-/* Compute look-ahead criteria for bison,
- Copyright (C) 1984, 1986, 1989, 2000, 2002 Free Software Foundation, Inc.
+/* Compute lookahead criteria for bison,
+
+ Copyright (C) 1984, 1986, 1989, 2000, 2002, 2004, 2006, 2007, 2009
+ Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
- Bison is free software; you can redistribute it and/or modify
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
- Bison is distributed in the hope that it will be useful,
+ This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with Bison; see the file COPYING. If not, write to
- the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef LALR_H_
# define LALR_H_
-# include "bitset.h"
-# include "bitsetv.h"
+# include <bitset.h>
+# include <bitsetv.h>
+
+/* Import the definition of RULE_T. */
+# include "gram.h"
/* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */
# include "state.h"
-/* Import the definition of RULE_T. */
-# include "gram.h"
-/* Compute how to make the finite state machine deterministic; find
- which rules need lookahead in each state, and which lookahead
- tokens they accept. */
+/** Build the LALR(1) automaton.
+ Compute how to make the finite state machine deterministic; find
+ which rules need lookahead in each state, and which lookahead
+ tokens they accept.
+
+ Also builds:
+ - #goto_map
+ - #from_state
+ - #to_state
+ - #goto_follows
+*/
void lalr (void);
-/* Release the information related to lookaheads. Can be performed
- once the action tables are computed. */
-
+/**
+ * Set #nLA and allocate all reduction lookahead sets. Normally invoked by
+ * #lalr.
+ */
+void initialize_LA (void);
+
+/**
+ * Build only:
+ * - #goto_map
+ * - #from_state
+ * - #to_state
+ * Normally invoked by #lalr.
+ */
+void set_goto_map (void);
+
+/**
+ * Update state numbers recorded in #goto_map, #from_state, and #to_state such
+ * that:
+ * - \c nstates_old is the old number of states.
+ * - Where \c i is the old state number, <tt>old_to_new[i]</tt> is either:
+ * - \c nstates_old if state \c i is removed because it is unreachable.
+ * Thus, remove all goto entries involving this state.
+ * - The new state number.
+ */
+void lalr_update_state_numbers (state_number old_to_new[],
+ state_number nstates_old);
+
+
+/** Release the information related to lookahead tokens.
+
+ Can be performed once the action tables are computed. */
void lalr_free (void);
+typedef size_t goto_number;
+# define GOTO_NUMBER_MAXIMUM ((goto_number) -1)
-/* lalr() builds these data structures. */
-
-/* GOTO_MAP, FROM_STATE and TO_STATE -- record each shift transition
- which accepts a variable (a nonterminal).
-
- FROM_STATE[T] -- state number which a transition leads from.
- TO_STATE[T] -- state number it leads to.
+/** Index into #from_state and #to_state.
All the transitions that accept a particular variable are grouped
together and GOTO_MAP[I - NTOKENS] is the index in FROM_STATE and
TO_STATE of the first of them. */
+extern goto_number *goto_map;
+
+/** The size of #from_state and #to_state. */
+extern goto_number ngotos;
+
+/** State number which a transition leads from. */
+extern state_number *from_state;
+
+/** State number it leads to. */
+extern state_number *to_state;
-typedef short goto_number_t;
-# define GOTO_NUMBER_MAX ((goto_number_t) SHRT_MAX)
+/** Map a state/symbol pair into its numeric representation. */
+goto_number map_goto (state_number s0, symbol_number sym);
-extern goto_number_t *goto_map;
-extern state_number_t *from_state;
-extern state_number_t *to_state;
+/* goto_follows[i] is the set of tokens following goto i. */
+extern bitsetv goto_follows;
#endif /* !LALR_H_ */
projects / bison.git / blobdiff