* src/state.h (state_t): `solved_conflicts' is a new member.

[bison.git] / src / conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index 6542c943aa6ee6ce600036b9b8f7ca2e2749a721..0ba2e5ac4315ec8953341395a4d188842810cd5d 100644 (file)
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,5 +1,6 @@
 /* Find and resolve or report look-ahead conflicts for bison,
 /* 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
+   Free Software Foundation, Inc.

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


@@ -19,8 +20,10 @@
    02111-1307, USA.  */
 
 #include "system.h"
    02111-1307, USA.  */
 
 #include "system.h"

+#include "bitset.h"

 #include "complain.h"
 #include "getargs.h"
 #include "complain.h"
 #include "getargs.h"

+#include "symtab.h"

 #include "files.h"
 #include "gram.h"
 #include "state.h"
 #include "files.h"
 #include "gram.h"
 #include "state.h"


@@ -32,18 +35,93 @@
 /* -1 stands for not specified. */
 int expected_conflicts = -1;
 static char *conflicts = NULL;
 /* -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;

 \f
 
 \f
 

+enum conflict_resolution_e
+  {
+    shift_resolution,
+    reduce_resolution,
+    left_resolution,
+    right_resolution,
+    nonassoc_resolution,
+  };
+
+

 static inline void
 static inline void

-log_resolution (int state, int LAno, int token, char *resolution)
+log_resolution (int lookahead, int token,
+               enum conflict_resolution_e 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 left_resolution:
+         obstack_fgrow2 (&solved_conflicts_obstack,
+                         _("\
+    Conflict between rule %d and token %s resolved as shift"),
+                         LArule[lookahead]->number,
+                         symbols[token]->tag);
+         break;
+       case reduce_resolution:
+       case right_resolution:
+         obstack_fgrow2 (&solved_conflicts_obstack,
+                         _("\
+    Conflict between rule %d and token %s resolved as reduce"),
+                         LArule[lookahead]->number,
+                         symbols[token]->tag);
+         break;
+       case nonassoc_resolution:
+         obstack_fgrow2 (&solved_conflicts_obstack,
+                         _("\
+    Conflict between rule %d and token %s resolved as an error"),
+                         LArule[lookahead]->number,
+                         symbols[token]->tag);
+         break;
+       }
+
+      /* The reason. */
+      switch (resolution)
+       {
+       case shift_resolution:
+         obstack_fgrow2 (&solved_conflicts_obstack,
+                         " (%s < %s)",
+                         LArule[lookahead]->prec->tag,
+                         symbols[token]->tag);
+         break;
+
+       case reduce_resolution:
+         obstack_fgrow2 (&solved_conflicts_obstack,
+                         " (%s < %s)",
+                         symbols[token]->tag,
+                         LArule[lookahead]->prec->tag);
+         break;
+
+       case left_resolution:
+         obstack_printf (&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");
+    }

 }
 
 
 }
 
 


@@ -54,17 +132,31 @@ Conflict in state %d between rule %d and token %s resolved as %s.\n"),
 `------------------------------------------------------------------*/
 
 static void
 `------------------------------------------------------------------*/
 
 static void

-flush_shift (int state, int token)
+flush_shift (state_t *state, int token)

 {
 {

-  shifts *shiftp = state_table[state]->shifts;
+  shifts *shiftp = state->shifts;

   int i;
 
   int i;
 

+  bitset_reset (lookaheadset, token);

   for (i = 0; i < shiftp->nshifts; i++)
     if (!SHIFT_IS_DISABLED (shiftp, i) && SHIFT_SYMBOL (shiftp, i) == token)
       SHIFT_DISABLE (shiftp, i);
 }
 
 
   for (i = 0; i < shiftp->nshifts; i++)
     if (!SHIFT_IS_DISABLED (shiftp, i) && SHIFT_SYMBOL (shiftp, i) == token)
       SHIFT_DISABLE (shiftp, 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.                                             |
+`-------------------------------------------------------------------*/
+
+static void
+flush_reduce (int lookahead, int token)
+{
+  bitset_reset (LA[lookahead], token);
+}
+
+

 /*------------------------------------------------------------------.
 | Attempt to resolve shift-reduce conflict for one rule by means of |
 | precedence declarations.  It has already been checked that the    |
 /*------------------------------------------------------------------.
 | Attempt to resolve shift-reduce conflict for one rule by means of |
 | precedence declarations.  It has already been checked that the    |


@@ -73,144 +165,124 @@ flush_shift (int state, int token)
 `------------------------------------------------------------------*/
 
 static void
 `------------------------------------------------------------------*/
 
 static void

-resolve_sr_conflict (int state, int lookaheadnum)
+resolve_sr_conflict (state_t *state, int lookahead)

 {
   int i;
   /* find the rule to reduce by to get precedence of reduction  */
 {
   int i;
   /* find the rule to reduce by to get precedence of reduction  */

-  int redprec = rule_table[LAruleno[lookaheadnum]].prec;
-  errs *errp = ERRS_ALLOC (ntokens + 1);
-  short *errtokens = errp->errs;
+  int redprec = LArule[lookahead]->prec->prec;
+  errs *errp = errs_new (ntokens + 1);
+  errp->nerrs = 0;

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

-    if (BITISSET (LA (lookaheadnum), i)
-       && BITISSET (lookaheadset, i)
-       && sprec[i])
-      /* Shift-reduce conflict occurs for token number i
-        and it has a precedence.
-        The precedence of shifting is that of token i.  */
+    if (bitset_test (LA[lookahead], i)
+       && bitset_test (lookaheadset, i)
+       && symbols[i]->prec)

       {
       {

-       if (sprec[i] < redprec)
+       /* 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 (state, lookaheadnum, i, _("reduce"));
-           /* flush the shift for this token */
-           RESETBIT (lookaheadset, i);
+           log_resolution (lookahead, i, reduce_resolution);

            flush_shift (state, i);
          }
            flush_shift (state, i);
          }

-       else if (sprec[i] > redprec)
+       else if (symbols[i]->prec > redprec)

          {
          {

-           log_resolution (state, lookaheadnum, i, _("shift"));
-           /* flush the reduce for this token */
-           RESETBIT (LA (lookaheadnum), i);
+           log_resolution (lookahead, i, shift_resolution);
+           flush_reduce (lookahead, i);

          }
        else
          }
        else

-         {
-           /* 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)
-             {
-               /* flush the shift for this token */
-               RESETBIT (lookaheadset, i);
-               flush_shift (state, i);
-             }
-           if (sassoc[i] != left_assoc)
-             {
-               /* flush the reduce for this token */
-               RESETBIT (LA (lookaheadnum), i);
-             }
-           if (sassoc[i] == non_assoc)
-             {
-               /* Record an explicit error for this token.  */
-               *errtokens++ = i;
-             }
-         }
+         /* 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 (lookahead, i, right_resolution);
+             flush_reduce (lookahead, i);
+             break;
+
+           case left_assoc:
+             log_resolution (lookahead, i, left_resolution);
+             flush_shift (state, i);
+             break;
+
+           case non_assoc:
+             log_resolution (lookahead, i, nonassoc_resolution);
+             flush_shift (state, i);
+             flush_reduce (lookahead, i);
+             /* Record an explicit error for this token.  */
+             errp->errs[errp->nerrs++] = i;
+             break;
+           }

       }
 
       }
 

-  errp->nerrs = errtokens - errp->errs;

   /* Some tokens have been explicitly made errors.  Allocate a
      permanent errs structure for this state, to record them.  */
   /* Some tokens have been explicitly made errors.  Allocate a
      permanent errs structure for this state, to record them.  */

-  i = (char *) errtokens - (char *) errp;
-  state_table[state]->errs = ERRS_ALLOC (i + 1);
-  memcpy (state_table[state]->errs, errp, i);
+  state->errs = errs_dup (errp);

   free (errp);
   free (errp);

+
+  if (obstack_object_size (&solved_conflicts_obstack))
+    {
+      obstack_1grow (&solved_conflicts_obstack, '\0');
+      state->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+    }

 }
 
 
 static void
 }
 
 
 static void

-set_conflicts (int state)
+set_conflicts (state_t *state)

 {
 {

-  int i, j;
+  int i;

   shifts *shiftp;
 
   shifts *shiftp;
 

-  if (state_table[state]->consistent)
+  if (state->consistent)

     return;
 
     return;
 

-  for (i = 0; i < tokensetsize; i++)
-    lookaheadset[i] = 0;
+  bitset_zero (lookaheadset);

 
 

-  shiftp = state_table[state]->shifts;
+  shiftp = state->shifts;

   for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
     if (!SHIFT_IS_DISABLED (shiftp, i))
   for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
     if (!SHIFT_IS_DISABLED (shiftp, i))

-      SETBIT (lookaheadset, SHIFT_SYMBOL (shiftp, i));
+      bitset_set (lookaheadset, SHIFT_SYMBOL (shiftp, i));

 
   /* Loop over all rules which require lookahead in this state.  First
      check for shift-reduce conflict, and try to resolve using
      precedence */
 
   /* Loop over all rules which require lookahead in this state.  First
      check for shift-reduce conflict, and try to resolve using
      precedence */

-  for (i = state_table[state]->lookaheads;
-       i < state_table[state + 1]->lookaheads;
-       ++i)
-    if (rule_table[LAruleno[i]].prec)
-      for (j = 0; j < tokensetsize; ++j)
-       if (LA (i)[j] & lookaheadset[j])
-         {
-           resolve_sr_conflict (state, i);
-           break;
-         }
-
+  for (i = 0; i < state->nlookaheads; ++i)
+    if (LArule[state->lookaheadsp + i]->prec
+       && LArule[state->lookaheadsp + i]->prec->prec
+       && !bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset))
+      {
+       resolve_sr_conflict (state, state->lookaheadsp + i);
+       break;
+      }

 
   /* Loop over all rules which require lookahead in this state.  Check
      for conflicts not resolved above.  */
 
   /* Loop over all rules which require lookahead in this state.  Check
      for conflicts not resolved above.  */

-  for (i = state_table[state]->lookaheads;
-       i < state_table[state + 1]->lookaheads;
-       ++i)
+  for (i = 0; i < state->nlookaheads; ++i)

     {
     {

-      for (j = 0; j < tokensetsize; ++j)
-       if (LA (i)[j] & lookaheadset[j])
-         conflicts[state] = 1;
+      if (!bitset_disjoint_p (LA[state->lookaheadsp + i], lookaheadset))
+       conflicts[state->number] = 1;

 
 

-      for (j = 0; j < tokensetsize; ++j)
-       lookaheadset[j] |= LA (i)[j];
+      bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]);

     }
 }
 
 void
     }
 }
 
 void

-solve_conflicts (void)
+conflicts_solve (void)

 {
 {

-  int i;
+  size_t i;

 
   conflicts = XCALLOC (char, nstates);
 
   conflicts = XCALLOC (char, nstates);

-  shiftset = XCALLOC (unsigned, tokensetsize);
-  lookaheadset = XCALLOC (unsigned, tokensetsize);
+  shiftset = bitset_create (ntokens, BITSET_FIXED);
+  lookaheadset = bitset_create (ntokens, BITSET_FIXED);
+  obstack_init (&solved_conflicts_obstack);

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

-    set_conflicts (i);
+    set_conflicts (states[i]);

 }
 
 
 }
 
 


@@ -219,37 +291,28 @@ solve_conflicts (void)
 `---------------------------------------------*/
 
 static int
 `---------------------------------------------*/
 
 static int

-count_sr_conflicts (int state)
+count_sr_conflicts (state_t *state)

 {
 {

-  int i, k;
+  int i;

   int src_count = 0;
   int src_count = 0;

-  shifts *shiftp = state_table[state]->shifts;
+  shifts *shiftp = state->shifts;

 
   if (!shiftp)
     return 0;
 
 
   if (!shiftp)
     return 0;
 

-  for (i = 0; i < tokensetsize; i++)
-    {
-      shiftset[i] = 0;
-      lookaheadset[i] = 0;
-    }
+  bitset_zero (lookaheadset);
+  bitset_zero (shiftset);

 
   for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
     if (!SHIFT_IS_DISABLED (shiftp, i))
 
   for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
     if (!SHIFT_IS_DISABLED (shiftp, i))

-      SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
+      bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i));

 
 

-  for (i = state_table[state]->lookaheads;
-       i < state_table[state + 1]->lookaheads;
-       ++i)
-    for (k = 0; k < tokensetsize; ++k)
-      lookaheadset[k] |= LA (i)[k];
+  for (i = 0; i < state->nlookaheads; ++i)
+    bitset_or (lookaheadset, lookaheadset, LA[state->lookaheadsp + i]);

 
 

-  for (k = 0; k < tokensetsize; ++k)
-    lookaheadset[k] &= shiftset[k];
+  bitset_and (lookaheadset, lookaheadset, shiftset);

 
 

-  for (i = 0; i < ntokens; i++)
-    if (BITISSET (lookaheadset, i))
-      src_count++;
+  src_count = bitset_count (lookaheadset);

 
   return src_count;
 }
 
   return src_count;
 }


@@ -260,23 +323,20 @@ count_sr_conflicts (int state)
 `----------------------------------------------*/
 
 static int
 `----------------------------------------------*/
 
 static int

-count_rr_conflicts (int state)
+count_rr_conflicts (state_t *state)

 {
   int i;
   int rrc_count = 0;
 
 {
   int i;
   int rrc_count = 0;
 

-  int m = state_table[state]->lookaheads;
-  int n = state_table[state + 1]->lookaheads;
-
-  if (n - m < 2)
+  if (state->nlookaheads < 2)

     return 0;
 
   for (i = 0; i < ntokens; i++)
     {
       int count = 0;
       int j;
     return 0;
 
   for (i = 0; i < ntokens; i++)
     {
       int count = 0;
       int j;

-      for (j = m; j < n; j++)
-       if (BITISSET (LA (m), j))
+      for (j = 0; j < state->nlookaheads; ++j)
+       if (bitset_test (LA[state->lookaheadsp + j], i))

          count++;
 
       if (count >= 2)
          count++;
 
       if (count >= 2)


@@ -333,13 +393,13 @@ void
 conflicts_output (FILE *out)
 {
   bool printed_sth = FALSE;
 conflicts_output (FILE *out)
 {
   bool printed_sth = FALSE;

-  int i;
+  size_t i;

   for (i = 0; i < nstates; i++)
     if (conflicts[i])
       {
        fprintf (out, _("State %d contains "), i);
   for (i = 0; i < nstates; i++)
     if (conflicts[i])
       {
        fprintf (out, _("State %d contains "), i);

-       fputs (conflict_report (count_sr_conflicts (i),
-                               count_rr_conflicts (i)), out);
+       fputs (conflict_report (count_sr_conflicts (states[i]),
+                               count_rr_conflicts (states[i])), out);

        printed_sth = TRUE;
       }
   if (printed_sth)
        printed_sth = TRUE;
       }
   if (printed_sth)


@@ -354,7 +414,7 @@ conflicts_output (FILE *out)
 void
 conflicts_print (void)
 {
 void
 conflicts_print (void)
 {

-  int i;
+  size_t 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
 
   /* 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


@@ -368,8 +428,8 @@ conflicts_print (void)
   for (i = 0; i < nstates; i++)
     if (conflicts[i])
       {
   for (i = 0; i < nstates; i++)
     if (conflicts[i])
       {

-       src_total += count_sr_conflicts (i);
-       rrc_total += count_rr_conflicts (i);
+       src_total += count_sr_conflicts (states[i]);
+       rrc_total += count_rr_conflicts (states[i]);

       }
 
   src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);
       }
 
   src_ok = src_total == (expected_conflicts == -1 ? 0 : expected_conflicts);


@@ -411,146 +471,10 @@ conflicts_print (void)
 
 
 void
 
 
 void

-print_reductions (FILE *out, int state)
-{
-  int i;
-  int j;
-  int m;
-  int n;
-  shifts *shiftp;
-  errs *errp;
-  int nodefault = 0;
-
-  for (i = 0; i < tokensetsize; i++)
-    shiftset[i] = 0;
-
-  shiftp = state_table[state]->shifts;
-  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
-    if (!SHIFT_IS_DISABLED (shiftp, i))
-      {
-       /* if this state has a shift for the error token, don't use a
-          default rule.  */
-       if (SHIFT_IS_ERROR (shiftp, i))
-         nodefault = 1;
-       SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
-      }
-
-  errp = state_table[state]->errs;
-  if (errp)
-    for (i = 0; i < errp->nerrs; i++)
-      if (errp->errs[i])
-       SETBIT (shiftset, errp->errs[i]);
-
-  m = state_table[state]->lookaheads;
-  n = state_table[state + 1]->lookaheads;
-
-  if (n - m == 1 && !nodefault)
-    {
-      int k;
-      int default_rule = LAruleno[m];
-
-      for (k = 0; k < tokensetsize; ++k)
-       lookaheadset[k] = LA (m)[k] & shiftset[k];
-
-      for (i = 0; i < ntokens; i++)
-       if (BITISSET (lookaheadset, i))
-         fprintf (out, _("    %-4s\t[reduce using rule %d (%s)]\n"),
-                  tags[i], default_rule,
-                  tags[rule_table[default_rule].lhs]);
-
-      fprintf (out, _("    $default\treduce using rule %d (%s)\n\n"),
-              default_rule, tags[rule_table[default_rule].lhs]);
-    }
-  else if (n - m >= 1)
-    {
-      int k;
-
-      int cmax = 0;
-      int default_LA = -1;
-      int default_rule = 0;
-
-      if (!nodefault)
-       for (i = m; i < n; i++)
-         {
-           int count = 0;
-
-           for (k = 0; k < tokensetsize; ++k)
-             lookaheadset[k] = LA (i)[k] & ~shiftset[k];
-
-           for (j = 0; j < ntokens; j++)
-             if (BITISSET (lookaheadset, j))
-               count++;
-
-           if (count > cmax)
-             {
-               cmax = count;
-               default_LA = i;
-               default_rule = LAruleno[i];
-             }
-
-           for (k = 0; k < tokensetsize; ++k)
-             shiftset[k] |= lookaheadset[k];
-         }
-
-      for (i = 0; i < tokensetsize; i++)
-       shiftset[i] = 0;
-
-      for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
-       if (!SHIFT_IS_DISABLED (shiftp, i))
-         SETBIT (shiftset, SHIFT_SYMBOL (shiftp, i));
-
-      for (i = 0; i < ntokens; i++)
-       {
-         int defaulted = 0;
-         int count = BITISSET (shiftset, i);
-
-         for (j = m; j < n; j++)
-           {
-             if (BITISSET (LA (m), j))
-               {
-                 if (count == 0)
-                   {
-                     if (j != default_LA)
-                       fprintf (out,
-                                _("    %-4s\treduce using rule %d (%s)\n"),
-                                tags[i],
-                                LAruleno[j],
-                                tags[rule_table[LAruleno[j]].lhs]);
-                     else
-                       defaulted = 1;
-
-                     count++;
-                   }
-                 else
-                   {
-                     if (defaulted)
-                       fprintf (out,
-                                _("    %-4s\treduce using rule %d (%s)\n"),
-                                tags[i],
-                                LAruleno[default_LA],
-                                tags[rule_table[LAruleno[default_LA]].lhs]);
-                     defaulted = 0;
-                     fprintf (out,
-                              _("    %-4s\t[reduce using rule %d (%s)]\n"),
-                              tags[i],
-                              LAruleno[j],
-                              tags[rule_table[LAruleno[j]].lhs]);
-                   }
-               }
-           }
-       }
-
-      if (default_LA >= 0)
-       fprintf (out, _("    $default\treduce using rule %d (%s)\n"),
-                default_rule, tags[rule_table[default_rule].lhs]);
-    }
-}
-
-
-void
-free_conflicts (void)
+conflicts_free (void)

 {
   XFREE (conflicts);
 {
   XFREE (conflicts);

-  XFREE (shiftset);
-  XFREE (lookaheadset);
+  bitset_free (shiftset);
+  bitset_free (lookaheadset);
+  obstack_free (&solved_conflicts_obstack, NULL);

 }
 }