heptagon/compiler/global/idents.ml
Léonard Gérard 2ae809c971 Fresh vars, and ident refactoring.
Idents.enter_node should be called when entering a node, it is done automagically by the mapfold unless you call directly Hept_mapfold.node_dec.
2010-12-15 11:26:29 +01:00

136 lines
4 KiB
OCaml

(**************************************************************************)
(* *)
(* Heptagon *)
(* *)
(* Author : Marc Pouzet *)
(* Organization : Demons, LRI, University of Paris-Sud, Orsay *)
(* *)
(**************************************************************************)
(* 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 *)
source : string; (* the original name in the source *)
is_generated : bool;
}
type var_ident = ident
let num = ref 0
let ident_compare id1 id2 = compare id1.num id2.num
(* used only for debuging *)
let name id =
if id.is_generated then
id.source ^ "_" ^ (string_of_int id.num)
else
id.source
(* used only for debuging *)
let fprint_t ff id = Format.fprintf ff "%s" (name id)
module M = struct
type t = ident
let compare = ident_compare
let fprint = fprint_t
end
module Env =
struct
include (Map.Make(M))
let append env0 env =
fold (fun key v env -> add key v env) env0 env
(* Environments union *)
let union env1 env2 =
fold (fun name elt env -> add name elt env) env2 env1
(* Environments difference : env1 - env2 *)
let diff env1 env2 =
fold (fun name _ env -> remove name env) env2 env1
(* Environments partition *)
let partition p env =
fold
(fun key elt (env1,env2) ->
if p(key)
then ((add key elt env1),env2)
else (env1,(add key elt env2)))
env
(empty, empty)
end
module IdentSet = struct
include (Set.Make(M))
let fprint_t ff s =
Format.fprintf ff "@[<hov>{@ ";
iter (fun e -> Format.fprintf ff "%a@ " M.fprint e) s;
Format.fprintf ff "}@]";
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
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
(** 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
there is a collision. *)
let assign_name n =
let fresh s =
num := !num + 1;
s ^ "_" ^ (string_of_int !num) in
let rec fresh_string base =
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 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 enter_node n = UniqueNames.enter_node n
let print_ident ff id = Format.fprintf ff "%s" (name id)