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 %type and associated printer and destructor.  */
  65   uniqstr type_name;
  66   location type_location;
  67
  68   /** Does not own the memory. */
  69   const char *destructor;
  70   location destructor_location;
  71
  72   /** Printer. */
  73   const char *printer;
  74   location printer_location;
  75
  76   symbol_number number;
  77   location prec_location;
  78   int prec;
  79   assoc assoc;
  80   int user_token_number;
  81
  82   /* Points to the other in the identifier-symbol pair for an alias.
  83      Special value USER_NUMBER_ALIAS in the identifier half of the
  84      identifier-symbol pair for an alias.  */
  85   symbol *alias;
  86   symbol_class class;
  87   bool declared;
  88 };
  89
  90
  91 /** Undefined user number.  */
  92 #define USER_NUMBER_UNDEFINED -1
  93
  94 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  95    *has* (not is) a string literal alias.  For instance, `%token foo
  96    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  97    USER_NUMBER_ALIAS.  */
  98 #define USER_NUMBER_ALIAS -9991
  99
 100 /* Undefined internal token number.  */
 101 #define NUMBER_UNDEFINED (-1)
 102
 103 /** Print a symbol (for debugging). */
 104 void symbol_print (symbol *s, FILE *f);
 105
 106 /** Fetch (or create) the symbol associated to KEY.  */
 107 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 108
 109 /** Fetch (or create) the symbol associated to KEY.  */
 110 symbol *symbol_get (const char *key, location loc);
 111
 112 /** Generate a dummy nonterminal.
 113
 114    Its name cannot conflict with the user's names.  */
 115 symbol *dummy_symbol_get (location loc);
 116
 117 /** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
 118 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 119
 120 /** Set the \c type_name associated with \c sym.
 121
 122     Do nothing if passed 0 as \c type_name.  */
 123 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 124
 125 /** Set the \c destructor associated with \c sym.  */
 126 void symbol_destructor_set (symbol *sym, const char *destructor, location loc);
 127
 128 /** Set the \c printer associated with \c sym.  */
 129 void symbol_printer_set (symbol *sym, const char *printer, location loc);
 130
 131 /* Set the \c precedence associated with \c sym.
 132
 133    Ensure that \a symbol is a terminal.
 134    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 135 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 136
 137 /** Set the \c class associated with \c sym.  */
 138 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 139                        bool declaring);
 140
 141 /** Set the \c user_token_number associated with \c sym.  */
 142 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 143
 144
 145 /** The error token. */
 146 extern symbol *errtoken;
 147 /** The token for unknown tokens.  */
 148 extern symbol *undeftoken;
 149 /** The end of input token.  */
 150 extern symbol *endtoken;
 151 /** The genuine start symbol.
 152
 153    $accept: start-symbol $end */
 154 extern symbol *accept;
 155
 156 /** The user start symbol. */
 157 extern symbol *startsymbol;
 158 /** The location of the \c %start declaration.  */
 159 extern location startsymbol_location;
 160
 161
 162 /*---------------.
 163 | Symbol table.  |
 164 `---------------*/
 165
 166
 167 /** Create the symbol table.  */
 168 void symbols_new (void);
 169
 170 /** Free all the memory allocated for symbols.  */
 171 void symbols_free (void);
 172
 173 /** Check that all the symbols are defined.
 174
 175     Report any undefined symbols and consider them nonterminals.  */
 176 void symbols_check_defined (void);
 177
 178 /** Sanity checks and #token_translations construction.
 179
 180    Perform various sanity checks, assign symbol numbers, and set up
 181    #token_translations.  */
 182 void symbols_pack (void);
 183
 184 #endif /* !SYMTAB_H_ */