/* Print information on generated parser, for bison,
- Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2003, 2004, 2005
- Free Software Foundation, Inc.
+ Copyright (C) 1984, 1986, 1989, 2000-2005, 2007, 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
+ 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/>. */
#include <config.h>
#include "system.h"
#include <bitset.h>
-#include <quotearg.h>
#include "LR0.h"
#include "closure.h"
#include "getargs.h"
#include "gram.h"
#include "lalr.h"
+#include "muscle-tab.h"
#include "print.h"
#include "reader.h"
#include "reduce.h"
#include "state.h"
#include "symtab.h"
+#include "tables.h"
-static bitset shift_set;
-static bitset lookahead_set;
+static bitset no_reduce_set;
#if 0
static void
{
closure (sitems, snritems);
sitems = itemset;
- snritems = nritemset;
+ snritems = nitemset;
}
if (!snritems)
fprintf (out, " %s", symbols[*sp]->tag);
/* Display the lookahead tokens? */
- if (report_flag & report_lookahead_tokens)
+ if (report_flag & report_lookahead_tokens
+ && item_number_is_rule_number (*sp1))
state_rule_lookahead_tokens_print (s, &rules[r], out);
fputc ('\n', out);
}
-/*-------------------------------------------------------------.
-| Return the default rule of S if it has one, NULL otherwise. |
-`-------------------------------------------------------------*/
-
-static rule *
-state_default_rule (state *s)
-{
- reductions *reds = s->reductions;
- rule *default_rule = NULL;
- int cmax = 0;
- int i;
-
- /* No need for a lookahead. */
- if (s->consistent)
- return reds->rules[0];
-
- /* 1. Each reduction is possibly masked by the lookahead tokens on which
- we shift (S/R conflicts)... */
- bitset_zero (shift_set);
- {
- transitions *trans = s->transitions;
- FOR_EACH_SHIFT (trans, i)
- {
- /* If this state has a shift for the error token, don't use a
- default rule. */
- if (TRANSITION_IS_ERROR (trans, i))
- return NULL;
- bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
- }
- }
-
- /* 2. Each reduction is possibly masked by the lookahead tokens on which
- we raise an error (due to %nonassoc). */
- {
- errs *errp = s->errs;
- for (i = 0; i < errp->num; i++)
- if (errp->symbols[i])
- bitset_set (shift_set, errp->symbols[i]->number);
- }
-
- for (i = 0; i < reds->num; ++i)
- {
- int count = 0;
-
- /* How many non-masked lookahead tokens are there for this
- reduction? */
- bitset_andn (lookahead_set, reds->lookahead_tokens[i], shift_set);
- count = bitset_count (lookahead_set);
-
- if (count > cmax)
- {
- cmax = count;
- default_rule = reds->rules[i];
- }
-
- /* 3. And finally, each reduction is possibly masked by previous
- reductions (in R/R conflicts, we keep the first reductions).
- */
- bitset_or (shift_set, shift_set, reds->lookahead_tokens[i]);
- }
-
- return default_rule;
-}
-
-
/*-------------------------------------------------------------------------.
| Report a reduction of RULE on LOOKAHEAD_TOKEN (which can be `default'). |
| If not ENABLED, the rule is masked by a shift or a reduce (S/R and |
{
transitions *trans = s->transitions;
reductions *reds = s->reductions;
- rule *default_rule = NULL;
+ rule *default_reduction = NULL;
size_t width = 0;
int i, j;
+ bool default_reduction_only = true;
if (reds->num == 0)
return;
- default_rule = state_default_rule (s);
+ if (yydefact[s->number] != 0)
+ default_reduction = &rules[yydefact[s->number] - 1];
- bitset_zero (shift_set);
+ bitset_zero (no_reduce_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
+ bitset_set (no_reduce_set, TRANSITION_SYMBOL (trans, i));
+ for (i = 0; i < s->errs->num; ++i)
+ if (s->errs->symbols[i])
+ bitset_set (no_reduce_set, s->errs->symbols[i]->number);
/* Compute the width of the lookahead token column. */
- if (default_rule)
+ if (default_reduction)
width = strlen (_("$default"));
if (reds->lookahead_tokens)
for (i = 0; i < ntokens; i++)
{
- bool count = bitset_test (shift_set, i);
+ bool count = bitset_test (no_reduce_set, i);
for (j = 0; j < reds->num; ++j)
if (bitset_test (reds->lookahead_tokens[j], i))
{
if (! count)
{
- if (reds->rules[j] != default_rule)
+ if (reds->rules[j] != default_reduction)
max_length (&width, symbols[i]->tag);
count = true;
}
for (i = 0; i < ntokens; i++)
{
bool defaulted = false;
- bool count = bitset_test (shift_set, i);
+ bool count = bitset_test (no_reduce_set, i);
+ if (count)
+ default_reduction_only = false;
for (j = 0; j < reds->num; ++j)
if (bitset_test (reds->lookahead_tokens[j], i))
{
if (! count)
{
- if (reds->rules[j] != default_rule)
- print_reduction (out, width,
- symbols[i]->tag,
- reds->rules[j], true);
+ if (reds->rules[j] != default_reduction)
+ {
+ default_reduction_only = false;
+ print_reduction (out, width,
+ symbols[i]->tag,
+ reds->rules[j], true);
+ }
else
defaulted = true;
count = true;
}
else
{
+ default_reduction_only = false;
if (defaulted)
print_reduction (out, width,
symbols[i]->tag,
- default_rule, true);
+ default_reduction, true);
defaulted = false;
print_reduction (out, width,
symbols[i]->tag,
}
}
- if (default_rule)
- print_reduction (out, width,
- _("$default"), default_rule, true);
+ if (default_reduction)
+ {
+ char *default_reductions =
+ muscle_percent_define_get ("lr.default-reductions");
+ print_reduction (out, width, _("$default"), default_reduction, true);
+ aver (0 == strcmp (default_reductions, "most")
+ || (0 == strcmp (default_reductions, "consistent")
+ && default_reduction_only)
+ || (reds->num == 1 && reds->rules[0]->number == 0));
+ free (default_reductions);
+ }
}
buffer[0] = 0;
column = strlen (tag);
fputs (tag, out);
- END_TEST (50);
+ END_TEST (65);
sprintf (buffer, " (%d)", i);
for (r = 0; r < nrules; r++)
if (left_count > 0)
{
- END_TEST (50);
+ END_TEST (65);
sprintf (buffer + strlen (buffer), _(" on left:"));
for (r = 0; r < nrules; r++)
{
- END_TEST (65);
if (rules[r].lhs->number == i)
- sprintf (buffer + strlen (buffer), " %d", r);
+ {
+ END_TEST (65);
+ sprintf (buffer + strlen (buffer), " %d", r);
+ }
}
}
{
if (left_count > 0)
sprintf (buffer + strlen (buffer), ",");
- END_TEST (50);
+ END_TEST (65);
sprintf (buffer + strlen (buffer), _(" on right:"));
for (r = 0; r < nrules; r++)
{
reduce_output (out);
grammar_rules_partial_print (out,
- _("Rules never reduced"), rule_never_reduced_p);
+ _("Rules useless in parser due to conflicts"),
+ rule_useless_in_parser_p);
conflicts_output (out);
print_grammar (out);
if (report_flag & report_itemsets)
new_closure (nritems);
/* Storage for print_reductions. */
- shift_set = bitset_create (ntokens, BITSET_FIXED);
- lookahead_set = bitset_create (ntokens, BITSET_FIXED);
+ no_reduce_set = bitset_create (ntokens, BITSET_FIXED);
for (i = 0; i < nstates; i++)
print_state (out, states[i]);
- bitset_free (shift_set);
- bitset_free (lookahead_set);
+ bitset_free (no_reduce_set);
if (report_flag & report_itemsets)
free_closure ();
projects / bison.git / blobdiff