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, 10 insertions, 12 deletions

diff --git a/trace/qmp.c b/trace/qmp.c
index 38246e1aa6..85f81e47cc 100644
--- a/trace/qmp.c
+++ b/trace/qmp.c
@@ -92,39 +92,37 @@ TraceEventInfoList *qmp_trace_event_get_state(const char *name,
     /* Get states (all errors checked above) */
     trace_event_iter_init(&iter, name);
     while ((ev = trace_event_iter_next(&iter)) != NULL) {
-        TraceEventInfoList *elem;
+        TraceEventInfo *value;
         bool is_vcpu = trace_event_is_vcpu(ev);
         if (has_vcpu && !is_vcpu) {
             continue;
         }
 
-        elem = g_new(TraceEventInfoList, 1);
-        elem->value = g_new(TraceEventInfo, 1);
-        elem->value->vcpu = is_vcpu;
-        elem->value->name = g_strdup(trace_event_get_name(ev));
+        value = g_new(TraceEventInfo, 1);
+        value->vcpu = is_vcpu;
+        value->name = g_strdup(trace_event_get_name(ev));
 
         if (!trace_event_get_state_static(ev)) {
-            elem->value->state = TRACE_EVENT_STATE_UNAVAILABLE;
+            value->state = TRACE_EVENT_STATE_UNAVAILABLE;
         } else {
             if (has_vcpu) {
                 if (is_vcpu) {
                     if (trace_event_get_vcpu_state_dynamic(cpu, ev)) {
-                        elem->value->state = TRACE_EVENT_STATE_ENABLED;
+                        value->state = TRACE_EVENT_STATE_ENABLED;
                     } else {
-                        elem->value->state = TRACE_EVENT_STATE_DISABLED;
+                        value->state = TRACE_EVENT_STATE_DISABLED;
                     }
                 }
                 /* else: already skipped above */
             } else {
                 if (trace_event_get_state_dynamic(ev)) {
-                    elem->value->state = TRACE_EVENT_STATE_ENABLED;
+                    value->state = TRACE_EVENT_STATE_ENABLED;
                 } else {
-                    elem->value->state = TRACE_EVENT_STATE_DISABLED;
+                    value->state = TRACE_EVENT_STATE_DISABLED;
                 }
             }
         }
-        elem->next = events;
-        events = elem;
+        QAPI_LIST_PREPEND(events, value);
     }
 
     return events;