src/symtab.h

   1 /* Definitions for symtab.c and callers, part of Bison.
   2
   3    Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004, 2005, 2006
   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., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 /**
  24  * \file symtab.h
  25  * \brief Manipulating ::symbol.
  26  */
  27
  28 #ifndef SYMTAB_H_
  29 # define SYMTAB_H_
  30
  31 # include "assoc.h"
  32 # include "location.h"
  33 # include "uniqstr.h"
  34
  35 /*----------.
  36 | Symbols.  |
  37 `----------*/
  38
  39 /** Symbol classes.  */
  40 typedef enum
  41 {
  42   unknown_sym,          /**< Undefined.  */
  43   token_sym,            /**< Terminal. */
  44   nterm_sym             /**< Non-terminal. */
  45 } symbol_class;
  46
  47
  48 /** Internal token numbers. */
  49 typedef int symbol_number;
  50 #define SYMBOL_NUMBER_MAXIMUM INT_MAX
  51
  52
  53 typedef struct symbol symbol;
  54
  55 /* When extending this structure, be sure to complete
  56    symbol_check_alias_consistency.  */
  57 struct symbol
  58 {
  59   /** The key, name of the symbol.  */
  60   uniqstr tag;
  61   /** The location of its first occurrence.  */
  62   location location;
  63
  64   /** Its \c \%type.  */
  65   uniqstr type_name;
  66   /** Its \c \%type's location.  */
  67   location type_location;
  68
  69   /** Any \c \%destructor declared specifically for this symbol.
  70
  71      Access this field only through <tt>symbol</tt>'s interface functions.  For
  72      example, if <tt>symbol::destructor = NULL</tt>, the default
  73      \c \%destructor or a per-type \c \%destructor might be appropriate, and
  74      \c symbol_destructor_get will compute the correct one.  */
  75   const char *destructor;
  76
  77   /** The location of \c symbol::destructor.
  78
  79      Access this field only through <tt>symbol</tt>'s interface functions.
  80      \sa symbol::destructor  */
  81   location destructor_location;
  82
  83   /** Any \c \%printer declared specifically for this symbol.
  84
  85      Access this field only through <tt>symbol</tt>'s interface functions.
  86      \sa symbol::destructor  */
  87   const char *printer;
  88
  89   /** The location of \c symbol::printer.
  90
  91      Access this field only through <tt>symbol</tt>'s interface functions.
  92      \sa symbol::destructor  */
  93   location printer_location;
  94
  95   symbol_number number;
  96   location prec_location;
  97   int prec;
  98   assoc assoc;
  99   int user_token_number;
 100
 101   /* Points to the other in the identifier-symbol pair for an alias.
 102      Special value USER_NUMBER_ALIAS in the identifier half of the
 103      identifier-symbol pair for an alias.  */
 104   symbol *alias;
 105   symbol_class class;
 106   bool declared;
 107 };
 108
 109
 110 /** Undefined user number.  */
 111 #define USER_NUMBER_UNDEFINED -1
 112
 113 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
 114    *has* (not is) a string literal alias.  For instance, `%token foo
 115    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
 116    USER_NUMBER_ALIAS.  */
 117 #define USER_NUMBER_ALIAS -9991
 118
 119 /* Undefined internal token number.  */
 120 #define NUMBER_UNDEFINED (-1)
 121
 122 /** Print a symbol (for debugging). */
 123 void symbol_print (symbol *s, FILE *f);
 124
 125 /** Fetch (or create) the symbol associated to KEY.  */
 126 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 127
 128 /** Fetch (or create) the symbol associated to KEY.  */
 129 symbol *symbol_get (const char *key, location loc);
 130
 131 /** Generate a dummy nonterminal.
 132
 133    Its name cannot conflict with the user's names.  */
 134 symbol *dummy_symbol_get (location loc);
 135
 136 /** Is this a dummy nonterminal?  */
 137 bool symbol_is_dummy (const symbol *sym);
 138
 139 /** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
 140 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 141
 142 /** Set the \c type_name associated with \c sym.
 143
 144     Do nothing if passed 0 as \c type_name.  */
 145 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 146
 147 /** Set the \c destructor associated with \c sym.  */
 148 void symbol_destructor_set (symbol *sym, const char *destructor, location loc);
 149
 150 /** Get the computed \c \%destructor for \c sym, or \c NULL if none.   */
 151 const char *symbol_destructor_get (symbol *sym);
 152
 153 /** Get the grammar location of the computed \c \%destructor for \c sym.
 154
 155   \pre <tt>symbol_destructor_get (sym) != NULL</tt> */
 156 location symbol_destructor_location_get (symbol *sym);
 157
 158 /** Set the \c printer associated with \c sym.  */
 159 void symbol_printer_set (symbol *sym, const char *printer, location loc);
 160
 161 /** Get the computed \c \%printer for \c sym, or \c NULL if none.  */
 162 const char *symbol_printer_get (symbol *sym);
 163
 164 /** Get the grammar location of the computed \c \%printer for \c sym.
 165
 166   \pre <tt>symbol_printer_get (sym) != NULL</tt> */
 167 location symbol_printer_location_get (symbol *sym);
 168
 169 /* Set the \c precedence associated with \c sym.
 170
 171    Ensure that \a symbol is a terminal.
 172    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 173 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 174
 175 /** Set the \c class associated with \c sym.  */
 176 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 177                        bool declaring);
 178
 179 /** Set the \c user_token_number associated with \c sym.  */
 180 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 181
 182
 183 /** The error token. */
 184 extern symbol *errtoken;
 185 /** The token for unknown tokens.  */
 186 extern symbol *undeftoken;
 187 /** The end of input token.  */
 188 extern symbol *endtoken;
 189 /** The genuine start symbol.
 190
 191    $accept: start-symbol $end */
 192 extern symbol *accept;
 193
 194 /** The user start symbol. */
 195 extern symbol *startsymbol;
 196 /** The location of the \c \%start declaration.  */
 197 extern location startsymbol_location;
 198
 199
 200 /*---------------.
 201 | Symbol table.  |
 202 `---------------*/
 203
 204
 205 /** Create the symbol table.  */
 206 void symbols_new (void);
 207
 208 /** Free all the memory allocated for symbols.  */
 209 void symbols_free (void);
 210
 211 /** Check that all the symbols are defined.
 212
 213     Report any undefined symbols and consider them nonterminals.  */
 214 void symbols_check_defined (void);
 215
 216 /** Sanity checks and #token_translations construction.
 217
 218    Perform various sanity checks, assign symbol numbers, and set up
 219    #token_translations.  */
 220 void symbols_pack (void);
 221
 222
 223 /*-----------------------------------.
 224 | Default %destructor and %printer.  |
 225 `-----------------------------------*/
 226
 227 /** Set the default \c \%destructor.  */
 228 void default_destructor_set (const char *destructor, location loc);
 229
 230 /** Set the default \c \%printer.  */
 231 void default_printer_set (const char *printer, location loc);
 232
 233 #endif /* !SYMTAB_H_ */