Re: [Qemu-devel] [PATCH v2 05/39] fdsets: use weak aliases instead of qemu-tool.c/qemu-user.c

[Peter Maydell]

On 16 November 2012 09:35, Paolo Bonzini <address@hidden> wrote:
> Ok, I reproduced the original binutils bug, and found a typo in the
> weakrefs implementation.  Does this work for you?
>
> diff --git a/compiler.h b/compiler.h
> index 55d7d74..d552757 100644
> --- a/compiler.h
> +++ b/compiler.h
> @@ -50,11 +50,12 @@
>  #   define __printf__ __gnu_printf__
>  #  endif
>  # endif
> -# if defined(__APPLE__)
> +# if defined(__APPLE__) || defined(_WIN32)
>  #  define QEMU_WEAK_ALIAS(newname, oldname) \
> -        static typeof(oldname) weak_##newname __attribute__((unused, 
> weakref(#oldname)))
> +        static typeof(oldname) weak_##newname __attribute__((unused, 
> weakref(#newname)))
>  #  define QEMU_WEAK_REF(newname, oldname) (weak_##newname ? weak_##newname : 
> oldname)
>  # else
> +#error
>  #  define QEMU_WEAK_ALIAS(newname, oldname) \
>          typeof(oldname) newname __attribute__((weak, alias (#oldname)))
>  #  define QEMU_WEAK_REF(newname, oldname) newname

This change makes compilation fail with clang:
  LINK  qemu-ga
Undefined symbols for architecture x86_64:
  "_monitor_fdset_dup_fd_add", referenced from:
      _qemu_open in osdep.o
  "_monitor_fdset_dup_fd_remove", referenced from:
      _qemu_close in osdep.o
  "_monitor_fdset_get_fd", referenced from:
      _qemu_open in osdep.o
  "_monitor_get_fd", referenced from:
      _socket_connect in qemu-sockets.o
      _socket_listen in qemu-sockets.o
  "_qemu_set_fd_handler2", referenced from:
      _inet_connect_addr in qemu-sockets.o
      _unix_connect_opts in qemu-sockets.o
      _wait_for_connect in qemu-sockets.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

(clang builds OK with current git master.)

-- PMM