src/parse-gram.y

   1 %{/* Bison Grammar Parser                             -*- C -*-
   2
   3    Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include "complain.h"
  25 #include "conflicts.h"
  26 #include "files.h"
  27 #include "getargs.h"
  28 #include "gram.h"
  29 #include "muscle_tab.h"
  30 #include "quotearg.h"
  31 #include "reader.h"
  32 #include "symlist.h"
  33 #include "scan-gram.h"
  34 #include "scan-code.h"
  35
  36 #define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
  37 static YYLTYPE lloc_default (YYLTYPE const *, int);
  38
  39 #define YY_LOCATION_PRINT(File, Loc) \
  40           location_print (File, Loc)
  41
  42 static void version_check (location const *loc, char const *version);
  43
  44 /* Request detailed syntax error messages, and pass them to GRAM_ERROR.
  45    FIXME: depends on the undocumented availability of YYLLOC.  */
  46 #undef  yyerror
  47 #define yyerror(Msg) \
  48         gram_error (&yylloc, Msg)
  49 static void gram_error (location const *, char const *);
  50
  51 static char const *char_name (char);
  52
  53 /** Add a lex-param or a parse-param.
  54  *
  55  * \param type  \a lex_param or \a parse_param
  56  * \param decl  the formal argument
  57  * \param loc   the location in the source.
  58  */
  59 static void add_param (char const *type, char *decl, location loc);
  60
  61
  62 static symbol_class current_class = unknown_sym;
  63 static uniqstr current_type = NULL;
  64 static symbol *current_lhs;
  65 static location current_lhs_location;
  66 static int current_prec = 0;
  67
  68 #define YYTYPE_INT16 int_fast16_t
  69 #define YYTYPE_INT8 int_fast8_t
  70 #define YYTYPE_UINT16 uint_fast16_t
  71 #define YYTYPE_UINT8 uint_fast8_t
  72 %}
  73
  74 %debug
  75 %verbose
  76 %defines
  77 %locations
  78 %pure-parser
  79 %error-verbose
  80 %name-prefix="gram_"
  81 %expect 0
  82
  83 %initial-action
  84 {
  85   /* Bison's grammar can initial empty locations, hence a default
  86      location is needed. */
  87   boundary_set (&@$.start, current_file, 1, 1);
  88   boundary_set (&@$.end, current_file, 1, 1);
  89 }
  90
  91 %union
  92 {
  93   symbol *symbol;
  94   symbol_list *list;
  95   int integer;
  96   char const *chars;
  97   char *code;
  98   assoc assoc;
  99   uniqstr uniqstr;
 100   unsigned char character;
 101 };
 102
 103 /* Define the tokens together with their human representation.  */
 104 %token GRAM_EOF 0 "end of file"
 105 %token STRING     "string"
 106 %token INT        "integer"
 107
 108 %token PERCENT_TOKEN       "%token"
 109 %token PERCENT_NTERM       "%nterm"
 110
 111 %token PERCENT_TYPE        "%type"
 112 %token PERCENT_DESTRUCTOR  "%destructor"
 113 %token PERCENT_PRINTER     "%printer"
 114
 115 %token PERCENT_LEFT        "%left"
 116 %token PERCENT_RIGHT       "%right"
 117 %token PERCENT_NONASSOC    "%nonassoc"
 118
 119 %token PERCENT_PREC          "%prec"
 120 %token PERCENT_DPREC         "%dprec"
 121 %token PERCENT_MERGE         "%merge"
 122
 123
 124 /*----------------------.
 125 | Global Declarations.  |
 126 `----------------------*/
 127
 128 %token
 129   PERCENT_CODE            "%code"
 130   PERCENT_DEBUG           "%debug"
 131   PERCENT_DEFAULT_PREC    "%default-prec"
 132   PERCENT_DEFINE          "%define"
 133   PERCENT_DEFINES         "%defines"
 134   PERCENT_ERROR_VERBOSE   "%error-verbose"
 135   PERCENT_EXPECT          "%expect"
 136   PERCENT_EXPECT_RR       "%expect-rr"
 137   PERCENT_FILE_PREFIX     "%file-prefix"
 138   PERCENT_GLR_PARSER      "%glr-parser"
 139   PERCENT_INITIAL_ACTION  "%initial-action"
 140   PERCENT_LANGUAGE        "%language"
 141   PERCENT_LEX_PARAM       "%lex-param"
 142   PERCENT_LOCATIONS       "%locations"
 143   PERCENT_NAME_PREFIX     "%name-prefix"
 144   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
 145   PERCENT_NO_LINES        "%no-lines"
 146   PERCENT_NONDETERMINISTIC_PARSER
 147                           "%nondeterministic-parser"
 148   PERCENT_OUTPUT          "%output"
 149   PERCENT_PARSE_PARAM     "%parse-param"
 150   PERCENT_PURE_PARSER     "%pure-parser"
 151   PERCENT_REQUIRE         "%require"
 152   PERCENT_SKELETON        "%skeleton"
 153   PERCENT_START           "%start"
 154   PERCENT_TOKEN_TABLE     "%token-table"
 155   PERCENT_VERBOSE         "%verbose"
 156   PERCENT_YACC            "%yacc"
 157 ;
 158
 159 %token BRACED_CODE     "{...}"
 160 %token CHAR            "char"
 161 %token EPILOGUE        "epilogue"
 162 %token EQUAL           "="
 163 %token ID              "identifier"
 164 %token ID_COLON        "identifier:"
 165 %token PERCENT_PERCENT "%%"
 166 %token PIPE            "|"
 167 %token PROLOGUE        "%{...%}"
 168 %token SEMICOLON       ";"
 169 %token TYPE            "type"
 170 %token TYPE_TAG_ANY    "<*>"
 171 %token TYPE_TAG_NONE   "<>"
 172
 173 %type <character> CHAR
 174 %printer { fputs (char_name ($$), stderr); } CHAR
 175
 176 /* braceless is not to be used for rule or symbol actions, as it
 177    calls code_props_plain_init.  */
 178 %type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
 179 %type <code> "{...}"
 180 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
 181          STRING
 182 %printer { fprintf (stderr, "{\n%s\n}", $$); }
 183          braceless content.opt "{...}" "%{...%}" EPILOGUE
 184
 185 %type <uniqstr> TYPE ID ID_COLON variable
 186 %printer { fprintf (stderr, "<%s>", $$); } TYPE
 187 %printer { fputs ($$, stderr); } ID variable
 188 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
 189
 190 %type <integer> INT
 191 %printer { fprintf (stderr, "%d", $$); } INT
 192
 193 %type <symbol> id id_colon symbol symbol.prec string_as_id
 194 %printer { fprintf (stderr, "%s", $$->tag); } id symbol string_as_id
 195 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 196
 197 %type <assoc> precedence_declarator
 198 %type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
 199 %%
 200
 201 input:
 202   prologue_declarations "%%" grammar epilogue.opt
 203 ;
 204
 205
 206         /*------------------------------------.
 207         | Declarations: before the first %%.  |
 208         `------------------------------------*/
 209
 210 prologue_declarations:
 211   /* Nothing */
 212 | prologue_declarations prologue_declaration
 213 ;
 214
 215 prologue_declaration:
 216   grammar_declaration
 217 | "%{...%}"
 218     {
 219       code_props plain_code;
 220       code_props_plain_init (&plain_code, $1, @1);
 221       code_props_translate_code (&plain_code);
 222       gram_scanner_last_string_free ();
 223       muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
 224                         plain_code.code, @1);
 225       code_scanner_last_string_free ();
 226     }
 227 | "%debug"                         { debug_flag = true; }
 228 | "%define" variable content.opt
 229     {
 230       muscle_percent_define_insert ($2, @2, $3);
 231     }
 232 | "%defines"                       { defines_flag = true; }
 233 | "%defines" STRING
 234     {
 235       defines_flag = true;
 236       spec_defines_file = xstrdup ($2);
 237     }
 238 | "%error-verbose"                 { error_verbose = true; }
 239 | "%expect" INT                    { expected_sr_conflicts = $2; }
 240 | "%expect-rr" INT                 { expected_rr_conflicts = $2; }
 241 | "%file-prefix" STRING            { spec_file_prefix = $2; }
 242 | "%file-prefix" "=" STRING        { spec_file_prefix = $3; } /* deprecated */
 243 | "%glr-parser"
 244     {
 245       nondeterministic_parser = true;
 246       glr_parser = true;
 247     }
 248 | "%initial-action" "{...}"
 249     {
 250       code_props action;
 251       code_props_symbol_action_init (&action, $2, @2);
 252       code_props_translate_code (&action);
 253       gram_scanner_last_string_free ();
 254       muscle_code_grow ("initial_action", action.code, @2);
 255       code_scanner_last_string_free ();
 256     }
 257 | "%language" STRING            { language_argmatch ($2, 1, &@1); }
 258 | "%lex-param" "{...}"          { add_param ("lex_param", $2, @2); }
 259 | "%locations"                  { locations_flag = true; }
 260 | "%name-prefix" STRING         { spec_name_prefix = $2; }
 261 | "%name-prefix" "=" STRING     { spec_name_prefix = $3; } /* deprecated */
 262 | "%no-lines"                   { no_lines_flag = true; }
 263 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 264 | "%output" STRING              { spec_outfile = $2; }
 265 | "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
 266 | "%parse-param" "{...}"        { add_param ("parse_param", $2, @2); }
 267 | "%pure-parser"
 268     {
 269       /* %pure-parser is deprecated in favor of `%define api.pure', so use
 270          `%define api.pure' in a backward-compatible manner here.  First, don't
 271          complain if %pure-parser is specified multiple times.  */
 272       if (!muscle_find_const ("percent_define(api.pure)"))
 273         muscle_percent_define_insert ("api.pure", @1, "");
 274       /* In all cases, use api.pure now so that the backend doesn't complain if
 275          the skeleton ignores api.pure, but do warn now if there's a previous
 276          conflicting definition from an actual %define.  */
 277       if (!muscle_percent_define_flag_if ("api.pure"))
 278         muscle_percent_define_insert ("api.pure", @1, "");
 279     }
 280 | "%require" STRING             { version_check (&@2, $2); }
 281 | "%skeleton" STRING
 282     {
 283       char const *skeleton_user = $2;
 284       if (strchr (skeleton_user, '/'))
 285         {
 286           size_t dir_length = strlen (current_file);
 287           char *skeleton_build;
 288           while (dir_length && current_file[dir_length - 1] != '/')
 289             --dir_length;
 290           while (dir_length && current_file[dir_length - 1] == '/')
 291             --dir_length;
 292           skeleton_build =
 293             xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
 294           if (dir_length > 0)
 295             {
 296               strncpy (skeleton_build, current_file, dir_length);
 297               skeleton_build[dir_length++] = '/';
 298             }
 299           strcpy (skeleton_build + dir_length, skeleton_user);
 300           skeleton_user = uniqstr_new (skeleton_build);
 301           free (skeleton_build);
 302         }
 303       skeleton_arg (skeleton_user, 1, &@1);
 304     }
 305 | "%token-table"                { token_table_flag = true; }
 306 | "%verbose"                    { report_flag |= report_states; }
 307 | "%yacc"                       { yacc_flag = true; }
 308 | /*FIXME: Err?  What is this horror doing here? */ ";"
 309 ;
 310
 311 grammar_declaration:
 312   precedence_declaration
 313 | symbol_declaration
 314 | "%start" symbol
 315     {
 316       grammar_start_symbol_set ($2, @2);
 317     }
 318 | "%destructor" "{...}" generic_symlist
 319     {
 320       symbol_list *list;
 321       for (list = $3; list; list = list->next)
 322         symbol_list_destructor_set (list, $2, @2);
 323       symbol_list_free ($3);
 324     }
 325 | "%printer" "{...}" generic_symlist
 326     {
 327       symbol_list *list;
 328       for (list = $3; list; list = list->next)
 329         symbol_list_printer_set (list, $2, @2);
 330       symbol_list_free ($3);
 331     }
 332 | "%default-prec"
 333     {
 334       default_prec = true;
 335     }
 336 | "%no-default-prec"
 337     {
 338       default_prec = false;
 339     }
 340 | "%code" braceless
 341     {
 342       /* Do not invoke muscle_percent_code_grow here since it invokes
 343          muscle_user_name_list_grow.  */
 344       muscle_code_grow ("percent_code()", $2, @2);
 345       code_scanner_last_string_free ();
 346     }
 347 | "%code" ID braceless
 348     {
 349       muscle_percent_code_grow ($2, @2, $3, @3);
 350       code_scanner_last_string_free ();
 351     }
 352 ;
 353
 354
 355 /*---------.
 356 | %union.  |
 357 `---------*/
 358
 359 %token PERCENT_UNION "%union";
 360
 361 union_name:
 362   /* Nothing. */ {}
 363 | ID             { muscle_code_grow ("union_name", $1, @1); }
 364 ;
 365
 366 grammar_declaration:
 367   "%union" union_name braceless
 368     {
 369       union_seen = true;
 370       muscle_code_grow ("stype", $3, @3);
 371       code_scanner_last_string_free ();
 372     }
 373 ;
 374
 375
 376
 377
 378 symbol_declaration:
 379   "%nterm" { current_class = nterm_sym; } symbol_defs.1
 380     {
 381       current_class = unknown_sym;
 382       current_type = NULL;
 383     }
 384 | "%token" { current_class = token_sym; } symbol_defs.1
 385     {
 386       current_class = unknown_sym;
 387       current_type = NULL;
 388     }
 389 | "%type" TYPE symbols.1
 390     {
 391       symbol_list *list;
 392       tag_seen = true;
 393       for (list = $3; list; list = list->next)
 394         symbol_type_set (list->content.sym, $2, @2);
 395       symbol_list_free ($3);
 396     }
 397 ;
 398
 399 precedence_declaration:
 400   precedence_declarator type.opt symbols.prec
 401     {
 402       symbol_list *list;
 403       ++current_prec;
 404       for (list = $3; list; list = list->next)
 405         {
 406           symbol_type_set (list->content.sym, current_type, @2);
 407           symbol_precedence_set (list->content.sym, current_prec, $1, @1);
 408         }
 409       symbol_list_free ($3);
 410       current_type = NULL;
 411     }
 412 ;
 413
 414 precedence_declarator:
 415   "%left"     { $$ = left_assoc; }
 416 | "%right"    { $$ = right_assoc; }
 417 | "%nonassoc" { $$ = non_assoc; }
 418 ;
 419
 420 type.opt:
 421   /* Nothing. */ { current_type = NULL; }
 422 | TYPE           { current_type = $1; tag_seen = true; }
 423 ;
 424
 425 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
 426 symbols.prec:
 427   symbol.prec
 428     { $$ = symbol_list_sym_new ($1, @1); }
 429 | symbols.prec symbol.prec
 430     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 431 ;
 432
 433 symbol.prec:
 434     symbol { $$ = $1; }
 435   | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
 436   ;
 437
 438 /* One or more symbols to be %typed. */
 439 symbols.1:
 440   symbol
 441     { $$ = symbol_list_sym_new ($1, @1); }
 442 | symbols.1 symbol
 443     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 444 ;
 445
 446 generic_symlist:
 447   generic_symlist_item { $$ = $1; }
 448 | generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
 449 ;
 450
 451 generic_symlist_item:
 452   symbol            { $$ = symbol_list_sym_new ($1, @1); }
 453 | TYPE              { $$ = symbol_list_type_new ($1, @1); }
 454 | "<*>"             { $$ = symbol_list_default_tagged_new (@1); }
 455 | "<>"             { $$ = symbol_list_default_tagless_new (@1); }
 456 ;
 457
 458 /* One token definition.  */
 459 symbol_def:
 460   TYPE
 461      {
 462        current_type = $1;
 463        tag_seen = true;
 464      }
 465 | id
 466      {
 467        symbol_class_set ($1, current_class, @1, true);
 468        symbol_type_set ($1, current_type, @1);
 469      }
 470 | id INT
 471     {
 472       symbol_class_set ($1, current_class, @1, true);
 473       symbol_type_set ($1, current_type, @1);
 474       symbol_user_token_number_set ($1, $2, @2);
 475     }
 476 | id string_as_id
 477     {
 478       symbol_class_set ($1, current_class, @1, true);
 479       symbol_type_set ($1, current_type, @1);
 480       symbol_make_alias ($1, $2, @$);
 481     }
 482 | id INT string_as_id
 483     {
 484       symbol_class_set ($1, current_class, @1, true);
 485       symbol_type_set ($1, current_type, @1);
 486       symbol_user_token_number_set ($1, $2, @2);
 487       symbol_make_alias ($1, $3, @$);
 488     }
 489 ;
 490
 491 /* One or more symbol definitions. */
 492 symbol_defs.1:
 493   symbol_def
 494 | symbol_defs.1 symbol_def
 495 ;
 496
 497
 498         /*------------------------------------------.
 499         | The grammar section: between the two %%.  |
 500         `------------------------------------------*/
 501
 502 grammar:
 503   rules_or_grammar_declaration
 504 | grammar rules_or_grammar_declaration
 505 ;
 506
 507 /* As a Bison extension, one can use the grammar declarations in the
 508    body of the grammar.  */
 509 rules_or_grammar_declaration:
 510   rules
 511 | grammar_declaration ";"
 512 | error ";"
 513     {
 514       yyerrok;
 515     }
 516 ;
 517
 518 rules:
 519   id_colon { current_lhs = $1; current_lhs_location = @1; } rhses.1
 520 ;
 521
 522 rhses.1:
 523   rhs                { grammar_current_rule_end (@1); }
 524 | rhses.1 "|" rhs    { grammar_current_rule_end (@3); }
 525 | rhses.1 ";"
 526 ;
 527
 528 rhs:
 529   /* Nothing.  */
 530     { grammar_current_rule_begin (current_lhs, current_lhs_location); }
 531 | rhs symbol
 532     { grammar_current_rule_symbol_append ($2, @2); }
 533 | rhs "{...}"
 534     { grammar_current_rule_action_append ($2, @2); }
 535 | rhs "%prec" symbol
 536     { grammar_current_rule_prec_set ($3, @3); }
 537 | rhs "%dprec" INT
 538     { grammar_current_rule_dprec_set ($3, @3); }
 539 | rhs "%merge" TYPE
 540     { grammar_current_rule_merge_set ($3, @3); }
 541 ;
 542
 543
 544 /*---------------------------.
 545 | variable and content.opt.  |
 546 `---------------------------*/
 547
 548 variable:
 549   ID
 550 | STRING { $$ = uniqstr_new ($1); } /* deprecated and not M4-friendly */
 551 ;
 552
 553 /* Some content or empty by default. */
 554 content.opt:
 555   /* Nothing. */
 556     {
 557       $$ = "";
 558     }
 559 | STRING
 560 ;
 561
 562
 563 /*------------.
 564 | braceless.  |
 565 `------------*/
 566
 567 braceless:
 568   "{...}"
 569     {
 570       code_props plain_code;
 571       $1[strlen ($1) - 1] = '\n';
 572       code_props_plain_init (&plain_code, $1+1, @1);
 573       code_props_translate_code (&plain_code);
 574       gram_scanner_last_string_free ();
 575       $$ = plain_code.code;
 576     }
 577 ;
 578
 579
 580 /*--------------.
 581 | Identifiers.  |
 582 `--------------*/
 583
 584 /* Identifiers are returned as uniqstr values by the scanner.
 585    Depending on their use, we may need to make them genuine symbols.  */
 586
 587 id:
 588   ID
 589     { $$ = symbol_from_uniqstr ($1, @1); }
 590 | CHAR
 591     {
 592       $$ = symbol_get (char_name ($1), @1);
 593       symbol_class_set ($$, token_sym, @1, false);
 594       symbol_user_token_number_set ($$, $1, @1);
 595     }
 596 ;
 597
 598 id_colon:
 599   ID_COLON { $$ = symbol_from_uniqstr ($1, @1); }
 600 ;
 601
 602
 603 symbol:
 604   id
 605 | string_as_id
 606 ;
 607
 608 /* A string used as an ID: quote it.  */
 609 string_as_id:
 610   STRING
 611     {
 612       $$ = symbol_get (quotearg_style (c_quoting_style, $1), @1);
 613       symbol_class_set ($$, token_sym, @1, false);
 614     }
 615 ;
 616
 617 epilogue.opt:
 618   /* Nothing.  */
 619 | "%%" EPILOGUE
 620     {
 621       code_props plain_code;
 622       code_props_plain_init (&plain_code, $2, @2);
 623       code_props_translate_code (&plain_code);
 624       gram_scanner_last_string_free ();
 625       muscle_code_grow ("epilogue", plain_code.code, @2);
 626       code_scanner_last_string_free ();
 627     }
 628 ;
 629
 630 %%
 631
 632
 633 /* Return the location of the left-hand side of a rule whose
 634    right-hand side is RHS[1] ... RHS[N].  Ignore empty nonterminals in
 635    the right-hand side, and return an empty location equal to the end
 636    boundary of RHS[0] if the right-hand side is empty.  */
 637
 638 static YYLTYPE
 639 lloc_default (YYLTYPE const *rhs, int n)
 640 {
 641   int i;
 642   YYLTYPE loc;
 643
 644   /* SGI MIPSpro 7.4.1m miscompiles "loc.start = loc.end = rhs[n].end;".
 645      The bug is fixed in 7.4.2m, but play it safe for now.  */
 646   loc.start = rhs[n].end;
 647   loc.end = rhs[n].end;
 648
 649   /* Ignore empty nonterminals the start of the the right-hand side.
 650      Do not bother to ignore them at the end of the right-hand side,
 651      since empty nonterminals have the same end as their predecessors.  */
 652   for (i = 1; i <= n; i++)
 653     if (! equal_boundaries (rhs[i].start, rhs[i].end))
 654       {
 655         loc.start = rhs[i].start;
 656         break;
 657       }
 658
 659   return loc;
 660 }
 661
 662
 663 /* Add a lex-param or a parse-param (depending on TYPE) with
 664    declaration DECL and location LOC.  */
 665
 666 static void
 667 add_param (char const *type, char *decl, location loc)
 668 {
 669   static char const alphanum[26 + 26 + 1 + 10] =
 670     "abcdefghijklmnopqrstuvwxyz"
 671     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 672     "_"
 673     "0123456789";
 674   char const *name_start = NULL;
 675   char *p;
 676
 677   /* Stop on last actual character.  */
 678   for (p = decl; p[1]; p++)
 679     if ((p == decl
 680          || ! memchr (alphanum, p[-1], sizeof alphanum))
 681         && memchr (alphanum, p[0], sizeof alphanum - 10))
 682       name_start = p;
 683
 684   /* Strip the surrounding '{' and '}', and any blanks just inside
 685      the braces.  */
 686   while (*--p == ' ' || *p == '\t')
 687     continue;
 688   p[1] = '\0';
 689   while (*++decl == ' ' || *decl == '\t')
 690     continue;
 691
 692   if (! name_start)
 693     complain_at (loc, _("missing identifier in parameter declaration"));
 694   else
 695     {
 696       char *name;
 697       size_t name_len;
 698
 699       for (name_len = 1;
 700            memchr (alphanum, name_start[name_len], sizeof alphanum);
 701            name_len++)
 702         continue;
 703
 704       name = xmalloc (name_len + 1);
 705       memcpy (name, name_start, name_len);
 706       name[name_len] = '\0';
 707       muscle_pair_list_grow (type, decl, name);
 708       free (name);
 709     }
 710
 711   gram_scanner_last_string_free ();
 712 }
 713
 714
 715 static void
 716 version_check (location const *loc, char const *version)
 717 {
 718   if (strverscmp (version, PACKAGE_VERSION) > 0)
 719     {
 720       complain_at (*loc, "require bison %s, but have %s",
 721                    version, PACKAGE_VERSION);
 722       exit (63);
 723     }
 724 }
 725
 726 static void
 727 gram_error (location const *loc, char const *msg)
 728 {
 729   complain_at (*loc, "%s", msg);
 730 }
 731
 732 char const *
 733 token_name (int type)
 734 {
 735   return yytname[YYTRANSLATE (type)];
 736 }
 737
 738 static char const *
 739 char_name (char c)
 740 {
 741   if (c == '\'')
 742     return "'\\''";
 743   else
 744     {
 745       char buf[4];
 746       buf[0] = '\''; buf[1] = c; buf[2] = '\''; buf[3] = '\0';
 747       return quotearg_style (escape_quoting_style, buf);
 748     }
 749 }