xace: typesafe hook function for XACE_KEY_AVAIL

he generic XaceHook() call isn't typesafe (und unnecessarily slow).
Better add an explicit function, just like we already have for others.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1556>

Xext/xace.c

@@ -136,43 +136,11 @@ int XaceHookAuthAvail(ClientPtr client, XID authId)
     return Success;
 }
 
-/* Entry point for hook functions.  Called by Xserver.
+int XaceHookKeyAvail(xEventPtr ev, DeviceIntPtr dev, int count)
- */
-int
-XaceHook(int hook, ...)
 {
-    union {
+    XaceKeyAvailRec rec = { ev, dev, count };
-        XaceKeyAvailRec key;
+    CallCallbacks(&XaceHooks[XACE_KEY_AVAIL], &rec);
-    } u;
-    int *prv = NULL;            /* points to return value from callback */
-    va_list ap;                 /* argument list */
-
-    if (!XaceHooks[hook])
     return Success;
-
-    va_start(ap, hook);
-
-    /* Marshal arguments for passing to callback.
-     * Each callback has its own case, which sets up a structure to hold
-     * the arguments and integer return parameter, or in some cases just
-     * sets calldata directly to a single argument (with no return result)
-     */
-    switch (hook) {
-    case XACE_KEY_AVAIL:
-        u.key.event = va_arg(ap, xEventPtr);
-        u.key.keybd = va_arg(ap, DeviceIntPtr);
-        u.key.count = va_arg(ap, int);
-
-        break;
-    default:
-        va_end(ap);
-        return 0;               /* unimplemented hook number */
-    }
-    va_end(ap);
-
-    /* call callbacks and return result, if any. */
-    CallCallbacks(&XaceHooks[hook], &u);
-    return prv ? *prv : Success;
 }
 
 /* XaceHookIsSet

Xext/xace.h

@@ -94,6 +94,7 @@ int XaceHookServerAccess(ClientPtr client, Mask access_mode);
 int XaceHookScreenAccess(ClientPtr client, ScreenPtr screen, Mask access_mode);
 int XaceHookScreensaverAccess(ClientPtr client, ScreenPtr screen, Mask access_mode);
 int XaceHookAuthAvail(ClientPtr client, XID authId);
+int XaceHookKeyAvail(xEventPtr ev, DeviceIntPtr dev, int count);
 
 
 /* Register a callback for a given hook.
@@ -129,14 +130,12 @@ void XaceCensorImage(ClientPtr client,
 /* Define calls away when XACE is not being built. */
 
 #ifdef __GNUC__
-#define XaceHook(args...) Success
 #define XaceHookIsSet(args...) 0
 #define XaceHookDispatch(args...) Success
 #define XaceHookPropertyAccess(args...) Success
 #define XaceHookSelectionAccess(args...) Success
 #define XaceCensorImage(args...) { ; }
 #else
-#define XaceHook(...) Success
 #define XaceHookIsSet(...) 0
 #define XaceHookDispatch(...) Success
 #define XaceHookPropertyAccess(...) Success

Xi/exevents.c

@@ -1880,7 +1880,7 @@ ProcessDeviceEvent(InternalEvent *ev, DeviceIntPtr device)
         int count;
 
         if (EventToCore(ev, &core, &count) == Success && count > 0) {
-            XaceHook(XACE_KEY_AVAIL, core, device, 0);
+            XaceHookKeyAvail(core, device, 0);
             free(core);
         }
     }