compiler: support Darwin weak references

Weakrefs only tell you if the symbol was defined elsewhere, so you
need a further check at runtime to pick the default definition
when needed.

This could be automated by the compiler, but it does not do it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 22 insertions, 18 deletions

diff --git a/qemu-sockets.c b/qemu-sockets.c
index f2a6371..abcd791 100644
--- a/qemu-sockets.c
+++ b/qemu-sockets.c
@@ -61,6 +61,28 @@ static QemuOptsList dummy_opts = {
     },
 };
 
+static int default_monitor_get_fd(Monitor *mon, const char *name, Error **errp)
+{
+    error_setg(errp, "only QEMU supports file descriptor passing");
+    return -1;
+}
+QEMU_WEAK_ALIAS(monitor_get_fd, default_monitor_get_fd);
+#define monitor_get_fd \
+    QEMU_WEAK_REF(monitor_get_fd, default_monitor_get_fd)
+
+static int default_qemu_set_fd_handler2(int fd,
+                                        IOCanReadHandler *fd_read_poll,
+                                        IOHandler *fd_read,
+                                        IOHandler *fd_write,
+                                        void *opaque)
+
+{
+    abort();
+}
+QEMU_WEAK_ALIAS(qemu_set_fd_handler2, default_qemu_set_fd_handler2);
+#define qemu_set_fd_handler2 \
+    QEMU_WEAK_REF(qemu_set_fd_handler2, default_qemu_set_fd_handler2)
+
 static int inet_getport(struct addrinfo *e)
 {
     struct sockaddr_in *i4;
@@ -967,21 +989,3 @@ int socket_init(void)
 #endif
     return 0;
 }
-
-static int default_monitor_get_fd(Monitor *mon, const char *name, Error **errp)
-{
-    error_setg(errp, "only QEMU supports file descriptor passing");
-    return -1;
-}
-QEMU_WEAK_ALIAS(monitor_get_fd, default_monitor_get_fd);
-
-static int default_qemu_set_fd_handler2(int fd,
-                                        IOCanReadHandler *fd_read_poll,
-                                        IOHandler *fd_read,
-                                        IOHandler *fd_write,
-                                        void *opaque)
-
-{
-    abort();
-}
-QEMU_WEAK_ALIAS(qemu_set_fd_handler2, default_qemu_set_fd_handler2);