Our existing input visitors were not very consistent on errors
in a function taking 'TYPE **obj'. While all of them set '*obj'
to allocated storage on success, it was not obvious whether
'*obj' was guaranteed safe on failure, or whether it was left
uninitialized. But a future patch wants to guarantee that
visit_type_FOO() does not leak a partially-constructed obj back
to the caller; it is easier to implement this if we can reliably
state that '*obj' is assigned on exit, even on failures.
The opts-visitor start_struct() doesn't set an error, but it
also was doing a weird check for 0 size; all callers pass in
non-zero size if obj is non-NULL.
Signed-off-by: Eric Blake <ebl...@redhat.com>
---
v13: no change
v12: new patch
---
qapi/opts-visitor.c | 3 ++-
qapi/qmp-input-visitor.c | 4 ++++
qapi/string-input-visitor.c | 1 +
3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
index f9a2346..fd90608 100644
--- a/qapi/opts-visitor.c
+++ b/qapi/opts-visitor.c
@@ -132,7 +132,7 @@ opts_start_struct(Visitor *v, const char *name, void **obj,
const QemuOpt *opt;
if (obj) {
- *obj = g_malloc0(size > 0 ? size : 1);
+ *obj = g_malloc0(size);
}
if (ov->depth++ > 0) {
return;
@@ -313,6 +313,7 @@ opts_type_str(Visitor *v, const char *name, char **obj,
Error **errp)
opt = lookup_scalar(ov, name, errp);
if (!opt) {
+ *obj = NULL;
return;
}
*obj = g_strdup(opt->str ? opt->str : "");
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 03dcb65..550aed6 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -119,6 +119,9 @@ static void qmp_input_start_struct(Visitor *v, const char
*name, void **obj,
QObject *qobj = qmp_input_get_object(qiv, name, true);
Error *err = NULL;
+ if (obj) {
+ *obj = NULL;
+ }
if (!qobj || qobject_type(qobj) != QTYPE_QDICT) {
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"QDict");
@@ -266,6 +269,7 @@ static void qmp_input_type_str(Visitor *v, const char
*name, char **obj,
QString *qstr = qobject_to_qstring(qmp_input_get_object(qiv, name, true));
if (!qstr) {
+ *obj = NULL;
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"string");
return;
diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
index d591e67..4087bf9 100644
--- a/qapi/string-input-visitor.c
+++ b/qapi/string-input-visitor.c
@@ -292,6 +292,7 @@ static void parse_type_str(Visitor *v, const char *name,
char **obj,
if (siv->string) {
*obj = g_strdup(siv->string);
} else {
+ *obj = NULL;
error_setg(errp, QERR_INVALID_PARAMETER_TYPE, name ? name : "null",
"string");
}
--
2.5.0
