[v3,09/10] chardev: Drop useless ChardevDummy type

Commit Message

Eric Blake March 3, 2016, 4:16 p.m. UTC

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 <[e-mail]>
Reviewed-by: Daniel P. Berrange <[e-mail]>

---
v3: no change
v2: add R-b
---
 backends/baum.c    |  2 +-
 backends/msmouse.c |  2 +-
 qemu-char.c        |  6 +++---
 qapi-schema.json   | 15 ++++++---------
 4 files changed, 11 insertions(+), 14 deletions(-)

Comments

Markus Armbruster March 4, 2016, 2:40 p.m. UTC | #1

Eric Blake <[e-mail]> writes:

> 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 <[e-mail]>
> Reviewed-by: Daniel P. Berrange <[e-mail]>

Doesn't compile with MinGW:

qemu/qemu-char.c: In function 'qemu_chr_open_win_con':
qemu/qemu-char.c:2186:29: warning: implicit declaration of function 'qapi_ChardevDummy_base' [-Wimplicit-function-declaration]
     ChardevCommon *common = qapi_ChardevDummy_base(backend->u.console);
                             ^
qemu/qemu-char.c:2186:5: warning: nested extern declaration of 'qapi_ChardevDummy_base' [-Wnested-externs]
     ChardevCommon *common = qapi_ChardevDummy_base(backend->u.console);
     ^
qemu/qemu-char.c:2186:29: warning: initialization makes pointer from integer without a cast [-Wint-conversion]
     ChardevCommon *common = qapi_ChardevDummy_base(backend->u.console);
                             ^

Eric Blake March 4, 2016, 3:25 p.m. UTC | #2

On 03/04/2016 07:40 AM, Markus Armbruster wrote:
> Eric Blake <[e-mail]> writes:
> 
>> 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 <[e-mail]>
>> Reviewed-by: Daniel P. Berrange <[e-mail]>
> 
> Doesn't compile with MinGW:
> 
> qemu/qemu-char.c: In function 'qemu_chr_open_win_con':
> qemu/qemu-char.c:2186:29: warning: implicit declaration of function 'qapi_ChardevDummy_base' [-Wimplicit-function-declaration]
>      ChardevCommon *common = qapi_ChardevDummy_base(backend->u.console);
>                              ^

The curse of not compiling all the backends, and failing to grep for
ChardevDummy.  Replacement patch coming up soon.

Patch

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/qemu-char.c b/qemu-char.c
index af31102..6eb10e6 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) {
@@ -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);
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',