chardev: Drop useless ChardevDummy type

Commit d0d7708b made ChardevDummy be an empty wrapper type around
ChardevCommon.  But there is no technical reason for this indirection,
so simplify the code by directly using the base type.

Also change the fallback assignment to assign u.null rather than
u.data, since a future patch will remove the data member of the C
struct generated for QAPI unions.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1457106160-23614-1-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

4 files changed, 12 insertions, 15 deletions

diff --git a/backends/baum.c b/backends/baum.c
index 374562a..c11320e 100644
--- a/backends/baum.c
+++ b/backends/baum.c
@@ -567,7 +567,7 @@ static CharDriverState *chr_baum_init(const char *id,
                                       ChardevReturn *ret,
                                       Error **errp)
 {
-    ChardevCommon *common = qapi_ChardevDummy_base(backend->u.braille);
+    ChardevCommon *common = backend->u.braille;
     BaumDriverState *baum;
     CharDriverState *chr;
     brlapi_handle_t *handle;
diff --git a/backends/msmouse.c b/backends/msmouse.c
index 9a82efd..5e1833c 100644
--- a/backends/msmouse.c
+++ b/backends/msmouse.c
@@ -68,7 +68,7 @@ static CharDriverState *qemu_chr_open_msmouse(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevCommon *common = qapi_ChardevDummy_base(backend->u.msmouse);
+    ChardevCommon *common = backend->u.msmouse;
     CharDriverState *chr;
 
     chr = qemu_chr_alloc(common, errp);
diff --git a/qapi-schema.json b/qapi-schema.json
index 42fd61b..362c9d8 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -3323,23 +3323,20 @@
 #
 # Since: 1.4 (testdev since 2.2)
 ##
-{ 'struct': 'ChardevDummy', 'data': { },
-  'base': 'ChardevCommon' }
-
 { 'union': 'ChardevBackend', 'data': { 'file'   : 'ChardevFile',
                                        'serial' : 'ChardevHostdev',
                                        'parallel': 'ChardevHostdev',
                                        'pipe'   : 'ChardevHostdev',
                                        'socket' : 'ChardevSocket',
                                        'udp'    : 'ChardevUdp',
-                                       'pty'    : 'ChardevDummy',
-                                       'null'   : 'ChardevDummy',
+                                       'pty'    : 'ChardevCommon',
+                                       'null'   : 'ChardevCommon',
                                        'mux'    : 'ChardevMux',
-                                       'msmouse': 'ChardevDummy',
-                                       'braille': 'ChardevDummy',
-                                       'testdev': 'ChardevDummy',
+                                       'msmouse': 'ChardevCommon',
+                                       'braille': 'ChardevCommon',
+                                       'testdev': 'ChardevCommon',
                                        'stdio'  : 'ChardevStdio',
-                                       'console': 'ChardevDummy',
+                                       'console': 'ChardevCommon',
                                        'spicevmc' : 'ChardevSpiceChannel',
                                        'spiceport' : 'ChardevSpicePort',
                                        'vc'     : 'ChardevVC',
diff --git a/qemu-char.c b/qemu-char.c
index af31102..e0147f3 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -420,7 +420,7 @@ static CharDriverState *qemu_chr_open_null(const char *id,
                                            Error **errp)
 {
     CharDriverState *chr;
-    ChardevCommon *common = qapi_ChardevDummy_base(backend->u.null);
+    ChardevCommon *common = backend->u.null;
 
     chr = qemu_chr_alloc(common, errp);
     if (!chr) {
@@ -1366,7 +1366,7 @@ static CharDriverState *qemu_chr_open_pty(const char *id,
     PtyCharDriver *s;
     int master_fd, slave_fd;
     char pty_name[PATH_MAX];
-    ChardevCommon *common = qapi_ChardevDummy_base(backend->u.pty);
+    ChardevCommon *common = backend->u.pty;
 
     master_fd = qemu_openpty_raw(&slave_fd, pty_name);
     if (master_fd < 0) {
@@ -2183,7 +2183,7 @@ static CharDriverState *qemu_chr_open_win_con(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevCommon *common = qapi_ChardevDummy_base(backend->u.console);
+    ChardevCommon *common = backend->u.console;
     return qemu_chr_open_win_file(GetStdHandle(STD_OUTPUT_HANDLE),
                                   common, errp);
 }
@@ -3817,7 +3817,7 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
     } else {
         ChardevCommon *cc = g_new0(ChardevCommon, 1);
         qemu_chr_parse_common(opts, cc);
-        backend->u.data = cc;
+        backend->u.null = cc; /* Any ChardevCommon member would work */
     }
 
     ret = qmp_chardev_add(bid ? bid : id, backend, errp);