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      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 "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 }
    794