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>

2 files changed, 4 insertions, 10 deletions

diff --git a/migration/migration.c b/migration/migration.c
index ccf969a6..3f4191a 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -406,12 +406,9 @@ int migration_incoming_enable_colo(void)
 void migrate_add_address(SocketAddress *address)
 {
     MigrationIncomingState *mis = migration_incoming_get_current();
-    SocketAddressList *addrs;
 
-    addrs = g_new0(SocketAddressList, 1);
-    addrs->next = mis->socket_address_list;
-    mis->socket_address_list = addrs;
-    addrs->value = QAPI_CLONE(SocketAddress, address);
+    QAPI_LIST_PREPEND(mis->socket_address_list,
+                      QAPI_CLONE(SocketAddress, address));
 }
 
 static void qemu_start_incoming_migration(const char *uri, Error **errp)
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index d99842e..ab482ad 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -145,14 +145,11 @@ static struct PostcopyBlocktimeContext *blocktime_context_new(void)
 static uint32List *get_vcpu_blocktime_list(PostcopyBlocktimeContext *ctx)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
-    uint32List *list = NULL, *entry = NULL;
+    uint32List *list = NULL;
     int i;
 
     for (i = ms->smp.cpus - 1; i >= 0; i--) {
-        entry = g_new0(uint32List, 1);
-        entry->value = ctx->vcpu_blocktime[i];
-        entry->next = list;
-        list = entry;
+        QAPI_LIST_PREPEND(list, ctx->vcpu_blocktime[i]);
     }
 
     return list;