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>

6 files changed, 45 insertions, 43 deletions

diff --git a/ui/console.c b/ui/console.c
index 8027ba7d8f..1fd4ea4d2e 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -2069,7 +2069,7 @@ static VcHandler *vc_handler = text_console_init;
 static CharDriverState *vc_init(const char *id, ChardevBackend *backend,
                                 ChardevReturn *ret, Error **errp)
 {
-    return vc_handler(backend->u.vc, errp);
+    return vc_handler(backend->u.vc.data, errp);
 }
 
 void register_vc_handler(VcHandler *handler)
@@ -2111,7 +2111,7 @@ static void qemu_chr_parse_vc(QemuOpts *opts, ChardevBackend *backend,
     int val;
     ChardevVC *vc;
 
-    vc = backend->u.vc = g_new0(ChardevVC, 1);
+    vc = backend->u.vc.data = g_new0(ChardevVC, 1);
     qemu_chr_parse_common(opts, qapi_ChardevVC_base(vc));
 
     val = qemu_opt_get_number(opts, "width", 0);
diff --git a/ui/input-keymap.c b/ui/input-keymap.c
index fd2c09ddc2..f1e700d720 100644
--- a/ui/input-keymap.c
+++ b/ui/input-keymap.c
@@ -141,10 +141,10 @@ static int number_to_qcode[0x100];
 int qemu_input_key_value_to_number(const KeyValue *value)
 {
     if (value->type == KEY_VALUE_KIND_QCODE) {
-        return qcode_to_number[value->u.qcode];
+        return qcode_to_number[value->u.qcode.data];
     } else {
         assert(value->type == KEY_VALUE_KIND_NUMBER);
-        return value->u.number;
+        return value->u.number.data;
     }
 }
 
@@ -168,10 +168,10 @@ int qemu_input_key_number_to_qcode(uint8_t nr)
 int qemu_input_key_value_to_qcode(const KeyValue *value)
 {
     if (value->type == KEY_VALUE_KIND_QCODE) {
-        return value->u.qcode;
+        return value->u.qcode.data;
     } else {
         assert(value->type == KEY_VALUE_KIND_NUMBER);
-        return qemu_input_key_number_to_qcode(value->u.number);
+        return qemu_input_key_number_to_qcode(value->u.number.data);
     }
 }
 
@@ -182,7 +182,7 @@ int qemu_input_key_value_to_scancode(const KeyValue *value, bool down,
     int count = 0;
 
     if (value->type == KEY_VALUE_KIND_QCODE &&
-        value->u.qcode == Q_KEY_CODE_PAUSE) {
+        value->u.qcode.data == Q_KEY_CODE_PAUSE) {
         /* specific case */
         int v = down ? 0 : 0x80;
         codes[count++] = 0xe1;
diff --git a/ui/input-legacy.c b/ui/input-legacy.c
index f1c5cb4a5e..7159747404 100644
--- a/ui/input-legacy.c
+++ b/ui/input-legacy.c
@@ -110,7 +110,7 @@ static void legacy_kbd_event(DeviceState *dev, QemuConsole *src,
 {
     QEMUPutKbdEntry *entry = (QEMUPutKbdEntry *)dev;
     int scancodes[3], i, count;
-    InputKeyEvent *key = evt->u.key;
+    InputKeyEvent *key = evt->u.key.data;
 
     if (!entry || !entry->put_kbd) {
         return;
@@ -156,7 +156,7 @@ static void legacy_mouse_event(DeviceState *dev, QemuConsole *src,
 
     switch (evt->type) {
     case INPUT_EVENT_KIND_BTN:
-        btn = evt->u.btn;
+        btn = evt->u.btn.data;
         if (btn->down) {
             s->buttons |= bmap[btn->button];
         } else {
@@ -178,11 +178,11 @@ static void legacy_mouse_event(DeviceState *dev, QemuConsole *src,
         }
         break;
     case INPUT_EVENT_KIND_ABS:
-        move = evt->u.abs;
+        move = evt->u.abs.data;
         s->axis[move->axis] = move->value;
         break;
     case INPUT_EVENT_KIND_REL:
-        move = evt->u.rel;
+        move = evt->u.rel.data;
         s->axis[move->axis] += move->value;
         break;
     default:
diff --git a/ui/input.c b/ui/input.c
index b035f86d37..ed88cda6d6 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -166,7 +166,7 @@ void qmp_input_send_event(bool has_device, const char *device,
 
 static void qemu_input_transform_abs_rotate(InputEvent *evt)
 {
-    InputMoveEvent *move = evt->u.abs;
+    InputMoveEvent *move = evt->u.abs.data;
     switch (graphic_rotate) {
     case 90:
         if (move->axis == INPUT_AXIS_X) {
@@ -203,16 +203,16 @@ static void qemu_input_event_trace(QemuConsole *src, InputEvent *evt)
     }
     switch (evt->type) {
     case INPUT_EVENT_KIND_KEY:
-        key = evt->u.key;
+        key = evt->u.key.data;
         switch (key->key->type) {
         case KEY_VALUE_KIND_NUMBER:
-            qcode = qemu_input_key_number_to_qcode(key->key->u.number);
+            qcode = qemu_input_key_number_to_qcode(key->key->u.number.data);
             name = QKeyCode_lookup[qcode];
-            trace_input_event_key_number(idx, key->key->u.number,
+            trace_input_event_key_number(idx, key->key->u.number.data,
                                          name, key->down);
             break;
         case KEY_VALUE_KIND_QCODE:
-            name = QKeyCode_lookup[key->key->u.qcode];
+            name = QKeyCode_lookup[key->key->u.qcode.data];
             trace_input_event_key_qcode(idx, name, key->down);
             break;
         case KEY_VALUE_KIND__MAX:
@@ -221,17 +221,17 @@ static void qemu_input_event_trace(QemuConsole *src, InputEvent *evt)
         }
         break;
     case INPUT_EVENT_KIND_BTN:
-        btn = evt->u.btn;
+        btn = evt->u.btn.data;
         name = InputButton_lookup[btn->button];
         trace_input_event_btn(idx, name, btn->down);
         break;
     case INPUT_EVENT_KIND_REL:
-        move = evt->u.rel;
+        move = evt->u.rel.data;
         name = InputAxis_lookup[move->axis];
         trace_input_event_rel(idx, name, move->value);
         break;
     case INPUT_EVENT_KIND_ABS:
-        move = evt->u.abs;
+        move = evt->u.abs.data;
         name = InputAxis_lookup[move->axis];
         trace_input_event_abs(idx, name, move->value);
         break;
@@ -366,10 +366,10 @@ void qemu_input_event_sync(void)
 InputEvent *qemu_input_event_new_key(KeyValue *key, bool down)
 {
     InputEvent *evt = g_new0(InputEvent, 1);
-    evt->u.key = g_new0(InputKeyEvent, 1);
+    evt->u.key.data = g_new0(InputKeyEvent, 1);
     evt->type = INPUT_EVENT_KIND_KEY;
-    evt->u.key->key = key;
-    evt->u.key->down = down;
+    evt->u.key.data->key = key;
+    evt->u.key.data->down = down;
     return evt;
 }
 
@@ -391,7 +391,7 @@ void qemu_input_event_send_key_number(QemuConsole *src, int num, bool down)
 {
     KeyValue *key = g_new0(KeyValue, 1);
     key->type = KEY_VALUE_KIND_NUMBER;
-    key->u.number = num;
+    key->u.number.data = num;
     qemu_input_event_send_key(src, key, down);
 }
 
@@ -399,7 +399,7 @@ void qemu_input_event_send_key_qcode(QemuConsole *src, QKeyCode q, bool down)
 {
     KeyValue *key = g_new0(KeyValue, 1);
     key->type = KEY_VALUE_KIND_QCODE;
-    key->u.qcode = q;
+    key->u.qcode.data = q;
     qemu_input_event_send_key(src, key, down);
 }
 
@@ -416,10 +416,10 @@ void qemu_input_event_send_key_delay(uint32_t delay_ms)
 InputEvent *qemu_input_event_new_btn(InputButton btn, bool down)
 {
     InputEvent *evt = g_new0(InputEvent, 1);
-    evt->u.btn = g_new0(InputBtnEvent, 1);
+    evt->u.btn.data = g_new0(InputBtnEvent, 1);
     evt->type = INPUT_EVENT_KIND_BTN;
-    evt->u.btn->button = btn;
-    evt->u.btn->down = down;
+    evt->u.btn.data->button = btn;
+    evt->u.btn.data->down = down;
     return evt;
 }
 
@@ -470,7 +470,7 @@ InputEvent *qemu_input_event_new_move(InputEventKind kind,
     InputMoveEvent *move = g_new0(InputMoveEvent, 1);
 
     evt->type = kind;
-    evt->u.rel = move; /* evt->u.rel is the same as evt->u.abs */
+    evt->u.rel.data = move; /* evt->u.rel is the same as evt->u.abs */
     move->axis = axis;
     move->value = value;
     return evt;
diff --git a/ui/vnc-auth-sasl.c b/ui/vnc-auth-sasl.c
index 13a59f500e..56e45e3473 100644
--- a/ui/vnc-auth-sasl.c
+++ b/ui/vnc-auth-sasl.c
@@ -513,7 +513,8 @@ vnc_socket_ip_addr_string(QIOChannelSocket *ioc,
         error_setg(errp, "Not an inet socket type");
         return NULL;
     }
-    ret = g_strdup_printf("%s;%s", addr->u.inet->host, addr->u.inet->port);
+    ret = g_strdup_printf("%s;%s", addr->u.inet.data->host,
+                          addr->u.inet.data->port);
     qapi_free_SocketAddress(addr);
     return ret;
 }
diff --git a/ui/vnc.c b/ui/vnc.c
index 9494a19ecf..6d39ddd3f9 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -112,9 +112,9 @@ static void vnc_init_basic_info(SocketAddress *addr,
 {
     switch (addr->type) {
     case SOCKET_ADDRESS_KIND_INET:
-        info->host = g_strdup(addr->u.inet->host);
-        info->service = g_strdup(addr->u.inet->port);
-        if (addr->u.inet->ipv6) {
+        info->host = g_strdup(addr->u.inet.data->host);
+        info->service = g_strdup(addr->u.inet.data->port);
+        if (addr->u.inet.data->ipv6) {
             info->family = NETWORK_ADDRESS_FAMILY_IPV6;
         } else {
             info->family = NETWORK_ADDRESS_FAMILY_IPV4;
@@ -123,7 +123,7 @@ static void vnc_init_basic_info(SocketAddress *addr,
 
     case SOCKET_ADDRESS_KIND_UNIX:
         info->host = g_strdup("");
-        info->service = g_strdup(addr->u.q_unix->path);
+        info->service = g_strdup(addr->u.q_unix.data->path);
         info->family = NETWORK_ADDRESS_FAMILY_UNIX;
         break;
 
@@ -385,9 +385,9 @@ VncInfo *qmp_query_vnc(Error **errp)
 
         switch (addr->type) {
         case SOCKET_ADDRESS_KIND_INET:
-            info->host = g_strdup(addr->u.inet->host);
-            info->service = g_strdup(addr->u.inet->port);
-            if (addr->u.inet->ipv6) {
+            info->host = g_strdup(addr->u.inet.data->host);
+            info->service = g_strdup(addr->u.inet.data->port);
+            if (addr->u.inet.data->ipv6) {
                 info->family = NETWORK_ADDRESS_FAMILY_IPV6;
             } else {
                 info->family = NETWORK_ADDRESS_FAMILY_IPV4;
@@ -396,7 +396,7 @@ VncInfo *qmp_query_vnc(Error **errp)
 
         case SOCKET_ADDRESS_KIND_UNIX:
             info->host = g_strdup("");
-            info->service = g_strdup(addr->u.q_unix->path);
+            info->service = g_strdup(addr->u.q_unix.data->path);
             info->family = NETWORK_ADDRESS_FAMILY_UNIX;
             break;
 
@@ -3192,7 +3192,8 @@ char *vnc_display_local_addr(const char *id)
         qapi_free_SocketAddress(addr);
         return NULL;
     }
-    ret = g_strdup_printf("%s;%s", addr->u.inet->host, addr->u.inet->port);
+    ret = g_strdup_printf("%s;%s", addr->u.inet.data->host,
+                          addr->u.inet.data->port);
     qapi_free_SocketAddress(addr);
 
     return ret;
@@ -3524,8 +3525,8 @@ void vnc_display_open(const char *id, Error **errp)
 
         if (strncmp(vnc, "unix:", 5) == 0) {
             saddr->type = SOCKET_ADDRESS_KIND_UNIX;
-            saddr->u.q_unix = g_new0(UnixSocketAddress, 1);
-            saddr->u.q_unix->path = g_strdup(vnc + 5);
+            saddr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
+            saddr->u.q_unix.data->path = g_strdup(vnc + 5);
 
             if (vs->ws_enabled) {
                 error_setg(errp, "UNIX sockets not supported with websock");
@@ -3535,7 +3536,7 @@ void vnc_display_open(const char *id, Error **errp)
             unsigned long long baseport;
             InetSocketAddress *inet;
             saddr->type = SOCKET_ADDRESS_KIND_INET;
-            inet = saddr->u.inet = g_new0(InetSocketAddress, 1);
+            inet = saddr->u.inet.data = g_new0(InetSocketAddress, 1);
             if (vnc[0] == '[' && vnc[hlen - 1] == ']') {
                 inet->host = g_strndup(vnc + 1, hlen - 2);
             } else {
@@ -3564,8 +3565,8 @@ void vnc_display_open(const char *id, Error **errp)
 
             if (vs->ws_enabled) {
                 wsaddr->type = SOCKET_ADDRESS_KIND_INET;
-                inet = wsaddr->u.inet = g_new0(InetSocketAddress, 1);
-                inet->host = g_strdup(saddr->u.inet->host);
+                inet = wsaddr->u.inet.data = g_new0(InetSocketAddress, 1);
+                inet->host = g_strdup(saddr->u.inet.data->host);
                 inet->port = g_strdup(websocket);
 
                 if (to) {