Fix some memory leaks, and fix a bug: state 0 was examined twice.

* src/LR0.c (new_state): Merge into...
(state_list_append): this.
(new_states): Merge into...
(generate_states): here.
(set_states): Don't ensure a proper `errs' state member here, do it...
* src/conflicts.c (conflicts_solve): here.
* src/state.h, src/state.c: Comment changes.
(state_t): Rename member `shifts' as `transitions'.
Adjust all dependencies.
(errs_new): For consistency, also take the values as argument.
(errs_dup): Remove.
(state_errs_set): New.
(state_reductions_set, state_transitions_set): Assert that no
previous value was assigned.
(state_free): New.
(states_free): Use it.
* src/conflicts.c (resolve_sr_conflict): Don't use an `errs_t' as
temporary storage: use `errs' and `nerrs' as elsewhere.
(set_conflicts): Allocate and free this `errs'.

ChangeLog

@@ -1,3 +1,27 @@
+2002-07-03  Akim Demaille  <akim@epita.fr>
+
+	Fix some memory leaks, and fix a bug: state 0 was examined twice.
+
+	* src/LR0.c (new_state): Merge into...
+	(state_list_append): this.
+	(new_states): Merge into...
+	(generate_states): here.
+	(set_states): Don't ensure a proper `errs' state member here, do it...
+	* src/conflicts.c (conflicts_solve): here.
+	* src/state.h, src/state.c: Comment changes.
+	(state_t): Rename member `shifts' as `transitions'.
+	Adjust all dependencies.
+	(errs_new): For consistency, also take the values as argument.
+	(errs_dup): Remove.
+	(state_errs_set): New.
+	(state_reductions_set, state_transitions_set): Assert that no
+	previous value was assigned.
+	(state_free): New.
+	(states_free): Use it.
+	* src/conflicts.c (resolve_sr_conflict): Don't use an `errs_t' as
+	temporary storage: use `errs' and `nerrs' as elsewhere.
+	(set_conflicts): Allocate and free this `errs'.
+
 2002-07-02  Akim Demaille  <akim@epita.fr>
 
 	* lib/libiberty.h: New.

src/LR0.c

@@ -46,10 +46,28 @@ typedef struct state_list_s
 static state_list_t *first_state = NULL;
 static state_list_t *last_state = NULL;
 
-static void
+
-state_list_append (state_t *state)
+/*------------------------------------------------------------------.
+| A state was just discovered from another state.  Queue it for     |
+| later examination, in order to find its transitions.  Return it.  |
+`------------------------------------------------------------------*/
+
+static state_t *
+state_list_append (symbol_number_t symbol,
+		   size_t core_size, item_number_t *core)
 {
   state_list_t *node = XMALLOC (state_list_t, 1);
+  state_t *state = state_new (symbol, core_size, core);
+
+  if (trace_flag)
+    fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",
+	     nstates, symbol, symbols[symbol]->tag);
+
+  /* If this is the eoftoken, and this is not the initial state, then
+     this is the final state.  */
+  if (symbol == 0 && first_state)
+    final_state = state;
+
   node->next = NULL;
   node->state = state;
 
@@ -58,6 +76,8 @@ state_list_append (state_t *state)
   if (last_state)
     last_state->next = node;
   last_state = node;
+
+  return state;
 }
 
 static int nshifts;
@@ -184,33 +204,6 @@ new_itemsets (state_t *state)
 
 
 
-/*-----------------------------------------------------------------.
-| Subroutine of get_state.  Create a new state for those items, if |
-| necessary.                                                       |
-`-----------------------------------------------------------------*/
-
-static state_t *
-new_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
-{
-  state_t *res;
-
-  if (trace_flag)
-    fprintf (stderr, "Entering new_state, state = %d, symbol = %d (%s)\n",
-	     nstates, symbol, symbols[symbol]->tag);
-
-  res = state_new (symbol, core_size, core);
-  state_hash_insert (res);
-
-  /* If this is the eoftoken, and this is not the initial state, then
-     this is the final state.  */
-  if (symbol == 0 && first_state)
-    final_state = res;
-
-  state_list_append (res);
-  return res;
-}
-
-
 /*--------------------------------------------------------------.
 | Find the state number for the state we would get to (from the |
 | current state) by shifting symbol.  Create a new state if no  |
@@ -228,7 +221,7 @@ get_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
 
   sp = state_hash_lookup (core_size, core);
   if (!sp)
-    sp = new_state (symbol, core_size, core);
+    sp = state_list_append (symbol, core_size, core);
 
   if (trace_flag)
     fprintf (stderr, "Exiting get_state => %d\n", sp->number);
@@ -277,17 +270,6 @@ append_states (state_t *state)
 }
 
 
-static void
-new_states (void)
-{
-  /* The 0 at the lhs is the index of the item of this initial rule.  */
-  kernel_base[0][0] = 0;
-  kernel_size[0] = 1;
-  state_list_append (new_state (0, kernel_size[0], kernel_base[0]));
-}
-
-
-
 /*----------------------------------------------------------------.
 | Find which rules can be used for reduction transitions from the |
 | current state and make a reductions structure for the state to  |
@@ -332,13 +314,12 @@ set_states (void)
       state_list_t *this = first_state;
 
       /* Pessimization, but simplification of the code: make sure all
-	 the states have a shifts, errs, and reductions, even if
+	 the states have valid transitions and reductions members,
-	 reduced to 0.  */
+	 even if reduced to 0.  It is too soon for errs, which are
+	 computed later, but set_conflicts.  */
       state_t *state = this->state;
-      if (!state->shifts)
+      if (!state->transitions)
 	state_transitions_set (state, 0, 0);
-      if (!state->errs)
-	state->errs = errs_new (0);
       if (!state->reductions)
 	state_reductions_set (state, 0, 0);
 
@@ -363,7 +344,13 @@ generate_states (void)
   state_list_t *list = NULL;
   allocate_storage ();
   new_closure (nritems);
-  new_states ();
+
+  /* Create the initial state.  The 0 at the lhs is the index of the
+     item of this initial rule.  */
+  kernel_base[0][0] = 0;
+  kernel_size[0] = 1;
+  state_list_append (0, kernel_size[0], kernel_base[0]);
+
   list = first_state;
 
   while (list)

src/conflicts.c

@@ -139,7 +139,7 @@ log_resolution (rule_t *rule, symbol_number_t token,
 static void
 flush_shift (state_t *state, int token)
 {
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
   int i;
 
   bitset_reset (lookaheadset, token);
@@ -170,18 +170,20 @@ flush_reduce (bitset lookaheads, int token)
 | shift or reduce tables so that there is no longer a conflict.     |
 |                                                                   |
 | LOOKAHEAD is the number of the lookahead bitset to consider.      |
+|                                                                   |
+| ERRS can be used to store discovered explicit errors.             |
 `------------------------------------------------------------------*/
 
 static void
-resolve_sr_conflict (state_t *state, int lookahead)
+resolve_sr_conflict (state_t *state, int lookahead,
+		     symbol_number_t *errs)
 {
   symbol_number_t i;
   /* Find the rule to reduce by to get precedence of reduction.  */
   rule_t *redrule = state->lookaheads_rule[lookahead];
   int redprec = redrule->prec->prec;
   bitset lookaheads = state->lookaheads[lookahead];
-  errs_t *errp = errs_new (ntokens + 1);
+  int nerrs = 0;
-  errp->num = 0;
 
   for (i = 0; i < ntokens; i++)
     if (bitset_test (lookaheads, i)
@@ -224,7 +226,7 @@ resolve_sr_conflict (state_t *state, int lookahead)
 	      flush_shift (state, i);
 	      flush_reduce (lookaheads, i);
 	      /* Record an explicit error for this token.  */
-	      errp->symbols[errp->num++] = i;
+	      errs[nerrs++] = i;
 	      break;
 
 	    case undef_assoc:
@@ -235,8 +237,7 @@ resolve_sr_conflict (state_t *state, int lookahead)
 
   /* Some tokens have been explicitly made errors.  Allocate a
      permanent errs structure for this state, to record them.  */
-  state->errs = errs_dup (errp);
+  state_errs_set (state, nerrs, errs);
-  free (errp);
 
   if (obstack_object_size (&solved_conflicts_obstack))
     {
@@ -246,18 +247,24 @@ resolve_sr_conflict (state_t *state, int lookahead)
 }
 
 
+/*-------------------------------------------------------------------.
+| Solve the S/R conflicts of STATE using the                         |
+| precedence/associativity, and flag it inconsistent if it still has |
+| conflicts.  ERRS can be used as storage to compute the list of     |
+| lookaheads on which this STATE raises a parse error (%nonassoc).   |
+`-------------------------------------------------------------------*/
+
 static void
-set_conflicts (state_t *state)
+set_conflicts (state_t *state, symbol_number_t *errs)
 {
   int i;
-  transitions_t *transitions;
+  transitions_t *transitions = state->transitions;
 
   if (state->consistent)
     return;
 
   bitset_zero (lookaheadset);
 
-  transitions = state->shifts;
   for (i = 0; i < transitions->num && TRANSITION_IS_SHIFT (transitions, i); i++)
     if (!TRANSITION_IS_DISABLED (transitions, i))
       bitset_set (lookaheadset, TRANSITION_SYMBOL (transitions, i));
@@ -270,7 +277,7 @@ set_conflicts (state_t *state)
 	&& state->lookaheads_rule[i]->prec->prec
 	&& !bitset_disjoint_p (state->lookaheads[i], lookaheadset))
       {
-	resolve_sr_conflict (state, i);
+	resolve_sr_conflict (state, i, errs);
 	break;
       }
 
@@ -285,10 +292,18 @@ set_conflicts (state_t *state)
     }
 }
 
+
+/*----------------------------------------------------------------.
+| Solve all the S/R conflicts using the precedence/associativity, |
+| and flag as inconsistent the states that still have conflicts.  |
+`----------------------------------------------------------------*/
+
 void
 conflicts_solve (void)
 {
   state_number_t i;
+  /* List of lookaheads on which we explicitly raise a parse error.  */
+  symbol_number_t *errs = XMALLOC (symbol_number_t, ntokens + 1);
 
   conflicts = XCALLOC (char, nstates);
   shiftset = bitset_create (ntokens, BITSET_FIXED);
@@ -296,7 +311,16 @@ conflicts_solve (void)
   obstack_init (&solved_conflicts_obstack);
 
   for (i = 0; i < nstates; i++)
-    set_conflicts (states[i]);
+    {
+      set_conflicts (states[i], errs);
+
+      /* For uniformity of the code, make sure all the states have a valid
+	 `errs' member.  */
+      if (!states[i]->errs)
+	states[i]->errs = errs_new (0, 0);
+    }
+
+  free (errs);
 }
 
 
@@ -309,7 +333,7 @@ count_sr_conflicts (state_t *state)
 {
   int i;
   int src_count = 0;
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
 
   if (!transitions)
     return 0;

src/lalr.c

@@ -94,7 +94,7 @@ set_goto_map (void)
   ngotos = 0;
   for (state = 0; state < nstates; ++state)
     {
-      transitions_t *sp = states[state]->shifts;
+      transitions_t *sp = states[state]->transitions;
       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
 	{
@@ -127,7 +127,7 @@ set_goto_map (void)
 
   for (state = 0; state < nstates; ++state)
     {
-      transitions_t *sp = states[state]->shifts;
+      transitions_t *sp = states[state]->transitions;
       int i;
       for (i = sp->num - 1; i >= 0 && TRANSITION_IS_GOTO (sp, i); --i)
 	{
@@ -189,7 +189,7 @@ initialize_F (void)
   for (i = 0; i < ngotos; i++)
     {
       state_number_t stateno = to_state[i];
-      transitions_t *sp = states[stateno]->shifts;
+      transitions_t *sp = states[stateno]->transitions;
 
       int j;
       for (j = 0; j < sp->num && TRANSITION_IS_SHIFT (sp, j); j++)
@@ -266,8 +266,8 @@ build_relations (void)
 
 	  for (rp = rules[*rulep].rhs; *rp >= 0; rp++)
 	    {
-	      state = transitions_to (state->shifts,
+	      state = transitions_to (state->transitions,
-				 item_number_as_symbol_number (*rp));
+				      item_number_as_symbol_number (*rp));
 	      states1[length++] = state->number;
 	    }
 
@@ -360,7 +360,7 @@ states_lookaheads_count (void)
       int k;
       int nlookaheads = 0;
       reductions_t *rp = states[i]->reductions;
-      transitions_t *sp = states[i]->shifts;
+      transitions_t *sp = states[i]->transitions;
 
       /* We need a lookahead either to distinguish different
 	 reductions (i.e., there are two or more), or to distinguish a

src/output.c

@@ -430,7 +430,7 @@ action_row (state_t *state)
   int i;
   rule_number_t default_rule = 0;
   reductions_t *redp = state->reductions;
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
   errs_t *errp = state->errs;
   /* set nonzero to inhibit having any default reduction */
   int nodefault = 0;

src/print.c

@@ -125,7 +125,7 @@ print_core (FILE *out, state_t *state)
 static void
 print_transitions (state_t *state, FILE *out, bool display_transitions_p)
 {
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
   size_t width = 0;
   int i;
 
@@ -224,7 +224,7 @@ state_default_rule (state_t *state)
      we shift (S/R conflicts)...  */
   bitset_zero (shiftset);
   {
-    transitions_t *transitions = state->shifts;
+    transitions_t *transitions = state->transitions;
     for (i = 0; i < transitions->num && TRANSITION_IS_SHIFT (transitions, i); i++)
       if (!TRANSITION_IS_DISABLED (transitions, i))
 	{
@@ -302,7 +302,7 @@ print_reduction (FILE *out, size_t width,
 static void
 print_reductions (FILE *out, state_t *state)
 {
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
   reductions_t *redp = state->reductions;
   rule_t *default_rule = NULL;
   size_t width = 0;
@@ -396,7 +396,7 @@ static void
 print_actions (FILE *out, state_t *state)
 {
   reductions_t *redp = state->reductions;
-  transitions_t *transitions = state->shifts;
+  transitions_t *transitions = state->transitions;
 
   if (transitions->num == 0 && redp->num == 0)
     {

src/print_graph.c

@@ -125,7 +125,7 @@ print_actions (state_t *state, const char *node_name)
 {
   int i;
 
-  transitions_t     *transitions = state->shifts;
+  transitions_t     *transitions = state->transitions;
   reductions_t *redp = state->reductions;
 
   static char buff[10];

src/state.c

@@ -74,25 +74,17 @@ transitions_to (transitions_t *shifts, symbol_number_t s)
 | Create a new array of N errs.  |
 `-------------------------------*/
 
-#define ERRS_ALLOC(Nerrs)						\
+#define ERRS_ALLOC(Nerrs)				\
-  (errs_t *) xcalloc ((unsigned) (sizeof (errs_t)			\
+  (errs_t *) xcalloc ((sizeof (errs_t)			\
-                                  + (Nerrs - 1) * sizeof (symbol_number_t)), 1)
+                      + (Nerrs - 1) * sizeof (symbol_number_t)), 1)
 
 
 errs_t *
-errs_new (int n)
+errs_new (int num, symbol_number_t *tokens)
 {
-  errs_t *res = ERRS_ALLOC (n);
+  errs_t *res = ERRS_ALLOC (num);
-  res->num = n;
+  res->num = num;
-  return res;
+  memcpy (res->symbols, tokens, num * sizeof (tokens[0]));
-}
-
-
-errs_t *
-errs_dup (errs_t *src)
-{
-  errs_t *res = errs_new (src->num);
-  memcpy (res->symbols, src->symbols, src->num * sizeof (src->symbols[0]));
   return res;
 }
 
@@ -108,16 +100,16 @@ errs_dup (errs_t *src)
 | Create a new array of N reductions.  |
 `-------------------------------------*/
 
-#define REDUCTIONS_ALLOC(Nreductions)					\
+#define REDUCTIONS_ALLOC(Nreductions)				\
-  (reductions_t *) xcalloc ((unsigned) (sizeof (reductions_t)		\
+  (reductions_t *) xcalloc ((sizeof (reductions_t)		\
-                                  + (Nreductions - 1) * sizeof (rule_number_t)), 1)
+                            + (Nreductions - 1) * sizeof (rule_number_t)), 1)
 
 static reductions_t *
-reductions_new (int nreductions, short *reductions)
+reductions_new (int num, rule_number_t *reductions)
 {
-  reductions_t *res = REDUCTIONS_ALLOC (nreductions);
+  reductions_t *res = REDUCTIONS_ALLOC (num);
-  res->num = nreductions;
+  res->num = num;
-  memcpy (res->rules, reductions, nreductions * sizeof (reductions[0]));
+  memcpy (res->rules, reductions, num * sizeof (reductions[0]));
   return res;
 }
 
@@ -137,9 +129,10 @@ state_t *final_state = NULL;
   (state_t *) xcalloc ((unsigned) (sizeof (state_t) 			\
                                   + (Nitems - 1) * sizeof (item_number_t)), 1)
 
-/*------------------------------------------------------------.
+/*------------------------------------------------------------------.
-| Create a new state with ACCESSING_SYMBOL, for those items.  |
+| Create a new state with ACCESSING_SYMBOL, for those items.  Store |
-`------------------------------------------------------------*/
+| it in the state hash table.                                       |
+`------------------------------------------------------------------*/
 
 state_t *
 state_new (symbol_number_t accessing_symbol,
@@ -159,18 +152,35 @@ state_new (symbol_number_t accessing_symbol,
   res->nitems = core_size;
   memcpy (res->items, core, core_size * sizeof (core[0]));
 
+  state_hash_insert (res);
+
   return res;
 }
 
 
-/*--------------------------.
+/*-------------.
-| Set the shifts of STATE.  |
+| Free STATE.  |
-`--------------------------*/
+`-------------*/
+
+static void
+state_free (state_t *state)
+{
+  free (state->transitions);
+  free (state->reductions);
+  free (state->errs);
+  free (state);
+}
+
+
+/*-------------------------------.
+| Set the transitions of STATE.  |
+`-------------------------------*/
 
 void
-state_transitions_set (state_t *state, int nshifts, state_number_t *shifts)
+state_transitions_set (state_t *state, int num, state_number_t *transitions)
 {
-  state->shifts = transitions_new (nshifts, shifts);
+  assert (!state->transitions);
+  state->transitions = transitions_new (num, transitions);
 }
 
 
@@ -179,9 +189,22 @@ state_transitions_set (state_t *state, int nshifts, state_number_t *shifts)
 `------------------------------*/
 
 void
-state_reductions_set (state_t *state, int nreductions, short *reductions)
+state_reductions_set (state_t *state, int num, rule_number_t *reductions)
 {
-  state->reductions = reductions_new (nreductions, reductions);
+  assert (!state->reductions);
+  state->reductions = reductions_new (num, reductions);
+}
+
+
+/*------------------------.
+| Set the errs of STATE.  |
+`------------------------*/
+
+void
+state_errs_set (state_t *state, int num, symbol_number_t *tokens)
+{
+  assert (!state->errs);
+  state->errs = errs_new (num, tokens);
 }
 
 
@@ -322,13 +345,7 @@ void
 states_free (void)
 {
   state_number_t i;
-
   for (i = 0; i < nstates; ++i)
-    {
+    state_free (states[i]);
-      free (states[i]->shifts);
+  free (states);
-      XFREE (states[i]->reductions);
-      free (states[i]->errs);
-      free (states[i]);
-    }
-  XFREE (states);
 }

src/state.h

@@ -44,21 +44,21 @@
    Each core contains a vector of NITEMS items which are the indices
    in the RITEMS vector of the items that are selected in this state.
 
-   The two types of transitions are shifts (push the lookahead token
+   The two types of actions are shifts/gotos (push the lookahead token
-   and read another) and reductions (combine the last n things on the
+   and read another/goto to the state designated by a nterm) and
-   stack via a rule, replace them with the symbol that the rule
+   reductions (combine the last n things on the stack via a rule,
-   derives, and leave the lookahead token alone).  When the states are
+   replace them with the symbol that the rule derives, and leave the
-   generated, these transitions are represented in two other lists.
+   lookahead token alone).  When the states are generated, these
+   actions are represented in two other lists.
 
-   Each shifts structure describes the possible shift transitions out
+   Each transition_t structure describes the possible transitions out
-   of one state, the state whose number is in the number field.  The
+   of one state, the state whose number is in the number field.  Each
-   shifts structures are linked through next and first_shift points to
+   contains a vector of numbers of the states that transitions can go
-   them.  Each contains a vector of numbers of the states that shift
+   to.  The accessing_symbol fields of those states' cores say what
-   transitions can go to.  The accessing_symbol fields of those
+   kind of input leads to them.
-   states' cores say what kind of input leads to them.
 
-   A shift to state zero should be ignored.  Conflict resolution
+   A transition to state zero should be ignored: conflict resolution
-   deletes shifts by changing them to zero.
+   deletes transitions by having them point to zero.
 
    Each reductions structure describes the possible reductions at the
    state whose number is in the number field.  The data is a list of
@@ -68,18 +68,16 @@
    Conflict resolution can decide that certain tokens in certain
    states should explicitly be errors (for implementing %nonassoc).
    For each state, the tokens that are errors for this reason are
-   recorded in an errs structure, which has the state number in its
+   recorded in an errs structure, which holds the token numbers.
-   number field.  The rest of the errs structure is full of token
-   numbers.
 
-   There is at least one shift transition present in state zero.  It
+   There is at least one goto transition present in state zero.  It
    leads to a next-to-final state whose accessing_symbol is the
    grammar's start symbol.  The next-to-final state has one shift to
    the final state, whose accessing_symbol is zero (end of input).
-   The final state has one shift, which goes to the termination state
+   The final state has one shift, which goes to the termination state.
-   (whose number is nstates-1).  The reason for the extra state at the
+   The reason for the extra state at the end is to placate the
-   end is to placate the parser's strategy of making all decisions one
+   parser's strategy of making all decisions one token ahead of its
-   token ahead of its actions.  */
+   actions.  */
 
 #ifndef STATE_H_
 # define STATE_H_
@@ -108,36 +106,36 @@ typedef struct transtion_s
 } transitions_t;
 
 
-/* What is the symbol which is shifted by TRANSITIONS->states[Shift]?  Can
+/* What is the symbol labelling the transition to
-   be a token (amongst which the error token), or non terminals in
+   TRANSITIONS->states[Num]?  Can be a token (amongst which the error
-   case of gotos.  */
+   token), or non terminals in case of gotos.  */
 
-#define TRANSITION_SYMBOL(Transitions, Shift) \
+#define TRANSITION_SYMBOL(Transitions, Num) \
-  (states[Transitions->states[Shift]]->accessing_symbol)
+  (states[Transitions->states[Num]]->accessing_symbol)
 
-/* Is the TRANSITIONS->states[Shift] a real shift? (as opposed to gotos.) */
+/* Is the TRANSITIONS->states[Num] a shift? (as opposed to gotos).  */
 
-#define TRANSITION_IS_SHIFT(Transitions, Shift) \
+#define TRANSITION_IS_SHIFT(Transitions, Num) \
-  (ISTOKEN (TRANSITION_SYMBOL (Transitions, Shift)))
+  (ISTOKEN (TRANSITION_SYMBOL (Transitions, Num)))
 
-/* Is the TRANSITIONS->states[Shift] a goto?. */
+/* Is the TRANSITIONS->states[Num] a goto?. */
 
-#define TRANSITION_IS_GOTO(Transitions, Shift) \
+#define TRANSITION_IS_GOTO(Transitions, Num) \
-  (!TRANSITION_IS_SHIFT (Transitions, Shift))
+  (!TRANSITION_IS_SHIFT (Transitions, Num))
 
-/* Is the TRANSITIONS->states[Shift] then handling of the error token?. */
+/* Is the TRANSITIONS->states[Num] labelled by the error token?  */
 
-#define TRANSITION_IS_ERROR(Transitions, Shift) \
+#define TRANSITION_IS_ERROR(Transitions, Num) \
-  (TRANSITION_SYMBOL (Transitions, Shift) == errtoken->number)
+  (TRANSITION_SYMBOL (Transitions, Num) == errtoken->number)
 
 /* When resolving a SR conflicts, if the reduction wins, the shift is
    disabled.  */
 
-#define TRANSITION_DISABLE(Transitions, Shift) \
+#define TRANSITION_DISABLE(Transitions, Num) \
-  (Transitions->states[Shift] = 0)
+  (Transitions->states[Num] = 0)
 
-#define TRANSITION_IS_DISABLED(Transitions, Shift) \
+#define TRANSITION_IS_DISABLED(Transitions, Num) \
-  (Transitions->states[Shift] == 0)
+  (Transitions->states[Num] == 0)
 
 /* Return the state such these TRANSITIONS contain a shift/goto to it on
    SYMBOL.  Aborts if none found.  */
@@ -156,8 +154,7 @@ typedef struct errs_s
   symbol_number_t symbols[1];
 } errs_t;
 
-errs_t *errs_new PARAMS ((int n));
+errs_t *errs_new PARAMS ((int num, symbol_number_t *tokens));
-errs_t *errs_dup PARAMS ((errs_t *src));
 
 
 /*-------------.
@@ -180,7 +177,7 @@ typedef struct state_s
 {
   state_number_t number;
   symbol_number_t accessing_symbol;
-  transitions_t     *shifts;
+  transitions_t     *transitions;
   reductions_t *reductions;
   errs_t       *errs;
 
@@ -215,13 +212,17 @@ extern state_t *final_state;
 state_t *state_new PARAMS ((symbol_number_t accessing_symbol,
 			    size_t core_size, item_number_t *core));
 
-/* Set the shifts of STATE.  */
+/* Set the transitions of STATE.  */
 void state_transitions_set PARAMS ((state_t *state,
-			       int nshifts, state_number_t *shifts));
+				    int num, state_number_t *transitions));
 
 /* Set the reductions of STATE.  */
 void state_reductions_set PARAMS ((state_t *state,
-				   int nreductions, short *reductions));
+				   int num, rule_number_t *reductions));
+
+/* Set the errs of STATE.  */
+void state_errs_set PARAMS ((state_t *state,
+			     int num, symbol_number_t *errs));
 
 /* Print on OUT all the lookaheads such that this STATE wants to
    reduce this RULE.  */