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 #define SYMBOL_NUMBER_MAX ((symbol_number_t) SHRT_MAX)
  44
  45
  46 typedef struct symbol_s symbol_t;
  47 struct symbol_s
  48 {
  49   /* The key, name of the symbol.  */
  50   char *tag;
  51   /* The location of its first occurence.  */
  52   location_t location;
  53
  54   /* Its %type and associated printer and destructor.  */
  55   char *type_name;
  56   char *destructor;
  57   location_t destructor_location;
  58   char *printer;
  59   location_t printer_location;
  60
  61   symbol_number_t number;
  62   short prec;
  63   assoc_t assoc;
  64   int user_token_number;
  65
  66   /* Points to the other in the identifier-symbol pair for an alias.
  67      Special value USER_NUMBER_ALIAS in the identifier half of the
  68      identifier-symbol pair for an alias.  */
  69   symbol_t *alias;
  70   symbol_class class;
  71 };
  72
  73 /* Undefined user number.  */
  74 #define USER_NUMBER_UNDEFINED -1
  75
  76 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  77    *has* (not is) a string literal alias.  For instance, `%token foo
  78    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  79    USER_NUMBER_ALIAS.  */
  80 #define USER_NUMBER_ALIAS -9991
  81
  82 /* Undefined internal token number.  */
  83 #define NUMBER_UNDEFINED ((symbol_number_t) -1)
  84
  85
  86 /* Fetch (or create) the symbol associated to KEY.  */
  87 symbol_t *symbol_get (const char *key, location_t location);
  88
  89 /* Generate a dummy nonterminal, whose name cannot conflict with the
  90    user's names.  */
  91 symbol_t *dummy_symbol_get (location_t location);
  92
  93 /* Declare the new SYMBOL.  Make it an alias of SYMVAL.  */
  94 void symbol_make_alias (symbol_t *symbol, symbol_t *symval,
  95                         location_t location);
  96
  97 /* Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 as
  98    TYPE_NAME.  */
  99 void symbol_type_set (symbol_t *symbol,
 100                       char *type_name, location_t location);
 101
 102 /* Set the DESTRUCTOR associated to SYMBOL.  */
 103 void symbol_destructor_set (symbol_t *symbol,
 104                             char *destructor, location_t location);
 105
 106 /* Set the PRINTER associated to SYMBOL.  */
 107 void symbol_printer_set (symbol_t *symbol,
 108                          char *printer, location_t location);
 109
 110 /* Set the PRECEDENCE associated to SYMBOL.  Ensures that SYMBOL is a
 111    terminal.  Does nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 112 void symbol_precedence_set (symbol_t *symbol,
 113                             int prec, assoc_t assoc, location_t location);
 114
 115 /* Set the CLASS associated to SYMBOL.  */
 116 void symbol_class_set (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 (symbol_t *symbol,
 121                                    int user_number, location_t location);
 122
 123
 124 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 125    by the automaton.  STARTSYMBOL is the one specified by the user.
 126    */
 127 extern symbol_t *errtoken;
 128 extern symbol_t *undeftoken;
 129 extern symbol_t *endtoken;
 130 extern symbol_t *accept;
 131 extern symbol_t *startsymbol;
 132 extern location_t startsymbol_location;
 133
 134
 135 /*---------------.
 136 | Symbol table.  |
 137 `---------------*/
 138
 139
 140 /* Create the symbol table.  */
 141 void symbols_new (void);
 142
 143 /* A function to apply to each symbol. */
 144 typedef bool (*symbol_processor) (symbol_t *);
 145
 146 /* Apply PROCESSOR to all the symbols.  PROCESSOR must return true: on
 147    false, the processing stops.  */
 148 void symbols_do (symbol_processor processor, void *processor_data);
 149
 150 /* Free all the memory allocated for symbols.  */
 151 void symbols_free (void);
 152
 153 /* Check that all the symbols are defined.  Report any undefined
 154    symbols and consider them nonterminals.  */
 155 void symbols_check_defined (void);
 156
 157 /* Perform various sanity checks, assign symbol numbers, and set up
 158    TOKEN_TRANSLATIONS.  */
 159 void symbols_pack (void);
 160
 161 #endif /* !SYMTAB_H_ */