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[Qemu-devel] [PATCH v9 34/37] qapi: Simplify semantics of visit_next_lis
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From: |
Eric Blake |
|
Subject: |
[Qemu-devel] [PATCH v9 34/37] qapi: Simplify semantics of visit_next_list() |
|
Date: |
Tue, 19 Jan 2016 09:10:42 -0700 |
We have two uses of list visits in the entire code base: one in
spapr_drc (which completely avoids visit_next_list(), feeding in
integers from a different source than uint8List), and one in
qapi-visit.py (that is, all other list visitors are generated
in qapi-visit.c, and share the same paradigm based on a qapi
FooList type). What's more, the semantics of the list visit are
somewhat baroque, with the following pseudocode when FooList is
used:
start()
prev = head
while (cur = next(prev)) {
visit(cur)
prev = &cur
}
Note that these semantics (advance before visit) requires that
the first call to next() return the list head, while all other
calls return the next element of the list; that is, every visitor
implementation is required to track extra state to decide whether
to return the input as-is, or to advance. It also requires an
argument of 'GenericList **' to next(), solely because the first
iteration might need to modify the caller's GenericList head, so
that all other calls have to do a layer of dereferencing.
We can greatly simplify things by hoisting the special case
into the start() routine, and flipping the order in the loop
to visit before advance:
start(head)
element = *head
while (element) {
visit(element)
element = next(element)
}
With the simpler semantics, visitors have less state to track,
the argument to next() is reduced to 'GenericList *', and it
also becomes obvious whether an input visitor is allocating a
FooList during visit_start_list() (rather than the old way of
not knowing if an allocation happened until the first
visit_next_list()).
The signature of visit_start_list() is chosen to match
visit_start_struct(), with the new parameter after 'name'.
The spapr_drc case requires that visit_start_list() has to pay
attention to whether visit_next_list() will even be used to
visit a FooList qapi struct; this is done by passing NULL for
list, similarly to how NULL is passed to visit_start_struct()
when a qapi type is not used in those visits. It was easy to
provide these semantics for qmp-output and dealloc visitors,
and a bit harder for qmp-input (it required hoisting the
advance of the current qlist entry out of qmp_input_next_list()
into qmp_input_get_object()). But it turned out that the
string and opts visitors munge enough state during
visit_next_list() to make those conversions simpler if they
require a GenericList visit for now; an assertion will remind
us to adjust things if we need the semantics in the future.
Signed-off-by: Eric Blake <address@hidden>
Reviewed-by: Marc-André Lureau <address@hidden>
---
v9: no change
v8: consistent parameter order, fix qmp_input_get_next_type() to not
skip list entries
v7: new patch
---
hw/ppc/spapr_drc.c | 2 +-
include/qapi/visitor-impl.h | 5 ++--
include/qapi/visitor.h | 45 +++++++++++++++++--------------
qapi/opts-visitor.c | 32 +++++++++-------------
qapi/qapi-dealloc-visitor.c | 29 +++++---------------
qapi/qapi-visit-core.c | 7 ++---
qapi/qmp-input-visitor.c | 64 +++++++++++++++++++++-----------------------
qapi/qmp-output-visitor.c | 21 +++------------
qapi/string-input-visitor.c | 34 +++++++++++------------
qapi/string-output-visitor.c | 36 ++++++++-----------------
scripts/qapi-visit.py | 21 ++++++++-------
11 files changed, 126 insertions(+), 170 deletions(-)
diff --git a/hw/ppc/spapr_drc.c b/hw/ppc/spapr_drc.c
index 3b27caa..41f2da0 100644
--- a/hw/ppc/spapr_drc.c
+++ b/hw/ppc/spapr_drc.c
@@ -299,7 +299,7 @@ static void prop_get_fdt(Object *obj, Visitor *v, const
char *name,
int i;
prop = fdt_get_property_by_offset(fdt, fdt_offset, &prop_len);
name = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
- visit_start_list(v, name, &err);
+ visit_start_list(v, name, NULL, &err);
if (err) {
error_propagate(errp, err);
return;
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 248b1e5..acbe7d6 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -40,9 +40,10 @@ struct Visitor
void (*end_implicit_struct)(Visitor *v);
/* Must be set */
- void (*start_list)(Visitor *v, const char *name, Error **errp);
+ void (*start_list)(Visitor *v, const char *name, GenericList **list,
+ Error **errp);
/* Must be set */
- GenericList *(*next_list)(Visitor *v, GenericList **list, Error **errp);
+ GenericList *(*next_list)(Visitor *v, GenericList *element, Error **errp);
/* Must be set */
void (*end_list)(Visitor *v);
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index e5dcde4..4638863 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -1,6 +1,7 @@
/*
* Core Definitions for QAPI Visitor Classes
*
+ * Copyright (C) 2015 Red Hat, Inc.
* Copyright IBM, Corp. 2011
*
* Authors:
@@ -111,32 +112,36 @@ void visit_end_implicit_struct(Visitor *v);
/**
* Prepare to visit a list tied to an object key @name.
* @name will be NULL if this is visited as part of another list.
- * After calling this, the elements must be collected until
- * visit_next_list() returns NULL, then visit_end_list() must be
- * used to complete the visit.
- */
-void visit_start_list(Visitor *v, const char *name, Error **errp);
-/**
- * Iterate over a GenericList during a list visit.
- * @list must not be NULL; on the first call, @list contains the
- * address of the list head, and on subsequent calls address@hidden must be
- * the previously returned value. Must be called in a loop until a
- * NULL return or error occurs; for each non-NULL return, the caller
- * must then call the appropriate visit_type_*() for the element type
- * of the list, with that function's name parameter set to NULL.
+ * Input visitors malloc a qapi List struct into address@hidden, or set it to
+ * NULL if there are no elements in the list; and output visitors
+ * expect address@hidden to point to the start of the list, if any. On
+ * return, if address@hidden is non-NULL, the caller should enter a loop
+ * visiting the current element, then using visit_next_list() to
+ * advance to the next element, until that returns NULL; then
+ * visit_end_list() must be used to complete the visit.
*
- * Note that for some visitors (qapi-dealloc and qmp-output), when a
- * qapi GenericList linked list is not being used (comparable to when
- * a NULL obj is used for visit_start_struct()), it is acceptable to
- * bypass the use of visit_next_list() and just directly call the
- * appropriate visit_type_*() for each element in between the
- * visit_start_list() and visit_end_list() calls.
+ * If supported by a visitor, @list can be NULL to indicate that there
+ * is no qapi List struct, and that the upcoming visit calls are
+ * parsing input to or creating output from some other representation;
+ * in this case, visit_next_list() will not be needed, but
+ * visit_end_list() is still mandatory.
*
* FIXME: For input visitors, address@hidden can be assigned here even if
* later visits will fail; this can lead to memory leaks if clients
* aren't careful.
*/
-GenericList *visit_next_list(Visitor *v, GenericList **list, Error **errp);
+void visit_start_list(Visitor *v, const char *name, GenericList **list,
+ Error **errp);
+/**
+ * Iterate over a GenericList during a list visit.
+ * Before calling this function, the caller should use the appropriate
+ * visit_type_FOO() for the current list element at @element->value, and
+ * check for errors. @element must not be NULL; on the first iteration,
+ * it should be the value in *list after visit_start_list(); on other
+ * calls it should be the previous return value. This function
+ * returns NULL once there are no further list elements.
+ */
+GenericList *visit_next_list(Visitor *v, GenericList *element, Error **errp);
/**
* Complete the list started earlier.
* Must be called after any successful use of visit_start_list(),
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index b469573..c5a7396 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -21,9 +21,8 @@
enum ListMode
{
LM_NONE, /* not traversing a list of repeated options */
- LM_STARTED, /* opts_start_list() succeeded */
- LM_IN_PROGRESS, /* opts_next_list() has been called.
+ LM_IN_PROGRESS, /* opts_next_list() ready to be called.
*
* Generating the next list link will consume the most
* recently parsed QemuOpt instance of the repeated
@@ -212,35 +211,32 @@ lookup_distinct(const OptsVisitor *ov, const char *name,
Error **errp)
static void
-opts_start_list(Visitor *v, const char *name, Error **errp)
+opts_start_list(Visitor *v, const char *name, GenericList **list, Error **errp)
{
OptsVisitor *ov = to_ov(v);
/* we can't traverse a list in a list */
assert(ov->list_mode == LM_NONE);
+ /* we don't support visits without GenericList, yet */
+ assert(list);
ov->repeated_opts = lookup_distinct(ov, name, errp);
- if (ov->repeated_opts != NULL) {
- ov->list_mode = LM_STARTED;
+ if (ov->repeated_opts) {
+ ov->list_mode = LM_IN_PROGRESS;
+ *list = g_new0(GenericList, 1);
+ } else {
+ *list = NULL;
}
}
static GenericList *
-opts_next_list(Visitor *v, GenericList **list, Error **errp)
+opts_next_list(Visitor *v, GenericList *list, Error **errp)
{
OptsVisitor *ov = to_ov(v);
- GenericList **link;
switch (ov->list_mode) {
- case LM_STARTED:
- ov->list_mode = LM_IN_PROGRESS;
- link = list;
- break;
-
case LM_SIGNED_INTERVAL:
case LM_UNSIGNED_INTERVAL:
- link = &(*list)->next;
-
if (ov->list_mode == LM_SIGNED_INTERVAL) {
if (ov->range_next.s < ov->range_limit.s) {
++ov->range_next.s;
@@ -261,7 +257,6 @@ opts_next_list(Visitor *v, GenericList **list, Error **errp)
g_hash_table_remove(ov->unprocessed_opts, opt->name);
return NULL;
}
- link = &(*list)->next;
break;
}
@@ -269,8 +264,8 @@ opts_next_list(Visitor *v, GenericList **list, Error **errp)
abort();
}
- *link = g_malloc0(sizeof **link);
- return *link;
+ list->next = g_new0(GenericList, 1);
+ return list->next;
}
@@ -279,8 +274,7 @@ opts_end_list(Visitor *v)
{
OptsVisitor *ov = to_ov(v);
- assert(ov->list_mode == LM_STARTED ||
- ov->list_mode == LM_IN_PROGRESS ||
+ assert(ov->list_mode == LM_IN_PROGRESS ||
ov->list_mode == LM_SIGNED_INTERVAL ||
ov->list_mode == LM_UNSIGNED_INTERVAL);
ov->repeated_opts = NULL;
diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c
index a89e6d1..839049e 100644
--- a/qapi/qapi-dealloc-visitor.c
+++ b/qapi/qapi-dealloc-visitor.c
@@ -20,7 +20,6 @@
typedef struct StackEntry
{
void *value;
- bool is_list_head;
QTAILQ_ENTRY(StackEntry) node;
} StackEntry;
@@ -41,10 +40,6 @@ static void qapi_dealloc_push(QapiDeallocVisitor *qov, void
*value)
e->value = value;
- /* see if we're just pushing a list head tracker */
- if (value == NULL) {
- e->is_list_head = true;
- }
QTAILQ_INSERT_HEAD(&qov->stack, e, node);
}
@@ -92,31 +87,19 @@ static void qapi_dealloc_end_implicit_struct(Visitor *v)
}
}
-static void qapi_dealloc_start_list(Visitor *v, const char *name, Error **errp)
+static void qapi_dealloc_start_list(Visitor *v, const char *name,
+ GenericList **list, Error **errp)
{
QapiDeallocVisitor *qov = to_qov(v);
qapi_dealloc_push(qov, NULL);
}
-static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList **listp,
+static GenericList *qapi_dealloc_next_list(Visitor *v, GenericList *list,
Error **errp)
{
- GenericList *list = *listp;
- QapiDeallocVisitor *qov = to_qov(v);
- StackEntry *e = QTAILQ_FIRST(&qov->stack);
-
- if (e && e->is_list_head) {
- e->is_list_head = false;
- return list;
- }
-
- if (list) {
- list = list->next;
- g_free(*listp);
- return list;
- }
-
- return NULL;
+ GenericList *next = list->next;
+ g_free(list);
+ return next;
}
static void qapi_dealloc_end_list(Visitor *v)
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 9506a02..f391a70 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -67,12 +67,13 @@ void visit_end_implicit_struct(Visitor *v)
}
}
-void visit_start_list(Visitor *v, const char *name, Error **errp)
+void visit_start_list(Visitor *v, const char *name, GenericList **list,
+ Error **errp)
{
- v->start_list(v, name, errp);
+ v->start_list(v, name, list, errp);
}
-GenericList *visit_next_list(Visitor *v, GenericList **list, Error **errp)
+GenericList *visit_next_list(Visitor *v, GenericList *list, Error **errp)
{
assert(list);
return v->next_list(v, list, errp);
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index f256d9e..82f9333 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -44,16 +44,20 @@ static QObject *qmp_input_get_object(QmpInputVisitor *qiv,
const char *name,
bool consume)
{
- QObject *qobj = qiv->stack[qiv->nb_stack - 1].obj;
+ StackObject *so = &qiv->stack[qiv->nb_stack - 1];
+ QObject *qobj = so->obj;
if (qobj) {
if (name && qobject_type(qobj) == QTYPE_QDICT) {
- if (qiv->stack[qiv->nb_stack - 1].h && consume) {
- g_hash_table_remove(qiv->stack[qiv->nb_stack - 1].h, name);
+ if (so->h && consume) {
+ g_hash_table_remove(so->h, name);
+ }
+ qobj = qdict_get(qobject_to_qdict(qobj), name);
+ } else if (so->entry) {
+ qobj = qlist_entry_obj(so->entry);
+ if (consume) {
+ so->entry = qlist_next(so->entry);
}
- return qdict_get(qobject_to_qdict(qobj), name);
- } else if (qiv->stack[qiv->nb_stack - 1].entry) {
- return qlist_entry_obj(qiv->stack[qiv->nb_stack - 1].entry);
}
}
@@ -66,7 +70,8 @@ static void qdict_add_key(const char *key, QObject *obj, void
*opaque)
g_hash_table_insert(h, (gpointer) key, NULL);
}
-static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj, Error **errp)
+static void qmp_input_push(QmpInputVisitor *qiv, QObject *obj,
+ const QListEntry *entry, Error **errp)
{
GHashTable *h;
@@ -76,7 +81,7 @@ static void qmp_input_push(QmpInputVisitor *qiv, QObject
*obj, Error **errp)
}
qiv->stack[qiv->nb_stack].obj = obj;
- qiv->stack[qiv->nb_stack].entry = NULL;
+ qiv->stack[qiv->nb_stack].entry = entry;
qiv->stack[qiv->nb_stack].h = NULL;
if (qiv->strict && qobject_type(obj) == QTYPE_QDICT) {
@@ -138,7 +143,7 @@ static void qmp_input_start_struct(Visitor *v, const char
*name, void **obj,
return;
}
- qmp_input_push(qiv, qobj, &err);
+ qmp_input_push(qiv, qobj, NULL, &err);
if (err) {
error_propagate(errp, err);
return;
@@ -158,10 +163,12 @@ static void qmp_input_start_implicit_struct(Visitor *v,
void **obj,
}
}
-static void qmp_input_start_list(Visitor *v, const char *name, Error **errp)
+static void qmp_input_start_list(Visitor *v, const char *name,
+ GenericList **list, Error **errp)
{
QmpInputVisitor *qiv = to_qiv(v);
QObject *qobj = qmp_input_get_object(qiv, name, true);
+ const QListEntry *entry;
if (!qobj || qobject_type(qobj) != QTYPE_QLIST) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
@@ -169,37 +176,28 @@ static void qmp_input_start_list(Visitor *v, const char
*name, Error **errp)
return;
}
- qmp_input_push(qiv, qobj, errp);
+ entry = qlist_first(qobject_to_qlist(qobj));
+ qmp_input_push(qiv, qobj, entry, errp);
+ if (list) {
+ if (entry) {
+ *list = g_new0(GenericList, 1);
+ } else {
+ *list = NULL;
+ }
+ }
}
-static GenericList *qmp_input_next_list(Visitor *v, GenericList **list,
+static GenericList *qmp_input_next_list(Visitor *v, GenericList *list,
Error **errp)
{
QmpInputVisitor *qiv = to_qiv(v);
- GenericList *entry;
StackObject *so = &qiv->stack[qiv->nb_stack - 1];
- bool first;
- if (so->entry == NULL) {
- so->entry = qlist_first(qobject_to_qlist(so->obj));
- first = true;
- } else {
- so->entry = qlist_next(so->entry);
- first = false;
- }
-
- if (so->entry == NULL) {
+ if (!so->entry) {
return NULL;
}
-
- entry = g_malloc0(sizeof(*entry));
- if (first) {
- *list = entry;
- } else {
- (*list)->next = entry;
- }
-
- return entry;
+ list->next = g_new0(GenericList, 1);
+ return list->next;
}
@@ -375,7 +373,7 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
v->visitor.optional = qmp_input_optional;
v->visitor.get_next_type = qmp_input_get_next_type;
- qmp_input_push(v, obj, NULL);
+ qmp_input_push(v, obj, NULL, NULL);
qobject_incref(obj);
return v;
diff --git a/qapi/qmp-output-visitor.c b/qapi/qmp-output-visitor.c
index 5376948..913f378 100644
--- a/qapi/qmp-output-visitor.c
+++ b/qapi/qmp-output-visitor.c
@@ -21,7 +21,6 @@
typedef struct QStackEntry
{
QObject *value;
- bool is_list_head;
QTAILQ_ENTRY(QStackEntry) node;
} QStackEntry;
@@ -51,9 +50,6 @@ static void qmp_output_push_obj(QmpOutputVisitor *qov,
QObject *value)
assert(qov->root);
assert(value);
e->value = value;
- if (qobject_type(e->value) == QTYPE_QLIST) {
- e->is_list_head = true;
- }
QTAILQ_INSERT_HEAD(&qov->stack, e, node);
}
@@ -122,7 +118,8 @@ static void qmp_output_end_struct(Visitor *v)
qmp_output_pop(qov, QTYPE_QDICT);
}
-static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
+static void qmp_output_start_list(Visitor *v, const char *name,
+ GenericList **listp, Error **errp)
{
QmpOutputVisitor *qov = to_qov(v);
QList *list = qlist_new();
@@ -131,20 +128,10 @@ static void qmp_output_start_list(Visitor *v, const char
*name, Error **errp)
qmp_output_push(qov, list);
}
-static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
+static GenericList *qmp_output_next_list(Visitor *v, GenericList *list,
Error **errp)
{
- GenericList *list = *listp;
- QmpOutputVisitor *qov = to_qov(v);
- QStackEntry *e = QTAILQ_FIRST(&qov->stack);
-
- assert(e);
- if (e->is_list_head) {
- e->is_list_head = false;
- return list;
- }
-
- return list ? list->next : NULL;
+ return list->next;
}
static void qmp_output_end_list(Visitor *v)
diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
index 610c233..582a62a 100644
--- a/qapi/string-input-visitor.c
+++ b/qapi/string-input-visitor.c
@@ -23,8 +23,6 @@ struct StringInputVisitor
{
Visitor visitor;
- bool head;
-
GList *ranges;
GList *cur_range;
int64_t cur;
@@ -123,11 +121,19 @@ error:
}
static void
-start_list(Visitor *v, const char *name, Error **errp)
+start_list(Visitor *v, const char *name, GenericList **list, Error **errp)
{
StringInputVisitor *siv = to_siv(v);
+ Error *err = NULL;
- parse_str(siv, errp);
+ /* We don't support visits without a GenericList, yet */
+ assert(list);
+
+ parse_str(siv, &err);
+ if (err) {
+ error_propagate(errp, err);
+ return;
+ }
siv->cur_range = g_list_first(siv->ranges);
if (siv->cur_range) {
@@ -135,14 +141,16 @@ start_list(Visitor *v, const char *name, Error **errp)
if (r) {
siv->cur = r->begin;
}
+ *list = g_new0(GenericList, 1);
+ } else {
+ *list = NULL;
}
}
static GenericList *
-next_list(Visitor *v, GenericList **list, Error **errp)
+next_list(Visitor *v, GenericList *list, Error **errp)
{
StringInputVisitor *siv = to_siv(v);
- GenericList **link;
Range *r;
if (!siv->ranges || !siv->cur_range) {
@@ -166,22 +174,13 @@ next_list(Visitor *v, GenericList **list, Error **errp)
siv->cur = r->begin;
}
- if (siv->head) {
- link = list;
- siv->head = false;
- } else {
- link = &(*list)->next;
- }
-
- *link = g_malloc0(sizeof **link);
- return *link;
+ list->next = g_new0(GenericList, 1);
+ return list->next;
}
static void
end_list(Visitor *v)
{
- StringInputVisitor *siv = to_siv(v);
- siv->head = true;
}
static void parse_type_int64(Visitor *v, const char *name, int64_t *obj,
@@ -361,6 +360,5 @@ StringInputVisitor *string_input_visitor_new(const char
*str)
v->visitor.optional = parse_optional;
v->string = str;
- v->head = true;
return v;
}
diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
index fd917a4..7209d80 100644
--- a/qapi/string-output-visitor.c
+++ b/qapi/string-output-visitor.c
@@ -57,7 +57,6 @@ struct StringOutputVisitor
Visitor visitor;
bool human;
GString *string;
- bool head;
ListMode list_mode;
union {
int64_t s;
@@ -265,40 +264,29 @@ static void print_type_number(Visitor *v, const char
*name, double *obj,
}
static void
-start_list(Visitor *v, const char *name, Error **errp)
+start_list(Visitor *v, const char *name, GenericList **list, Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
/* we can't traverse a list in a list */
assert(sov->list_mode == LM_NONE);
- sov->list_mode = LM_STARTED;
- sov->head = true;
+ /* We don't support visits without a GenericList, yet */
+ assert(list);
+ /* List handling is only needed if there are at least two elements */
+ if (*list && (*list)->next) {
+ sov->list_mode = LM_STARTED;
+ }
}
static GenericList *
-next_list(Visitor *v, GenericList **list, Error **errp)
+next_list(Visitor *v, GenericList *list, Error **errp)
{
StringOutputVisitor *sov = to_sov(v);
- GenericList *ret = NULL;
- if (*list) {
- if (sov->head) {
- ret = *list;
- } else {
- ret = (*list)->next;
- }
+ GenericList *ret = list->next;
- if (sov->head) {
- if (ret && ret->next == NULL) {
- sov->list_mode = LM_NONE;
- }
- sov->head = false;
- } else {
- if (ret && ret->next == NULL) {
- sov->list_mode = LM_END;
- }
- }
+ if (ret && !ret->next) {
+ sov->list_mode = LM_END;
}
-
return ret;
}
@@ -312,8 +300,6 @@ end_list(Visitor *v)
sov->list_mode == LM_NONE ||
sov->list_mode == LM_IN_PROGRESS);
sov->list_mode = LM_NONE;
- sov->head = true;
-
}
char *string_output_get_string(StringOutputVisitor *sov)
diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index 8039b97..6016734 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -125,20 +125,23 @@ def gen_visit_list(name, element_type):
void visit_type_%(c_name)s(Visitor *v, const char *name, %(c_name)s **obj,
Error **errp)
{
Error *err = NULL;
- GenericList *i, **prev;
+ %(c_name)s *elt;
- visit_start_list(v, name, &err);
+ visit_start_list(v, name, (GenericList **)obj, &err);
if (err) {
goto out;
}
-
- for (prev = (GenericList **)obj;
- !err && (i = visit_next_list(v, prev, &err)) != NULL;
- prev = &i) {
- %(c_name)s *native_i = (%(c_name)s *)i;
- visit_type_%(c_elt_type)s(v, NULL, &native_i->value, &err);
+ elt = *obj;
+ while (elt) {
+ visit_type_%(c_elt_type)s(v, NULL, &elt->value, &err);
+ if (err) {
+ break;
+ }
+ elt = (%(c_name)s *)visit_next_list(v, (GenericList *)elt, &err);
+ if (err) {
+ break;
+ }
}
-
visit_end_list(v);
out:
error_propagate(errp, err);
--
2.5.0
[Qemu-devel] [PATCH v9 34/37] qapi: Simplify semantics of visit_next_list(),
Eric Blake <=
[Qemu-devel] [PATCH v9 15/37] qom: Swap 'name' next to visitor in ObjectPropertyAccessor, Eric Blake, 2016/01/19
[Qemu-devel] [PATCH v9 14/37] qapi: Swap visit_* arguments for consistent 'name' placement, Eric Blake, 2016/01/19
Re: [Qemu-devel] [PATCH v9 00/37] qapi visitor cleanups (post-introspection cleanups subset E), Markus Armbruster, 2016/01/28