named references: fix double free.

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 945d41f8e0e8fc8ac35a1deeb2ad7e769f779bbf..b357e2db23bf499d00c874870dd8922ac9e346b6 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,24 +1,22 @@
-/* Generate the nondeterministic finite state machine for Bison.
+/* Generate the LR(0) parser states for Bison.
 
-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2004, 2005, 2006
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 2000-2002, 2004-2007, 2009-2011 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., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 
 /* See comments in state.h for the data structures that represent it.
@@ -169,6 +167,10 @@ free_storage (void)
 | shifted.  For each symbol in the grammar, kernel_base[symbol]  |
 | points to a vector of item numbers activated if that symbol is |
 | shifted, and kernel_size[symbol] is their numbers.             |
+|                                                                |
+| itemset is sorted on item index in ritem, which is sorted on   |
+| rule number.  Compute each kernel_base[symbol] with the same   |
+| sort.                                                          |
 `---------------------------------------------------------------*/
 
 static void
@@ -183,8 +185,8 @@ new_itemsets (state *s)
 
   nshifts = 0;
 
-  for (i = 0; i < nritemset; ++i)
-    if (ritem[itemset[i]] >= 0)
+  for (i = 0; i < nitemset; ++i)
+    if (item_number_is_symbol_number (ritem[itemset[i]]))
       {
        symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
        if (!kernel_size[sym])
@@ -272,7 +274,7 @@ save_reductions (state *s)
   size_t i;
 
   /* Find and count the active items that represent ends of rules. */
-  for (i = 0; i < nritemset; ++i)
+  for (i = 0; i < nitemset; ++i)
     {
       item_number item = ritem[itemset[i]];
       if (item_number_is_rule_number (item))
@@ -327,8 +329,8 @@ set_states (void)
 
 
 /*-------------------------------------------------------------------.
-| Compute the nondeterministic finite state machine (see state.h for |
-| details) from the grammar.                                         |
+| Compute the LR(0) parser states (see state.h for details) from the |
+| grammar.                                                           |
 `-------------------------------------------------------------------*/
 
 void
@@ -351,10 +353,8 @@ generate_states (void)
        fprintf (stderr, "Processing state %d (reached by %s)\n",
                 s->number,
                 symbols[s->accessing_symbol]->tag);
-      /* Set up ruleset and itemset for the transitions out of this
-         state.  ruleset gets a 1 bit for each rule that could reduce
-         now.  itemset gets a vector of all the items that could be
-         accepted next.  */
+      /* Set up itemset for the transitions out of this state.  itemset gets a
+         vector of all the items that could be accepted next.  */
       closure (s->items, s->nitems);
       /* Record the reductions allowed out of this state.  */
       save_reductions (s);