symtab.h revision 05436638acc7c010349a69c3395f1a57c642dc62 
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.  */
39typedef enum
40{
41  unknown_sym,          /**< Undefined.  */
42  token_sym,		/**< Terminal. */
43  nterm_sym		/**< Non-terminal. */
44} symbol_class;
45
46
47/** Internal token numbers. */
48typedef int symbol_number;
49#define SYMBOL_NUMBER_MAXIMUM INT_MAX
50
51
52typedef struct symbol symbol;
53
54/* When extending this structure, be sure to complete
55   symbol_check_alias_consistency.  */
56struct 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). */
116void symbol_print (symbol *s, FILE *f);
117
118/** Fetch (or create) the symbol associated to KEY.  */
119symbol *symbol_from_uniqstr (const uniqstr key, location loc);
120
121/** Fetch (or create) the symbol associated to KEY.  */
122symbol *symbol_get (const char *key, location loc);
123
124/** Generate a dummy nonterminal.
125
126   Its name cannot conflict with the user's names.  */
127symbol *dummy_symbol_get (location loc);
128
129/** Is this a dummy nonterminal?  */
130bool 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 */
136void 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.  */
141void symbol_type_set (symbol *sym, uniqstr type_name, location loc);
142
143/** Set the \c destructor associated with \c sym.  */
144void 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.  */
148code_props const *symbol_destructor_get (symbol const *sym);
149
150/** Set the \c printer associated with \c sym.  */
151void 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.  */
155code_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.  */
161void symbol_precedence_set (symbol *sym, int prec, assoc a, location loc);
162
163/** Set the \c class associated with \c sym.  */
164void 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.  */
168void symbol_user_token_number_set (symbol *sym, int user_number, location loc);
169
170
171/** The error token. */
172extern symbol *errtoken;
173/** The token for unknown tokens.  */
174extern symbol *undeftoken;
175/** The end of input token.  */
176extern symbol *endtoken;
177/** The genuine start symbol.
178
179   $accept: start-symbol $end */
180extern symbol *accept;
181
182/** The user start symbol. */
183extern symbol *startsymbol;
184/** The location of the \c \%start declaration.  */
185extern 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  */
196typedef 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.  */
207semantic_type *semantic_type_from_uniqstr (const uniqstr key);
208
209/** Fetch (or create) the semantic type associated to KEY.  */
210semantic_type *semantic_type_get (const char *key);
211
212/** Set the \c destructor associated with \c type.  */
213void semantic_type_destructor_set (semantic_type *type,
214                                   code_props const *destructor);
215
216/** Set the \c printer associated with \c type.  */
217void 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.  */
225void symbols_new (void);
226
227/** Free all the memory allocated for symbols and semantic types.  */
228void symbols_free (void);
229
230/** Check that all the symbols are defined.
231
232    Report any undefined symbols and consider them nonterminals.  */
233void 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.  */
239void symbols_pack (void);
240
241
242/*---------------------------------------.
243| Default %destructor's and %printer's.  |
244`---------------------------------------*/
245
246/** Set the default \c \%destructor for tagged values.  */
247void default_tagged_destructor_set (code_props const *destructor);
248/** Set the default \c \%destructor for tagless values.  */
249void default_tagless_destructor_set (code_props const *destructor);
250
251/** Set the default \c \%printer for tagged values.  */
252void default_tagged_printer_set (code_props const *printer);
253/** Set the default \c \%printer for tagless values.  */
254void default_tagless_printer_set (code_props const *printer);
255
256#endif /* !SYMTAB_H_ */
257