src/parse-gram.y

   1 /* Bison Grammar Parser                             -*- C -*-
   2
   3    Copyright (C) 2002-2013 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 %code requires
  21 {
  22   #include "symlist.h"
  23   #include "symtab.h"
  24 }
  25
  26 %code
  27 {
  28   #include <config.h>
  29   #include "system.h"
  30
  31   #include "c-ctype.h"
  32   #include "complain.h"
  33   #include "conflicts.h"
  34   #include "files.h"
  35   #include "getargs.h"
  36   #include "gram.h"
  37   #include "named-ref.h"
  38   #include "quotearg.h"
  39   #include "reader.h"
  40   #include "scan-gram.h"
  41   #include "scan-code.h"
  42   #include "xmemdup0.h"
  43
  44   static int current_prec = 0;
  45   static location current_lhs_location;
  46   static named_ref *current_lhs_named_ref;
  47   static symbol *current_lhs_symbol;
  48   static symbol_class current_class = unknown_sym;
  49   static uniqstr current_type = NULL;
  50
  51   /** Set the new current left-hand side symbol, possibly common
  52    * to several right-hand side parts of rule.
  53    */
  54   static void current_lhs (symbol *sym, location loc, named_ref *ref);
  55
  56   #define YYLLOC_DEFAULT(Current, Rhs, N)         \
  57     (Current) = lloc_default (Rhs, N)
  58   static YYLTYPE lloc_default (YYLTYPE const *, int);
  59
  60   #define YY_LOCATION_PRINT(File, Loc)            \
  61     location_print (Loc, File)
  62
  63   /* Strip initial '{' and final '}' (must be first and last characters).
  64      Return the result.  */
  65   static char *strip_braces (char *code);
  66
  67   /* Convert CODE by calling code_props_plain_init if PLAIN, otherwise
  68      code_props_symbol_action_init.  Call
  69      gram_scanner_last_string_free to release the latest string from
  70      the scanner (should be CODE). */
  71   static char const *translate_code (char *code, location loc, bool plain);
  72
  73   /* Convert CODE by calling code_props_plain_init after having
  74      stripped the first and last characters (expected to be '{', and
  75      '}').  Call gram_scanner_last_string_free to release the latest
  76      string from the scanner (should be CODE). */
  77   static char const *translate_code_braceless (char *code, location loc);
  78
  79   static void version_check (location const *loc, char const *version);
  80
  81   static void gram_error (location const *, char const *);
  82
  83   /* A string that describes a char (e.g., 'a' -> "'a'").  */
  84   static char const *char_name (char);
  85
  86   #define YYTYPE_INT16 int_fast16_t
  87   #define YYTYPE_INT8 int_fast8_t
  88   #define YYTYPE_UINT16 uint_fast16_t
  89   #define YYTYPE_UINT8 uint_fast8_t
  90 }
  91
  92 %define api.prefix {gram_}
  93 %define api.pure full
  94 %define locations
  95 %define parse.error verbose
  96 %define parse.lac full
  97 %define parse.trace
  98 %defines
  99 %expect 0
 100 %verbose
 101
 102 %initial-action
 103 {
 104   /* Bison's grammar can initial empty locations, hence a default
 105      location is needed. */
 106   boundary_set (&@$.start, current_file, 1, 1);
 107   boundary_set (&@$.end, current_file, 1, 1);
 108 }
 109
 110 /* Define the tokens together with their human representation.  */
 111 %token GRAM_EOF 0 "end of file"
 112 %token STRING     "string"
 113
 114 %token PERCENT_TOKEN       "%token"
 115 %token PERCENT_NTERM       "%nterm"
 116
 117 %token PERCENT_TYPE        "%type"
 118 %token PERCENT_DESTRUCTOR  "%destructor"
 119 %token PERCENT_PRINTER     "%printer"
 120
 121 %token PERCENT_LEFT        "%left"
 122 %token PERCENT_RIGHT       "%right"
 123 %token PERCENT_NONASSOC    "%nonassoc"
 124 %token PERCENT_PRECEDENCE  "%precedence"
 125
 126 %token PERCENT_PREC          "%prec"
 127 %token PERCENT_DPREC         "%dprec"
 128 %token PERCENT_MERGE         "%merge"
 129
 130 /*----------------------.
 131 | Global Declarations.  |
 132 `----------------------*/
 133
 134 %token
 135   PERCENT_CODE            "%code"
 136   PERCENT_DEFAULT_PREC    "%default-prec"
 137   PERCENT_DEFINE          "%define"
 138   PERCENT_DEFINES         "%defines"
 139   PERCENT_ERROR_VERBOSE   "%error-verbose"
 140   PERCENT_EXPECT          "%expect"
 141   PERCENT_EXPECT_RR       "%expect-rr"
 142   PERCENT_FLAG            "%<flag>"
 143   PERCENT_FILE_PREFIX     "%file-prefix"
 144   PERCENT_GLR_PARSER      "%glr-parser"
 145   PERCENT_INITIAL_ACTION  "%initial-action"
 146   PERCENT_LANGUAGE        "%language"
 147   PERCENT_NAME_PREFIX     "%name-prefix"
 148   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
 149   PERCENT_NO_LINES        "%no-lines"
 150   PERCENT_NONDETERMINISTIC_PARSER
 151                           "%nondeterministic-parser"
 152   PERCENT_OUTPUT          "%output"
 153   PERCENT_REQUIRE         "%require"
 154   PERCENT_SKELETON        "%skeleton"
 155   PERCENT_START           "%start"
 156   PERCENT_TOKEN_TABLE     "%token-table"
 157   PERCENT_VERBOSE         "%verbose"
 158   PERCENT_YACC            "%yacc"
 159 ;
 160
 161 %token BRACED_CODE     "{...}"
 162 %token BRACED_PREDICATE "%?{...}"
 163 %token BRACKETED_ID    "[identifier]"
 164 %token CHAR            "char"
 165 %token EPILOGUE        "epilogue"
 166 %token EQUAL           "="
 167 %token ID              "identifier"
 168 %token ID_COLON        "identifier:"
 169 %token PERCENT_PERCENT "%%"
 170 %token PIPE            "|"
 171 %token PROLOGUE        "%{...%}"
 172 %token SEMICOLON       ";"
 173 %token TAG             "<tag>"
 174 %token TAG_ANY         "<*>"
 175 %token TAG_NONE        "<>"
 176
 177 %union {unsigned char character;}
 178 %type <character> CHAR
 179 %printer { fputs (char_name ($$), yyo); } CHAR
 180
 181 %union {char *code;};
 182 %type <code> "{...}" "%?{...}" "%{...%}" EPILOGUE STRING
 183 %printer { fputs (quotearg_style (c_quoting_style, $$), yyo); } STRING
 184 %printer { fprintf (yyo, "{\n%s\n}", $$); } <code>
 185
 186 %union {uniqstr uniqstr;}
 187 %type <uniqstr> BRACKETED_ID ID ID_COLON PERCENT_FLAG TAG tag variable
 188 %printer { fputs ($$, yyo); } <uniqstr>
 189 %printer { fprintf (yyo, "[%s]", $$); } BRACKETED_ID
 190 %printer { fprintf (yyo, "%s:", $$); } ID_COLON
 191 %printer { fprintf (yyo, "%%%s", $$); } PERCENT_FLAG
 192 %printer { fprintf (yyo, "<%s>", $$); } TAG tag
 193
 194 %union {int integer;};
 195 %token <integer> INT "integer"
 196 %printer { fprintf (yyo, "%d", $$); } <integer>
 197
 198 %union {symbol *symbol;}
 199 %type <symbol> id id_colon string_as_id symbol symbol.prec
 200 %printer { fprintf (yyo, "%s", $$->tag); } <symbol>
 201 %printer { fprintf (yyo, "%s:", $$->tag); } id_colon
 202
 203 %union {assoc assoc;};
 204 %type <assoc> precedence_declarator
 205
 206 %union {symbol_list *list;}
 207 %type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
 208
 209 %union {named_ref *named_ref;}
 210 %type <named_ref> named_ref.opt
 211
 212 /*---------.
 213 | %param.  |
 214 `---------*/
 215 %code requires
 216 {
 217   typedef enum
 218   {
 219     param_none   = 0,
 220     param_lex    = 1 << 0,
 221     param_parse  = 1 << 1,
 222     param_both   = param_lex | param_parse
 223   } param_type;
 224 };
 225 %code
 226 {
 227   /** Add a lex-param and/or a parse-param.
 228    *
 229    * \param type  where to push this formal argument.
 230    * \param decl  the formal argument.  Destroyed.
 231    * \param loc   the location in the source.
 232    */
 233   static void add_param (param_type type, char *decl, location loc);
 234   static param_type current_param = param_none;
 235 };
 236 %union {param_type param;}
 237 %token <param> PERCENT_PARAM "%param";
 238 %printer
 239 {
 240   switch ($$)
 241     {
 242 #define CASE(In, Out)                                           \
 243       case param_ ## In: fputs ("%" #Out, yyo); break
 244       CASE (lex,   lex-param);
 245       CASE (parse, parse-param);
 246       CASE (both,  param);
 247 #undef CASE
 248       case param_none: aver (false); break;
 249     }
 250 } <param>;
 251
 252
 253                      /*==========\
 254                      | Grammar.  |
 255                      \==========*/
 256 %%
 257
 258 input:
 259   prologue_declarations "%%" grammar epilogue.opt
 260 ;
 261
 262
 263         /*------------------------------------.
 264         | Declarations: before the first %%.  |
 265         `------------------------------------*/
 266
 267 prologue_declarations:
 268   %empty
 269 | prologue_declarations prologue_declaration
 270 ;
 271
 272 prologue_declaration:
 273   grammar_declaration
 274 | "%{...%}"
 275     {
 276       muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
 277                         translate_code ($1, @1, true), @1);
 278       code_scanner_last_string_free ();
 279     }
 280 | "%<flag>"
 281     {
 282       muscle_percent_define_ensure ($1, @1, true);
 283     }
 284 | "%define" variable value
 285     {
 286       muscle_percent_define_insert ($2, @2, $3.kind, $3.chars,
 287                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 288     }
 289 | "%defines"                       { defines_flag = true; }
 290 | "%defines" STRING
 291     {
 292       defines_flag = true;
 293       spec_defines_file = xstrdup ($2);
 294     }
 295 | "%error-verbose"
 296     {
 297       muscle_percent_define_insert ("parse.error", @1, muscle_keyword,
 298                                     "verbose",
 299                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 300     }
 301 | "%expect" INT                    { expected_sr_conflicts = $2; }
 302 | "%expect-rr" INT                 { expected_rr_conflicts = $2; }
 303 | "%file-prefix" STRING            { spec_file_prefix = $2; }
 304 | "%glr-parser"
 305     {
 306       nondeterministic_parser = true;
 307       glr_parser = true;
 308     }
 309 | "%initial-action" "{...}"
 310     {
 311       muscle_code_grow ("initial_action", translate_code ($2, @2, false), @2);
 312       code_scanner_last_string_free ();
 313     }
 314 | "%language" STRING            { language_argmatch ($2, grammar_prio, @1); }
 315 | "%name-prefix" STRING         { spec_name_prefix = $2; }
 316 | "%no-lines"                   { no_lines_flag = true; }
 317 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 318 | "%output" STRING              { spec_outfile = $2; }
 319 | "%param" { current_param = $1; } params { current_param = param_none; }
 320 | "%require" STRING             { version_check (&@2, $2); }
 321 | "%skeleton" STRING
 322     {
 323       char const *skeleton_user = $2;
 324       if (strchr (skeleton_user, '/'))
 325         {
 326           size_t dir_length = strlen (current_file);
 327           char *skeleton_build;
 328           while (dir_length && current_file[dir_length - 1] != '/')
 329             --dir_length;
 330           while (dir_length && current_file[dir_length - 1] == '/')
 331             --dir_length;
 332           skeleton_build =
 333             xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
 334           if (dir_length > 0)
 335             {
 336               memcpy (skeleton_build, current_file, dir_length);
 337               skeleton_build[dir_length++] = '/';
 338             }
 339           strcpy (skeleton_build + dir_length, skeleton_user);
 340           skeleton_user = uniqstr_new (skeleton_build);
 341           free (skeleton_build);
 342         }
 343       skeleton_arg (skeleton_user, grammar_prio, @1);
 344     }
 345 | "%token-table"                { token_table_flag = true; }
 346 | "%verbose"                    { report_flag |= report_states; }
 347 | "%yacc"                       { yacc_flag = true; }
 348 | /*FIXME: Err?  What is this horror doing here? */ ";"
 349 ;
 350
 351 params:
 352    params "{...}"  { add_param (current_param, $2, @2); }
 353 | "{...}"          { add_param (current_param, $1, @1); }
 354 ;
 355
 356
 357 /*----------------------.
 358 | grammar_declaration.  |
 359 `----------------------*/
 360
 361 grammar_declaration:
 362   precedence_declaration
 363 | symbol_declaration
 364 | "%start" symbol
 365     {
 366       grammar_start_symbol_set ($2, @2);
 367     }
 368 | code_props_type "{...}" generic_symlist
 369     {
 370       code_props code;
 371       code_props_symbol_action_init (&code, $2, @2);
 372       code_props_translate_code (&code);
 373       {
 374         symbol_list *list;
 375         for (list = $3; list; list = list->next)
 376           symbol_list_code_props_set (list, $1, &code);
 377         symbol_list_free ($3);
 378       }
 379     }
 380 | "%default-prec"
 381     {
 382       default_prec = true;
 383     }
 384 | "%no-default-prec"
 385     {
 386       default_prec = false;
 387     }
 388 | "%code" "{...}"
 389     {
 390       /* Do not invoke muscle_percent_code_grow here since it invokes
 391          muscle_user_name_list_grow.  */
 392       muscle_code_grow ("percent_code()",
 393                         translate_code_braceless ($2, @2), @2);
 394       code_scanner_last_string_free ();
 395     }
 396 | "%code" ID "{...}"
 397     {
 398       muscle_percent_code_grow ($2, @2, translate_code_braceless ($3, @3), @3);
 399       code_scanner_last_string_free ();
 400     }
 401 ;
 402
 403 %type <code_type> code_props_type;
 404 %union {code_props_type code_type;};
 405 %printer { fprintf (yyo, "%s", code_props_type_string ($$)); } <code_type>;
 406 code_props_type:
 407   "%destructor"  { $$ = destructor; }
 408 | "%printer"     { $$ = printer; }
 409 ;
 410
 411 /*---------.
 412 | %union.  |
 413 `---------*/
 414
 415 %token PERCENT_UNION "%union";
 416
 417 union_name:
 418   %empty {}
 419 | ID     { muscle_code_grow ("union_name", $1, @1); }
 420 ;
 421
 422 grammar_declaration:
 423   "%union" union_name "{...}"
 424     {
 425       union_seen = true;
 426       muscle_code_grow ("union_members", translate_code_braceless ($3, @3), @3);
 427       code_scanner_last_string_free ();
 428     }
 429 ;
 430
 431
 432
 433
 434 symbol_declaration:
 435   "%nterm" { current_class = nterm_sym; } symbol_defs.1
 436     {
 437       current_class = unknown_sym;
 438       current_type = NULL;
 439     }
 440 | "%token" { current_class = token_sym; } symbol_defs.1
 441     {
 442       current_class = unknown_sym;
 443       current_type = NULL;
 444     }
 445 | "%type" TAG symbols.1
 446     {
 447       symbol_list *list;
 448       tag_seen = true;
 449       for (list = $3; list; list = list->next)
 450         symbol_type_set (list->content.sym, $2, @2);
 451       symbol_list_free ($3);
 452     }
 453 ;
 454
 455 precedence_declaration:
 456   precedence_declarator tag.opt symbols.prec
 457     {
 458       symbol_list *list;
 459       ++current_prec;
 460       for (list = $3; list; list = list->next)
 461         {
 462           symbol_type_set (list->content.sym, current_type, @2);
 463           symbol_precedence_set (list->content.sym, current_prec, $1, @1);
 464         }
 465       symbol_list_free ($3);
 466       current_type = NULL;
 467     }
 468 ;
 469
 470 precedence_declarator:
 471   "%left"       { $$ = left_assoc; }
 472 | "%right"      { $$ = right_assoc; }
 473 | "%nonassoc"   { $$ = non_assoc; }
 474 | "%precedence" { $$ = precedence_assoc; }
 475 ;
 476
 477 tag.opt:
 478   %empty { current_type = NULL; }
 479 | TAG    { current_type = $1; tag_seen = true; }
 480 ;
 481
 482 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
 483 symbols.prec:
 484   symbol.prec
 485     { $$ = symbol_list_sym_new ($1, @1); }
 486 | symbols.prec symbol.prec
 487     { $$ = symbol_list_append ($1, symbol_list_sym_new ($2, @2)); }
 488 ;
 489
 490 symbol.prec:
 491   symbol
 492     {
 493       $$ = $1;
 494       symbol_class_set ($1, token_sym, @1, false);
 495     }
 496 | symbol INT
 497     {
 498       $$ = $1;
 499       symbol_user_token_number_set ($1, $2, @2);
 500       symbol_class_set ($1, token_sym, @1, false);
 501     }
 502 ;
 503
 504 /* One or more symbols to be %typed. */
 505 symbols.1:
 506   symbol
 507     { $$ = symbol_list_sym_new ($1, @1); }
 508 | symbols.1 symbol
 509     { $$ = symbol_list_append ($1, symbol_list_sym_new ($2, @2)); }
 510 ;
 511
 512 generic_symlist:
 513   generic_symlist_item { $$ = $1; }
 514 | generic_symlist generic_symlist_item { $$ = symbol_list_append ($1, $2); }
 515 ;
 516
 517 generic_symlist_item:
 518   symbol    { $$ = symbol_list_sym_new ($1, @1); }
 519 | tag       { $$ = symbol_list_type_new ($1, @1); }
 520 ;
 521
 522 tag:
 523   TAG
 524 | "<*>" { $$ = uniqstr_new ("*"); }
 525 | "<>"  { $$ = uniqstr_new (""); }
 526 ;
 527
 528 /* One token definition.  */
 529 symbol_def:
 530   TAG
 531     {
 532       current_type = $1;
 533       tag_seen = true;
 534     }
 535 | id
 536     {
 537       symbol_class_set ($1, current_class, @1, true);
 538       symbol_type_set ($1, current_type, @1);
 539     }
 540 | id INT
 541     {
 542       symbol_class_set ($1, current_class, @1, true);
 543       symbol_type_set ($1, current_type, @1);
 544       symbol_user_token_number_set ($1, $2, @2);
 545     }
 546 | id string_as_id
 547     {
 548       symbol_class_set ($1, current_class, @1, true);
 549       symbol_type_set ($1, current_type, @1);
 550       symbol_make_alias ($1, $2, @$);
 551     }
 552 | id INT string_as_id
 553     {
 554       symbol_class_set ($1, current_class, @1, true);
 555       symbol_type_set ($1, current_type, @1);
 556       symbol_user_token_number_set ($1, $2, @2);
 557       symbol_make_alias ($1, $3, @$);
 558     }
 559 ;
 560
 561 /* One or more symbol definitions. */
 562 symbol_defs.1:
 563   symbol_def
 564 | symbol_defs.1 symbol_def
 565 ;
 566
 567
 568         /*------------------------------------------.
 569         | The grammar section: between the two %%.  |
 570         `------------------------------------------*/
 571
 572 grammar:
 573   rules_or_grammar_declaration
 574 | grammar rules_or_grammar_declaration
 575 ;
 576
 577 /* As a Bison extension, one can use the grammar declarations in the
 578    body of the grammar.  */
 579 rules_or_grammar_declaration:
 580   rules
 581 | grammar_declaration ";"
 582 | error ";"
 583     {
 584       yyerrok;
 585     }
 586 ;
 587
 588 rules:
 589   id_colon named_ref.opt { current_lhs ($1, @1, $2); } rhses.1
 590   {
 591     /* Free the current lhs. */
 592     current_lhs (0, @1, 0);
 593   }
 594 ;
 595
 596 rhses.1:
 597   rhs                { grammar_current_rule_end (@1); }
 598 | rhses.1 "|" rhs    { grammar_current_rule_end (@3); }
 599 | rhses.1 ";"
 600 ;
 601
 602 %token PERCENT_EMPTY "%empty";
 603 rhs:
 604   %empty
 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 "%empty"
 614     { grammar_current_rule_empty_set (@2); }
 615 | rhs "%prec" symbol
 616     { grammar_current_rule_prec_set ($3, @3); }
 617 | rhs "%dprec" INT
 618     { grammar_current_rule_dprec_set ($3, @3); }
 619 | rhs "%merge" TAG
 620     { grammar_current_rule_merge_set ($3, @3); }
 621 ;
 622
 623 named_ref.opt:
 624   %empty         { $$ = 0; }
 625 | BRACKETED_ID   { $$ = named_ref_new($1, @1); }
 626 ;
 627
 628 /*---------------------.
 629 | variable and value.  |
 630 `---------------------*/
 631
 632 /* The STRING form of variable is deprecated and is not M4-friendly.
 633    For example, M4 fails for '%define "[" "value"'.  */
 634 variable:
 635   ID
 636 | STRING { $$ = uniqstr_new ($1); }
 637 ;
 638
 639 /* Some content or empty by default. */
 640 %code requires {#include "muscle-tab.h"};
 641 %union
 642 {
 643   struct
 644   {
 645     char const *chars;
 646     muscle_kind kind;
 647   } value;
 648 };
 649 %type <value> value;
 650 %printer
 651 {
 652   switch ($$.kind)
 653     {
 654     case muscle_code:    fprintf (yyo,  "{%s}",  $$.chars); break;
 655     case muscle_keyword: fprintf (yyo,   "%s",   $$.chars); break;
 656     case muscle_string:  fprintf (yyo, "\"%s\"", $$.chars); break;
 657     }
 658 } <value>;
 659
 660 value:
 661   %empty  { $$.kind = muscle_keyword; $$.chars = ""; }
 662 | ID      { $$.kind = muscle_keyword; $$.chars = $1; }
 663 | STRING  { $$.kind = muscle_string;  $$.chars = $1; }
 664 | "{...}" { $$.kind = muscle_code;    $$.chars = strip_braces ($1); }
 665 ;
 666
 667
 668 /*--------------.
 669 | Identifiers.  |
 670 `--------------*/
 671
 672 /* Identifiers are returned as uniqstr values by the scanner.
 673    Depending on their use, we may need to make them genuine symbols.  */
 674
 675 id:
 676   ID
 677     { $$ = symbol_from_uniqstr ($1, @1); }
 678 | CHAR
 679     {
 680       $$ = symbol_get (char_name ($1), @1);
 681       symbol_class_set ($$, token_sym, @1, false);
 682       symbol_user_token_number_set ($$, $1, @1);
 683     }
 684 ;
 685
 686 id_colon:
 687   ID_COLON { $$ = symbol_from_uniqstr ($1, @1); }
 688 ;
 689
 690
 691 symbol:
 692   id
 693 | string_as_id
 694 ;
 695
 696 /* A string used as an ID: quote it.  */
 697 string_as_id:
 698   STRING
 699     {
 700       $$ = symbol_get (quotearg_style (c_quoting_style, $1), @1);
 701       symbol_class_set ($$, token_sym, @1, false);
 702     }
 703 ;
 704
 705 epilogue.opt:
 706   %empty
 707 | "%%" EPILOGUE
 708     {
 709       muscle_code_grow ("epilogue", translate_code ($2, @2, true), @2);
 710       code_scanner_last_string_free ();
 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 static
 746 char *strip_braces (char *code)
 747 {
 748   code[strlen(code) - 1] = 0;
 749   return code + 1;
 750 }
 751
 752 static
 753 char const *
 754 translate_code (char *code, location loc, bool plain)
 755 {
 756   code_props plain_code;
 757   if (plain)
 758     code_props_plain_init (&plain_code, code, loc);
 759   else
 760     code_props_symbol_action_init (&plain_code, code, loc);
 761   code_props_translate_code (&plain_code);
 762   gram_scanner_last_string_free ();
 763   return plain_code.code;
 764 }
 765
 766 static
 767 char const *
 768 translate_code_braceless (char *code, location loc)
 769 {
 770   return translate_code (strip_braces (code), loc, true);
 771 }
 772
 773 static void
 774 add_param (param_type type, char *decl, location loc)
 775 {
 776   static char const alphanum[26 + 26 + 1 + 10] =
 777     "abcdefghijklmnopqrstuvwxyz"
 778     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 779     "_"
 780     "0123456789";
 781
 782   char const *name_start = NULL;
 783   {
 784     char *p;
 785     /* Stop on last actual character.  */
 786     for (p = decl; p[1]; p++)
 787       if ((p == decl
 788            || ! memchr (alphanum, p[-1], sizeof alphanum))
 789           && memchr (alphanum, p[0], sizeof alphanum - 10))
 790         name_start = p;
 791
 792     /* Strip the surrounding '{' and '}', and any blanks just inside
 793        the braces.  */
 794     --p;
 795   while (c_isspace ((unsigned char) *p))
 796       --p;
 797     p[1] = '\0';
 798     ++decl;
 799   while (c_isspace ((unsigned char) *decl))
 800       ++decl;
 801   }
 802
 803   if (! name_start)
 804     complain (&loc, complaint, _("missing identifier in parameter declaration"));
 805   else
 806     {
 807       char *name = xmemdup0 (name_start, strspn (name_start, alphanum));
 808       if (type & param_lex)
 809         muscle_pair_list_grow ("lex_param", decl, name);
 810       if (type & param_parse)
 811         muscle_pair_list_grow ("parse_param", decl, name);
 812       free (name);
 813     }
 814
 815   gram_scanner_last_string_free ();
 816 }
 817
 818
 819 static void
 820 version_check (location const *loc, char const *version)
 821 {
 822   if (strverscmp (version, PACKAGE_VERSION) > 0)
 823     {
 824       complain (loc, complaint, "require bison %s, but have %s",
 825                 version, PACKAGE_VERSION);
 826       exit (EX_MISMATCH);
 827     }
 828 }
 829
 830 static void
 831 gram_error (location const *loc, char const *msg)
 832 {
 833   complain (loc, complaint, "%s", msg);
 834 }
 835
 836 char const *
 837 token_name (int type)
 838 {
 839   return yytname[YYTRANSLATE (type)];
 840 }
 841
 842 static char const *
 843 char_name (char c)
 844 {
 845   if (c == '\'')
 846     return "'\\''";
 847   else
 848     {
 849       char buf[4];
 850       buf[0] = '\''; buf[1] = c; buf[2] = '\''; buf[3] = '\0';
 851       return quotearg_style (escape_quoting_style, buf);
 852     }
 853 }
 854
 855 static
 856 void
 857 current_lhs (symbol *sym, location loc, named_ref *ref)
 858 {
 859   current_lhs_symbol = sym;
 860   current_lhs_location = loc;
 861   /* In order to simplify memory management, named references for lhs
 862      are always assigned by deep copy into the current symbol_list
 863      node.  This is because a single named-ref in the grammar may
 864      result in several uses when the user factors lhs between several
 865      rules using "|".  Therefore free the parser's original copy.  */
 866   free (current_lhs_named_ref);
 867   current_lhs_named_ref = ref;
 868 }