diff -r 86adfe1982ef -r c50d9ff68898 typing/typeclass.ml
--- a/typing/typeclass.ml	Fri Jun 15 23:13:01 2012 +0900
+++ b/typing/typeclass.ml	Mon Jun 18 03:12:40 2012 +0900
@@ -344,11 +344,11 @@
   (cty, cty')
 
 let mkpat d = { ppat_desc = d; ppat_loc = Location.none }
-let make_method cl_num expr =
+let make_method self_loc cl_num expr =
   { pexp_desc =
       Pexp_function ("", None,
                      [mkpat (Ppat_alias (mkpat(Ppat_var (mknoloc "self-*")),
-                                         mknoloc ("self-" ^ cl_num))),
+                                         mkloc ("self-" ^ cl_num) self_loc)),
                       expr]);
     pexp_loc = expr.pexp_loc }
 
@@ -492,7 +492,7 @@
 
 (*******************************)
 
-let rec class_field cl_num self_type meths vars
+let rec class_field self_loc cl_num self_type meths vars
     (val_env, met_env, par_env, fields, concr_meths, warn_vals, inher)
   cf =
   let loc = cf.pcf_loc in
@@ -630,7 +630,7 @@
       with Ctype.Unify trace ->
         raise(Error(loc, Field_type_mismatch ("method", lab.txt, trace)))
       end;
-      let meth_expr = make_method cl_num expr in
+      let meth_expr = make_method self_loc cl_num expr in
       (* backup variables for Pexp_override *)
       let vars_local = !vars in
 
@@ -657,7 +657,7 @@
         concr_meths, warn_vals, inher)
 
   | Pcf_init expr ->
-      let expr = make_method cl_num expr in
+      let expr = make_method self_loc cl_num expr in
       let vars_local = !vars in
       let field =
         lazy begin
@@ -678,6 +678,9 @@
   (* Environment for substructures *)
   let par_env = met_env in
 
+  (* Location of self. Used for locations of self arguments *)
+  let self_loc = spat.ppat_loc in
+
   (* Self type, with a dummy method preventing it from being closed/escaped. *)
   let self_type = Ctype.newvar () in
   Ctype.unify val_env
@@ -718,7 +721,7 @@
 
   (* Typing of class fields *)
   let (_, _, _, fields, concr_meths, _, inher) =
-    List.fold_left (class_field cl_num self_type meths vars)
+    List.fold_left (class_field self_loc cl_num self_type meths vars)
       (val_env, meth_env, par_env, [], Concr.empty, Concr.empty, [])
       str
   in