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
  27 /*----------.
  28 | Symbols.  |
  29 `----------*/
  30
  31 /* Associativity values for tokens and rules.  */
  32 typedef enum
  33 {
  34   undef_assoc,
  35   right_assoc,
  36   left_assoc,
  37   non_assoc
  38 } associativity;
  39
  40
  41 /* Symbol classes.  */
  42 typedef enum
  43 {
  44   unknown_sym,
  45   token_sym,            /* terminal symbol */
  46   nterm_sym             /* non-terminal */
  47 } symbol_class;
  48
  49
  50 /* Internal token numbers. */
  51 typedef short symbol_number_t;
  52
  53
  54 typedef struct symbol_s symbol_t;
  55 struct symbol_s
  56 {
  57   /* The key, name of the symbol. */
  58   char *tag;
  59   /* Its type. */
  60   char *type_name;
  61
  62   /* The location of its first occurence. */
  63   location_t location;
  64
  65   symbol_number_t number;
  66   short prec;
  67   associativity assoc;
  68   int user_token_number;
  69
  70   /* Points to the other in the identifier-symbol pair for an alias.
  71      Special value USER_NUMBER_ALIAS in the identifier half of the
  72      identifier-symbol pair for an alias.  */
  73   symbol_t *alias;
  74   symbol_class class;
  75 };
  76
  77 /* Undefined user number.  */
  78 #define USER_NUMBER_UNDEFINED -1
  79
  80 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  81    *has* (not is) a string literal alias.  For instance, `%token foo
  82    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  83    USER_NUMBER_ALIAS.  */
  84 #define USER_NUMBER_ALIAS -9991
  85
  86 /* Undefined internal token number.  */
  87 #define NUMBER_UNDEFINED ((symbol_number_t) -1)
  88
  89
  90 /* Fetch (or create) the symbol associated to KEY.  */
  91 symbol_t *getsym PARAMS ((const char *key, location_t location));
  92
  93 /* Declare the new SYMBOL.  Make it an alias of SYMVAL.  */
  94 void symbol_make_alias PARAMS ((symbol_t *symbol, symbol_t *symval));
  95
  96 /* Set the TYPE_NAME associated to SYMBOL. Does nothing if passed 0 as
  97    TYPE_NAME.  */
  98 void symbol_type_set PARAMS ((symbol_t *symbol, char *type_name));
  99
 100 /* Set the PRECEDENCE associated to SYMBOL.  Ensures that SYMBOL is a
 101    terminal.  Does nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 102 void symbol_precedence_set PARAMS ((symbol_t *symbol,
 103                                     int prec, associativity assoc));
 104
 105 /* Set the CLASS associated to SYMBOL.  */
 106 void symbol_class_set PARAMS ((symbol_t *symbol, symbol_class class));
 107
 108 /* Set the USER_TOKEN_NUMBER associated to SYMBOL.  */
 109 void symbol_user_token_number_set PARAMS ((symbol_t *symbol, int user_number));
 110
 111
 112 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 113    by the automaton.  STARTSYMBOL is the one specified by the user.
 114    */
 115 extern symbol_t *errtoken;
 116 extern symbol_t *undeftoken;
 117 extern symbol_t *eoftoken;
 118 extern symbol_t *axiom;
 119 extern symbol_t *startsymbol;
 120 extern location_t startsymbol_location;
 121
 122
 123 /*---------------.
 124 | Symbol table.  |
 125 `---------------*/
 126
 127
 128 /* Create the symbol table.  */
 129 void symbols_new PARAMS ((void));
 130
 131 /* A function to apply to each symbol. */
 132 typedef bool (*symbol_processor) PARAMS ((symbol_t *));
 133
 134 /* Apply PROCESSOR to all the symbols.  PROCESSOR must return TRUE: on
 135    FALSE, the processing stops.  */
 136 void symbols_do PARAMS ((symbol_processor processor, void *processor_data));
 137
 138 /* Free all the memory allocated for symbols.  */
 139 void symbols_free PARAMS ((void));
 140
 141 /* Check that all the symbols are defined.  Report any undefined
 142    symbols and consider them nonterminals.  */
 143 void symbols_check_defined PARAMS ((void));
 144
 145 /* Perform various sanity checks, assign symbol numbers, and set up
 146    TOKEN_TRANSLATIONS.  */
 147 void symbols_pack PARAMS ((void));
 148
 149 #endif /* !SYMTAB_H_ */