diff --git a/compiler/global/idents.ml b/compiler/global/idents.ml
index dffcec5..9fdddab 100644
--- a/compiler/global/idents.ml
+++ b/compiler/global/idents.ml
@@ -9,6 +9,11 @@
 
 (* naming and local environment *)
 
+(* TODO AG : preprocessing pour avoir un release efficace :
+IFDEF RELEASE type iden = int
+ELSE *)
+
+
 
 type ident = {
   num : int;        (* a unique index *)
@@ -21,16 +26,15 @@ type var_ident = ident
 let num = ref 0
 
 let ident_compare id1 id2 = compare id1.num id2.num
-let sourcename id = id.source
+
+(* used only for debuging *)
 let name id =
   if id.is_generated then
     id.source ^ "_" ^ (string_of_int id.num)
   else
     id.source
 
-let set_sourcename id v =
-  { id with source = v }
-
+(* used only for debuging *)
 let fprint_t ff id = Format.fprintf ff "%s" (name id)
 
 module M = struct
@@ -77,13 +81,21 @@ end
 module S = Set.Make (struct type t = string
                             let compare = Pervasives.compare end)
 
+
+(** Module used to generate unique string (inside a node) per ident.
+    /!\ Any pass generating a name must call [enter_node] and use gen_fresh *)
 module UniqueNames =
 struct
-  let used_names = ref S.empty
-  let env = ref Env.empty
+  open Names
+  let used_names = ref (ref S.empty) (** Used strings in the current node *)
+  let env = ref Env.empty (** Map idents to their string *)
+  let (node_env : S.t ref QualEnv.t ref) = ref QualEnv.empty
 
-  let new_function () =
-    used_names := S.empty
+  (** This function should be called every time we enter a node *)
+  let enter_node n =
+    (if not (QualEnv.mem n !node_env)
+    then node_env := QualEnv.add n (ref S.empty) !node_env);
+    used_names := QualEnv.find n !node_env
 
   (** @return a unique string for each identifier. Idents corresponding
       to variables defined in the source file have the same name unless
@@ -91,33 +103,34 @@ struct
   let assign_name n =
     let fresh s =
       num := !num + 1;
-      s ^ "_" ^ (string_of_int !num)
-    in
+      s ^ "_" ^ (string_of_int !num) in
     let rec fresh_string base =
-      let base = fresh base in
-        if S.mem base !used_names then fresh_string base else base
-    in
-      if not (Env.mem n !env) then
-        let s = name n in
-        let s = if S.mem s !used_names then fresh_string s else s in
-          used_names := S.add s !used_names;
-          env := Env.add n s !env
+      let fs = fresh base in
+      if S.mem fs !(!used_names) then fresh_string base else fs in
+    if not (Env.mem n !env) then
+      (let s = n.source in
+       let s = if S.mem s !(!used_names) then fresh_string s else s in
+       !used_names := S.add s !(!used_names);
+       env := Env.add n s !env)
 
   let name id =
     Env.find id !env
 end
 
-let fresh s =
+let gen_fresh pass_name kind_to_string kind =
+  let s = "__" ^ pass_name ^ "_" ^ (kind_to_string kind) in
   num := !num + 1;
   let id = { num = !num; source = s; is_generated = true } in
     UniqueNames.assign_name id; id
 
+let gen_var pass_name name = gen_fresh pass_name (fun () -> name) ()
+
 let ident_of_name s =
   num := !num + 1;
   let id = { num = !num; source = s; is_generated = false } in
     UniqueNames.assign_name id; id
 
 let name id = UniqueNames.name id
-let new_function () = UniqueNames.new_function ()
+let enter_node n = UniqueNames.enter_node n
 
 let print_ident ff id = Format.fprintf ff "%s" (name id)
diff --git a/compiler/global/idents.mli b/compiler/global/idents.mli
index fb6e88b..ee1ab96 100644
--- a/compiler/global/idents.mli
+++ b/compiler/global/idents.mli
@@ -1,8 +1,9 @@
 
+open Names
+
 (** This modules manages unique identifiers,
-  [fresh] generates an identifier from a name
-  [name] returns a unique name from an identifier. *)
-
+  [gen_fresh] generates an identifier
+  [name] returns a unique name (inside its node) from an identifier. *)
 
 (** The (abstract) type of identifiers*)
 type ident
@@ -13,21 +14,21 @@ type var_ident = ident
 (** Comparision on idents with the same properties as [Pervasives.compare] *)
 val ident_compare : ident -> ident -> int
 
-(** Get the source name from an identifier*)
-val sourcename : ident -> string
 (** Get the full name of an identifier (it is guaranteed to be unique) *)
 val name : ident -> string
-(** [set_sourcename id v] returns id with its source name changed to v. *)
-val set_sourcename : ident -> string -> ident
 
-(** [fresh n] returns a fresh identifier with source name n *)
-val fresh : string -> ident
+(** [gen_fresh pass_name kind_to_string kind]
+    generate a fresh ident with a sweet [name].
+    It should be used to define a [fresh] function specific to a pass. *)
+val gen_fresh : string -> ('a -> string) -> 'a -> ident
+val gen_var : string -> string -> ident
+
 (** [ident_of_name n] returns an identifier corresponding
   to a _source_ variable (do not use it for generated variables). *)
 val ident_of_name : string -> ident
-(** Resets the sets that makes sure that idents are mapped to unique
-    identifiers. Should be called when scoping a new function. *)
-val new_function : unit -> unit
+
+(** /!\ This function should be called every time we enter a node *)
+val enter_node : Names.qualname -> unit
 
 (** Maps taking an identifier as a key. *)
 module Env :
diff --git a/compiler/global/modules.ml b/compiler/global/modules.ml
index 6fce969..26762d6 100644
--- a/compiler/global/modules.ml
+++ b/compiler/global/modules.ml
@@ -225,28 +225,34 @@ let current_qual n = { qual = g_env.current_mod; name = n }
 
 (** { 3 Fresh functions return a fresh qualname for the current module } *)
 
-let rec fresh_value name =
-  let q = current_qual ("__" ^ name ^ "_" ^ Misc.gen_symbol()) in
+let rec fresh_value pass_name name =
+  let q = current_qual ("__"^ pass_name ^"_"^ name) in
   if QualEnv.mem q g_env.values
-  then fresh_value name
+  then fresh_value pass_name (name ^"_"^ Misc.gen_symbol())
   else q
 
-let rec fresh_type name =
-  let q = current_qual ("__" ^ name ^ "_" ^ Misc.gen_symbol()) in
+let rec fresh_value_in pass_name name qualifier =
+  let q = { qual = qualifier; name = "__"^ pass_name ^"_"^ name } in
+  if QualEnv.mem q g_env.values
+  then fresh_value_in pass_name (name ^"_"^ Misc.gen_symbol()) qualifier
+  else q
+
+let rec fresh_type pass_name name =
+  let q = current_qual ("__"^ pass_name ^"_"^ name) in
   if QualEnv.mem q g_env.types
-  then fresh_type name
+  then fresh_type pass_name (name ^"_"^ Misc.gen_symbol())
   else q
 
-let rec fresh_const name =
-  let q = current_qual ("__" ^ name ^ "_" ^ Misc.gen_symbol()) in
+let rec fresh_const pass_name name =
+  let q = current_qual ("__"^ pass_name ^"_"^ name) in
   if QualEnv.mem q g_env.consts
-  then fresh_const name
+  then fresh_const pass_name (name ^"_"^ Misc.gen_symbol())
   else q
 
-let rec fresh_constr name =
-  let q = current_qual ("__" ^ name ^ "_" ^ Misc.gen_symbol()) in
+let rec fresh_constr pass_name name =
+  let q = current_qual ("__"^ pass_name ^"_"^ name) in
   if QualEnv.mem q g_env.constrs
-  then fresh_constr name
+  then fresh_constr pass_name (name ^"_"^ Misc.gen_symbol())
   else q
 
 
diff --git a/compiler/global/names.ml b/compiler/global/names.ml
index 273f2e3..2fe3877 100644
--- a/compiler/global/names.ml
+++ b/compiler/global/names.ml
@@ -75,3 +75,7 @@ let print_raw_qualname ff {qual = q; name = n} =
 let opname qn = match qn with
   | { qual = "Pervasives"; name = m; } -> m
   | { qual = qual; name = n; } -> qual ^ "." ^ n
+
+(** Use a printer to generate a string compatible with a name *)
+let print_pp_to_name p x =
+  Misc.sanitize_string (Misc.print_pp_to_string p x)
diff --git a/compiler/heptagon/analysis/statefull.ml b/compiler/heptagon/analysis/statefull.ml
index f15e84b..a862492 100644
--- a/compiler/heptagon/analysis/statefull.ml
+++ b/compiler/heptagon/analysis/statefull.ml
@@ -67,6 +67,7 @@ let present_handler funs acc ph =
     { ph with p_cond = p_cond; p_block = p_block }, acc
 
 let node_dec funs _ n =
+  Idents.enter_node n.n_name;
   let n, statefull = Hept_mapfold.node_dec funs false n in
     if statefull & not (n.n_statefull) then
       message n.n_loc Eshould_be_a_node;
diff --git a/compiler/heptagon/analysis/typing.ml b/compiler/heptagon/analysis/typing.ml
index f01c393..64c5bd7 100644
--- a/compiler/heptagon/analysis/typing.ml
+++ b/compiler/heptagon/analysis/typing.ml
@@ -231,7 +231,7 @@ let typ_of_name h x =
   try
     let { ty = ty } = Env.find x h in ty
   with
-      Not_found -> error (Eundefined(sourcename x))
+      Not_found -> error (Eundefined(name x))
 
 let desc_of_ty = function
   | Tid n when n = pbool  -> Tenum [ptrue; pfalse]
@@ -290,7 +290,7 @@ let diff_const defined_names local_names =
     the difference *)
 let included_env s1 s2 =
   Env.iter
-    (fun elt _ -> if not (Env.mem elt s2) then error (Emissing(sourcename elt)))
+    (fun elt _ -> if not (Env.mem elt s2) then error (Emissing(name elt)))
     s1
 
 let diff_env defined_names local_names =
@@ -321,7 +321,7 @@ let all_last h env =
   Env.iter
     (fun elt _ ->
        if not (Env.find elt h).last
-       then error (Elast_undefined(sourcename elt)))
+       then error (Elast_undefined(name elt)))
     env
 
 let last = function | Var -> false | Last _ -> true
@@ -977,7 +977,7 @@ and build const_env h dec =
         | Var | Last None -> vd.v_last in
 
       if Env.mem vd.v_ident h then
-        error (Ealready_defined(sourcename vd.v_ident));
+        error (Ealready_defined(name vd.v_ident));
 
       let acc_defined = Env.add vd.v_ident ty acc_defined in
       let h = Env.add vd.v_ident { ty = ty; last = last vd.v_last } h in
@@ -994,7 +994,7 @@ let typing_contract const_env h contract =
     | Some ({ c_block = b;
               c_assume = e_a;
               c_enforce = e_g;
-							c_controllables = c }) ->
+              c_controllables = c }) ->
         let typed_b, defined_names, _ = typing_block const_env h b in
           (* check that the equations do not define other unexpected names *)
           included_env defined_names Env.empty;
@@ -1005,11 +1005,11 @@ let typing_contract const_env h contract =
         let typed_e_g = expect const_env h (Tid Initial.pbool) e_g in
 
         let typed_c, (c_names, h) = build const_env h c in
-				
+
         Some { c_block = typed_b;
                c_assume = typed_e_a;
                c_enforce = typed_e_g;
-							 c_controllables = typed_c }, h
+               c_controllables = typed_c }, h
 
 let solve loc cl =
   try
diff --git a/compiler/heptagon/hept_mapfold.ml b/compiler/heptagon/hept_mapfold.ml
index d2a5484..3d730ea 100644
--- a/compiler/heptagon/hept_mapfold.ml
+++ b/compiler/heptagon/hept_mapfold.ml
@@ -257,20 +257,22 @@ and contract funs acc c =
   let c_assume, acc = exp_it funs acc c.c_assume in
   let c_enforce, acc = exp_it funs acc c.c_enforce in
   let c_block, acc = block_it funs acc c.c_block in
-	let c_controllables, acc = mapfold (var_dec_it funs) acc c.c_controllables in
+  let c_controllables, acc = mapfold (var_dec_it funs) acc c.c_controllables in
   { c with
     c_assume = c_assume;
-		c_enforce = c_enforce;
-		c_block = c_block;
-		c_controllables = c_controllables },
-	acc
+    c_enforce = c_enforce;
+    c_block = c_block;
+    c_controllables = c_controllables },
+  acc
 
 and param_it funs acc vd = funs.param funs acc vd
 and param funs acc vd =
   let v_last, acc = last_it funs acc vd.v_last in
   { vd with v_last = v_last }, acc
 
-and node_dec_it funs acc nd = funs.node_dec funs acc nd
+and node_dec_it funs acc nd =
+  Idents.enter_node nd.n_name;
+  funs.node_dec funs acc nd
 and node_dec funs acc nd =
   let n_input, acc = mapfold (var_dec_it funs) acc nd.n_input in
   let n_output, acc = mapfold (var_dec_it funs) acc nd.n_output in
diff --git a/compiler/heptagon/parsing/hept_parser.mly b/compiler/heptagon/parsing/hept_parser.mly
index 52d5a44..7226a64 100644
--- a/compiler/heptagon/parsing/hept_parser.mly
+++ b/compiler/heptagon/parsing/hept_parser.mly
@@ -224,7 +224,7 @@ contract:
       { Some{ c_block = b;
               c_assume = $4;
               c_enforce = $5;
-	      c_controllables = $6 } }
+        c_controllables = $6 } }
 ;
 
 opt_assume:
@@ -445,8 +445,8 @@ _exp:
       { mk_op_call $2 [$1; $3] }
   | exp INFIX2 exp
       { mk_op_call $2 [$1; $3] }
-  | e=exp WHEN c=constructor_or_bool LPAREN n=IDENT RPAREN
-      { Ewhen (e, c, n) }
+  | e=exp WHEN c=constructor_or_bool LPAREN ce=IDENT RPAREN
+      { Ewhen (e, c, ce) }
   | MERGE n=IDENT hs=merge_handlers
       { Emerge (n, hs) }
   | exp INFIX1 exp
diff --git a/compiler/heptagon/parsing/hept_scoping.ml b/compiler/heptagon/parsing/hept_scoping.ml
index 71dee7d..cadd4f9 100644
--- a/compiler/heptagon/parsing/hept_scoping.ml
+++ b/compiler/heptagon/parsing/hept_scoping.ml
@@ -369,7 +369,7 @@ let translate_contract env ct =
   let b, _ = translate_block env ct.c_block in
   { Heptagon.c_assume = translate_exp env ct.c_assume;
     Heptagon.c_enforce = translate_exp env ct.c_enforce;
-		Heptagon.c_controllables = translate_vd_list env ct.c_controllables;
+    Heptagon.c_controllables = translate_vd_list env ct.c_controllables;
     Heptagon.c_block = b }
 
 let params_of_var_decs =
@@ -383,7 +383,8 @@ let args_of_var_decs =
                         (translate_type vd.v_loc vd.v_type))
 
 let translate_node node =
-  Idents.new_function ();
+  let n = current_qual node.n_name in
+  Idents.enter_node n;
   (* Inputs and outputs define the initial local env *)
   let env0 = Rename.append Rename.empty (node.n_input @ node.n_output) in
   let params = params_of_var_decs node.n_params in
@@ -393,7 +394,6 @@ let translate_node node =
   let contract =
     Misc.optional (translate_contract env) node.n_contract in
   (* the env of the block is used in the contract translation *)
-  let n = current_qual node.n_name in
   (* add the node signature to the environment *)
   let i = args_of_var_decs node.n_input in
   let o = args_of_var_decs node.n_output in
diff --git a/compiler/heptagon/transformations/automata.ml b/compiler/heptagon/transformations/automata.ml
index 98e45d1..9bd1a00 100644
--- a/compiler/heptagon/transformations/automata.ml
+++ b/compiler/heptagon/transformations/automata.ml
@@ -17,6 +17,10 @@ open Hept_mapfold
 open Initial
 open Modules
 
+type var = S | NS | R | NR | PNR
+let fresh = Idents.gen_fresh "automata"
+  (function S -> "s" | NS -> "ns" | R -> "r" | NR -> "nr" | PNR -> "pnr")
+
 let mk_var_exp n ty =
   mk_exp (Evar n) ty
 
@@ -46,7 +50,7 @@ let state_type_dec_list = ref []
 
 (* create and add to the env the constructors corresponding to a name state *)
 let intro_state_constr type_name state state_env =
-  let c = Modules.fresh_constr state in
+  let c = Modules.fresh_constr "automata" state in
   Modules.add_constrs c type_name; NamesEnv.add state c state_env
 
 (* create and add the the global env and to state_type_dec_list
@@ -68,7 +72,7 @@ let no_strong_transition state_handlers =
 
 
 let translate_automaton v eq_list handlers =
-  let type_name = Modules.fresh_type ("states") in
+  let type_name = Modules.fresh_type "automata" "states" in
   (* the state env associate a name to a qualified constructor *)
   let state_env =
     List.fold_left
@@ -80,11 +84,11 @@ let translate_automaton v eq_list handlers =
   (* The initial state constructor *)
   let initial = (NamesEnv.find (List.hd handlers).s_state state_env) in
 
-  let statename = Idents.fresh "s" in
-  let next_statename = Idents.fresh "ns" in
-  let resetname = Idents.fresh "r" in
-  let next_resetname = Idents.fresh "nr" in
-  let pre_next_resetname = Idents.fresh "pnr" in
+  let statename = fresh S in
+  let next_statename = fresh NS in
+  let resetname = fresh R in
+  let next_resetname = fresh NR in
+  let pre_next_resetname = fresh PNR in
 
   let name n = NamesEnv.find n state_env in
   let state n =
diff --git a/compiler/heptagon/transformations/inline.ml b/compiler/heptagon/transformations/inline.ml
index 9fe8e76..972e9e5 100644
--- a/compiler/heptagon/transformations/inline.ml
+++ b/compiler/heptagon/transformations/inline.ml
@@ -105,6 +105,7 @@ let block funs (env, newvars, newequs) blk =
    (env, [], []))
 
 let node_dec funs (env, newvars, newequs) nd =
+  Idents.enter_node nd.n_name;
   let nd, (env, newvars, newequs) =
     Hept_mapfold.node_dec funs (env, newvars, newequs) nd in
   ({ nd with n_block =
diff --git a/compiler/heptagon/transformations/last.ml b/compiler/heptagon/transformations/last.ml
index f0aa6bd..cf3420b 100644
--- a/compiler/heptagon/transformations/last.ml
+++ b/compiler/heptagon/transformations/last.ml
@@ -11,13 +11,17 @@ open Heptagon
 open Hept_mapfold
 open Idents
 
+
+let fresh = Idents.gen_fresh "last" Idents.name
+
+
 (* introduce a fresh equation [last_x = pre(x)] for every *)
 (* variable declared with a last *)
 let last (eq_list, env, v) { v_ident = n; v_type = t; v_last = last } =
   match last with
     | Var -> (eq_list, env, v)
     | Last(default) ->
-        let lastn = Idents.fresh ("last" ^ (sourcename n)) in
+        let lastn = fresh n in
         let eq = mk_equation (Eeq (Evarpat lastn,
                                    mk_exp (Epre (default,
                                                  mk_exp (Evar n) t)) t)) in
@@ -39,6 +43,7 @@ let block funs env b =
         b_equs = eq_lastn_n_list @ b.b_equs }, env
 
 let node_dec funs _ n =
+  Idents.enter_node n.n_name;
   let _, env, _ = extend_env Env.empty n.n_input in
   let eq_lasto_list, env, last_o = extend_env env n.n_output in
   let n, _  = Hept_mapfold.node_dec funs env n in
diff --git a/compiler/heptagon/transformations/reset.ml b/compiler/heptagon/transformations/reset.ml
index 244a617..0fecdf2 100644
--- a/compiler/heptagon/transformations/reset.ml
+++ b/compiler/heptagon/transformations/reset.ml
@@ -45,6 +45,11 @@ open Initial
    e1 -> e2 is translated into if (true fby false) then e1 else e2
 *)
 
+
+
+let fresh = Idents.gen_fresh "reset" (fun () -> "r")
+
+
 let mk_bool_var n = mk_exp (Evar n) (Tid Initial.pbool)
 let mk_bool_param n = mk_var_dec n (Tid Initial.pbool)
 
@@ -73,7 +78,7 @@ let ifres res e2 e3 =
 
 (* add an equation *)
 let equation v acc_eq_list e =
-  let n = Idents.fresh "r" in
+  let n = fresh() in
   n,
   (mk_bool_param n) :: v,
   (mk_equation (Eeq(Evarpat n, e))) ::acc_eq_list
@@ -133,8 +138,8 @@ let edesc funs (res, v, acc_eq_list) ed =
 
 let switch_handlers funs (res, v, acc_eq_list) switch_handlers =
   (* introduce a reset bit for each branch *)
-  let m_list = List.map (fun _ -> Idents.fresh "r") switch_handlers in
-  let lm_list = List.map (fun _ -> Idents.fresh "r") switch_handlers in
+  let m_list = List.map (fun {w_name = c} -> fresh()) switch_handlers in
+  let lm_list = List.map (fun {w_name = c} -> fresh()) switch_handlers in
 
   let body i ({ w_block = b } as sh) m lm =
     let defnames = List.fold_left (fun acc m ->
diff --git a/compiler/main/hept2mls.ml b/compiler/main/hept2mls.ml
index 3403f1b..5baeeb6 100644
--- a/compiler/main/hept2mls.ml
+++ b/compiler/main/hept2mls.ml
@@ -90,7 +90,7 @@ end
 
 (* add an equation *)
 let equation locals l_eqs e =
-  let n = Idents.fresh "ck" in
+  let n = Idents.gen_var "hept2mls" "ck" in
   n,
   (mk_var_dec n e.e_ty) :: locals,
   (mk_equation (Evarpat n) e):: l_eqs
@@ -260,7 +260,7 @@ let rec translate_pat = function
 let rec rename_pat ni locals s_eqs = function
   | Heptagon.Evarpat(n), ty ->
       if IdentSet.mem n ni then (
-        let n_copy = Idents.fresh (sourcename n) in
+        let n_copy = Idents.gen_var "hept2mls" (name n) in
         Evarpat n_copy,
         (mk_var_dec n_copy ty) :: locals,
         add n (mk_exp ~ty:ty (Evar n_copy)) s_eqs
@@ -352,7 +352,7 @@ let translate_contract env contract =
                                   Heptagon.b_equs = eq_list };
              Heptagon.c_assume = e_a;
              Heptagon.c_enforce = e_g;
-						 Heptagon.c_controllables = l_c } ->
+             Heptagon.c_controllables = l_c } ->
         let env' = Env.add v env in
         let locals = translate_locals [] v in
         let locals, l_eqs, s_eqs =
@@ -360,12 +360,12 @@ let translate_contract env contract =
         let l_eqs, _ = add_locals IdentSet.empty l_eqs [] s_eqs in
         let e_a = translate env' e_a in
         let e_g = translate env' e_g in
-				let env = Env.add l_c env in
+        let env = Env.add l_c env in
         Some { c_local = locals;
                c_eq = l_eqs;
                c_assume = e_a;
                c_enforce = e_g;
-							 c_controllables = List.map translate_var l_c },
+               c_controllables = List.map translate_var l_c },
         env
 
 
@@ -387,7 +387,7 @@ let node
     n_input = List.map translate_var i;
     n_output = List.map translate_var o;
     n_contract = contract;
-		n_controller_call = ([],[]);
+    n_controller_call = ([],[]);
     n_local = locals;
     n_equs = l_eqs;
     n_loc = loc ;
diff --git a/compiler/main/heptc.ml b/compiler/main/heptc.ml
index dc1f1a2..a7a8878 100644
--- a/compiler/main/heptc.ml
+++ b/compiler/main/heptc.ml
@@ -90,7 +90,7 @@ let main () =
         "-nopervasives", Arg.Unit set_no_pervasives, doc_no_pervasives;
         "-target", Arg.String add_target_language, doc_target;
         "-targetpath", Arg.String set_target_path, doc_target_path;
-				"-nocaus", Arg.Clear causality, doc_nocaus;
+        "-nocaus", Arg.Clear causality, doc_nocaus;
         "-noinit", Arg.Clear init, doc_noinit;
         "-fti", Arg.Set full_type_info, doc_full_type_info;
         "-itfusion", Arg.Set do_iterator_fusion, doc_itfusion;
diff --git a/compiler/main/mls2obc.ml b/compiler/main/mls2obc.ml
index 2fd1acc..6bced29 100644
--- a/compiler/main/mls2obc.ml
+++ b/compiler/main/mls2obc.ml
@@ -19,6 +19,8 @@ open Static
 open Obc_mapfold
 open Initial
 
+let fresh_it () = Idents.gen_var "mls2obc" "i"
+
 (** Not giving any type and called after typing, DO NOT use it anywhere else *)
 let static_exp_of_int i =
   Types.mk_static_exp (Types.Sint i)
@@ -131,8 +133,8 @@ and translate_act map pat
 
     | Minils.Evarpat x,
                 Minils.Eapp ({ Minils.a_op = Minils.Econcat }, [e1; e2], _) ->
-        let cpt1 = Idents.fresh "i" in
-        let cpt2 = Idents.fresh "i" in
+        let cpt1 = fresh_it () in
+        let cpt2 = fresh_it () in
         let x = var_from_name map x in
         (match e1.Minils.e_ty, e2.Minils.e_ty with
            | Tarray (_, n1), Tarray (_, n2) ->
@@ -157,7 +159,7 @@ and translate_act map pat
     | Minils.Evarpat x,
               Minils.Eapp ({ Minils.a_op = Minils.Earray_fill;
                              Minils.a_params = [n] }, [e], _) ->
-        let cpt = Idents.fresh "i" in
+        let cpt = fresh_it () in
         let e = translate map e in
           [ Afor (cpt, mk_static_int 0, n,
                   mk_block [Aassgn (mk_lhs (Larray (var_from_name map x,
@@ -166,7 +168,7 @@ and translate_act map pat
     | Minils.Evarpat x,
         Minils.Eapp ({ Minils.a_op = Minils.Eselect_slice;
                        Minils.a_params = [idx1; idx2] }, [e], _) ->
-        let cpt = Idents.fresh "i" in
+        let cpt = fresh_it () in
         let e = translate map e in
         let idx = mk_exp (Eop (op_from_string "+",
                                [mk_evar cpt;
@@ -296,7 +298,7 @@ let rec translate_eq map call_context { Minils.eq_lhs = pat; Minils.eq_rhs = e }
         let name_list = translate_pat map pat in
         let c_list =
           List.map (translate map) e_list in
-        let x = Idents.fresh "i" in
+        let x = fresh_it () in
         let call_context = Oarray ("n", mk_lhs (Lvar x)), Some n in
         let si', j', action = translate_iterator map call_context it
           name_list app loc n x c_list in
diff --git a/compiler/minils/analysis/clocking.ml b/compiler/minils/analysis/clocking.ml
index 3fbe459..b13cc27 100644
--- a/compiler/minils/analysis/clocking.ml
+++ b/compiler/minils/analysis/clocking.ml
@@ -140,7 +140,7 @@ let typing_contract h contract base =
              c_eq = eq_list;
              c_assume = e_a;
              c_enforce = e_g;
-						 c_controllables = c_list } ->
+             c_controllables = c_list } ->
         let h' = build h l_list in
         (* assumption *)
         (* property *)
diff --git a/compiler/minils/main/mls2seq.ml b/compiler/minils/main/mls2seq.ml
index bfbd199..8df6acf 100644
--- a/compiler/minils/main/mls2seq.ml
+++ b/compiler/minils/main/mls2seq.ml
@@ -30,7 +30,7 @@ let write_object_file p =
     close_out epoc;
     comment "Generating of object file"
 
-(** Writes a .epo file for program [p]. *)
+(** Writes a .obc file for program [p]. *)
 let write_obc_file p =
   let obc_name = (filename_of_name p.Obc.p_modname)^".obc" in
   let obc = open_out obc_name in
diff --git a/compiler/minils/minils.ml b/compiler/minils/minils.ml
index 7d15357..ad40894 100644
--- a/compiler/minils/minils.ml
+++ b/compiler/minils/minils.ml
@@ -146,13 +146,13 @@ let mk_equation ?(loc = no_location) pat exp =
 
 let mk_node
     ?(input = []) ?(output = []) ?(contract = None) ?(local = []) ?(eq = [])
-    ?(loc = no_location) ?(param = []) ?(constraints = []) 
-		?(pinst = ([],[])) name =
+    ?(loc = no_location) ?(param = []) ?(constraints = [])
+    ?(pinst = ([],[])) name =
   { n_name = name;
     n_input = input;
     n_output = output;
     n_contract = contract;
-		n_controller_call = pinst;
+    n_controller_call = pinst;
     n_local = local;
     n_equs = eq;
     n_loc = loc;
diff --git a/compiler/minils/mls_mapfold.ml b/compiler/minils/mls_mapfold.ml
index 07fb58a..314ff4b 100644
--- a/compiler/minils/mls_mapfold.ml
+++ b/compiler/minils/mls_mapfold.ml
@@ -49,7 +49,7 @@ and edesc funs acc ed = match ed with
   | Econst se ->
       let se, acc = static_exp_it funs.global_funs acc se in
         Econst se, acc
-  | Evar x -> ed, acc
+  | Evar _ -> ed, acc
   | Efby (se, e) ->
       let se, acc = optional_wacc (static_exp_it funs.global_funs) acc se in
       let e, acc = exp_it funs acc e in
@@ -126,7 +126,9 @@ and contract funs acc c =
   , acc
 
 
-and node_dec_it funs acc nd = funs.node_dec funs acc nd
+and node_dec_it funs acc nd =
+  Idents.enter_node nd.n_name;
+  funs.node_dec funs acc nd
 and node_dec funs acc nd =
   let n_input, acc = var_decs_it funs acc nd.n_input in
   let n_output, acc = var_decs_it funs acc nd.n_output in
diff --git a/compiler/minils/mls_printer.ml b/compiler/minils/mls_printer.ml
index a6c5f32..8bebfc0 100644
--- a/compiler/minils/mls_printer.ml
+++ b/compiler/minils/mls_printer.ml
@@ -189,7 +189,7 @@ let rec print_type_dec ff { t_name = name; t_desc = tdesc } =
 
 let print_contract ff { c_local = l; c_eq = eqs;
                         c_assume = e_a; c_enforce = e_g;
-			c_controllables = c;} =
+      c_controllables = c;} =
   fprintf ff "@[<v2>contract@\n%a%a@ assume %a@ enforce %a@ with (%a)@]"
     print_local_vars l
     print_eqs eqs
diff --git a/compiler/minils/parsing/mls_parser.mly b/compiler/minils/parsing/mls_parser.mly
index 73b2048..c028adc 100644
--- a/compiler/minils/parsing/mls_parser.mly
+++ b/compiler/minils/parsing/mls_parser.mly
@@ -118,10 +118,10 @@ node_dec:
   NODE n=qualname p=params(n_param) LPAREN args=args RPAREN
   RETURNS LPAREN out=args RPAREN
   contract=contract vars=loc_vars eqs=equs
-      { mk_node p args out vars eqs 
-	  ~loc:(Loc ($startpos,$endpos))
-	  ~contract:contract
-	  n }
+      { mk_node p args out vars eqs
+    ~loc:(Loc ($startpos,$endpos))
+    ~contract:contract
+    n }
 
 
 contract:
@@ -129,14 +129,14 @@ contract:
   | CONTRACT
     locvars=loc_vars
     eqs=opt_equs
-    assume=opt_assume 
-    enforce=opt_enforce 
+    assume=opt_assume
+    enforce=opt_enforce
     withvar=opt_with
       { Some{ c_local=locvars;
-	      c_equs=eqs;
+        c_equs=eqs;
               c_assume = assume;
               c_enforce = enforce;
-	      c_controllables = withvar } }
+        c_controllables = withvar } }
 ;
 
 opt_assume:
@@ -181,7 +181,7 @@ var:
   | ns=snlist(COMMA, NAME) COLON t=type_ident c=clock_annot
       { List.map (fun n -> mk_var_dec n t c (Loc ($startpos,$endpos))) ns }
 
-opt_equs: 
+opt_equs:
   | /* empty */ { [] }
   | LET e=slist(SEMICOL, equ) TEL { e }
 
diff --git a/compiler/minils/transformations/callgraph.ml b/compiler/minils/transformations/callgraph.ml
index 46fe579..928f006 100644
--- a/compiler/minils/transformations/callgraph.ml
+++ b/compiler/minils/transformations/callgraph.ml
@@ -92,14 +92,16 @@ struct
       [ln] with the static parameters [params] and stores it. *)
   let generate_new_name ln params = match params with
     | [] -> nodes_names := M.add (ln, params) ln !nodes_names
-    | _ -> let { qual = q; name = n } = ln in
-           let new_ln = { qual = q;
-                  (* TODO ??? c'est quoi ce nom ??? *)
-                  (* l'utilite de fresh n'est vrai que si toute les fonctions
-                     sont touchees.. ce qui n'est pas vrai cf main_nodes *)
-                  (* TODO mettre les valeurs des params dans le nom *)
-                          name = n^(Idents.name (Idents.fresh "")) } in
-           nodes_names := M.add (ln, params) new_ln !nodes_names
+    | _ ->
+        let { qual = q; name = n } = ln in
+        let param_string =
+          List.fold_left
+            (fun s se ->
+              s ^ (Names.print_pp_to_name Global_printer.print_static_exp se))
+            "_params_" params in
+        let new_ln =
+          Modules.fresh_value_in "callgraph" (n^param_string^"_") q in
+        nodes_names := M.add (ln, params) new_ln !nodes_names
 
   (** Adds an instance of a node. *)
   let add_node_instance ln params =
@@ -167,6 +169,7 @@ struct
       in ed, m
 
     let node_dec_instance modname n params =
+      Idents.enter_node n.n_name;
       let global_funs =
         { Global_mapfold.defaults with static_exp = static_exp } in
       let funs =
@@ -301,9 +304,9 @@ let program p =
   (* Find the nodes without static parameters *)
   let main_nodes = List.filter (fun n -> is_empty n.n_params) p.p_nodes in
   let main_nodes = List.map (fun n -> n.n_name, []) main_nodes in
-    info.opened <- NamesEnv.add p.p_modname p NamesEnv.empty;
-    (* Creates the list of instances starting from these nodes *)
-    List.iter call_node main_nodes;
-    let p_list = NamesEnv.fold (fun _ p l -> p::l) info.opened [] in
-      (* Generate all the needed instances *)
-      List.map Param_instances.Instantiate.program p_list
+  info.opened <- NamesEnv.add p.p_modname p NamesEnv.empty;
+  (* Creates the list of instances starting from these nodes *)
+  List.iter call_node main_nodes;
+  let p_list = NamesEnv.fold (fun _ p l -> p::l) info.opened [] in
+  (* Generate all the needed instances *)
+  List.map Param_instances.Instantiate.program p_list
diff --git a/compiler/minils/transformations/checkpass.ml b/compiler/minils/transformations/checkpass.ml
index 3b39b26..437c519 100644
--- a/compiler/minils/transformations/checkpass.ml
+++ b/compiler/minils/transformations/checkpass.ml
@@ -26,7 +26,7 @@ let add_check prefix pass nd nd_list =
     let nd'_name = { nd.n_name with name = prefix ^ "_" ^ nd.n_name.name; } in
     let nd' = pass nd in
     let nd' = { nd' with n_name = nd'_name; } in
-    let output = Idents.fresh "o" in
+    let output = Idents.gen_var "checkpass" "o" in
 
     let echeck =
       let ty_r = match nd.n_output with
diff --git a/compiler/minils/transformations/introvars.ml b/compiler/minils/transformations/introvars.ml
index f48fb08..f0c910b 100644
--- a/compiler/minils/transformations/introvars.ml
+++ b/compiler/minils/transformations/introvars.ml
@@ -93,7 +93,7 @@ and intro_var e (eq_list, var_list) =
   match e.e_desc with
     | Evar _ -> (e, eq_list, var_list)
     | _ ->
-        let id = Idents.fresh prefix in
+        let id = Idents.gen_var "introvars" prefix in
         let new_eq = mk_equation (Evarpat id) e
         and var_dc = mk_var_dec id e.e_ty in
         (mk_exp ~ty:e.e_ty (Evar id), new_eq :: eq_list, var_dc :: var_list)
diff --git a/compiler/minils/transformations/itfusion.ml b/compiler/minils/transformations/itfusion.ml
index 7c8b7b0..f3effeb 100644
--- a/compiler/minils/transformations/itfusion.ml
+++ b/compiler/minils/transformations/itfusion.ml
@@ -7,8 +7,15 @@ open Minils
 (* Iterator fusion *)
 
 (* Functions to temporarily store anonymous nodes*)
-let mk_fresh_node_name () =
-  current_qual (Idents.name (Idents.fresh "_n_"))
+let mk_fresh_node_name () = Modules.fresh_value "itfusion" "temp"
+
+let fresh_vd_of_arg =
+  Idents.gen_fresh "itfusion"
+                   (fun a -> match a.a_name with
+                             | None -> "v"
+                             | Some n -> n)
+
+let fresh_var = Idents.gen_fresh "itfusion" (fun () -> "x")
 
 let anon_nodes = ref QualEnv.empty
 
@@ -44,8 +51,7 @@ let tuple_of_vd_list l =
     mk_exp ~ty:ty (Eapp (mk_app Etuple, el, None))
 
 let vd_of_arg ad =
-  let n = match ad.a_name with None -> "_v" | Some n -> n in
-    mk_var_dec (Idents.fresh n) ad.a_type
+    mk_var_dec (fresh_vd_of_arg ad) ad.a_type
 
 (** @return the lists of inputs and outputs (as var_dec) of
     an app object. *)
@@ -100,7 +106,7 @@ let edesc funs acc ed =
               let new_inp, e, acc_eq_list = mk_call g acc_eq_list in
                 new_inp @ inp, acc_eq_list, e::largs, local_args @ args, true
           | _ ->
-              let vd = mk_var_dec (Idents.fresh "_x") e.e_ty in
+              let vd = mk_var_dec (fresh_var ()) e.e_ty in
               let x = mk_exp (Evar vd.v_ident) in
               vd::inp, acc_eq_list, x::largs, e::args, b
         in
diff --git a/compiler/minils/transformations/normalize.ml b/compiler/minils/transformations/normalize.ml
index cbd4f53..a15d639 100644
--- a/compiler/minils/transformations/normalize.ml
+++ b/compiler/minils/transformations/normalize.ml
@@ -25,7 +25,7 @@ let flatten_e_list l =
 
 let equation (d_list, eq_list) e =
   let add_one_var ty d_list =
-    let n = Idents.fresh "_v" in
+    let n = Idents.gen_var "normalize" "v" in
     let d_list = (mk_var_dec ~clock:e.e_ck n ty) :: d_list in
       n, d_list
   in
@@ -306,7 +306,7 @@ and fby kind context e v e1 =
         let e_list = List.map mk_pre e_list in
         let e = { e with e_desc = Eapp(app, e_list, r) } in
           translate kind context e
-    | Econst { se_desc = Stuple se_list }, None ->
+    | Econst { se_desc = Stuple _ }, None ->
         context, e1
     | _ ->
         let context, e1' =
diff --git a/compiler/minils/transformations/singletonvars.ml b/compiler/minils/transformations/singletonvars.ml
index deb22d3..cbea34f 100644
--- a/compiler/minils/transformations/singletonvars.ml
+++ b/compiler/minils/transformations/singletonvars.ml
@@ -59,7 +59,7 @@ struct
 
   let node nd =
     let funs = { Mls_mapfold.defaults with Mls_mapfold.edesc = edesc; } in
-    snd (Mls_mapfold.node_dec funs Env.empty nd)
+    snd (Mls_mapfold.node_dec_it funs Env.empty nd)
 end
 
 module InlineSingletons =
@@ -72,7 +72,7 @@ struct
 
   let inline_node subst nd =
     let funs = { Mls_mapfold.defaults with Mls_mapfold.exp = exp; } in
-    fst (Mls_mapfold.node_dec funs subst nd)
+    fst (Mls_mapfold.node_dec_it funs subst nd)
 
   let inline_exp subst e =
     let funs = { Mls_mapfold.defaults with
diff --git a/compiler/minils/transformations/tomato.ml b/compiler/minils/transformations/tomato.ml
index 5519839..5b358dc 100644
--- a/compiler/minils/transformations/tomato.ml
+++ b/compiler/minils/transformations/tomato.ml
@@ -32,7 +32,7 @@ let ident_of_int =
   fun (name : string) (i : int) ->
     try Hashtbl.find ht i
     with Not_found ->
-      let new_ident = Idents.fresh name in
+      let new_ident = Idents.gen_var "tomato" name in
       Hashtbl.add ht i new_ident;
       new_ident
 
@@ -151,10 +151,10 @@ struct
     let funs = { Mls_mapfold.defaults with
                    Mls_mapfold.exp = exp;
                    Mls_mapfold.var_dec = var_dec; } in
-    fst (Mls_mapfold.node_dec funs subst nd)
+    fst (Mls_mapfold.node_dec_it funs subst nd)
 end
 
-let empty_var = Idents.fresh "EMPTY"
+let empty_var = Idents.gen_var "tomato" "EMPTY"
 let dummy_exp = mk_exp (Evar empty_var)
 
 let exp_of_ident vi = mk_exp (Evar vi)
@@ -460,7 +460,7 @@ let introduce_copies_for_outputs nd =
   let var_dec vd (iset, vd_list, eq_list) =
     if IdentSet.mem vd.v_ident iset
     then (* introduce copy, change vd *)
-      let fresh = Idents.fresh (Idents.name vd.v_ident) in
+      let fresh = Idents.gen_var "tomato" (Idents.name vd.v_ident) in
       let new_eq =
         let e = mk_exp ~ty:vd.v_type (Evar vd.v_ident) in
         mk_equation (Evarpat fresh) e in
diff --git a/compiler/obc/c/cmain.ml b/compiler/obc/c/cmain.ml
index 1b1a2a8..d295da5 100644
--- a/compiler/obc/c/cmain.ml
+++ b/compiler/obc/c/cmain.ml
@@ -24,9 +24,13 @@ open Compiler_utils
 
 (** {1 Main C function generation} *)
 
+let _ = Idents.enter_node (Modules.fresh_value "cmain" "main")
+
+let fresh n = Idents.name (Idents.gen_var "cmain" n)
+
 (* Unique names for C variables handling step counts. *)
-let step_counter = Idents.fresh "step_c"
-and max_step = Idents.fresh "step_max"
+let step_counter = fresh "step_c"
+and max_step = fresh"step_max"
 
 let assert_node_res cd =
   let stepm = find_step_method cd in
@@ -43,10 +47,10 @@ let assert_node_res cd =
      exit 1);
   let name = cname_of_qn cd.cd_name in
   let mem =
-    (Idents.name (Idents.fresh ("mem_for_" ^ name)),
+    (fresh ("mem_for_" ^ name),
       Cty_id (qn_append cd.cd_name "_mem"))
   and out =
-    (Idents.name (Idents.fresh ("out_for_" ^ name)),
+    (fresh ("out_for_" ^ name),
       Cty_id (qn_append cd.cd_name "_out")) in
   let reset_i =
     Cfun_call (name ^ "_reset", [Caddrof (Cvar (fst mem))]) in
@@ -71,7 +75,7 @@ let assert_node_res cd =
                                      [Cconst (Cstrlit ("Node \\\"" ^ name
                                                        ^ "\\\" failed at step" ^
                                                        " %d.\\n"));
-                                      Clhs (Cvar (Idents.name step_counter))]));
+                                      Clhs (Cvar step_counter)]));
                   Creturn (Cconst (Ccint 1))],
                  []);
           ];
@@ -104,7 +108,7 @@ let main_def_of_class_def cd =
   (** Generates scanf statements. *)
   let rec read_lhs_of_ty lhs ty = match ty with
     | Tarray (ty, n) ->
-        let iter_var = Idents.name (Idents.fresh "i") in
+        let iter_var = fresh "i" in
         let lhs = Carray (lhs, Clhs (Cvar iter_var)) in
         let (reads, bufs) = read_lhs_of_ty lhs ty in
         ([Cfor (iter_var, 0, int_of_static_exp n, reads)], bufs)
@@ -130,7 +134,7 @@ let main_def_of_class_def cd =
         match need_buf_for_ty ty with
           | None -> ([scan_exp], [])
           | Some tyn ->
-              let varn = Idents.name (Idents.fresh "buf") in
+              let varn = fresh "buf" in
               ([scan_exp;
                 Csexpr (Cfun_call (tyn ^ "_of_string",
                                    [Clhs (Cvar varn)]))],
@@ -140,14 +144,14 @@ let main_def_of_class_def cd =
       resulting values of enum types. *)
   let rec write_lhs_of_ty lhs ty = match ty with
     | Tarray (ty, n) ->
-        let iter_var = Idents.name (Idents.fresh "i") in
+        let iter_var = fresh "i" in
         let lhs = Carray (lhs, Clhs (Cvar iter_var)) in
         let (reads, bufs) = write_lhs_of_ty lhs ty in
         ([cprint_string "[ ";
           Cfor (iter_var, 0, int_of_static_exp n, reads);
           cprint_string "]"], bufs)
     | _ ->
-        let varn = Idents.name (Idents.fresh "buf") in
+        let varn = fresh "buf" in
         let format_s = format_for_type ty in
         let nbuf_opt = need_buf_for_ty ty in
         let ep = match nbuf_opt with
@@ -217,7 +221,7 @@ let main_skel var_list prologue body =
     f_args = [("argc", Cty_int); ("argv", Cty_ptr (Cty_ptr Cty_char))];
     f_body = {
       var_decls =
-        (name step_counter, Cty_int) :: (name max_step, Cty_int) :: var_list;
+        (step_counter, Cty_int) :: (max_step, Cty_int) :: var_list;
       block_body =
         [
           (*
@@ -226,10 +230,10 @@ let main_skel var_list prologue body =
             if (argc == 2)
               max_step = atoi(argv[1]);
           *)
-          Caffect (Cvar (name step_counter), Cconst (Ccint 0));
-          Caffect (Cvar (name max_step), Cconst (Ccint 0));
+          Caffect (Cvar step_counter, Cconst (Ccint 0));
+          Caffect (Cvar max_step, Cconst (Ccint 0));
           Cif (Cbop ("==", Clhs (Cvar "argc"), Cconst (Ccint 2)),
-               [Caffect (Cvar (name max_step),
+               [Caffect (Cvar max_step,
                          Cfun_call ("atoi",
                                     [Clhs (Carray (Cvar "argv",
                                                    Cconst (Ccint 1)))]))], []);
@@ -238,14 +242,14 @@ let main_skel var_list prologue body =
           (* while (!max_step || step_c < max_step) *)
         @ [
           Cwhile (Cbop ("||",
-                        Cuop ("!", Clhs (Cvar (name max_step))),
+                        Cuop ("!", Clhs (Cvar max_step)),
                         Cbop ("<",
-                              Clhs (Cvar (name step_counter)),
-                              Clhs (Cvar (name max_step)))),
+                              Clhs (Cvar step_counter),
+                              Clhs (Cvar max_step))),
                   (* step_counter = step_counter + 1; *)
-                  Caffect (Cvar (name step_counter),
+                  Caffect (Cvar step_counter,
                            Cbop ("+",
-                                 Clhs (Cvar (name step_counter)),
+                                 Clhs (Cvar step_counter),
                                  Cconst (Ccint 1)))
                   :: body);
           Creturn (Cconst (Ccint 0));
diff --git a/compiler/utilities/misc.ml b/compiler/utilities/misc.ml
index 206790b..e3ca75e 100644
--- a/compiler/utilities/misc.ml
+++ b/compiler/utilities/misc.ml
@@ -30,6 +30,17 @@ let rec split_string s c =
   with Not_found -> [s]
 
 
+(** Print to a string *)
+let print_pp_to_string print_fun element =
+  let _ = Format.flush_str_formatter () in (* Ensure that the buffer is empty *)
+  print_fun Format.str_formatter element;
+  Format.flush_str_formatter ()
+
+(** Replace all non [a-z A-Z 0-9] character of a string by [_] *)
+let sanitize_string s =
+  Str.global_replace (Str.regexp "[^a-zA-Z0-9]") "_" s
+
+
 (* creation of names. Ensure unicity for the whole compilation chain *)
 let symbol = ref 0
 
diff --git a/compiler/utilities/misc.mli b/compiler/utilities/misc.mli
index a332b87..d8583ab 100644
--- a/compiler/utilities/misc.mli
+++ b/compiler/utilities/misc.mli
@@ -76,3 +76,10 @@ val assert_1min : 'a list -> 'a * 'a list
 val assert_2 : 'a list -> 'a * 'a
 val assert_2min : 'a list -> 'a * 'a * 'a list
 val assert_3 : 'a list -> 'a * 'a * 'a
+
+(** Print to string *)
+val print_pp_to_string : (Format.formatter -> 'a -> unit) -> 'a -> string
+
+(** Replace all non [a-z A-Z 0-9] character of a string by [_] *)
+val sanitize_string : string -> string
+