Make comparisons to the lowest heap boundary strict

* alloc.c (GC_expand_hp_inner): Subtract sizeof(word) from new_limit
(for the case when comparing to GC_least_plausible_heap_addr).
* backgraph.c [MAKE_BACK_GRAPH] (add_back_edges): Compare current to
GC_least_real_heap_addr and GC_greatest_real_heap_addr (instead of
GC_least_plausible_heap_addr and GC_greatest_plausible_heap_addr).
* malloc.c [GC_ASSERTIONS] (GC_malloc_kind_global): Likewise.
* include/gc/gc_mark.h (GC_MARK_AND_PUSH): Replace greater-or-equal to
strictly greater when comparing to GC_least_plausible_heap_addr.
* include/private/gc_pmark.h (GC_PUSH_ONE_STACK, GC_PUSH_ONE_HEAP):
Likewise.
* include/private/gc_priv.h [MAKE_BACK_GRAPH] (SET_REAL_HEAP_BOUNDS,
GC_least_real_heap_addr, GC_greatest_real_heap_addr): Define.
* mark.c (GC_mark_from, GC_push_all): Add dummy "| GC_DS_LENGTH" when
storing length to mse_descr.w.
* mark.c (GC_mark_from): Replace greater-or-equal to strictly greater
when comparing to least_ha variable.
* typd_mlc.c (GC_typed_mark_proc): Likewise.
* mark.c [GC_DS_TAGS>ALIGNMENT-1] (GC_push_all): Simplify code to
round up length.

1 files changed, 3 insertions, 5 deletions

diff --git a/malloc.c b/malloc.c
index d921daeb..24aace59 100644
--- a/malloc.c
+++ b/malloc.c
@@ -324,11 +324,9 @@ GC_API GC_ATTR_MALLOC void * GC_CALL GC_malloc_kind_global(size_t lb, int k)
             if (k == PTRFREE) {
                 *opp = obj_link(op);
             } else {
-                GC_ASSERT(0 == obj_link(op)
-                          || ((word)obj_link(op)
-                                < (word)GC_greatest_plausible_heap_addr
-                              && (word)obj_link(op)
-                                >= (word)GC_least_plausible_heap_addr));
+                GC_ASSERT(NULL == obj_link(op)
+                          || ((word)obj_link(op) < GC_greatest_real_heap_addr
+                             && (word)obj_link(op) > GC_least_real_heap_addr));
                 *opp = obj_link(op);
                 obj_link(op) = 0;
             }