* alloc.c (DEADP): New macro, for porting to GNU/Hurd (Bug#9926).

This is also needed for porting to any host where GC_MARK_STACK is
not GC_MAKE_GCPROS_NOOPS.
(which_symbols): Use it.

src/ChangeLog

+2011-11-07  Paul Eggert  <eggert@cs.ucla.edu>
+
+	* alloc.c (DEADP): New macro, for porting to GNU/Hurd (Bug#9926).
+	This is also needed for porting to any host where GC_MARK_STACK is
+	not GC_MAKE_GCPROS_NOOPS.
+	(which_symbols): Use it.
+
 2011-11-07  Kenichi Handa  <handa@m17n.org>
 
 	* coding.c (coding_set_destination): Check coding->src_pos only

src/alloc.c

@@ -315,6 +315,7 @@ static POINTER_TYPE *lisp_malloc (size_t, enum mem_type);
    on free lists recognizable in O(1).  */
 
 static Lisp_Object Vdead;
+#define DEADP(x) EQ (x, Vdead)
 
 #ifdef GC_MALLOC_CHECK
 
@@ -411,6 +412,10 @@ static void check_gcpros (void);
 
 #endif /* GC_MARK_STACK || GC_MALLOC_CHECK */
 
+#ifndef DEADP
+# define DEADP(x) 0
+#endif
+
 /* Recording what needs to be marked for gc.  */
 
 struct gcpro *gcprolist;
@@ -6261,7 +6266,7 @@ which_symbols (Lisp_Object obj, EMACS_INT find_max)
    int gc_count = inhibit_garbage_collection ();
    Lisp_Object found = Qnil;
 
-   if (!EQ (obj, Vdead))
+   if (! DEADP (obj))
      {
        for (sblk = symbol_block; sblk; sblk = sblk->next)
 	 {