This makes qobject-input-visitor remember the currently valid aliases in
each StackObject. It doesn't actually allow using the aliases yet.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
qapi/qobject-input-visitor.c | 147 +++++++++++++++++++++++++++++++++++
1 file changed, 147 insertions(+)
diff --git a/qapi/qobject-input-visitor.c b/qapi/qobject-input-visitor.c
index 04b790412e..d0061d33d6 100644
--- a/qapi/qobject-input-visitor.c
+++ b/qapi/qobject-input-visitor.c
@@ -30,6 +30,50 @@
#include "qemu/cutils.h"
#include "qemu/option.h"
+/*
+ * Describes an alias that is relevant for the current StackObject,
+ * either because it aliases a member of the currently visited object
+ * or because it aliases a member of a nested object.
+ *
+ * When processing a nested object, all InputVisitorAlias objects that
+ * are relevant for the nested object are propagated, i.e. copied with
+ * the name of the nested object removed from @source.
+ */
+typedef struct InputVisitorAlias {
+ /* StackObject in which the alias was defined */
+ struct StackObject *alias_so;
+
+ /*
+ * Alias name as defined for @alias_so.
+ * NULL means that this is a wildcard alias, i.e. all members of
+ * @src get an alias in @alias_so with the same name.
+ */
+ const char *name;
+
+ /*
+ * NULL-terminated array representing a path to the source member
+ * that the alias refers to.
+ *
+ * Must contain at least one non-NULL element if @alias is not NULL.
+ *
+ * If it contains no non-NULL element, @alias_so must be different
+ * from the StackObject which contains this InputVisitorAlias in
+ * its aliases list. In this case, all elements in the currently
+ * visited object have an alias with the same name in @alias_so.
+ */
+ const char **src;
+
+ /*
+ * The alias remains valid as long as the StackObject which
+ * contains this InputVisitorAlias in its aliases list has
+ * StackObject.alias_scope_nesting >= InputVisitorAlias.scope_nesting
+ * or until the whole StackObject is removed.
+ */
+ int scope_nesting;
+
+ QSLIST_ENTRY(InputVisitorAlias) next;
+} InputVisitorAlias;
+
typedef struct StackObject {
const char *name; /* Name of @obj in its parent, if any */
QObject *obj; /* QDict or QList being visited */
@@ -39,6 +83,9 @@ typedef struct StackObject {
const QListEntry *entry; /* If @obj is QList: unvisited tail */
unsigned index; /* If @obj is QList: list index of @entry */
+ QSLIST_HEAD(, InputVisitorAlias) aliases;
+ int alias_scope_nesting; /* Number of open alias scopes */
+
QSLIST_ENTRY(StackObject) node; /* parent */
} StackObject;
@@ -205,6 +252,45 @@ static const char
*qobject_input_get_keyval(QObjectInputVisitor *qiv,
return qstring_get_str(qstr);
}
+/*
+ * Propagate aliases from the parent StackObject @src to its direct
+ * child StackObject @dst, which is representing the child struct @name.
+ *
+ * Every alias whose source path begins with @dst->name and which still
+ * applies in @dst (i.e. it is either a wildcard alias or has at least
+ * one more source path element) is propagated to @dst with the first
+ * element (i.e. @dst->name) removed from the source path.
+ */
+static void propagate_aliases(StackObject *dst, StackObject *src)
+{
+ InputVisitorAlias *a;
+ InputVisitorAlias *propagated_alias;
+
+ QSLIST_FOREACH(a, &src->aliases, next) {
+ if (!a->src[0] || strcmp(a->src[0], dst->name)) {
+ continue;
+ }
+
+ /*
+ * If this is not a wildcard alias, but a->src[1] is NULL,
+ * then it referred to a->name in src and doesn't apply inside
+ * dst any more.
+ */
+ if (a->name && !a->src[1]) {
+ continue;
+ }
+
+ propagated_alias = g_new(InputVisitorAlias, 1);
+ *propagated_alias = (InputVisitorAlias) {
+ .name = a->name,
+ .alias_so = a->alias_so,
+ .src = &a->src[1],
+ };
+
+ QSLIST_INSERT_HEAD(&dst->aliases, propagated_alias, next);
+ }
+}
+
static const QListEntry *qobject_input_push(QObjectInputVisitor *qiv,
const char *name,
QObject *obj, void *qapi)
@@ -228,6 +314,9 @@ static const QListEntry
*qobject_input_push(QObjectInputVisitor *qiv,
g_hash_table_insert(h, (void *)qdict_entry_key(entry), NULL);
}
tos->h = h;
+ if (!QSLIST_EMPTY(&qiv->stack)) {
+ propagate_aliases(tos, QSLIST_FIRST(&qiv->stack));
+ }
} else {
assert(qlist);
tos->entry = qlist_first(qlist);
@@ -259,10 +348,17 @@ static bool qobject_input_check_struct(Visitor *v, Error
**errp)
static void qobject_input_stack_object_free(StackObject *tos)
{
+ InputVisitorAlias *a;
+
if (tos->h) {
g_hash_table_unref(tos->h);
}
+ while ((a = QSLIST_FIRST(&tos->aliases))) {
+ QSLIST_REMOVE_HEAD(&tos->aliases, next);
+ g_free(a);
+ }
+
g_free(tos);
}
@@ -276,6 +372,54 @@ static void qobject_input_pop(Visitor *v, void **obj)
qobject_input_stack_object_free(tos);
}
+static void qobject_input_start_alias_scope(Visitor *v)
+{
+ QObjectInputVisitor *qiv = to_qiv(v);
+ StackObject *tos = QSLIST_FIRST(&qiv->stack);
+
+ tos->alias_scope_nesting++;
+}
+
+static void qobject_input_end_alias_scope(Visitor *v)
+{
+ QObjectInputVisitor *qiv = to_qiv(v);
+ StackObject *tos = QSLIST_FIRST(&qiv->stack);
+ InputVisitorAlias *a, *next;
+
+ assert(tos->alias_scope_nesting > 0);
+ tos->alias_scope_nesting--;
+
+ QSLIST_FOREACH_SAFE(a, &tos->aliases, next, next) {
+ if (a->scope_nesting > tos->alias_scope_nesting) {
+ QSLIST_REMOVE(&tos->aliases, a, InputVisitorAlias, next);
+ g_free(a);
+ }
+ }
+}
+
+static void qobject_input_define_alias(Visitor *v, const char *name,
+ const char **source)
+{
+ QObjectInputVisitor *qiv = to_qiv(v);
+ StackObject *tos = QSLIST_FIRST(&qiv->stack);
+ InputVisitorAlias *alias = g_new(InputVisitorAlias, 1);
+
+ /*
+ * The source path can become empty during alias propagation for
+ * wildcard aliases, but not when defining an alias (it would map
+ * all names onto themselves, which doesn't make sense).
+ */
+ assert(source[0]);
+
+ *alias = (InputVisitorAlias) {
+ .name = name,
+ .alias_so = tos,
+ .src = source,
+ };
+
+ QSLIST_INSERT_HEAD(&tos->aliases, alias, next);
+}
+
static bool qobject_input_start_struct(Visitor *v, const char *name, void
**obj,
size_t size, Error **errp)
{
@@ -717,6 +861,9 @@ static QObjectInputVisitor
*qobject_input_visitor_base_new(QObject *obj)
v->visitor.start_alternate = qobject_input_start_alternate;
v->visitor.optional = qobject_input_optional;
v->visitor.deprecated_accept = qobject_input_deprecated_accept;
+ v->visitor.define_alias = qobject_input_define_alias;
+ v->visitor.start_alias_scope = qobject_input_start_alias_scope;
+ v->visitor.end_alias_scope = qobject_input_end_alias_scope;
v->visitor.free = qobject_input_free;
v->root = qobject_ref(obj);
--
2.31.1
