2007-01-30 Paolo Bonzini <bonzini@gnu.org>

[bison.git] / src / conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index a054dbd04eee62171a9567f0917f889e53e84d17..7bb3e08ee585e74ec236ee381923372e1ea7f106 100644 (file)
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,769 +1,535 @@
-/* Find and resolve or report look-ahead conflicts for bison,
-   Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+/* Find and resolve or report lookahead conflicts for bison,

 
 

-This file is part of Bison, the GNU Compiler Compiler.
+   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+   Free Software Foundation, Inc.

 
 

-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 file is part of Bison, the GNU Compiler Compiler.

 
 

-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.
+   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.

 
 

-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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   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.

 
 

-#ifdef _AIX
- #pragma alloca
-#endif
-#include <stdio.h>
+   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.  */
+
+#include <config.h>

 #include "system.h"
 #include "system.h"

-#include "machine.h"
-#include "new.h"
+
+#include <bitset.h>
+
+#include "LR0.h"
+#include "complain.h"
+#include "conflicts.h"

 #include "files.h"
 #include "files.h"

+#include "getargs.h"

 #include "gram.h"
 #include "gram.h"

+#include "lalr.h"
+#include "reader.h"

 #include "state.h"
 #include "state.h"

+#include "symtab.h"

 
 

+/* -1 stands for not specified. */
+int expected_sr_conflicts = -1;
+int expected_rr_conflicts = -1;
+static char *conflicts;
+static struct obstack solved_conflicts_obstack;

 
 

-#ifndef __GNUC__
-#undef alloca
-#define alloca __builtin_alloca
-#else
-#ifdef HAVE_ALLOCA_H
-#include <alloca.h>
-#else
-#ifndef _AIX
-extern char *alloca ();
-#endif
-#endif
-#endif
-
-extern char **tags;
-extern int tokensetsize;
-extern char *consistent;
-extern short *accessing_symbol;
-extern shifts **shift_table;
-extern unsigned *LA;
-extern short *LAruleno;
-extern short *lookaheads;
-extern int verboseflag;
-
-void set_conflicts();
-void resolve_sr_conflict();
-void flush_shift();
-void log_resolution();
-void total_conflicts();
-void count_sr_conflicts();
-void count_rr_conflicts();
-
-char any_conflicts;
-char *conflicts;
-errs **err_table;
-int expected_conflicts;
-
-
-static unsigned *shiftset;
-static unsigned *lookaheadset;
-static int src_total;
-static int rrc_total;
-static int src_count;
-static int rrc_count;
+static bitset shift_set;
+static bitset lookahead_set;

 
 

+\f

 
 

-void
-initialize_conflicts()
-{
-  register int i;
-/*  register errs *sp; JF unused */
-
-  conflicts = NEW2(nstates, char);
-  shiftset = NEW2(tokensetsize, unsigned);
-  lookaheadset = NEW2(tokensetsize, unsigned);
+enum conflict_resolution
+  {
+    shift_resolution,
+    reduce_resolution,
+    left_resolution,
+    right_resolution,
+    nonassoc_resolution
+  };

 
 

-  err_table = NEW2(nstates, errs *);

 
 

-  any_conflicts = 0;
+/*----------------------------------------------------------------.
+| Explain how an SR conflict between TOKEN and RULE was resolved: |
+| RESOLUTION.                                                     |
+`----------------------------------------------------------------*/

 
 

-  for (i = 0; i < nstates; i++)
-    set_conflicts(i);
-}
-
-
-void
-set_conflicts(state)
-int state;
+static inline void
+log_resolution (rule *r, symbol_number token,
+               enum conflict_resolution resolution)

 {
 {

-  register int i;
-  register int k;
-  register shifts *shiftp;
-  register unsigned *fp2;
-  register unsigned *fp3;
-  register unsigned *fp4;
-  register unsigned *fp1;
-  register int symbol;
-
-  if (consistent[state]) return;
-
-  for (i = 0; i < tokensetsize; i++)
-    lookaheadset[i] = 0;
-
-  shiftp = shift_table[state];
-  if (shiftp)
+  if (report_flag & report_solved_conflicts)

     {
     {

-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
+      /* The description of the resolution. */
+      switch (resolution)

        {
        {

-         symbol = accessing_symbol[shiftp->shifts[i]];
-         if (ISVAR(symbol)) break;
-         SETBIT(lookaheadset, symbol);
+       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;

        }
        }

-    }
-
-  k = lookaheads[state + 1];
-  fp4 = lookaheadset + tokensetsize;

 
 

-  /* loop over all rules which require lookahead in this state */
-  /* first check for shift-reduce conflict, and try to resolve using precedence  */
+      /* 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");
+    }
+}

 
 

-  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;
-             }
-         }
-      }

 
 

-  /* loop over all rules which require lookahead in this state */
-  /* Check for conflicts not resolved above.  */
+/*------------------------------------------------------------------.
+| 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.                                           |
+`------------------------------------------------------------------*/

 
 

-  for (i = lookaheads[state]; i < k; i++)
-    {
-      fp1 = LA + i * tokensetsize;
-      fp2 = fp1;
-      fp3 = lookaheadset;
+static void
+flush_shift (state *s, int token)
+{
+  transitions *trans = s->transitions;
+  int i;
+
+  bitset_reset (lookahead_set, token);
+  for (i = 0; i < trans->num; i++)
+    if (!TRANSITION_IS_DISABLED (trans, i)
+       && TRANSITION_SYMBOL (trans, i) == token)
+      TRANSITION_DISABLE (trans, i);
+}

 
 

-      while (fp3 < fp4)
-       {
-         if (*fp2++ & *fp3++)
-           {
-             conflicts[state] = 1;
-             any_conflicts = 1;
-           }
-       }

 
 

-      fp2 = fp1;
-      fp3 = lookaheadset;
+/*--------------------------------------------------------------------.
+| 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.                                              |
+`--------------------------------------------------------------------*/

 
 

-      while (fp3 < fp4)
-       *fp3++ |= *fp2++;
-    }
+static void
+flush_reduce (bitset lookahead_tokens, int token)
+{
+  bitset_reset (lookahead_tokens, token);

 }
 
 
 }
 
 

+/*------------------------------------------------------------------.
+| Attempt to resolve shift-reduce conflict for one rule by means of |
+| 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.     |
+|                                                                   |
+| RULENO is the number of the lookahead bitset to consider.         |
+|                                                                   |
+| ERRORS can be used to store discovered explicit errors.           |
+`------------------------------------------------------------------*/

 
 

-/* Attempt to resolve shift-reduce conflict for one rule
-by means of 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.  */
-
-void
-resolve_sr_conflict(state, lookaheadnum)
-int state;
-int lookaheadnum;
+static void
+resolve_sr_conflict (state *s, int ruleno, symbol **errors)

 {
 {

-  register int i;
-  register int mask;
-  register unsigned *fp1;
-  register unsigned *fp2;
-  register int redprec;
-  /* Extra parens avoid errors on Ultrix 4.3.  */
-  errs *errp = (errs *) alloca ((sizeof(errs) + ntokens * sizeof(short)));
-  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 lookahead_tokens = reds->lookahead_tokens[ruleno];
+  int nerrs = 0;
+

   for (i = 0; i < ntokens; i++)
   for (i = 0; i < ntokens; i++)

-    {
-      if ((mask & *fp2 & *fp1) && sprec[i])
+    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.  */
        /* 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)
-           {
-             if (verboseflag) log_resolution(state, lookaheadnum, i, "reduce");
-             *fp2 &= ~mask;  /* flush the shift for this token */
-             flush_shift(state, i);
-           }
-         else if (sprec[i] > redprec)
-           {
-             if (verboseflag) 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 (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.  */
+
+         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:
-                 if (verboseflag) log_resolution(state, lookaheadnum, i, "shift");
-                 break;
-
-               case LEFT_ASSOC:
-                 if (verboseflag) log_resolution(state, lookaheadnum, i, "reduce");
-                 break;
-
-               case NON_ASSOC:
-                 if (verboseflag) 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;
-               }
+           default:
+             abort ();
+
+           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;

            }
            }

-       }
+      }

 
 

-      mask <<= 1;
-      if (mask == 0)
-       {
-         mask = 1;
-         fp2++;  fp1++;
-       }
-    }
-  errp->nerrs = errtokens - errp->errs;
-  if (errp->nerrs)
+  if (nerrs)

     {
     {

-      /* 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 *) xmalloc ((unsigned int)i);
-      bcopy (errp, err_table[state], i);
+      /* Some tokens have been explicitly made errors.  Allocate a
+        permanent errs structure for this state, to record them.  */
+      state_errs_set (s, nerrs, errors);

     }
     }

-  else
-    err_table[state] = 0;
-}
-
-

 
 

-/* 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.  */
-
-void
-flush_shift(state, token)
-int state;
-int token;
-{
-  register shifts *shiftp;
-  register int k, i;
-/*  register unsigned symbol; JF unused */
-
-  shiftp = shift_table[state];
-
-  if (shiftp)
+  if (obstack_object_size (&solved_conflicts_obstack))

     {
     {

-      k = shiftp->nshifts;
-      for (i = 0; i < k; i++)
-       {
-         if (shiftp->shifts[i] && token == accessing_symbol[shiftp->shifts[i]])
-           (shiftp->shifts[i]) = 0;
-       }
+      obstack_1grow (&solved_conflicts_obstack, '\0');
+      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);

     }
 }
 
 
     }
 }
 
 

-void
-log_resolution(state, LAno, token, resolution)
-int state, LAno, token;
-char *resolution;
+/*-------------------------------------------------------------------.
+| 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   |
+| lookahead tokens on which S raises a syntax error (%nonassoc).     |
+`-------------------------------------------------------------------*/
+
+static void
+set_conflicts (state *s, symbol **errors)

 {
 {

-  fprintf(foutput,
-         "Conflict in state %d between rule %d and token %s resolved as %s.\n",
-         state, LAruleno[LAno], tags[token], resolution);
-}
+  int i;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;

 
 

+  if (s->consistent)
+    return;

 
 

-void
-conflict_log()
-{
-  register int i;
+  bitset_zero (lookahead_set);

 
 

-  src_total = 0;
-  rrc_total = 0;
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, i));

 
 

-  for (i = 0; i < nstates; 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->lookahead_tokens[i], lookahead_set))
+      resolve_sr_conflict (s, i, errors);
+
+  /* Loop over all rules which require lookahead in this state.  Check
+     for conflicts not resolved above.  */
+  for (i = 0; i < reds->num; ++i)

     {
     {

-      if (conflicts[i])
-       {
-         count_sr_conflicts(i);
-         count_rr_conflicts(i);
-         src_total += src_count;
-         rrc_total += rrc_count;
-       }
-    }
+      if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
+       conflicts[s->number] = 1;

 
 

-  total_conflicts();
+      bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);
+    }

 }
 }

-  
+
+
+/*----------------------------------------------------------------.
+| Solve all the S/R conflicts using the precedence/associativity, |
+| and flag as inconsistent the states that still have conflicts.  |
+`----------------------------------------------------------------*/

 
 void
 
 void

-verbose_conflict_log()
+conflicts_solve (void)

 {
 {

-  register int i;
+  state_number i;
+  /* List of lookahead tokens on which we explicitly raise a syntax error.  */
+  symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);

 
 

-  src_total = 0;
-  rrc_total = 0;
+  conflicts = xcalloc (nstates, sizeof *conflicts);
+  shift_set = bitset_create (ntokens, BITSET_FIXED);
+  lookahead_set = bitset_create (ntokens, BITSET_FIXED);
+  obstack_init (&solved_conflicts_obstack);

 
   for (i = 0; i < nstates; i++)
     {
 
   for (i = 0; i < nstates; i++)
     {

-      if (conflicts[i])
-       {
-         count_sr_conflicts(i);
-         count_rr_conflicts(i);
-         src_total += src_count;
-         rrc_total += rrc_count;
-
-         fprintf(foutput, "State %d contains", i);
+      set_conflicts (states[i], errors);

 
 

-         if (src_count == 1)
-           fprintf(foutput, " 1 shift/reduce conflict");
-         else if (src_count > 1)
-           fprintf(foutput, " %d shift/reduce conflicts", src_count);
-
-         if (src_count > 0 && rrc_count > 0)
-           fprintf(foutput, " and");
-
-         if (rrc_count == 1)
-           fprintf(foutput, " 1 reduce/reduce conflict");
-         else if (rrc_count > 1)
-           fprintf(foutput, " %d reduce/reduce conflicts", rrc_count);
-
-         putc('.', foutput);
-         putc('\n', foutput);
-       }
+      /* 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);

     }
 
     }
 

-  total_conflicts();
+  free (errors);

 }
 
 
 }
 
 

-void
-total_conflicts()
+/*---------------------------------------------.
+| Count the number of shift/reduce conflicts.  |
+`---------------------------------------------*/
+
+static int
+count_sr_conflicts (state *s)

 {
 {

-  extern int fixed_outfiles;
+  int i;
+  int src_count = 0;
+  transitions *trans = s->transitions;
+  reductions *reds = s->reductions;

 
 

-  if (src_total == expected_conflicts && rrc_total == 0)
-    return;
+  if (!trans)
+    return 0;

 
 

-  if (fixed_outfiles)
-    {
-      /* If invoked under the name `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);
+  bitset_zero (lookahead_set);
+  bitset_zero (shift_set);

 
 

-      if (src_total == 1)
-       fprintf(stderr, " 1 shift/reduce conflict");
-      else if (src_total > 1)
-       fprintf(stderr, " %d shift/reduce conflicts", src_total);
+  FOR_EACH_SHIFT (trans, i)
+    bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));

 
 

-      if (src_total > 0 && rrc_total > 0)
-       fprintf(stderr, " and");
+  for (i = 0; i < reds->num; ++i)
+    bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);

 
 

-      if (rrc_total == 1)
-       fprintf(stderr, " 1 reduce/reduce conflict");
-      else if (rrc_total > 1)
-       fprintf(stderr, " %d reduce/reduce conflicts", rrc_total);
+  bitset_and (lookahead_set, lookahead_set, shift_set);

 
 

-      putc('.', stderr);
-      putc('\n', stderr);
-    }
+  src_count = bitset_count (lookahead_set);
+
+  return src_count;

 }
 
 
 }
 
 

-void
-count_sr_conflicts(state)
-int state;
-{
-  register int i;
-  register int k;
-  register int mask;
-  register shifts *shiftp;
-  register unsigned *fp1;
-  register unsigned *fp2;
-  register unsigned *fp3;
-  register int symbol;
+/*----------------------------------------------------------------.
+| 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.                                         |
++`----------------------------------------------------------------*/

 
 

-  src_count = 0;
-
-  shiftp = shift_table[state];
-  if (!shiftp) return;
+static int
+count_rr_conflicts (state *s, bool one_per_token)
+{
+  int i;
+  reductions *reds = s->reductions;
+  int rrc_count = 0;

 
 

-  for (i = 0; i < tokensetsize; i++)
+  for (i = 0; i < ntokens; i++)

     {
     {

-      shiftset[i] = 0;
-      lookaheadset[i] = 0;
+      int count = 0;
+      int j;
+      for (j = 0; j < reds->num; ++j)
+       if (bitset_test (reds->lookahead_tokens[j], i))
+         count++;
+
+      if (count >= 2)
+       rrc_count += one_per_token ? 1 : count-1;

     }
 
     }
 

-  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);
-    }
+  return rrc_count;
+}

 
 

-  k = lookaheads[state + 1];
-  fp3 = lookaheadset + tokensetsize;

 
 

-  for (i = lookaheads[state]; i < k; i++)
-    {
-      fp1 = LA + i * tokensetsize;
-      fp2 = lookaheadset;
+/*--------------------------------------------------------.
+| Report the number of conflicts, using the Yacc format.  |
+`--------------------------------------------------------*/

 
 

-      while (fp2 < fp3)
-       *fp2++ |= *fp1++;
-    }
+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);
+}

 
 

-  fp1 = shiftset;
-  fp2 = lookaheadset;

 
 

-  while (fp2 < fp3)
-    *fp2++ &= *fp1++;
+/*-----------------------------------------------------------.
+| Output the detailed description of states with conflicts.  |
+`-----------------------------------------------------------*/

 
 

-  mask = 1;
-  fp2 = lookaheadset;
-  for (i = 0; i < ntokens; i++)
+void
+conflicts_output (FILE *out)
+{
+  bool printed_sth = false;
+  state_number i;
+  for (i = 0; i < nstates; i++)

     {
     {

-      if (mask & *fp2)
-       src_count++;
-
-      mask <<= 1;
-      if (mask == 0)
+      state *s = states[i];
+      if (conflicts[i])

        {
        {

-         mask = 1;
-         fp2++;
+         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.                                              |
+`--------------------------------------------------------*/

 
 

-void
-count_rr_conflicts(state)
-int state;
+int
+conflicts_total_count (void)

 {
 {

-  register int i;
-  register int j;
-  register int count;
-  register unsigned mask;
-  register unsigned *baseword;
-  register unsigned *wordp;
-  register int m;
-  register int n;
-
-  rrc_count = 0;
-
-  m = lookaheads[state];
-  n = lookaheads[state + 1];
-
-  if (n - m < 2) return;
-
-  mask = 1;
-  baseword = LA + m * tokensetsize;
-  for (i = 0; i < ntokens; i++)
-    {
-      wordp = baseword;
+  state_number i;
+  int count;

 
 

-      count = 0;
-      for (j = m; j < n; j++)
-       {
-         if (mask & *wordp)
-           count++;
-
-         wordp += tokensetsize;
-       }
-
-      if (count >= 2) rrc_count++;
-
-      mask <<= 1;
-      if (mask == 0)
-       {
-         mask = 1;
-         baseword++;
-       }
-    }
+  /* 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;

 }
 
 
 }
 
 

+/*------------------------------------------.
+| Reporting the total number of conflicts.  |
+`------------------------------------------*/
+

 void
 void

-print_reductions(state)
-int state;
+conflicts_print (void)

 {
 {

-  register int i;
-  register int j;
-  register int k;
-  register unsigned *fp1;
-  register unsigned *fp2;
-  register unsigned *fp3;
-  register unsigned *fp4;
-  register int rule;
-  register int symbol;
-  register unsigned mask;
-  register int m;
-  register int n;
-  register int default_LA;
-  register int default_rule;
-  register int cmax;
-  register int count;
-  register shifts *shiftp;
-  register 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++)
+  /* 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;
+  bool rrc_ok;
+
+  int src_total = 0;
+  int rrc_total = 0;
+  int src_expected;
+  int rrc_expected;
+
+  /* Conflicts by state.  */
+  {
+    state_number i;
+
+    for (i = 0; i < nstates; i++)
+      if (conflicts[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);
+         src_total += count_sr_conflicts (states[i]);
+         rrc_total += count_rr_conflicts (states[i], true);

        }
        }

-    }
+  }

 
 

-  errp = err_table[state];
-  if (errp)
+  if (! glr_parser && rrc_total > 0 && expected_rr_conflicts != -1)

     {
     {

-      k = errp->nerrs;
-      for (i = 0; i < k; i++)
-       {
-         if (! errp->errs[i]) continue;
-         symbol = errp->errs[i];
-         SETBIT(shiftset, symbol);
-       }
+      warn (_("%%expect-rr applies only to GLR parsers"));
+      expected_rr_conflicts = -1;

     }
 
     }
 

-  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++;
+  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;

 
 

-      mask = 1;
-      fp3 = lookaheadset;
-
-      for (i = 0; i < ntokens; i++)
-       {
-         if (mask & *fp3)
-           fprintf(foutput, "    %-4s\t[reduce using rule %d (%s)]\n",
-                   tags[i], default_rule, tags[rlhs[default_rule]]);
-
-         mask <<= 1;
-         if (mask == 0)
-           {
-             mask = 1;
-             fp3++;
-           }
-       }
+  /* If there are as many RR conflicts and SR conflicts as
+     expected, then there is nothing to report.  */
+  if (rrc_ok & src_ok)
+    return;

 
 

-      fprintf(foutput, "    $default\treduce using rule %d (%s)\n\n",
-             default_rule, tags[rlhs[default_rule]]);
-    }
-  else if (n - m >= 1)
+  /* Report the total number of conflicts on STDERR.  */
+  if (src_total | rrc_total)

     {
     {

-      cmax = 0;
-      default_LA = -1;
-      fp4 = lookaheadset + tokensetsize;
-
-      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++;
-         }
-
-      for (i = 0; i < tokensetsize; i++)
-        shiftset[i] = 0;
-
-      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;
-             SETBIT(shiftset, symbol);
-           }
-        }
-
-      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];
-                         fprintf(foutput, "    %-4s\treduce using rule %d (%s)\n",
-                                 tags[i], rule, tags[rlhs[rule]]);
-                       }
-                     else defaulted = 1;
-
-                     count++;
-                   }
-                 else
-                   {
-                     if (defaulted)
-                       {
-                         rule = LAruleno[default_LA];
-                         fprintf(foutput, "    %-4s\treduce using rule %d (%s)\n",
-                                 tags[i], rule, tags[rlhs[rule]]);
-                         defaulted = 0;
-                       }
-                     rule = LAruleno[j];
-                     fprintf(foutput, "    %-4s\t[reduce using rule %d (%s)]\n",
-                             tags[i], rule, tags[rlhs[rule]]);
-                   }
-               }
-
-             fp3 += tokensetsize;
-           }
-
-         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 (default_LA >= 0)
-       {
-         fprintf(foutput, "    $default\treduce using rule %d (%s)\n",
-                 default_rule, tags[rlhs[default_rule]]);
-       }
+      if (! yacc_flag)
+       fprintf (stderr, "%s: ", current_file);
+      conflict_report (stderr, src_total, rrc_total);
+    }

 
 

-      putc('\n', foutput);
+  if (expected_sr_conflicts != -1 || expected_rr_conflicts != -1)
+    {
+      if (! src_ok)
+       complain (ngettext ("expected %d shift/reduce conflict",
+                           "expected %d shift/reduce conflicts",
+                           src_expected),
+                 src_expected);
+      if (! rrc_ok)
+       complain (ngettext ("expected %d reduce/reduce conflict",
+                           "expected %d reduce/reduce conflicts",
+                           rrc_expected),
+                 rrc_expected);

     }
 }
 
 
 void
     }
 }
 
 
 void

-finalize_conflicts()
+conflicts_free (void)

 {
 {

-  FREE(conflicts);
-  FREE(shiftset);
-  FREE(lookaheadset);
+  free (conflicts);
+  bitset_free (shift_set);
+  bitset_free (lookahead_set);
+  obstack_free (&solved_conflicts_obstack, NULL);

 }
 }