-/* 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, 2004, 2005
- Free Software Foundation, Inc.
+ Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
+ 2007, 2008 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 "print-xml.h"
#include "reader.h"
#include "state.h"
#include "symtab.h"
int expected_sr_conflicts = -1;
int expected_rr_conflicts = -1;
static char *conflicts;
-struct obstack solved_conflicts_obstack;
+static struct obstack solved_conflicts_obstack;
+static struct obstack solved_conflicts_xml_obstack;
static bitset shift_set;
-static bitset look_ahead_set;
+static bitset lookahead_set;
\f
case shift_resolution:
case right_resolution:
obstack_fgrow2 (&solved_conflicts_obstack,
- _("\
- Conflict between rule %d and token %s resolved as shift"),
+ _(" 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"),
+ _(" 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"),
+ _(" Conflict between rule %d and token %s"
+ " resolved as an error"),
r->number,
symbols[token]->tag);
break;
" (%%right %s)",
symbols[token]->tag);
break;
+
case nonassoc_resolution:
obstack_fgrow1 (&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_fgrow2 (&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_fgrow2 (&solved_conflicts_xml_obstack,
+ " <resolution rule=\"%d\" symbol=\"%s\""
+ " type=\"reduce\">",
+ r->number,
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case nonassoc_resolution:
+ obstack_fgrow2 (&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_fgrow2 (&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_fgrow2 (&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_fgrow1 (&solved_conflicts_xml_obstack,
+ "%%left %s",
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case right_resolution:
+ obstack_fgrow1 (&solved_conflicts_xml_obstack,
+ "%%right %s",
+ xml_escape (symbols[token]->tag));
+ break;
+
+ case nonassoc_resolution:
+ obstack_fgrow1 (&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 (look_ahead_set, token);
+ bitset_reset (lookahead_set, token);
for (i = 0; i < trans->num; i++)
if (!TRANSITION_IS_DISABLED (trans, i)
&& TRANSITION_SYMBOL (trans, i) == token)
/*--------------------------------------------------------------------.
-| Turn off the reduce recorded for the specified token for the |
-| specified look-ahead. 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 look_ahead_tokens, int token)
+flush_reduce (bitset lookahead_tokens, int token)
{
- bitset_reset (look_ahead_tokens, 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. |
| |
-| RULENO is the number of the look-ahead 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 look_ahead_tokens = reds->look_ahead_tokens[ruleno];
- int nerrs = 0;
+ bitset lookahead_tokens = reds->lookahead_tokens[ruleno];
for (i = 0; i < ntokens; i++)
- if (bitset_test (look_ahead_tokens, i)
- && bitset_test (look_ahead_set, i)
+ if (bitset_test (lookahead_tokens, i)
+ && bitset_test (lookahead_set, i)
&& symbols[i]->prec)
{
/* Shift-reduce conflict occurs for token number i
else if (symbols[i]->prec > redprec)
{
log_resolution (redrule, i, shift_resolution);
- flush_reduce (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
}
else
- /* Matching precedence levels.
- For left association, keep only the reduction.
- For right association, keep only the shift.
- For nonassociation, keep neither. */
+ /* 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 (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
break;
case left_assoc:
case non_assoc:
log_resolution (redrule, i, nonassoc_resolution);
flush_shift (s, i);
- flush_reduce (look_ahead_tokens, i);
+ flush_reduce (lookahead_tokens, i);
/* Record an explicit error for this token. */
- errors[nerrs++] = symbols[i];
+ errors[(*nerrs)++] = symbols[i];
break;
-
- case undef_assoc:
- abort ();
}
}
-
- 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))
- {
- 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 |
-| look-ahead tokens 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 (look_ahead_set);
+ bitset_zero (lookahead_set);
FOR_EACH_SHIFT (trans, i)
- bitset_set (look_ahead_set, TRANSITION_SYMBOL (trans, i));
+ bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, i));
- /* Loop over all rules which require look-ahead in this state. First
+ /* 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->look_ahead_tokens[i], look_ahead_set))
- resolve_sr_conflict (s, i, errors);
+ && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
+ resolve_sr_conflict (s, i, errors, &nerrs);
- /* Loop over all rules which require look-ahead in this state. Check
+ 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))
+ {
+ obstack_1grow (&solved_conflicts_obstack, '\0');
+ s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+ }
+ if (obstack_object_size (&solved_conflicts_xml_obstack))
+ {
+ obstack_1grow (&solved_conflicts_xml_obstack, '\0');
+ s->solved_conflicts_xml = obstack_finish (&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->look_ahead_tokens[i], look_ahead_set))
+ if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
conflicts[s->number] = 1;
-
- bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
}
}
conflicts_solve (void)
{
state_number i;
- /* List of look-ahead tokens on which we explicitly raise a syntax error. */
+ /* List of lookahead tokens on which we explicitly raise a syntax error. */
symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
conflicts = xcalloc (nstates, sizeof *conflicts);
shift_set = bitset_create (ntokens, BITSET_FIXED);
- look_ahead_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++)
{
}
+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 (look_ahead_set);
+ bitset_zero (lookahead_set);
bitset_zero (shift_set);
FOR_EACH_SHIFT (trans, i)
bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
for (i = 0; i < reds->num; ++i)
- bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+ bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
- bitset_and (look_ahead_set, look_ahead_set, shift_set);
+ bitset_and (lookahead_set, lookahead_set, shift_set);
- src_count = bitset_count (look_ahead_set);
+ src_count = bitset_count (lookahead_set);
return src_count;
}
int count = 0;
int j;
for (j = 0; j < reds->num; ++j)
- if (bitset_test (reds->look_ahead_tokens[j], i))
+ if (bitset_test (reds->lookahead_tokens[j], i))
count++;
if (count >= 2)
/*--------------------------------------------------------.
| 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 look-ahead as one |
+| reductions for the same state and lookahead as one |
| conflict. |
`--------------------------------------------------------*/
{
free (conflicts);
bitset_free (shift_set);
- bitset_free (look_ahead_set);
+ bitset_free (lookahead_set);
obstack_free (&solved_conflicts_obstack, NULL);
+ obstack_free (&solved_conflicts_xml_obstack, NULL);
}
projects / bison.git / blobdiff