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