src/symtab.h

   1 /* Definitions for symtab.c and callers, part of Bison.
   2
   3    Copyright (C) 1984, 1989, 1992, 2000-2002, 2004-2007, 2009-2012 Free
   4    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
  65       Beware that this is the type_name as was entered by the user,
  66       including silly things such as "]" if she entered "%token <]> t".
  67       Therefore, when outputting type_name to M4, be sure to escape it
  68       into "@}".  See quoted_output for instance.  */
  69   uniqstr type_name;
  70
  71   /** Its \c \%type's location.  */
  72   location type_location;
  73
  74   /** Any \c \%destructor declared specifically for this symbol.
  75
  76       Access this field only through <tt>symbol</tt>'s interface
  77       functions.  For example, if <tt>symbol::destructor = NULL</tt>, a
  78       default \c \%destructor or a per-type \c \%destructor might be
  79       appropriate, and \c symbol_destructor_get will compute the
  80       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   bool declared;
 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 /** Print a symbol (for debugging). */
 116 void symbol_print (symbol *s, FILE *f);
 117
 118 /** Fetch (or create) the symbol associated to KEY.  */
 119 symbol *symbol_from_uniqstr (const uniqstr key, location loc);
 120
 121 /** Fetch (or create) the symbol associated to KEY.  */
 122 symbol *symbol_get (const char *key, location loc);
 123
 124 /** Generate a dummy nonterminal.
 125
 126    Its name cannot conflict with the user's names.  */
 127 symbol *dummy_symbol_get (location loc);
 128
 129 /** Is this a dummy nonterminal?  */
 130 bool symbol_is_dummy (const symbol *sym);
 131
 132 /**
 133  * Make \c str the literal string alias of \c sym.  Copy token number,
 134  * symbol number, and type from \c sym to \c str.
 135  */
 136 void symbol_make_alias (symbol *sym, symbol *str, location loc);
 137
 138 /** Set the \c type_name associated with \c sym.
 139
 140     Do nothing if passed 0 as \c type_name.  */
 141 void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
 142
 143 /** Set the \c destructor associated with \c sym.  */
 144 void symbol_destructor_set (symbol *sym, code_props const *destructor);
 145
 146 /** Get the computed \c \%destructor for \c sym, which was initialized with
 147     \c code_props_none_init if there's no \c \%destructor.  */
 148 code_props const *symbol_destructor_get (symbol const *sym);
 149
 150 /** Set the \c printer associated with \c sym.  */
 151 void symbol_printer_set (symbol *sym, code_props const *printer);
 152
 153 /** Get the computed \c \%printer for \c sym, which was initialized with
 154     \c code_props_none_init if there's no \c \%printer.  */
 155 code_props const *symbol_printer_get (symbol const *sym);
 156
 157 /* Set the \c precedence associated with \c sym.
 158
 159    Ensure that \a symbol is a terminal.
 160    Do nothing if invoked with \c undef_assoc as \c assoc.  */
 161 void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
 162
 163 /** Set the \c class associated with \c sym.  */
 164 void symbol_class_set (symbol *sym, symbol_class class, location loc,
 165                        bool declaring);
 166
 167 /** Set the \c user_token_number associated with \c sym.  */
 168 void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
 169
 170
 171 /** The error token. */
 172 extern symbol *errtoken;
 173 /** The token for unknown tokens.  */
 174 extern symbol *undeftoken;
 175 /** The end of input token.  */
 176 extern symbol *endtoken;
 177 /** The genuine start symbol.
 178
 179    $accept: start-symbol $end */
 180 extern symbol *accept;
 181
 182 /** The user start symbol. */
 183 extern symbol *startsymbol;
 184 /** The location of the \c \%start declaration.  */
 185 extern location startsymbol_location;
 186
 187
 188 /*-----------------.
 189 | Semantic types.  |
 190 `-----------------*/
 191
 192 /** A semantic type and its associated \c \%destructor and \c \%printer.
 193
 194    Access the fields of this struct only through the interface functions in
 195    this file.  \sa symbol::destructor  */
 196 typedef struct {
 197   /** The key, name of the semantic type.  */
 198   uniqstr tag;
 199
 200   /** Any \c %destructor declared for this semantic type.  */
 201   code_props destructor;
 202   /** Any \c %printer declared for this semantic type.  */
 203   code_props printer;
 204 } semantic_type;
 205
 206 /** Fetch (or create) the semantic type associated to KEY.  */
 207 semantic_type *semantic_type_from_uniqstr (const uniqstr key);
 208
 209 /** Fetch (or create) the semantic type associated to KEY.  */
 210 semantic_type *semantic_type_get (const char *key);
 211
 212 /** Set the \c destructor associated with \c type.  */
 213 void semantic_type_destructor_set (semantic_type *type,
 214                                    code_props const *destructor);
 215
 216 /** Set the \c printer associated with \c type.  */
 217 void semantic_type_printer_set (semantic_type *type,
 218                                 code_props const *printer);
 219
 220 /*----------------------------------.
 221 | Symbol and semantic type tables.  |
 222 `----------------------------------*/
 223
 224 /** Create the symbol and semantic type tables.  */
 225 void symbols_new (void);
 226
 227 /** Free all the memory allocated for symbols and semantic types.  */
 228 void symbols_free (void);
 229
 230 /** Check that all the symbols are defined.
 231
 232     Report any undefined symbols and consider them nonterminals.  */
 233 void symbols_check_defined (void);
 234
 235 /** Sanity checks and #token_translations construction.
 236
 237    Perform various sanity checks, assign symbol numbers, and set up
 238    #token_translations.  */
 239 void symbols_pack (void);
 240
 241
 242 /*---------------------------------------.
 243 | Default %destructor's and %printer's.  |
 244 `---------------------------------------*/
 245
 246 /** Set the default \c \%destructor for tagged values.  */
 247 void default_tagged_destructor_set (code_props const *destructor);
 248 /** Set the default \c \%destructor for tagless values.  */
 249 void default_tagless_destructor_set (code_props const *destructor);
 250
 251 /** Set the default \c \%printer for tagged values.  */
 252 void default_tagged_printer_set (code_props const *printer);
 253 /** Set the default \c \%printer for tagless values.  */
 254 void default_tagless_printer_set (code_props const *printer);
 255
 256 #endif /* !SYMTAB_H_ */