diff --git a/ChangeLog b/ChangeLog
index 37a2b75022..c6cb78f5b5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,12 @@
-Wed Jul 23 17:51:18 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Wed Jul 23 18:03:31 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/dl/dl.c (rb_ary_to_ptr), ext/dl/ptr.c (rb_dlmem_delete):
+	  suppress warnings.
+
+	* ext/dl/ptr.c (rb_dlptr_inspect), ext/dl/sym.c (rb_dlsym_inspect):
+	  use %p conversion.
+
+	* ext/dl/sym.c (rb_dlsym_guardcall): prevent guard from optimization.
 
 	* ext/nkf/nkf-utf8/nkf.c (options): operators without any effect.
 
diff --git a/ext/dl/dl.c b/ext/dl/dl.c
index f65247be86..8a4643c7de 100644
--- a/ext/dl/dl.c
+++ b/ext/dl/dl.c
@@ -547,6 +547,8 @@ rb_ary_to_ptr(int argc, VALUE argv[], VALUE self)
   case 0:
     ptr = rb_ary2cary(0, self, &size);
     break;
+  default:
+    return Qnil;
   }
   if (ptr) {
       VALUE p = rb_dlptr_new(ptr, size, dlfree);
diff --git a/ext/dl/ptr.c b/ext/dl/ptr.c
index 01eb31da20..075259479d 100644
--- a/ext/dl/ptr.c
+++ b/ext/dl/ptr.c
@@ -18,8 +18,9 @@ static st_table* st_memory_table;
 static void
 rb_dlmem_delete(void *ptr)
 {
+  st_data_t data = (st_data_t)ptr;
   rb_secure(4);
-  st_delete(st_memory_table, (st_data_t*)&ptr, NULL);
+  st_delete(st_memory_table, &data, NULL);
 }
 
 static void
@@ -458,7 +459,7 @@ rb_dlptr_inspect(VALUE self)
   char str[1024];
 
   Data_Get_Struct(self, struct ptr_data, data);
-  snprintf(str, 1023, "#<%s:0x%lx ptr=0x%lx size=%ld free=0x%lx>",
+  snprintf(str, 1023, "#<%s:%p ptr=%p size=%ld free=0x%lx>",
 	   rb_class2name(CLASS_OF(self)), data, data->ptr, data->size,
 	   (long)data->free);
   return rb_str_new2(str);
diff --git a/ext/dl/sym.c b/ext/dl/sym.c
index 933fb7f4f0..8c7c0ecf60 100644
--- a/ext/dl/sym.c
+++ b/ext/dl/sym.c
@@ -268,7 +268,7 @@ rb_dlsym_inspect(VALUE self)
   str_size = RSTRING(proto)->len + 100;
   str = dlmalloc(str_size);
   snprintf(str, str_size - 1,
-          "#<DL::Symbol:0x%lx func=0x%lx '%s'>",
+          "#<DL::Symbol:%p func=%p '%s'>",
 	   sym, sym->func, RSTRING(proto)->ptr);
   val = rb_tainted_str_new2(str);
   dlfree(str);
@@ -430,6 +430,7 @@ rb_dlsym_guardcall(char type, ANY_TYPE *ret, long *stack, void *func)
   default:
     return 0;
   }
+  (void)guard;
   return 1;
 }
 # ifdef __MSVC_RUNTIME_CHECKS