1 files changed, 99 insertions, 0 deletions
diff --git a/minijazz/src/analysis/scoping.ml b/minijazz/src/analysis/scoping.ml
new file mode 100644
index 0000000..0fefd5b
--- /dev/null
+++ b/minijazz/src/analysis/scoping.ml
@@ -0,0 +1,99 @@
+open Ast
+open Mapfold
+open Static
+open Static_utils
+open Location
+open Errors
+
+(** Simplifies static expression in the program. *)
+let simplify_program p =
+  let const_dec funs cenv cd =
+    let v = subst cenv cd.c_value in
+    let cenv = NameEnv.add cd.c_name v cenv in
+    { cd with c_value = v }, cenv
+  in
+  let static_exp funs cenv se =
+    let se = subst cenv se in
+    (match se.se_desc with
+      | SVar id ->
+          (* Constants with se.se_loc = no_location are generated and should not be checked *)
+          if not (NameEnv.mem id cenv) && not (se.se_loc == no_location) then (
+            Format.eprintf "%aThe constant name '%s' is unbound@."
+              print_location se.se_loc id;
+            raise Error
+          )
+      | _ -> ()
+    );
+    se, cenv
+  in
+  let node_dec funs cenv nd =
+    let cenv' =
+      List.fold_left
+        (fun cenv p -> NameEnv.add p.p_name (mk_static_var p.p_name) cenv)
+        cenv nd.n_params
+    in
+    let nd, _ = Mapfold.node_dec funs cenv' nd in
+    nd, cenv
+  in
+  let funs =
+    { Mapfold.defaults with const_dec = const_dec;
+      static_exp = static_exp; node_dec = node_dec }
+  in
+  let p, _ = Mapfold.program_it funs NameEnv.empty p in
+  p
+
+(** Checks the name used in the program are defined.
+    Adds var_decs for all variables defined in a block. *)
+let check_names p =
+  let rec pat_vars s pat = match pat with
+    | Evarpat id -> IdentSet.add id s
+    | Etuplepat ids -> List.fold_left (fun s id -> IdentSet.add id s) s ids
+  in
+  let build_set vds =
+    List.fold_left (fun s vd -> IdentSet.add vd.v_ident s) IdentSet.empty vds
+  in
+  let block funs (s, _) b = match b with
+    | BEqs(eqs, _) ->
+        let defnames = List.fold_left (fun s (pat, _) -> pat_vars s pat) IdentSet.empty eqs in
+        let ls = IdentSet.diff defnames s in (* remove outputs from the set *)
+        let vds = IdentSet.fold (fun id l -> (mk_var_dec id invalid_type)::l) ls [] in
+        let new_s = IdentSet.union s defnames in
+        let eqs,_ = Misc.mapfold (Mapfold.equation_it funs) (new_s, IdentSet.empty) eqs in
+        BEqs (eqs, vds), (s, defnames)
+    | BIf(se, trueb, falseb) ->
+        let trueb, (_, def_true) = Mapfold.block_it funs (s, IdentSet.empty) trueb in
+        let falseb, (_, def_false) = Mapfold.block_it funs (s, IdentSet.empty) falseb in
+        let defnames = IdentSet.inter def_true def_false in
+        BIf(se, trueb, falseb), (s, defnames)
+  in
+  let exp funs (s, defnames) e = match e.e_desc with
+    | Evar id ->
+        if not (IdentSet.mem id s) then (
+          Format.eprintf "%aThe identifier '%a' is unbound@."
+            print_location e.e_loc Ident.print_ident id;
+          raise Error
+        );
+        e, (s, defnames)
+    | _ -> Mapfold.exp funs (s, defnames) e
+  in
+  let node n =
+    let funs = { Mapfold.defaults with block = block; exp = exp } in
+    let s = build_set (n.n_inputs@n.n_outputs) in
+    let n_body, (_, defnames) = Mapfold.block_it funs (s, IdentSet.empty) n.n_body in
+    (* check for undefined outputs *)
+    let undefined_outputs =
+      List.filter (fun vd -> not (IdentSet.mem vd.v_ident defnames)) n.n_outputs
+    in
+    if undefined_outputs <> [] then (
+      Format.eprintf "%aThe following outputs are not defined: %a@."
+        print_location n.n_loc  Printer.print_var_decs undefined_outputs;
+      raise Error
+    );
+    { n with n_body = n_body }
+  in
+  { p with p_nodes = List.map node p.p_nodes }
+
+
+let program p =
+  let p = simplify_program p in
+  check_names p