *v, const char *name, int *obj,
83                      const char *const strings[], Error **errp);
84 void visit_type_int(Visitor *v, const char *name, int64_t *obj, Error **errp);
85 void visit_type_uint8(Visitor *v, const char *name, uint8_t *obj,
86                       Error **errp);
87 void visit_type_uint16(Visitor *v, const char *name, uint16_t *obj,
88                        Error **errp);
89 void visit_type_uint32(Visitor *v, const char *name, uint32_t *obj,
90                        Error **errp);
91 void visit_type_uint64(Visitor *v, const char *name, uint64_t *obj,
92                        Error **errp);
93 void visit_type_int8(Visitor *v, const char *name, int8_t *obj, Error **errp);
94 void visit_type_int16(Visitor *v, const char *name, int16_t *obj,
95                       Error **errp);
96 void visit_type_int32(Visitor *v, const char *name, int32_t *obj,
97                       Error **errp);
98 void visit_type_int64(Visitor *v, const char *name, int64_t *obj,
99                       Error **errp);
100 void visit_type_size(Visitor *v, const char *name, uint64_t *obj,
101                      Error **errp);
102 void visit_type_bool(Visitor *v, const char *name, bool *obj, Error **errp);
103 void visit_type_str(Visitor *v, const char *name, char **obj, Error **errp);
104 void visit_type_number(Visitor *v, const char *name, double *obj,
105                        Error **errp);
106 void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp);
107 
108 #endif
109