2007-11-08 Paolo Bonzini <bonzini@gnu.org>

[bison.git] / src / conflicts.c

diff --git a/src/conflicts.c b/src/conflicts.c
index 13121f6e290bc7f524de97943ed1668be0f3429a..9a02d4bb28dbdaf4880448e34d735978576aba19 100644 (file)
--- a/src/conflicts.c
+++ b/src/conflicts.c
@@ -1,24 +1,22 @@
-/* Find and resolve or report look-ahead conflicts for bison,
+/* Find and resolve or report lookahead conflicts for bison,

 
 

-   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989, 1992, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
+   2007 Free Software Foundation, Inc.

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

-   Bison is free software; you can redistribute it and/or modify it
-   under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.

 
 

-   Bison is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.

 
    You should have received a copy of the GNU General Public License
 
    You should have received a copy of the GNU General Public License

-   along with Bison; see the file COPYING.  If not, write to the Free
-   Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
-   02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 #include <config.h>
 #include "system.h"
 
 #include <config.h>
 #include "system.h"


@@ -32,6 +30,7 @@
 #include "getargs.h"
 #include "gram.h"
 #include "lalr.h"
 #include "getargs.h"
 #include "gram.h"
 #include "lalr.h"

+#include "print-xml.h"

 #include "reader.h"
 #include "state.h"
 #include "symtab.h"
 #include "reader.h"
 #include "state.h"
 #include "symtab.h"


@@ -41,9 +40,10 @@ int expected_sr_conflicts = -1;
 int expected_rr_conflicts = -1;
 static char *conflicts;
 static struct obstack solved_conflicts_obstack;
 int expected_rr_conflicts = -1;
 static char *conflicts;
 static struct obstack solved_conflicts_obstack;

+static struct obstack solved_conflicts_xml_obstack;

 
 static bitset shift_set;
 
 static bitset shift_set;

-static bitset look_ahead_set;
+static bitset lookahead_set;

 
 \f
 
 
 \f
 


@@ -74,23 +74,25 @@ log_resolution (rule *r, symbol_number token,
        case shift_resolution:
        case right_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,
        case shift_resolution:
        case right_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,

-                         _("\
-    Conflict between rule %d and token %s resolved as shift"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as shift"),

                          r->number,
                          symbols[token]->tag);
          break;
                          r->number,
                          symbols[token]->tag);
          break;

+

        case reduce_resolution:
        case left_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,
        case reduce_resolution:
        case left_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,

-                         _("\
-    Conflict between rule %d and token %s resolved as reduce"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as reduce"),

                          r->number,
                          symbols[token]->tag);
          break;
                          r->number,
                          symbols[token]->tag);
          break;

+

        case nonassoc_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,
        case nonassoc_resolution:
          obstack_fgrow2 (&solved_conflicts_obstack,

-                         _("\
-    Conflict between rule %d and token %s resolved as an error"),
+                         _("    Conflict between rule %d and token %s"
+                           " resolved as an error"),

                          r->number,
                          symbols[token]->tag);
          break;
                          r->number,
                          symbols[token]->tag);
          break;


@@ -124,13 +126,87 @@ log_resolution (rule *r, symbol_number token,
                          " (%%right %s)",
                          symbols[token]->tag);
          break;
                          " (%%right %s)",
                          symbols[token]->tag);
          break;

+

        case nonassoc_resolution:
          obstack_fgrow1 (&solved_conflicts_obstack,
                          " (%%nonassoc %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");
       obstack_sgrow (&solved_conflicts_obstack, ".\n");

+
+      /* XML report */
+      if (xml_flag)
+       {
+         /* The description of the resolution. */
+         switch (resolution)
+           {
+           case shift_resolution:
+           case right_resolution:
+             obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                             "        <resolution rule=\"%d\" symbol=\"%s\""
+                             " type=\"shift\">",
+                             r->number,
+                             xml_escape (symbols[token]->tag));
+             break;
+
+           case reduce_resolution:
+           case left_resolution:
+             obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                             "        <resolution rule=\"%d\" symbol=\"%s\""
+                             " type=\"reduce\">",
+                             r->number,
+                             xml_escape (symbols[token]->tag));
+             break;
+
+           case nonassoc_resolution:
+             obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                             "        <resolution rule=\"%d\" symbol=\"%s\""
+                             " type=\"error\">",
+                             r->number,
+                             xml_escape (symbols[token]->tag));
+             break;
+           }
+
+         /* The reason. */
+         switch (resolution)
+           {
+           case shift_resolution:
+             obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                             "%s &lt; %s",
+                             xml_escape_n (0, r->prec->tag),
+                             xml_escape_n (1, symbols[token]->tag));
+             break;
+
+           case reduce_resolution:
+             obstack_fgrow2 (&solved_conflicts_xml_obstack,
+                             "%s &lt; %s",
+                             xml_escape_n (0, symbols[token]->tag),
+                             xml_escape_n (1, r->prec->tag));
+             break;
+
+           case left_resolution:
+             obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                             "%%left %s",
+                             xml_escape (symbols[token]->tag));
+             break;
+
+           case right_resolution:
+             obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                             "%%right %s",
+                             xml_escape (symbols[token]->tag));
+             break;
+
+           case nonassoc_resolution:
+             obstack_fgrow1 (&solved_conflicts_xml_obstack,
+                             "%%nonassoc %s",
+                             xml_escape (symbols[token]->tag));
+         break;
+           }
+
+         obstack_sgrow (&solved_conflicts_xml_obstack, "</resolution>\n");
+       }

     }
 }
 
     }
 }
 


@@ -138,7 +214,7 @@ log_resolution (rule *r, symbol_number token,
 /*------------------------------------------------------------------.
 | Turn off the shift recorded for the specified token in the        |
 | specified state.  Used when we resolve a shift-reduce conflict in |
 /*------------------------------------------------------------------.
 | Turn off the shift recorded for the specified token in the        |
 | specified state.  Used when we resolve a shift-reduce conflict in |

-| favor of the reduction.                                           |
+| favor of the reduction or as an error (%nonassoc).                |

 `------------------------------------------------------------------*/
 
 static void
 `------------------------------------------------------------------*/
 
 static void


@@ -147,7 +223,7 @@ flush_shift (state *s, int token)
   transitions *trans = s->transitions;
   int i;
 
   transitions *trans = s->transitions;
   int i;
 

-  bitset_reset (look_ahead_set, token);
+  bitset_reset (lookahead_set, token);

   for (i = 0; i < trans->num; i++)
     if (!TRANSITION_IS_DISABLED (trans, i)
        && TRANSITION_SYMBOL (trans, i) == token)
   for (i = 0; i < trans->num; i++)
     if (!TRANSITION_IS_DISABLED (trans, i)
        && TRANSITION_SYMBOL (trans, i) == token)


@@ -156,15 +232,15 @@ flush_shift (state *s, int token)
 
 
 /*--------------------------------------------------------------------.
 
 
 /*--------------------------------------------------------------------.

-| Turn off the reduce recorded for the specified token for the        |
-| specified look-ahead.  Used when we resolve a shift-reduce conflict |
-| in favor of the shift.                                              |
+| Turn off the reduce recorded for the specified token in the         |
+| specified lookahead set.  Used when we resolve a shift-reduce       |
+| conflict in favor of the shift or as an error (%nonassoc).          |

 `--------------------------------------------------------------------*/
 
 static void
 `--------------------------------------------------------------------*/
 
 static void

-flush_reduce (bitset look_ahead_tokens, int token)
+flush_reduce (bitset lookahead_tokens, int token)

 {
 {

-  bitset_reset (look_ahead_tokens, token);
+  bitset_reset (lookahead_tokens, token);

 }
 
 
 }
 
 


@@ -174,25 +250,25 @@ flush_reduce (bitset look_ahead_tokens, int token)
 | rule has a precedence.  A conflict is resolved by modifying the   |
 | shift or reduce tables so that there is no longer a conflict.     |
 |                                                                   |
 | rule has a precedence.  A conflict is resolved by modifying the   |
 | shift or reduce tables so that there is no longer a conflict.     |
 |                                                                   |

-| RULENO is the number of the look-ahead bitset to consider.      |
+| RULENO is the number of the lookahead bitset to consider.         |

 |                                                                   |
 |                                                                   |

-| ERRORS can be used to store discovered explicit errors.           |
+| ERRORS and NERRS can be used to store discovered explicit         |
+| errors.                                                           |

 `------------------------------------------------------------------*/
 
 static void
 `------------------------------------------------------------------*/
 
 static void

-resolve_sr_conflict (state *s, int ruleno, symbol **errors)
+resolve_sr_conflict (state *s, int ruleno, symbol **errors, int *nerrs)

 {
   symbol_number i;
   reductions *reds = s->reductions;
   /* Find the rule to reduce by to get precedence of reduction.  */
   rule *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;
 {
   symbol_number i;
   reductions *reds = s->reductions;
   /* Find the rule to reduce by to get precedence of reduction.  */
   rule *redrule = reds->rules[ruleno];
   int redprec = redrule->prec->prec;

-  bitset look_ahead_tokens = reds->look_ahead_tokens[ruleno];
-  int nerrs = 0;
+  bitset lookahead_tokens = reds->lookahead_tokens[ruleno];

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

-    if (bitset_test (look_ahead_tokens, i)
-       && bitset_test (look_ahead_set, i)
+    if (bitset_test (lookahead_tokens, i)
+       && bitset_test (lookahead_set, i)

        && symbols[i]->prec)
       {
        /* Shift-reduce conflict occurs for token number i
        && symbols[i]->prec)
       {
        /* Shift-reduce conflict occurs for token number i


@@ -206,7 +282,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
        else if (symbols[i]->prec > redprec)
          {
            log_resolution (redrule, i, shift_resolution);
        else if (symbols[i]->prec > redprec)
          {
            log_resolution (redrule, i, shift_resolution);

-           flush_reduce (look_ahead_tokens, i);
+           flush_reduce (lookahead_tokens, i);

          }
        else
          /* Matching precedence levels.
          }
        else
          /* Matching precedence levels.


@@ -221,7 +297,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 
            case right_assoc:
              log_resolution (redrule, i, right_resolution);
 
            case right_assoc:
              log_resolution (redrule, i, right_resolution);

-             flush_reduce (look_ahead_tokens, i);
+             flush_reduce (lookahead_tokens, i);

              break;
 
            case left_assoc:
              break;
 
            case left_assoc:


@@ -232,25 +308,12 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
            case non_assoc:
              log_resolution (redrule, i, nonassoc_resolution);
              flush_shift (s, i);
            case non_assoc:
              log_resolution (redrule, i, nonassoc_resolution);
              flush_shift (s, i);

-             flush_reduce (look_ahead_tokens, i);
+             flush_reduce (lookahead_tokens, i);

              /* Record an explicit error for this token.  */
              /* Record an explicit error for this token.  */

-             errors[nerrs++] = symbols[i];
+             errors[(*nerrs)++] = symbols[i];

              break;
            }
       }
              break;
            }
       }

-
-  if (nerrs)
-    {
-      /* Some tokens have been explicitly made errors.  Allocate a
-        permanent errs structure for this state, to record them.  */
-      state_errs_set (s, nerrs, errors);
-    }
-
-  if (obstack_object_size (&solved_conflicts_obstack))
-    {
-      obstack_1grow (&solved_conflicts_obstack, '\0');
-      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
-    }

 }
 
 
 }
 
 


@@ -258,7 +321,7 @@ resolve_sr_conflict (state *s, int ruleno, symbol **errors)
 | 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   |
 | Solve the S/R conflicts of state S using the                       |
 | precedence/associativity, and flag it inconsistent if it still has |
 | conflicts.  ERRORS can be used as storage to compute the list of   |

-| look-ahead tokens on which S raises a syntax error (%nonassoc).    |
+| lookahead tokens on which S raises a syntax error (%nonassoc).     |

 `-------------------------------------------------------------------*/
 
 static void
 `-------------------------------------------------------------------*/
 
 static void


@@ -267,31 +330,48 @@ set_conflicts (state *s, symbol **errors)
   int i;
   transitions *trans = s->transitions;
   reductions *reds = s->reductions;
   int i;
   transitions *trans = s->transitions;
   reductions *reds = s->reductions;

+  int nerrs = 0;

 
   if (s->consistent)
     return;
 
 
   if (s->consistent)
     return;
 

-  bitset_zero (look_ahead_set);
+  bitset_zero (lookahead_set);

 
   FOR_EACH_SHIFT (trans, i)
 
   FOR_EACH_SHIFT (trans, i)

-    bitset_set (look_ahead_set, TRANSITION_SYMBOL (trans, i));
+    bitset_set (lookahead_set, TRANSITION_SYMBOL (trans, i));

 
 

-  /* Loop over all rules which require look-ahead in this state.  First
+  /* Loop over all rules which require lookahead in this state.  First

      check for shift-reduce conflict, and try to resolve using
      precedence.  */
   for (i = 0; i < reds->num; ++i)
     if (reds->rules[i]->prec && reds->rules[i]->prec->prec
      check for shift-reduce conflict, and try to resolve using
      precedence.  */
   for (i = 0; i < reds->num; ++i)
     if (reds->rules[i]->prec && reds->rules[i]->prec->prec

-       && !bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
-      resolve_sr_conflict (s, i, errors);
+       && !bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))
+      resolve_sr_conflict (s, i, errors, &nerrs);
+
+  if (nerrs)
+    {
+      /* Some tokens have been explicitly made errors.  Allocate a
+         permanent errs structure for this state, to record them.  */
+      state_errs_set (s, nerrs, errors);
+    }
+  if (obstack_object_size (&solved_conflicts_obstack))
+    {
+      obstack_1grow (&solved_conflicts_obstack, '\0');
+      s->solved_conflicts = obstack_finish (&solved_conflicts_obstack);
+    }
+  if (obstack_object_size (&solved_conflicts_xml_obstack))
+    {
+      obstack_1grow (&solved_conflicts_xml_obstack, '\0');
+      s->solved_conflicts_xml = obstack_finish (&solved_conflicts_xml_obstack);
+    }

 
 

-  /* Loop over all rules which require look-ahead in this state.  Check
+  /* Loop over all rules which require lookahead in this state.  Check

      for conflicts not resolved above.  */
   for (i = 0; i < reds->num; ++i)
     {
      for conflicts not resolved above.  */
   for (i = 0; i < reds->num; ++i)
     {

-      if (!bitset_disjoint_p (reds->look_ahead_tokens[i], look_ahead_set))
+      if (!bitset_disjoint_p (reds->lookahead_tokens[i], lookahead_set))

        conflicts[s->number] = 1;
        conflicts[s->number] = 1;

-
-      bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+      bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);

     }
 }
 
     }
 }
 


@@ -305,13 +385,14 @@ void
 conflicts_solve (void)
 {
   state_number i;
 conflicts_solve (void)
 {
   state_number i;

-  /* List of look-ahead tokens on which we explicitly raise a syntax error.  */
+  /* List of lookahead tokens on which we explicitly raise a syntax error.  */

   symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
 
   conflicts = xcalloc (nstates, sizeof *conflicts);
   shift_set = bitset_create (ntokens, BITSET_FIXED);
   symbol **errors = xnmalloc (ntokens + 1, sizeof *errors);
 
   conflicts = xcalloc (nstates, sizeof *conflicts);
   shift_set = bitset_create (ntokens, BITSET_FIXED);

-  look_ahead_set = bitset_create (ntokens, BITSET_FIXED);
+  lookahead_set = bitset_create (ntokens, BITSET_FIXED);

   obstack_init (&solved_conflicts_obstack);
   obstack_init (&solved_conflicts_obstack);

+  obstack_init (&solved_conflicts_xml_obstack);

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


@@ -327,6 +408,17 @@ conflicts_solve (void)
 }
 
 
 }
 
 

+void
+conflicts_update_state_numbers (state_number old_to_new[],
+                                state_number nstates_old)
+{
+  state_number i;
+  for (i = 0; i < nstates_old; ++i)
+    if (old_to_new[i] != nstates_old)
+      conflicts[old_to_new[i]] = conflicts[i];
+}
+
+

 /*---------------------------------------------.
 | Count the number of shift/reduce conflicts.  |
 `---------------------------------------------*/
 /*---------------------------------------------.
 | Count the number of shift/reduce conflicts.  |
 `---------------------------------------------*/


@@ -342,18 +434,18 @@ count_sr_conflicts (state *s)
   if (!trans)
     return 0;
 
   if (!trans)
     return 0;
 

-  bitset_zero (look_ahead_set);
+  bitset_zero (lookahead_set);

   bitset_zero (shift_set);
 
   FOR_EACH_SHIFT (trans, i)
     bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
 
   for (i = 0; i < reds->num; ++i)
   bitset_zero (shift_set);
 
   FOR_EACH_SHIFT (trans, i)
     bitset_set (shift_set, TRANSITION_SYMBOL (trans, i));
 
   for (i = 0; i < reds->num; ++i)

-    bitset_or (look_ahead_set, look_ahead_set, reds->look_ahead_tokens[i]);
+    bitset_or (lookahead_set, lookahead_set, reds->lookahead_tokens[i]);

 
 

-  bitset_and (look_ahead_set, look_ahead_set, shift_set);
+  bitset_and (lookahead_set, lookahead_set, shift_set);

 
 

-  src_count = bitset_count (look_ahead_set);
+  src_count = bitset_count (lookahead_set);

 
   return src_count;
 }
 
   return src_count;
 }


@@ -378,7 +470,7 @@ count_rr_conflicts (state *s, bool one_per_token)
       int count = 0;
       int j;
       for (j = 0; j < reds->num; ++j)
       int count = 0;
       int j;
       for (j = 0; j < reds->num; ++j)

-       if (bitset_test (reds->look_ahead_tokens[j], i))
+       if (bitset_test (reds->lookahead_tokens[j], i))

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


@@ -433,7 +525,7 @@ conflicts_output (FILE *out)
 /*--------------------------------------------------------.
 | Total the number of S/R and R/R conflicts.  Unlike the  |
 | code in conflicts_output, however, count EACH pair of   |
 /*--------------------------------------------------------.
 | Total the number of S/R and R/R conflicts.  Unlike the  |
 | code in conflicts_output, however, count EACH pair of   |

-| reductions for the same state and look-ahead as one     |
+| reductions for the same state and lookahead as one      |

 | conflict.                                              |
 `--------------------------------------------------------*/
 
 | conflict.                                              |
 `--------------------------------------------------------*/
 


@@ -530,6 +622,7 @@ conflicts_free (void)
 {
   free (conflicts);
   bitset_free (shift_set);
 {
   free (conflicts);
   bitset_free (shift_set);

-  bitset_free (look_ahead_set);
+  bitset_free (lookahead_set);

   obstack_free (&solved_conflicts_obstack, NULL);
   obstack_free (&solved_conflicts_obstack, NULL);

+  obstack_free (&solved_conflicts_xml_obstack, NULL);

 }
 }