X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/d257636504fc23c24be818a34f55a226bb29b719..c0cac722f7e5d7498528a67a37477cdf9ed1745c:/src/conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index bcd79bab..24f27cc8 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -67,7 +67,7 @@ log_resolution (rule_t *rule, symbol_number_t token,
       switch (resolution)
 	{
 	case shift_resolution:
-	case left_resolution:
+	case right_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  _("\
     Conflict between rule %d and token %s resolved as shift"),
@@ -75,7 +75,7 @@ log_resolution (rule_t *rule, symbol_number_t token,
 			  symbols[token]->tag);
 	  break;
 	case reduce_resolution:
-	case right_resolution:
+	case left_resolution:
 	  obstack_fgrow2 (&solved_conflicts_obstack,
 			  _("\
     Conflict between rule %d and token %s resolved as reduce"),
@@ -139,7 +139,7 @@ log_resolution (rule_t *rule, symbol_number_t token,
 static void
 flush_shift (state_t *state, int token)
 {
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
   int i;
 
   bitset_reset (lookaheadset, token);
@@ -170,18 +170,21 @@ flush_reduce (bitset lookaheads, int token)
 | shift or reduce tables so that there is no longer a conflict.     |
 |                                                                   |
 | LOOKAHEAD is the number of the lookahead bitset to consider.      |
+|                                                                   |
+| ERRS can be used to store discovered explicit errors.             |
 `------------------------------------------------------------------*/
 
 static void
-resolve_sr_conflict (state_t *state, int lookahead)
+resolve_sr_conflict (state_t *state, int ruleno,
+		     symbol_t **errs)
 {
   symbol_number_t i;
+  reductions_t *reds = state->reductions;
   /* Find the rule to reduce by to get precedence of reduction.  */
-  rule_t *redrule = state->lookaheads_rule[lookahead];
+  rule_t *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;
-  bitset lookaheads = state->lookaheads[lookahead];
-  errs_t *errp = errs_new (ntokens + 1);
-  errp->num = 0;
+  bitset lookaheads = reds->lookaheads[ruleno];
+  int nerrs = 0;
 
   for (i = 0; i < ntokens; i++)
     if (bitset_test (lookaheads, i)
@@ -224,7 +227,7 @@ resolve_sr_conflict (state_t *state, int lookahead)
 	      flush_shift (state, i);
 	      flush_reduce (lookaheads, i);
 	      /* Record an explicit error for this token.  */
-	      errp->symbols[errp->num++] = i;
+	      errs[nerrs++] = symbols[i];
 	      break;
 
 	    case undef_assoc:
@@ -235,8 +238,7 @@ resolve_sr_conflict (state_t *state, int lookahead)
 
   /* Some tokens have been explicitly made errors.  Allocate a
      permanent errs structure for this state, to record them.  */
-  state->errs = errs_dup (errp);
-  free (errp);
+  state_errs_set (state, nerrs, errs);
 
   if (obstack_object_size (&solved_conflicts_obstack))
     {
@@ -246,49 +248,62 @@ resolve_sr_conflict (state_t *state, int lookahead)
 }
 
 
+/*-------------------------------------------------------------------.
+| Solve the S/R conflicts of STATE using the                         |
+| precedence/associativity, and flag it inconsistent if it still has |
+| conflicts.  ERRS can be used as storage to compute the list of     |
+| lookaheads on which this STATE raises a parse error (%nonassoc).   |
+`-------------------------------------------------------------------*/
+
 static void
-set_conflicts (state_t *state)
+set_conflicts (state_t *state, symbol_t **errs)
 {
   int i;
-  transitions_t *transitions;
+  transitions_t *transitions = state->transitions;
+  reductions_t *reds = state->reductions;
 
   if (state->consistent)
     return;
 
   bitset_zero (lookaheadset);
 
-  transitions = state->shifts;
-  for (i = 0; i < transitions->num && TRANSITION_IS_SHIFT (transitions, i); i++)
-    if (!TRANSITION_IS_DISABLED (transitions, i))
-      bitset_set (lookaheadset, TRANSITION_SYMBOL (transitions, i));
+  FOR_EACH_SHIFT (transitions, i)
+    bitset_set (lookaheadset, TRANSITION_SYMBOL (transitions, 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 < state->nlookaheads; ++i)
-    if (state->lookaheads_rule[i]->prec
-	&& state->lookaheads_rule[i]->prec->prec
-	&& !bitset_disjoint_p (state->lookaheads[i], lookaheadset))
+  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 (state, i);
+	resolve_sr_conflict (state, i, errs);
 	break;
       }
 
   /* Loop over all rules which require lookahead in this state.  Check
      for conflicts not resolved above.  */
-  for (i = 0; i < state->nlookaheads; ++i)
+  for (i = 0; i < reds->num; ++i)
     {
-      if (!bitset_disjoint_p (state->lookaheads[i], lookaheadset))
+      if (!bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
 	conflicts[state->number] = 1;
 
-      bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]);
+      bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
     }
 }
 
+
+/*----------------------------------------------------------------.
+| Solve all the S/R conflicts using the precedence/associativity, |
+| and flag as inconsistent the states that still have conflicts.  |
+`----------------------------------------------------------------*/
+
 void
 conflicts_solve (void)
 {
   state_number_t i;
+  /* List of lookaheads on which we explicitly raise a parse error.  */
+  symbol_t **errs = XMALLOC (symbol_t *, ntokens + 1);
 
   conflicts = XCALLOC (char, nstates);
   shiftset = bitset_create (ntokens, BITSET_FIXED);
@@ -296,7 +311,16 @@ conflicts_solve (void)
   obstack_init (&solved_conflicts_obstack);
 
   for (i = 0; i < nstates; i++)
-    set_conflicts (states[i]);
+    {
+      set_conflicts (states[i], errs);
+
+      /* For uniformity of the code, make sure all the states have a valid
+	 `errs' member.  */
+      if (!states[i]->errs)
+	states[i]->errs = errs_new (0, 0);
+    }
+
+  free (errs);
 }
 
 
@@ -309,7 +333,8 @@ count_sr_conflicts (state_t *state)
 {
   int i;
   int src_count = 0;
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
+  reductions_t *reds = state->reductions;
 
   if (!transitions)
     return 0;
@@ -317,12 +342,11 @@ count_sr_conflicts (state_t *state)
   bitset_zero (lookaheadset);
   bitset_zero (shiftset);
 
-  for (i = 0; i < transitions->num && TRANSITION_IS_SHIFT (transitions, i); i++)
-    if (!TRANSITION_IS_DISABLED (transitions, i))
-      bitset_set (shiftset, TRANSITION_SYMBOL (transitions, i));
+  FOR_EACH_SHIFT (transitions, i)
+    bitset_set (shiftset, TRANSITION_SYMBOL (transitions, i));
 
-  for (i = 0; i < state->nlookaheads; ++i)
-    bitset_or (lookaheadset, lookaheadset, state->lookaheads[i]);
+  for (i = 0; i < reds->num; ++i)
+    bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
 
   bitset_and (lookaheadset, lookaheadset, shiftset);
 
@@ -343,17 +367,15 @@ static int
 count_rr_conflicts (state_t *state, int one_per_token)
 {
   int i;
+  reductions_t *reds = state->reductions;
   int rrc_count = 0;
 
-  if (state->nlookaheads < 2)
-    return 0;
-
   for (i = 0; i < ntokens; i++)
     {
       int count = 0;
       int j;
-      for (j = 0; j < state->nlookaheads; ++j)
-	if (bitset_test (state->lookaheads[j], i))
+      for (j = 0; j < reds->num; ++j)
+	if (bitset_test (reds->lookaheads[j], i))
 	  count++;
 
       if (count >= 2)
@@ -363,6 +385,7 @@ count_rr_conflicts (state_t *state, int one_per_token)
   return rrc_count;
 }
 
+
 /*--------------------------------------------------------------.
 | Return a human readable string which reports shift/reduce and |
 | reduce/reduce conflict numbers (SRC_NUM, RRC_NUM).            |
@@ -394,14 +417,32 @@ conflict_report (int src_num, int rrc_num)
       cp += strlen (cp);
     }
 
-  *cp++ = '.';
-  *cp++ = '\n';
   *cp++ = '\0';
 
   return res;
 }
 
 
+/*----------------------------------------------------------------.
+| Same as above, but report the number of conflicts a` la POSIX.  |
+`----------------------------------------------------------------*/
+
+static void
+conflict_report_yacc (int src_num, int rrc_num)
+{
+  /* If invoked with `--yacc', use the output format specified by
+     POSIX.  */
+  fprintf (stderr, _("conflicts: "));
+  if (src_num > 0)
+    fprintf (stderr, _(" %d shift/reduce"), src_num);
+  if (src_num > 0 && rrc_num > 0)
+    fprintf (stderr, ",");
+  if (rrc_num > 0)
+    fprintf (stderr, _(" %d reduce/reduce"), rrc_num);
+  putc ('\n', stderr);
+}
+
+
 /*-----------------------------------------------------------.
 | Output the detailed description of states with conflicts.  |
 `-----------------------------------------------------------*/
@@ -412,13 +453,17 @@ conflicts_output (FILE *out)
   bool printed_sth = FALSE;
   state_number_t i;
   for (i = 0; i < nstates; i++)
-    if (conflicts[i])
-      {
-	fprintf (out, _("State %d contains "), i);
-	fputs (conflict_report (count_sr_conflicts (states[i]),
-				count_rr_conflicts (states[i], TRUE)), out);
-	printed_sth = TRUE;
-      }
+    {
+      state_t *s = states[i];
+      if (conflicts[i])
+	{
+	  fprintf (out, _("State %d contains "), i);
+	  fprintf (out, "%s.\n",
+		   conflict_report (count_sr_conflicts (s),
+				    count_rr_conflicts (s, TRUE)));
+	  printed_sth = TRUE;
+	}
+    }
   if (printed_sth)
     fputs ("\n\n", out);
 }
@@ -484,32 +529,15 @@ conflicts_print (void)
 
   /* Report the total number of conflicts on STDERR.  */
   if (yacc_flag)
-    {
-      /* If invoked with `--yacc', use the output format specified by
-	 POSIX.  */
-      fprintf (stderr, _("conflicts: "));
-      if (src_total > 0)
-	fprintf (stderr, _(" %d shift/reduce"), src_total);
-      if (src_total > 0 && rrc_total > 0)
-	fprintf (stderr, ",");
-      if (rrc_total > 0)
-	fprintf (stderr, _(" %d reduce/reduce"), rrc_total);
-      putc ('\n', stderr);
-    }
+    conflict_report_yacc (src_total, rrc_total);
   else
-    {
-      fprintf (stderr, _("%s contains "), infile);
-      fputs (conflict_report (src_total, rrc_total), stderr);
-    }
+    warn ("%s", conflict_report (src_total, rrc_total));
 
   if (expected_conflicts != -1 && !src_ok)
-    {
-      complain_message_count++;
-      fprintf (stderr, ngettext ("expected %d shift/reduce conflict\n",
-				 "expected %d shift/reduce conflicts\n",
-				 expected_conflicts),
-	       expected_conflicts);
-    }
+    complain (ngettext ("expected %d shift/reduce conflict",
+			"expected %d shift/reduce conflicts",
+			expected_conflicts),
+	      expected_conflicts);
 }