data/c++.m4

   1                                                             -*- Autoconf -*-
   2
   3 # C++ skeleton for Bison
   4
   5 # Copyright (C) 2002-2013 Free Software Foundation, Inc.
   6
   7 # This program is free software: you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation, either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 m4_include(b4_pkgdatadir/[c.m4])
  21
  22 # b4_comment(TEXT, [PREFIX])
  23 # --------------------------
  24 # Put TEXT in comment. Prefix all the output lines with PREFIX.
  25 m4_define([b4_comment],
  26 [b4_comment_([$1], [$2// ], [$2// ])])
  27
  28
  29 ## ---------------- ##
  30 ## Default values.  ##
  31 ## ---------------- ##
  32
  33 b4_percent_define_default([[parser_class_name]], [[parser]])
  34
  35 # Don't do that so that we remember whether we're using a user
  36 # request, or the default value.
  37 #
  38 # b4_percent_define_default([[api.location.type]], [[location]])
  39
  40 b4_percent_define_default([[filename_type]], [[std::string]])
  41 b4_percent_define_default([[api.namespace]], m4_defn([b4_prefix]))
  42
  43 b4_percent_define_default([[global_tokens_and_yystype]], [[false]])
  44 b4_percent_define_default([[define_location_comparison]],
  45                           [m4_if(b4_percent_define_get([[filename_type]]),
  46                                  [std::string], [[true]], [[false]])])
  47
  48
  49
  50 ## ----------- ##
  51 ## Namespace.  ##
  52 ## ----------- ##
  53
  54 m4_define([b4_namespace_ref], [b4_percent_define_get([[api.namespace]])])
  55
  56
  57 # Don't permit an empty b4_namespace_ref.  Any '::parser::foo' appended to it
  58 # would compile as an absolute reference with 'parser' in the global namespace.
  59 # b4_namespace_open would open an anonymous namespace and thus establish
  60 # internal linkage.  This would compile.  However, it's cryptic, and internal
  61 # linkage for the parser would be specified in all translation units that
  62 # include the header, which is always generated.  If we ever need to permit
  63 # internal linkage somehow, surely we can find a cleaner approach.
  64 m4_if(m4_bregexp(b4_namespace_ref, [^[   ]*$]), [-1], [],
  65 [b4_complain_at(b4_percent_define_get_loc([[api.namespace]]),
  66                 [[namespace reference is empty]])])
  67
  68 # Instead of assuming the C++ compiler will do it, Bison should reject any
  69 # invalid b4_namepsace_ref that would be converted to a valid
  70 # b4_namespace_open.  The problem is that Bison doesn't always output
  71 # b4_namespace_ref to uncommented code but should reserve the ability to do so
  72 # in future releases without risking breaking any existing user grammars.
  73 # Specifically, don't allow empty names as b4_namespace_open would just convert
  74 # those into anonymous namespaces, and that might tempt some users.
  75 m4_if(m4_bregexp(b4_namespace_ref, [::[  ]*::]), [-1], [],
  76 [b4_complain_at(b4_percent_define_get_loc([[api.namespace]]),
  77                 [[namespace reference has consecutive "::"]])])
  78 m4_if(m4_bregexp(b4_namespace_ref, [::[  ]*$]), [-1], [],
  79 [b4_complain_at(b4_percent_define_get_loc([[api.namespace]]),
  80                 [[namespace reference has a trailing "::"]])])
  81
  82 m4_define([b4_namespace_open],
  83 [b4_user_code([b4_percent_define_get_syncline([[api.namespace]])
  84 [namespace ]m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref),
  85                                                 [^\(.\)[         ]*::], [\1])),
  86                          [::], [ { namespace ])[ {]])])
  87
  88 m4_define([b4_namespace_close],
  89 [b4_user_code([b4_percent_define_get_syncline([[api.namespace]])
  90 m4_bpatsubst(m4_dquote(m4_bpatsubst(m4_dquote(b4_namespace_ref[ ]),
  91                                     [^\(.\)[     ]*\(::\)?\([^][:]\|:[^:]\)*],
  92                                     [\1])),
  93              [::\([^][:]\|:[^:]\)*], [} ])[} // ]b4_namespace_ref])])
  94
  95
  96 # b4_token_enums
  97 # --------------
  98 # Output the definition of the tokens as enums.
  99 m4_define([b4_token_enums],
 100 [[enum yytokentype
 101       {
 102         ]m4_join([,
 103         ],
 104                  b4_symbol_map([b4_token_enum]))[
 105       };]dnl
 106 ])
 107
 108
 109
 110
 111 ## ----------------- ##
 112 ## Semantic Values.  ##
 113 ## ----------------- ##
 114
 115
 116
 117 # b4_value_type_declare
 118 # ---------------------
 119 # Declare semantic_type.
 120 m4_define([b4_value_type_declare],
 121 [    /// Symbol semantic values.
 122 m4_ifdef([b4_union_members],
 123 [    union semantic_type
 124     {
 125 b4_user_union_members
 126     };],
 127 [m4_if(b4_tag_seen_flag, 0,
 128 [[    typedef int semantic_type;]],
 129 [[    typedef ]b4_api_PREFIX[STYPE semantic_type;]])])])
 130
 131
 132 # b4_public_types_declare
 133 # -----------------------
 134 # Define the public types: token, semantic value, location, and so forth.
 135 # Depending on %define token_lex, may be output in the header or source file.
 136 m4_define([b4_public_types_declare],
 137 [[#ifndef ]b4_api_PREFIX[STYPE
 138 ]b4_value_type_declare[
 139 #else
 140     typedef ]b4_api_PREFIX[STYPE semantic_type;
 141 #endif]b4_locations_if([
 142     /// Symbol locations.
 143     typedef b4_percent_define_get([[api.location.type]],
 144                                   [[location]]) location_type;])[
 145
 146     /// Syntax errors thrown from user actions.
 147     struct syntax_error : std::runtime_error
 148     {
 149       syntax_error (]b4_locations_if([const location_type& l, ])[const std::string& m);]b4_locations_if([
 150       location_type location;])[
 151     };
 152
 153     /// Tokens.
 154     struct token
 155     {
 156       ]b4_token_enums[
 157     };
 158
 159     /// (External) token type, as returned by yylex.
 160     typedef token::yytokentype token_type;
 161
 162     /// Internal symbol number.
 163     typedef int symbol_number_type;
 164
 165     /// Internal symbol number for tokens (subsumed by symbol_number_type).
 166     typedef ]b4_int_type_for([b4_translate])[ token_number_type;
 167
 168     /// A complete symbol.
 169     ///
 170     /// Expects its Base type to provide access to the symbol type
 171     /// via type_get().
 172     ///
 173     /// Provide access to semantic value]b4_locations_if([ and location])[.
 174     template <typename Base>
 175     struct basic_symbol : Base
 176     {
 177       /// Alias to Base.
 178       typedef Base super_type;
 179
 180       /// Default constructor.
 181       basic_symbol ();
 182
 183       /// Copy constructor.
 184       basic_symbol (const basic_symbol& other);
 185 ]b4_variant_if([[
 186       /// Constructor for valueless symbols, and symbols from each type.
 187 ]b4_type_foreach([b4_basic_symbol_constructor_declare])], [[
 188       /// Constructor for valueless symbols.
 189       basic_symbol (typename Base::kind_type t]b4_locations_if([,
 190                     const location_type& l])[);]])[
 191
 192       /// Constructor for symbols with semantic value.
 193       basic_symbol (typename Base::kind_type t,
 194                     const semantic_type& v]b4_locations_if([,
 195                     const location_type& l])[);
 196
 197       ~basic_symbol ();
 198
 199       /// Destructive move, \a s is emptied into this.
 200       void move (basic_symbol& s);
 201
 202       /// The semantic value.
 203       semantic_type value;]b4_locations_if([
 204
 205       /// The location.
 206       location_type location;])[
 207
 208     private:
 209       /// Assignment operator.
 210       basic_symbol& operator= (const basic_symbol& other);
 211     };
 212
 213     /// Type access provider for token (enum) based symbols.
 214     struct by_type
 215     {
 216       /// Default constructor.
 217       by_type ();
 218
 219       /// Copy constructor.
 220       by_type (const by_type& other);
 221
 222       /// The symbol type as needed by the constructor.
 223       typedef token_type kind_type;
 224
 225       /// Constructor from (external) token numbers.
 226       by_type (kind_type t);
 227
 228       /// Steal the symbol type from \a that.
 229       void move (by_type& that);
 230
 231       /// The (internal) type number (corresponding to \a type).
 232       /// -1 when this symbol is empty.
 233       symbol_number_type type_get () const;
 234
 235       /// The token.
 236       token_type token () const;
 237
 238       enum { empty = 0 };
 239
 240       /// The symbol type.
 241       /// -1 when this symbol is empty.
 242       token_number_type type;
 243     };
 244
 245     /// "External" symbols: returned by the scanner.
 246     typedef basic_symbol<by_type> symbol_type;
 247
 248 ]b4_symbol_constructor_declare])
 249
 250
 251 # b4_public_types_define
 252 # ----------------------
 253 # Provide the implementation needed by the public types.
 254 m4_define([b4_public_types_define],
 255 [[  inline
 256   ]b4_parser_class_name[::syntax_error::syntax_error (]b4_locations_if([const location_type& l, ])[const std::string& m)
 257     : std::runtime_error (m)]b4_locations_if([
 258     , location (l)])[
 259   {}
 260
 261   // basic_symbol.
 262   template <typename Base>
 263   inline
 264   ]b4_parser_class_name[::basic_symbol<Base>::basic_symbol ()
 265     : value ()
 266   {}
 267
 268   template <typename Base>
 269   inline
 270   ]b4_parser_class_name[::basic_symbol<Base>::basic_symbol (const basic_symbol& other)
 271     : Base (other)
 272     , value ()]b4_locations_if([
 273     , location (other.location)])[
 274   {
 275     ]b4_variant_if([b4_symbol_variant([other.type_get ()], [value], [copy],
 276                                       [other.value])],
 277                    [value = other.value;])[
 278   }
 279
 280
 281   template <typename Base>
 282   inline
 283   ]b4_parser_class_name[::basic_symbol<Base>::basic_symbol (]b4_join(
 284           [typename Base::kind_type t],
 285           [const semantic_type& v],
 286           b4_locations_if([const location_type& l]))[)
 287     : Base (t)
 288     , value (]b4_variant_if([], [v])[)]b4_locations_if([
 289     , location (l)])[
 290   {]b4_variant_if([[
 291     (void) v;
 292     ]b4_symbol_variant([this->type_get ()], [value], [copy], [v])])[}
 293
 294 ]b4_variant_if([[
 295   // Implementation of basic_symbol constructor for each type.
 296 ]b4_type_foreach([b4_basic_symbol_constructor_define])], [[
 297   /// Constructor for valueless symbols.
 298   template <typename Base>
 299   inline
 300   ]b4_parser_class_name[::basic_symbol<Base>::basic_symbol (]b4_join(
 301           [typename Base::kind_type t],
 302           b4_locations_if([const location_type& l]))[)
 303     : Base (t)
 304     , value ()]b4_locations_if([
 305     , location (l)])[
 306   {}]])[
 307
 308   template <typename Base>
 309   inline
 310   ]b4_parser_class_name[::basic_symbol<Base>::~basic_symbol ()
 311   {]b4_variant_if([[
 312     // User destructor.
 313     symbol_number_type yytype = this->type_get ();
 314     switch (yytype)
 315     {
 316 ]b4_symbol_foreach([b4_symbol_destructor])dnl
 317 [   default:
 318       break;
 319     }
 320
 321     // Type destructor.
 322   ]b4_symbol_variant([[yytype]], [[value]], [[template destroy]])])[
 323   }
 324
 325   template <typename Base>
 326   inline
 327   void
 328   ]b4_parser_class_name[::basic_symbol<Base>::move (basic_symbol& s)
 329   {
 330     super_type::move(s);
 331     ]b4_variant_if([b4_symbol_variant([this->type_get ()], [value], [move],
 332                                       [s.value])],
 333                    [value = s.value;])[]b4_locations_if([
 334     location = s.location;])[
 335   }
 336
 337   // by_type.
 338   inline
 339   ]b4_parser_class_name[::by_type::by_type ()
 340      : type (empty)
 341   {}
 342
 343   inline
 344   ]b4_parser_class_name[::by_type::by_type (const by_type& other)
 345     : type (other.type)
 346   {}
 347
 348   inline
 349   ]b4_parser_class_name[::by_type::by_type (token_type t)
 350     : type (yytranslate_ (t))
 351   {}
 352
 353   inline
 354   void
 355   ]b4_parser_class_name[::by_type::move (by_type& that)
 356   {
 357     type = that.type;
 358     that.type = empty;
 359   }
 360
 361   inline
 362   int
 363   ]b4_parser_class_name[::by_type::type_get () const
 364   {
 365     return type;
 366   }
 367 ]b4_token_ctor_if([[
 368   inline
 369   ]b4_parser_class_name[::token_type
 370   ]b4_parser_class_name[::by_type::token () const
 371   {
 372     // YYTOKNUM[NUM] -- (External) token number corresponding to the
 373     // (internal) symbol number NUM (which must be that of a token).  */
 374     static
 375     const ]b4_int_type_for([b4_toknum])[
 376     yytoken_number_[] =
 377     {
 378   ]b4_toknum[
 379     };
 380     return static_cast<token_type> (yytoken_number_[type]);
 381   }
 382 ]])[]dnl
 383 b4_symbol_constructor_define])
 384
 385
 386 # b4_symbol_constructor_declare
 387 # b4_symbol_constructor_define
 388 # -----------------------------
 389 # Declare/define symbol constructors for all the value types.
 390 # Use at class-level.  Redefined in variant.hh.
 391 m4_define([b4_symbol_constructor_declare], [])
 392 m4_define([b4_symbol_constructor_define], [])
 393
 394
 395 # b4_yytranslate_define
 396 # ---------------------
 397 # Define yytranslate_.  Sometimes used in the header file,
 398 # sometimes in the cc file.
 399 m4_define([b4_yytranslate_define],
 400 [[  // Symbol number corresponding to token number t.
 401   inline
 402   ]b4_parser_class_name[::token_number_type
 403   ]b4_parser_class_name[::yytranslate_ (]b4_token_ctor_if([token_type],
 404                                                           [int])[ t)
 405   {
 406     static
 407     const token_number_type
 408     translate_table[] =
 409     {
 410 ]b4_translate[
 411     };
 412     const unsigned int user_token_number_max_ = ]b4_user_token_number_max[;
 413     const token_number_type undef_token_ = ]b4_undef_token_number[;
 414
 415     if (static_cast<int>(t) <= yyeof_)
 416       return yyeof_;
 417     else if (static_cast<unsigned int> (t) <= user_token_number_max_)
 418       return translate_table[t];
 419     else
 420       return undef_token_;
 421   }
 422 ]])
 423
 424
 425 # b4_lhs_value([TYPE])
 426 # --------------------
 427 # Expansion of $<TYPE>$.
 428 m4_define([b4_lhs_value],
 429 [b4_symbol_value([yyval], [$1])])
 430
 431
 432 # b4_rhs_value(RULE-LENGTH, NUM, [TYPE])
 433 # --------------------------------------
 434 # Expansion of $<TYPE>NUM, where the current rule has RULE-LENGTH
 435 # symbols on RHS.
 436 m4_define([b4_rhs_value],
 437 [b4_symbol_value([yysemantic_stack_@{($1) - ($2)@}], [$3])])
 438
 439
 440 # b4_lhs_location()
 441 # -----------------
 442 # Expansion of @$.
 443 m4_define([b4_lhs_location],
 444 [(yyloc)])
 445
 446
 447 # b4_rhs_location(RULE-LENGTH, NUM)
 448 # ---------------------------------
 449 # Expansion of @NUM, where the current rule has RULE-LENGTH symbols
 450 # on RHS.
 451 m4_define([b4_rhs_location],
 452 [(yylocation_stack_@{($1) - ($2)@})])
 453
 454
 455 # b4_parse_param_decl
 456 # -------------------
 457 # Extra formal arguments of the constructor.
 458 # Change the parameter names from "foo" into "foo_yyarg", so that
 459 # there is no collision bw the user chosen attribute name, and the
 460 # argument name in the constructor.
 461 m4_define([b4_parse_param_decl],
 462 [m4_ifset([b4_parse_param],
 463           [m4_map_sep([b4_parse_param_decl_1], [, ], [b4_parse_param])])])
 464
 465 m4_define([b4_parse_param_decl_1],
 466 [$1_yyarg])
 467
 468
 469
 470 # b4_parse_param_cons
 471 # -------------------
 472 # Extra initialisations of the constructor.
 473 m4_define([b4_parse_param_cons],
 474           [m4_ifset([b4_parse_param],
 475                     [
 476       b4_cc_constructor_calls(b4_parse_param)])])
 477 m4_define([b4_cc_constructor_calls],
 478           [m4_map_sep([b4_cc_constructor_call], [,
 479       ], [$@])])
 480 m4_define([b4_cc_constructor_call],
 481           [$2 ($2_yyarg)])
 482
 483 # b4_parse_param_vars
 484 # -------------------
 485 # Extra instance variables.
 486 m4_define([b4_parse_param_vars],
 487           [m4_ifset([b4_parse_param],
 488                     [
 489     // User arguments.
 490 b4_cc_var_decls(b4_parse_param)])])
 491 m4_define([b4_cc_var_decls],
 492           [m4_map_sep([b4_cc_var_decl], [
 493 ], [$@])])
 494 m4_define([b4_cc_var_decl],
 495           [    $1;])
 496
 497
 498 ## ---------##
 499 ## Values.  ##
 500 ## ---------##
 501
 502 # b4_yylloc_default_define
 503 # ------------------------
 504 # Define YYLLOC_DEFAULT.
 505 m4_define([b4_yylloc_default_define],
 506 [[/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N].
 507    If N is 0, then set CURRENT to the empty location which ends
 508    the previous symbol: RHS[0] (always defined).  */
 509
 510 # ifndef YYLLOC_DEFAULT
 511 #  define YYLLOC_DEFAULT(Current, Rhs, N)                               \
 512     do                                                                  \
 513       if (N)                                                            \
 514         {                                                               \
 515           (Current).begin  = YYRHSLOC (Rhs, 1).begin;                   \
 516           (Current).end    = YYRHSLOC (Rhs, N).end;                     \
 517         }                                                               \
 518       else                                                              \
 519         {                                                               \
 520           (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end;      \
 521         }                                                               \
 522     while (/*CONSTCOND*/ false)
 523 # endif
 524 ]])
 525
 526 ## -------- ##
 527 ## Checks.  ##
 528 ## -------- ##
 529
 530 b4_token_ctor_if([b4_variant_if([],
 531   [b4_fatal_at(b4_percent_define_get_loc(api.token.constructor),
 532                [cannot use '%s' without '%s'],
 533                [%define api.token.constructor],
 534                [%define api.value.type variant]))])])