X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/342b8b6e2156e923797745af2da2596e3086ccd5..66ef8b9d658b091bb3deb7a25067d6b2aa7566dc:/src/conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index 626db934..44546e1c 100644
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,5 +1,7 @@
 /* Find and resolve or report look-ahead conflicts for bison,
-   Copyright 1984, 1989, 1992, 2000, 2001 Free Software Foundation, Inc.
+
+   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003
+   Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -19,35 +21,115 @@
    02111-1307, USA.  */
 
 #include "system.h"
-#include "getargs.h"
+
+#include <bitset.h>
+
+#include "LR0.h"
+#include "complain.h"
+#include "conflicts.h"
 #include "files.h"
+#include "getargs.h"
 #include "gram.h"
-#include "state.h"
 #include "lalr.h"
-#include "conflicts.h"
 #include "reader.h"
-#include "LR0.h"
+#include "state.h"
+#include "symtab.h"
 
-int any_conflicts = 0;
-errs **err_table = NULL;
-int expected_conflicts;
+/* -1 stands for not specified. */
+int expected_conflicts = -1;
 static char *conflicts = NULL;
+struct obstack solved_conflicts_obstack;
+
+static bitset shiftset;
+static bitset lookaheadset;
 
-static unsigned *shiftset = NULL;
-static unsigned *lookaheadset = NULL;
-static int src_total;
-static int rrc_total;
-static int src_count;
-static int rrc_count;
 
 
+enum conflict_resolution
+  {
+    shift_resolution,
+    reduce_resolution,
+    left_resolution,
+    right_resolution,
+    nonassoc_resolution
+  };
+
+
+/*----------------------------------------------------------------.
+| Explain how an SR conflict between TOKEN and RULE was resolved: |
+| RESOLUTION.                                                     |
+`----------------------------------------------------------------*/
+
 static inline void
-log_resolution (int state, int LAno, int token, char *resolution)
+log_resolution (rule *r, symbol_number token,
+		enum conflict_resolution resolution)
 {
-  obstack_fgrow4 (&output_obstack,
-		  _("\
-Conflict in state %d between rule %d and token %s resolved as %s.\n"),
-		  state, LAruleno[LAno], tags[token], 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;
+	}
+
+      /* 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;
+	}
+      obstack_sgrow (&solved_conflicts_obstack, ".\n");
+    }
 }
 
 
@@ -58,23 +140,29 @@ Conflict in state %d between rule %d and token %s resolved as %s.\n"),
 `------------------------------------------------------------------*/
 
 static void
-flush_shift (int state, int token)
+flush_shift (state *s, int token)
 {
-  shifts *shiftp;
-  int k, i;
+  transitions *trans = s->transitions;
+  int i;
 
-  shiftp = shift_table[state];
+  bitset_reset (lookaheadset, token);
+  for (i = 0; i < trans->num; i++)
+    if (!TRANSITION_IS_DISABLED (trans, i)
+	&& TRANSITION_SYMBOL (trans, i) == token)
+      TRANSITION_DISABLE (trans, i);
+}
 
-  if (shiftp)
-    {
-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
-	{
-	  if (shiftp->shifts[i]
-	      && token == accessing_symbol[shiftp->shifts[i]])
-	    (shiftp->shifts[i]) = 0;
-	}
-    }
+
+/*-------------------------------------------------------------------.
+| 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.                                             |
+`-------------------------------------------------------------------*/
+
+static void
+flush_reduce (bitset lookaheads, int token)
+{
+  bitset_reset (lookaheads, token);
 }
 
 
@@ -83,200 +171,157 @@ flush_shift (int state, int token)
 | precedence declarations.  It has already been checked that the    |
 | 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.      |
+|                                                                   |
+| ERRORS can be used to store discovered explicit errors.           |
 `------------------------------------------------------------------*/
 
 static void
-resolve_sr_conflict (int state, int lookaheadnum)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 {
-  int i;
-  int mask;
-  unsigned *fp1;
-  unsigned *fp2;
-  int redprec;
-  errs *errp = (errs *) xcalloc (sizeof (errs) + ntokens * sizeof (short), 1);
-  short *errtokens = errp->errs;
-
-  /* find the rule to reduce by to get precedence of reduction  */
-  redprec = rprec[LAruleno[lookaheadnum]];
-
-  mask = 1;
-  fp1 = LA + lookaheadnum * tokensetsize;
-  fp2 = lookaheadset;
+  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;
+
   for (i = 0; i < ntokens; i++)
-    {
-      if ((mask & *fp2 & *fp1) && sprec[i])
+    if (bitset_test (lookaheads, i)
+	&& bitset_test (lookaheadset, 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 (sprec[i] < redprec)
-	    {
-	      log_resolution (state, lookaheadnum, i, _("reduce"));
-	      *fp2 &= ~mask;	/* flush the shift for this token */
-	      flush_shift (state, i);
-	    }
-	  else if (sprec[i] > redprec)
-	    {
-	      log_resolution (state, lookaheadnum, i, _("shift"));
-	      *fp1 &= ~mask;	/* flush the reduce for this token */
-	    }
-	  else
+	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)
 	    {
-	      /* Matching precedence levels.
-	         For left association, keep only the reduction.
-	         For right association, keep only the shift.
-	         For nonassociation, keep neither.  */
-
-	      switch (sassoc[i])
-		{
-		case right_assoc:
-		  log_resolution (state, lookaheadnum, i, _("shift"));
-		  break;
-
-		case left_assoc:
-		  log_resolution (state, lookaheadnum, i, _("reduce"));
-		  break;
-
-		case non_assoc:
-		  log_resolution (state, lookaheadnum, i, _("an error"));
-		  break;
-		}
-
-	      if (sassoc[i] != right_assoc)
-		{
-		  *fp2 &= ~mask;	/* flush the shift for this token */
-		  flush_shift (state, i);
-		}
-	      if (sassoc[i] != left_assoc)
-		{
-		  *fp1 &= ~mask;	/* flush the reduce for this token */
-		}
-	      if (sassoc[i] == non_assoc)
-		{
-		  /* Record an explicit error for this token.  */
-		  *errtokens++ = i;
-		}
+	    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 ();
 	    }
-	}
+      }
 
-      mask <<= 1;
-      if (mask == 0)
-	{
-	  mask = 1;
-	  fp2++;
-	  fp1++;
-	}
+  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);
     }
-  errp->nerrs = errtokens - errp->errs;
-  if (errp->nerrs)
+
+  if (obstack_object_size (&solved_conflicts_obstack))
     {
-      /* Some tokens have been explicitly made errors.  Allocate
-         a permanent errs structure for this state, to record them.  */
-      i = (char *) errtokens - (char *) errp;
-      err_table[state] = (errs *) xcalloc ((unsigned int) i, 1);
-      bcopy (errp, err_table[state], i);
+      obstack_1grow (&solved_conflicts_obstack, '\0');
+      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
     }
-  else
-    err_table[state] = 0;
-  free (errp);
 }
 
 
+/*-------------------------------------------------------------------.
+| 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).           |
+`-------------------------------------------------------------------*/
+
 static void
-set_conflicts (int state)
+set_conflicts (state *s, symbol **errors)
 {
   int i;
-  int k;
-  shifts *shiftp;
-  unsigned *fp2;
-  unsigned *fp3;
-  unsigned *fp4;
-  unsigned *fp1;
-  int symbol;
-
-  if (consistent[state])
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;
+
+  if (s->consistent)
     return;
 
-  for (i = 0; i < tokensetsize; i++)
-    lookaheadset[i] = 0;
+  bitset_zero (lookaheadset);
 
-  shiftp = shift_table[state];
-  if (shiftp)
-    {
-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
-	{
-	  symbol = accessing_symbol[shiftp->shifts[i]];
-	  if (ISVAR (symbol))
-	    break;
-	  SETBIT (lookaheadset, symbol);
-	}
-    }
-
-  k = lookaheads[state + 1];
-  fp4 = lookaheadset + tokensetsize;
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (lookaheadset, 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 = lookaheads[state]; i < k; i++)
-    if (rprec[LAruleno[i]])
-      {
-	fp1 = LA + i * tokensetsize;
-	fp2 = fp1;
-	fp3 = lookaheadset;
-
-	while (fp3 < fp4)
-	  {
-	    if (*fp2++ & *fp3++)
-	      {
-		resolve_sr_conflict (state, i);
-		break;
-	      }
-	  }
-      }
-
+     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);
 
   /* Loop over all rules which require lookahead in this state.  Check
      for conflicts not resolved above.  */
-  for (i = lookaheads[state]; i < k; i++)
+  for (i = 0; i < reds->num; ++i)
     {
-      fp1 = LA + i * tokensetsize;
-      fp2 = fp1;
-      fp3 = lookaheadset;
-
-      while (fp3 < fp4)
-	{
-	  if (*fp2++ & *fp3++)
-	    {
-	      conflicts[state] = 1;
-	      any_conflicts = 1;
-	    }
-	}
-
-      fp2 = fp1;
-      fp3 = lookaheadset;
+      if (!bitset_disjoint_p (reds->lookaheads[i], lookaheadset))
+	conflicts[s->number] = 1;
 
-      while (fp3 < fp4)
-	*fp3++ |= *fp2++;
+      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
-solve_conflicts (void)
+conflicts_solve (void)
 {
-  int i;
+  state_number i;
+  /* List of lookaheads on which we explicitly raise a syntax error.  */
+  symbol **errors = MALLOC (errors, ntokens + 1);
 
-  conflicts = XCALLOC (char, nstates);
-  shiftset = XCALLOC (unsigned, tokensetsize);
-  lookaheadset = XCALLOC (unsigned, tokensetsize);
+  CALLOC (conflicts, nstates);
+  shiftset = bitset_create (ntokens, BITSET_FIXED);
+  lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+  obstack_init (&solved_conflicts_obstack);
 
-  err_table = XCALLOC (errs *, nstates);
+  for (i = 0; i < nstates; i++)
+    {
+      set_conflicts (states[i], errors);
 
-  any_conflicts = 0;
+      /* 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);
+    }
 
-  for (i = 0; i < nstates; i++)
-    set_conflicts (i);
+  free (errors);
 }
 
 
@@ -284,461 +329,187 @@ solve_conflicts (void)
 | Count the number of shift/reduce conflicts.  |
 `---------------------------------------------*/
 
-static void
-count_sr_conflicts (int state)
+static int
+count_sr_conflicts (state *s)
 {
   int i;
-  int k;
-  int mask;
-  shifts *shiftp;
-  unsigned *fp1;
-  unsigned *fp2;
-  unsigned *fp3;
-  int symbol;
-
-  src_count = 0;
-
-  shiftp = shift_table[state];
-  if (!shiftp)
-    return;
+  int src_count = 0;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;
 
-  for (i = 0; i < tokensetsize; i++)
-    {
-      shiftset[i] = 0;
-      lookaheadset[i] = 0;
-    }
-
-  k = shiftp->nshifts;
-  for (i = 0; i < k; i++)
-    {
-      if (!shiftp->shifts[i])
-	continue;
-      symbol = accessing_symbol[shiftp->shifts[i]];
-      if (ISVAR (symbol))
-	break;
-      SETBIT (shiftset, symbol);
-    }
+  if (!trans)
+    return 0;
 
-  k = lookaheads[state + 1];
-  fp3 = lookaheadset + tokensetsize;
+  bitset_zero (lookaheadset);
+  bitset_zero (shiftset);
 
-  for (i = lookaheads[state]; i < k; i++)
-    {
-      fp1 = LA + i * tokensetsize;
-      fp2 = lookaheadset;
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (shiftset, TRANSITION_SYMBOL (trans, i));
 
-      while (fp2 < fp3)
-	*fp2++ |= *fp1++;
-    }
+  for (i = 0; i < reds->num; ++i)
+    bitset_or (lookaheadset, lookaheadset, reds->lookaheads[i]);
 
-  fp1 = shiftset;
-  fp2 = lookaheadset;
+  bitset_and (lookaheadset, lookaheadset, shiftset);
 
-  while (fp2 < fp3)
-    *fp2++ &= *fp1++;
+  src_count = bitset_count (lookaheadset);
 
-  mask = 1;
-  fp2 = lookaheadset;
-  for (i = 0; i < ntokens; i++)
-    {
-      if (mask & *fp2)
-	src_count++;
-
-      mask <<= 1;
-      if (mask == 0)
-	{
-	  mask = 1;
-	  fp2++;
-	}
-    }
+  return src_count;
 }
 
 
-/*----------------------------------------------.
-| Count the number of reduce/reduce conflicts.  |
-`----------------------------------------------*/
+/*----------------------------------------------------------------.
+| Count the number of reduce/reduce conflicts.  If ONE_PER_TOKEN, |
+| count one conflict for each token that has any reduce/reduce    |
+| conflicts.  Otherwise, count one conflict for each pair of      |
+| conflicting reductions.                                         |
++`----------------------------------------------------------------*/
 
-static void
-count_rr_conflicts (int state)
+static int
+count_rr_conflicts (state *s, bool one_per_token)
 {
   int i;
-  int j;
-  int count;
-  unsigned mask;
-  unsigned *baseword;
-  unsigned *wordp;
-  int m;
-  int n;
-
-  rrc_count = 0;
-
-  m = lookaheads[state];
-  n = lookaheads[state + 1];
-
-  if (n - m < 2)
-    return;
+  reductions *reds = s->reductions;
+  int rrc_count = 0;
 
-  mask = 1;
-  baseword = LA + m * tokensetsize;
   for (i = 0; i < ntokens; i++)
     {
-      wordp = baseword;
-
-      count = 0;
-      for (j = m; j < n; j++)
-	{
-	  if (mask & *wordp)
-	    count++;
-
-	  wordp += tokensetsize;
-	}
+      int count = 0;
+      int j;
+      for (j = 0; j < reds->num; ++j)
+	if (bitset_test (reds->lookaheads[j], i))
+	  count++;
 
       if (count >= 2)
-	rrc_count++;
-
-      mask <<= 1;
-      if (mask == 0)
-	{
-	  mask = 1;
-	  baseword++;
-	}
-    }
-}
-
-/*--------------------------------------------------------------.
-| Return a human readable string which reports shift/reduce and |
-| reduce/reduce conflict numbers (SRC_NUM, RRC_NUM).            |
-`--------------------------------------------------------------*/
-
-static const char *
-conflict_report (int src_num, int rrc_num)
-{
-  static char res[4096];
-  char *cp = res;
-
-  if (src_num == 1)
-    {
-      sprintf (cp, _(" 1 shift/reduce conflict"));
-      cp += strlen (cp);
-    }
-  else if (src_num > 1)
-    {
-      sprintf (cp, _(" %d shift/reduce conflicts"), src_num);
-      cp += strlen (cp);
+	rrc_count += one_per_token ? 1 : count-1;
     }
 
-  if (src_num > 0 && rrc_num > 0)
-    {
-      sprintf (cp, _(" and"));
-      cp += strlen (cp);
-    }
+  return rrc_count;
+}
 
-  if (rrc_num == 1)
-    {
-      sprintf (cp, _(" 1 reduce/reduce conflict"));
-      cp += strlen (cp);
-    }
-  else if (rrc_num > 1)
-    {
-      sprintf (cp, _(" %d reduce/reduce conflicts"), rrc_num);
-      cp += strlen (cp);
-    }
 
-  *cp++ = '.';
-  *cp++ = '\n';
-  *cp++ = '\0';
+/*--------------------------------------------------------.
+| Report the number of conflicts, using the Yacc format.  |
+`--------------------------------------------------------*/
 
-  return res;
+static void
+conflict_report (FILE *out, int src_num, int rrc_num)
+{
+  if (src_num && rrc_num)
+    fprintf (out, _("conflicts: %d shift/reduce, %d reduce/reduce\n"),
+	     src_num, rrc_num);
+  else if (src_num)
+    fprintf (out, _("conflicts: %d shift/reduce\n"), src_num);
+  else if (rrc_num)
+    fprintf (out, _("conflicts: %d reduce/reduce\n"), rrc_num);
 }
 
 
-/*---------------------------------------------.
-| Compute and give a report on the conflicts.  |
-`---------------------------------------------*/
+/*-----------------------------------------------------------.
+| Output the detailed description of states with conflicts.  |
+`-----------------------------------------------------------*/
 
 void
-print_conflicts (FILE *out)
+conflicts_output (FILE *out)
 {
-  int i;
-
-  src_total = 0;
-  rrc_total = 0;
-
-  /* Count the total number of conflicts, and if wanted, give a
-     detailed report in FOUTPUT.  */
+  bool printed_sth = false;
+  state_number i;
   for (i = 0; i < nstates; i++)
     {
+      state *s = states[i];
       if (conflicts[i])
 	{
-	  count_sr_conflicts (i);
-	  count_rr_conflicts (i);
-	  src_total += src_count;
-	  rrc_total += rrc_count;
-
-	  if (verbose_flag)
-	    {
-	      fprintf (out, _("State %d contains"), i);
-	      fputs (conflict_report (src_count, rrc_count), out);
-	    }
+	  fprintf (out, _("State %d "), i);
+	  conflict_report (out, count_sr_conflicts (s),
+			   count_rr_conflicts (s, true));
+	  printed_sth = true;
 	}
     }
-
-  /* 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);
-    }
-  else
-    {
-      fprintf (stderr, _("%s contains"), infile);
-      fputs (conflict_report (src_total, rrc_total), stderr);
-    }
+  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.						  |
+`--------------------------------------------------------*/
 
-void
-print_reductions (int state)
+int
+conflicts_total_count (void)
 {
-  int i;
-  int j;
-  int k;
-  unsigned *fp1;
-  unsigned *fp2;
-  unsigned *fp3;
-  unsigned *fp4;
-  int rule;
-  int symbol;
-  unsigned mask;
-  int m;
-  int n;
-  int default_LA;
-  int default_rule = 0;
-  int cmax;
+  state_number i;
   int count;
-  shifts *shiftp;
-  errs *errp;
-  int nodefault = 0;
-
-  for (i = 0; i < tokensetsize; i++)
-    shiftset[i] = 0;
-
-  shiftp = shift_table[state];
-  if (shiftp)
-    {
-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
-	{
-	  if (!shiftp->shifts[i])
-	    continue;
-	  symbol = accessing_symbol[shiftp->shifts[i]];
-	  if (ISVAR (symbol))
-	    break;
-	  /* if this state has a shift for the error token,
-	     don't use a default rule.  */
-	  if (symbol == error_token_number)
-	    nodefault = 1;
-	  SETBIT (shiftset, symbol);
-	}
-    }
 
-  errp = err_table[state];
-  if (errp)
-    {
-      k = errp->nerrs;
-      for (i = 0; i < k; i++)
-	{
-	  if (!errp->errs[i])
-	    continue;
-	  symbol = errp->errs[i];
-	  SETBIT (shiftset, symbol);
-	}
-    }
-
-  m = lookaheads[state];
-  n = lookaheads[state + 1];
-
-  if (n - m == 1 && !nodefault)
-    {
-      default_rule = LAruleno[m];
-
-      fp1 = LA + m * tokensetsize;
-      fp2 = shiftset;
-      fp3 = lookaheadset;
-      fp4 = lookaheadset + tokensetsize;
-
-      while (fp3 < fp4)
-	*fp3++ = *fp1++ & *fp2++;
-
-      mask = 1;
-      fp3 = lookaheadset;
+  /* Conflicts by state.  */
+  count = 0;
+  for (i = 0; i < nstates; i++)
+    if (conflicts[i])
+      {
+	count += count_sr_conflicts (states[i]);
+	count += count_rr_conflicts (states[i], false);
+      }
+  return count;
+}
 
-      for (i = 0; i < ntokens; i++)
-	{
-	  if (mask & *fp3)
-	    obstack_fgrow3 (&output_obstack,
-			    _("    %-4s\t[reduce using rule %d (%s)]\n"),
-			    tags[i], default_rule, tags[rlhs[default_rule]]);
 
-	  mask <<= 1;
-	  if (mask == 0)
-	    {
-	      mask = 1;
-	      fp3++;
-	    }
-	}
+/*------------------------------------------.
+| Reporting the total number of conflicts.  |
+`------------------------------------------*/
 
-      obstack_fgrow2 (&output_obstack,
-		      _("    $default\treduce using rule %d (%s)\n\n"),
-		      default_rule, tags[rlhs[default_rule]]);
-    }
-  else if (n - m >= 1)
-    {
-      cmax = 0;
-      default_LA = -1;
-      fp4 = lookaheadset + tokensetsize;
+void
+conflicts_print (void)
+{
+  /* 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.  */
+  bool src_ok = false;
 
-      if (!nodefault)
-	for (i = m; i < n; i++)
-	  {
-	    fp1 = LA + i * tokensetsize;
-	    fp2 = shiftset;
-	    fp3 = lookaheadset;
-
-	    while (fp3 < fp4)
-	      *fp3++ = *fp1++ & (~(*fp2++));
-
-	    count = 0;
-	    mask = 1;
-	    fp3 = lookaheadset;
-	    for (j = 0; j < ntokens; j++)
-	      {
-		if (mask & *fp3)
-		  count++;
-
-		mask <<= 1;
-		if (mask == 0)
-		  {
-		    mask = 1;
-		    fp3++;
-		  }
-	      }
-
-	    if (count > cmax)
-	      {
-		cmax = count;
-		default_LA = i;
-		default_rule = LAruleno[i];
-	      }
-
-	    fp2 = shiftset;
-	    fp3 = lookaheadset;
-
-	    while (fp3 < fp4)
-	      *fp2++ |= *fp3++;
-	  }
+  int src_total = 0;
+  int rrc_total = 0;
 
-      for (i = 0; i < tokensetsize; i++)
-	shiftset[i] = 0;
+  /* Conflicts by state.  */
+  {
+    state_number i;
 
-      if (shiftp)
+    for (i = 0; i < nstates; i++)
+      if (conflicts[i])
 	{
-	  k = shiftp->nshifts;
-	  for (i = 0; i < k; i++)
-	    {
-	      if (!shiftp->shifts[i])
-		continue;
-	      symbol = accessing_symbol[shiftp->shifts[i]];
-	      if (ISVAR (symbol))
-		break;
-	      SETBIT (shiftset, symbol);
-	    }
+	  src_total += count_sr_conflicts (states[i]);
+	  rrc_total += count_rr_conflicts (states[i], true);
 	}
+  }
 
-      mask = 1;
-      fp1 = LA + m * tokensetsize;
-      fp2 = shiftset;
-      for (i = 0; i < ntokens; i++)
-	{
-	  int defaulted = 0;
-
-	  if (mask & *fp2)
-	    count = 1;
-	  else
-	    count = 0;
-
-	  fp3 = fp1;
-	  for (j = m; j < n; j++)
-	    {
-	      if (mask & *fp3)
-		{
-		  if (count == 0)
-		    {
-		      if (j != default_LA)
-			{
-			  rule = LAruleno[j];
-			  obstack_fgrow3 (&output_obstack,
-				   _("    %-4s\treduce using rule %d (%s)\n"),
-				   tags[i], rule, tags[rlhs[rule]]);
-			}
-		      else
-			defaulted = 1;
-
-		      count++;
-		    }
-		  else
-		    {
-		      if (defaulted)
-			{
-			  rule = LAruleno[default_LA];
-			  obstack_fgrow3 (&output_obstack,
-				   _("    %-4s\treduce using rule %d (%s)\n"),
-				   tags[i], rule, tags[rlhs[rule]]);
-			  defaulted = 0;
-			}
-		      rule = LAruleno[j];
-		      obstack_fgrow3 (&output_obstack,
-			       _("    %-4s\t[reduce using rule %d (%s)]\n"),
-			       tags[i], rule, tags[rlhs[rule]]);
-		    }
-		}
-
-	      fp3 += tokensetsize;
-	    }
+  src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
 
-	  mask <<= 1;
-	  if (mask == 0)
-	    {
-	      mask = 1;
-	      /* We tried incrementing just fp1, and just fp2; both seem wrong.
-	         It seems necessary to increment both in sync.  */
-	      fp1++;
-	      fp2++;
-	    }
-	}
+  /* If there are no RR conflicts, and as many SR conflicts as
+     expected, then there is nothing to report.  */
+  if (!rrc_total && src_ok)
+    return;
 
-      if (default_LA >= 0)
-	obstack_fgrow2 (&output_obstack,
-			_("    $default\treduce using rule %d (%s)\n"),
-			default_rule, tags[rlhs[default_rule]]);
+  /* Report the total number of conflicts on STDERR.  */
+  if (! yacc_flag)
+    fprintf (stderr, "%s: ", current_file);
+  conflict_report (stderr, src_total, rrc_total);
 
-      obstack_1grow (&output_obstack, '\n');
+  if (expected_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"));
     }
 }
 
 
 void
-free_conflicts (void)
+conflicts_free (void)
 {
   XFREE (conflicts);
-  XFREE (shiftset);
-  XFREE (lookaheadset);
+  bitset_free (shiftset);
+  bitset_free (lookaheadset);
+  obstack_free (&solved_conflicts_obstack, NULL);
 }