src/parse-gram.y

   1 %{/* Bison Grammar Parser                             -*- C -*-
   2
   3    Copyright (C) 2002-2012 Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   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 #include <config.h>
  21 #include "system.h"
  22
  23 #include "complain.h"
  24 #include "conflicts.h"
  25 #include "files.h"
  26 #include "getargs.h"
  27 #include "gram.h"
  28 #include "muscle-tab.h"
  29 #include "named-ref.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
  54 %code
  55 {
  56   static int current_prec = 0;
  57   static location current_lhs_location;
  58   static named_ref *current_lhs_named_ref;
  59   static symbol *current_lhs_symbol;
  60   static symbol_class current_class = unknown_sym;
  61   static uniqstr current_type = NULL;
  62
  63   /** Set the new current left-hand side symbol, possibly common
  64    * to several right-hand side parts of rule.
  65    */
  66   static
  67   void
  68   current_lhs(symbol *sym, location loc, named_ref *ref)
  69   {
  70     current_lhs_symbol = sym;
  71     current_lhs_location = loc;
  72     /* In order to simplify memory management, named references for lhs
  73        are always assigned by deep copy into the current symbol_list
  74        node.  This is because a single named-ref in the grammar may
  75        result in several uses when the user factors lhs between several
  76        rules using "|".  Therefore free the parser's original copy.  */
  77     free (current_lhs_named_ref);
  78     current_lhs_named_ref = ref;
  79   }
  80
  81   #define YYTYPE_INT16 int_fast16_t
  82   #define YYTYPE_INT8 int_fast8_t
  83   #define YYTYPE_UINT16 uint_fast16_t
  84   #define YYTYPE_UINT8 uint_fast8_t
  85 }
  86
  87 %debug
  88 %verbose
  89 %defines
  90 %locations
  91 %pure-parser
  92 %define parse.error "verbose"
  93 %define parse.lac full
  94 %name-prefix="gram_"
  95 %expect 0
  96
  97 %initial-action
  98 {
  99   /* Bison's grammar can initial empty locations, hence a default
 100      location is needed. */
 101   boundary_set (&@$.start, current_file, 1, 1);
 102   boundary_set (&@$.end, current_file, 1, 1);
 103 }
 104
 105 %union
 106 {
 107   assoc assoc;
 108   char *code;
 109   char const *chars;
 110   int integer;
 111   named_ref *named_ref;
 112   symbol *symbol;
 113   symbol_list *list;
 114   uniqstr uniqstr;
 115   unsigned char character;
 116 };
 117
 118 /* Define the tokens together with their human representation.  */
 119 %token GRAM_EOF 0 "end of file"
 120 %token STRING     "string"
 121 %token INT        "integer"
 122
 123 %token PERCENT_TOKEN       "%token"
 124 %token PERCENT_NTERM       "%nterm"
 125
 126 %token PERCENT_TYPE        "%type"
 127 %token PERCENT_DESTRUCTOR  "%destructor"
 128 %token PERCENT_PRINTER     "%printer"
 129
 130 %token PERCENT_LEFT        "%left"
 131 %token PERCENT_RIGHT       "%right"
 132 %token PERCENT_NONASSOC    "%nonassoc"
 133 %token PERCENT_PRECEDENCE  "%precedence"
 134
 135 %token PERCENT_PREC          "%prec"
 136 %token PERCENT_DPREC         "%dprec"
 137 %token PERCENT_MERGE         "%merge"
 138
 139 /*----------------------.
 140 | Global Declarations.  |
 141 `----------------------*/
 142
 143 %token
 144   PERCENT_CODE            "%code"
 145   PERCENT_DEFAULT_PREC    "%default-prec"
 146   PERCENT_DEFINE          "%define"
 147   PERCENT_DEFINES         "%defines"
 148   PERCENT_ERROR_VERBOSE   "%error-verbose"
 149   PERCENT_EXPECT          "%expect"
 150   PERCENT_EXPECT_RR       "%expect-rr"
 151   PERCENT_FLAG            "%<flag>"
 152   PERCENT_FILE_PREFIX     "%file-prefix"
 153   PERCENT_GLR_PARSER      "%glr-parser"
 154   PERCENT_INITIAL_ACTION  "%initial-action"
 155   PERCENT_LANGUAGE        "%language"
 156   PERCENT_NAME_PREFIX     "%name-prefix"
 157   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
 158   PERCENT_NO_LINES        "%no-lines"
 159   PERCENT_NONDETERMINISTIC_PARSER
 160                           "%nondeterministic-parser"
 161   PERCENT_OUTPUT          "%output"
 162   PERCENT_REQUIRE         "%require"
 163   PERCENT_SKELETON        "%skeleton"
 164   PERCENT_START           "%start"
 165   PERCENT_TOKEN_TABLE     "%token-table"
 166   PERCENT_VERBOSE         "%verbose"
 167   PERCENT_YACC            "%yacc"
 168 ;
 169
 170 %token BRACED_CODE     "{...}"
 171 %token BRACED_PREDICATE "%?{...}"
 172 %token BRACKETED_ID    "[identifier]"
 173 %token CHAR            "char"
 174 %token EPILOGUE        "epilogue"
 175 %token EQUAL           "="
 176 %token ID              "identifier"
 177 %token ID_COLON        "identifier:"
 178 %token PERCENT_PERCENT "%%"
 179 %token PIPE            "|"
 180 %token PROLOGUE        "%{...%}"
 181 %token SEMICOLON       ";"
 182 %token TAG             "<tag>"
 183 %token TAG_ANY         "<*>"
 184 %token TAG_NONE        "<>"
 185
 186 %type <character> CHAR
 187 %printer { fputs (char_name ($$), stderr); } CHAR
 188
 189 /* braceless is not to be used for rule or symbol actions, as it
 190    calls code_props_plain_init.  */
 191 %type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
 192 %type <code> "{...}" "%?{...}"
 193 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
 194          STRING
 195 %printer { fprintf (stderr, "{\n%s\n}", $$); }
 196          braceless content.opt "{...}" "%{...%}" EPILOGUE
 197
 198 %type <uniqstr> BRACKETED_ID ID ID_COLON PERCENT_FLAG TAG variable
 199 %printer { fputs ($$, stderr); } <uniqstr>
 200 %printer { fprintf (stderr, "[%s]", $$); } BRACKETED_ID
 201 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
 202 %printer { fprintf (stderr, "%%%s", $$); } PERCENT_FLAG
 203 %printer { fprintf (stderr, "<%s>", $$); } TAG
 204
 205 %type <integer> INT
 206 %printer { fprintf (stderr, "%d", $$); } <integer>
 207
 208 %type <symbol> id id_colon string_as_id symbol symbol.prec
 209 %printer { fprintf (stderr, "%s", $$->tag); } <symbol>
 210 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 211
 212 %type <assoc> precedence_declarator
 213 %type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
 214 %type <named_ref> named_ref.opt
 215
 216 /*---------.
 217 | %param.  |
 218 `---------*/
 219 %code requires
 220 {
 221 # ifndef PARAM_TYPE
 222 #  define PARAM_TYPE
 223   typedef enum
 224   {
 225     param_none   = 0,
 226     param_lex    = 1 << 0,
 227     param_parse  = 1 << 1,
 228     param_both   = param_lex | param_parse
 229   } param_type;
 230 # endif
 231 };
 232 %code
 233 {
 234   /** Add a lex-param and/or a parse-param.
 235    *
 236    * \param type  where to push this formal argument.
 237    * \param decl  the formal argument.  Destroyed.
 238    * \param loc   the location in the source.
 239    */
 240   static void add_param (param_type type, char *decl, location loc);
 241   static param_type current_param = param_none;
 242 };
 243 %union
 244 {
 245   param_type param;
 246 }
 247 %token <param> PERCENT_PARAM "%param";
 248 %printer
 249 {
 250   switch ($$)
 251     {
 252 #define CASE(In, Out)                                           \
 253       case param_ ## In: fputs ("%" #Out, stderr); break
 254       CASE(lex,   lex-param);
 255       CASE(parse, parse-param);
 256       CASE(both,  param);
 257 #undef CASE
 258       case param_none: aver (false); break;
 259     }
 260 } <param>;
 261
 262
 263                      /*==========\
 264                      | Grammar.  |
 265                      \==========*/
 266 %%
 267
 268 input:
 269   prologue_declarations "%%" grammar epilogue.opt
 270 ;
 271
 272
 273         /*------------------------------------.
 274         | Declarations: before the first %%.  |
 275         `------------------------------------*/
 276
 277 prologue_declarations:
 278   /* Nothing */
 279 | prologue_declarations prologue_declaration
 280 ;
 281
 282 prologue_declaration:
 283   grammar_declaration
 284 | "%{...%}"
 285     {
 286       code_props plain_code;
 287       code_props_plain_init (&plain_code, $1, @1);
 288       code_props_translate_code (&plain_code);
 289       gram_scanner_last_string_free ();
 290       muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
 291                         plain_code.code, @1);
 292       code_scanner_last_string_free ();
 293     }
 294 | "%<flag>"
 295     {
 296       muscle_percent_define_ensure ($1, @1, true);
 297     }
 298 | "%define" variable content.opt
 299     {
 300       muscle_percent_define_insert ($2, @2, $3,
 301                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 302     }
 303 | "%defines"                       { defines_flag = true; }
 304 | "%defines" STRING
 305     {
 306       defines_flag = true;
 307       spec_defines_file = xstrdup ($2);
 308     }
 309 | "%error-verbose"
 310     {
 311       muscle_percent_define_insert ("parse.error", @1, "verbose",
 312                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 313     }
 314 | "%expect" INT                    { expected_sr_conflicts = $2; }
 315 | "%expect-rr" INT                 { expected_rr_conflicts = $2; }
 316 | "%file-prefix" STRING            { spec_file_prefix = $2; }
 317 | "%file-prefix" "=" STRING        { spec_file_prefix = $3; } /* deprecated */
 318 | "%glr-parser"
 319     {
 320       nondeterministic_parser = true;
 321       glr_parser = true;
 322     }
 323 | "%initial-action" "{...}"
 324     {
 325       code_props action;
 326       code_props_symbol_action_init (&action, $2, @2);
 327       code_props_translate_code (&action);
 328       gram_scanner_last_string_free ();
 329       muscle_code_grow ("initial_action", action.code, @2);
 330       code_scanner_last_string_free ();
 331     }
 332 | "%language" STRING            { language_argmatch ($2, grammar_prio, @1); }
 333 | "%name-prefix" STRING         { spec_name_prefix = $2; }
 334 | "%name-prefix" "=" STRING     { spec_name_prefix = $3; } /* deprecated */
 335 | "%no-lines"                   { no_lines_flag = true; }
 336 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 337 | "%output" STRING              { spec_outfile = $2; }
 338 | "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
 339 | "%param" { current_param = $1; } params { current_param = param_none; }
 340 | "%require" STRING             { version_check (&@2, $2); }
 341 | "%skeleton" STRING
 342     {
 343       char const *skeleton_user = $2;
 344       if (mbschr (skeleton_user, '/'))
 345         {
 346           size_t dir_length = strlen (current_file);
 347           char *skeleton_build;
 348           while (dir_length && current_file[dir_length - 1] != '/')
 349             --dir_length;
 350           while (dir_length && current_file[dir_length - 1] == '/')
 351             --dir_length;
 352           skeleton_build =
 353             xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
 354           if (dir_length > 0)
 355             {
 356               strncpy (skeleton_build, current_file, dir_length);
 357               skeleton_build[dir_length++] = '/';
 358             }
 359           strcpy (skeleton_build + dir_length, skeleton_user);
 360           skeleton_user = uniqstr_new (skeleton_build);
 361           free (skeleton_build);
 362         }
 363       skeleton_arg (skeleton_user, grammar_prio, @1);
 364     }
 365 | "%token-table"                { token_table_flag = true; }
 366 | "%verbose"                    { report_flag |= report_states; }
 367 | "%yacc"                       { yacc_flag = true; }
 368 | /*FIXME: Err?  What is this horror doing here? */ ";"
 369 ;
 370
 371 params:
 372    params "{...}"  { add_param (current_param, $2, @2); }
 373 | "{...}"          { add_param (current_param, $1, @1); }
 374 ;
 375
 376
 377 /*----------------------.
 378 | grammar_declaration.  |
 379 `----------------------*/
 380
 381 grammar_declaration:
 382   precedence_declaration
 383 | symbol_declaration
 384 | "%start" symbol
 385     {
 386       grammar_start_symbol_set ($2, @2);
 387     }
 388 | "%destructor" "{...}" generic_symlist
 389     {
 390       symbol_list *list;
 391       for (list = $3; list; list = list->next)
 392         symbol_list_destructor_set (list, $2, @2);
 393       symbol_list_free ($3);
 394     }
 395 | "%printer" "{...}" generic_symlist
 396     {
 397       symbol_list *list;
 398       for (list = $3; list; list = list->next)
 399         symbol_list_printer_set (list, $2, @2);
 400       symbol_list_free ($3);
 401     }
 402 | "%default-prec"
 403     {
 404       default_prec = true;
 405     }
 406 | "%no-default-prec"
 407     {
 408       default_prec = false;
 409     }
 410 | "%code" braceless
 411     {
 412       /* Do not invoke muscle_percent_code_grow here since it invokes
 413          muscle_user_name_list_grow.  */
 414       muscle_code_grow ("percent_code()", $2, @2);
 415       code_scanner_last_string_free ();
 416     }
 417 | "%code" ID braceless
 418     {
 419       muscle_percent_code_grow ($2, @2, $3, @3);
 420       code_scanner_last_string_free ();
 421     }
 422 ;
 423
 424
 425 /*---------.
 426 | %union.  |
 427 `---------*/
 428
 429 %token PERCENT_UNION "%union";
 430
 431 union_name:
 432   /* Nothing. */ {}
 433 | ID             { muscle_code_grow ("union_name", $1, @1); }
 434 ;
 435
 436 grammar_declaration:
 437   "%union" union_name braceless
 438     {
 439       union_seen = true;
 440       muscle_code_grow ("stype", $3, @3);
 441       code_scanner_last_string_free ();
 442     }
 443 ;
 444
 445
 446
 447
 448 symbol_declaration:
 449   "%nterm" { current_class = nterm_sym; } symbol_defs.1
 450     {
 451       current_class = unknown_sym;
 452       current_type = NULL;
 453     }
 454 | "%token" { current_class = token_sym; } symbol_defs.1
 455     {
 456       current_class = unknown_sym;
 457       current_type = NULL;
 458     }
 459 | "%type" TAG symbols.1
 460     {
 461       symbol_list *list;
 462       tag_seen = true;
 463       for (list = $3; list; list = list->next)
 464         symbol_type_set (list->content.sym, $2, @2);
 465       symbol_list_free ($3);
 466     }
 467 ;
 468
 469 precedence_declaration:
 470   precedence_declarator tag.opt symbols.prec
 471     {
 472       symbol_list *list;
 473       ++current_prec;
 474       for (list = $3; list; list = list->next)
 475         {
 476           symbol_type_set (list->content.sym, current_type, @2);
 477           symbol_precedence_set (list->content.sym, current_prec, $1, @1);
 478         }
 479       symbol_list_free ($3);
 480       current_type = NULL;
 481     }
 482 ;
 483
 484 precedence_declarator:
 485   "%left"       { $$ = left_assoc; }
 486 | "%right"      { $$ = right_assoc; }
 487 | "%nonassoc"   { $$ = non_assoc; }
 488 | "%precedence" { $$ = precedence_assoc; }
 489 ;
 490
 491 tag.opt:
 492   /* Nothing. */ { current_type = NULL; }
 493 | TAG            { current_type = $1; tag_seen = true; }
 494 ;
 495
 496 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
 497 symbols.prec:
 498   symbol.prec
 499     { $$ = symbol_list_sym_new ($1, @1); }
 500 | symbols.prec symbol.prec
 501     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 502 ;
 503
 504 symbol.prec:
 505     symbol { $$ = $1; }
 506   | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
 507   ;
 508
 509 /* One or more symbols to be %typed. */
 510 symbols.1:
 511   symbol
 512     { $$ = symbol_list_sym_new ($1, @1); }
 513 | symbols.1 symbol
 514     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 515 ;
 516
 517 generic_symlist:
 518   generic_symlist_item { $$ = $1; }
 519 | generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
 520 ;
 521
 522 generic_symlist_item:
 523   symbol    { $$ = symbol_list_sym_new ($1, @1); }
 524 | TAG       { $$ = symbol_list_type_new ($1, @1); }
 525 | "<*>"     { $$ = symbol_list_default_tagged_new (@1); }
 526 | "<>"      { $$ = symbol_list_default_tagless_new (@1); }
 527 ;
 528
 529 /* One token definition.  */
 530 symbol_def:
 531   TAG
 532      {
 533        current_type = $1;
 534        tag_seen = true;
 535      }
 536 | id
 537      {
 538        symbol_class_set ($1, current_class, @1, true);
 539        symbol_type_set ($1, current_type, @1);
 540      }
 541 | id INT
 542     {
 543       symbol_class_set ($1, current_class, @1, true);
 544       symbol_type_set ($1, current_type, @1);
 545       symbol_user_token_number_set ($1, $2, @2);
 546     }
 547 | id string_as_id
 548     {
 549       symbol_class_set ($1, current_class, @1, true);
 550       symbol_type_set ($1, current_type, @1);
 551       symbol_make_alias ($1, $2, @$);
 552     }
 553 | id INT string_as_id
 554     {
 555       symbol_class_set ($1, current_class, @1, true);
 556       symbol_type_set ($1, current_type, @1);
 557       symbol_user_token_number_set ($1, $2, @2);
 558       symbol_make_alias ($1, $3, @$);
 559     }
 560 ;
 561
 562 /* One or more symbol definitions. */
 563 symbol_defs.1:
 564   symbol_def
 565 | symbol_defs.1 symbol_def
 566 ;
 567
 568
 569         /*------------------------------------------.
 570         | The grammar section: between the two %%.  |
 571         `------------------------------------------*/
 572
 573 grammar:
 574   rules_or_grammar_declaration
 575 | grammar rules_or_grammar_declaration
 576 ;
 577
 578 /* As a Bison extension, one can use the grammar declarations in the
 579    body of the grammar.  */
 580 rules_or_grammar_declaration:
 581   rules
 582 | grammar_declaration ";"
 583 | error ";"
 584     {
 585       yyerrok;
 586     }
 587 ;
 588
 589 rules:
 590   id_colon named_ref.opt { current_lhs ($1, @1, $2); } rhses.1
 591   {
 592     /* Free the current lhs. */
 593     current_lhs (0, @1, 0);
 594   }
 595 ;
 596
 597 rhses.1:
 598   rhs                { grammar_current_rule_end (@1); }
 599 | rhses.1 "|" rhs    { grammar_current_rule_end (@3); }
 600 | rhses.1 ";"
 601 ;
 602
 603 rhs:
 604   /* Nothing.  */
 605     { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location,
 606                                   current_lhs_named_ref); }
 607 | rhs symbol named_ref.opt
 608     { grammar_current_rule_symbol_append ($2, @2, $3); }
 609 | rhs "{...}" named_ref.opt
 610     { grammar_current_rule_action_append ($2, @2, $3, false); }
 611 | rhs "%?{...}"
 612     { grammar_current_rule_action_append ($2, @2, NULL, true); }
 613 | rhs "%prec" symbol
 614     { grammar_current_rule_prec_set ($3, @3); }
 615 | rhs "%dprec" INT
 616     { grammar_current_rule_dprec_set ($3, @3); }
 617 | rhs "%merge" TAG
 618     { grammar_current_rule_merge_set ($3, @3); }
 619 ;
 620
 621 named_ref.opt:
 622   /* Nothing. */ { $$ = 0; }
 623 |
 624   BRACKETED_ID   { $$ = named_ref_new($1, @1); }
 625 ;
 626
 627 /*---------------------------.
 628 | variable and content.opt.  |
 629 `---------------------------*/
 630
 631 /* The STRING form of variable is deprecated and is not M4-friendly.
 632    For example, M4 fails for `%define "[" "value"'.  */
 633 variable:
 634   ID
 635 | STRING { $$ = uniqstr_new ($1); }
 636 ;
 637
 638 /* Some content or empty by default. */
 639 content.opt:
 640   /* Nothing. */   { $$ = ""; }
 641 | ID { $$ = $1; }
 642 | STRING
 643 ;
 644
 645
 646 /*------------.
 647 | braceless.  |
 648 `------------*/
 649
 650 braceless:
 651   "{...}"
 652     {
 653       code_props plain_code;
 654       $1[strlen ($1) - 1] = '\n';
 655       code_props_plain_init (&plain_code, $1+1, @1);
 656       code_props_translate_code (&plain_code);
 657       gram_scanner_last_string_free ();
 658       $$ = plain_code.code;
 659     }
 660 ;
 661
 662
 663 /*--------------.
 664 | Identifiers.  |
 665 `--------------*/
 666
 667 /* Identifiers are returned as uniqstr values by the scanner.
 668    Depending on their use, we may need to make them genuine symbols.  */
 669
 670 id:
 671   ID
 672     { $$ = symbol_from_uniqstr ($1, @1); }
 673 | CHAR
 674     {
 675       $$ = symbol_get (char_name ($1), @1);
 676       symbol_class_set ($$, token_sym, @1, false);
 677       symbol_user_token_number_set ($$, $1, @1);
 678     }
 679 ;
 680
 681 id_colon:
 682   ID_COLON { $$ = symbol_from_uniqstr ($1, @1); }
 683 ;
 684
 685
 686 symbol:
 687   id
 688 | string_as_id
 689 ;
 690
 691 /* A string used as an ID: quote it.  */
 692 string_as_id:
 693   STRING
 694     {
 695       $$ = symbol_get (quotearg_style (c_quoting_style, $1), @1);
 696       symbol_class_set ($$, token_sym, @1, false);
 697     }
 698 ;
 699
 700 epilogue.opt:
 701   /* Nothing.  */
 702 | "%%" EPILOGUE
 703     {
 704       code_props plain_code;
 705       code_props_plain_init (&plain_code, $2, @2);
 706       code_props_translate_code (&plain_code);
 707       gram_scanner_last_string_free ();
 708       muscle_code_grow ("epilogue", plain_code.code, @2);
 709       code_scanner_last_string_free ();
 710     }
 711 ;
 712
 713 %%
 714
 715
 716 /* Return the location of the left-hand side of a rule whose
 717    right-hand side is RHS[1] ... RHS[N].  Ignore empty nonterminals in
 718    the right-hand side, and return an empty location equal to the end
 719    boundary of RHS[0] if the right-hand side is empty.  */
 720
 721 static YYLTYPE
 722 lloc_default (YYLTYPE const *rhs, int n)
 723 {
 724   int i;
 725   YYLTYPE loc;
 726
 727   /* SGI MIPSpro 7.4.1m miscompiles "loc.start = loc.end = rhs[n].end;".
 728      The bug is fixed in 7.4.2m, but play it safe for now.  */
 729   loc.start = rhs[n].end;
 730   loc.end = rhs[n].end;
 731
 732   /* Ignore empty nonterminals the start of the right-hand side.
 733      Do not bother to ignore them at the end of the right-hand side,
 734      since empty nonterminals have the same end as their predecessors.  */
 735   for (i = 1; i <= n; i++)
 736     if (! equal_boundaries (rhs[i].start, rhs[i].end))
 737       {
 738         loc.start = rhs[i].start;
 739         break;
 740       }
 741
 742   return loc;
 743 }
 744
 745
 746 static void
 747 add_param (param_type type, char *decl, location loc)
 748 {
 749   static char const alphanum[26 + 26 + 1 + 10] =
 750     "abcdefghijklmnopqrstuvwxyz"
 751     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 752     "_"
 753     "0123456789";
 754
 755   char const *name_start = NULL;
 756   {
 757     char *p;
 758     /* Stop on last actual character.  */
 759     for (p = decl; p[1]; p++)
 760       if ((p == decl
 761            || ! memchr (alphanum, p[-1], sizeof alphanum))
 762           && memchr (alphanum, p[0], sizeof alphanum - 10))
 763         name_start = p;
 764
 765     /* Strip the surrounding '{' and '}', and any blanks just inside
 766        the braces.  */
 767     while (*--p == ' ' || *p == '\t')
 768       continue;
 769     p[1] = '\0';
 770     while (*++decl == ' ' || *decl == '\t')
 771       continue;
 772   }
 773
 774   if (! name_start)
 775     complain_at (loc, _("missing identifier in parameter declaration"));
 776   else
 777     {
 778       char *name;
 779       size_t name_len;
 780
 781       for (name_len = 1;
 782            memchr (alphanum, name_start[name_len], sizeof alphanum);
 783            name_len++)
 784         continue;
 785
 786       name = xmalloc (name_len + 1);
 787       memcpy (name, name_start, name_len);
 788       name[name_len] = '\0';
 789       if (type & param_lex)
 790         muscle_pair_list_grow ("lex_param", decl, name);
 791       if (type & param_parse)
 792         muscle_pair_list_grow ("parse_param", decl, name);
 793       free (name);
 794     }
 795
 796   gram_scanner_last_string_free ();
 797 }
 798
 799
 800 static void
 801 version_check (location const *loc, char const *version)
 802 {
 803   if (strverscmp (version, PACKAGE_VERSION) > 0)
 804     {
 805       complain_at (*loc, "require bison %s, but have %s",
 806                    version, PACKAGE_VERSION);
 807       exit (EX_MISMATCH);
 808     }
 809 }
 810
 811 static void
 812 gram_error (location const *loc, char const *msg)
 813 {
 814   complain_at (*loc, "%s", msg);
 815 }
 816
 817 char const *
 818 token_name (int type)
 819 {
 820   return yytname[YYTRANSLATE (type)];
 821 }
 822
 823 static char const *
 824 char_name (char c)
 825 {
 826   if (c == '\'')
 827     return "'\\''";
 828   else
 829     {
 830       char buf[4];
 831       buf[0] = '\''; buf[1] = c; buf[2] = '\''; buf[3] = '\0';
 832       return quotearg_style (escape_quoting_style, buf);
 833     }
 834 }