dix: add AllocGrab helper function

Not needed since the GrabRec is a self-contained struct but will be needed
for the xi2 input mask rework.
FreeGrab already exists, make it available to other callers.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Chase Douglas <chase.douglas@canonical.com>

dix/grabs.c

@@ -180,6 +180,14 @@ UngrabAllDevices(Bool kill_client)
     ErrorF("End list of ungrabbed devices\n");
 }
 
+GrabPtr
+AllocGrab(void)
+{
+    GrabPtr grab = calloc(1, sizeof(GrabRec));
+
+    return grab;
+}
+
 GrabPtr
 CreateGrab(
     int client,
@@ -196,7 +204,7 @@ CreateGrab(
 {
     GrabPtr grab;
 
-    grab = calloc(1, sizeof(GrabRec));
+    grab = AllocGrab();
     if (!grab)
 	return (GrabPtr)NULL;
     grab->resource = FakeClientID(client);
@@ -226,7 +234,7 @@ CreateGrab(
 
 }
 
-static void
+void
 FreeGrab(GrabPtr pGrab)
 {
     free(pGrab->modifiersDetail.pMask);

include/dixgrabs.h

@@ -31,6 +31,9 @@ struct _GrabParameters;
 extern void PrintDeviceGrabInfo(DeviceIntPtr dev);
 extern void UngrabAllDevices(Bool kill_client);
 
+extern GrabPtr AllocGrab(void);
+extern void FreeGrab(GrabPtr grab);
+
 extern GrabPtr CreateGrab(
 	int /* client */,
 	DeviceIntPtr /* device */,