src/symtab.h

   1 /* Definitions for symtab.c and callers, part of Bison.
   2
   3    Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2012 Free Software
   4    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 /* Declaration status of a symbol.
  55
  56    First, it is "undeclared".  Then, if "undeclared" and used in a
  57    %printer/%destructor, it is "used".  If not "declared" by used in a
  58    rule, it is "needed".  Finally, if declared (via a rule for
  59    nonterminals, or %oken), it is "declared".
  60
  61    When status are checked at the end, "declared" symbols are fine,
  62    "used" symbols trigger warnings, otherwise it's an error.
  63 */
  64
  65 typedef enum
  66   {
  67     /** Used in the input file for an unknown reason (error).  */
  68     undeclared,
  69     /** Used by %destructor/%printer but not defined (warning).  */
  70     used,
  71     /** Used in the gramar (rules) but not defined (error).  */
  72     needed,
  73     /** Defined with %type or %token (good).  */
  74     declared,
  75   } status;
  76
  77 /* When extending this structure, be sure to complete
  78    symbol_check_alias_consistency.  */
  79 struct symbol
  80 {
  81   /** The key, name of the symbol.  */
  82   uniqstr tag;
  83   /** The location of its first occurrence.  */
  84   location location;
  85
  86   /** Its \c \%type.  */
  87   uniqstr type_name;
  88   /** Its \c \%type's location.  */
  89   location type_location;
  90
  91   /** Any \c \%destructor declared specifically for this symbol.
  92
  93      Access this field only through <tt>symbol</tt>'s interface functions.  For
  94      example, if <tt>symbol::destructor = NULL</tt>, a default \c \%destructor
  95      or a per-type \c \%destructor might be appropriate, and
  96      \c symbol_destructor_get will compute the correct one.  */
  97   code_props destructor;
  98
  99   /** Any \c \%printer declared specifically for this symbol.
 100
 101      Access this field only through <tt>symbol</tt>'s interface functions.
 102      \sa symbol::destructor  */
 103   code_props printer;
 104
 105   symbol_number number;
 106   location prec_location;
 107   int prec;
 108   assoc assoc;
 109   int user_token_number;
 110
 111   /* Points to the other in the symbol-string pair for an alias.
 112      Special value USER_NUMBER_HAS_STRING_ALIAS in the symbol half of the
 113      symbol-string pair for an alias.  */
 114   symbol *alias;
 115   symbol_class class;
 116   status status;
 117 };
 118
 119 /** Undefined user number.  */
 120 #define USER_NUMBER_UNDEFINED -1
 121
 122 /* `symbol->user_token_number == USER_NUMBER_HAS_STRING_ALIAS' means
 123    this symbol has a literal string alias.  For instance, `%token foo
 124    "foo"' has `"foo"' numbered regularly, and `foo' numbered as
 125    USER_NUMBER_HAS_STRING_ALIAS.  */
 126 #define USER_NUMBER_HAS_STRING_ALIAS -9991
 127
 128 /* Undefined internal token number.  */
 129 #define NUMBER_UNDEFINED (-1)
 130
 131 /** Fetch (or create) the symbol associated to KEY.  */
 132 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 133
 134 /** Fetch (or create) the symbol associated to KEY.  */
 135 symbol *symbol_get (const char *key, location loc);
 136
 137 /** Generate a dummy nonterminal.
 138
 139    Its name cannot conflict with the user's names.  */
 140 symbol *dummy_symbol_get (location loc);
 141
 142
 143 /*--------------------.
 144 | Methods on symbol.  |
 145 `--------------------*/
 146
 147 /** Print a symbol (for debugging). */
 148 void symbol_print (symbol *s, FILE *f);
 149
 150 /** Is this a dummy nonterminal?  */
 151 bool symbol_is_dummy (const symbol *sym);
 152
 153 /** Return the name of the symbol that can be used as an identifier.
 154  ** Consider the alias if needed.
 155  ** Return 0 if there is none (e.g., the symbol is only defined as
 156  ** a string). */
 157 uniqstr symbol_id_get (symbol const *sym);
 158
 159 /**
 160  * Make \c str the literal string alias of \c sym.  Copy token number,
 161  * symbol number, and type from \c sym to \c str.
 162  */
 163 void symbol_make_alias (symbol *sym, symbol *str, location loc);
 164
 165 /** Set the \c type_name associated with \c sym.
 166
 167     Do nothing if passed 0 as \c type_name.  */
 168 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 169
 170 /** Set the \c destructor associated with \c sym.  */
 171 void symbol_destructor_set (symbol *sym, code_props const *destructor);
 172
 173 /** Get the computed \c \%destructor for \c sym, which was initialized with
 174     \c code_props_none_init if there's no \c \%destructor.  */
 175 code_props const *symbol_destructor_get (symbol const *sym);
 176
 177 /** Set the \c printer associated with \c sym.  */
 178 void symbol_printer_set (symbol *sym, code_props const *printer);
 179
 180 /** Get the computed \c \%printer for \c sym, which was initialized with
 181     \c code_props_none_init if there's no \c \%printer.  */
 182 code_props const *symbol_printer_get (symbol const *sym);
 183
 184 /* Set the \c precedence associated with \c sym.
 185
 186    Ensure that \a symbol is a terminal.
 187    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 188 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 189
 190 /** Set the \c class associated with \c sym.  */
 191 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 192                        bool declaring);
 193
 194 /** Set the \c user_token_number associated with \c sym.  */
 195 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 196
 197
 198
 199 /*------------------.
 200 | Special symbols.  |
 201 `------------------*/
 202
 203 /** The error token. */
 204 extern symbol *errtoken;
 205 /** The token for unknown tokens.  */
 206 extern symbol *undeftoken;
 207 /** The end of input token.  */
 208 extern symbol *endtoken;
 209 /** The genuine start symbol.
 210
 211    $accept: start-symbol $end */
 212 extern symbol *accept;
 213
 214 /** The user start symbol. */
 215 extern symbol *startsymbol;
 216 /** The location of the \c \%start declaration.  */
 217 extern location startsymbol_location;
 218
 219
 220 /*-----------------.
 221 | Semantic types.  |
 222 `-----------------*/
 223
 224 /** A semantic type and its associated \c \%destructor and \c \%printer.
 225
 226    Access the fields of this struct only through the interface functions in
 227    this file.  \sa symbol::destructor  */
 228 typedef struct {
 229   /** The key, name of the semantic type.  */
 230   uniqstr tag;
 231
 232   /** Any \c %destructor declared for this semantic type.  */
 233   code_props destructor;
 234   /** Any \c %printer declared for this semantic type.  */
 235   code_props printer;
 236 } semantic_type;
 237
 238 /** Fetch (or create) the semantic type associated to KEY.  */
 239 semantic_type *semantic_type_from_uniqstr (const uniqstr key);
 240
 241 /** Fetch (or create) the semantic type associated to KEY.  */
 242 semantic_type *semantic_type_get (const char *key);
 243
 244 /** Set the \c destructor associated with \c type.  */
 245 void semantic_type_destructor_set (semantic_type *type,
 246                                    code_props const *destructor);
 247
 248 /** Set the \c printer associated with \c type.  */
 249 void semantic_type_printer_set (semantic_type *type,
 250                                 code_props const *printer);
 251
 252 /*----------------------------------.
 253 | Symbol and semantic type tables.  |
 254 `----------------------------------*/
 255
 256 /** Create the symbol and semantic type tables.  */
 257 void symbols_new (void);
 258
 259 /** Free all the memory allocated for symbols and semantic types.  */
 260 void symbols_free (void);
 261
 262 /** Check that all the symbols are defined.
 263
 264     Report any undefined symbols and consider them nonterminals.  */
 265 void symbols_check_defined (void);
 266
 267 /** Sanity checks and #token_translations construction.
 268
 269    Perform various sanity checks, assign symbol numbers, and set up
 270    #token_translations.  */
 271 void symbols_pack (void);
 272
 273
 274 /*---------------------------------------.
 275 | Default %destructor's and %printer's.  |
 276 `---------------------------------------*/
 277
 278 /** Set the default \c \%destructor for tagged values.  */
 279 void default_tagged_destructor_set (code_props const *destructor);
 280 /** Set the default \c \%destructor for tagless values.  */
 281 void default_tagless_destructor_set (code_props const *destructor);
 282
 283 /** Set the default \c \%printer for tagged values.  */
 284 void default_tagged_printer_set (code_props const *printer);
 285 /** Set the default \c \%printer for tagless values.  */
 286 void default_tagless_printer_set (code_props const *printer);
 287
 288 #endif /* !SYMTAB_H_ */