compilateurMIPS/semantics.ml

open Ast
open Ast.IR
open Baselib
open Errors

let analyze_value = function
  | Syntax.Void -> Void, Void_t
  | Syntax.Int n -> Int n, Int_t
  | Syntax.Bool b -> Bool b, Bool_t
;;

let rec analyze_expr env ua t = function
  | Syntax.Val v ->
    let v2, new_t = analyze_value v.value in
    if new_t != t then errt t new_t v.pos;
    Val v2, new_t
  | Syntax.Var v ->
    if not (Env.mem v.name env)
    then raise (SemanticsError ("Unbound variable \"" ^ v.name ^ "\"", v.pos));
    if List.mem v.name ua then warn ("Unassigned variable \"" ^ v.name ^ "\"") v.pos;
    let new_t = Env.find v.name env in
    if new_t != t then errt t new_t v.pos;
    Var v.name, new_t
  | Syntax.Call c ->
    (match Env.find c.func env with
    | Func_t (ret_t, tl) ->
      if ret_t != t then errt t ret_t c.pos;
      ( Call
          ( c.func
          , List.map2
              (fun t e ->
                let e2, t2 = analyze_expr env ua t e in
                if t2 = t
                then e2
                else
                  errt
                    t
                    t2
                    (match e with
                    | Syntax.Val v -> v.pos
                    | Syntax.Var v -> v.pos
                    | Syntax.Call c -> c.pos))
              tl
              c.args )
      , ret_t )
    | _ -> raise (SemanticsError ("\"" ^ c.func ^ "\" isn't a function", c.pos)))
;;

let analyze_instr env ua = function
  | Syntax.Decl d -> Decl d.name, Env.add d.name d.type_t env, [ d.name ] @ ua
  | Syntax.Assign a ->
    if not (Env.mem a.var env)
    then raise (SemanticsError ("Unbound variable \"" ^ a.var ^ "\"", a.pos));
    let ae, et = analyze_expr env ua (Env.find a.var env) a.expr in
    Assign (a.var, ae), env, List.filter (fun x -> x <> a.var) ua
  | Syntax.Do d ->
    let ae, _ = analyze_expr env ua Int_t d.expr in
    Do ae, env, []
  | Syntax.Return r ->
    let ae, _ = analyze_expr env ua Int_t r.expr in
    Return ae, env, []
;;

let rec analyze_block env ua = function
  | [] -> []
  | instr :: new_block ->
    let new_instr, new_env, new_ua = analyze_instr env ua instr in
    new_instr :: analyze_block new_env new_ua new_block
;;

let analyze_func env ua = function
  | Syntax.Func f -> Func (f.func, f.args, analyze_block env ua f.code)
;;

let rec analyze_prog env ua = function
  | [] -> []
  | fn :: suite -> analyze_func env ua fn :: analyze_prog env ua suite
;;

let analyze parsed = analyze_prog _types_ [] parsed