Do not call GC_push_conditional unless PROC_VDB

As of now, only PROC_VDB can determine whether a static root page
is dirty.  Thus, GC_push_all could be used (instead of
GC_push_conditional) in mark_rts.c for other VDB implementations.

* include/private/gcconfig.h [!PROC_VDB] (NO_VDB_FOR_STATIC_ROOTS): New
macro; add comment.
* mark_rts.c (GC_PUSH_CONDITIONAL_STATIC): New internal macro; move
comment from GC_PUSH_CONDITIONAL; mark "all" argument as used.
* mark_rts.c (GC_PUSH_CONDITIONAL): Use GC_PUSH_CONDITIONAL_STATIC();
do not test GC_DISABLE_INCREMENTAL directly.
* mark_rts.c (GC_push_conditional_with_exclusions): Remove
GC_ATTR_UNUSED for "all" argument.

include/private/gcconfig.h

@@ -3256,6 +3256,11 @@ EXTERN_C_BEGIN
 # define DEFAULT_VDB
 #endif
 
+#if !defined(PROC_VDB) && !defined(NO_VDB_FOR_STATIC_ROOTS)
+  /* Cannot determine whether a static root page is dirty?      */
+# define NO_VDB_FOR_STATIC_ROOTS
+#endif
+
 #if ((defined(UNIX_LIKE) && (defined(DARWIN) || defined(HAIKU) \
                              || defined(HURD) || defined(OPENBSD) \
                              || defined(ARM32) \

mark_rts.c

@@ -615,22 +615,27 @@ GC_API void GC_CALL GC_exclude_static_roots(void *b, void *e)
     UNLOCK();
 }
 
+#ifdef NO_VDB_FOR_STATIC_ROOTS
+# define GC_PUSH_CONDITIONAL_STATIC(b, t, all) \
+                ((void)(all), GC_push_all(b, t))
+#else
+# define GC_PUSH_CONDITIONAL_STATIC(b, t, all) GC_push_conditional(b, t, all)
+                        /* Do either of GC_push_all or GC_push_selected */
+                        /* depending on the third arg.                  */
+#endif
+
 #if defined(WRAP_MARK_SOME) && defined(PARALLEL_MARK)
 # define GC_PUSH_CONDITIONAL(b, t, all) \
                 (GC_parallel \
                     ? GC_push_conditional_eager(b, t, all) \
-                    : GC_push_conditional(b, t, all))
-#elif defined(GC_DISABLE_INCREMENTAL)
-# define GC_PUSH_CONDITIONAL(b, t, all) GC_push_all(b, t)
+                    : GC_PUSH_CONDITIONAL_STATIC(b, t, all))
 #else
-# define GC_PUSH_CONDITIONAL(b, t, all) GC_push_conditional(b, t, all)
-                        /* Do either of GC_push_all or GC_push_selected */
-                        /* depending on the third arg.                  */
+# define GC_PUSH_CONDITIONAL(b, t, all) GC_PUSH_CONDITIONAL_STATIC(b, t, all)
 #endif
 
 /* Invoke push_conditional on ranges that are not excluded. */
 STATIC void GC_push_conditional_with_exclusions(ptr_t bottom, ptr_t top,
-                                                GC_bool all GC_ATTR_UNUSED)
+                                                GC_bool all)
 {
     while ((word)bottom < (word)top) {
         struct exclusion *next = GC_next_exclusion(bottom);