Fix SIGSEGV in GC_is_marked when gc_cleanup is used in leak-finding mode

Issue #162 (bdwgc).

Now finalizers and disappearing links registration is a no-op in case
of the leak-finding mode.

*  finalize.c (GC_register_disappearing_link_inner): Do nothing (return
GC_UNIMPLEMENTED) if GC_find_leak.
* finalize.c (GC_register_finalizer_inner): Do nothing if GC_find_leak.
* include/gc.h (GC_find_leak): More verbose comment.
* include/gc.h (GC_debug_register_finalizer,
GC_general_register_disappearing_link): Document the case of
GC_find_leak.

1 files changed, 2 insertions, 0 deletions

diff --git a/finalize.c b/finalize.c
index 4b652790..bd297a9c 100644
--- a/finalize.c
+++ b/finalize.c
@@ -152,6 +152,7 @@ STATIC int GC_register_disappearing_link_inner(
     struct disappearing_link * new_dl;
     DCL_LOCK_STATE;
 
+    if (EXPECT(GC_find_leak, FALSE)) return GC_UNIMPLEMENTED;
     LOCK();
     GC_ASSERT(obj != NULL && GC_base_C(obj) == obj);
     if (dl_hashtbl -> log_size == -1
@@ -647,6 +648,7 @@ STATIC void GC_register_finalizer_inner(void * obj,
     hdr *hhdr = NULL; /* initialized to prevent warning. */
     DCL_LOCK_STATE;
 
+    if (EXPECT(GC_find_leak, FALSE)) return;
     LOCK();
     if (log_fo_table_size == -1
         || GC_fo_entries > ((word)1 << log_fo_table_size)) {