include/qapi/visitor.h

   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