| 1 | /* Subroutines for bison |
| 2 | Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of Bison, the GNU Compiler Compiler. |
| 5 | |
| 6 | Bison is free software; you can redistribute it and/or modify it |
| 7 | under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2, or (at your option) |
| 9 | any later version. |
| 10 | |
| 11 | Bison is distributed in the hope that it will be useful, but |
| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with Bison; see the file COPYING. If not, write to the Free |
| 18 | Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA |
| 19 | 02111-1307, USA. */ |
| 20 | |
| 21 | #ifndef CLOSURE_H_ |
| 22 | # define CLOSURE_H_ |
| 23 | |
| 24 | /* Allocates the itemset and ruleset vectors, and precomputes useful |
| 25 | data so that closure can be called. n is the number of elements to |
| 26 | allocate for itemset. */ |
| 27 | |
| 28 | void new_closure PARAMS ((int n)); |
| 29 | |
| 30 | |
| 31 | /* Given the kernel (aka core) of a state (a vector of item numbers |
| 32 | ITEMS, of length N), set up RULESET and ITEMSET to indicate what |
| 33 | rules could be run and which items could be accepted when those |
| 34 | items are the active ones. |
| 35 | |
| 36 | RULESET contains a bit for each rule. CLOSURE sets the bits for |
| 37 | all rules which could potentially describe the next input to be |
| 38 | read. |
| 39 | |
| 40 | ITEMSET is a vector of item numbers; NITEMSET is its size |
| 41 | (actually, points to just beyond the end of the part of it that is |
| 42 | significant). CLOSURE places there the indices of all items which |
| 43 | represent units of input that could arrive next. */ |
| 44 | |
| 45 | void closure PARAMS ((item_number_t *items, int n)); |
| 46 | |
| 47 | |
| 48 | /* Frees ITEMSET, RULESET and internal data. */ |
| 49 | |
| 50 | void free_closure PARAMS ((void)); |
| 51 | |
| 52 | extern item_number_t *itemset; |
| 53 | extern int nritemset; |
| 54 | |
| 55 | #endif /* !CLOSURE_H_ */ |