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 #include <config.h>
  21 #include "system.h"
  22
  23 #include "c-ctype.h"
  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 "named-ref.h"
  31 #include "quotearg.h"
  32 #include "reader.h"
  33 #include "symlist.h"
  34 #include "scan-gram.h"
  35 #include "scan-code.h"
  36 #include "xmemdup0.h"
  37
  38 #define YYLLOC_DEFAULT(Current, Rhs, N)  (Current) = lloc_default (Rhs, N)
  39 static YYLTYPE lloc_default (YYLTYPE const *, int);
  40
  41 #define YY_LOCATION_PRINT(File, Loc) \
  42           location_print (File, Loc)
  43
  44 static void version_check (location const *loc, char const *version);
  45
  46 /* Request detailed syntax error messages, and pass them to GRAM_ERROR.
  47    FIXME: depends on the undocumented availability of YYLLOC.  */
  48 #undef  yyerror
  49 #define yyerror(Msg) \
  50         gram_error (&yylloc, Msg)
  51 static void gram_error (location const *, char const *);
  52
  53 static char const *char_name (char);
  54
  55 /** Add a lex-param or a parse-param.
  56  *
  57  * \param type  \a lex_param or \a parse_param
  58  * \param decl  the formal argument
  59  * \param loc   the location in the source.
  60  */
  61 static void add_param (char const *type, char *decl, location loc);
  62
  63
  64 static symbol_class current_class = unknown_sym;
  65 static uniqstr current_type = NULL;
  66 static symbol *current_lhs_symbol;
  67 static location current_lhs_location;
  68 static named_ref *current_lhs_named_ref;
  69 static int current_prec = 0;
  70
  71 /** Set the new current left-hand side symbol, possibly common
  72  * to several right-hand side parts of rule.
  73  */
  74 static
  75 void
  76 current_lhs(symbol *sym, location loc, named_ref *ref)
  77 {
  78   current_lhs_symbol = sym;
  79   current_lhs_location = loc;
  80   /* In order to simplify memory management, named references for lhs
  81      are always assigned by deep copy into the current symbol_list
  82      node.  This is because a single named-ref in the grammar may
  83      result in several uses when the user factors lhs between several
  84      rules using "|".  Therefore free the parser's original copy.  */
  85   free (current_lhs_named_ref);
  86   current_lhs_named_ref = ref;
  87 }
  88
  89
  90 #define YYTYPE_INT16 int_fast16_t
  91 #define YYTYPE_INT8 int_fast8_t
  92 #define YYTYPE_UINT16 uint_fast16_t
  93 #define YYTYPE_UINT8 uint_fast8_t
  94 %}
  95
  96 %debug
  97 %define api.prefix "gram_"
  98 %define api.pure
  99 %define parse.lac full
 100 %defines
 101 %error-verbose
 102 %expect 0
 103 %locations
 104 %verbose
 105
 106 %initial-action
 107 {
 108   /* Bison's grammar can initial empty locations, hence a default
 109      location is needed. */
 110   boundary_set (&@$.start, current_file, 1, 1);
 111   boundary_set (&@$.end, current_file, 1, 1);
 112 }
 113
 114 %union
 115 {
 116   symbol *symbol;
 117   symbol_list *list;
 118   int integer;
 119   char const *chars;
 120   char *code;
 121   assoc assoc;
 122   uniqstr uniqstr;
 123   unsigned char character;
 124   named_ref *named_ref;
 125 };
 126
 127 /* Define the tokens together with their human representation.  */
 128 %token GRAM_EOF 0 "end of file"
 129 %token STRING     "string"
 130 %token INT        "integer"
 131
 132 %token PERCENT_TOKEN       "%token"
 133 %token PERCENT_NTERM       "%nterm"
 134
 135 %token PERCENT_TYPE        "%type"
 136 %token PERCENT_DESTRUCTOR  "%destructor"
 137 %token PERCENT_PRINTER     "%printer"
 138
 139 %token PERCENT_LEFT        "%left"
 140 %token PERCENT_RIGHT       "%right"
 141 %token PERCENT_NONASSOC    "%nonassoc"
 142
 143 %token PERCENT_PREC          "%prec"
 144 %token PERCENT_DPREC         "%dprec"
 145 %token PERCENT_MERGE         "%merge"
 146
 147
 148 /*----------------------.
 149 | Global Declarations.  |
 150 `----------------------*/
 151
 152 %token
 153   PERCENT_CODE            "%code"
 154   PERCENT_DEBUG           "%debug"
 155   PERCENT_DEFAULT_PREC    "%default-prec"
 156   PERCENT_DEFINE          "%define"
 157   PERCENT_DEFINES         "%defines"
 158   PERCENT_ERROR_VERBOSE   "%error-verbose"
 159   PERCENT_EXPECT          "%expect"
 160   PERCENT_EXPECT_RR       "%expect-rr"
 161   PERCENT_FILE_PREFIX     "%file-prefix"
 162   PERCENT_GLR_PARSER      "%glr-parser"
 163   PERCENT_INITIAL_ACTION  "%initial-action"
 164   PERCENT_LANGUAGE        "%language"
 165   PERCENT_LEX_PARAM       "%lex-param"
 166   PERCENT_LOCATIONS       "%locations"
 167   PERCENT_NAME_PREFIX     "%name-prefix"
 168   PERCENT_NO_DEFAULT_PREC "%no-default-prec"
 169   PERCENT_NO_LINES        "%no-lines"
 170   PERCENT_NONDETERMINISTIC_PARSER
 171                           "%nondeterministic-parser"
 172   PERCENT_OUTPUT          "%output"
 173   PERCENT_PARSE_PARAM     "%parse-param"
 174   PERCENT_PURE_PARSER     "%pure-parser"
 175   PERCENT_REQUIRE         "%require"
 176   PERCENT_SKELETON        "%skeleton"
 177   PERCENT_START           "%start"
 178   PERCENT_TOKEN_TABLE     "%token-table"
 179   PERCENT_VERBOSE         "%verbose"
 180   PERCENT_YACC            "%yacc"
 181 ;
 182
 183 %token BRACED_CODE     "{...}"
 184 %token BRACKETED_ID    "[identifier]"
 185 %token CHAR            "char"
 186 %token EPILOGUE        "epilogue"
 187 %token EQUAL           "="
 188 %token ID              "identifier"
 189 %token ID_COLON        "identifier:"
 190 %token PERCENT_PERCENT "%%"
 191 %token PIPE            "|"
 192 %token PROLOGUE        "%{...%}"
 193 %token SEMICOLON       ";"
 194 %token TYPE            "type"
 195 %token TYPE_TAG_ANY    "<*>"
 196 %token TYPE_TAG_NONE   "<>"
 197
 198 %type <character> CHAR
 199 %printer { fputs (char_name ($$), stderr); } CHAR
 200
 201 /* braceless is not to be used for rule or symbol actions, as it
 202    calls code_props_plain_init.  */
 203 %type <chars> STRING "%{...%}" EPILOGUE braceless content.opt
 204 %type <code> "{...}"
 205 %printer { fputs (quotearg_style (c_quoting_style, $$), stderr); }
 206          STRING
 207 %printer { fprintf (stderr, "{\n%s\n}", $$); }
 208          braceless content.opt "{...}" "%{...%}" EPILOGUE
 209
 210 %type <uniqstr> BRACKETED_ID ID ID_COLON TYPE variable
 211 %printer { fputs ($$, stderr); } <uniqstr>
 212 %printer { fprintf (stderr, "[%s]", $$); } BRACKETED_ID
 213 %printer { fprintf (stderr, "%s:", $$); } ID_COLON
 214 %printer { fprintf (stderr, "<%s>", $$); } TYPE
 215
 216 %type <integer> INT
 217 %printer { fprintf (stderr, "%d", $$); } <integer>
 218
 219 %type <symbol> id id_colon string_as_id symbol symbol.prec
 220 %printer { fprintf (stderr, "%s", $$->tag); } <symbol>
 221 %printer { fprintf (stderr, "%s:", $$->tag); } id_colon
 222
 223 %type <assoc> precedence_declarator
 224 %type <list>  symbols.1 symbols.prec generic_symlist generic_symlist_item
 225 %type <named_ref> named_ref.opt
 226
 227 %%
 228
 229 input:
 230   prologue_declarations "%%" grammar epilogue.opt
 231 ;
 232
 233
 234         /*------------------------------------.
 235         | Declarations: before the first %%.  |
 236         `------------------------------------*/
 237
 238 prologue_declarations:
 239   /* Nothing */
 240 | prologue_declarations prologue_declaration
 241 ;
 242
 243 prologue_declaration:
 244   grammar_declaration
 245 | "%{...%}"
 246     {
 247       code_props plain_code;
 248       code_props_plain_init (&plain_code, $1, @1);
 249       code_props_translate_code (&plain_code);
 250       gram_scanner_last_string_free ();
 251       muscle_code_grow (union_seen ? "post_prologue" : "pre_prologue",
 252                         plain_code.code, @1);
 253       code_scanner_last_string_free ();
 254     }
 255 | "%debug"                         { debug = true; }
 256 | "%define" variable content.opt
 257     {
 258       muscle_percent_define_insert ($2, @2, $3,
 259                                     MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 260     }
 261 | "%defines"                       { defines_flag = true; }
 262 | "%defines" STRING
 263     {
 264       defines_flag = true;
 265       spec_defines_file = xstrdup ($2);
 266     }
 267 | "%error-verbose"                 { error_verbose = true; }
 268 | "%expect" INT                    { expected_sr_conflicts = $2; }
 269 | "%expect-rr" INT                 { expected_rr_conflicts = $2; }
 270 | "%file-prefix" STRING            { spec_file_prefix = $2; }
 271 | "%file-prefix" "=" STRING        { spec_file_prefix = $3; } /* deprecated */
 272 | "%glr-parser"
 273     {
 274       nondeterministic_parser = true;
 275       glr_parser = true;
 276     }
 277 | "%initial-action" "{...}"
 278     {
 279       code_props action;
 280       code_props_symbol_action_init (&action, $2, @2);
 281       code_props_translate_code (&action);
 282       gram_scanner_last_string_free ();
 283       muscle_code_grow ("initial_action", action.code, @2);
 284       code_scanner_last_string_free ();
 285     }
 286 | "%language" STRING            { language_argmatch ($2, grammar_prio, @1); }
 287 | "%lex-param" "{...}"          { add_param ("lex_param", $2, @2); }
 288 | "%locations"                  { locations_flag = true; }
 289 | "%name-prefix" STRING         { spec_name_prefix = $2; }
 290 | "%name-prefix" "=" STRING     { spec_name_prefix = $3; } /* deprecated */
 291 | "%no-lines"                   { no_lines_flag = true; }
 292 | "%nondeterministic-parser"    { nondeterministic_parser = true; }
 293 | "%output" STRING              { spec_outfile = $2; }
 294 | "%output" "=" STRING          { spec_outfile = $3; }  /* deprecated */
 295 | "%parse-param" "{...}"        { add_param ("parse_param", $2, @2); }
 296 | "%pure-parser"
 297     {
 298       /* %pure-parser is deprecated in favor of `%define api.pure', so use
 299          `%define api.pure' in a backward-compatible manner here.  First, don't
 300          complain if %pure-parser is specified multiple times.  */
 301       if (!muscle_find_const ("percent_define(api.pure)"))
 302         muscle_percent_define_insert ("api.pure", @1, "",
 303                                       MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 304       /* In all cases, use api.pure now so that the backend doesn't complain if
 305          the skeleton ignores api.pure, but do warn now if there's a previous
 306          conflicting definition from an actual %define.  */
 307       if (!muscle_percent_define_flag_if ("api.pure"))
 308         muscle_percent_define_insert ("api.pure", @1, "",
 309                                       MUSCLE_PERCENT_DEFINE_GRAMMAR_FILE);
 310     }
 311 | "%require" STRING             { version_check (&@2, $2); }
 312 | "%skeleton" STRING
 313     {
 314       char const *skeleton_user = $2;
 315       if (mbschr (skeleton_user, '/'))
 316         {
 317           size_t dir_length = strlen (current_file);
 318           char *skeleton_build;
 319           while (dir_length && current_file[dir_length - 1] != '/')
 320             --dir_length;
 321           while (dir_length && current_file[dir_length - 1] == '/')
 322             --dir_length;
 323           skeleton_build =
 324             xmalloc (dir_length + 1 + strlen (skeleton_user) + 1);
 325           if (dir_length > 0)
 326             {
 327               memcpy (skeleton_build, current_file, dir_length);
 328               skeleton_build[dir_length++] = '/';
 329             }
 330           strcpy (skeleton_build + dir_length, skeleton_user);
 331           skeleton_user = uniqstr_new (skeleton_build);
 332           free (skeleton_build);
 333         }
 334       skeleton_arg (skeleton_user, grammar_prio, @1);
 335     }
 336 | "%token-table"                { token_table_flag = true; }
 337 | "%verbose"                    { report_flag |= report_states; }
 338 | "%yacc"                       { yacc_flag = true; }
 339 | /*FIXME: Err?  What is this horror doing here? */ ";"
 340 ;
 341
 342 grammar_declaration:
 343   precedence_declaration
 344 | symbol_declaration
 345 | "%start" symbol
 346     {
 347       grammar_start_symbol_set ($2, @2);
 348     }
 349 | "%destructor" "{...}" generic_symlist
 350     {
 351       code_props code;
 352       code_props_symbol_action_init (&code, $2, @2);
 353       code_props_translate_code (&code);
 354       {
 355         symbol_list *list;
 356         for (list = $3; list; list = list->next)
 357           symbol_list_destructor_set (list, &code);
 358         symbol_list_free ($3);
 359       }
 360     }
 361 | "%printer" "{...}" generic_symlist
 362     {
 363       code_props code;
 364       code_props_symbol_action_init (&code, $2, @2);
 365       code_props_translate_code (&code);
 366       {
 367         symbol_list *list;
 368         for (list = $3; list; list = list->next)
 369           symbol_list_printer_set (list, &code);
 370         symbol_list_free ($3);
 371       }
 372     }
 373 | "%default-prec"
 374     {
 375       default_prec = true;
 376     }
 377 | "%no-default-prec"
 378     {
 379       default_prec = false;
 380     }
 381 | "%code" braceless
 382     {
 383       /* Do not invoke muscle_percent_code_grow here since it invokes
 384          muscle_user_name_list_grow.  */
 385       muscle_code_grow ("percent_code()", $2, @2);
 386       code_scanner_last_string_free ();
 387     }
 388 | "%code" ID braceless
 389     {
 390       muscle_percent_code_grow ($2, @2, $3, @3);
 391       code_scanner_last_string_free ();
 392     }
 393 ;
 394
 395
 396 /*----------*
 397  | %union.  |
 398  *----------*/
 399
 400 %token PERCENT_UNION "%union";
 401
 402 union_name:
 403   /* Nothing. */ {}
 404 | ID             { muscle_code_grow ("union_name", $1, @1); }
 405 ;
 406
 407 grammar_declaration:
 408   "%union" union_name braceless
 409     {
 410       union_seen = true;
 411       muscle_code_grow ("stype", $3, @3);
 412       code_scanner_last_string_free ();
 413     }
 414 ;
 415
 416
 417
 418
 419 symbol_declaration:
 420   "%nterm" { current_class = nterm_sym; } symbol_defs.1
 421     {
 422       current_class = unknown_sym;
 423       current_type = NULL;
 424     }
 425 | "%token" { current_class = token_sym; } symbol_defs.1
 426     {
 427       current_class = unknown_sym;
 428       current_type = NULL;
 429     }
 430 | "%type" TYPE symbols.1
 431     {
 432       symbol_list *list;
 433       tag_seen = true;
 434       for (list = $3; list; list = list->next)
 435         symbol_type_set (list->content.sym, $2, @2);
 436       symbol_list_free ($3);
 437     }
 438 ;
 439
 440 precedence_declaration:
 441   precedence_declarator type.opt symbols.prec
 442     {
 443       symbol_list *list;
 444       ++current_prec;
 445       for (list = $3; list; list = list->next)
 446         {
 447           symbol_type_set (list->content.sym, current_type, @2);
 448           symbol_precedence_set (list->content.sym, current_prec, $1, @1);
 449         }
 450       symbol_list_free ($3);
 451       current_type = NULL;
 452     }
 453 ;
 454
 455 precedence_declarator:
 456   "%left"     { $$ = left_assoc; }
 457 | "%right"    { $$ = right_assoc; }
 458 | "%nonassoc" { $$ = non_assoc; }
 459 ;
 460
 461 type.opt:
 462   /* Nothing. */ { current_type = NULL; }
 463 | TYPE           { current_type = $1; tag_seen = true; }
 464 ;
 465
 466 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
 467 symbols.prec:
 468   symbol.prec
 469     { $$ = symbol_list_sym_new ($1, @1); }
 470 | symbols.prec symbol.prec
 471     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 472 ;
 473
 474 symbol.prec:
 475     symbol { $$ = $1; }
 476   | symbol INT { $$ = $1; symbol_user_token_number_set ($1, $2, @2); }
 477   ;
 478
 479 /* One or more symbols to be %typed. */
 480 symbols.1:
 481   symbol
 482     { $$ = symbol_list_sym_new ($1, @1); }
 483 | symbols.1 symbol
 484     { $$ = symbol_list_prepend ($1, symbol_list_sym_new ($2, @2)); }
 485 ;
 486
 487 generic_symlist:
 488   generic_symlist_item { $$ = $1; }
 489 | generic_symlist generic_symlist_item { $$ = symbol_list_prepend ($1, $2); }
 490 ;
 491
 492 generic_symlist_item:
 493   symbol            { $$ = symbol_list_sym_new ($1, @1); }
 494 | TYPE              { $$ = symbol_list_type_new ($1, @1); }
 495 | "<*>"             { $$ = symbol_list_default_tagged_new (@1); }
 496 | "<>"             { $$ = symbol_list_default_tagless_new (@1); }
 497 ;
 498
 499 /* One token definition.  */
 500 symbol_def:
 501   TYPE
 502      {
 503        current_type = $1;
 504        tag_seen = true;
 505      }
 506 | id
 507      {
 508        symbol_class_set ($1, current_class, @1, true);
 509        symbol_type_set ($1, current_type, @1);
 510      }
 511 | id INT
 512     {
 513       symbol_class_set ($1, current_class, @1, true);
 514       symbol_type_set ($1, current_type, @1);
 515       symbol_user_token_number_set ($1, $2, @2);
 516     }
 517 | id string_as_id
 518     {
 519       symbol_class_set ($1, current_class, @1, true);
 520       symbol_type_set ($1, current_type, @1);
 521       symbol_make_alias ($1, $2, @$);
 522     }
 523 | id INT string_as_id
 524     {
 525       symbol_class_set ($1, current_class, @1, true);
 526       symbol_type_set ($1, current_type, @1);
 527       symbol_user_token_number_set ($1, $2, @2);
 528       symbol_make_alias ($1, $3, @$);
 529     }
 530 ;
 531
 532 /* One or more symbol definitions. */
 533 symbol_defs.1:
 534   symbol_def
 535 | symbol_defs.1 symbol_def
 536 ;
 537
 538
 539         /*------------------------------------------.
 540         | The grammar section: between the two %%.  |
 541         `------------------------------------------*/
 542
 543 grammar:
 544   rules_or_grammar_declaration
 545 | grammar rules_or_grammar_declaration
 546 ;
 547
 548 /* As a Bison extension, one can use the grammar declarations in the
 549    body of the grammar.  */
 550 rules_or_grammar_declaration:
 551   rules
 552 | grammar_declaration ";"
 553 | error ";"
 554     {
 555       yyerrok;
 556     }
 557 ;
 558
 559 rules:
 560   id_colon named_ref.opt { current_lhs ($1, @1, $2); } rhses.1
 561   {
 562     /* Free the current lhs. */
 563     current_lhs (0, @1, 0);
 564   }
 565 ;
 566
 567 rhses.1:
 568   rhs                { grammar_current_rule_end (@1); }
 569 | rhses.1 "|" rhs    { grammar_current_rule_end (@3); }
 570 | rhses.1 ";"
 571 ;
 572
 573 rhs:
 574   /* Nothing.  */
 575     { grammar_current_rule_begin (current_lhs_symbol, current_lhs_location,
 576                                   current_lhs_named_ref); }
 577 | rhs symbol named_ref.opt
 578     { grammar_current_rule_symbol_append ($2, @2, $3); }
 579 | rhs "{...}" named_ref.opt
 580     { grammar_current_rule_action_append ($2, @2, $3); }
 581 | rhs "%prec" symbol
 582     { grammar_current_rule_prec_set ($3, @3); }
 583 | rhs "%dprec" INT
 584     { grammar_current_rule_dprec_set ($3, @3); }
 585 | rhs "%merge" TYPE
 586     { grammar_current_rule_merge_set ($3, @3); }
 587 ;
 588
 589 named_ref.opt:
 590   /* Nothing. */ { $$ = 0; }
 591 |
 592   BRACKETED_ID   { $$ = named_ref_new($1, @1); }
 593 ;
 594
 595
 596 /*----------------------------*
 597  | variable and content.opt.  |
 598  *---------------------------*/
 599
 600 /* The STRING form of variable is deprecated and is not M4-friendly.
 601    For example, M4 fails for `%define "[" "value"'.  */
 602 variable:
 603   ID
 604 | STRING { $$ = uniqstr_new ($1); }
 605 ;
 606
 607 /* Some content or empty by default. */
 608 content.opt:
 609   /* Nothing. */   { $$ = ""; }
 610 | ID { $$ = $1; }
 611 | STRING
 612 ;
 613
 614
 615 /*-------------*
 616  | braceless.  |
 617  *-------------*/
 618
 619 braceless:
 620   "{...}"
 621     {
 622       code_props plain_code;
 623       $1[strlen ($1) - 1] = '\n';
 624       code_props_plain_init (&plain_code, $1+1, @1);
 625       code_props_translate_code (&plain_code);
 626       gram_scanner_last_string_free ();
 627       $$ = plain_code.code;
 628     }
 629 ;
 630
 631
 632 /*---------------*
 633  | Identifiers.  |
 634  *---------------*/
 635
 636 /* Identifiers are returned as uniqstr values by the scanner.
 637    Depending on their use, we may need to make them genuine symbols.  */
 638
 639 id:
 640   ID
 641     { $$ = symbol_from_uniqstr ($1, @1); }
 642 | CHAR
 643     {
 644       $$ = symbol_get (char_name ($1), @1);
 645       symbol_class_set ($$, token_sym, @1, false);
 646       symbol_user_token_number_set ($$, $1, @1);
 647     }
 648 ;
 649
 650 id_colon:
 651   ID_COLON { $$ = symbol_from_uniqstr ($1, @1); }
 652 ;
 653
 654
 655 symbol:
 656   id
 657 | string_as_id
 658 ;
 659
 660 /* A string used as an ID: quote it.  */
 661 string_as_id:
 662   STRING
 663     {
 664       $$ = symbol_get (quotearg_style (c_quoting_style, $1), @1);
 665       symbol_class_set ($$, token_sym, @1, false);
 666     }
 667 ;
 668
 669 epilogue.opt:
 670   /* Nothing.  */
 671 | "%%" EPILOGUE
 672     {
 673       code_props plain_code;
 674       code_props_plain_init (&plain_code, $2, @2);
 675       code_props_translate_code (&plain_code);
 676       gram_scanner_last_string_free ();
 677       muscle_code_grow ("epilogue", plain_code.code, @2);
 678       code_scanner_last_string_free ();
 679     }
 680 ;
 681
 682 %%
 683
 684
 685 /* Return the location of the left-hand side of a rule whose
 686    right-hand side is RHS[1] ... RHS[N].  Ignore empty nonterminals in
 687    the right-hand side, and return an empty location equal to the end
 688    boundary of RHS[0] if the right-hand side is empty.  */
 689
 690 static YYLTYPE
 691 lloc_default (YYLTYPE const *rhs, int n)
 692 {
 693   int i;
 694   YYLTYPE loc;
 695
 696   /* SGI MIPSpro 7.4.1m miscompiles "loc.start = loc.end = rhs[n].end;".
 697      The bug is fixed in 7.4.2m, but play it safe for now.  */
 698   loc.start = rhs[n].end;
 699   loc.end = rhs[n].end;
 700
 701   /* Ignore empty nonterminals the start of the right-hand side.
 702      Do not bother to ignore them at the end of the right-hand side,
 703      since empty nonterminals have the same end as their predecessors.  */
 704   for (i = 1; i <= n; i++)
 705     if (! equal_boundaries (rhs[i].start, rhs[i].end))
 706       {
 707         loc.start = rhs[i].start;
 708         break;
 709       }
 710
 711   return loc;
 712 }
 713
 714
 715 /* Add a lex-param or a parse-param (depending on TYPE) with
 716    declaration DECL and location LOC.  */
 717
 718 static void
 719 add_param (char const *type, char *decl, location loc)
 720 {
 721   static char const alphanum[26 + 26 + 1 + 10] =
 722     "abcdefghijklmnopqrstuvwxyz"
 723     "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 724     "_"
 725     "0123456789";
 726   char const *name_start = NULL;
 727   char *p;
 728
 729   /* Stop on last actual character.  */
 730   for (p = decl; p[1]; p++)
 731     if ((p == decl
 732          || ! memchr (alphanum, p[-1], sizeof alphanum))
 733         && memchr (alphanum, p[0], sizeof alphanum - 10))
 734       name_start = p;
 735
 736   /* Strip the surrounding '{' and '}', and any blanks just inside
 737      the braces.  */
 738   --p;
 739   while (c_isspace ((unsigned char) *p))
 740     --p;
 741   p[1] = '\0';
 742   ++decl;
 743   while (c_isspace ((unsigned char) *decl))
 744     ++decl;
 745
 746   if (! name_start)
 747     complain_at (loc, _("missing identifier in parameter declaration"));
 748   else
 749     {
 750       char *name = xmemdup0 (name_start, strspn (name_start, alphanum));
 751       muscle_pair_list_grow (type, decl, name);
 752       free (name);
 753     }
 754
 755   gram_scanner_last_string_free ();
 756 }
 757
 758
 759 static void
 760 version_check (location const *loc, char const *version)
 761 {
 762   if (strverscmp (version, PACKAGE_VERSION) > 0)
 763     {
 764       complain_at (*loc, "require bison %s, but have %s",
 765                    version, PACKAGE_VERSION);
 766       exit (EX_MISMATCH);
 767     }
 768 }
 769
 770 static void
 771 gram_error (location const *loc, char const *msg)
 772 {
 773   complain_at (*loc, "%s", msg);
 774 }
 775
 776 char const *
 777 token_name (int type)
 778 {
 779   return yytname[YYTRANSLATE (type)];
 780 }
 781
 782 static char const *
 783 char_name (char c)
 784 {
 785   if (c == '\'')
 786     return "'\\''";
 787   else
 788     {
 789       char buf[4];
 790       buf[0] = '\''; buf[1] = c; buf[2] = '\''; buf[3] = '\0';
 791       return quotearg_style (escape_quoting_style, buf);
 792     }
 793 }