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