4 files changed, 25 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index 28131396..217d892b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
 2014-08-25  Kaz Kylheku  <kaz@kylheku.com>
 
+	* gc.c (top): Renamed to gc_prot_top, turned extern.
+	(prot1, rel1, mark): Follow rename.
+
+	* gc.h (gc_prot_top): Declared.
+
+	* signal.h (extended_jmp_buf): New member, gc_pt.
+	(extended_setjmp): Save and restore gc_prot_top.
+
+2014-08-25  Kaz Kylheku  <kaz@kylheku.com>
+
 	GC correctness fixes: make sure we pin down objects for which we borrow
 	low level C pointers, while we execute code that can cons memory.
 
diff --git a/gc.c b/gc.c
index 5fdbdf4b..9d5b61b9 100644
--- a/gc.c
+++ b/gc.c
@@ -69,7 +69,7 @@ static val *gc_stack_bottom;
 
 static val *prot_stack[PROT_STACK_SIZE];
 static val **prot_stack_limit = prot_stack + PROT_STACK_SIZE;
-static val **top = prot_stack;
+val **gc_prot_top = prot_stack;
 
 static val free_list, *free_tail = &free_list;
 static heap_t *heap_list;
@@ -95,16 +95,16 @@ val break_obj;
 
 val prot1(val *loc)
 {
-  assert (top < prot_stack_limit);
+  assert (gc_prot_top < prot_stack_limit);
   assert (loc != 0);
-  *top++ = loc;
+  *gc_prot_top++ = loc;
   return nil; /* for use in macros */
 }
 
 void rel1(val *loc)
 {
   /* protect and release calls must nest. */
-  if (*--top != loc)
+  if (*--gc_prot_top != loc)
     abort();
 }
 
@@ -401,7 +401,7 @@ static void mark(mach_context_t *pmc, val *gc_stack_top)
   /*
    * First, scan the officially registered locations.
    */
-  for (rootloc = prot_stack; rootloc != top; rootloc++)
+  for (rootloc = prot_stack; rootloc != gc_prot_top; rootloc++)
     mark_obj(**rootloc);
 
 #if CONFIG_GEN_GC
diff --git a/gc.h b/gc.h
index aa79f556..99e0938d 100644
--- a/gc.h
+++ b/gc.h
@@ -44,6 +44,7 @@ void unmark(void);
 void gc_hint_func(val *);
 
 extern int gc_enabled;
+extern val **gc_prot_top;
 
 #if EXTRA_DEBUGGING
 val break_obj;
diff --git a/signal.h b/signal.h
index 4fe9d823..0bbff153 100644
--- a/signal.h
+++ b/signal.h
@@ -63,6 +63,7 @@ typedef struct {
   sigset_t blocked;
   val de;
   int gc;
+  val **gc_pt;
   int rv;
 } extended_jmp_buf;
 
@@ -70,13 +71,16 @@ typedef struct {
   (setjmp((EJB).jb)                             \
    ? (async_sig_enabled = (EJB).se,             \
       dyn_env = (EJB).de,                       \
-      gc_enabled = ((EJB).gc),                  \
+      gc_enabled = (EJB).gc,                    \
+      gc_prot_top = (EJB).gc_pt,                \
       sig_mask(SIG_SETMASK, &(EJB).blocked, 0), \
       (EJB).rv)                                 \
    : ((EJB).se = async_sig_enabled,             \
       (EJB).de = dyn_env,                       \
       (EJB).gc = gc_enabled,                    \
-      (EJB).blocked = sig_blocked_cache, 0))
+      (EJB).gc_pt = gc_prot_top,                \
+      (EJB).blocked = sig_blocked_cache,        \
+      0))
 
 #define extended_longjmp(EJB, ARG)              \
   ((EJB).rv = (ARG), longjmp((EJB).jb, 1))
@@ -96,6 +100,7 @@ typedef struct {
   jmp_buf jb;
   val de;
   int gc;
+  val **gc_pt;
   int rv;
 } extended_jmp_buf;
 
@@ -103,9 +108,11 @@ typedef struct {
   (setjmp((EJB).jb)                             \
    ? (dyn_env = (EJB).de,                       \
       gc_enabled = ((EJB).gc),                  \
+      gc_prot_top = (EJB).gc_pt,                \
       (EJB).rv)                                 \
    : ((EJB).de = dyn_env,                       \
       (EJB).gc = gc_enabled,                    \
+      (EJB).gc_pt = gc_prot_top,                \
       0))
 
 #define extended_longjmp(EJB, ARG)              \