From eb9a6467cb0860abf57f773a82da526aedc9802a Mon Sep 17 00:00:00 2001
From: =?utf8?q?Kim=20Nguy=E1=BB=85n?= <kn@lri.fr>
Date: Sat, 13 Oct 2012 14:54:02 +0200
Subject: [PATCH] Add runtime assertion to check that values passed to
 Obj_val() are indeed custom blocks.

---
 myocamlbuild.ml     | 2 +-
 src/common_stub.hpp | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/myocamlbuild.ml b/myocamlbuild.ml
index 7a792d1..6f27e4e 100644
--- a/myocamlbuild.ml
+++ b/myocamlbuild.ml
@@ -127,7 +127,7 @@ let () = dispatch begin
 	compile_flags @= [A "-noassert"];
 	pp_macro_options @= [ A "-unsafe" ];
 	native_compile_flags @= [ A "-inline"; A ocaml_inline ];
-	cxx_flags @= [ A "-O3" ]
+	cxx_flags @= [ A "-O3"; A "-DNDEBUG" ]
       end;
 
       let dir_path = Pathname.pwd / src_path in
diff --git a/src/common_stub.hpp b/src/common_stub.hpp
index 3e874b7..45aa0ca 100644
--- a/src/common_stub.hpp
+++ b/src/common_stub.hpp
@@ -14,6 +14,7 @@ extern "C" {
 }
 #include <typeinfo>
 #include <cstdio>
+#include <cassert>
 
 #define NoAlloc
 
@@ -26,6 +27,7 @@ value alloc_custom_(char* name);
 
 template <class X> X& Obj_val(value v)
 {
+  assert(Tag_val(v) == Custom_tag);
   return * (X*) Data_custom_val(v);
 }
 
-- 
2.17.1