1/* Definitions for symtab.c and callers, part of Bison.
2
3   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2004, 2005, 2006
4   Free Software Foundation, Inc.
5
6   This file is part of Bison, the GNU Compiler Compiler.
7
8   Bison 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 2, or (at your option)
11   any later version.
12
13   Bison 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 Bison; see the file COPYING.  If not, write to
20   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21   Boston, MA 02110-1301, USA.  */
22
23#ifndef SYMTAB_H_
24# define SYMTAB_H_
25
26# include "assoc.h"
27# include "location.h"
28# include "uniqstr.h"
29
30/*----------.
31| Symbols.  |
32`----------*/
33
34/* Symbol classes.  */
35typedef enum
36{
37  unknown_sym,
38  token_sym,		/* terminal symbol */
39  nterm_sym		/* non-terminal */
40} symbol_class;
41
42
43/* Internal token numbers. */
44typedef int symbol_number;
45#define SYMBOL_NUMBER_MAXIMUM INT_MAX
46
47
48typedef struct symbol symbol;
49
50/* When extending this structure, be sure to complete
51   symbol_check_alias_consistency.  */
52struct symbol
53{
54  /* The key, name of the symbol.  */
55  uniqstr tag;
56  /* The location of its first occurrence.  */
57  location location;
58
59  /* Its %type and associated printer and destructor.  */
60  uniqstr type_name;
61  location type_location;
62
63  /* Does not own the memory. */
64  const char *destructor;
65  location destructor_location;
66
67  /* Does not own the memory. */
68  const char *printer;
69  location printer_location;
70
71  symbol_number number;
72  location prec_location;
73  int prec;
74  assoc assoc;
75  int user_token_number;
76
77  /* Points to the other in the identifier-symbol pair for an alias.
78     Special value USER_NUMBER_ALIAS in the identifier half of the
79     identifier-symbol pair for an alias.  */
80  symbol *alias;
81  symbol_class class;
82  bool declared;
83};
84
85/* Undefined user number.  */
86#define USER_NUMBER_UNDEFINED -1
87
88/* `symbol->user_token_number == USER_NUMBER_ALIAS' means this symbol
89   *has* (not is) a string literal alias.  For instance, `%token foo
90   "foo"' has `"foo"' numbered regularly, and `foo' numbered as
91   USER_NUMBER_ALIAS.  */
92#define USER_NUMBER_ALIAS -9991
93
94/* Undefined internal token number.  */
95#define NUMBER_UNDEFINED (-1)
96
97/* Print a symbol (for debugging). */
98void symbol_print (symbol *s, FILE *f);
99
100/* Fetch (or create) the symbol associated to KEY.  */
101symbol *symbol_get (const char *key, location loc);
102
103/* Generate a dummy nonterminal, whose name cannot conflict with the
104   user's names.  */
105symbol *dummy_symbol_get (location loc);
106
107/* Declare the new symbol SYM.  Make it an alias of SYMVAL.  */
108void symbol_make_alias (symbol *sym, symbol *symval, location loc);
109
110/* Set the TYPE_NAME associated with SYM.  Do nothing if passed 0 as
111   TYPE_NAME.  */
112void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
113
114/* Set the DESTRUCTOR associated with SYM.  */
115void symbol_destructor_set (symbol *sym, const char *destructor, location loc);
116
117/* Set the PRINTER associated with SYM.  */
118void symbol_printer_set (symbol *sym, const char *printer, location loc);
119
120/* Set the PRECEDENCE associated with SYM.  Ensure that SYMBOL is a
121   terminal.  Do nothing if invoked with UNDEF_ASSOC as ASSOC.  */
122void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
123
124/* Set the CLASS associated with SYM.  */
125void symbol_class_set (symbol *sym, symbol_class class, location loc,
126		       bool declaring);
127
128/* Set the USER_TOKEN_NUMBER associated with SYM.  */
129void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
130
131
132/* Distinguished symbols.  AXIOM is the real start symbol, that used
133   by the automaton.  STARTSYMBOL is the one specified by the user.
134   */
135extern symbol *errtoken;
136extern symbol *undeftoken;
137extern symbol *endtoken;
138extern symbol *accept;
139extern symbol *startsymbol;
140extern location startsymbol_location;
141
142
143/*---------------.
144| Symbol table.  |
145`---------------*/
146
147
148/* Create the symbol table.  */
149void symbols_new (void);
150
151/* Free all the memory allocated for symbols.  */
152void symbols_free (void);
153
154/* Check that all the symbols are defined.  Report any undefined
155   symbols and consider them nonterminals.  */
156void symbols_check_defined (void);
157
158/* Perform various sanity checks, assign symbol numbers, and set up
159   TOKEN_TRANSLATIONS.  */
160void symbols_pack (void);
161
162#endif /* !SYMTAB_H_ */
163