parsing_c/cpp_token_c.ml

   1 open Common
   2
   3 module TH = Token_helpers
   4
   5 open Parser_c
   6 open Token_views_c
   7
   8 (*****************************************************************************)
   9 (* Prelude *)
  10 (*****************************************************************************)
  11
  12 (* cpp functions working at the token level. Cf cpp_ast_c for cpp functions
  13  * working at the AST level (which is very unusual but makes sense in
  14  * the coccinelle context for instance).
  15  *
  16  * Note that as I use a single lexer  to work both at the C and cpp level
  17  * there are some inconveniencies.
  18  * For instance 'for' is a valid name for a macro parameter and macro
  19  * body, but is interpreted in a special way by our single lexer, and
  20  * so at some places where I expect a TIdent I need also to
  21  * handle special cases and accept Tfor, Tif, etc at those places.
  22  *
  23  * There are multiple issues related to those keywords incorrect tokens.
  24  * Those keywords can be:
  25  *   - (1) in the name of the macro as  in  #define inline
  26  *   - (2) in a parameter of the macro as in #define foo(char)   char x;
  27  *   - (3) in an argument to a macro call as in   IDENT(if);
  28  * Case 1 is easy to fix in define_ident.
  29  * Case 2 is easy to fix in define_parse where detect such toks in
  30  * the parameter and then replace their occurence in the body in a Tident.
  31  * Case 3 is only an issue when the expanded token is not really use
  32  * as usual but use for instance in concatenation as in  a ## if
  33  * when expanded. In the case the grammar this time will not be happy
  34  * so this is also easy to fix in cpp_engine.
  35  *
  36  *)
  37
  38 (*****************************************************************************)
  39 (* Wrappers *)
  40 (*****************************************************************************)
  41 let pr2, pr2_once = Common.mk_pr2_wrappers Flag_parsing_c.verbose_parsing
  42
  43 (*****************************************************************************)
  44 (* Types *)
  45 (*****************************************************************************)
  46
  47 (* ------------------------------------------------------------------------- *)
  48 (* mimic standard.h *)
  49 (* ------------------------------------------------------------------------- *)
  50
  51 type define_def = string * define_param * define_body
  52  and define_param =
  53    | NoParam
  54    | Params of define_arg list
  55  and define_arg = FixedArg of string | VariadicArg of string
  56  and define_body =
  57    | DefineBody of Parser_c.token list
  58    | DefineHint of parsinghack_hint
  59
  60    and parsinghack_hint =
  61      | HintIterator
  62      | HintDeclarator
  63      | HintMacroString
  64      | HintMacroStatement
  65      | HintAttribute
  66      | HintMacroIdentBuilder
  67
  68
  69 (*****************************************************************************)
  70 (* Parsing and helpers of hints  *)
  71 (*****************************************************************************)
  72
  73 (* cf also data/test.h *)
  74 let assoc_hint_string = [
  75   "YACFE_ITERATOR"   , HintIterator;
  76   "YACFE_DECLARATOR" , HintDeclarator;
  77   "YACFE_STRING"     , HintMacroString;
  78   "YACFE_STATEMENT"  , HintMacroStatement;
  79   "YACFE_ATTRIBUTE"  , HintAttribute;
  80   "YACFE_IDENT_BUILDER"  , HintMacroIdentBuilder;
  81
  82   "MACROSTATEMENT"   , HintMacroStatement; (* backward compatibility *)
  83 ]
  84
  85
  86 let (parsinghack_hint_of_string: string -> parsinghack_hint option) = fun s ->
  87   Common.assoc_option s assoc_hint_string
  88 let (string_of_parsinghack_hint: parsinghack_hint -> string) = fun hint ->
  89   let assoc' = assoc_hint_string +> List.map (fun (a,b) -> (b,a) ) in
  90   Common.assoc hint assoc'
  91
  92
  93
  94 let (is_parsinghack_hint: string -> bool) = fun s ->
  95   parsinghack_hint_of_string s <> None
  96
  97 let (token_from_parsinghack_hint:
  98      (string * Ast_c.info) -> parsinghack_hint -> Parser_c.token) =
  99  fun (s,ii) hint ->
 100    match hint with
 101    | HintIterator ->
 102        Parser_c.TMacroIterator (s, ii)
 103    | HintDeclarator ->
 104        Parser_c.TMacroDecl (s, ii)
 105    | HintMacroString ->
 106        Parser_c.TMacroString (s, ii)
 107    | HintMacroStatement ->
 108        Parser_c.TMacroStmt (s, ii)
 109    | HintAttribute ->
 110        Parser_c.TMacroAttr (s, ii)
 111    | HintMacroIdentBuilder ->
 112        Parser_c.TMacroIdentBuilder (s, ii)
 113
 114
 115 (* used in extract_macros for example *)
 116 let string_of_define_def (s, params, body) =
 117
 118   let s1 =
 119     match params with
 120     | NoParam ->
 121         spf "#define %s " s
 122     | Params xs ->
 123         let xs = List.map (function FixedArg s -> s | VariadicArg s -> s) xs in
 124         spf "#define %s(%s) " s (Common.join "," xs)
 125   in
 126   let s2 =
 127     match body with
 128     | DefineHint hint ->
 129         string_of_parsinghack_hint hint
 130     | DefineBody xs ->
 131         Common.join " " (xs +> List.map Token_helpers.str_of_tok)
 132   in
 133   s1 ^ s2
 134
 135
 136 (*****************************************************************************)
 137 (* Expansion helpers *)
 138 (*****************************************************************************)
 139
 140 (* In some cases we can have macros like IDENT(if) that expands to some
 141  * 'int xxx_if(void)', but as the lexer will currently generate a Tif for
 142  * the expanded code, that may not be accepted as a token after a ##
 143  * in the grammar. Hence this function to remap some tokens. This is because
 144  * we should not use a single lexer for both working at the C level and
 145  * cpp level.
 146  *
 147  * update: it can also rename some TypedefIdent into TIdent, possibly
 148  * because of bad interaction with add_typedef_root in parsing_hacks.
 149  *)
 150 let rec remap_keyword_tokens xs =
 151   match xs with
 152   | [] -> []
 153   | [x] -> [x]
 154   | x::y::xs ->
 155       (match x, y with
 156       | Parser_c.TCppConcatOp _, Parser_c.TIdent _ ->
 157           x::y::remap_keyword_tokens xs
 158       | Parser_c.TIdent _, Parser_c.TCppConcatOp _ ->
 159           x::y::remap_keyword_tokens xs
 160
 161       | Parser_c.TCppConcatOp (i1),   y ->
 162           let s = TH.str_of_tok y in
 163           let ii = TH.info_of_tok y in
 164           if s ==~ Common.regexp_alpha
 165           then begin
 166             pr2 (spf "remapping: %s to an ident in expanded code" s);
 167             x::(Parser_c.TIdent (s, ii))::remap_keyword_tokens xs
 168           end
 169           else
 170             x::y::remap_keyword_tokens xs
 171
 172       | x, Parser_c.TCppConcatOp (i1) ->
 173           let s = TH.str_of_tok x in
 174           let ii = TH.info_of_tok x in
 175           if s ==~ Common.regexp_alpha
 176           then begin
 177             pr2 (spf "remapping: %s to an ident in expanded code" s);
 178             (Parser_c.TIdent (s, ii))::remap_keyword_tokens (y::xs)
 179           end
 180           else
 181             x::y::remap_keyword_tokens xs
 182
 183       | _, _ ->
 184           x::remap_keyword_tokens (y::xs)
 185       )
 186
 187
 188 (* works with agglomerate_concat_op_ident below *)
 189 let rec get_ident_in_concat_op xs =
 190   match xs with
 191   | [] ->
 192       pr2 "weird: ident after ## operator not found";
 193       "", []
 194   | [x] ->
 195       (match x with
 196       | Parser_c.TIdent (s, i1) -> s, []
 197       | _ ->
 198           pr2 "weird: ident after ## operator not found";
 199           "", [x]
 200       )
 201   | x::y::xs ->
 202       (match x, y with
 203       | Parser_c.TIdent (s,i1), Parser_c.TCppConcatOp (i2) ->
 204           let (s2, rest) = get_ident_in_concat_op xs in
 205           s ^ s2, rest
 206       | Parser_c.TIdent (s, i1), _ ->
 207           s, (y::xs)
 208       | _ ->
 209           pr2 "weird: ident after ## operator not found";
 210           "", x::y::xs
 211       )
 212
 213 (* must be run after the expansion has been done for the parameter so
 214  * that all idents are actually ident, not macro parameter names.
 215  *)
 216 let rec agglomerate_concat_op_ident xs =
 217   match xs with
 218   | [] -> []
 219   | [x] -> [x]
 220   | x::y::xs ->
 221       (* can we have ## id, and so ## as first token ? yes
 222        * but the semantic is different as it represents variadic
 223        * names so this must be handled elsewhere.
 224        *)
 225       (match x, y with
 226       | Parser_c.TIdent (s,i1), Parser_c.TCppConcatOp (i2) ->
 227           let (all_str_ident, rest_toks) =
 228             get_ident_in_concat_op xs
 229           in
 230           let new_s = s ^ all_str_ident in
 231           let i1' = Ast_c.rewrap_str new_s i1 in
 232           Parser_c.TIdent (new_s, i1')::agglomerate_concat_op_ident rest_toks
 233       | Parser_c.TCppConcatOp _, _ ->
 234           pr2 "weird, ## alone";
 235           x::agglomerate_concat_op_ident (y::xs)
 236       | _ ->
 237           x::agglomerate_concat_op_ident (y::xs)
 238
 239       )
 240
 241
 242
 243 (* To expand the parameter of the macro. The env corresponds to the actual
 244  * code that is binded to the parameters of the macro.
 245  * Recurse ? fixpoint ? the expansion may also contain macro.
 246  * Or to macro expansion in a strict manner, that is process first
 247  * the parameters, expands macro in params, and then process enclosing
 248  * macro call.
 249  *
 250  * note: do the concatenation job of a##b here ?
 251  * normally this should be done in the grammar. Here just expand
 252  * tokens. The only thing we handle here is we may have to remap
 253  * some tokens.
 254  *
 255  * todo: handle stringification here ? if #n
 256  *
 257  * todo? but could parsing_hacks then pass over the remapped tokens,
 258  * for instance transform some of the back into some TypedefIdent
 259  * so cpp_engine may be fooled?
 260  *)
 261 let rec (cpp_engine:
 262           ?evaluate_concatop:bool ->
 263           (string , Parser_c.token list) assoc ->
 264           Parser_c.token list -> Parser_c.token list) =
 265  fun ?(evaluate_concatop=true) env xs ->
 266   xs +> List.map (fun tok ->
 267     (* expand only TIdent ? no cos the parameter of the macro
 268      * can actually be some 'register' so may have to look for
 269      * any tokens candidates for the expansion.
 270      * Only subtelity is maybe dont expand the TDefineIdent.
 271      *
 272      * update: in fact now the caller (define_parse) will have done
 273      * the job right and already replaced the macro parameter with a TIdent.
 274      *)
 275     match tok with
 276     | TIdent (s,i1) when List.mem_assoc s env ->
 277         Common.assoc s env
 278     | x -> [x]
 279   )
 280   +> List.flatten
 281   +> remap_keyword_tokens
 282   +> (fun xs ->
 283        if evaluate_concatop
 284        then agglomerate_concat_op_ident xs
 285        else xs
 286   )
 287
 288
 289
 290 (* ------------------------------------------------------------------------- *)
 291 (* apply macro, using standard.h or other defs *)
 292 (* ------------------------------------------------------------------------- *)
 293
 294 (* Thanks to this function many stuff are not anymore hardcoded in ocaml code.
 295  * At some point there were hardcoded in a standard.h file but now I
 296  * can even generate them on the fly on demand when there is actually
 297  * a parsing problem.
 298  *
 299  * No need to take care to not substitute the macro name itself
 300  * that occurs in the macro definition because the macro name is
 301  * after fix_token_define a TDefineIdent, no more a TIdent.
 302  *)
 303
 304 let rec apply_macro_defs
 305  ~msg_apply_known_macro
 306  ~msg_apply_known_macro_hint
 307  ?evaluate_concatop
 308  ?(inplace_when_single=true)
 309  defs xs =
 310
 311  let rec apply_macro_defs xs =
 312   match xs with
 313   | [] -> ()
 314
 315   (* old: "but could do more, could reuse same original token
 316    * so that have in the Ast a Dbg, not a MACROSTATEMENT"
 317    *
 318    *   | PToken ({tok = TIdent (s,i1)} as id)::xs
 319    *     when s = "MACROSTATEMENT" ->
 320    *
 321    *     msg_macro_statement_hint s;
 322    *     id.tok <- TMacroStmt(TH.info_of_tok id.tok);
 323    *     find_macro_paren xs
 324    *
 325    *  let msg_macro_statement_hint s =
 326    *    incr Stat.nMacroHint;
 327    *   ()
 328    *
 329    *)
 330
 331   (* recognized macro of standard.h (or other) *)
 332   | PToken ({tok = TIdent (s,i1)} as id)::Parenthised (xxs,info_parens)::xs
 333       when Hashtbl.mem defs s ->
 334
 335       msg_apply_known_macro s;
 336       let (s, params, body) = Hashtbl.find defs s in
 337
 338       (match params with
 339       | NoParam ->
 340           pr2 ("WEIRD: macro without param used before parenthize: " ^ s);
 341           (* ex: PRINTP("NCR53C400 card%s detected\n" ANDP(((struct ... *)
 342
 343           (match body with
 344           | DefineBody bodymacro ->
 345               set_as_comment (Token_c.CppMacro) id;
 346               id.new_tokens_before <- bodymacro;
 347           | DefineHint hint ->
 348               msg_apply_known_macro_hint s;
 349               id.tok <- token_from_parsinghack_hint (s,i1) hint;
 350           )
 351       | Params params ->
 352           (match body with
 353           | DefineBody bodymacro ->
 354
 355               (* bugfix: better to put this that before the match body,
 356                  * cos our macrostatement hint can have variable number of
 357                  * arguments and so it's ok if it does not match exactly
 358                  * the number of arguments. *)
 359               let build_binder params xxs =
 360                 let rec loop = function
 361                     ([],[]) -> Some (function [] -> [] | _ -> failwith "bad")
 362                   | ([],[[]]) -> Some (function [[]] -> [] | _ -> failwith "bad")
 363                   | ([],l) -> None
 364                   | ([(VariadicArg s)],l) ->
 365                       Some (function l -> List.map (function a -> (s,a)) l)
 366                   | ((VariadicArg _)::_,l) -> None
 367                   | ((FixedArg _)::_,[]) -> None
 368                   | ((FixedArg s)::rest,x::xs) ->
 369                       (match loop (rest,xs) with
 370                         Some k ->
 371                           Some (function l -> (s,(List.hd l)) :: k (List.tl l))
 372                       | None -> None) in
 373                 loop (params, xxs) in
 374               (match build_binder params xxs with
 375                 None ->
 376                   pr2_once
 377                     ("WEIRD: macro with wrong number of arguments: " ^ s);
 378                   (* old: id.new_tokens_before <- bodymacro; *)
 379
 380                   (* update: if wrong number, then I just pass this macro *)
 381                   [Parenthised (xxs, info_parens)] +>
 382                   iter_token_paren (set_as_comment Token_c.CppMacro);
 383                   set_as_comment Token_c.CppMacro id
 384               | Some bind ->
 385
 386                   let xxs' = xxs +> List.map (fun x ->
 387                     (tokens_of_paren_ordered x) +> List.map (fun x ->
 388                       TH.visitor_info_of_tok Ast_c.make_expanded x.tok
 389                         )
 390                       ) in
 391                   id.new_tokens_before <-
 392                       (* !!! cpp expansion job here  !!! *)
 393                     cpp_engine ?evaluate_concatop
 394                       (bind xxs') bodymacro;
 395
 396                       (* important to do that after have apply the macro,
 397                          otherwise will pass as argument to the macro some
 398                          tokens that are all TCommentCpp
 399                       *)
 400                   [Parenthised (xxs, info_parens)] +>
 401                   iter_token_paren (set_as_comment Token_c.CppMacro);
 402                   set_as_comment Token_c.CppMacro id)
 403
 404           | DefineHint (HintMacroStatement as hint) ->
 405                 (* important to do that after have apply the macro, otherwise
 406                    * will pass as argument to the macro some tokens that
 407                  * are all TCommentCpp
 408                  *
 409                  * note: such macrostatement can have a variable number of
 410                  * arguments but here we don't care, we just pass all the
 411                  * parameters.
 412                  *)
 413
 414                 (match xs with
 415                 | PToken ({tok = TPtVirg _} as id2)::_ ->
 416                     pr2_once
 417                       ("macro stmt with trailing ';', passing also ';' for: "^
 418                        s);
 419                     (* sometimes still want pass its params ... as in
 420                      *  DEBUGPOLL(static unsigned int prev_mask = 0);
 421                      *)
 422
 423                     msg_apply_known_macro_hint s;
 424                     id.tok <- token_from_parsinghack_hint (s,i1) hint;
 425                     [Parenthised (xxs, info_parens)] +>
 426                       iter_token_paren (set_as_comment Token_c.CppMacro);
 427                     set_as_comment Token_c.CppMacro id2;
 428
 429                 | _ ->
 430                     msg_apply_known_macro_hint s;
 431                     id.tok <- token_from_parsinghack_hint (s,i1) hint;
 432                     [Parenthised (xxs, info_parens)] +>
 433                       iter_token_paren (set_as_comment Token_c.CppMacro);
 434                 )
 435
 436
 437             | DefineHint hint ->
 438                 msg_apply_known_macro_hint s;
 439                 id.tok <- token_from_parsinghack_hint (s,i1) hint;
 440             )
 441       );
 442       apply_macro_defs xs
 443
 444   | PToken ({tok = TIdent (s,i1)} as id)::xs
 445       when Hashtbl.mem defs s ->
 446
 447       msg_apply_known_macro s;
 448       let (_s, params, body) = Hashtbl.find defs s in
 449
 450       (match params with
 451       | Params _ ->
 452           pr2 ("WEIRD: macro with params but no parens found: " ^ s);
 453           (* dont apply the macro, perhaps a redefinition *)
 454           ()
 455       | NoParam ->
 456           (match body with
 457           (* bugfix: we prefer not using this special case when we come
 458            * from extract_macros context
 459            *)
 460           | DefineBody [newtok] when inplace_when_single ->
 461              (* special case when 1-1 substitution, we reuse the token *)
 462               id.tok <- (newtok +> TH.visitor_info_of_tok (fun _ ->
 463                 TH.info_of_tok id.tok))
 464           | DefineBody bodymacro ->
 465               set_as_comment Token_c.CppMacro id;
 466               id.new_tokens_before <- bodymacro;
 467           | DefineHint hint ->
 468                 msg_apply_known_macro_hint s;
 469                 id.tok <- token_from_parsinghack_hint (s,i1) hint;
 470           )
 471       );
 472       apply_macro_defs xs
 473
 474
 475
 476
 477   (* recurse *)
 478   | (PToken x)::xs -> apply_macro_defs xs
 479   | (Parenthised (xxs, info_parens))::xs ->
 480       xxs +> List.iter apply_macro_defs;
 481       apply_macro_defs xs
 482  in
 483  apply_macro_defs xs
 484
 485
 486
 487 (*****************************************************************************)
 488 (* extracting define_def from a standard.h  *)
 489 (*****************************************************************************)
 490 (* was the cpp-builtin, standard.h, part 0 *)
 491
 492 let macro_body_to_maybe_hint body =
 493   match body with
 494   | [] -> DefineBody body
 495   | [TIdent (s,i1)] ->
 496       (match parsinghack_hint_of_string s with
 497       | Some hint -> DefineHint hint
 498       | None -> DefineBody body
 499       )
 500   | xs -> DefineBody body
 501
 502 exception Bad_param
 503
 504 let rec (define_parse: Parser_c.token list -> (string * define_def) list) =
 505  fun xs ->
 506   match xs with
 507   | [] -> []
 508   | TDefine i1::TIdentDefine (s,i2)::TOParDefine i3::xs ->
 509       (* note: the macro could be badly written and have no closing ')' for
 510        * its param, which would make us go too far away, but I don't think
 511        * it's important to handle such an error *)
 512       let def =
 513         try
 514           let (tokparams, _, xs) =
 515             xs +> Common.split_when (function TCPar _ -> true | _ -> false) in
 516           let (body, _, xs) =
 517             xs +> Common.split_when (function TDefEOL _ -> true | _ -> false) in
 518           let params =
 519             tokparams +> Common.map_filter (function
 520               |  TComma _ -> None
 521               |  TIdent (s, _) -> Some (FixedArg s)
 522
 523               (* TODO *)
 524               |  TDefParamVariadic (s, _) -> Some (VariadicArg s)
 525               (* TODO *)
 526               |  TEllipsis _ -> Some (VariadicArg "...")
 527
 528               |  x ->
 529               (* bugfix: param of macros can be tricky *)
 530                   let s = TH.str_of_tok x in
 531                   if s ==~ Common.regexp_alpha
 532                   then begin
 533                     pr2 (spf "remapping: %s to a macro parameter" s);
 534                     Some (FixedArg s)
 535                   end
 536                   else
 537                     begin
 538                       pr2 (spf "bad character %s in macro parameter list" s);
 539                       raise Bad_param
 540                     end) in
 541           (* bugfix: also substitute to ident in body so cpp_engine will
 542              * have an easy job.
 543           *)
 544           let body = body +> List.map (fun tok ->
 545             match tok with
 546             | TIdent _ -> tok
 547             | _ ->
 548                 let s = TH.str_of_tok tok in
 549                 let ii = TH.info_of_tok tok in
 550                 let params =
 551                   List.map
 552                     (function FixedArg s -> s | VariadicArg s -> s)
 553                     params in
 554                 if s ==~ Common.regexp_alpha && List.mem s params
 555                 then begin
 556                   pr2 (spf "remapping: %s to an ident in macro body" s);
 557                   TIdent (s, ii)
 558                 end
 559                 else tok) +>
 560             List.map (TH.visitor_info_of_tok Ast_c.make_expanded) in
 561           Some (s, (s, Params params, macro_body_to_maybe_hint body))
 562         with Bad_param -> None in
 563       (match def with
 564         Some def -> def::define_parse xs
 565       | None -> define_parse xs)
 566
 567   | TDefine i1::TIdentDefine (s,i2)::xs ->
 568       let (body, _, xs) =
 569         xs +> Common.split_when (function TDefEOL _ -> true | _ -> false) in
 570       let body = body +> List.map
 571         (TH.visitor_info_of_tok Ast_c.make_expanded) in
 572       let def = (s, (s, NoParam, macro_body_to_maybe_hint body)) in
 573       def::define_parse xs
 574
 575   (* cf tests-bis/define_plus.c *)
 576   | TDefine i1::xs ->
 577       let line = Ast_c.line_of_info i1 in
 578       pr2 (spf "WEIRD: no ident in define at line %d" line);
 579       define_parse xs
 580
 581   | x::xs -> define_parse xs
 582
 583
 584
 585 let extract_macros xs =
 586   let cleaner = xs +> List.filter (fun x ->
 587     not (TH.is_comment x)
 588   ) in
 589   define_parse cleaner
 590
 591