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