X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/6e649e659ebc2d8b54fa4636986370b76c2ff988..c98b5143b071e351bdb820565681890046a6b45a:/src/tables.c

diff --git a/src/tables.c b/src/tables.c
index e1f0c61e..f06cba86 100644
--- a/src/tables.c
+++ b/src/tables.c
@@ -1,56 +1,65 @@
-/* Output the generated parsing program for bison,
-   Copyright (C) 1984, 1986, 1989, 1992, 2000, 2001, 2002
-   Free Software Foundation, Inc.
+/* Output the generated parsing program for Bison.
+
+   Copyright (C) 1984, 1986, 1989, 1992, 2000-2006, 2009-2013 Free
+   Software Foundation, Inc.
 
    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
-   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 "quotearg.h"
-#include "getargs.h"
+
+#include <bitsetv.h>
+
+#include "complain.h"
+#include "conflicts.h"
 #include "files.h"
+#include "getargs.h"
 #include "gram.h"
-#include "complain.h"
 #include "lalr.h"
+#include "muscle-tab.h"
 #include "reader.h"
 #include "symtab.h"
-#include "conflicts.h"
 #include "tables.h"
 
-/* Several tables will be indexed both by state and nonterminal
-   numbers.  We call `vector' such a thing (= either a state or a
-   symbol number.
+/* Several tables are indexed both by state and nonterminal numbers.
+   We call such an index a 'vector'; i.e., a vector is either a state
+   or a nonterminal number.
 
    Of course vector_number_t ought to be wide enough to contain
-   state_number_t and symbol_number_t.  */
-typedef short vector_number_t;
-#define VECTOR_NUMBER_MAX ((vector_number_t) SHRT_MAX)
-#define VECTOR_NUMBER_MIN ((vector_number_t) SHRT_MIN)
-#define state_number_to_vector_number(State) \
-   ((vector_number_t) State)
-#define symbol_number_to_vector_number(Symbol) \
-   ((vector_number_t) (state_number_as_int (nstates) + Symbol - ntokens))
+   state_number and symbol_number.  */
+typedef int vector_number;
+
+#if 0 /* Not currently used.  */
+static inline vector_number
+state_number_to_vector_number (state_number s)
+{
+  return s;
+}
+#endif
+
+static inline vector_number
+symbol_number_to_vector_number (symbol_number sym)
+{
+  return state_number_as_int (nstates) + sym - ntokens;
+}
 
 int nvectors;
 
 
-/* FROMS and TOS are indexed by vector_number_t.
+/* FROMS and TOS are indexed by vector_number.
 
    If VECTOR is a nonterminal, (FROMS[VECTOR], TOS[VECTOR]) form an
    array of state numbers of the non defaulted GOTO on VECTOR.
@@ -63,95 +72,96 @@ int nvectors;
    (FROMS[VECTOR][SIZE] - FROMS[VECTOR][0] + 1) where SIZE =
    TALLY[VECTOR].
 
-   FROMS therefore contains symbol_number_t and action_number_t,
-   TOS state_number_t and action_number_t,
+   FROMS therefore contains symbol_number and action_number,
+   TOS state_number and action_number,
    TALLY sizes,
    WIDTH differences of FROMS.
 
-   Let base_t be the type of FROMS, TOS, and WIDTH.  */
-#define BASE_MAX ((base_t) INT_MAX)
-#define BASE_MIN ((base_t) INT_MIN)
+   Let base_number be the type of FROMS, TOS, and WIDTH.  */
+#define BASE_MAXIMUM INT_MAX
+#define BASE_MINIMUM INT_MIN
 
-static base_t **froms = NULL;
-static base_t **tos = NULL;
-static unsigned int **conflict_tos = NULL;
-static short *tally = NULL;
-static base_t *width = NULL;
+static base_number **froms;
+static base_number **tos;
+static unsigned int **conflict_tos;
+static size_t *tally;
+static base_number *width;
 
 
 /* For a given state, N = ACTROW[SYMBOL]:
 
-   If N = 0, stands for `run the default action'.
-   If N = MIN, stands for `raise a syntax error'.
-   If N > 0, stands for `shift SYMBOL and go to n'.
-   If N < 0, stands for `reduce -N'.  */
-typedef short action_t;
-#define ACTION_MAX ((action_t) SHRT_MAX)
-#define ACTION_MIN ((action_t) SHRT_MIN)
+   If N = 0, stands for 'run the default action'.
+   If N = MIN, stands for 'raise a syntax error'.
+   If N > 0, stands for 'shift SYMBOL and go to n'.
+   If N < 0, stands for 'reduce -N'.  */
+typedef int action_number;
+#define ACTION_NUMBER_MINIMUM INT_MIN
 
-static action_t *actrow = NULL;
+static action_number *actrow;
 
 /* FROMS and TOS are reordered to be compressed.  ORDER[VECTOR] is the
-   new vector number of VECTOR.  We skip `empty' vectors (i.e.,
-   TALLY[VECTOR] = 0), and call these `entries'.  */
-static vector_number_t *order = NULL;
+   new vector number of VECTOR.  We skip 'empty' vectors (i.e.,
+   TALLY[VECTOR] = 0), and call these 'entries'.  */
+static vector_number *order;
 static int nentries;
 
-base_t *base = NULL;
+base_number *base = NULL;
 /* A distinguished value of BASE, negative infinite.  During the
-   computation equals to BASE_MIN, later mapped to BASE_NINF to
+   computation equals to BASE_MINIMUM, later mapped to BASE_NINF to
    keep parser tables small.  */
-base_t base_ninf = 0;
-static base_t *pos = NULL;
+base_number base_ninf = 0;
+static base_number *pos = NULL;
 
-static unsigned int *conflrow = NULL;
-unsigned int *conflict_table = NULL;
-unsigned int *conflict_list = NULL;
+static unsigned int *conflrow;
+unsigned int *conflict_table;
+unsigned int *conflict_list;
 int conflict_list_cnt;
 static int conflict_list_free;
 
 /* TABLE_SIZE is the allocated size of both TABLE and CHECK.  We start
    with more or less the original hard-coded value (which was
    SHRT_MAX).  */
-static size_t table_size = 32768;
-base_t *table = NULL;
-base_t *check = NULL;
+static int table_size = 32768;
+base_number *table;
+base_number *check;
 /* The value used in TABLE to denote explicit syntax errors
-   (%nonassoc), a negative infinite.  First defaults to ACTION_MIN,
+   (%nonassoc), a negative infinite.  First defaults to ACTION_NUMBER_MINIMUM,
    but in order to keep small tables, renumbered as TABLE_ERROR, which
    is the smallest (non error) value minus 1.  */
-base_t table_ninf = 0;
+base_number table_ninf = 0;
 static int lowzero;
 int high;
 
-state_number_t *yydefgoto;
-rule_number_t *yydefact;
+state_number *yydefgoto;
+rule_number *yydefact;
 
-/*----------------------------------------------------------------.
-| If TABLE (and CHECK) appear to be small to be addressed at      |
-| DESIRED, grow them.  Note that TABLE[DESIRED] is to be used, so |
-| the desired size is at least DESIRED + 1.                       |
-`----------------------------------------------------------------*/
+/*-------------------------------------------------------------------.
+| If TABLE, CONFLICT_TABLE, and CHECK are too small to be addressed  |
+| at DESIRED, grow them.  TABLE[DESIRED] can be used, so the desired |
+| size is at least DESIRED + 1.                                      |
+`-------------------------------------------------------------------*/
 
 static void
-table_grow (size_t desired)
+table_grow (int desired)
 {
-  size_t old_size = table_size;
+  int old_size = table_size;
 
   while (table_size <= desired)
     table_size *= 2;
 
   if (trace_flag & trace_resource)
     fprintf (stderr, "growing table and check from: %d to %d\n",
-	     old_size, table_size);
+             old_size, table_size);
 
-  table = XREALLOC (table, base_t, table_size);
-  check = XREALLOC (check, base_t, table_size);
-  conflict_table = XREALLOC (conflict_table, unsigned int, table_size);
+  table = xnrealloc (table, table_size, sizeof *table);
+  conflict_table = xnrealloc (conflict_table, table_size,
+                              sizeof *conflict_table);
+  check = xnrealloc (check, table_size, sizeof *check);
 
   for (/* Nothing. */; old_size < table_size; ++old_size)
     {
       table[old_size] = 0;
+      conflict_table[old_size] = 0;
       check[old_size] = -1;
     }
 }
@@ -160,58 +170,60 @@ table_grow (size_t desired)
 
 
 /*-------------------------------------------------------------------.
-| For GLR parsers, for each conflicted token in STATE, as indicated  |
-| 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 STATE.  Store the alternative |
-| reductions followed by a 0 in CONFLICT_LIST, updating		     |
+| For GLR parsers, for each conflicted token in S, as indicated      |
+| 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              |
 | CONFLICT_LIST_CNT, and storing an index to the start of the list   |
-| back into CONFLROW.						     |
+| back into CONFLROW.                                                |
 `-------------------------------------------------------------------*/
 
 static void
-conflict_row (state_t *state)
+conflict_row (state *s)
 {
   int i, j;
-  reductions_t *reds = state->reductions;
+  reductions *reds = s->reductions;
 
-  if (! glr_parser)
+  if (!nondeterministic_parser)
     return;
 
   for (j = 0; j < ntokens; j += 1)
     if (conflrow[j])
       {
-	conflrow[j] = conflict_list_cnt;
-
-	/* 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->lookaheads[i], j)
-	      && (actrow[j]
-		  != rule_number_as_item_number (reds->rules[i]->number)))
-	    {
-	      assert (conflict_list_free > 0);
-	      conflict_list[conflict_list_cnt] = reds->rules[i]->number + 1;
-	      conflict_list_cnt += 1;
-	      conflict_list_free -= 1;
-	    }
-
-	/* Leave a 0 at the end.  */
-	assert (conflict_list_free > 0);
-	conflict_list_cnt += 1;
-	conflict_list_free -= 1;
+        conflrow[j] = conflict_list_cnt;
+
+        /* 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->lookahead_tokens[i], j)
+              && (actrow[j]
+                  != rule_number_as_item_number (reds->rules[i]->number)))
+            {
+              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.  */
+        aver (0 < conflict_list_free);
+        conflict_list[conflict_list_cnt] = 0;
+        conflict_list_cnt += 1;
+        conflict_list_free -= 1;
       }
 }
 
 
 /*------------------------------------------------------------------.
-| Decide what to do for each type of token if seen as the lookahead |
-| token in specified state.  The value returned is used as the      |
+| Decide what to do for each type of token if seen 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       |
-| ACTION_MIN, a very negative number, means this situation is an    |
-| error.  The parser recognizes this value specially.               |
+| ACTION_NUMBER_MINIMUM, a very negative number, means this         |
+| situation is an error.  The parser recognizes this value          |
+| specially.                                                        |
 |                                                                   |
 | This is where conflicts are resolved.  The loop over lookahead    |
 | rules considered lower-numbered rules last, and the last rule     |
@@ -223,169 +235,181 @@ conflict_row (state_t *state)
 | that has any such conflicts.                                      |
 `------------------------------------------------------------------*/
 
-static rule_t *
-action_row (state_t *state)
+static rule *
+action_row (state *s)
 {
   int i;
-  rule_t *default_rule = NULL;
-  reductions_t *redp = state->reductions;
-  transitions_t *transitions = state->transitions;
-  errs_t *errp = state->errs;
+  rule *default_reduction = NULL;
+  reductions *reds = s->reductions;
+  transitions *trans = s->transitions;
+  errs *errp = s->errs;
   /* Set to nonzero to inhibit having any default reduction.  */
-  int nodefault = 0;
-  int conflicted = 0;
+  bool nodefault = false;
+  bool conflicted = false;
 
   for (i = 0; i < ntokens; i++)
     actrow[i] = conflrow[i] = 0;
 
-  if (redp->lookaheads)
+  if (reds->lookahead_tokens)
     {
       int j;
       bitset_iterator biter;
       /* loop over all the rules available here which require
-	 lookahead (in reverse order to give precedence to the first
-	 rule) */
-      for (i = redp->num - 1; i >= 0; --i)
-	/* and find each token which the rule finds acceptable
-	   to come next */
-	BITSET_FOR_EACH (biter, redp->lookaheads[i], j, 0)
-	{
-	  /* and record this rule as the rule to use if that
-	     token follows.  */
-	  if (actrow[j] != 0)
-	    conflicted = conflrow[j] = 1;
-	  actrow[j] = rule_number_as_item_number (redp->rules[i]->number);
-	}
+         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 */
+        BITSET_FOR_EACH (biter, reds->lookahead_tokens[i], j, 0)
+        {
+          /* and record this rule as the rule to use if that
+             token follows.  */
+          if (actrow[j] != 0)
+            {
+              conflicted = true;
+              conflrow[j] = 1;
+            }
+          actrow[j] = rule_number_as_item_number (reds->rules[i]->number);
+        }
     }
 
   /* Now see which tokens are allowed for shifts in this state.  For
      them, record the shift as the thing to do.  So shift is preferred
      to reduce.  */
-  FOR_EACH_SHIFT (transitions, i)
+  FOR_EACH_SHIFT (trans, i)
     {
-      symbol_number_t symbol = TRANSITION_SYMBOL (transitions, i);
-      state_t *shift_state = transitions->states[i];
+      symbol_number sym = TRANSITION_SYMBOL (trans, i);
+      state *shift_state = trans->states[i];
 
-      if (actrow[symbol] != 0)
-	conflicted = conflrow[symbol] = 1;
-      actrow[symbol] = state_number_as_int (shift_state->number);
+      if (actrow[sym] != 0)
+        {
+          conflicted = true;
+          conflrow[sym] = 1;
+        }
+      actrow[sym] = state_number_as_int (shift_state->number);
 
       /* Do not use any default reduction if there is a shift for
-	 error */
-      if (symbol == errtoken->number)
-	nodefault = 1;
+         error */
+      if (sym == errtoken->number)
+        nodefault = true;
     }
 
   /* See which tokens are an explicit error in this state (due to
-     %nonassoc).  For them, record ACTION_MIN as the action.  */
+     %nonassoc).  For them, record ACTION_NUMBER_MINIMUM as the
+     action.  */
   for (i = 0; i < errp->num; i++)
     {
-      symbol_t *symbol = errp->symbols[i];
-      actrow[symbol->number] = ACTION_MIN;
+      symbol *sym = errp->symbols[i];
+      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-reduction");
+    if (STRNEQ (default_reductions, "most") && !s->consistent)
+      nodefault = true;
+    free (default_reductions);
+  }
+
   /* Now find the most common reduction and make it the default action
      for this state.  */
 
-  if (redp->num >= 1 && !nodefault)
+  if (reds->num >= 1 && !nodefault)
     {
-      if (state->consistent)
-	default_rule = redp->rules[0];
+      if (s->consistent)
+        default_reduction = reds->rules[0];
       else
-	{
-	  int max = 0;
-	  for (i = 0; i < redp->num; i++)
-	    {
-	      int count = 0;
-	      rule_t *rule = redp->rules[i];
-	      symbol_number_t j;
-
-	      for (j = 0; j < ntokens; j++)
-		if (actrow[j] == rule_number_as_item_number (rule->number))
-		  count++;
-
-	      if (count > max)
-		{
-		  max = count;
-		  default_rule = rule;
-		}
-	    }
-
-	  /* GLR parsers need space for conflict lists, so we can't
-	     default conflicted entries.  For non-conflicted entries
-	     or as long as we are not building a GLR parser,
-	     actions that match the default are replaced with zero,
-	     which means "use the default". */
-
-	  if (max > 0)
-	    {
-	      int j;
-	      for (j = 0; j < ntokens; j++)
-		if (actrow[j] == rule_number_as_item_number (default_rule->number)
-		    && ! (glr_parser && conflrow[j]))
-		  actrow[j] = 0;
-	    }
-	}
+        {
+          int max = 0;
+          for (i = 0; i < reds->num; i++)
+            {
+              int count = 0;
+              rule *r = reds->rules[i];
+              symbol_number j;
+
+              for (j = 0; j < ntokens; j++)
+                if (actrow[j] == rule_number_as_item_number (r->number))
+                  count++;
+
+              if (count > max)
+                {
+                  max = count;
+                  default_reduction = r;
+                }
+            }
+
+          /* GLR parsers need space for conflict lists, so we can't
+             default conflicted entries.  For non-conflicted entries
+             or as long as we are not building a GLR parser,
+             actions that match the default are replaced with zero,
+             which means "use the default". */
+
+          if (max > 0)
+            {
+              int j;
+              for (j = 0; j < ntokens; j++)
+                if (actrow[j]
+                    == rule_number_as_item_number (default_reduction->number)
+                    && ! (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".  */
 
-  if (!default_rule)
+  if (!default_reduction)
     for (i = 0; i < ntokens; i++)
-      if (actrow[i] == ACTION_MIN)
-	actrow[i] = 0;
+      if (actrow[i] == ACTION_NUMBER_MINIMUM)
+        actrow[i] = 0;
 
   if (conflicted)
-    conflict_row (state);
+    conflict_row (s);
 
-  return default_rule;
+  return default_reduction;
 }
 
 
-/*--------------------------------------------.
-| Set FROMS, TOS, TALLY and WIDTH for STATE.  |
-`--------------------------------------------*/
+/*----------------------------------------.
+| Set FROMS, TOS, TALLY and WIDTH for S.  |
+`----------------------------------------*/
 
 static void
-save_row (state_number_t state)
+save_row (state_number s)
 {
-  symbol_number_t i;
-  int count;
-  base_t *sp = NULL;
-  base_t *sp1 = NULL;
-  base_t *sp2 = NULL;
-  unsigned int *sp3 = NULL;
-
-  /* Number of non default actions in STATE.  */
-  count = 0;
-  for (i = 0; i < ntokens; i++)
-    if (actrow[i] != 0)
-      count++;
-
-  if (count == 0)
-    return;
-
-  /* Allocate non defaulted actions.  */
-  froms[state] = sp1 = sp = XCALLOC (base_t, count);
-  tos[state] = sp2 = XCALLOC (base_t, count);
-  if (glr_parser)
-    conflict_tos[state] = sp3 = XCALLOC (unsigned int, count);
-  else
-    conflict_tos[state] = NULL;
+  symbol_number i;
 
-  /* Store non defaulted actions.  */
+  /* Number of non default actions in S.  */
+  size_t count = 0;
   for (i = 0; i < ntokens; i++)
     if (actrow[i] != 0)
-      {
-	*sp1++ = i;
-	*sp2++ = actrow[i];
-	if (glr_parser)
-	  *sp3++ = conflrow[i];
-      }
+      count++;
 
-  tally[state] = count;
-  width[state] = sp1[-1] - sp[0] + 1;
+  if (count)
+    {
+      /* Allocate non defaulted actions.  */
+      base_number *sp1 = froms[s] = xnmalloc (count, sizeof *sp1);
+      base_number *sp2 = tos[s] = xnmalloc (count, sizeof *sp2);
+      unsigned int *sp3 = conflict_tos[s] =
+        nondeterministic_parser ? xnmalloc (count, sizeof *sp3) : NULL;
+
+      /* Store non defaulted actions.  */
+      for (i = 0; i < ntokens; i++)
+        if (actrow[i] != 0)
+          {
+            *sp1++ = i;
+            *sp2++ = actrow[i];
+            if (nondeterministic_parser)
+              *sp3++ = conflrow[i];
+          }
+
+      tally[s] = count;
+      width[s] = sp1[-1] - froms[s][0] + 1;
+    }
 }
 
 
@@ -400,45 +424,47 @@ save_row (state_number_t state)
 static void
 token_actions (void)
 {
-  state_number_t i;
-  symbol_number_t j;
-  rule_number_t r;
+  int nconflict = nondeterministic_parser ? conflicts_total_count () : 0;
 
-  int nconflict = glr_parser ? conflicts_total_count () : 0;
+  yydefact = xnmalloc (nstates, sizeof *yydefact);
 
-  yydefact = XCALLOC (rule_number_t, nstates);
+  actrow = xnmalloc (ntokens, sizeof *actrow);
+  conflrow = xnmalloc (ntokens, sizeof *conflrow);
 
-  actrow = XCALLOC (action_t, ntokens);
-  conflrow = XCALLOC (unsigned int, ntokens);
-
-  conflict_list = XCALLOC (unsigned int, 1 + 2 * nconflict);
+  conflict_list = xnmalloc (1 + 2 * nconflict, sizeof *conflict_list);
   conflict_list_free = 2 * nconflict;
   conflict_list_cnt = 1;
 
   /* Find the rules which are reduced.  */
-  if (!glr_parser)
-    for (r = 0; r < nrules; ++r)
-      rules[r].useful = false;
-
-  for (i = 0; i < nstates; ++i)
+  if (!nondeterministic_parser)
     {
-      rule_t *default_rule = action_row (states[i]);
-      yydefact[i] = default_rule ? default_rule->number + 1 : 0;
-      save_row (i);
-
-      /* Now that the parser was computed, we can find which rules are
-	 really reduced, and which are not because of SR or RR
-	 conflicts.  */
-      if (!glr_parser)
-	{
-	  for (j = 0; j < ntokens; ++j)
-	    if (actrow[j] < 0 && actrow[j] != ACTION_MIN)
-	      rules[item_number_as_rule_number (actrow[j])].useful = true;
-	  if (yydefact[i])
-	    rules[yydefact[i] - 1].useful = true;
-	}
+      rule_number r;
+      for (r = 0; r < nrules; ++r)
+        rules[r].useful = false;
     }
 
+  {
+    state_number i;
+    for (i = 0; i < nstates; ++i)
+      {
+        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
+           really reduced, and which are not because of SR or RR
+           conflicts.  */
+        if (!nondeterministic_parser)
+          {
+            symbol_number j;
+            for (j = 0; j < ntokens; ++j)
+              if (actrow[j] < 0 && actrow[j] != ACTION_NUMBER_MINIMUM)
+                rules[item_number_as_rule_number (actrow[j])].useful = true;
+            if (yydefact[i])
+              rules[yydefact[i] - 1].useful = true;
+          }
+      }
+  }
   free (actrow);
   free (conflrow);
 }
@@ -447,82 +473,78 @@ token_actions (void)
 /*------------------------------------------------------------------.
 | Compute FROMS[VECTOR], TOS[VECTOR], TALLY[VECTOR], WIDTH[VECTOR], |
 | i.e., the information related to non defaulted GOTO on the nterm  |
-| SYMBOL.                                                           |
+| SYM.                                                              |
 |                                                                   |
-| DEFAULT_STATE is the principal destination on SYMBOL, i.e., the   |
-| default GOTO destination on SYMBOL.                               |
+| DEFAULT_STATE is the principal destination on SYM, i.e., the      |
+| default GOTO destination on SYM.                                  |
 `------------------------------------------------------------------*/
 
 static void
-save_column (symbol_number_t symbol, state_number_t default_state)
+save_column (symbol_number sym, state_number default_state)
 {
-  int i;
-  base_t *sp;
-  base_t *sp1;
-  base_t *sp2;
-  int count;
-  vector_number_t symno = symbol_number_to_vector_number (symbol);
-
-  goto_number_t begin = goto_map[symbol];
-  goto_number_t end = goto_map[symbol + 1];
+  goto_number i;
+  goto_number begin = goto_map[sym - ntokens];
+  goto_number end = goto_map[sym - ntokens + 1];
 
   /* Number of non default GOTO.  */
-  count = 0;
+  size_t count = 0;
   for (i = begin; i < end; i++)
     if (to_state[i] != default_state)
       count++;
 
-  if (count == 0)
-    return;
-
-  /* Allocate room for non defaulted gotos.  */
-  froms[symno] = sp1 = sp = XCALLOC (base_t, count);
-  tos[symno] = sp2 = XCALLOC (base_t, count);
-
-  /* Store the state numbers of the non defaulted gotos.  */
-  for (i = begin; i < end; i++)
-    if (to_state[i] != default_state)
-      {
-	*sp1++ = from_state[i];
-	*sp2++ = to_state[i];
-      }
-
-  tally[symno] = count;
-  width[symno] = sp1[-1] - sp[0] + 1;
+  if (count)
+    {
+      /* Allocate room for non defaulted gotos.  */
+      vector_number symno = symbol_number_to_vector_number (sym);
+      base_number *sp1 = froms[symno] = xnmalloc (count, sizeof *sp1);
+      base_number *sp2 = tos[symno] = xnmalloc (count, sizeof *sp2);
+
+      /* Store the state numbers of the non defaulted gotos.  */
+      for (i = begin; i < end; i++)
+        if (to_state[i] != default_state)
+          {
+            *sp1++ = from_state[i];
+            *sp2++ = to_state[i];
+          }
+
+      tally[symno] = count;
+      width[symno] = sp1[-1] - froms[symno][0] + 1;
+    }
 }
 
 
 /*----------------------------------------------------------------.
-| Return `the' most common destination GOTO on SYMBOL (a nterm).  |
+| The default state for SYM: the state which is 'the' most common |
+| GOTO destination on SYM (an nterm).                             |
 `----------------------------------------------------------------*/
 
-static state_number_t
-default_goto (symbol_number_t symbol, short state_count[])
+static state_number
+default_goto (symbol_number sym, size_t state_count[])
 {
-  state_number_t s;
-  int i;
-  goto_number_t m = goto_map[symbol];
-  goto_number_t n = goto_map[symbol + 1];
-  state_number_t default_state = (state_number_t) -1;
-  int max = 0;
-
-  if (m == n)
-    return (state_number_t) -1;
-
-  for (s = 0; s < nstates; s++)
-    state_count[s] = 0;
-
-  for (i = m; i < n; i++)
-    state_count[to_state[i]]++;
-
-  for (s = 0; s < nstates; s++)
-    if (state_count[s] > max)
-      {
-	max = state_count[s];
-	default_state = s;
-      }
+  goto_number begin = goto_map[sym - ntokens];
+  goto_number end = goto_map[sym - ntokens + 1];
+  state_number res = -1;
 
-  return default_state;
+  if (begin != end)
+    {
+      size_t max = 0;
+      goto_number i;
+      state_number s;
+
+      for (s = 0; s < nstates; s++)
+        state_count[s] = 0;
+
+      for (i = begin; i < end; i++)
+        state_count[to_state[i]]++;
+
+      for (s = 0; s < nstates; s++)
+        if (max < state_count[s])
+          {
+            max = state_count[s];
+            res = s;
+          }
+    }
+  return res;
 }
 
 
@@ -538,15 +560,15 @@ default_goto (symbol_number_t symbol, short state_count[])
 static void
 goto_actions (void)
 {
-  symbol_number_t i;
-  short *state_count = XCALLOC (short, nstates);
-  yydefgoto = XMALLOC (state_number_t, nvars);
+  symbol_number i;
+  size_t *state_count = xnmalloc (nstates, sizeof *state_count);
+  yydefgoto = xnmalloc (nvars, sizeof *yydefgoto);
 
   /* For a given nterm I, STATE_COUNT[S] is the number of times there
      is a GOTO to S on I.  */
   for (i = ntokens; i < nsyms; ++i)
     {
-      state_number_t default_state = default_goto (i, state_count);
+      state_number default_state = default_goto (i, state_count);
       save_column (i, default_state);
       yydefgoto[i - ntokens] = default_state;
     }
@@ -567,138 +589,136 @@ sort_actions (void)
   nentries = 0;
 
   for (i = 0; i < nvectors; i++)
-    if (tally[i] > 0)
+    if (0 < tally[i])
       {
-	int k;
-	int t = tally[i];
-	int w = width[i];
-	int j = nentries - 1;
+        int k;
+        size_t t = tally[i];
+        int w = width[i];
+        int j = nentries - 1;
 
-	while (j >= 0 && (width[order[j]] < w))
-	  j--;
+        while (0 <= j && width[order[j]] < w)
+          j--;
 
-	while (j >= 0 && (width[order[j]] == w) && (tally[order[j]] < t))
-	  j--;
+        while (0 <= j && width[order[j]] == w && tally[order[j]] < t)
+          j--;
 
-	for (k = nentries - 1; k > j; k--)
-	  order[k + 1] = order[k];
+        for (k = nentries - 1; k > j; k--)
+          order[k + 1] = order[k];
 
-	order[j + 1] = i;
-	nentries++;
+        order[j + 1] = i;
+        nentries++;
       }
 }
 
 
-/* If VECTOR is a state which actions (reflected by FROMS, TOS, TALLY
+/* If VECTOR is a state whose actions (reflected by FROMS, TOS, TALLY
    and WIDTH of VECTOR) are common to a previous state, return this
    state number.
 
    In any other case, return -1.  */
 
-static state_number_t
-matching_state (vector_number_t vector)
+static state_number
+matching_state (vector_number vector)
 {
-  vector_number_t i = order[vector];
-  int t;
-  int w;
-  int prev;
-
+  vector_number i = order[vector];
   /* If VECTOR is a nterm, return -1.  */
-  if (i >= (int) nstates)
-    return -1;
-
-  t = tally[i];
-  w = width[i];
-
-  /* If VECTOR has GLR conflicts, return -1 */
-  if (conflict_tos[i] != NULL)
-    {
-      int j;
-      for (j = 0; j < t; j += 1)
-	if (conflict_tos[i][j] != 0)
-	  return -1;
-    }
-
-  for (prev = vector - 1; prev >= 0; prev--)
+  if (i < nstates)
     {
-      vector_number_t j = order[prev];
-      int k;
-      int match = 1;
-
-      /* Given how ORDER was computed, if the WIDTH or TALLY is
-	 different, there cannot be a matching state.  */
-      if (width[j] != w || tally[j] != t)
-	return -1;
-
-      for (k = 0; match && k < t; k++)
-	if (tos[j][k] != tos[i][k] || froms[j][k] != froms[i][k]
-	    || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0))
-	  match = 0;
-
-      if (match)
-	return j;
+      size_t t = tally[i];
+      int w = width[i];
+      int prev;
+
+      /* If VECTOR has GLR conflicts, return -1 */
+      if (conflict_tos[i] != NULL)
+        {
+          int j;
+          for (j = 0; j < t; j += 1)
+            if (conflict_tos[i][j] != 0)
+              return -1;
+        }
+
+      for (prev = vector - 1; 0 <= prev; prev--)
+        {
+          vector_number j = order[prev];
+          /* Given how ORDER was computed, if the WIDTH or TALLY is
+             different, there cannot be a matching state.  */
+          if (width[j] != w || tally[j] != t)
+            return -1;
+          else
+            {
+              bool match = true;
+              int k;
+              for (k = 0; match && k < t; k++)
+                if (tos[j][k] != tos[i][k]
+                    || froms[j][k] != froms[i][k]
+                    || (conflict_tos[j] != NULL && conflict_tos[j][k] != 0))
+                  match = false;
+              if (match)
+                return j;
+            }
+        }
     }
-
   return -1;
 }
 
 
-static base_t
-pack_vector (vector_number_t vector)
+static base_number
+pack_vector (vector_number vector)
 {
-  vector_number_t i = order[vector];
-  int j;
-  int t = tally[i];
-  int loc = 0;
-  base_t *from = froms[i];
-  base_t *to = tos[i];
+  base_number res;
+  vector_number i = order[vector];
+  size_t t = tally[i];
+  base_number *from = froms[i];
+  base_number *to = tos[i];
   unsigned int *conflict_to = conflict_tos[i];
 
-  assert (t);
+  aver (t != 0);
 
-  for (j = lowzero - from[0]; j < (int) table_size; j++)
+  for (res = lowzero - from[0]; ; res++)
     {
-      int k;
-      int ok = 1;
-
-      for (k = 0; ok && k < t; k++)
-	{
-	  loc = j + state_number_as_int (from[k]);
-	  if (loc >= (int) table_size)
-	    table_grow (loc);
-
-	  if (table[loc] != 0)
-	    ok = 0;
-	}
-
-      for (k = 0; ok && k < vector; k++)
-	if (pos[k] == j)
-	  ok = 0;
+      bool ok = true;
+      aver (res < table_size);
+      {
+        int k;
+        for (k = 0; ok && k < t; k++)
+          {
+            int loc = res + state_number_as_int (from[k]);
+            if (table_size <= loc)
+              table_grow (loc);
+
+            if (table[loc] != 0)
+              ok = false;
+          }
+
+        if (ok)
+          for (k = 0; k < vector; k++)
+            if (pos[k] == res)
+              ok = false;
+      }
 
       if (ok)
-	{
-	  for (k = 0; k < t; k++)
-	    {
-	      loc = j + from[k];
-	      table[loc] = to[k];
-	      if (glr_parser && conflict_to != NULL)
-		conflict_table[loc] = conflict_to[k];
-	      check[loc] = from[k];
-	    }
-
-	  while (table[lowzero] != 0)
-	    lowzero++;
-
-	  if (loc > high)
-	    high = loc;
-
-	  assert (BASE_MIN <= j && j <= BASE_MAX);
-	  return j;
-	}
+        {
+          int loc;
+          int k;
+          for (k = 0; k < t; k++)
+            {
+              loc = res + state_number_as_int (from[k]);
+              table[loc] = to[k];
+              if (nondeterministic_parser && conflict_to != NULL)
+                conflict_table[loc] = conflict_to[k];
+              check[loc] = from[k];
+            }
+
+          while (table[lowzero] != 0)
+            lowzero++;
+
+          if (high < loc)
+            high = loc;
+
+          aver (BASE_MINIMUM <= res && res <= BASE_MAXIMUM);
+          return res;
+        }
     }
-#define pack_vector_succeeded 0
-  assert (pack_vector_succeeded);
-  return 0;
 }
 
 
@@ -710,11 +730,11 @@ pack_vector (vector_number_t vector)
 | parsers.                                                     |
 `-------------------------------------------------------------*/
 
-static base_t
-table_ninf_remap (base_t tab[], size_t size, base_t ninf)
+static base_number
+table_ninf_remap (base_number tab[], int size, base_number ninf)
 {
-  base_t res = 0;
-  size_t i;
+  base_number res = 0;
+  int i;
 
   for (i = 0; i < size; i++)
     if (tab[i] < res && tab[i] != ninf)
@@ -734,40 +754,40 @@ pack_table (void)
 {
   int i;
 
-  base = XCALLOC (base_t, nvectors);
-  pos = XCALLOC (base_t, nentries);
-  table = XCALLOC (base_t, table_size);
-  conflict_table = XCALLOC (unsigned int, table_size);
-  check = XCALLOC (base_t, table_size);
+  base = xnmalloc (nvectors, sizeof *base);
+  pos = xnmalloc (nentries, sizeof *pos);
+  table = xcalloc (table_size, sizeof *table);
+  conflict_table = xcalloc (table_size, sizeof *conflict_table);
+  check = xnmalloc (table_size, sizeof *check);
 
   lowzero = 0;
   high = 0;
 
   for (i = 0; i < nvectors; i++)
-    base[i] = BASE_MIN;
+    base[i] = BASE_MINIMUM;
 
-  for (i = 0; i < (int) table_size; i++)
+  for (i = 0; i < table_size; i++)
     check[i] = -1;
 
   for (i = 0; i < nentries; i++)
     {
-      state_number_t state = matching_state (i);
-      base_t place;
+      state_number s = matching_state (i);
+      base_number place;
 
-      if (state < 0)
-	/* A new set of state actions, or a nonterminal.  */
-	place = pack_vector (i);
+      if (s < 0)
+        /* A new set of state actions, or a nonterminal.  */
+        place = pack_vector (i);
       else
-	/* Action of I were already coded for STATE.  */
-	place = base[state];
+        /* Action of I were already coded for S.  */
+        place = base[s];
 
       pos[i] = place;
       base[order[i]] = place;
     }
 
   /* Use the greatest possible negative infinites.  */
-  base_ninf = table_ninf_remap (base, nvectors, BASE_MIN);
-  table_ninf = table_ninf_remap (table, high + 1, ACTION_MIN);
+  base_ninf = table_ninf_remap (base, nvectors, BASE_MINIMUM);
+  table_ninf = table_ninf_remap (table, high + 1, ACTION_NUMBER_MINIMUM);
 
   free (pos);
 }
@@ -784,28 +804,28 @@ tables_generate (void)
 {
   int i;
 
-  /* That's a poor way to make sure the sizes are properly corelated,
-     in particular the signedness is not taking into account, but it's
-     not useless.  */
-  assert (sizeof (nvectors) >= sizeof (nstates));
-  assert (sizeof (nvectors) >= sizeof (nvars));
+  /* 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 (sizeof nstates <= sizeof nvectors
+          && sizeof nvars <= sizeof nvectors);
 
   nvectors = state_number_as_int (nstates) + nvars;
 
-  froms = XCALLOC (base_t *, nvectors);
-  tos = XCALLOC (base_t *, nvectors);
-  conflict_tos = XCALLOC (unsigned int *, nvectors);
-  tally = XCALLOC (short, nvectors);
-  width = XCALLOC (base_t, nvectors);
+  froms = xcalloc (nvectors, sizeof *froms);
+  tos = xcalloc (nvectors, sizeof *tos);
+  conflict_tos = xcalloc (nvectors, sizeof *conflict_tos);
+  tally = xcalloc (nvectors, sizeof *tally);
+  width = xnmalloc (nvectors, sizeof *width);
 
   token_actions ();
 
   goto_actions ();
-  free (goto_map + ntokens);
+  free (goto_map);
   free (from_state);
   free (to_state);
 
-  order = XCALLOC (vector_number_t, nvectors);
+  order = xcalloc (nvectors, sizeof *order);
   sort_actions ();
   pack_table ();
   free (order);
@@ -817,7 +837,7 @@ tables_generate (void)
     {
       free (froms[i]);
       free (tos[i]);
-      XFREE (conflict_tos[i]);
+      free (conflict_tos[i]);
     }
 
   free (froms);