version 3.0

[bison.git] / src / lalr.h

diff --git a/src/lalr.h b/src/lalr.h
index ca18022d067ad7583c635c628528ffcf667019a8..f48331574705c3acaa22908028ca74406060b3ec 100644 (file)
--- a/src/lalr.h
+++ b/src/lalr.h
@@ -1,65 +1,106 @@
-/* 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,
+   2009-2013 Free Software Foundation, Inc.

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    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
    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
    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_
 
 
 #ifndef LALR_H_
 # define LALR_H_
 

-# include "bitset.h"
-# include "bitsetv.h"
-
-/* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */
-# include "state.h"
+# include <bitset.h>
+# include <bitsetv.h>

 
 /* Import the definition of RULE_T. */
 # include "gram.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.  */
+/* Import the definition of CORE, TRANSITIONS and REDUCTIONS. */
+# include "state.h"

 
 

-void lalr (void);

 
 

-/* Release the information related to lookaheads.  Can be performed
-   once the action tables are computed.  */
+/** Build the LALR(1) automaton.

 
 

-void lalr_free (void);
+   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);

 
 

-/* lalr() builds these data structures. */
+/**
+ * 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);

 
 

-/* GOTO_MAP, FROM_STATE and TO_STATE -- record each shift transition
-   which accepts a variable (a nonterminal).
+typedef size_t goto_number;
+# define GOTO_NUMBER_MAXIMUM ((goto_number) -1)

 
 

-   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.  */
 
    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_ */
 
 
 #endif /* !LALR_H_ */