1 /* Compute look-ahead criteria for bison, 2 3 Copyright (C) 1984, 1986, 1989, 2000, 2002, 2004 Free Software 4 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 LALR_H_ 24 # define LALR_H_ 25 26 # include <bitset.h> 27 # include <bitsetv.h> 28 29 /* Import the definition of RULE_T. */ 30 # include "gram.h" 31 32 /* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */ 33 # include "state.h" 34 35 /* Compute how to make the finite state machine deterministic; find 36 which rules need look-ahead in each state, and which look-ahead 37 tokens they accept. */ 38 39 void lalr (void); 40 41 /* Release the information related to look-ahead tokens. Can be performed 42 once the action tables are computed. */ 43 44 void lalr_free (void); 45 46 47 /* lalr() builds these data structures. */ 48 49 /* GOTO_MAP, FROM_STATE and TO_STATE -- record each shift transition 50 which accepts a variable (a nonterminal). 51 52 FROM_STATE[T] -- state number which a transition leads from. 53 TO_STATE[T] -- state number it leads to. 54 55 All the transitions that accept a particular variable are grouped 56 together and GOTO_MAP[I - NTOKENS] is the index in FROM_STATE and 57 TO_STATE of the first of them. */ 58 59 typedef size_t goto_number; 60 # define GOTO_NUMBER_MAXIMUM ((goto_number) -1) 61 62 extern goto_number *goto_map; 63 extern state_number *from_state; 64 extern state_number *to_state; 65 66 67 #endif /* !LALR_H_ */ 68