maint: remove unnecessary casts before using gnulib functions
[bison.git] / src / lalr.h
blob765e5c933f7a16bb329168938dcf45457c521d8d
1 /* Compute lookahead criteria for bison,
3 Copyright (C) 1984, 1986, 1989, 2000, 2002, 2004, 2006-2007,
4 2009-2015, 2018-2022 Free Software Foundation, Inc.
6 This file is part of Bison, the GNU Compiler Compiler.
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.
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.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <https://www.gnu.org/licenses/>. */
21 #ifndef LALR_H_
22 # define LALR_H_
24 # include <bitset.h>
25 # include <bitsetv.h>
27 /* Import the definition of RULE_T. */
28 # include "gram.h"
30 /* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */
31 # include "state.h"
34 /** Build the LALR(1) automaton.
36 Find which rules need lookahead in each state, and which lookahead
37 tokens they accept.
39 Also builds:
40 - #goto_map
41 - #from_state
42 - #to_state
43 - #goto_follows
45 void lalr (void);
47 /**
48 * Set #nLA and allocate all reduction lookahead sets. Normally invoked by
49 * #lalr.
51 void initialize_LA (void);
53 /**
54 * Build only:
55 * - #goto_map
56 * - #from_state
57 * - #to_state
58 * Normally invoked by #lalr.
60 void set_goto_map (void);
62 /**
63 * Update state numbers recorded in #goto_map, #from_state, and #to_state such
64 * that:
65 * - \c nstates_old is the old number of states.
66 * - Where \c i is the old state number, <tt>old_to_new[i]</tt> is either:
67 * - \c nstates_old if state \c i is removed because it is unreachable.
68 * Thus, remove all goto entries involving this state.
69 * - The new state number.
71 void lalr_update_state_numbers (state_number old_to_new[],
72 state_number nstates_old);
75 /** Release the information related to lookahead tokens.
77 Can be performed once the action tables are computed. */
78 void lalr_free (void);
80 typedef size_t goto_number;
81 # define GOTO_NUMBER_MAXIMUM ((goto_number) -1)
83 /** Index into #from_state and #to_state.
85 All the transitions that accept a particular variable are grouped
86 together in FROM_STATE and TO_STATE, with indexes from GOTO_MAP[I -
87 NTOKENS] to GOTO_MAP[I - NTOKENS + 1] - 1 (including both). */
88 extern goto_number *goto_map;
90 /** The size of #from_state and #to_state. */
91 extern goto_number ngotos;
93 /** State number which a transition leads from. */
94 extern state_number *from_state;
96 /** State number it leads to. */
97 extern state_number *to_state;
99 /** The number of the goto from state SRC labeled with nterm SYM. */
100 goto_number map_goto (state_number src, symbol_number sym);
102 /* goto_follows[i] is the set of tokens following goto i. */
103 extern bitsetv goto_follows;
105 #endif /* !LALR_H_ */