qapi: Convert simple union SocketAddressLegacy to flat one

Simple unions predate flat unions.  Having both complicates the QAPI
schema language and the QAPI generator.  We haven't been using simple
unions in new code for a long time, because they are less flexible and
somewhat awkward on the wire.

To prepare for their removal, convert simple union SocketAddressLegacy
to an equivalent flat one, with existing enum SocketAddressType
replacing implicit enum type SocketAddressLegacyKind.  Adds some
boilerplate to the schema, which is a bit ugly, but a lot easier to
maintain than the simple union feature.

Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210917143134.412106-9-armbru@redhat.com>

diff --git a/chardev/char-socket.c b/chardev/char-socket.c
index c43668cc159ead7482400945e4429703e2a19290..836cfa0bc21be39ea1bcc6ab4a48eafbd2ef0bdf 100644 (file)
--- a/chardev/char-socket.c
+++ b/chardev/char-socket.c
@@ -1520,7 +1520,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
     addr = g_new0(SocketAddressLegacy, 1);
     if (path) {
         UnixSocketAddress *q_unix;
-        addr->type = SOCKET_ADDRESS_LEGACY_KIND_UNIX;
+        addr->type = SOCKET_ADDRESS_TYPE_UNIX;
         q_unix = addr->u.q_unix.data = g_new0(UnixSocketAddress, 1);
         q_unix->path = g_strdup(path);
 #ifdef CONFIG_LINUX
@@ -1530,7 +1530,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
         q_unix->abstract = abstract;
 #endif
     } else if (host) {
-        addr->type = SOCKET_ADDRESS_LEGACY_KIND_INET;
+        addr->type = SOCKET_ADDRESS_TYPE_INET;
         addr->u.inet.data = g_new(InetSocketAddress, 1);
         *addr->u.inet.data = (InetSocketAddress) {
             .host = g_strdup(host),
@@ -1543,7 +1543,7 @@ static void qemu_chr_parse_socket(QemuOpts *opts, ChardevBackend *backend,
             .ipv6 = qemu_opt_get_bool(opts, "ipv6", 0),
         };
     } else if (fd) {
-        addr->type = SOCKET_ADDRESS_LEGACY_KIND_FD;
+        addr->type = SOCKET_ADDRESS_TYPE_FD;
         addr->u.fd.data = g_new(String, 1);
         addr->u.fd.data->str = g_strdup(fd);
     } else {

diff --git a/chardev/char-udp.c b/chardev/char-udp.c
index 16b5dbce5824327f649fd2a7a9890a93d3bf7402..6756e69924cb772d2ebd50806338e7d4dd252eb6 100644 (file)
--- a/chardev/char-udp.c
+++ b/chardev/char-udp.c
@@ -165,7 +165,7 @@ static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
     qemu_chr_parse_common(opts, qapi_ChardevUdp_base(udp));
 
     addr = g_new0(SocketAddressLegacy, 1);
-    addr->type = SOCKET_ADDRESS_LEGACY_KIND_INET;
+    addr->type = SOCKET_ADDRESS_TYPE_INET;
     addr->u.inet.data = g_new(InetSocketAddress, 1);
     *addr->u.inet.data = (InetSocketAddress) {
         .host = g_strdup(host),
@@ -180,7 +180,7 @@ static void qemu_chr_parse_udp(QemuOpts *opts, ChardevBackend *backend,
     if (has_local) {
         udp->has_local = true;
         addr = g_new0(SocketAddressLegacy, 1);
-        addr->type = SOCKET_ADDRESS_LEGACY_KIND_INET;
+        addr->type = SOCKET_ADDRESS_TYPE_INET;
         addr->u.inet.data = g_new(InetSocketAddress, 1);
         *addr->u.inet.data = (InetSocketAddress) {
             .host = g_strdup(localaddr),

diff --git a/qapi/sockets.json b/qapi/sockets.json
index 7866dc27d6c9a731e8b6a8bc6e80670bb96323eb..ef4b16d6f28a94e521308b731e96ad9b3df49b48 100644 (file)
--- a/qapi/sockets.json
+++ b/qapi/sockets.json
@@ -110,6 +110,38 @@
     'cid': 'str',
     'port': 'str' } }
 
+##
+# @InetSocketAddressWrapper:
+#
+# Since: 1.3
+##
+{ 'struct': 'InetSocketAddressWrapper',
+  'data': { 'data': 'InetSocketAddress' } }
+
+##
+# @UnixSocketAddressWrapper:
+#
+# Since: 1.3
+##
+{ 'struct': 'UnixSocketAddressWrapper',
+  'data': { 'data': 'UnixSocketAddress' } }
+
+##
+# @VsockSocketAddressWrapper:
+#
+# Since: 2.8
+##
+{ 'struct': 'VsockSocketAddressWrapper',
+  'data': { 'data': 'VsockSocketAddress' } }
+
+##
+# @StringWrapper:
+#
+# Since: 1.3
+##
+{ 'struct': 'StringWrapper',
+  'data': { 'data': 'String' } }
+
 ##
 # @SocketAddressLegacy:
 #
@@ -117,18 +149,18 @@
 #
 # Note: This type is deprecated in favor of SocketAddress.  The
 #       difference between SocketAddressLegacy and SocketAddress is that the
-#       latter is a flat union rather than a simple union. Flat is nicer
-#       because it avoids nesting on the wire, i.e. that form has fewer {}.
-
+#       latter is has fewer {} on the wire.
 #
 # Since: 1.3
 ##
 { 'union': 'SocketAddressLegacy',
+  'base': { 'type': 'SocketAddressType' },
+  'discriminator': 'type',
   'data': {
-    'inet': 'InetSocketAddress',
-    'unix': 'UnixSocketAddress',
-    'vsock': 'VsockSocketAddress',
-    'fd': 'String' } }
+    'inet': 'InetSocketAddressWrapper',
+    'unix': 'UnixSocketAddressWrapper',
+    'vsock': 'VsockSocketAddressWrapper',
+    'fd': 'StringWrapper' } }
 
 ##
 # @SocketAddressType:

diff --git a/tests/unit/test-yank.c b/tests/unit/test-yank.c
index 2383d2908c0bb3582d29fb870721158a70e1d9dd..e6c036a64d9c249ba25cf3e55119d0b35598d5bc 100644 (file)
--- a/tests/unit/test-yank.c
+++ b/tests/unit/test-yank.c
@@ -88,7 +88,7 @@ static void char_change_test(gconstpointer opaque)
             .type = CHARDEV_BACKEND_KIND_SOCKET,
             .u.socket.data = &(ChardevSocket) {
                 .addr = &(SocketAddressLegacy) {
-                    .type = SOCKET_ADDRESS_LEGACY_KIND_INET,
+                    .type = SOCKET_ADDRESS_TYPE_INET,
                     .u.inet.data = &addr->u.inet
                 },
                 .has_server = true,
@@ -102,7 +102,7 @@ static void char_change_test(gconstpointer opaque)
             .type = CHARDEV_BACKEND_KIND_UDP,
             .u.udp.data = &(ChardevUdp) {
                 .remote = &(SocketAddressLegacy) {
-                    .type = SOCKET_ADDRESS_LEGACY_KIND_UNIX,
+                    .type = SOCKET_ADDRESS_TYPE_UNIX,
                     .u.q_unix.data = &(UnixSocketAddress) {
                         .path = (char *)""
                     }
@@ -114,7 +114,7 @@ static void char_change_test(gconstpointer opaque)
             .type = CHARDEV_BACKEND_KIND_SOCKET,
             .u.socket.data = &(ChardevSocket) {
                 .addr = &(SocketAddressLegacy) {
-                    .type = SOCKET_ADDRESS_LEGACY_KIND_INET,
+                    .type = SOCKET_ADDRESS_TYPE_INET,
                     .u.inet.data = &(InetSocketAddress) {
                         .host = (char *)"127.0.0.1",
                         .port = (char *)"0"

diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c
index c5043999e9d47116a89511d82b231ada09e3c63a..72216ef9808d12aa37671abe83a77fd5ae7bde7e 100644 (file)
--- a/util/qemu-sockets.c
+++ b/util/qemu-sockets.c
@@ -1455,22 +1455,22 @@ SocketAddress *socket_address_flatten(SocketAddressLegacy *addr_legacy)
     addr = g_new(SocketAddress, 1);
 
     switch (addr_legacy->type) {
-    case SOCKET_ADDRESS_LEGACY_KIND_INET:
+    case SOCKET_ADDRESS_TYPE_INET:
         addr->type = SOCKET_ADDRESS_TYPE_INET;
         QAPI_CLONE_MEMBERS(InetSocketAddress, &addr->u.inet,
                            addr_legacy->u.inet.data);
         break;
-    case SOCKET_ADDRESS_LEGACY_KIND_UNIX:
+    case SOCKET_ADDRESS_TYPE_UNIX:
         addr->type = SOCKET_ADDRESS_TYPE_UNIX;
         QAPI_CLONE_MEMBERS(UnixSocketAddress, &addr->u.q_unix,
                            addr_legacy->u.q_unix.data);
         break;
-    case SOCKET_ADDRESS_LEGACY_KIND_VSOCK:
+    case SOCKET_ADDRESS_TYPE_VSOCK:
         addr->type = SOCKET_ADDRESS_TYPE_VSOCK;
         QAPI_CLONE_MEMBERS(VsockSocketAddress, &addr->u.vsock,
                            addr_legacy->u.vsock.data);
         break;
-    case SOCKET_ADDRESS_LEGACY_KIND_FD:
+    case SOCKET_ADDRESS_TYPE_FD:
         addr->type = SOCKET_ADDRESS_TYPE_FD;
         QAPI_CLONE_MEMBERS(String, &addr->u.fd, addr_legacy->u.fd.data);
         break;