/* Output the generated parsing program for Bison.
- Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004,
- 2005 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 1992, 2000-2006, 2009-2012 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 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.
+ 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 3 of the License, or
+ (at your option) any later version.
- Bison 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.
+ 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/>. */
#include <config.h>
#include "system.h"
#include "getargs.h"
#include "gram.h"
#include "lalr.h"
+#include "muscle-tab.h"
#include "reader.h"
#include "symtab.h"
#include "tables.h"
base_number *table;
base_number *check;
/* The value used in TABLE to denote explicit syntax errors
- (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MININUM,
+ (%nonassoc), a negative infinite. First defaults to ACTION_NUMBER_MINIMUM,
but in order to keep small tables, renumbered as TABLE_ERROR, which
is the smallest (non error) value minus 1. */
base_number table_ninf = 0;
/* Find all reductions for token J, and record all that do not
match ACTROW[J]. */
for (i = 0; i < reds->num; i += 1)
- if (bitset_test (reds->look_ahead_tokens[i], j)
+ if (bitset_test (reds->lookahead_tokens[i], j)
&& (actrow[j]
!= rule_number_as_item_number (reds->rules[i]->number)))
{
- if (conflict_list_free <= 0)
- abort ();
+ aver (0 < conflict_list_free);
conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1;
conflict_list_cnt += 1;
conflict_list_free -= 1;
}
/* Leave a 0 at the end. */
- if (conflict_list_free <= 0)
- abort ();
+ aver (0 < conflict_list_free);
conflict_list[conflict_list_cnt] = 0;
conflict_list_cnt += 1;
conflict_list_free -= 1;
/*------------------------------------------------------------------.
| Decide what to do for each type of token if seen as the |
-| look-ahead in specified state. The value returned is used as the |
+| lookahead in specified state. The value returned is used as the |
| default action (yydefact) for the state. In addition, ACTROW is |
| filled with what to do for each kind of token, index by symbol |
| number, with zero meaning do the default action. The value |
| situation is an error. The parser recognizes this value |
| specially. |
| |
-| This is where conflicts are resolved. The loop over look-ahead |
+| This is where conflicts are resolved. The loop over lookahead |
| rules considered lower-numbered rules last, and the last rule |
| considered that likes a token gets to handle it. |
| |
action_row (state *s)
{
int i;
- rule *default_rule = NULL;
+ rule *default_reduction = NULL;
reductions *reds = s->reductions;
transitions *trans = s->transitions;
errs *errp = s->errs;
for (i = 0; i < ntokens; i++)
actrow[i] = conflrow[i] = 0;
- if (reds->look_ahead_tokens)
+ if (reds->lookahead_tokens)
{
int j;
bitset_iterator biter;
/* loop over all the rules available here which require
- look-ahead (in reverse order to give precedence to the first
+ lookahead (in reverse order to give precedence to the first
rule) */
for (i = reds->num - 1; i >= 0; --i)
/* and find each token which the rule finds acceptable
to come next */
- BITSET_FOR_EACH (biter, reds->look_ahead_tokens[i], j, 0)
+ BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0)
{
/* and record this rule as the rule to use if that
token follows. */
actrow[sym->number] = ACTION_NUMBER_MINIMUM;
}
+ /* Turn off default reductions where requested by the user. See
+ state_lookahead_tokens_count in lalr.c to understand when states are
+ labeled as consistent. */
+ {
+ char *default_reductions =
+ muscle_percent_define_get ("lr.default-reductions");
+ if (0 != strcmp (default_reductions, "most") && !s->consistent)
+ nodefault = true;
+ free (default_reductions);
+ }
+
/* Now find the most common reduction and make it the default action
for this state. */
if (reds->num >= 1 && !nodefault)
{
if (s->consistent)
- default_rule = reds->rules[0];
+ default_reduction = reds->rules[0];
else
{
int max = 0;
if (count > max)
{
max = count;
- default_rule = r;
+ default_reduction = r;
}
}
{
int j;
for (j = 0; j < ntokens; j++)
- if (actrow[j] == rule_number_as_item_number (default_rule->number)
+ if (actrow[j]
+ == rule_number_as_item_number (default_reduction->number)
&& ! (nondeterministic_parser && conflrow[j]))
actrow[j] = 0;
}
}
}
- /* If have no default rule, the default is an error.
+ /* If have no default reduction, the default is an error.
So replace any action which says "error" with "use default". */
- if (!default_rule)
+ if (!default_reduction)
for (i = 0; i < ntokens; i++)
if (actrow[i] == ACTION_NUMBER_MINIMUM)
actrow[i] = 0;
if (conflicted)
conflict_row (s);
- return default_rule;
+ return default_reduction;
}
/*------------------------------------------------------------------.
| Figure out the actions for the specified state, indexed by |
-| look-ahead token type. |
+| lookahead token type. |
| |
| The YYDEFACT table is output now. The detailed info is saved for |
| putting into YYTABLE later. |
for (i = 0; i < nstates; ++i)
{
- rule *default_rule = action_row (states[i]);
- yydefact[i] = default_rule ? default_rule->number + 1 : 0;
+ rule *default_reduction = action_row (states[i]);
+ yydefact[i] = default_reduction ? default_reduction->number + 1 : 0;
save_row (i);
/* Now that the parser was computed, we can find which rules are
base_number *to = tos[i];
unsigned int *conflict_to = conflict_tos[i];
- if (!t)
- abort ();
+ aver (t != 0);
for (j = lowzero - from[0]; ; j++)
{
int k;
bool ok = true;
- if (table_size <= j)
- abort ();
+ aver (j < table_size);
for (k = 0; ok && k < t; k++)
{
if (loc > high)
high = loc;
- if (! (BASE_MINIMUM <= j && j <= BASE_MAXIMUM))
- abort ();
+ aver (BASE_MINIMUM <= j && j <= BASE_MAXIMUM);
return j;
}
}
projects / bison.git / blobdiff