Rename "default rule" to "default reduction".

[bison.git] / src / tables.c

diff --git a/src/tables.c b/src/tables.c
index c25d74e75f1a41483ef0b2312f2f561d42135348..06d6bab2d51e57a5d7bb23936ef6c123a0aa0007 100644 (file)
--- a/src/tables.c
+++ b/src/tables.c
@@ -1,26 +1,24 @@
 /* Output the generated parsing program for Bison.
 
    Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004,
 /* Output the generated parsing program for Bison.
 
    Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002, 2003, 2004,

-   2005 Free Software Foundation, Inc.
+   2005, 2006, 2009 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., 59 Temple Place - Suite 330, Boston, MA
-   02111-1307, USA.  */
-
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

 
 

+#include <config.h>

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


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

+#include "muscle-tab.h"

 #include "reader.h"
 #include "symtab.h"
 #include "tables.h"
 #include "reader.h"
 #include "symtab.h"
 #include "tables.h"


@@ -173,7 +172,7 @@ table_grow (int desired)
 
 /*-------------------------------------------------------------------.
 | For GLR parsers, for each conflicted token in S, as indicated      |
 
 /*-------------------------------------------------------------------.
 | For GLR parsers, for each conflicted token in S, as indicated      |

-| by non-zero entries in CONFLROW, create a list of possible        |
+| by non-zero entries in CONFLROW, create a list of possible        |

 | reductions that are alternatives to the shift or reduction        |
 | currently recorded for that token in S.  Store the alternative     |
 | reductions followed by a 0 in CONFLICT_LIST, updating                     |
 | reductions that are alternatives to the shift or reduction        |
 | currently recorded for that token in S.  Store the alternative     |
 | reductions followed by a 0 in CONFLICT_LIST, updating                     |


@@ -198,20 +197,18 @@ conflict_row (state *s)
        /* Find all reductions for token J, and record all that do not
           match ACTROW[J].  */
        for (i = 0; i < reds->num; i += 1)
        /* Find all reductions for token J, and record all that do not
           match ACTROW[J].  */
        for (i = 0; i < reds->num; i += 1)

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

              && (actrow[j]
                  != rule_number_as_item_number (reds->rules[i]->number)))
            {
              && (actrow[j]
                  != rule_number_as_item_number (reds->rules[i]->number)))
            {

-             if (conflict_list_free <= 0)
-               abort ();
+             aver (0 < conflict_list_free);

              conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1;
              conflict_list_cnt += 1;
              conflict_list_free -= 1;
            }
 
        /* Leave a 0 at the end.  */
              conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1;
              conflict_list_cnt += 1;
              conflict_list_free -= 1;
            }
 
        /* Leave a 0 at the end.  */

-       if (conflict_list_free <= 0)
-         abort ();
+       aver (0 < conflict_list_free);

        conflict_list[conflict_list_cnt] = 0;
        conflict_list_cnt += 1;
        conflict_list_free -= 1;
        conflict_list[conflict_list_cnt] = 0;
        conflict_list_cnt += 1;
        conflict_list_free -= 1;


@@ -221,7 +218,7 @@ conflict_row (state *s)
 
 /*------------------------------------------------------------------.
 | Decide what to do for each type of token if seen as the           |
 
 /*------------------------------------------------------------------.
 | Decide what to do for each type of token if seen as the           |

-| look-ahead in specified state.  The value returned is used as the |
+| lookahead in specified state.  The value returned is used as the  |

 | default action (yydefact) for the state.  In addition, ACTROW is  |
 | filled with what to do for each kind of token, index by symbol    |
 | number, with zero meaning do the default action.  The value       |
 | default action (yydefact) for the state.  In addition, ACTROW is  |
 | filled with what to do for each kind of token, index by symbol    |
 | number, with zero meaning do the default action.  The value       |


@@ -229,7 +226,7 @@ conflict_row (state *s)
 | situation is an error.  The parser recognizes this value         |
 | specially.                                                       |
 |                                                                   |
 | situation is an error.  The parser recognizes this value         |
 | specially.                                                       |
 |                                                                   |

-| This is where conflicts are resolved.  The loop over look-ahead   |
+| This is where conflicts are resolved.  The loop over lookahead    |

 | rules considered lower-numbered rules last, and the last rule     |
 | considered that likes a token gets to handle it.                  |
 |                                                                   |
 | rules considered lower-numbered rules last, and the last rule     |
 | considered that likes a token gets to handle it.                  |
 |                                                                   |


@@ -243,7 +240,7 @@ static rule *
 action_row (state *s)
 {
   int i;
 action_row (state *s)
 {
   int i;

-  rule *default_rule = NULL;
+  rule *default_reduction = NULL;

   reductions *reds = s->reductions;
   transitions *trans = s->transitions;
   errs *errp = s->errs;
   reductions *reds = s->reductions;
   transitions *trans = s->transitions;
   errs *errp = s->errs;


@@ -254,17 +251,17 @@ action_row (state *s)
   for (i = 0; i < ntokens; i++)
     actrow[i] = conflrow[i] = 0;
 
   for (i = 0; i < ntokens; i++)
     actrow[i] = conflrow[i] = 0;
 

-  if (reds->look_ahead_tokens)
+  if (reds->lookahead_tokens)

     {
       int j;
       bitset_iterator biter;
       /* loop over all the rules available here which require
     {
       int j;
       bitset_iterator biter;
       /* loop over all the rules available here which require

-        look-ahead (in reverse order to give precedence to the first
+        lookahead (in reverse order to give precedence to the first

         rule) */
       for (i = reds->num - 1; i >= 0; --i)
        /* and find each token which the rule finds acceptable
           to come next */
         rule) */
       for (i = reds->num - 1; i >= 0; --i)
        /* and find each token which the rule finds acceptable
           to come next */

-       BITSET_FOR_EACH (biter, reds->look_ahead_tokens[i], j, 0)
+       BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0)

        {
          /* and record this rule as the rule to use if that
             token follows.  */
        {
          /* and record this rule as the rule to use if that
             token follows.  */


@@ -307,13 +304,24 @@ action_row (state *s)
       actrow[sym->number] = ACTION_NUMBER_MINIMUM;
     }
 
       actrow[sym->number] = ACTION_NUMBER_MINIMUM;
     }
 

+  /* Turn off default reductions where requested by the user.  See
+     state_lookahead_tokens_count in lalr.c to understand when states are
+     labeled as consistent.  */
+  {
+    char *default_reductions =
+      muscle_percent_define_get ("lr.default_reductions");
+    if (0 != strcmp (default_reductions, "all") && !s->consistent)
+      nodefault = true;
+    free (default_reductions);
+  }
+

   /* Now find the most common reduction and make it the default action
      for this state.  */
 
   if (reds->num >= 1 && !nodefault)
     {
       if (s->consistent)
   /* Now find the most common reduction and make it the default action
      for this state.  */
 
   if (reds->num >= 1 && !nodefault)
     {
       if (s->consistent)

-       default_rule = reds->rules[0];
+       default_reduction = reds->rules[0];

       else
        {
          int max = 0;
       else
        {
          int max = 0;


@@ -330,7 +338,7 @@ action_row (state *s)
              if (count > max)
                {
                  max = count;
              if (count > max)
                {
                  max = count;

-                 default_rule = r;
+                 default_reduction = r;

                }
            }
 
                }
            }
 


@@ -344,17 +352,18 @@ action_row (state *s)
            {
              int j;
              for (j = 0; j < ntokens; j++)
            {
              int j;
              for (j = 0; j < ntokens; j++)

-               if (actrow[j] == rule_number_as_item_number (default_rule->number)
+               if (actrow[j]
+                    == rule_number_as_item_number (default_reduction->number)

                    && ! (nondeterministic_parser && conflrow[j]))
                  actrow[j] = 0;
            }
        }
     }
 
                    && ! (nondeterministic_parser && conflrow[j]))
                  actrow[j] = 0;
            }
        }
     }
 

-  /* If have no default rule, the default is an error.
+  /* If have no default reduction, the default is an error.

      So replace any action which says "error" with "use default".  */
 
      So replace any action which says "error" with "use default".  */
 

-  if (!default_rule)
+  if (!default_reduction)

     for (i = 0; i < ntokens; i++)
       if (actrow[i] == ACTION_NUMBER_MINIMUM)
        actrow[i] = 0;
     for (i = 0; i < ntokens; i++)
       if (actrow[i] == ACTION_NUMBER_MINIMUM)
        actrow[i] = 0;


@@ -362,7 +371,7 @@ action_row (state *s)
   if (conflicted)
     conflict_row (s);
 
   if (conflicted)
     conflict_row (s);
 

-  return default_rule;
+  return default_reduction;

 }
 
 
 }
 
 


@@ -412,7 +421,7 @@ save_row (state_number s)
 
 /*------------------------------------------------------------------.
 | Figure out the actions for the specified state, indexed by        |
 
 /*------------------------------------------------------------------.
 | Figure out the actions for the specified state, indexed by        |

-| look-ahead token type.                                            |
+| lookahead token type.                                             |

 |                                                                   |
 | The YYDEFACT table is output now.  The detailed info is saved for |
 | putting into YYTABLE later.                                       |
 |                                                                   |
 | The YYDEFACT table is output now.  The detailed info is saved for |
 | putting into YYTABLE later.                                       |


@@ -443,8 +452,8 @@ token_actions (void)
 
   for (i = 0; i < nstates; ++i)
     {
 
   for (i = 0; i < nstates; ++i)
     {

-      rule *default_rule = action_row (states[i]);
-      yydefact[i] = default_rule ? default_rule->number + 1 : 0;
+      rule *default_reduction = action_row (states[i]);
+      yydefact[i] = default_reduction ? default_reduction->number + 1 : 0;

       save_row (i);
 
       /* Now that the parser was computed, we can find which rules are
       save_row (i);
 
       /* Now that the parser was computed, we can find which rules are


@@ -675,16 +684,14 @@ pack_vector (vector_number vector)
   base_number *to = tos[i];
   unsigned int *conflict_to = conflict_tos[i];
 
   base_number *to = tos[i];
   unsigned int *conflict_to = conflict_tos[i];
 

-  if (!t)
-    abort ();
+  aver (t != 0);

 
   for (j = lowzero - from[0]; ; j++)
     {
       int k;
       bool ok = true;
 
 
   for (j = lowzero - from[0]; ; j++)
     {
       int k;
       bool ok = true;
 

-      if (table_size <= j)
-       abort ();
+      aver (j < table_size);

 
       for (k = 0; ok && k < t; k++)
        {
 
       for (k = 0; ok && k < t; k++)
        {


@@ -717,8 +724,7 @@ pack_vector (vector_number vector)
          if (loc > high)
            high = loc;
 
          if (loc > high)
            high = loc;
 

-         if (! (BASE_MINIMUM <= j && j <= BASE_MAXIMUM))
-           abort ();
+         aver (BASE_MINIMUM <= j && j <= BASE_MAXIMUM);

          return j;
        }
     }
          return j;
        }
     }


@@ -810,9 +816,8 @@ tables_generate (void)
   /* This is a poor way to make sure the sizes are properly
      correlated.  In particular the signedness is not taken into
      account.  But it's not useless.  */
   /* This is a poor way to make sure the sizes are properly
      correlated.  In particular the signedness is not taken into
      account.  But it's not useless.  */

-  verify (sizes_are_properly_correlated,
-         (sizeof nstates <= sizeof nvectors
-          && sizeof nvars <= sizeof nvectors));
+  verify (sizeof nstates <= sizeof nvectors
+         && sizeof nvars <= sizeof nvectors);

 
   nvectors = state_number_as_int (nstates) + nvars;
 
 
   nvectors = state_number_as_int (nstates) + nvars;