qapi: Use QAPI_LIST_PREPEND() where possible

Anywhere we create a list of just one item or by prepending items
(typically because order doesn't matter), we can use
QAPI_LIST_PREPEND().  But places where we must keep the list in order
by appending remain open-coded until later patches.

Note that as a side effect, this also performs a cleanup of two minor
issues in qga/commands-posix.c: the old code was performing
 new = g_malloc0(sizeof(*ret));
which 1) is confusing because you have to verify whether 'new' and
'ret' are variables with the same type, and 2) would conflict with C++
compilation (not an actual problem for this file, but makes
copy-and-paste harder).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201113011340.463563-5-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
[Straightforward conflicts due to commit a8aa94b5f8 "qga: update
schema for guest-get-disks 'dependents' field" and commit a10b453a52
"target/mips: Move mips_cpu_add_definition() from helper.c to cpu.c"
resolved.  Commit message tweaked.]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 8 insertions, 12 deletions

diff --git a/chardev/char.c b/chardev/char.c
index a9b8c5a..288efeb 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -776,15 +776,13 @@ static int qmp_query_chardev_foreach(Object *obj, void *data)
 {
     Chardev *chr = CHARDEV(obj);
     ChardevInfoList **list = data;
-    ChardevInfoList *info = g_malloc0(sizeof(*info));
+    ChardevInfo *value = g_malloc0(sizeof(*value));
 
-    info->value = g_malloc0(sizeof(*info->value));
-    info->value->label = g_strdup(chr->label);
-    info->value->filename = g_strdup(chr->filename);
-    info->value->frontend_open = chr->be && chr->be->fe_open;
+    value->label = g_strdup(chr->label);
+    value->filename = g_strdup(chr->filename);
+    value->frontend_open = chr->be && chr->be->fe_open;
 
-    info->next = *list;
-    *list = info;
+    QAPI_LIST_PREPEND(*list, value);
 
     return 0;
 }
@@ -803,12 +801,10 @@ static void
 qmp_prepend_backend(const char *name, void *opaque)
 {
     ChardevBackendInfoList **list = opaque;
-    ChardevBackendInfoList *info = g_malloc0(sizeof(*info));
+    ChardevBackendInfo *value = g_new0(ChardevBackendInfo, 1);
 
-    info->value = g_malloc0(sizeof(*info->value));
-    info->value->name = g_strdup(name);
-    info->next = *list;
-    *list = info;
+    value->name = g_strdup(name);
+    QAPI_LIST_PREPEND(*list, value);
 }
 
 ChardevBackendInfoList *qmp_query_chardev_backends(Error **errp)