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, 32 insertions, 24 deletions

diff --git a/osdep.c b/osdep.c
index a87d4a4..2f7a491 100644
--- a/osdep.c
+++ b/osdep.c
@@ -54,6 +54,38 @@ static bool fips_enabled = false;
 
 static const char *qemu_version = QEMU_VERSION;
 
+static int default_fdset_get_fd(int64_t fdset_id, int flags)
+{
+    return -1;
+}
+QEMU_WEAK_ALIAS(monitor_fdset_get_fd, default_fdset_get_fd);
+#define monitor_fdset_get_fd \
+    QEMU_WEAK_REF(monitor_fdset_get_fd, default_fdset_get_fd)
+
+static int default_fdset_dup_fd_add(int64_t fdset_id, int dup_fd)
+{
+    return -1;
+}
+QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_add, default_fdset_dup_fd_add);
+#define monitor_fdset_dup_fd_add \
+    QEMU_WEAK_REF(monitor_fdset_dup_fd_add, default_fdset_dup_fd_add)
+
+static int default_fdset_dup_fd_remove(int dup_fd)
+{
+    return -1;
+}
+QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_remove, default_fdset_dup_fd_remove);
+#define monitor_fdset_dup_fd_remove \
+    QEMU_WEAK_REF(monitor_fdset_dup_fd_remove, default_fdset_dup_fd_remove)
+
+static int default_fdset_dup_fd_find(int dup_fd)
+{
+    return -1;
+}
+QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_find, default_fdset_dup_fd_find);
+#define monitor_fdset_dup_fd_find \
+    QEMU_WEAK_REF(monitor_fdset_dup_fd_remove, default_fdset_dup_fd_find)
+
 int socket_set_cork(int fd, int v)
 {
 #if defined(SOL_TCP) && defined(TCP_CORK)
@@ -400,27 +432,3 @@ bool fips_get_state(void)
     return fips_enabled;
 }
 
-
-static int default_fdset_get_fd(int64_t fdset_id, int flags)
-{
-    return -1;
-}
-QEMU_WEAK_ALIAS(monitor_fdset_get_fd, default_fdset_get_fd);
-
-static int default_fdset_dup_fd_add(int64_t fdset_id, int dup_fd)
-{
-    return -1;
-}
-QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_add, default_fdset_dup_fd_add);
-
-static int default_fdset_dup_fd_remove(int dup_fd)
-{
-    return -1;
-}
-QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_remove, default_fdset_dup_fd_remove);
-
-static int default_fdset_dup_fd_find(int dup_fd)
-{
-    return -1;
-}
-QEMU_WEAK_ALIAS(monitor_fdset_dup_fd_find, default_fdset_dup_fd_find);