Version 2.4.1.

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 76f8145274ee6a08832a457834142224101fccc2..efda69fb35af83cc3e8fc8a0d9c1546a559d47ec 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,52 +1,53 @@
-/* Generate the nondeterministic finite state machine for bison,
+/* Generate the nondeterministic finite state machine for Bison.

 
 

-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002 Free Software
-   Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 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
+   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
    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.
+   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,
+   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
    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/>.  */

 
 
 /* See comments in state.h for the data structures that represent it.
    The entry point is generate_states.  */
 
 
 
 /* See comments in state.h for the data structures that represent it.
    The entry point is generate_states.  */
 

+#include <config.h>

 #include "system.h"
 #include "system.h"

-#include "bitset.h"
-#include "quotearg.h"
-#include "symtab.h"
-#include "gram.h"
+
+#include <bitset.h>
+#include <quotearg.h>
+
+#include "LR0.h"
+#include "closure.h"
+#include "complain.h"

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

-#include "reader.h"

 #include "gram.h"
 #include "gram.h"

-#include "state.h"
-#include "complain.h"
-#include "closure.h"
-#include "LR0.h"
+#include "gram.h"

 #include "lalr.h"
 #include "lalr.h"

+#include "reader.h"

 #include "reduce.h"
 #include "reduce.h"

+#include "state.h"
+#include "symtab.h"

 
 

-typedef struct state_list_s
+typedef struct state_list

 {
 {

-  struct state_list_s *next;
-  state_t *state;
-} state_list_t;
+  struct state_list *next;
+  state *state;
+} state_list;

 
 

-static state_list_t *first_state = NULL;
-static state_list_t *last_state = NULL;
+static state_list *first_state = NULL;
+static state_list *last_state = NULL;

 
 
 /*------------------------------------------------------------------.
 
 
 /*------------------------------------------------------------------.


@@ -54,24 +55,18 @@ static state_list_t *last_state = NULL;
 | later examination, in order to find its transitions.  Return it.  |
 `------------------------------------------------------------------*/
 
 | 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)
+static state *
+state_list_append (symbol_number sym, size_t core_size, item_number *core)

 {
 {

-  state_list_t *node = XMALLOC (state_list_t, 1);
-  state_t *state = state_new (symbol, core_size, core);
+  state_list *node = xmalloc (sizeof *node);
+  state *s = state_new (sym, core_size, core);

 
   if (trace_flag & trace_automaton)
 
   if (trace_flag & trace_automaton)

-    fprintf (stderr, _("state_list_append (state = %d, symbol = %d (%s))\n"),
-            nstates, symbol, symbols[symbol]->tag);
-
-  /* If this is the endtoken, and this is not the initial state, then
-     this is the final state.  */
-  if (symbol == 0 && first_state)
-    final_state = state;
+    fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",
+            nstates, sym, symbols[sym]->tag);

 
   node->next = NULL;
 
   node->next = NULL;

-  node->state = state;
+  node->state = s;

 
   if (!first_state)
     first_state = node;
 
   if (!first_state)
     first_state = node;


@@ -79,33 +74,34 @@ state_list_append (symbol_number_t symbol,
     last_state->next = node;
   last_state = node;
 
     last_state->next = node;
   last_state = node;
 

-  return state;
+  return s;

 }
 
 static int nshifts;
 }
 
 static int nshifts;

-static symbol_number_t *shift_symbol = NULL;
+static symbol_number *shift_symbol;

 
 

-static rule_t **redset = NULL;
-static state_t **shiftset = NULL;
+static rule **redset;
+static state **shiftset;

 
 

-static item_number_t **kernel_base = NULL;
-static int *kernel_size = NULL;
-static item_number_t *kernel_items = NULL;
+static item_number **kernel_base;
+static int *kernel_size;
+static item_number *kernel_items;

 
 \f
 static void
 allocate_itemsets (void)
 {
 
 \f
 static void
 allocate_itemsets (void)
 {

-  symbol_number_t i;
-  rule_number_t r;
-  item_number_t *rhsp;
+  symbol_number i;
+  rule_number r;
+  item_number *rhsp;

 
   /* Count the number of occurrences of all the symbols in RITEMS.
      Note that useless productions (hence useless nonterminals) are
      browsed too, hence we need to allocate room for _all_ the
      symbols.  */
 
   /* Count the number of occurrences of all the symbols in RITEMS.
      Note that useless productions (hence useless nonterminals) are
      browsed too, hence we need to allocate room for _all_ the
      symbols.  */

-  int count = 0;
-  short *symbol_count = XCALLOC (short, nsyms + nuseless_nonterminals);
+  size_t count = 0;
+  size_t *symbol_count = xcalloc (nsyms + nuseless_nonterminals,
+                                 sizeof *symbol_count);

 
   for (r = 0; r < nrules; ++r)
     for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)
 
   for (r = 0; r < nrules; ++r)
     for (rhsp = rules[r].rhs; *rhsp >= 0; ++rhsp)


@@ -116,13 +112,12 @@ allocate_itemsets (void)
 
   /* See comments before new_itemsets.  All the vectors of items
      live inside KERNEL_ITEMS.  The number of active items after
 
   /* See comments before new_itemsets.  All the vectors of items
      live inside KERNEL_ITEMS.  The number of active items after

-     some symbol cannot be more than the number of times that symbol
-     appears as an item, which is SYMBOL_COUNT[SYMBOL].
+     some symbol S cannot be more than the number of times that S
+     appears as an item, which is SYMBOL_COUNT[S].

      We allocate that much space for each symbol.  */
 
      We allocate that much space for each symbol.  */
 

-  kernel_base = XCALLOC (item_number_t *, nsyms);
-  if (count)
-    kernel_items = XCALLOC (item_number_t, count);
+  kernel_base = xnmalloc (nsyms, sizeof *kernel_base);
+  kernel_items = xnmalloc (count, sizeof *kernel_items);

 
   count = 0;
   for (i = 0; i < nsyms; i++)
 
   count = 0;
   for (i = 0; i < nsyms; i++)


@@ -132,7 +127,7 @@ allocate_itemsets (void)
     }
 
   free (symbol_count);
     }
 
   free (symbol_count);

-  kernel_size = XCALLOC (int, nsyms);
+  kernel_size = xnmalloc (nsyms, sizeof *kernel_size);

 }
 
 
 }
 
 


@@ -141,10 +136,10 @@ allocate_storage (void)
 {
   allocate_itemsets ();
 
 {
   allocate_itemsets ();
 

-  shiftset = XCALLOC (state_t *, nsyms);
-  redset = XCALLOC (rule_t *, nrules);
+  shiftset = xnmalloc (nsyms, sizeof *shiftset);
+  redset = xnmalloc (nrules, sizeof *redset);

   state_hash_new ();
   state_hash_new ();

-  shift_symbol = XCALLOC (symbol_number_t, nsyms);
+  shift_symbol = xnmalloc (nsyms, sizeof *shift_symbol);

 }
 
 
 }
 
 


@@ -156,7 +151,7 @@ free_storage (void)
   free (shiftset);
   free (kernel_base);
   free (kernel_size);
   free (shiftset);
   free (kernel_base);
   free (kernel_size);

-  XFREE (kernel_items);
+  free (kernel_items);

   state_hash_free ();
 }
 
   state_hash_free ();
 }
 


@@ -164,7 +159,7 @@ free_storage (void)
 
 
 /*---------------------------------------------------------------.
 
 
 /*---------------------------------------------------------------.

-| Find which symbols can be shifted in STATE, and for each one   |
+| Find which symbols can be shifted in S, and for each one       |

 | record which items would be active after that shift.  Uses the |
 | contents of itemset.                                           |
 |                                                                |
 | record which items would be active after that shift.  Uses the |
 | contents of itemset.                                           |
 |                                                                |


@@ -172,102 +167,96 @@ free_storage (void)
 | shifted.  For each symbol in the grammar, kernel_base[symbol]  |
 | points to a vector of item numbers activated if that symbol is |
 | shifted, and kernel_size[symbol] is their numbers.             |
 | shifted.  For each symbol in the grammar, kernel_base[symbol]  |
 | points to a vector of item numbers activated if that symbol is |
 | shifted, and kernel_size[symbol] is their numbers.             |

+|                                                                |
+| itemset is sorted on item index in ritem, which is sorted on   |
+| rule number.  Compute each kernel_base[symbol] with the same   |
+| sort.                                                          |

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

-new_itemsets (state_t *state)
+new_itemsets (state *s)

 {
 {

-  int i;
+  size_t i;

 
   if (trace_flag & trace_automaton)
 
   if (trace_flag & trace_automaton)

-    fprintf (stderr, _("Entering new_itemsets, state = %d\n"),
-            state->number);
+    fprintf (stderr, "Entering new_itemsets, state = %d\n", s->number);

 
 

-  for (i = 0; i < nsyms; i++)
-    kernel_size[i] = 0;
+  memset (kernel_size, 0, nsyms * sizeof *kernel_size);

 
   nshifts = 0;
 
 
   nshifts = 0;
 

-  for (i = 0; i < nritemset; ++i)
-    if (ritem[itemset[i]] >= 0)
+  for (i = 0; i < nitemset; ++i)
+    if (item_number_is_symbol_number (ritem[itemset[i]]))

       {
       {

-       symbol_number_t symbol
-         = item_number_as_symbol_number (ritem[itemset[i]]);
-       if (!kernel_size[symbol])
+       symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
+       if (!kernel_size[sym])

          {
          {

-           shift_symbol[nshifts] = symbol;
+           shift_symbol[nshifts] = sym;

            nshifts++;
          }
 
            nshifts++;
          }
 

-       kernel_base[symbol][kernel_size[symbol]] = itemset[i] + 1;
-       kernel_size[symbol]++;
+       kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
+       kernel_size[sym]++;

       }
 }
 
 
 
       }
 }
 
 
 

-/*-----------------------------------------------------------------.
-| Find the state we would get to (from the current state) by       |
-| shifting SYMBOL.  Create a new state if no equivalent one exists |
-| already.  Used by append_states.                                 |
-`-----------------------------------------------------------------*/
+/*--------------------------------------------------------------.
+| Find the state we would get to (from the current state) by    |
+| shifting SYM.  Create a new state if no equivalent one exists |
+| already.  Used by append_states.                              |
+`--------------------------------------------------------------*/

 
 

-static state_t *
-get_state (symbol_number_t symbol, size_t core_size, item_number_t *core)
+static state *
+get_state (symbol_number sym, size_t core_size, item_number *core)

 {
 {

-  state_t *sp;
+  state *s;

 
   if (trace_flag & trace_automaton)
 
   if (trace_flag & trace_automaton)

-    fprintf (stderr, _("Entering get_state, symbol = %d (%s)\n"),
-            symbol, symbols[symbol]->tag);
+    fprintf (stderr, "Entering get_state, symbol = %d (%s)\n",
+            sym, symbols[sym]->tag);

 
 

-  sp = state_hash_lookup (core_size, core);
-  if (!sp)
-    sp = state_list_append (symbol, core_size, core);
+  s = state_hash_lookup (core_size, core);
+  if (!s)
+    s = state_list_append (sym, core_size, core);

 
   if (trace_flag & trace_automaton)
 
   if (trace_flag & trace_automaton)

-    fprintf (stderr, _("Exiting get_state => %d\n"), sp->number);
+    fprintf (stderr, "Exiting get_state => %d\n", s->number);

 
 

-  return sp;
+  return s;

 }
 
 /*---------------------------------------------------------------.
 | Use the information computed by new_itemsets to find the state |
 }
 
 /*---------------------------------------------------------------.
 | Use the information computed by new_itemsets to find the state |

-| numbers reached by each shift transition from STATE.           |
+| numbers reached by each shift transition from S.              |

 |                                                                |
 | SHIFTSET is set up as a vector of those states.                |
 `---------------------------------------------------------------*/
 
 static void
 |                                                                |
 | SHIFTSET is set up as a vector of those states.                |
 `---------------------------------------------------------------*/
 
 static void

-append_states (state_t *state)
+append_states (state *s)

 {
   int i;
 {
   int i;

-  int j;
-  symbol_number_t symbol;

 
   if (trace_flag & trace_automaton)
 
   if (trace_flag & trace_automaton)

-    fprintf (stderr, _("Entering append_states, state = %d\n"),
-            state->number);
+    fprintf (stderr, "Entering append_states, state = %d\n", s->number);

 
 

-  /* first sort shift_symbol into increasing order */
+  /* First sort shift_symbol into increasing order.  */

 
   for (i = 1; i < nshifts; i++)
     {
 
   for (i = 1; i < nshifts; i++)
     {

-      symbol = shift_symbol[i];
-      j = i;
-      while (j > 0 && shift_symbol[j - 1] > symbol)
-       {
-         shift_symbol[j] = shift_symbol[j - 1];
-         j--;
-       }
-      shift_symbol[j] = symbol;
+      symbol_number sym = shift_symbol[i];
+      int j;
+      for (j = i; 0 < j && sym < shift_symbol[j - 1]; j--)
+       shift_symbol[j] = shift_symbol[j - 1];
+      shift_symbol[j] = sym;

     }
 
   for (i = 0; i < nshifts; i++)
     {
     }
 
   for (i = 0; i < nshifts; i++)
     {

-      symbol = shift_symbol[i];
-      shiftset[i] = get_state (symbol,
-                              kernel_size[symbol], kernel_base[symbol]);
+      symbol_number sym = shift_symbol[i];
+      shiftset[i] = get_state (sym, kernel_size[sym], kernel_base[sym]);

     }
 }
 
     }
 }
 


@@ -279,21 +268,30 @@ append_states (state_t *state)
 `----------------------------------------------------------------*/
 
 static void
 `----------------------------------------------------------------*/
 
 static void

-save_reductions (state_t *state)
+save_reductions (state *s)

 {
   int count = 0;
 {
   int count = 0;

-  int i;
+  size_t i;

 
   /* Find and count the active items that represent ends of rules. */
 
   /* Find and count the active items that represent ends of rules. */

-  for (i = 0; i < nritemset; ++i)
+  for (i = 0; i < nitemset; ++i)

     {
     {

-      int item = ritem[itemset[i]];
-      if (item < 0)
-       redset[count++] = &rules[item_number_as_rule_number (item)];
+      item_number item = ritem[itemset[i]];
+      if (item_number_is_rule_number (item))
+       {
+         rule_number r = item_number_as_rule_number (item);
+         redset[count++] = &rules[r];
+         if (r == 0)
+           {
+             /* This is "reduce 0", i.e., accept. */
+             aver (!final_state);
+             final_state = s;
+           }
+       }

     }
 
   /* Make a reductions structure and copy the data into it.  */
     }
 
   /* Make a reductions structure and copy the data into it.  */

-  state_reductions_set (state, count, redset);
+  state_reductions_set (s, count, redset);

 }
 
 \f
 }
 
 \f


@@ -304,23 +302,23 @@ save_reductions (state_t *state)
 static void
 set_states (void)
 {
 static void
 set_states (void)
 {

-  states = XCALLOC (state_t *, nstates);
+  states = xcalloc (nstates, sizeof *states);

 
   while (first_state)
     {
 
   while (first_state)
     {

-      state_list_t *this = first_state;
+      state_list *this = first_state;

 
       /* Pessimization, but simplification of the code: make sure all
         the states have valid transitions and reductions members,
         even if reduced to 0.  It is too soon for errs, which are
         computed later, but set_conflicts.  */
 
       /* Pessimization, but simplification of the code: make sure all
         the states have valid transitions and reductions members,
         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->transitions)
-       state_transitions_set (state, 0, 0);
-      if (!state->reductions)
-       state_reductions_set (state, 0, 0);
+      state *s = this->state;
+      if (!s->transitions)
+       state_transitions_set (s, 0, 0);
+      if (!s->reductions)
+       state_reductions_set (s, 0, 0);

 
 

-      states[state->number] = state;
+      states[s->number] = s;

 
       first_state = this->next;
       free (this);
 
       first_state = this->next;
       free (this);


@@ -338,44 +336,36 @@ set_states (void)
 void
 generate_states (void)
 {
 void
 generate_states (void)
 {

-  state_list_t *list = NULL;
+  item_number initial_core = 0;
+  state_list *list = NULL;

   allocate_storage ();
   new_closure (nritems);
 
   /* Create the initial state.  The 0 at the lhs is the index of the
      item of this initial rule.  */
   allocate_storage ();
   new_closure (nritems);
 
   /* 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;
+  state_list_append (0, 1, &initial_core);

 
 

-  while (list)
+  /* States are queued when they are created; process them all.  */
+  for (list = first_state; list; list = list->next)

     {
     {

-      state_t *state = list->state;
+      state *s = list->state;

       if (trace_flag & trace_automaton)
       if (trace_flag & trace_automaton)

-       fprintf (stderr, _("Processing state %d (reached by %s)\n"),
-                state->number,
-                symbols[state->accessing_symbol]->tag);
-      /* Set up ruleset and itemset for the transitions out of this
-         state.  ruleset gets a 1 bit for each rule that could reduce
-         now.  itemset gets a vector of all the items that could be
-         accepted next.  */
-      closure (state->items, state->nitems);
+       fprintf (stderr, "Processing state %d (reached by %s)\n",
+                s->number,
+                symbols[s->accessing_symbol]->tag);
+      /* Set up itemset for the transitions out of this state.  itemset gets a
+         vector of all the items that could be accepted next.  */
+      closure (s->items, s->nitems);

       /* Record the reductions allowed out of this state.  */
       /* Record the reductions allowed out of this state.  */

-      save_reductions (state);
+      save_reductions (s);

       /* Find the itemsets of the states that shifts can reach.  */
       /* Find the itemsets of the states that shifts can reach.  */

-      new_itemsets (state);
+      new_itemsets (s);

       /* Find or create the core structures for those states.  */
       /* Find or create the core structures for those states.  */

-      append_states (state);
+      append_states (s);

 
       /* Create the shifts structures for the shifts to those states,
         now that the state numbers transitioning to are known.  */
 
       /* Create the shifts structures for the shifts to those states,
         now that the state numbers transitioning to are known.  */

-      state_transitions_set (state, nshifts, shiftset);
-
-      /* States are queued when they are created; process them all.
-        */
-      list = list->next;
+      state_transitions_set (s, nshifts, shiftset);

     }
 
   /* discard various storage */
     }
 
   /* discard various storage */