Make heap walker accept callback

* alloc.c (GC_mercury_callback_reachable_object): Remove.
* include/gc.h (GC_mercury_callback_reachable_object): Likewise.
* include/private/gc_priv.h (GC_mercury_enumerate_reachable_objects):
Likewise.
* alloc.c (GC_finish_collection): Do not call
GC_mercury_enumerate_reachable_objects.
* include/gc_mark.h (GC_reachable_object_proc): New public typedef.
* include/gc_mark.h (GC_enumerate_reachable_objects_inner): New API
function declaration.
* reclaim.c (enumerate_reachable_s): New struct type.
* reclaim.c (GC_mercury_do_enumerate_reachable_objects): Rename to
GC_do_enumerate_reachable_objects; replace while() with for(); use 2nd
argument to pass client callback and custom data; call client callback
(passed via the argument) instead of
GC_mercury_callback_reachable_object; pass object size in bytes
instead of words to client callback.
* reclaim.c (GC_mercury_enumerate_reachable_objects): Rename to
GC_enumerate_reachable_objects_inner; decorate with GC_API/GC_CALL;
add 2 arguments (client callback and custom data); remove assertion
for GC_mercury_callback_reachable_object; add assertion for acquired
lock.
* tests/test.c: Include gc_mark.h unconditionally.
* tests/test.c (reachable_objs_counter,
reachable_objs_count_enumerator): New function.
* tests/test.c (check_heap_stats): New local variable "obj_count";
invoke GC_call_with_alloc_lock(reachable_objs_count_enumerator);
print final number of reachable objects.

3 files changed, 10 insertions, 5 deletions

diff --git a/include/gc.h b/include/gc.h
index e98431ca..d1423818 100644
--- a/include/gc.h
+++ b/include/gc.h
@@ -392,9 +392,6 @@ GC_API GC_ATTR_DEPRECATED unsigned long GC_time_limit;
 GC_API void GC_CALL GC_set_time_limit(unsigned long);
 GC_API unsigned long GC_CALL GC_get_time_limit(void);
 
-GC_API void (*GC_mercury_callback_reachable_object)(GC_word *, size_t);
-                /* This object on the heap is reachable. */
-
 /* Public procedures */
 
 /* Set whether the GC will allocate executable memory pages or not.     */
diff --git a/include/gc_mark.h b/include/gc_mark.h
index 28d2005a..7edb7f5e 100644
--- a/include/gc_mark.h
+++ b/include/gc_mark.h
@@ -289,6 +289,16 @@ typedef void (GC_CALLBACK * GC_push_other_roots_proc)(void);
 GC_API void GC_CALL GC_set_push_other_roots(GC_push_other_roots_proc);
 GC_API GC_push_other_roots_proc GC_CALL GC_get_push_other_roots(void);
 
+/* Walk the GC heap visiting all reachable objects.  Assume the caller  */
+/* holds the allocation lock.  Object base pointer, object size and     */
+/* client custom data are passed to the callback (holding the lock).    */
+typedef void (GC_CALLBACK *GC_reachable_object_proc)(void * /* obj */,
+                                                size_t /* bytes */,
+                                                void * /* client_data */);
+GC_API void GC_CALL GC_enumerate_reachable_objects_inner(
+                                GC_reachable_object_proc,
+                                void * /* client_data */) GC_ATTR_NONNULL(1);
+
 #ifdef __cplusplus
   } /* end of extern "C" */
 #endif
diff --git a/include/private/gc_priv.h b/include/private/gc_priv.h
index e369a7cc..f3f0718e 100644
--- a/include/private/gc_priv.h
+++ b/include/private/gc_priv.h
@@ -2082,8 +2082,6 @@ void GC_print_static_roots(void);
 
 extern word GC_fo_entries; /* should be visible in extra/MacOS.c */
 
-GC_INNER void GC_mercury_enumerate_reachable_objects(void);
-
 #ifdef KEEP_BACK_PTRS
    GC_INNER void GC_store_back_pointer(ptr_t source, ptr_t dest);
    GC_INNER void GC_marked_for_finalization(ptr_t dest);