Commit | Line | Data |
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523e2b06 SK |
1 | module List = ListLabels |
2 | ||
155ee327 | 3 | module A = Tiger_absyn |
e6e82c08 | 4 | module Dag = Tiger_dag |
155ee327 SK |
5 | module Env = Tiger_env |
6 | module E = Tiger_error | |
21d0f050 | 7 | module Escape = Tiger_semant_escape |
e6e82c08 SK |
8 | module Pos = Tiger_position |
9 | module Sym = Tiger_symbol | |
155ee327 SK |
10 | module Translate = Tiger_translate |
11 | module Type = Tiger_env_type | |
12 | module Value = Tiger_env_value | |
13 | ||
14 | (* The only reason for having this seemingly-superfluous inner module is to | |
15 | * have this nice signature as a summary of what each function does. *) | |
16 | module Semant : sig | |
17 | type expty = | |
18 | { exp : Translate.exp | |
19 | ; ty : Type.t | |
20 | } | |
21 | ||
22 | (* Violating normal naming convention just to make it easier to follow | |
23 | * Appel's | |
24 | *) | |
25 | val transExp : env:Env.t -> A.exp -> expty | |
862e5c05 SK |
26 | |
27 | (* transVar does not seem to be needed, as trvar handles all our cases. | |
28 | * Am I wrong? | |
29 | * | |
30 | * val transVar : env:Env.t -> A.var -> expty | |
31 | * | |
32 | *) | |
155ee327 SK |
33 | end = struct |
34 | type expty = | |
35 | { exp : Translate.exp | |
36 | ; ty : Type.t | |
37 | } | |
38 | ||
cbb4ffb6 SK |
39 | let rec actual_ty ty ~pos = |
40 | match ty with | |
41 | | Type.Name (name, ty_opt_ref) -> | |
42 | (match !ty_opt_ref with | |
43 | | None -> | |
44 | E.raise (E.Unknown_type {ty_id=name; pos}) | |
45 | | Some ty -> | |
46 | actual_ty ty ~pos | |
47 | ) | |
48 | | Type.Unit | |
49 | | Type.Nil | |
50 | | Type.Int | |
51 | | Type.String | |
52 | | Type.Record _ | |
53 | | Type.Array _ -> | |
54 | ty | |
55 | ||
523e2b06 SK |
56 | let return ty = {exp = (); ty} |
57 | let return_unit = return Type.Unit | |
58 | let return_nil = return Type.Nil | |
59 | let return_int = return Type.Int | |
60 | let return_string = return Type.String | |
155ee327 | 61 | |
523e2b06 SK |
62 | let env_get_typ ~sym ~env ~pos : Type.t = |
63 | match Env.get_typ env sym with | |
64 | | Some ty -> ty | |
65 | | None -> E.raise (E.Unknown_type {ty_id=sym; pos}) | |
66 | ||
cbb4ffb6 SK |
67 | let env_get_typ_actual ~sym ~env ~pos : Type.t = |
68 | actual_ty (env_get_typ ~sym ~env ~pos) ~pos | |
69 | ||
523e2b06 SK |
70 | let env_get_val ~sym ~env ~pos : Value.t = |
71 | match Env.get_val env sym with | |
72 | | Some ty -> ty | |
73 | | None -> E.raise (E.Unknown_id {id=sym; pos}) | |
74 | ||
75 | let check_same {exp=_; ty=ty_left} {exp=_; ty=ty_right} ~pos : unit = | |
76 | if Type.is_equal ty_left ty_right then | |
77 | () | |
78 | else | |
79 | E.raise (E.Wrong_type {expected=ty_left; given=ty_right; pos}) | |
80 | ||
81 | let check_int expty ~pos : unit = | |
cbb4ffb6 | 82 | check_same return_int expty ~pos |
978cb41c | 83 | |
e6e82c08 SK |
84 | let paths_of_typedecs typedecs : (Sym.t * Sym.t * Pos.t) list list = |
85 | let (path, paths) = | |
86 | List.fold_left typedecs ~init:([], []) ~f:( | |
87 | fun (path, paths) (A.TypeDec {name=child; ty; pos}) -> | |
88 | match ty with | |
89 | | A.NameTy {symbol=parent; _} -> | |
90 | (((parent, child, pos) :: path), paths) | |
91 | | A.RecordTy _ | |
92 | | A.ArrayTy _ -> | |
93 | ([], path :: paths) | |
94 | ) | |
95 | in | |
96 | List.map (path :: paths) ~f:List.rev | |
97 | ||
98 | let check_cycles (typedecs : A.typedec list) : unit = | |
99 | let non_empty_paths = | |
100 | List.filter | |
101 | (paths_of_typedecs typedecs) | |
102 | ~f:(function [] -> false | _ -> true) | |
103 | in | |
104 | List.iter non_empty_paths ~f:( | |
105 | fun path -> | |
106 | match Dag.of_list (List.map path ~f:(fun (p, c, _) -> (p, c))) with | |
107 | | Ok _ -> | |
108 | () | |
109 | | Error `Cycle -> | |
110 | let (_, from_id, from_pos) = List.hd path in | |
111 | let (_, to_id, to_pos) = List.hd (List.rev path) in | |
112 | E.raise (E.Cycle_in_type_decs {from_id; from_pos; to_id; to_pos}) | |
113 | ) | |
114 | ||
523e2b06 SK |
115 | let rec transExp ~env exp = |
116 | let rec trexp exp = | |
117 | (match exp with | |
118 | | A.NilExp -> | |
119 | return_nil | |
120 | | A.IntExp _ -> | |
121 | return_int | |
122 | | A.StringExp {string=_; _} -> | |
123 | return_string | |
978cb41c SK |
124 | | A.CallExp {func; args; pos} -> |
125 | (match env_get_val ~sym:func ~env ~pos with | |
126 | | Value.Fun {formals; result} -> | |
54e838f4 SK |
127 | let expected = List.length formals in |
128 | let given = List.length args in | |
129 | if given = expected then | |
130 | begin | |
131 | List.iter2 formals args ~f:(fun ty_expected exp_given -> | |
132 | check_same | |
133 | (return (actual_ty ~pos ty_expected)) | |
134 | (trexp exp_given) | |
135 | ~pos; | |
136 | ); | |
137 | return (actual_ty ~pos result) | |
138 | end | |
139 | else | |
140 | E.raise (E.Wrong_number_of_args {func; expected; given; pos}) | |
978cb41c SK |
141 | | Value.Var _ -> |
142 | E.raise (E.Id_not_a_function {id=func; pos}) | |
143 | ) | |
523e2b06 SK |
144 | | A.OpExp {oper; left; right; pos} -> |
145 | trop oper ~left ~right ~pos | |
0ed7a07c | 146 | | A.RecordExp {fields=field_exps; typ; pos} -> |
cbb4ffb6 | 147 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
0ed7a07c SK |
148 | Type.if_record |
149 | ty | |
150 | ~f:(fun field_tys -> | |
151 | List.iter field_exps ~f:(fun (field, exp, pos) -> | |
152 | (match List.assoc_opt field field_tys with | |
153 | | Some field_ty -> | |
cbb4ffb6 | 154 | check_same (return (actual_ty ~pos field_ty)) (trexp exp) ~pos |
0ed7a07c SK |
155 | | None -> |
156 | E.raise | |
157 | (E.No_such_field_in_record {field; record=ty; pos}) | |
158 | ) | |
159 | ) | |
160 | ) | |
161 | ~otherwise:(fun () -> | |
162 | E.raise (E.Wrong_type_used_as_record {ty_id=typ; ty; pos}) | |
163 | ); | |
cbb4ffb6 | 164 | return (actual_ty ~pos ty) |
9d8471b2 | 165 | | A.SeqExp [] -> |
523e2b06 | 166 | return_unit |
9d8471b2 SK |
167 | | A.SeqExp exps -> |
168 | let last xs = | |
169 | xs | |
170 | |> List.rev (* Yes, redundant, but clean-looking ;-P *) | |
171 | |> List.hd (* Empty is matched in above SeqExp match case *) | |
172 | in | |
173 | exps | |
cbb4ffb6 | 174 | |> List.map ~f:(fun (exp, _) -> trexp exp) |
9d8471b2 | 175 | |> last |
523e2b06 SK |
176 | | A.AssignExp {var; exp; pos} -> |
177 | check_same (trvar var) (trexp exp) ~pos; | |
178 | (* TODO: Add var->exp to val env? *) | |
179 | return_unit | |
180 | | A.IfExp {test; then'; else'; pos} -> | |
181 | (* test : must be int, because we have no bool *) | |
182 | (* then : must equal else *) | |
183 | (* else : must equal then or be None *) | |
184 | check_int (trexp test) ~pos; | |
185 | (match (trexp then', else') with | |
186 | | expty_then, None -> | |
187 | expty_then | |
188 | | expty_then, Some else' -> | |
189 | let expty_else = trexp else' in | |
190 | check_same expty_then expty_else ~pos; | |
191 | expty_then | |
192 | ) | |
193 | | A.WhileExp {test; body; pos} -> | |
194 | (* test : must be int, because we have no bool *) | |
195 | check_int (trexp test) ~pos; | |
35dccbd3 SK |
196 | let (loop, env) = Env.loop_begin env in |
197 | (* Only care if an error is raised *) | |
198 | ignore (transExp ~env body); | |
199 | ignore (Env.loop_end env loop); | |
523e2b06 SK |
200 | return_unit |
201 | | A.ForExp {var; lo; hi; body; pos; escape=_} -> | |
202 | check_int (trexp lo) ~pos; | |
203 | check_int (trexp hi) ~pos; | |
35dccbd3 | 204 | let (loop, env) = Env.loop_begin env in |
85e08b69 | 205 | let env = Env.set_val env var (Value.Var {ty = Type.Int}) in |
35dccbd3 | 206 | (* Only care if an error is raised *) |
85e08b69 | 207 | ignore (transExp ~env body); |
35dccbd3 | 208 | ignore (Env.loop_end env loop); |
523e2b06 | 209 | return_unit |
35dccbd3 SK |
210 | | A.BreakExp pos -> |
211 | (match Env.loop_current env with | |
212 | | Some _ -> () | |
213 | | None -> E.raise (E.Break_outside_loop pos) | |
214 | ); | |
523e2b06 | 215 | return_unit |
8744eb3a SK |
216 | | A.LetExp {decs; body; pos=_} -> |
217 | (* (1) decs augment env *) | |
218 | (* (2) body checked against the new env *) | |
219 | let env = | |
220 | List.fold_left decs ~init:env ~f:(fun env dec -> transDec dec ~env) | |
221 | in | |
222 | transExp body ~env | |
4c550cd5 SK |
223 | | A.ArrayExp {typ; size; init; pos} -> |
224 | check_int (trexp size) ~pos; | |
cbb4ffb6 | 225 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
4c550cd5 SK |
226 | Type.if_array |
227 | ty | |
228 | ~f:(fun ty_elements -> | |
cbb4ffb6 | 229 | check_same (return (actual_ty ~pos ty_elements)) (trexp init) ~pos |
4c550cd5 SK |
230 | ) |
231 | ~otherwise:(fun () -> | |
232 | E.raise (E.Wrong_type_used_as_array {ty_id=typ; ty; pos}) | |
233 | ); | |
cbb4ffb6 | 234 | return (actual_ty ~pos ty) |
523e2b06 SK |
235 | | A.VarExp var -> |
236 | trvar var | |
237 | ) | |
238 | and trvar = | |
239 | (function | |
240 | | A.SimpleVar {symbol=sym; pos} -> | |
241 | (match env_get_val ~sym ~env ~pos with | |
242 | | Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos}) | |
cbb4ffb6 | 243 | | Value.Var {ty} -> return (actual_ty ~pos ty) |
523e2b06 SK |
244 | ) |
245 | | A.FieldVar {var; symbol; pos} -> | |
246 | let {exp=_; ty} = trvar var in | |
247 | Type.if_record | |
248 | ty | |
249 | ~f:(fun fields -> | |
250 | (match List.assoc_opt symbol fields with | |
251 | | None -> | |
252 | E.raise | |
253 | (E.No_such_field_in_record {field=symbol; record=ty; pos}) | |
254 | | Some ty -> | |
cbb4ffb6 | 255 | return (actual_ty ~pos ty) |
523e2b06 SK |
256 | ) |
257 | ) | |
258 | ~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos})) | |
161a300d SK |
259 | | A.SubscriptVar {var; exp; pos} -> |
260 | let {exp=_; ty} = trvar var in | |
261 | check_int (trexp exp) ~pos; | |
262 | Type.if_array | |
263 | ty | |
cbb4ffb6 | 264 | ~f:(fun ty_elements -> return (actual_ty ~pos ty_elements)) |
161a300d | 265 | ~otherwise:(fun () -> E.raise (E.Exp_not_an_array {ty; pos})) |
523e2b06 SK |
266 | ) |
267 | and trop oper ~left ~right ~pos = | |
cbb4ffb6 | 268 | (* TODO: Refactor trop - all opers return bool/int *) |
523e2b06 SK |
269 | let expty_left = trexp left in |
270 | let expty_right = trexp right in | |
271 | check_same expty_left expty_right ~pos; | |
272 | let {exp=_; ty} = expty_left in | |
273 | let module T = Type in | |
274 | (match oper with | |
275 | (* Arithmetic: int *) | |
276 | | A.PlusOp | |
277 | | A.MinusOp | |
278 | | A.TimesOp | |
279 | | A.DivideOp -> | |
280 | check_int expty_left ~pos; | |
281 | return_int | |
282 | (* Equality: int, string, array, record *) | |
283 | | A.EqOp | |
284 | | A.NeqOp -> | |
285 | if (T.is_int ty) | |
286 | || (T.is_string ty) | |
287 | || (T.is_array ty) | |
288 | || (T.is_record ty) | |
289 | then | |
cbb4ffb6 | 290 | return_int (* Because we have no bool type *) |
523e2b06 SK |
291 | else |
292 | E.raise (E.Invalid_operand_type | |
293 | { oper | |
294 | ; valid = ["int"; "string"; "array"; "record"] | |
295 | ; given = ty | |
296 | ; pos | |
297 | }) | |
298 | (* Order: int, string *) | |
299 | | A.LtOp | |
300 | | A.LeOp | |
301 | | A.GtOp | |
302 | | A.GeOp -> | |
303 | if (T.is_int ty) | |
304 | || (T.is_string ty) | |
305 | then | |
cbb4ffb6 | 306 | return_int (* Because we have no bool type *) |
523e2b06 SK |
307 | else |
308 | E.raise (E.Invalid_operand_type | |
309 | { oper | |
310 | ; valid = ["int"; "string"] | |
311 | ; given = ty | |
312 | ; pos | |
313 | }) | |
314 | ) | |
315 | in | |
316 | trexp exp | |
862e5c05 | 317 | and transDec ~(env : Env.t) (dec : A.dec) : Env.t = |
8744eb3a SK |
318 | (match dec with |
319 | | A.VarDec {name; typ=typ_opt; init; pos=pos_outter; escape=_} -> | |
320 | let ty = | |
321 | (match (typ_opt, transExp ~env init) with | |
322 | | None, {ty; exp=()} -> | |
323 | ty | |
324 | | Some (sym, pos_inner), expty_init -> | |
cbb4ffb6 SK |
325 | let ty = env_get_typ_actual ~sym ~env ~pos:pos_inner in |
326 | check_same (return ty) expty_init ~pos:pos_outter; | |
8744eb3a SK |
327 | ty |
328 | ) | |
329 | in | |
330 | Env.set_val env name (Value.Var {ty}) | |
0324a942 | 331 | | A.TypeDecs typedecs -> |
e6e82c08 | 332 | check_cycles typedecs; |
cbb4ffb6 SK |
333 | let env = |
334 | List.fold_left typedecs ~init:env ~f:( | |
335 | fun env (A.TypeDec {name; ty=_; pos=_}) -> | |
336 | Env.set_typ env name (Type.Name (name, ref None)) | |
337 | ) | |
338 | in | |
a131e30c SK |
339 | List.iter typedecs ~f:(fun (A.TypeDec {name=ty_name; ty=ty_exp; pos}) -> |
340 | let ty = transTy ~env ~ty_name ~ty_exp in | |
341 | (match env_get_typ ~sym:ty_name ~env ~pos with | |
9340b0e3 | 342 | | Type.Name (_, ty_opt_ref) -> |
cbb4ffb6 SK |
343 | ty_opt_ref := Some ty |
344 | | Type.Unit | |
345 | | Type.Nil | |
346 | | Type.Int | |
347 | | Type.String | |
348 | | Type.Record _ | |
349 | | Type.Array _ -> | |
350 | () | |
351 | ) | |
352 | ); | |
353 | env | |
76c771a7 | 354 | | A.FunDecs fundecs -> |
a284f5c2 SK |
355 | let env_with_fun_heads_only = |
356 | List.fold_left fundecs ~init:env ~f:( | |
357 | fun env (A.FunDec {name; params; result; body=_; pos=_}) -> | |
358 | let formals = | |
359 | List.map params ~f:( | |
360 | fun (A.Field {name=_; typ; pos; escape=_}) -> | |
361 | env_get_typ_actual ~env ~sym:typ ~pos | |
362 | ) | |
363 | in | |
364 | let result = | |
365 | match result with | |
366 | | Some (s, p) -> env_get_typ_actual ~sym:s ~env ~pos:p | |
367 | | None -> Type.Unit | |
368 | in | |
369 | Env.set_val env name (Value.Fun {formals; result}) | |
370 | ) | |
371 | in | |
372 | List.iter fundecs ~f:( | |
373 | fun (A.FunDec {name=_; params; result=_; body; pos=_}) -> | |
374 | let env_with_fun_heads_and_local_vars = | |
375 | List.fold_left params ~init:env_with_fun_heads_only ~f:( | |
376 | fun env (A.Field {name=var_name; escape=_; typ; pos}) -> | |
377 | let var_ty = env_get_typ_actual ~env ~sym:typ ~pos in | |
378 | Env.set_val env var_name (Value.Var {ty = var_ty}) | |
76c771a7 SK |
379 | ) |
380 | in | |
a284f5c2 SK |
381 | (* we only care if an exception is raised *) |
382 | ignore (transExp ~env:env_with_fun_heads_and_local_vars body); | |
383 | ); | |
384 | env_with_fun_heads_only | |
8744eb3a | 385 | ) |
a131e30c | 386 | and transTy ~(env : Env.t) ~ty_name ~(ty_exp : A.ty) : Type.t = |
cbb4ffb6 | 387 | (match ty_exp with |
0324a942 SK |
388 | | A.NameTy {symbol=sym; pos} -> |
389 | env_get_typ ~sym ~env ~pos | |
390 | | A.RecordTy fields -> | |
391 | let fields = | |
392 | List.map fields ~f:(fun (A.Field {name; escape=_; typ; pos}) -> | |
393 | let ty = env_get_typ ~sym:typ ~env ~pos in | |
394 | (name, ty) | |
395 | ) | |
396 | in | |
a131e30c | 397 | Type.new_record ~name:ty_name ~fields |
0324a942 SK |
398 | | A.ArrayTy {symbol=sym; pos} -> |
399 | let element_ty = env_get_typ ~sym ~env ~pos in | |
a131e30c | 400 | Type.new_array ~name:ty_name ~ty:element_ty |
0324a942 | 401 | ) |
155ee327 SK |
402 | end |
403 | ||
8744eb3a SK |
404 | open Semant |
405 | ||
155ee327 | 406 | let transProg absyn = |
21d0f050 | 407 | Escape.find absyn; |
155ee327 SK |
408 | let {exp = _; ty = _} = transExp absyn ~env:Env.base in |
409 | () |