src/symtab.h

   1 /* Definitions for symtab.c and callers, part of bison,
   2    Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002
   3    Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    Bison 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 2, or (at your option)
  10    any later version.
  11
  12    Bison 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 Bison; see the file COPYING.  If not, write to
  19    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #ifndef SYMTAB_H_
  23 # define SYMTAB_H_
  24
  25 # include "location.h"
  26 # include "assoc.h"
  27
  28 /*----------.
  29 | Symbols.  |
  30 `----------*/
  31
  32 /* Symbol classes.  */
  33 typedef enum
  34 {
  35   unknown_sym,
  36   token_sym,            /* terminal symbol */
  37   nterm_sym             /* non-terminal */
  38 } symbol_class;
  39
  40
  41 /* Internal token numbers. */
  42 typedef short symbol_number_t;
  43
  44
  45 typedef struct symbol_s symbol_t;
  46 struct symbol_s
  47 {
  48   /* The key, name of the symbol.  */
  49   char *tag;
  50   /* The location of its first occurence.  */
  51   location_t location;
  52
  53   /* Its %type and associated printer and destructor.  */
  54   char *type_name;
  55   char *destructor;
  56   location_t destructor_location;
  57   char *printer;
  58   location_t printer_location;
  59
  60   symbol_number_t number;
  61   short prec;
  62   assoc_t assoc;
  63   int user_token_number;
  64
  65   /* Points to the other in the identifier-symbol pair for an alias.
  66      Special value USER_NUMBER_ALIAS in the identifier half of the
  67      identifier-symbol pair for an alias.  */
  68   symbol_t *alias;
  69   symbol_class class;
  70 };
  71
  72 /* Undefined user number.  */
  73 #define USER_NUMBER_UNDEFINED -1
  74
  75 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  76    *has* (not is) a string literal alias.  For instance, `%token foo
  77    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  78    USER_NUMBER_ALIAS.  */
  79 #define USER_NUMBER_ALIAS -9991
  80
  81 /* Undefined internal token number.  */
  82 #define NUMBER_UNDEFINED ((symbol_number_t) -1)
  83
  84
  85 /* Fetch (or create) the symbol associated to KEY.  */
  86 symbol_t *symbol_get PARAMS ((const char *key, location_t location));
  87
  88 /* Generate a dummy nonterminal, whose name cannot conflict with the
  89    user's names.  */
  90 symbol_t *dummy_symbol_get PARAMS ((location_t location));
  91
  92 /* Declare the new SYMBOL.  Make it an alias of SYMVAL.  */
  93 void symbol_make_alias PARAMS ((symbol_t *symbol, symbol_t *symval,
  94                                 location_t location));
  95
  96 /* Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 as
  97    TYPE_NAME.  */
  98 void symbol_type_set PARAMS ((symbol_t *symbol,
  99                               char *type_name, location_t location));
 100
 101 /* Set the DESTRUCTOR associated to SYMBOL.  */
 102 void symbol_destructor_set PARAMS ((symbol_t *symbol,
 103                                     char *destructor, location_t location));
 104
 105 /* Set the PRINTER associated to SYMBOL.  */
 106 void symbol_printer_set PARAMS ((symbol_t *symbol,
 107                                  char *printer, location_t location));
 108
 109 /* Set the PRECEDENCE associated to SYMBOL.  Ensures that SYMBOL is a
 110    terminal.  Does nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 111 void symbol_precedence_set PARAMS ((symbol_t *symbol,
 112                                     int prec, assoc_t assoc,
 113                                     location_t location));
 114
 115 /* Set the CLASS associated to SYMBOL.  */
 116 void symbol_class_set PARAMS ((symbol_t *symbol,
 117                                symbol_class class, location_t location));
 118
 119 /* Set the USER_TOKEN_NUMBER associated to SYMBOL.  */
 120 void symbol_user_token_number_set PARAMS ((symbol_t *symbol,
 121                                            int user_number,
 122                                            location_t location));
 123
 124
 125 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 126    by the automaton.  STARTSYMBOL is the one specified by the user.
 127    */
 128 extern symbol_t *errtoken;
 129 extern symbol_t *undeftoken;
 130 extern symbol_t *endtoken;
 131 extern symbol_t *accept;
 132 extern symbol_t *startsymbol;
 133 extern location_t startsymbol_location;
 134
 135
 136 /*---------------.
 137 | Symbol table.  |
 138 `---------------*/
 139
 140
 141 /* Create the symbol table.  */
 142 void symbols_new PARAMS ((void));
 143
 144 /* A function to apply to each symbol. */
 145 typedef bool (*symbol_processor) PARAMS ((symbol_t *));
 146
 147 /* Apply PROCESSOR to all the symbols.  PROCESSOR must return TRUE: on
 148    FALSE, the processing stops.  */
 149 void symbols_do PARAMS ((symbol_processor processor, void *processor_data));
 150
 151 /* Free all the memory allocated for symbols.  */
 152 void symbols_free PARAMS ((void));
 153
 154 /* Check that all the symbols are defined.  Report any undefined
 155    symbols and consider them nonterminals.  */
 156 void symbols_check_defined PARAMS ((void));
 157
 158 /* Perform various sanity checks, assign symbol numbers, and set up
 159    TOKEN_TRANSLATIONS.  */
 160 void symbols_pack PARAMS ((void));
 161
 162 #endif /* !SYMTAB_H_ */