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, 7 insertions, 5 deletions

diff --git a/oslib-win32.c b/oslib-win32.c
index 9ca83df011..326a2bddb3 100644
--- a/oslib-win32.c
+++ b/oslib-win32.c
@@ -32,6 +32,13 @@
 #include "trace.h"
 #include "qemu_socket.h"
 
+static void default_qemu_fd_register(int fd)
+{
+}
+QEMU_WEAK_ALIAS(qemu_fd_register, default_qemu_fd_register);
+#define qemu_fd_register \
+    QEMU_WEAK_REF(qemu_fd_register, default_qemu_fd_register)
+
 void *qemu_oom_check(void *ptr)
 {
     if (ptr == NULL) {
@@ -150,8 +157,3 @@ int qemu_get_thread_id(void)
 {
     return GetCurrentThreadId();
 }
-
-static void default_qemu_fd_register(int fd)
-{
-}
-QEMU_WEAK_ALIAS(qemu_fd_register, default_qemu_fd_register);