-/* Find and resolve or report look-ahead conflicts for bison,
+/* Find and resolve or report lookahead conflicts for bison,
- Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003
- Free Software Foundation, Inc.
+ Copyright (C) 1984, 1989, 1992, 2000-2012 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., 59 Temple Place - Suite 330, Boston, MA
- 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+#include <config.h>
#include "system.h"
#include <bitset.h>
#include "getargs.h"
#include "gram.h"
#include "lalr.h"
+#include "print-xml.h"
#include "reader.h"
#include "state.h"
#include "symtab.h"
/* -1 stands for not specified. */
-int expected_conflicts = -1;
-static char *conflicts = NULL;
-struct obstack solved_conflicts_obstack;
+int expected_sr_conflicts = -1;
+int expected_rr_conflicts = -1;
+static char *conflicts;
+static struct obstack solved_conflicts_obstack;
+static struct obstack solved_conflicts_xml_obstack;
-static bitset shiftset;
-static bitset lookaheadset;
+static bitset shift_set;
+static bitset lookahead_set;
\f
static inline void
log_resolution (rule *r, symbol_number token,
- enum conflict_resolution resolution)
+ enum conflict_resolution resolution)
{
if (report_flag & report_solved_conflicts)
{
/* The description of the resolution. */
switch (resolution)
- {
- case shift_resolution:
- case right_resolution:
- obstack_fgrow2 (&solved_conflicts_obstack,
- _("\
- Conflict between rule %d and token %s resolved as shift"),
- r->number,
- symbols[token]->tag);
- break;
- case reduce_resolution:
- case left_resolution:
- obstack_fgrow2 (&solved_conflicts_obstack,
- _("\
- Conflict between rule %d and token %s resolved as reduce"),
- r->number,
- symbols[token]->tag);
- break;
- case nonassoc_resolution:
- obstack_fgrow2 (&solved_conflicts_obstack,
- _("\
- Conflict between rule %d and token %s resolved as an error"),
- r->number,
- symbols[token]->tag);
- break;
- }
+ {
+ case shift_resolution:
+ case right_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ _(" Conflict between rule %d and token %s"
+ " resolved as shift"),
+ r->number,
+ symbols[token]->tag);
+ break;
+
+ case reduce_resolution:
+ case left_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ _(" Conflict between rule %d and token %s"
+ " resolved as reduce"),
+ r->number,
+ symbols[token]->tag);
+ break;
+
+ case nonassoc_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ _(" Conflict between rule %d and token %s"
+ " resolved as an error"),
+ r->number,
+ symbols[token]->tag);
+ break;
+ }
/* The reason. */
switch (resolution)
- {
- case shift_resolution:
- obstack_fgrow2 (&solved_conflicts_obstack,
- " (%s < %s)",
- r->prec->tag,
- symbols[token]->tag);
- break;
-
- case reduce_resolution:
- obstack_fgrow2 (&solved_conflicts_obstack,
- " (%s < %s)",
- symbols[token]->tag,
- r->prec->tag);
- break;
-
- case left_resolution:
- obstack_fgrow1 (&solved_conflicts_obstack,
- " (%%left %s)",
- symbols[token]->tag);
- break;
-
- case right_resolution:
- obstack_fgrow1 (&solved_conflicts_obstack,
- " (%%right %s)",
- symbols[token]->tag);
- break;
- case nonassoc_resolution:
- obstack_fgrow1 (&solved_conflicts_obstack,
- " (%%nonassoc %s)",
- symbols[token]->tag);
- break;
- }
+ {
+ case shift_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%s < %s)",
+ r->prec->tag,
+ symbols[token]->tag);
+ break;
+
+ case reduce_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%s < %s)",
+ symbols[token]->tag,
+ r->prec->tag);
+ break;
+
+ case left_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%%left %s)",
+ symbols[token]->tag);
+ break;
+
+ case right_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%%right %s)",
+ symbols[token]->tag);
+ break;
+
+ case nonassoc_resolution:
+ obstack_printf (&solved_conflicts_obstack,
+ " (%%nonassoc %s)",
+ symbols[token]->tag);
+ break;
+ }
+
obstack_sgrow (&solved_conflicts_obstack, ".\n");
}
+
+ /* XML report */
+ if (xml_flag)
+ {
+ /* The description of the resolution. */
+ switch (resolution)
+ {
+ case shift_resolution:
+ case right_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ " <resolution rule=\"%d\" symbol=\"%s\""
+ " type=\"shift\">",
+ r->number,
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case reduce_resolution:
+ case left_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ " <resolution rule=\"%d\" symbol=\"%s\""
+ " type=\"reduce\">",
+ r->number,
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case nonassoc_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ " <resolution rule=\"%d\" symbol=\"%s\""
+ " type=\"error\">",
+ r->number,
+ xml_escape (symbols[token]->tag));
+ break;
+ }
+
+ /* The reason. */
+ switch (resolution)
+ {
+ case shift_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ "%s < %s",
+ xml_escape_n (0, r->prec->tag),
+ xml_escape_n (1, symbols[token]->tag));
+ break;
+
+ case reduce_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ "%s < %s",
+ xml_escape_n (0, symbols[token]->tag),
+ xml_escape_n (1, r->prec->tag));
+ break;
+
+ case left_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ "%%left %s",
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case right_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ "%%right %s",
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case nonassoc_resolution:
+ obstack_printf (&solved_conflicts_xml_obstack,
+ "%%nonassoc %s",
+ xml_escape (symbols[token]->tag));
+ break;
+ }
+
+ obstack_sgrow (&solved_conflicts_xml_obstack, "</resolution>\n");
+ }
}
/*------------------------------------------------------------------.
| Turn off the shift recorded for the specified token in the |
| specified state. Used when we resolve a shift-reduce conflict in |
-| favor of the reduction. |
+| favor of the reduction or as an error (%nonassoc). |
`------------------------------------------------------------------*/
static void
transitions *trans = s->transitions;
int i;
- bitset_reset (lookaheadset, token);
+ bitset_reset (lookahead_set, token);
for (i = 0; i < trans->num; i++)
if (!TRANSITION_IS_DISABLED (trans, i)
- && TRANSITION_SYMBOL (trans, i) == token)
+ && TRANSITION_SYMBOL (trans, i) == token)
TRANSITION_DISABLE (trans, i);
}
-/*-------------------------------------------------------------------.
-| Turn off the reduce recorded for the specified token for the |
-| specified lookahead. Used when we resolve a shift-reduce conflict |
-| in favor of the shift. |
-`-------------------------------------------------------------------*/
+/*--------------------------------------------------------------------.
+| Turn off the reduce recorded for the specified token in the |
+| specified lookahead set. Used when we resolve a shift-reduce |
+| conflict in favor of the shift or as an error (%nonassoc). |
+`--------------------------------------------------------------------*/
static void
-flush_reduce (bitset lookaheads, int token)
+flush_reduce (bitset lookahead_tokens, int token)
{
- bitset_reset (lookaheads, token);
+ bitset_reset (lookahead_tokens, token);
}
| rule has a precedence. A conflict is resolved by modifying the |
| shift or reduce tables so that there is no longer a conflict. |
| |
-| LOOKAHEAD is the number of the lookahead bitset to consider. |
+| RULENO is the number of the lookahead bitset to consider. |
| |
-| ERRORS can be used to store discovered explicit errors. |
+| ERRORS and NERRS can be used to store discovered explicit |
+| errors. |
`------------------------------------------------------------------*/
static void
-resolve_sr_conflict (state *s, int ruleno, symbol **errors)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs)
{
symbol_number i;
reductions *reds = s->reductions;
/* Find the rule to reduce by to get precedence of reduction. */
rule *redrule = reds->rules[ruleno];
int redprec = redrule->prec->prec;
- bitset lookaheads = reds->lookaheads[ruleno];
- int nerrs = 0;
+ bitset lookahead_tokens = reds->lookahead_tokens[ruleno];
for (i = 0; i < ntokens; i++)
- if (bitset_test (lookaheads, i)
- && bitset_test (lookaheadset, i)
- && symbols[i]->prec)
+ if (bitset_test (lookahead_tokens, i)
+ && bitset_test (lookahead_set, i)
+ && symbols[i]->prec)
{
- /* Shift-reduce conflict occurs for token number i
- and it has a precedence.
- The precedence of shifting is that of token i. */
- if (symbols[i]->prec < redprec)
- {
- log_resolution (redrule, i, reduce_resolution);
- flush_shift (s, i);
- }
- else if (symbols[i]->prec > redprec)
- {
- log_resolution (redrule, i, shift_resolution);
- flush_reduce (lookaheads, i);
- }
- else
- /* Matching precedence levels.
- For left association, keep only the reduction.
- For right association, keep only the shift.
- For nonassociation, keep neither. */
-
- switch (symbols[i]->assoc)
- {
- case right_assoc:
- log_resolution (redrule, i, right_resolution);
- flush_reduce (lookaheads, i);
- break;
-
- case left_assoc:
- log_resolution (redrule, i, left_resolution);
- flush_shift (s, i);
- break;
-
- case non_assoc:
- log_resolution (redrule, i, nonassoc_resolution);
- flush_shift (s, i);
- flush_reduce (lookaheads, i);
- /* Record an explicit error for this token. */
- errors[nerrs++] = symbols[i];
- break;
-
- case undef_assoc:
- abort ();
- }
+ /* Shift-reduce conflict occurs for token number i
+ and it has a precedence.
+ The precedence of shifting is that of token i. */
+ if (symbols[i]->prec < redprec)
+ {
+ log_resolution (redrule, i, reduce_resolution);
+ flush_shift (s, i);
+ }
+ else if (symbols[i]->prec > redprec)
+ {
+ log_resolution (redrule, i, shift_resolution);
+ flush_reduce (lookahead_tokens, i);
+ }
+ else
+ /* Matching precedence levels.
+ For non-defined associativity, keep both: unexpected
+ associativity conflict.
+ For left associativity, keep only the reduction.
+ For right associativity, keep only the shift.
+ For nonassociativity, keep neither. */
+
+ switch (symbols[i]->assoc)
+ {
+ case undef_assoc:
+ abort ();
+
+ case precedence_assoc:
+ break;
+
+ case right_assoc:
+ log_resolution (redrule, i, right_resolution);
+ flush_reduce (lookahead_tokens, i);
+ break;
+
+ case left_assoc:
+ log_resolution (redrule, i, left_resolution);
+ flush_shift (s, i);
+ break;
+
+ case non_assoc:
+ log_resolution (redrule, i, nonassoc_resolution);
+ flush_shift (s, i);
+ flush_reduce (lookahead_tokens, i);
+ /* Record an explicit error for this token. */
+ errors[(*nerrs)++] = symbols[i];
+ break;
+ }
}
-
- /* Some tokens have been explicitly made errors. Allocate a
- permanent errs structure for this state, to record them. */
- state_errs_set (s, nerrs, errors);
-
- if (obstack_object_size (&solved_conflicts_obstack))
- {
- obstack_1grow (&solved_conflicts_obstack, '\0');
- s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
- }
}
| Solve the S/R conflicts of state S using the |
| precedence/associativity, and flag it inconsistent if it still has |
| conflicts. ERRORS can be used as storage to compute the list of |
-| lookaheads on which S raises a syntax error (%nonassoc). |
+| lookahead tokens on which S raises a syntax error (%nonassoc). |
`-------------------------------------------------------------------*/
static void
int i;
transitions *trans = s->transitions;
reductions *reds = s->reductions;
+ int nerrs = 0;
if (s->consistent)
return;
- bitset_zero (lookaheadset);
+ bitset_zero (lookahead_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (lookaheadset, TRANSITION_SYMBOL (trans, i));
+ bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, i));
/* Loop over all rules which require lookahead in this state. First
check for shift-reduce conflict, and try to resolve using
precedence. */
for (i = 0; i < reds->num; ++i)
if (reds->rules[i]->prec && reds->rules[i]->prec->prec
- && !bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
- {
- resolve_sr_conflict (s, i, errors);
- break;
- }
+ && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
+ resolve_sr_conflict (s, i, errors, &nerrs);
+
+ if (nerrs)
+ {
+ /* Some tokens have been explicitly made errors. Allocate a
+ permanent errs structure for this state, to record them. */
+ state_errs_set (s, nerrs, errors);
+ }
+ if (obstack_object_size (&solved_conflicts_obstack))
+ s->solved_conflicts = obstack_finish0 (&solved_conflicts_obstack);
+ if (obstack_object_size (&solved_conflicts_xml_obstack))
+ s->solved_conflicts_xml = obstack_finish0 (&solved_conflicts_xml_obstack);
/* Loop over all rules which require lookahead in this state. Check
for conflicts not resolved above. */
for (i = 0; i < reds->num; ++i)
{
- if (!bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
- conflicts[s->number] = 1;
-
- bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
+ if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
+ conflicts[s->number] = 1;
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
}
}
conflicts_solve (void)
{
state_number i;
- /* List of lookaheads on which we explicitly raise a syntax error. */
- symbol **errors = MALLOC (errors, ntokens + 1);
+ /* List of lookahead tokens on which we explicitly raise a syntax error. */
+ symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
- CALLOC (conflicts, nstates);
- shiftset = bitset_create (ntokens, BITSET_FIXED);
- lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+ conflicts = xcalloc (nstates, sizeof *conflicts);
+ shift_set = bitset_create (ntokens, BITSET_FIXED);
+ lookahead_set = bitset_create (ntokens, BITSET_FIXED);
obstack_init (&solved_conflicts_obstack);
+ obstack_init (&solved_conflicts_xml_obstack);
for (i = 0; i < nstates; i++)
{
set_conflicts (states[i], errors);
/* For uniformity of the code, make sure all the states have a valid
- `errs' member. */
+ `errs' member. */
if (!states[i]->errs)
- states[i]->errs = errs_new (0, 0);
+ states[i]->errs = errs_new (0, 0);
}
free (errors);
}
+void
+conflicts_update_state_numbers (state_number old_to_new[],
+ state_number nstates_old)
+{
+ state_number i;
+ for (i = 0; i < nstates_old; ++i)
+ if (old_to_new[i] != nstates_old)
+ conflicts[old_to_new[i]] = conflicts[i];
+}
+
+
/*---------------------------------------------.
| Count the number of shift/reduce conflicts. |
`---------------------------------------------*/
if (!trans)
return 0;
- bitset_zero (lookaheadset);
- bitset_zero (shiftset);
+ bitset_zero (lookahead_set);
+ bitset_zero (shift_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (shiftset, TRANSITION_SYMBOL (trans, i));
+ bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
for (i = 0; i < reds->num; ++i)
- bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
- bitset_and (lookaheadset, lookaheadset, shiftset);
+ bitset_and (lookahead_set, lookahead_set, shift_set);
- src_count = bitset_count (lookaheadset);
+ src_count = bitset_count (lookahead_set);
return src_count;
}
+`----------------------------------------------------------------*/
static int
-count_rr_conflicts (state *s, int one_per_token)
+count_rr_conflicts (state *s, bool one_per_token)
{
int i;
reductions *reds = s->reductions;
int count = 0;
int j;
for (j = 0; j < reds->num; ++j)
- if (bitset_test (reds->lookaheads[j], i))
- count++;
+ if (bitset_test (reds->lookahead_tokens[j], i))
+ count++;
if (count >= 2)
- rrc_count += one_per_token ? 1 : count-1;
+ rrc_count += one_per_token ? 1 : count-1;
}
return rrc_count;
{
if (src_num && rrc_num)
fprintf (out, _("conflicts: %d shift/reduce, %d reduce/reduce\n"),
- src_num, rrc_num);
+ src_num, rrc_num);
else if (src_num)
fprintf (out, _("conflicts: %d shift/reduce\n"), src_num);
else if (rrc_num)
{
state *s = states[i];
if (conflicts[i])
- {
- fprintf (out, _("State %d "), i);
- conflict_report (out, count_sr_conflicts (s),
- count_rr_conflicts (s, true));
- printed_sth = true;
- }
+ {
+ fprintf (out, _("State %d "), i);
+ conflict_report (out, count_sr_conflicts (s),
+ count_rr_conflicts (s, true));
+ printed_sth = true;
+ }
}
if (printed_sth)
fputs ("\n\n", out);
| Total the number of S/R and R/R conflicts. Unlike the |
| code in conflicts_output, however, count EACH pair of |
| reductions for the same state and lookahead as one |
-| conflict. |
+| conflict. |
`--------------------------------------------------------*/
int
for (i = 0; i < nstates; i++)
if (conflicts[i])
{
- count += count_sr_conflicts (states[i]);
- count += count_rr_conflicts (states[i], false);
+ count += count_sr_conflicts (states[i]);
+ count += count_rr_conflicts (states[i], false);
}
return count;
}
/* Is the number of SR conflicts OK? Either EXPECTED_CONFLICTS is
not set, and then we want 0 SR, or else it is specified, in which
case we want equality. */
- int src_ok = 0;
+ bool src_ok;
+ bool rrc_ok;
int src_total = 0;
int rrc_total = 0;
+ int src_expected;
+ int rrc_expected;
/* Conflicts by state. */
{
for (i = 0; i < nstates; i++)
if (conflicts[i])
- {
- src_total += count_sr_conflicts (states[i]);
- rrc_total += count_rr_conflicts (states[i], true);
- }
+ {
+ src_total += count_sr_conflicts (states[i]);
+ rrc_total += count_rr_conflicts (states[i], true);
+ }
}
- src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
+ if (! glr_parser && expected_rr_conflicts != -1)
+ {
+ complain (Wother, _("%%expect-rr applies only to GLR parsers"));
+ expected_rr_conflicts = -1;
+ }
+
+ src_expected = expected_sr_conflicts == -1 ? 0 : expected_sr_conflicts;
+ rrc_expected = expected_rr_conflicts == -1 ? 0 : expected_rr_conflicts;
+ src_ok = src_total == src_expected;
+ rrc_ok = rrc_total == rrc_expected;
- /* If there are no RR conflicts, and as many SR conflicts as
+ /* If there are as many RR conflicts and SR conflicts as
expected, then there is nothing to report. */
- if (!rrc_total && src_ok)
+ if (rrc_ok & src_ok)
return;
/* Report the total number of conflicts on STDERR. */
- if (! yacc_flag)
- fprintf (stderr, "%s: ", current_file);
- conflict_report (stderr, src_total, rrc_total);
+ if (expected_sr_conflicts == -1 && expected_rr_conflicts == -1)
+ {
+ if (!(warnings_flag & Wconflicts_sr))
+ src_total = 0;
+ if (!(warnings_flag & Wconflicts_rr))
+ rrc_total = 0;
+ }
+ if (src_total | rrc_total)
+ {
+ if (expected_sr_conflicts == -1 && expected_rr_conflicts == -1)
+ set_warning_issued ();
+ if (! yacc_flag)
+ fprintf (stderr, "%s: ", current_file);
+ conflict_report (stderr, src_total, rrc_total);
+ }
- if (expected_conflicts != -1)
+ if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1)
{
if (! src_ok)
- warn (ngettext ("expected %d shift/reduce conflict",
- "expected %d shift/reduce conflicts",
- expected_conflicts),
- expected_conflicts);
- if (rrc_total)
- warn (_("expected 0 reduce/reduce conflicts"));
+ complain (complaint, ngettext ("expected %d shift/reduce conflict",
+ "expected %d shift/reduce conflicts",
+ src_expected),
+ src_expected);
+ if (! rrc_ok)
+ complain (complaint, ngettext ("expected %d reduce/reduce conflict",
+ "expected %d reduce/reduce conflicts",
+ rrc_expected),
+ rrc_expected);
}
}
void
conflicts_free (void)
{
- XFREE (conflicts);
- bitset_free (shiftset);
- bitset_free (lookaheadset);
+ free (conflicts);
+ bitset_free (shift_set);
+ bitset_free (lookahead_set);
obstack_free (&solved_conflicts_obstack, NULL);
+ obstack_free (&solved_conflicts_xml_obstack, NULL);
}
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