| | 1 | /* Compute lookahead criteria for bison, |
| | 2 | |
| | 3 | Copyright (C) 1984, 1986, 1989, 2000, 2002, 2004, 2006-2007, |
| | 4 | 2009-2010 Free 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 | #ifndef LALR_H_ |
| | 22 | # define LALR_H_ |
| | 23 | |
| | 24 | # include <bitset.h> |
| | 25 | # include <bitsetv.h> |
| | 26 | |
| | 27 | /* Import the definition of RULE_T. */ |
| | 28 | # include "gram.h" |
| | 29 | |
| | 30 | /* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */ |
| | 31 | # include "state.h" |
| | 32 | |
| | 33 | |
| | 34 | /** Build the LALR(1) automaton. |
| | 35 | |
| | 36 | Find which rules need lookahead in each state, and which lookahead |
| | 37 | tokens they accept. |
| | 38 | |
| | 39 | Also builds: |
| | 40 | - #goto_map |
| | 41 | - #from_state |
| | 42 | - #to_state |
| | 43 | - #goto_follows |
| | 44 | */ |
| | 45 | void lalr (void); |
| | 46 | |
| | 47 | /** |
| | 48 | * Set #nLA and allocate all reduction lookahead sets. Normally invoked by |
| | 49 | * #lalr. |
| | 50 | */ |
| | 51 | void initialize_LA (void); |
| | 52 | |
| | 53 | /** |
| | 54 | * Build only: |
| | 55 | * - #goto_map |
| | 56 | * - #from_state |
| | 57 | * - #to_state |
| | 58 | * Normally invoked by #lalr. |
| | 59 | */ |
| | 60 | void set_goto_map (void); |
| | 61 | |
| | 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. |
| | 70 | */ |
| | 71 | void lalr_update_state_numbers (state_number old_to_new[], |
| | 72 | state_number nstates_old); |
| | 73 | |
| | 74 | |
| | 75 | /** Release the information related to lookahead tokens. |
| | 76 | |
| | 77 | Can be performed once the action tables are computed. */ |
| | 78 | void lalr_free (void); |
| | 79 | |
| | 80 | typedef size_t goto_number; |
| | 81 | # define GOTO_NUMBER_MAXIMUM ((goto_number) -1) |
| | 82 | |
| | 83 | /** Index into #from_state and #to_state. |
| | 84 | |
| | 85 | All the transitions that accept a particular variable are grouped |
| | 86 | together and GOTO_MAP[I - NTOKENS] is the index in FROM_STATE and |
| | 87 | TO_STATE of the first of them. */ |
| | 88 | extern goto_number *goto_map; |
| | 89 | |
| | 90 | /** The size of #from_state and #to_state. */ |
| | 91 | extern goto_number ngotos; |
| | 92 | |
| | 93 | /** State number which a transition leads from. */ |
| | 94 | extern state_number *from_state; |
| | 95 | |
| | 96 | /** State number it leads to. */ |
| | 97 | extern state_number *to_state; |
| | 98 | |
| | 99 | /** Map a state/symbol pair into its numeric representation. */ |
| | 100 | goto_number map_goto (state_number s0, symbol_number sym); |
| | 101 | |
| | 102 | /* goto_follows[i] is the set of tokens following goto i. */ |
| | 103 | extern bitsetv goto_follows; |
| | 104 | |
| | 105 | |
| | 106 | #endif /* !LALR_H_ */ |
projects / bison.git / blame_incremental