doc: improve html and pdf rendering

[bison.git] / src / LR0.c

diff --git a/src/LR0.c b/src/LR0.c
index 945d41f8e0e8fc8ac35a1deeb2ad7e769f779bbf..c8f0166b11b4da34810b314416520d3b3e81a2e9 100644 (file)
--- a/src/LR0.c
+++ b/src/LR0.c
@@ -1,24 +1,22 @@
-/* Generate the nondeterministic finite state machine for Bison.
+/* Generate the LR(0) parser states for Bison.

 
 

-   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002, 2004, 2005, 2006
-   Free Software Foundation, Inc.
+   Copyright (C) 1984, 1986, 1989, 2000-2002, 2004-2015 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., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, 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.
 
 
 /* See comments in state.h for the data structures that represent it.


@@ -28,14 +26,12 @@
 #include "system.h"
 
 #include <bitset.h>
 #include "system.h"
 
 #include <bitset.h>

-#include <quotearg.h>

 
 #include "LR0.h"
 #include "closure.h"
 #include "complain.h"
 #include "getargs.h"
 #include "gram.h"
 
 #include "LR0.h"
 #include "closure.h"
 #include "complain.h"
 #include "getargs.h"
 #include "gram.h"

-#include "gram.h"

 #include "lalr.h"
 #include "reader.h"
 #include "reduce.h"
 #include "lalr.h"
 #include "reader.h"
 #include "reduce.h"


@@ -65,7 +61,7 @@ state_list_append (symbol_number sym, size_t core_size, item_number *core)
 
   if (trace_flag & trace_automaton)
     fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",
 
   if (trace_flag & trace_automaton)
     fprintf (stderr, "state_list_append (state = %d, symbol = %d (%s))\n",

-            nstates, sym, symbols[sym]->tag);
+             nstates, sym, symbols[sym]->tag);

 
   node->next = NULL;
   node->state = s;
 
   node->next = NULL;
   node->state = s;


@@ -103,13 +99,13 @@ allocate_itemsets (void)
      symbols.  */
   size_t count = 0;
   size_t *symbol_count = xcalloc (nsyms + nuseless_nonterminals,
      symbols.  */
   size_t count = 0;
   size_t *symbol_count = xcalloc (nsyms + nuseless_nonterminals,

-                                 sizeof *symbol_count);
+                                  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)
       {

-       count++;
-       symbol_count[*rhsp]++;
+        count++;
+        symbol_count[*rhsp]++;

       }
 
   /* See comments before new_itemsets.  All the vectors of items
       }
 
   /* See comments before new_itemsets.  All the vectors of items


@@ -169,6 +165,10 @@ 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


@@ -183,18 +183,18 @@ new_itemsets (state *s)
 
   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 sym = item_number_as_symbol_number (ritem[itemset[i]]);
-       if (!kernel_size[sym])
-         {
-           shift_symbol[nshifts] = sym;
-           nshifts++;
-         }
-
-       kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
-       kernel_size[sym]++;
+        symbol_number sym = item_number_as_symbol_number (ritem[itemset[i]]);
+        if (!kernel_size[sym])
+          {
+            shift_symbol[nshifts] = sym;
+            nshifts++;
+          }
+
+        kernel_base[sym][kernel_size[sym]] = itemset[i] + 1;
+        kernel_size[sym]++;

       }
 }
 
       }
 }
 


@@ -213,7 +213,7 @@ get_state (symbol_number sym, size_t core_size, item_number *core)
 
   if (trace_flag & trace_automaton)
     fprintf (stderr, "Entering get_state, symbol = %d (%s)\n",
 
   if (trace_flag & trace_automaton)
     fprintf (stderr, "Entering get_state, symbol = %d (%s)\n",

-            sym, symbols[sym]->tag);
+             sym, symbols[sym]->tag);

 
   s = state_hash_lookup (core_size, core);
   if (!s)
 
   s = state_hash_lookup (core_size, core);
   if (!s)


@@ -227,7 +227,7 @@ get_state (symbol_number sym, size_t core_size, item_number *core)
 
 /*---------------------------------------------------------------.
 | 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 S.              |
+| numbers reached by each shift transition from S.               |

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


@@ -247,7 +247,7 @@ append_states (state *s)
       symbol_number sym = shift_symbol[i];
       int j;
       for (j = i; 0 < j && sym < shift_symbol[j - 1]; j--)
       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] = shift_symbol[j - 1];

       shift_symbol[j] = sym;
     }
 
       shift_symbol[j] = sym;
     }
 


@@ -272,20 +272,20 @@ save_reductions (state *s)
   size_t i;
 
   /* Find and count the active items that represent ends of rules. */
   size_t i;
 
   /* Find and count the active items that represent ends of rules. */

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

     {
       item_number item = ritem[itemset[i]];
       if (item_number_is_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;
-           }
-       }
+        {
+          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.  */


@@ -307,14 +307,14 @@ set_states (void)
       state_list *this = first_state;
 
       /* Pessimization, but simplification of the code: make sure all
       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.  */
+         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 *s = this->state;
       if (!s->transitions)
       state *s = this->state;
       if (!s->transitions)

-       state_transitions_set (s, 0, 0);
+        state_transitions_set (s, 0, 0);

       if (!s->reductions)
       if (!s->reductions)

-       state_reductions_set (s, 0, 0);
+        state_reductions_set (s, 0, 0);

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


@@ -327,8 +327,8 @@ set_states (void)
 
 
 /*-------------------------------------------------------------------.
 
 
 /*-------------------------------------------------------------------.

-| Compute the nondeterministic finite state machine (see state.h for |
-| details) from the grammar.                                         |
+| Compute the LR(0) parser states (see state.h for details) from the |
+| grammar.                                                           |

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


@@ -348,13 +348,11 @@ generate_states (void)
     {
       state *s = list->state;
       if (trace_flag & trace_automaton)
     {
       state *s = list->state;
       if (trace_flag & trace_automaton)

-       fprintf (stderr, "Processing state %d (reached by %s)\n",
-                s->number,
-                symbols[s->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.  */
+        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.  */
       save_reductions (s);
       closure (s->items, s->nitems);
       /* Record the reductions allowed out of this state.  */
       save_reductions (s);


@@ -364,7 +362,7 @@ generate_states (void)
       append_states (s);
 
       /* Create the shifts structures for the shifts to those states,
       append_states (s);
 
       /* Create the shifts structures for the shifts to those states,

-        now that the state numbers transitioning to are known.  */
+         now that the state numbers transitioning to are known.  */

       state_transitions_set (s, nshifts, shiftset);
     }
 
       state_transitions_set (s, nshifts, shiftset);
     }