/* Compute lookahead criteria for Bison.
Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006 Free Software Foundation, Inc.
+ 2006, 2007 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/>. */
/* Compute how to make the finite state machine deterministic; find
while (!done)
{
done = true;
- /* Each rhs ends in an item number, and there is a
+ /* Each rhs ends in a rule number, and there is a
sentinel before the first rhs, so it is safe to
decrement RP here. */
rp--;
static int
state_lookahead_tokens_count (state *s)
{
- int k;
int n_lookahead_tokens = 0;
reductions *rp = s->reductions;
transitions *sp = s->transitions;
/* 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'. */
+ and the state is `consistent'. There is no need to check that
+ transition 0 hasn't been disabled before checking if it is a
+ shift since transitions are only disabled during conflict
+ resolution, and that hasn't happened yet. */
+ aver (sp->num == 0 || !TRANSITION_IS_DISABLED (sp, 0));
if (rp->num > 1
- || (rp->num == 1 && sp->num &&
- !TRANSITION_IS_DISABLED (sp, 0) && TRANSITION_IS_SHIFT (sp, 0)))
+ || (rp->num == 1 && sp->num && TRANSITION_IS_SHIFT (sp, 0)))
n_lookahead_tokens += rp->num;
else
s->consistent = 1;
- for (k = 0; k < sp->num; k++)
- if (!TRANSITION_IS_DISABLED (sp, k) && TRANSITION_IS_ERROR (sp, k))
- {
- s->consistent = 0;
- break;
- }
-
return n_lookahead_tokens;
}
goto_number ngotos_reachable = 0;
symbol_number nonterminal = 0;
aver (nsyms == nvars + ntokens);
- for (goto_number i = 0; i < ngotos; ++i)
- {
- while (i == goto_map[nonterminal])
- goto_map[nonterminal++] = ngotos_reachable;
- /* If old_to_new[from_state[i]] = nstates_old, remove this goto
- entry. */
- if (old_to_new[from_state[i]] != nstates_old)
- {
- /* from_state[i] is not removed, so it and thus to_state[i] are
- reachable, so to_state[i] != nstates_old. */
- aver (old_to_new[to_state[i]] != nstates_old);
- from_state[ngotos_reachable] = old_to_new[from_state[i]];
- to_state[ngotos_reachable] = old_to_new[to_state[i]];
- ++ngotos_reachable;
- }
- }
+ {
+ goto_number i;
+ for (i = 0; i < ngotos; ++i)
+ {
+ while (i == goto_map[nonterminal])
+ goto_map[nonterminal++] = ngotos_reachable;
+ /* If old_to_new[from_state[i]] = nstates_old, remove this goto
+ entry. */
+ if (old_to_new[from_state[i]] != nstates_old)
+ {
+ /* from_state[i] is not removed, so it and thus to_state[i] are
+ reachable, so to_state[i] != nstates_old. */
+ aver (old_to_new[to_state[i]] != nstates_old);
+ from_state[ngotos_reachable] = old_to_new[from_state[i]];
+ to_state[ngotos_reachable] = old_to_new[to_state[i]];
+ ++ngotos_reachable;
+ }
+ }
+ }
while (nonterminal <= nvars)
{
aver (ngotos == goto_map[nonterminal]);