Add native Windows binary for bison.

bison/src/bison/2.4.1/bison-2.4.1-src/src/closure.c

+/* Closures for Bison
+
+   Copyright (C) 1984, 1989, 2000, 2001, 2002, 2004, 2005, 2007 Free
+   Software Foundation, Inc.
+
+   This file is part of Bison, the GNU Compiler Compiler.
+
+   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.
+
+   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 this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <config.h>
+#include "system.h"
+
+#include <bitset.h>
+#include <bitsetv-print.h>
+#include <bitsetv.h>
+#include <quotearg.h>
+
+#include "closure.h"
+#include "derives.h"
+#include "getargs.h"
+#include "gram.h"
+#include "reader.h"
+#include "symtab.h"
+
+/* NITEMSET is the size of the array ITEMSET.  */
+item_number *itemset;
+size_t nitemset;
+
+static bitset ruleset;
+
+/* internal data.  See comments before set_fderives and set_firsts.  */
+static bitsetv fderives = NULL;
+static bitsetv firsts = NULL;
+
+/* Retrieve the FDERIVES/FIRSTS sets of the nonterminals numbered Var.  */
+#define FDERIVES(Var)   fderives[(Var) - ntokens]
+#define   FIRSTS(Var)   firsts[(Var) - ntokens]
+
+
+/*-----------------.
+| Debugging code.  |
+`-----------------*/
+
+static void
+print_closure (char const *title, item_number *array, size_t size)
+{
+  size_t i;
+  fprintf (stderr, "Closure: %s\n", title);
+  for (i = 0; i < size; ++i)
+    {
+      item_number *rp;
+      fprintf (stderr, "  %2d: .", array[i]);
+      for (rp = &ritem[array[i]]; *rp >= 0; ++rp)
+        fprintf (stderr, " %s", symbols[*rp]->tag);
+      fprintf (stderr, "  (rule %d)\n", -*rp - 1);
+    }
+  fputs ("\n\n", stderr);
+}
+
+
+static void
+print_firsts (void)
+{
+  symbol_number i, j;
+
+  fprintf (stderr, "FIRSTS\n");
+  for (i = ntokens; i < nsyms; i++)
+    {
+      bitset_iterator iter;
+      fprintf (stderr, "\t%s firsts\n", symbols[i]->tag);
+      BITSET_FOR_EACH (iter, FIRSTS (i), j, 0)
+        {
+          fprintf (stderr, "\t\t%s\n",
+                   symbols[j + ntokens]->tag);
+        }
+    }
+  fprintf (stderr, "\n\n");
+}
+
+
+static void
+print_fderives (void)
+{
+  int i;
+  rule_number r;
+
+  fprintf (stderr, "FDERIVES\n");
+  for (i = ntokens; i < nsyms; i++)
+    {
+      bitset_iterator iter;
+      fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+      BITSET_FOR_EACH (iter, FDERIVES (i), r, 0)
+        {
+          fprintf (stderr, "\t\t%3d ", r);
+          rule_rhs_print (&rules[r], stderr);
+        }
+    }
+  fprintf (stderr, "\n\n");
+}
+
+/*------------------------------------------------------------------.
+| Set FIRSTS to be an NVARS array of NVARS bitsets indicating which |
+| items can represent the beginning of the input corresponding to   |
+| which other items.                                                |
+|                                                                   |
+| For example, if some rule expands symbol 5 into the sequence of   |
+| symbols 8 3 20, the symbol 8 can be the beginning of the data for |
+| symbol 5, so the bit [8 - ntokens] in first[5 - ntokens] (= FIRST |
+| (5)) is set.                                                      |
+`------------------------------------------------------------------*/
+
+static void
+set_firsts (void)
+{
+  symbol_number i, j;
+
+  firsts = bitsetv_create (nvars, nvars, BITSET_FIXED);
+
+  for (i = ntokens; i < nsyms; i++)
+    for (j = 0; derives[i - ntokens][j]; ++j)
+      {
+        item_number sym = derives[i - ntokens][j]->rhs[0];
+        if (ISVAR (sym))
+          bitset_set (FIRSTS (i), sym - ntokens);
+      }
+
+  if (trace_flag & trace_sets)
+    bitsetv_matrix_dump (stderr, "RTC: Firsts Input", firsts);
+  bitsetv_reflexive_transitive_closure (firsts);
+  if (trace_flag & trace_sets)
+    bitsetv_matrix_dump (stderr, "RTC: Firsts Output", firsts);
+
+  if (trace_flag & trace_sets)
+    print_firsts ();
+}
+
+/*-------------------------------------------------------------------.
+| Set FDERIVES to an NVARS by NRULES matrix of bits indicating which |
+| rules can help derive the beginning of the data for each           |
+| nonterminal.                                                       |
+|                                                                    |
+| For example, if symbol 5 can be derived as the sequence of symbols |
+| 8 3 20, and one of the rules for deriving symbol 8 is rule 4, then |
+| the [5 - NTOKENS, 4] bit in FDERIVES is set.                       |
+`-------------------------------------------------------------------*/
+
+static void
+set_fderives (void)
+{
+  symbol_number i, j;
+  rule_number k;
+
+  fderives = bitsetv_create (nvars, nrules, BITSET_FIXED);
+
+  set_firsts ();
+
+  for (i = ntokens; i < nsyms; ++i)
+    for (j = ntokens; j < nsyms; ++j)
+      if (bitset_test (FIRSTS (i), j - ntokens))
+        for (k = 0; derives[j - ntokens][k]; ++k)
+          bitset_set (FDERIVES (i), derives[j - ntokens][k]->number);
+
+  if (trace_flag & trace_sets)
+    print_fderives ();
+
+  bitsetv_free (firsts);
+}
+
+
+
+void
+new_closure (unsigned int n)
+{
+  itemset = xnmalloc (n, sizeof *itemset);
+
+  ruleset = bitset_create (nrules, BITSET_FIXED);
+
+  set_fderives ();
+}
+
+
+
+void
+closure (item_number *core, size_t n)
+{
+  /* Index over CORE. */
+  size_t c;
+
+  /* A bit index over RULESET. */
+  rule_number ruleno;
+
+  bitset_iterator iter;
+
+  if (trace_flag & trace_sets)
+    print_closure ("input", core, n);
+
+  bitset_zero (ruleset);
+
+  for (c = 0; c < n; ++c)
+    if (ISVAR (ritem[core[c]]))
+      bitset_or (ruleset, ruleset, FDERIVES (ritem[core[c]]));
+
+  /* core is sorted on item index in ritem, which is sorted on rule number.
+     Compute itemset with the same sort.  */
+  nitemset = 0;
+  c = 0;
+  BITSET_FOR_EACH (iter, ruleset, ruleno, 0)
+    {
+      item_number itemno = rules[ruleno].rhs - ritem;
+      while (c < n && core[c] < itemno)
+        {
+          itemset[nitemset] = core[c];
+          nitemset++;
+          c++;
+        }
+      itemset[nitemset] = itemno;
+      nitemset++;
+    };
+
+  while (c < n)
+    {
+      itemset[nitemset] = core[c];
+      nitemset++;
+      c++;
+    }
+
+  if (trace_flag & trace_sets)
+    print_closure ("output", itemset, nitemset);
+}
+
+
+void
+free_closure (void)
+{
+  free (itemset);
+  bitset_free (ruleset);
+  bitsetv_free (fderives);
+}