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 #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