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 "assoc.h"
  26 # include "location.h"
  27 # include "uniqstr.h"
  28
  29 /*----------.
  30 | Symbols.  |
  31 `----------*/
  32
  33 /* Symbol classes.  */
  34 typedef enum
  35 {
  36   unknown_sym,
  37   token_sym,            /* terminal symbol */
  38   nterm_sym             /* non-terminal */
  39 } symbol_class;
  40
  41
  42 /* Internal token numbers. */
  43 typedef short symbol_number;
  44 #define SYMBOL_NUMBER_MAXIMUM SHRT_MAX
  45
  46
  47 typedef struct symbol symbol;
  48 struct symbol
  49 {
  50   /* The key, name of the symbol.  */
  51   uniqstr tag;
  52   /* The location of its first occurrence.  */
  53   location location;
  54
  55   /* Its %type and associated printer and destructor.  */
  56   uniqstr type_name;
  57   char *destructor;
  58   location destructor_location;
  59   char *printer;
  60   location printer_location;
  61
  62   symbol_number number;
  63   short prec;
  64   assoc assoc;
  65   int user_token_number;
  66
  67   /* Points to the other in the identifier-symbol pair for an alias.
  68      Special value USER_NUMBER_ALIAS in the identifier half of the
  69      identifier-symbol pair for an alias.  */
  70   symbol *alias;
  71   symbol_class class;
  72 };
  73
  74 /* Undefined user number.  */
  75 #define USER_NUMBER_UNDEFINED -1
  76
  77 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
  78    *has* (not is) a string literal alias.  For instance, `%token foo
  79    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
  80    USER_NUMBER_ALIAS.  */
  81 #define USER_NUMBER_ALIAS -9991
  82
  83 /* Undefined internal token number.  */
  84 #define NUMBER_UNDEFINED ((symbol_number) -1)
  85
  86
  87 /* Fetch (or create) the symbol associated to KEY.  */
  88 symbol *symbol_get (const char *key, location loc);
  89
  90 /* Generate a dummy nonterminal, whose name cannot conflict with the
  91    user's names.  */
  92 symbol *dummy_symbol_get (location loc);
  93
  94 /* Declare the new symbol SYM.  Make it an alias of SYMVAL.  */
  95 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
  96
  97 /* Set the TYPE_NAME associated with SYM.  Do nothing if passed 0 as
  98    TYPE_NAME.  */
  99 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 100
 101 /* Set the DESTRUCTOR associated with SYM.  */
 102 void symbol_destructor_set (symbol *sym, char *destructor, location loc);
 103
 104 /* Set the PRINTER associated with SYM.  */
 105 void symbol_printer_set (symbol *sym, char *printer, location loc);
 106
 107 /* Set the PRECEDENCE associated with SYM.  Ensure that SYMBOL is a
 108    terminal.  Do nothing if invoked with UNDEF_ASSOC as ASSOC.  */
 109 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 110
 111 /* Set the CLASS associated with SYM.  */
 112 void symbol_class_set (symbol *sym, symbol_class class, location loc);
 113
 114 /* Set the USER_TOKEN_NUMBER associated with SYM.  */
 115 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 116
 117
 118 /* Distinguished symbols.  AXIOM is the real start symbol, that used
 119    by the automaton.  STARTSYMBOL is the one specified by the user.
 120    */
 121 extern symbol *errtoken;
 122 extern symbol *undeftoken;
 123 extern symbol *endtoken;
 124 extern symbol *accept;
 125 extern symbol *startsymbol;
 126 extern location startsymbol_location;
 127
 128
 129 /*---------------.
 130 | Symbol table.  |
 131 `---------------*/
 132
 133
 134 /* Create the symbol table.  */
 135 void symbols_new (void);
 136
 137 /* A function to apply to each symbol. */
 138 typedef bool (*symbol_processor) (symbol *);
 139
 140 /* Apply PROCESSOR to all the symbols.  PROCESSOR must return true: on
 141    false, the processing stops.  */
 142 void symbols_do (symbol_processor processor, void *processor_data);
 143
 144 /* Free all the memory allocated for symbols.  */
 145 void symbols_free (void);
 146
 147 /* Check that all the symbols are defined.  Report any undefined
 148    symbols and consider them nonterminals.  */
 149 void symbols_check_defined (void);
 150
 151 /* Perform various sanity checks, assign symbol numbers, and set up
 152    TOKEN_TRANSLATIONS.  */
 153 void symbols_pack (void);
 154
 155 #endif /* !SYMTAB_H_ */