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, 2008
   4    Free Software Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program 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 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 /**
  22  * \file symtab.h
  23  * \brief Manipulating ::symbol.
  24  */
  25
  26 #ifndef SYMTAB_H_
  27 # define SYMTAB_H_
  28
  29 # include "assoc.h"
  30 # include "location.h"
  31 # include "scan-code.h"
  32 # include "uniqstr.h"
  33
  34 /*----------.
  35 | Symbols.  |
  36 `----------*/
  37
  38 /** Symbol classes.  */
  39 typedef enum
  40 {
  41   unknown_sym,          /**< Undefined.  */
  42   token_sym,            /**< Terminal. */
  43   nterm_sym             /**< Non-terminal. */
  44 } symbol_class;
  45
  46
  47 /** Internal token numbers. */
  48 typedef int symbol_number;
  49 #define SYMBOL_NUMBER_MAXIMUM INT_MAX
  50
  51
  52 typedef struct symbol symbol;
  53
  54 /* When extending this structure, be sure to complete
  55    symbol_check_alias_consistency.  */
  56 struct symbol
  57 {
  58   /** The key, name of the symbol.  */
  59   uniqstr tag;
  60   /** The location of its first occurrence.  */
  61   location location;
  62
  63   /** Its \c \%type.  */
  64   uniqstr type_name;
  65   /** Its \c \%type's location.  */
  66   location type_location;
  67
  68   /** Any \c \%destructor declared specifically for this symbol.
  69
  70      Access this field only through <tt>symbol</tt>'s interface functions.  For
  71      example, if <tt>symbol::destructor = NULL</tt>, a default \c \%destructor
  72      or a per-type \c \%destructor might be appropriate, and
  73      \c symbol_destructor_get will compute the correct one.  */
  74   code_props destructor;
  75
  76   /** Any \c \%printer declared specifically for this symbol.
  77
  78      Access this field only through <tt>symbol</tt>'s interface functions.
  79      \sa symbol::destructor  */
  80   code_props printer;
  81
  82   symbol_number number;
  83   location prec_location;
  84   int prec;
  85   assoc assoc;
  86   int user_token_number;
  87
  88   /* Points to the other in the identifier-symbol pair for an alias.
  89      Special value USER_NUMBER_ALIAS in the identifier half of the
  90      identifier-symbol pair for an alias.  */
  91   symbol *alias;
  92   symbol_class class;
  93   bool declared;
  94 };
  95
  96 /** Undefined user number.  */
  97 #define USER_NUMBER_UNDEFINED -1
  98
  99 /* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
 100    *has* (not is) a string literal alias.  For instance, `%token foo
 101    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
 102    USER_NUMBER_ALIAS.  */
 103 #define USER_NUMBER_ALIAS -9991
 104
 105 /* Undefined internal token number.  */
 106 #define NUMBER_UNDEFINED (-1)
 107
 108 /** Fetch (or create) the symbol associated to KEY.  */
 109 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 110
 111 /** Fetch (or create) the symbol associated to KEY.  */
 112 symbol *symbol_get (const char *key, location loc);
 113
 114 /** Generate a dummy nonterminal.
 115
 116    Its name cannot conflict with the user's names.  */
 117 symbol *dummy_symbol_get (location loc);
 118
 119
 120 /*--------------------.
 121 | Methods on symbol.  |
 122 `--------------------*/
 123
 124 /** Print a symbol (for debugging). */
 125 void symbol_print (symbol *s, FILE *f);
 126
 127 /** Is this a dummy nonterminal?  */
 128 bool symbol_is_dummy (const symbol *sym);
 129
 130 /** Return the name of the symbol that can be used as an identifier.
 131  ** Consider the alias if needed.
 132  ** Return 0 if there is none (e.g., the symbol is only defined as
 133  ** a string). */
 134 uniqstr symbol_id_get (symbol const *sym);
 135
 136 /** Declare the new symbol \c sym.  Make it an alias of \c symval.  */
 137 void symbol_make_alias (symbol *sym, symbol *symval, location loc);
 138
 139 /** Set the \c type_name associated with \c sym.
 140
 141     Do nothing if passed 0 as \c type_name.  */
 142 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 143
 144 /** Get the \c class string associated with \c sym.  */
 145 const char *symbol_class_get_string (symbol *sym);
 146
 147 /** Set the \c destructor associated with \c sym.  */
 148 void symbol_destructor_set (symbol *sym, code_props const *destructor);
 149
 150 /** Get the computed \c \%destructor for \c sym, which was initialized with
 151     \c code_props_none_init if there's no \c \%destructor.  */
 152 code_props const *symbol_destructor_get (symbol const *sym);
 153
 154 /** Set the \c printer associated with \c sym.  */
 155 void symbol_printer_set (symbol *sym, code_props const *printer);
 156
 157 /** Get the computed \c \%printer for \c sym, which was initialized with
 158     \c code_props_none_init if there's no \c \%printer.  */
 159 code_props const *symbol_printer_get (symbol const *sym);
 160
 161 /* Set the \c precedence associated with \c sym.
 162
 163    Ensure that \a symbol is a terminal.
 164    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 165 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 166
 167 /** Set the \c class associated with \c sym.  */
 168 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 169                        bool declaring);
 170
 171 /** Set the \c user_token_number associated with \c sym.  */
 172 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 173
 174
 175
 176 /*------------------.
 177 | Special symbols.  |
 178 `------------------*/
 179
 180 /** The error token. */
 181 extern symbol *errtoken;
 182 /** The token for unknown tokens.  */
 183 extern symbol *undeftoken;
 184 /** The end of input token.  */
 185 extern symbol *endtoken;
 186 /** The genuine start symbol.
 187
 188    $accept: start-symbol $end */
 189 extern symbol *accept;
 190
 191 /** The user start symbol. */
 192 extern symbol *startsymbol;
 193 /** The location of the \c \%start declaration.  */
 194 extern location startsymbol_location;
 195
 196
 197 /*-----------------.
 198 | Semantic types.  |
 199 `-----------------*/
 200
 201 /** A semantic type and its associated \c \%destructor and \c \%printer.
 202
 203    Access the fields of this struct only through the interface functions in
 204    this file.  \sa symbol::destructor  */
 205 typedef struct {
 206   /** The key, name of the semantic type.  */
 207   uniqstr tag;
 208
 209   /** Any \c %destructor declared for this semantic type.  */
 210   code_props destructor;
 211   /** Any \c %printer declared for this semantic type.  */
 212   code_props printer;
 213 } semantic_type;
 214
 215 /** Fetch (or create) the semantic type associated to KEY.  */
 216 semantic_type *semantic_type_from_uniqstr (const uniqstr key);
 217
 218 /** Fetch (or create) the semantic type associated to KEY.  */
 219 semantic_type *semantic_type_get (const char *key);
 220
 221 /** Set the \c destructor associated with \c type.  */
 222 void semantic_type_destructor_set (semantic_type *type,
 223                                    code_props const *destructor);
 224
 225 /** Set the \c printer associated with \c type.  */
 226 void semantic_type_printer_set (semantic_type *type,
 227                                 code_props const *printer);
 228
 229 /*----------------------------------.
 230 | Symbol and semantic type tables.  |
 231 `----------------------------------*/
 232
 233 /** Create the symbol and semantic type tables.  */
 234 void symbols_new (void);
 235
 236 /** Free all the memory allocated for symbols and semantic types.  */
 237 void symbols_free (void);
 238
 239 /** Check that all the symbols are defined.
 240
 241     Report any undefined symbols and consider them nonterminals.  */
 242 void symbols_check_defined (void);
 243
 244 /** Sanity checks and #token_translations construction.
 245
 246    Perform various sanity checks, assign symbol numbers, and set up
 247    #token_translations.  */
 248 void symbols_pack (void);
 249
 250
 251 /*---------------------------------------.
 252 | Default %destructor's and %printer's.  |
 253 `---------------------------------------*/
 254
 255 /** Set the default \c \%destructor for tagged values.  */
 256 void default_tagged_destructor_set (code_props const *destructor);
 257 /** Set the default \c \%destructor for tagless values.  */
 258 void default_tagless_destructor_set (code_props const *destructor);
 259
 260 /** Set the default \c \%printer for tagged values.  */
 261 void default_tagged_printer_set (code_props const *printer);
 262 /** Set the default \c \%printer for tagless values.  */
 263 void default_tagless_printer_set (code_props const *printer);
 264
 265 #endif /* !SYMTAB_H_ */