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 /*----------.
  26 | Symbols.  |
  27 `----------*/
  28
  29 /* Associativity values for tokens and rules.  */
  30 typedef enum
  31 {
  32   right_assoc,
  33   left_assoc,
  34   non_assoc
  35 } associativity;
  36
  37
  38 /* Symbol classes.  */
  39 typedef enum
  40 {
  41   unknown_sym,
  42   token_sym,            /* terminal symbol */
  43   nterm_sym             /* non-terminal */
  44 } symbol_class;
  45
  46
  47 /* Internal token numbers. */
  48 typedef short symbol_number_t;
  49
  50
  51 typedef struct symbol_s symbol_t;
  52 struct symbol_s
  53 {
  54   /* The key, name of the symbol. */
  55   char *tag;
  56   /* Its type. */
  57   char *type_name;
  58
  59   symbol_number_t number;
  60   short prec;
  61   associativity assoc;
  62   int user_token_number;
  63
  64   /* Points to the other in the identifier-symbol pair for an alias.
  65      Special value USER_NUMBER_ALIAS in the identifier half of the
  66      identifier-symbol pair for an alias.  */
  67   symbol_t *alias;
  68   symbol_class class;
  69 };
  70
  71 /* Undefined user number.  */
  72 #define USER_NUMBER_UNDEFINED -1
  73
  74 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  75    *has* (not is) a string literal alias.  For instance, `%token foo
  76    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  77    USER_NUMBER_ALIAS.  */
  78 #define USER_NUMBER_ALIAS -9991
  79
  80 /* Undefined internal token number.  */
  81 #define NUMBER_UNDEFINED ((symbol_number_t) -1)
  82
  83
  84 /* Fetch (or create) the symbol associated to KEY.  */
  85 symbol_t *getsym PARAMS ((const char *key));
  86
  87 /* Declare the new SYMBOL.  Make it an alias of SYMVAL, and type */
  88 /* them with TYPENAME.                                           */
  89 void symbol_make_alias PARAMS ((symbol_t *symbol, symbol_t *symval,
  90                                 char *typename));
  91
  92 /* Set the TYPE_NAME associated to SYMBOL. */
  93 void symbol_type_set PARAMS ((symbol_t *symbol, char *type_name));
  94
  95 /* Set the PRECEDENCE associated to SYMBOL.  */
  96 void symbol_precedence_set PARAMS ((symbol_t *symbol,
  97                                     int prec, associativity assoc));
  98
  99 /* Set the CLASS associated to SYMBOL.  */
 100 void symbol_class_set PARAMS ((symbol_t *symbol, symbol_class class));
 101
 102 /* Set the USER_TOKEN_NUMBER associated to SYMBOL.  */
 103 void symbol_user_token_number_set PARAMS ((symbol_t *symbol, int user_number));
 104
 105
 106 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 107    by the automaton.  STARTSYMBOL is the one specified by the user.
 108    */
 109 extern symbol_t *errtoken;
 110 extern symbol_t *undeftoken;
 111 extern symbol_t *eoftoken;
 112 extern symbol_t *axiom;
 113 extern symbol_t *startsymbol;
 114
 115
 116 /*---------------.
 117 | Symbol table.  |
 118 `---------------*/
 119
 120
 121 /* Create the symbol table.  */
 122 void symbols_new PARAMS ((void));
 123
 124 /* A function to apply to each symbol. */
 125 typedef bool (*symbol_processor) PARAMS ((symbol_t *));
 126
 127 /* Apply PROCESSOR to all the symbols.  PROCESSOR must return TRUE: on
 128    FALSE, the processing stops.  */
 129 void symbols_do PARAMS ((symbol_processor processor, void *processor_data));
 130
 131 /* Free all the memory allocated for symbols.  */
 132 void symbols_free PARAMS ((void));
 133
 134 /* Check that all the symbols are defined.  Report any undefined */
 135 /* symbols and consider them nonterminals.                       */
 136 void symbols_check_defined PARAMS ((void));
 137
 138 /* Perform various sanity checks, assign symbol numbers, and set up
 139    TOKEN_TRANSLATIONS.  */
 140 void symbols_pack PARAMS ((void));
 141
 142 #endif /* !SYMTAB_H_ */