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