qapi: Don't special-case simple union wrappers

Simple unions were carrying a special case that hid their 'data'
QMP member from the resulting C struct, via the hack method
QAPISchemaObjectTypeVariant.simple_union_type().  But by using
the work we started by unboxing flat union and alternate
branches, coupled with the ability to visit the members of an
implicit type, we can now expose the simple union's implicit
type in qapi-types.h:

| struct q_obj_ImageInfoSpecificQCow2_wrapper {
|     ImageInfoSpecificQCow2 *data;
| };
|
| struct q_obj_ImageInfoSpecificVmdk_wrapper {
|     ImageInfoSpecificVmdk *data;
| };
...
| struct ImageInfoSpecific {
|     ImageInfoSpecificKind type;
|     union { /* union tag is @type */
|         void *data;
|-        ImageInfoSpecificQCow2 *qcow2;
|-        ImageInfoSpecificVmdk *vmdk;
|+        q_obj_ImageInfoSpecificQCow2_wrapper qcow2;
|+        q_obj_ImageInfoSpecificVmdk_wrapper vmdk;
|     } u;
| };

Doing this removes asymmetry between QAPI's QMP side and its
C side (both sides now expose 'data'), and means that the
treatment of a simple union as sugar for a flat union is now
equivalent in both languages (previously the two approaches used
a different layer of dereferencing, where the simple union could
be converted to a flat union with equivalent C layout but
different {} on the wire, or to an equivalent QMP wire form
but with different C representation).  Using the implicit type
also lets us get rid of the simple_union_type() hack.

Of course, now all clients of simple unions have to adjust from
using su->u.member to using su->u.member.data; while this touches
a number of files in the tree, some earlier cleanup patches
helped minimize the change to the initialization of a temporary
variable rather than every single member access.  The generated
qapi-visit.c code is also affected by the layout change:

|@@ -7393,10 +7393,10 @@ void visit_type_ImageInfoSpecific_member
|     }
|     switch (obj->type) {
|     case IMAGE_INFO_SPECIFIC_KIND_QCOW2:
|-        visit_type_ImageInfoSpecificQCow2(v, "data", &obj->u.qcow2, &err);
|+        visit_type_q_obj_ImageInfoSpecificQCow2_wrapper_members(v, &obj->u.qcow2, &err);
|         break;
|     case IMAGE_INFO_SPECIFIC_KIND_VMDK:
|-        visit_type_ImageInfoSpecificVmdk(v, "data", &obj->u.vmdk, &err);
|+        visit_type_q_obj_ImageInfoSpecificVmdk_wrapper_members(v, &obj->u.vmdk, &err);
|         break;
|     default:
|         abort();

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-13-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 42 insertions, 40 deletions

diff --git a/qemu-char.c b/qemu-char.c
index bfcf80dd10..f90e4c1208 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -98,16 +98,18 @@ static char *SocketAddress_to_str(const char *prefix, SocketAddress *addr,
     switch (addr->type) {
     case SOCKET_ADDRESS_KIND_INET:
         return g_strdup_printf("%s%s:%s:%s%s", prefix,
-                               is_telnet ? "telnet" : "tcp", addr->u.inet->host,
-                               addr->u.inet->port, is_listen ? ",server" : "");
+                               is_telnet ? "telnet" : "tcp",
+                               addr->u.inet.data->host,
+                               addr->u.inet.data->port,
+                               is_listen ? ",server" : "");
         break;
     case SOCKET_ADDRESS_KIND_UNIX:
         return g_strdup_printf("%sunix:%s%s", prefix,
-                               addr->u.q_unix->path,
+                               addr->u.q_unix.data->path,
                                is_listen ? ",server" : "");
         break;
     case SOCKET_ADDRESS_KIND_FD:
-        return g_strdup_printf("%sfd:%s%s", prefix, addr->u.fd->str,
+        return g_strdup_printf("%sfd:%s%s", prefix, addr->u.fd.data->str,
                                is_listen ? ",server" : "");
         break;
     default:
@@ -488,7 +490,7 @@ static CharDriverState *qemu_chr_open_null(const char *id,
                                            Error **errp)
 {
     CharDriverState *chr;
-    ChardevCommon *common = backend->u.null;
+    ChardevCommon *common = backend->u.null.data;
 
     chr = qemu_chr_alloc(common, errp);
     if (!chr) {
@@ -789,7 +791,7 @@ static CharDriverState *qemu_chr_open_mux(const char *id,
                                           ChardevBackend *backend,
                                           ChardevReturn *ret, Error **errp)
 {
-    ChardevMux *mux = backend->u.mux;
+    ChardevMux *mux = backend->u.mux.data;
     CharDriverState *chr, *drv;
     MuxDriver *d;
     ChardevCommon *common = qapi_ChardevMux_base(mux);
@@ -1106,7 +1108,7 @@ static CharDriverState *qemu_chr_open_pipe(const char *id,
                                            ChardevReturn *ret,
                                            Error **errp)
 {
-    ChardevHostdev *opts = backend->u.pipe;
+    ChardevHostdev *opts = backend->u.pipe.data;
     int fd_in, fd_out;
     char *filename_in;
     char *filename_out;
@@ -1188,7 +1190,7 @@ static CharDriverState *qemu_chr_open_stdio(const char *id,
                                             ChardevReturn *ret,
                                             Error **errp)
 {
-    ChardevStdio *opts = backend->u.stdio;
+    ChardevStdio *opts = backend->u.stdio.data;
     CharDriverState *chr;
     struct sigaction act;
     ChardevCommon *common = qapi_ChardevStdio_base(opts);
@@ -1434,7 +1436,7 @@ static CharDriverState *qemu_chr_open_pty(const char *id,
     PtyCharDriver *s;
     int master_fd, slave_fd;
     char pty_name[PATH_MAX];
-    ChardevCommon *common = backend->u.pty;
+    ChardevCommon *common = backend->u.pty.data;
 
     master_fd = qemu_openpty_raw(&slave_fd, pty_name);
     if (master_fd < 0) {
@@ -2205,7 +2207,7 @@ static CharDriverState *qemu_chr_open_pipe(const char *id,
                                            ChardevReturn *ret,
                                            Error **errp)
 {
-    ChardevHostdev *opts = backend->u.pipe;
+    ChardevHostdev *opts = backend->u.pipe.data;
     const char *filename = opts->device;
     CharDriverState *chr;
     WinCharState *s;
@@ -2251,7 +2253,7 @@ static CharDriverState *qemu_chr_open_win_con(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevCommon *common = backend->u.console;
+    ChardevCommon *common = backend->u.console.data;
     return qemu_chr_open_win_file(GetStdHandle(STD_OUTPUT_HANDLE),
                                   common, errp);
 }
@@ -2401,7 +2403,7 @@ static CharDriverState *qemu_chr_open_stdio(const char *id,
     WinStdioCharState *stdio;
     DWORD              dwMode;
     int                is_console = 0;
-    ChardevCommon *common = qapi_ChardevStdio_base(backend->u.stdio);
+    ChardevCommon *common = qapi_ChardevStdio_base(backend->u.stdio.data);
 
     chr   = qemu_chr_alloc(common, errp);
     if (!chr) {
@@ -3042,7 +3044,7 @@ static void tcp_chr_tls_init(CharDriverState *chr)
     } else {
         tioc = qio_channel_tls_new_client(
             s->ioc, s->tls_creds,
-            s->addr->u.inet->host,
+            s->addr->u.inet.data->host,
             &err);
     }
     if (tioc == NULL) {
@@ -3249,7 +3251,7 @@ static CharDriverState *qemu_chr_open_ringbuf(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevRingbuf *opts = backend->u.ringbuf;
+    ChardevRingbuf *opts = backend->u.ringbuf.data;
     ChardevCommon *common = qapi_ChardevRingbuf_base(opts);
     CharDriverState *chr;
     RingBufCharDriver *d;
@@ -3546,7 +3548,7 @@ static void qemu_chr_parse_file_out(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: file: no filename given");
         return;
     }
-    file = backend->u.file = g_new0(ChardevFile, 1);
+    file = backend->u.file.data = g_new0(ChardevFile, 1);
     qemu_chr_parse_common(opts, qapi_ChardevFile_base(file));
     file->out = g_strdup(path);
 
@@ -3559,7 +3561,7 @@ static void qemu_chr_parse_stdio(QemuOpts *opts, ChardevBackend *backend,
 {
     ChardevStdio *stdio;
 
-    stdio = backend->u.stdio = g_new0(ChardevStdio, 1);
+    stdio = backend->u.stdio.data = g_new0(ChardevStdio, 1);
     qemu_chr_parse_common(opts, qapi_ChardevStdio_base(stdio));
     stdio->has_signal = true;
     stdio->signal = qemu_opt_get_bool(opts, "signal", true);
@@ -3576,7 +3578,7 @@ static void qemu_chr_parse_serial(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: serial/tty: no device path given");
         return;
     }
-    serial = backend->u.serial = g_new0(ChardevHostdev, 1);
+    serial = backend->u.serial.data = g_new0(ChardevHostdev, 1);
     qemu_chr_parse_common(opts, qapi_ChardevHostdev_base(serial));
     serial->device = g_strdup(device);
 }
@@ -3593,7 +3595,7 @@ static void qemu_chr_parse_parallel(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: parallel: no device path given");
         return;
     }
-    parallel = backend->u.parallel = g_new0(ChardevHostdev, 1);
+    parallel = backend->u.parallel.data = g_new0(ChardevHostdev, 1);
     qemu_chr_parse_common(opts, qapi_ChardevHostdev_base(parallel));
     parallel->device = g_strdup(device);
 }
@@ -3609,7 +3611,7 @@ static void qemu_chr_parse_pipe(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: pipe: no device path given");
         return;
     }
-    dev = backend->u.pipe = g_new0(ChardevHostdev, 1);
+    dev = backend->u.pipe.data = g_new0(ChardevHostdev, 1);
     qemu_chr_parse_common(opts, qapi_ChardevHostdev_base(dev));
     dev->device = g_strdup(device);
 }
@@ -3620,7 +3622,7 @@ static void qemu_chr_parse_ringbuf(QemuOpts *opts, ChardevBackend *backend,
     int val;
     ChardevRingbuf *ringbuf;
 
-    ringbuf = backend->u.ringbuf = g_new0(ChardevRingbuf, 1);
+    ringbuf = backend->u.ringbuf.data = g_new0(ChardevRingbuf, 1);
     qemu_chr_parse_common(opts, qapi_ChardevRingbuf_base(ringbuf));
 
     val = qemu_opt_get_size(opts, "size", 0);
@@ -3640,7 +3642,7 @@ static void qemu_chr_parse_mux(QemuOpts *opts, ChardevBackend *backend,
         error_setg(errp, "chardev: mux: no chardev given");
         return;
     }
-    mux = backend->u.mux = g_new0(ChardevMux, 1);
+    mux = backend->u.mux.data = g_new0(ChardevMux, 1);
     qemu_chr_parse_common(opts, qapi_ChardevMux_base(mux));
     mux->chardev = g_strdup(chardev);
 }
@@ -3676,7 +3678,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
         }
     }
 
-    sock = backend->u.socket = g_new0(ChardevSocket, 1);
+    sock = backend->u.socket.data = g_new0(ChardevSocket, 1);
     qemu_chr_parse_common(opts, qapi_ChardevSocket_base(sock));
 
     sock->has_nodelay = true;
@@ -3695,12 +3697,12 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
     if (path) {
         UnixSocketAddress *q_unix;
         addr->type = SOCKET_ADDRESS_KIND_UNIX;
-        q_unix = addr->u.q_unix = g_new0(UnixSocketAddress, 1);
+        q_unix = addr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
         q_unix->path = g_strdup(path);
     } else {
         addr->type = SOCKET_ADDRESS_KIND_INET;
-        addr->u.inet = g_new(InetSocketAddress, 1);
-        *addr->u.inet = (InetSocketAddress) {
+        addr->u.inet.data = g_new(InetSocketAddress, 1);
+        *addr->u.inet.data = (InetSocketAddress) {
             .host = g_strdup(host),
             .port = g_strdup(port),
             .has_to = qemu_opt_get(opts, "to"),
@@ -3743,13 +3745,13 @@ static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
         has_local = true;
     }
 
-    udp = backend->u.udp = g_new0(ChardevUdp, 1);
+    udp = backend->u.udp.data = g_new0(ChardevUdp, 1);
     qemu_chr_parse_common(opts, qapi_ChardevUdp_base(udp));
 
     addr = g_new0(SocketAddress, 1);
     addr->type = SOCKET_ADDRESS_KIND_INET;
-    addr->u.inet = g_new(InetSocketAddress, 1);
-    *addr->u.inet = (InetSocketAddress) {
+    addr->u.inet.data = g_new(InetSocketAddress, 1);
+    *addr->u.inet.data = (InetSocketAddress) {
         .host = g_strdup(host),
         .port = g_strdup(port),
         .has_ipv4 = qemu_opt_get(opts, "ipv4"),
@@ -3763,8 +3765,8 @@ static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
         udp->has_local = true;
         addr = g_new0(SocketAddress, 1);
         addr->type = SOCKET_ADDRESS_KIND_INET;
-        addr->u.inet = g_new(InetSocketAddress, 1);
-        *addr->u.inet = (InetSocketAddress) {
+        addr->u.inet.data = g_new(InetSocketAddress, 1);
+        *addr->u.inet.data = (InetSocketAddress) {
             .host = g_strdup(localaddr),
             .port = g_strdup(localport),
         };
@@ -3851,7 +3853,7 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
     } else {
         ChardevCommon *cc = g_new0(ChardevCommon, 1);
         qemu_chr_parse_common(opts, cc);
-        backend->u.null = cc; /* Any ChardevCommon member would work */
+        backend->u.null.data = cc; /* Any ChardevCommon member would work */
     }
 
     ret = qmp_chardev_add(bid ? bid : id, backend, errp);
@@ -3863,9 +3865,9 @@ CharDriverState *qemu_chr_new_from_opts(QemuOpts *opts,
         qapi_free_ChardevBackend(backend);
         qapi_free_ChardevReturn(ret);
         backend = g_new0(ChardevBackend, 1);
-        backend->u.mux = g_new0(ChardevMux, 1);
+        backend->u.mux.data = g_new0(ChardevMux, 1);
         backend->type = CHARDEV_BACKEND_KIND_MUX;
-        backend->u.mux->chardev = g_strdup(bid);
+        backend->u.mux.data->chardev = g_strdup(bid);
         ret = qmp_chardev_add(id, backend, errp);
         if (!ret) {
             chr = qemu_chr_find(bid);
@@ -4194,7 +4196,7 @@ static CharDriverState *qmp_chardev_open_file(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevFile *file = backend->u.file;
+    ChardevFile *file = backend->u.file.data;
     ChardevCommon *common = qapi_ChardevFile_base(file);
     HANDLE out;
 
@@ -4217,7 +4219,7 @@ static CharDriverState *qmp_chardev_open_serial(const char *id,
                                                 ChardevReturn *ret,
                                                 Error **errp)
 {
-    ChardevHostdev *serial = backend->u.serial;
+    ChardevHostdev *serial = backend->u.serial.data;
     ChardevCommon *common = qapi_ChardevHostdev_base(serial);
     return qemu_chr_open_win_path(serial->device, common, errp);
 }
@@ -4241,7 +4243,7 @@ static CharDriverState *qmp_chardev_open_file(const char *id,
                                               ChardevReturn *ret,
                                               Error **errp)
 {
-    ChardevFile *file = backend->u.file;
+    ChardevFile *file = backend->u.file.data;
     ChardevCommon *common = qapi_ChardevFile_base(file);
     int flags, in = -1, out;
 
@@ -4275,7 +4277,7 @@ static CharDriverState *qmp_chardev_open_serial(const char *id,
                                                 ChardevReturn *ret,
                                                 Error **errp)
 {
-    ChardevHostdev *serial = backend->u.serial;
+    ChardevHostdev *serial = backend->u.serial.data;
     ChardevCommon *common = qapi_ChardevHostdev_base(serial);
     int fd;
 
@@ -4294,7 +4296,7 @@ static CharDriverState *qmp_chardev_open_parallel(const char *id,
                                                   ChardevReturn *ret,
                                                   Error **errp)
 {
-    ChardevHostdev *parallel = backend->u.parallel;
+    ChardevHostdev *parallel = backend->u.parallel.data;
     ChardevCommon *common = qapi_ChardevHostdev_base(parallel);
     int fd;
 
@@ -4335,7 +4337,7 @@ static CharDriverState *qmp_chardev_open_socket(const char *id,
 {
     CharDriverState *chr;
     TCPCharDriver *s;
-    ChardevSocket *sock = backend->u.socket;
+    ChardevSocket *sock = backend->u.socket.data;
     SocketAddress *addr = sock->addr;
     bool do_nodelay     = sock->has_nodelay ? sock->nodelay : false;
     bool is_listen      = sock->has_server  ? sock->server  : true;
@@ -4460,7 +4462,7 @@ static CharDriverState *qmp_chardev_open_udp(const char *id,
                                              ChardevReturn *ret,
                                              Error **errp)
 {
-    ChardevUdp *udp = backend->u.udp;
+    ChardevUdp *udp = backend->u.udp.data;
     ChardevCommon *common = qapi_ChardevUdp_base(udp);
     QIOChannelSocket *sioc = qio_channel_socket_new();