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 374562a483..c11320eecf 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 9a82efda9e..5e1833c6e6 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 42fd61b2ce..362c9d816a 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 af311023d6..e0147f3e8b 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);