src/symtab.h

   1 /* Definitions for symtab.c and callers, part of Bison.
   2
   3    Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004, 2005, 2006, 2007
   4    Free Software Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    Bison is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    Bison is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with Bison; see the file COPYING.  If not, write to
  20    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 /**
  24  * \file symtab.h
  25  * \brief Manipulating ::symbol.
  26  */
  27
  28 #ifndef SYMTAB_H_
  29 # define SYMTAB_H_
  30
  31 # include "assoc.h"
  32 # include "location.h"
  33 # include "scan-code.h"
  34 # include "uniqstr.h"
  35
  36 /*----------.
  37 | Symbols.  |
  38 `----------*/
  39
  40 /** Symbol classes.  */
  41 typedef enum
  42 {
  43   unknown_sym,          /**< Undefined.  */
  44   token_sym,            /**< Terminal. */
  45   nterm_sym             /**< Non-terminal. */
  46 } symbol_class;
  47
  48
  49 /** Internal token numbers. */
  50 typedef int symbol_number;
  51 #define SYMBOL_NUMBER_MAXIMUM INT_MAX
  52
  53
  54 typedef struct symbol symbol;
  55
  56 /* When extending this structure, be sure to complete
  57    symbol_check_alias_consistency.  */
  58 struct symbol
  59 {
  60   /** The key, name of the symbol.  */
  61   uniqstr tag;
  62   /** The location of its first occurrence.  */
  63   location location;
  64
  65   /** Its \c \%type.  */
  66   uniqstr type_name;
  67   /** Its \c \%type's location.  */
  68   location type_location;
  69
  70   /** Any \c \%destructor declared specifically for this symbol.
  71
  72      Access this field only through <tt>symbol</tt>'s interface functions.  For
  73      example, if <tt>symbol::destructor = NULL</tt>, a default \c \%destructor
  74      or a per-type \c \%destructor might be appropriate, and
  75      \c symbol_destructor_get will compute the correct one.  */
  76   code_props destructor;
  77
  78   /** Any \c \%printer declared specifically for this symbol.
  79
  80      Access this field only through <tt>symbol</tt>'s interface functions.
  81      \sa symbol::destructor  */
  82   code_props printer;
  83
  84   symbol_number number;
  85   location prec_location;
  86   int prec;
  87   assoc assoc;
  88   int user_token_number;
  89
  90   /* Points to the other in the identifier-symbol pair for an alias.
  91      Special value USER_NUMBER_ALIAS in the identifier half of the
  92      identifier-symbol pair for an alias.  */
  93   symbol *alias;
  94   symbol_class class;
  95   bool declared;
  96 };
  97
  98 /** Undefined user number.  */
  99 #define USER_NUMBER_UNDEFINED -1
 100
 101 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
 102    *has* (not is) a string literal alias.  For instance, `%token foo
 103    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
 104    USER_NUMBER_ALIAS.  */
 105 #define USER_NUMBER_ALIAS -9991
 106
 107 /* Undefined internal token number.  */
 108 #define NUMBER_UNDEFINED (-1)
 109
 110 /** Print a symbol (for debugging). */
 111 void symbol_print (symbol *s, FILE *f);
 112
 113 /** Fetch (or create) the symbol associated to KEY.  */
 114 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 115
 116 /** Fetch (or create) the symbol associated to KEY.  */
 117 symbol *symbol_get (const char *key, location loc);
 118
 119 /** Generate a dummy nonterminal.
 120
 121    Its name cannot conflict with the user's names.  */
 122 symbol *dummy_symbol_get (location loc);
 123
 124 /** Is this a dummy nonterminal?  */
 125 bool symbol_is_dummy (const symbol *sym);
 126
 127 /** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
 128 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 129
 130 /** Set the \c type_name associated with \c sym.
 131
 132     Do nothing if passed 0 as \c type_name.  */
 133 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 134
 135 /** Set the \c destructor associated with \c sym.  */
 136 void symbol_destructor_set (symbol *sym, code_props const *destructor);
 137
 138 /** Get the computed \c \%destructor for \c sym, which was initialized with
 139     \c code_props_none_init if there's no \c \%destructor.  */
 140 code_props const *symbol_destructor_get (symbol const *sym);
 141
 142 /** Set the \c printer associated with \c sym.  */
 143 void symbol_printer_set (symbol *sym, code_props const *printer);
 144
 145 /** Get the computed \c \%printer for \c sym, which was initialized with
 146     \c code_props_none_init if there's no \c \%printer.  */
 147 code_props const *symbol_printer_get (symbol const *sym);
 148
 149 /* Set the \c precedence associated with \c sym.
 150
 151    Ensure that \a symbol is a terminal.
 152    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 153 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 154
 155 /** Set the \c class associated with \c sym.  */
 156 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 157                        bool declaring);
 158
 159 /** Set the \c user_token_number associated with \c sym.  */
 160 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 161
 162
 163 /** The error token. */
 164 extern symbol *errtoken;
 165 /** The token for unknown tokens.  */
 166 extern symbol *undeftoken;
 167 /** The end of input token.  */
 168 extern symbol *endtoken;
 169 /** The genuine start symbol.
 170
 171    $accept: start-symbol $end */
 172 extern symbol *accept;
 173
 174 /** The user start symbol. */
 175 extern symbol *startsymbol;
 176 /** The location of the \c \%start declaration.  */
 177 extern location startsymbol_location;
 178
 179
 180 /*-----------------.
 181 | Semantic types.  |
 182 `-----------------*/
 183
 184 /** A semantic type and its associated \c \%destructor and \c \%printer.
 185
 186    Access the fields of this struct only through the interface functions in
 187    this file.  \sa symbol::destructor  */
 188 typedef struct {
 189   /** The key, name of the semantic type.  */
 190   uniqstr tag;
 191
 192   /** Any \c %destructor declared for this semantic type.  */
 193   code_props destructor;
 194   /** Any \c %printer declared for this semantic type.  */
 195   code_props printer;
 196 } semantic_type;
 197
 198 /** Fetch (or create) the semantic type associated to KEY.  */
 199 semantic_type *semantic_type_from_uniqstr (const uniqstr key);
 200
 201 /** Fetch (or create) the semantic type associated to KEY.  */
 202 semantic_type *semantic_type_get (const char *key);
 203
 204 /** Set the \c destructor associated with \c type.  */
 205 void semantic_type_destructor_set (semantic_type *type,
 206                                    code_props const *destructor);
 207
 208 /** Set the \c printer associated with \c type.  */
 209 void semantic_type_printer_set (semantic_type *type,
 210                                 code_props const *printer);
 211
 212 /*----------------------------------.
 213 | Symbol and semantic type tables.  |
 214 `----------------------------------*/
 215
 216 /** Create the symbol and semantic type tables.  */
 217 void symbols_new (void);
 218
 219 /** Free all the memory allocated for symbols and semantic types.  */
 220 void symbols_free (void);
 221
 222 /** Check that all the symbols are defined.
 223
 224     Report any undefined symbols and consider them nonterminals.  */
 225 void symbols_check_defined (void);
 226
 227 /** Sanity checks and #token_translations construction.
 228
 229    Perform various sanity checks, assign symbol numbers, and set up
 230    #token_translations.  */
 231 void symbols_pack (void);
 232
 233
 234 /*---------------------------------------.
 235 | Default %destructor's and %printer's.  |
 236 `---------------------------------------*/
 237
 238 /** Set the default \c \%destructor for tagged values.  */
 239 void default_tagged_destructor_set (code_props const *destructor);
 240 /** Set the default \c \%destructor for tagless values.  */
 241 void default_tagless_destructor_set (code_props const *destructor);
 242
 243 /** Set the default \c \%printer for tagged values.  */
 244 void default_tagged_printer_set (code_props const *printer);
 245 /** Set the default \c \%printer for tagless values.  */
 246 void default_tagless_printer_set (code_props const *printer);
 247
 248 #endif /* !SYMTAB_H_ */