mach, hurd: Cast through uintptr_t

When casting between a pointer and an integer of a different size, GCC
emits a warning (which is escalated to a build failure by -Werror).
Indeed, if what you start with is a pointer, which you then cast to a
shorter integer and then back again, you're going to cut off some bits
of the pointer.

But if you start with an integer (such as mach_port_t), then cast it to
a longer pointer (void *), and then back to a shorter integer, you are
fine. To keep GCC happy, cast through an intermediary uintptr_t, which
is always the same size as a pointer.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-Id: <20230212111044.610942-4-bugaevc@gmail.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/hurd/hurd/port.h b/hurd/hurd/port.h
index fdba8db5ed..1e473978d8 100644
--- a/hurd/hurd/port.h
+++ b/hurd/hurd/port.h
@@ -96,7 +96,7 @@ _hurd_port_locked_get (struct hurd_port *port,
   if (result != MACH_PORT_NULL)
     {
       link->cleanup = &_hurd_port_cleanup;
-      link->cleanup_data = (void *) result;
+      link->cleanup_data = (void *) (uintptr_t) result;
       _hurd_userlink_link (&port->users, link);
     }
   __spin_unlock (&port->lock);