tear off on longjmp

src/cont.c

@@ -164,9 +164,12 @@ native_stack_extend(pic_state *pic, struct pic_cont *cont)
 noreturn static void
 restore_cont(pic_state *pic, struct pic_cont *cont)
 {
+  void pic_vm_tear_off(pic_state *);
   char v;
   struct pic_cont *tmp = cont;
 
+  pic_vm_tear_off(pic);         /* tear off */
+
   if (&v < pic->native_stack_start) {
     if (&v > cont->stk_pos) native_stack_extend(pic, cont);
   }

src/error.c

@@ -91,11 +91,16 @@ error_new(pic_state *pic, short type, pic_str *msg, pic_value irrs)
 noreturn void
 pic_throw_error(pic_state *pic, struct pic_error *e)
 {
+  void pic_vm_tear_off(pic_state *);
+
+  pic_vm_tear_off(pic);         /* tear off */
+
   pic->err = e;
   if (! pic->jmp) {
     puts(pic_errmsg(pic));
     abort();
   }
+
   longjmp(*pic->jmp, 1);
 }
 

src/vm.c

@@ -503,12 +503,28 @@ vm_tear_off(pic_state *pic)
   assert(pic->ci->env != NULL);
 
   env = pic->ci->env;
+
+  if (env->regs == env->storage) {
+    return;                     /* is torn off */
+  }
   for (i = 0; i < env->regc; ++i) {
     env->storage[i] = env->regs[i];
   }
   env->regs = env->storage;
 }
 
+void
+pic_vm_tear_off(pic_state *pic)
+{
+  pic_callinfo *ci;
+
+  for (ci = pic->ci; ci > pic->cibase; ci--) {
+    if (pic->ci->env != NULL) {
+      vm_tear_off(pic);
+    }
+  }
+}
+
 pic_value
 pic_apply0(pic_state *pic, struct pic_proc *proc)
 {