X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=compiler%2Fsrc%2Flib%2Ftiger%2Ftiger_semant.ml;h=25eb2ce44462c2d54a2118113293b333198ed980;hb=21d0f0503ea169988685a4f39d0e32b2b097dae6;hp=21816959a1ab402b4f736c3d27cf15f73f06d5e6;hpb=9340b0e333dd6acb5b18f68d1bf3eadad8401fa5;p=tiger.ml.git diff --git a/compiler/src/lib/tiger/tiger_semant.ml b/compiler/src/lib/tiger/tiger_semant.ml index 2181695..25eb2ce 100644 --- a/compiler/src/lib/tiger/tiger_semant.ml +++ b/compiler/src/lib/tiger/tiger_semant.ml @@ -1,8 +1,12 @@ module List = ListLabels module A = Tiger_absyn +module Dag = Tiger_dag module Env = Tiger_env module E = Tiger_error +module Escape = Tiger_semant_escape +module Pos = Tiger_position +module Sym = Tiger_symbol module Translate = Tiger_translate module Type = Tiger_env_type module Value = Tiger_env_value @@ -77,6 +81,37 @@ end = struct let check_int expty ~pos : unit = check_same return_int expty ~pos + let paths_of_typedecs typedecs : (Sym.t * Sym.t * Pos.t) list list = + let (path, paths) = + List.fold_left typedecs ~init:([], []) ~f:( + fun (path, paths) (A.TypeDec {name=child; ty; pos}) -> + match ty with + | A.NameTy {symbol=parent; _} -> + (((parent, child, pos) :: path), paths) + | A.RecordTy _ + | A.ArrayTy _ -> + ([], path :: paths) + ) + in + List.map (path :: paths) ~f:List.rev + + let check_cycles (typedecs : A.typedec list) : unit = + let non_empty_paths = + List.filter + (paths_of_typedecs typedecs) + ~f:(function [] -> false | _ -> true) + in + List.iter non_empty_paths ~f:( + fun path -> + match Dag.of_list (List.map path ~f:(fun (p, c, _) -> (p, c))) with + | Ok _ -> + () + | Error `Cycle -> + let (_, from_id, from_pos) = List.hd path in + let (_, to_id, to_pos) = List.hd (List.rev path) in + E.raise (E.Cycle_in_type_decs {from_id; from_pos; to_id; to_pos}) + ) + let rec transExp ~env exp = let rec trexp exp = (match exp with @@ -158,16 +193,25 @@ end = struct | A.WhileExp {test; body; pos} -> (* test : must be int, because we have no bool *) check_int (trexp test) ~pos; - ignore (trexp body); (* Only care if a type-error is raised *) + let (loop, env) = Env.loop_begin env in + (* Only care if an error is raised *) + ignore (transExp ~env body); + ignore (Env.loop_end env loop); return_unit | A.ForExp {var; lo; hi; body; pos; escape=_} -> check_int (trexp lo) ~pos; check_int (trexp hi) ~pos; - (* Only care if a type-error is raised *) + let (loop, env) = Env.loop_begin env in let env = Env.set_val env var (Value.Var {ty = Type.Int}) in + (* Only care if an error is raised *) ignore (transExp ~env body); + ignore (Env.loop_end env loop); return_unit - | A.BreakExp _ -> + | A.BreakExp pos -> + (match Env.loop_current env with + | Some _ -> () + | None -> E.raise (E.Break_outside_loop pos) + ); return_unit | A.LetExp {decs; body; pos=_} -> (* (1) decs augment env *) @@ -285,15 +329,16 @@ end = struct in Env.set_val env name (Value.Var {ty}) | A.TypeDecs typedecs -> + check_cycles typedecs; let env = List.fold_left typedecs ~init:env ~f:( fun env (A.TypeDec {name; ty=_; pos=_}) -> Env.set_typ env name (Type.Name (name, ref None)) ) in - List.iter typedecs ~f:(fun (A.TypeDec {name; ty=ty_exp; pos}) -> - let ty = transTy ~env ty_exp in - (match env_get_typ ~sym:name ~env ~pos with + List.iter typedecs ~f:(fun (A.TypeDec {name=ty_name; ty=ty_exp; pos}) -> + let ty = transTy ~env ~ty_name ~ty_exp in + (match env_get_typ ~sym:ty_name ~env ~pos with | Type.Name (_, ty_opt_ref) -> ty_opt_ref := Some ty | Type.Unit @@ -307,30 +352,38 @@ end = struct ); env | A.FunDecs fundecs -> - List.fold_left fundecs ~init:env ~f:( - fun env (A.FunDec {name; params; result; body; pos=_}) -> - let (env_for_body, formals_in_reverse_order) = - List.fold_left params ~init:(env, []) ~f:( - fun (env, formals) (A.Field {name; escape=_; typ; pos}) -> - let ty = env_get_typ_actual ~env ~sym:typ ~pos in - let env = Env.set_val env name (Value.Var {ty}) in - (env, ty :: formals) + let env_with_fun_heads_only = + List.fold_left fundecs ~init:env ~f:( + fun env (A.FunDec {name; params; result; body=_; pos=_}) -> + let formals = + List.map params ~f:( + fun (A.Field {name=_; typ; pos; escape=_}) -> + env_get_typ_actual ~env ~sym:typ ~pos + ) + in + let result = + match result with + | Some (s, p) -> env_get_typ_actual ~sym:s ~env ~pos:p + | None -> Type.Unit + in + Env.set_val env name (Value.Fun {formals; result}) + ) + in + List.iter fundecs ~f:( + fun (A.FunDec {name=_; params; result=_; body; pos=_}) -> + let env_with_fun_heads_and_local_vars = + List.fold_left params ~init:env_with_fun_heads_only ~f:( + fun env (A.Field {name=var_name; escape=_; typ; pos}) -> + let var_ty = env_get_typ_actual ~env ~sym:typ ~pos in + Env.set_val env var_name (Value.Var {ty = var_ty}) ) in - (* ignore because we only care if an exception is raised *) - ignore (transExp ~env:env_for_body body); - let formals = List.rev formals_in_reverse_order in - let result = - match result with - | None -> - Type.Unit - | Some (sym, pos) -> - env_get_typ_actual ~sym ~env ~pos - in - Env.set_val env name (Value.Fun {formals; result}) - ) + (* we only care if an exception is raised *) + ignore (transExp ~env:env_with_fun_heads_and_local_vars body); + ); + env_with_fun_heads_only ) - and transTy ~(env : Env.t) (ty_exp : A.ty) : Type.t = + and transTy ~(env : Env.t) ~ty_name ~(ty_exp : A.ty) : Type.t = (match ty_exp with | A.NameTy {symbol=sym; pos} -> env_get_typ ~sym ~env ~pos @@ -341,15 +394,16 @@ end = struct (name, ty) ) in - Type.new_record fields + Type.new_record ~name:ty_name ~fields | A.ArrayTy {symbol=sym; pos} -> let element_ty = env_get_typ ~sym ~env ~pos in - Type.new_array element_ty + Type.new_array ~name:ty_name ~ty:element_ty ) end open Semant let transProg absyn = + Escape.find absyn; let {exp = _; ty = _} = transExp absyn ~env:Env.base in ()