/* Compute lookahead criteria for Bison.
- Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 2000-2012 Free Software Foundation,
+ Inc.
This file is part of Bison, the GNU Compiler Compiler.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-/* Compute how to make the finite state machine deterministic; find
- which rules need lookahead in each state, and which lookahead
+/* Find which rules need lookahead in each state, and which lookahead
tokens they accept. */
#include <config.h>
#include "getargs.h"
#include "gram.h"
#include "lalr.h"
-#include "muscle_tab.h"
+#include "muscle-tab.h"
#include "nullable.h"
#include "reader.h"
#include "relation.h"
`----------------------------------------------------*/
static int
-state_lookahead_tokens_count (state *s, bool default_rule_only_for_accept)
+state_lookahead_tokens_count (state *s, bool default_reduction_only_for_accept)
{
int n_lookahead_tokens = 0;
reductions *rp = s->reductions;
/* We need a lookahead either to distinguish different reductions
(i.e., there are two or more), or to distinguish a reduction from a
shift. Otherwise, it is straightforward, and the state is
- `consistent'. However, for states that have any rules, treat only
- the accepting state as consistent (since there is never a lookahead
- token that makes sense there, and so no lookahead token should be
- read) if the user has otherwise disabled default rules. */
+ `consistent'. However, do not treat a state with any reductions as
+ consistent unless it is the accepting state (because there is never
+ a lookahead token that makes sense there, and so no lookahead token
+ should be read) if the user has otherwise disabled default
+ reductions. */
if (rp->num > 1
|| (rp->num == 1 && sp->num && TRANSITION_IS_SHIFT (sp, 0))
|| (rp->num == 1 && rp->rules[0]->number != 0
- && default_rule_only_for_accept))
+ && default_reduction_only_for_accept))
n_lookahead_tokens += rp->num;
else
s->consistent = 1;
{
state_number i;
bitsetv pLA;
- bool default_rule_only_for_accept;
+ bool default_reduction_only_for_accept;
{
- char *default_rules = muscle_percent_define_get ("lr.default_rules");
- default_rule_only_for_accept = 0 == strcmp (default_rules, "accepting");
- free (default_rules);
+ char *default_reductions =
+ muscle_percent_define_get ("lr.default-reductions");
+ default_reduction_only_for_accept =
+ 0 == strcmp (default_reductions, "accepting");
+ free (default_reductions);
}
/* Compute the total number of reductions requiring a lookahead. */
nLA = 0;
for (i = 0; i < nstates; i++)
nLA +=
- state_lookahead_tokens_count (states[i], default_rule_only_for_accept);
+ state_lookahead_tokens_count (states[i],
+ default_reduction_only_for_accept);
/* Avoid having to special case 0. */
if (!nLA)
nLA = 1;
for (i = 0; i < nstates; i++)
{
int count =
- state_lookahead_tokens_count (states[i], default_rule_only_for_accept);
+ state_lookahead_tokens_count (states[i],
+ default_reduction_only_for_accept);
if (count)
{
states[i]->reductions->lookahead_tokens = pLA;