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