src/symtab.h

   1 /* Definitions for symtab.c and callers, part of Bison.
   2
   3    Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004
   4    Free Software Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    Bison is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    Bison is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with Bison; see the file COPYING.  If not, write to
  20    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #ifndef SYMTAB_H_
  24 # define SYMTAB_H_
  25
  26 # include "assoc.h"
  27 # include "location.h"
  28 # include "uniqstr.h"
  29
  30 /*----------.
  31 | Symbols.  |
  32 `----------*/
  33
  34 /* Symbol classes.  */
  35 typedef enum
  36 {
  37   unknown_sym,
  38   token_sym,            /* terminal symbol */
  39   nterm_sym             /* non-terminal */
  40 } symbol_class;
  41
  42
  43 /* Internal token numbers. */
  44 typedef short int symbol_number;
  45 #define SYMBOL_NUMBER_MAXIMUM SHRT_MAX
  46
  47
  48 typedef struct symbol symbol;
  49
  50 /* When extending this structure, be sure to complete
  51    symbol_check_alias_consistency.  */
  52 struct symbol
  53 {
  54   /* The key, name of the symbol.  */
  55   uniqstr tag;
  56   /* The location of its first occurrence.  */
  57   location location;
  58
  59   /* Its %type and associated printer and destructor.  */
  60   uniqstr type_name;
  61   location type_location;
  62
  63   char *destructor;
  64   location destructor_location;
  65
  66   char *printer;
  67   location printer_location;
  68
  69   symbol_number number;
  70   location prec_location;
  71   short int prec;
  72   assoc assoc;
  73   int user_token_number;
  74
  75   /* Points to the other in the identifier-symbol pair for an alias.
  76      Special value USER_NUMBER_ALIAS in the identifier half of the
  77      identifier-symbol pair for an alias.  */
  78   symbol *alias;
  79   symbol_class class;
  80 };
  81
  82 /* Undefined user number.  */
  83 #define USER_NUMBER_UNDEFINED -1
  84
  85 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  86    *has* (not is) a string literal alias.  For instance, `%token foo
  87    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  88    USER_NUMBER_ALIAS.  */
  89 #define USER_NUMBER_ALIAS -9991
  90
  91 /* Undefined internal token number.  */
  92 #define NUMBER_UNDEFINED (-1)
  93
  94
  95 /* Fetch (or create) the symbol associated to KEY.  */
  96 symbol *symbol_get (const char *key, location loc);
  97
  98 /* Generate a dummy nonterminal, whose name cannot conflict with the
  99    user's names.  */
 100 symbol *dummy_symbol_get (location loc);
 101
 102 /* Declare the new symbol SYM.  Make it an alias of SYMVAL.  */
 103 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 104
 105 /* Set the TYPE_NAME associated with SYM.  Do nothing if passed 0 as
 106    TYPE_NAME.  */
 107 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 108
 109 /* Set the DESTRUCTOR associated with SYM.  */
 110 void symbol_destructor_set (symbol *sym, char *destructor, location loc);
 111
 112 /* Set the PRINTER associated with SYM.  */
 113 void symbol_printer_set (symbol *sym, char *printer, location loc);
 114
 115 /* Set the PRECEDENCE associated with SYM.  Ensure that SYMBOL is a
 116    terminal.  Do nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 117 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 118
 119 /* Set the CLASS associated with SYM.  */
 120 void symbol_class_set (symbol *sym, symbol_class class, location loc);
 121
 122 /* Set the USER_TOKEN_NUMBER associated with SYM.  */
 123 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 124
 125
 126 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 127    by the automaton.  STARTSYMBOL is the one specified by the user.
 128    */
 129 extern symbol *errtoken;
 130 extern symbol *undeftoken;
 131 extern symbol *endtoken;
 132 extern symbol *accept;
 133 extern symbol *startsymbol;
 134 extern location startsymbol_location;
 135
 136
 137 /*---------------.
 138 | Symbol table.  |
 139 `---------------*/
 140
 141
 142 /* Create the symbol table.  */
 143 void symbols_new (void);
 144
 145 /* Free all the memory allocated for symbols.  */
 146 void symbols_free (void);
 147
 148 /* Check that all the symbols are defined.  Report any undefined
 149    symbols and consider them nonterminals.  */
 150 void symbols_check_defined (void);
 151
 152 /* Perform various sanity checks, assign symbol numbers, and set up
 153    TOKEN_TRANSLATIONS.  */
 154 void symbols_pack (void);
 155
 156 #endif /* !SYMTAB_H_ */