LXR qemu/qapi/qapi-clone-visitor.c

   1/*
   2 * Copy one QAPI object to another
   3 *
   4 * Copyright (C) 2016 Red Hat, Inc.
   5 *
   6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7 * See the COPYING file in the top-level directory.
   8 *
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "qapi/clone-visitor.h"
  13#include "qapi/visitor-impl.h"
  14#include "qapi/error.h"
  15
  16struct QapiCloneVisitor {
  17    Visitor visitor;
  18    size_t depth;
  19};
  20
  21static QapiCloneVisitor *to_qcv(Visitor *v)
  22{
  23    return container_of(v, QapiCloneVisitor, visitor);
  24}
  25
  26static void qapi_clone_start_struct(Visitor *v, const char *name, void **obj,
  27                                    size_t size, Error **errp)
  28{
  29    QapiCloneVisitor *qcv = to_qcv(v);
  30
  31    if (!obj) {
  32        assert(qcv->depth);
  33        /* Only possible when visiting an alternate's object
  34         * branch. Nothing further to do here, since the earlier
  35         * visit_start_alternate() already copied memory. */
  36        return;
  37    }
  38
  39    *obj = g_memdup(*obj, size);
  40    qcv->depth++;
  41}
  42
  43static void qapi_clone_end(Visitor *v, void **obj)
  44{
  45    QapiCloneVisitor *qcv = to_qcv(v);
  46
  47    assert(qcv->depth);
  48    if (obj) {
  49        qcv->depth--;
  50    }
  51}
  52
  53static void qapi_clone_start_list(Visitor *v, const char *name,
  54                                  GenericList **listp, size_t size,
  55                                  Error **errp)
  56{
  57    qapi_clone_start_struct(v, name, (void **)listp, size, errp);
  58}
  59
  60static GenericList *qapi_clone_next_list(Visitor *v, GenericList *tail,
  61                                         size_t size)
  62{
  63    QapiCloneVisitor *qcv = to_qcv(v);
  64
  65    assert(qcv->depth);
  66    /* Unshare the tail of the list cloned by g_memdup() */
  67    tail->next = g_memdup(tail->next, size);
  68    return tail->next;
  69}
  70
  71static void qapi_clone_start_alternate(Visitor *v, const char *name,
  72                                       GenericAlternate **obj, size_t size,
  73                                       bool promote_int, Error **errp)
  74{
  75    qapi_clone_start_struct(v, name, (void **)obj, size, errp);
  76}
  77
  78static void qapi_clone_type_int64(Visitor *v, const char *name, int64_t *obj,
  79                                   Error **errp)
  80{
  81    QapiCloneVisitor *qcv = to_qcv(v);
  82
  83    assert(qcv->depth);
  84    /* Value was already cloned by g_memdup() */
  85}
  86
  87static void qapi_clone_type_uint64(Visitor *v, const char *name,
  88                                    uint64_t *obj, Error **errp)
  89{
  90    QapiCloneVisitor *qcv = to_qcv(v);
  91
  92    assert(qcv->depth);
  93    /* Value was already cloned by g_memdup() */
  94}
  95
  96static void qapi_clone_type_bool(Visitor *v, const char *name, bool *obj,
  97                                  Error **errp)
  98{
  99    QapiCloneVisitor *qcv = to_qcv(v);
 100
 101    assert(qcv->depth);
 102    /* Value was already cloned by g_memdup() */
 103}
 104
 105static void qapi_clone_type_str(Visitor *v, const char *name, char **obj,
 106                                 Error **errp)
 107{
 108    QapiCloneVisitor *qcv = to_qcv(v);
 109
 110    assert(qcv->depth);
 111    /*
 112     * Pointer was already cloned by g_memdup; create fresh copy.
 113     * Note that as long as qobject-output-visitor accepts NULL instead of
 114     * "", then we must do likewise. However, we want to obey the
 115     * input visitor semantics of never producing NULL when the empty
 116     * string is intended.
 117     */
 118    *obj = g_strdup(*obj ?: "");
 119}
 120
 121static void qapi_clone_type_number(Visitor *v, const char *name, double *obj,
 122                                    Error **errp)
 123{
 124    QapiCloneVisitor *qcv = to_qcv(v);
 125
 126    assert(qcv->depth);
 127    /* Value was already cloned by g_memdup() */
 128}
 129
 130static void qapi_clone_type_null(Visitor *v, const char *name, Error **errp)
 131{
 132    QapiCloneVisitor *qcv = to_qcv(v);
 133
 134    assert(qcv->depth);
 135    /* Nothing to do */
 136}
 137
 138static void qapi_clone_free(Visitor *v)
 139{
 140    g_free(v);
 141}
 142
 143static Visitor *qapi_clone_visitor_new(void)
 144{
 145    QapiCloneVisitor *v;
 146
 147    v = g_malloc0(sizeof(*v));
 148
 149    v->visitor.type = VISITOR_CLONE;
 150    v->visitor.start_struct = qapi_clone_start_struct;
 151    v->visitor.end_struct = qapi_clone_end;
 152    v->visitor.start_list = qapi_clone_start_list;
 153    v->visitor.next_list = qapi_clone_next_list;
 154    v->visitor.end_list = qapi_clone_end;
 155    v->visitor.start_alternate = qapi_clone_start_alternate;
 156    v->visitor.end_alternate = qapi_clone_end;
 157    v->visitor.type_int64 = qapi_clone_type_int64;
 158    v->visitor.type_uint64 = qapi_clone_type_uint64;
 159    v->visitor.type_bool = qapi_clone_type_bool;
 160    v->visitor.type_str = qapi_clone_type_str;
 161    v->visitor.type_number = qapi_clone_type_number;
 162    v->visitor.type_null = qapi_clone_type_null;
 163    v->visitor.free = qapi_clone_free;
 164
 165    return &v->visitor;
 166}
 167
 168void *qapi_clone(const void *src, void (*visit_type)(Visitor *, const char *,
 169                                                     void **, Error **))
 170{
 171    Visitor *v;
 172    void *dst = (void *) src; /* Cast away const */
 173
 174    if (!src) {
 175        return NULL;
 176    }
 177
 178    v = qapi_clone_visitor_new();
 179    visit_type(v, NULL, &dst, &error_abort);
 180    visit_free(v);
 181    return dst;
 182}
 183