Update.

[bison.git] / src / closure.c

diff --git a/src/closure.c b/src/closure.c
index 4e6fee00557e2fc52b08049b97dc60fa41dd072a..3d5ac28d0bcf69957980add665f832f67a517bd7 100644 (file)
--- a/src/closure.c
+++ b/src/closure.c
@@ -1,5 +1,5 @@
 /* Subroutines for bison
 /* Subroutines for bison

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

 
    This file is part of Bison, the GNU Compiler Compiler.
 
 
    This file is part of Bison, the GNU Compiler Compiler.
 


@@ -18,343 +18,227 @@
    Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
    02111-1307, USA.  */
 
    Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
    02111-1307, USA.  */
 

-
-/* Subroutines of file LR0.c.
-
-Entry points:
-
-  closure (items, n)
-
-Given a vector of item numbers items, of length n, set up ruleset and
-itemset to indicate what rules could be run and which items could be
-accepted when those items are the active ones.
-
-ruleset contains a bit for each rule.  closure sets the bits for all
-rules which could potentially describe the next input to be read.
-
-itemset is a vector of item numbers; itemsetend points to just beyond
-the end of the part of it that is significant.  closure places there
-the indices of all items which represent units of input that could
-arrive next.
-
-  initialize_closure (n)
-
-Allocates the itemset and ruleset vectors, and precomputes useful data
-so that closure can be called.  n is the number of elements to
-allocate for itemset.
-
-  finalize_closure ()
-
-Frees itemset, ruleset and internal data.
-
-*/
-

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

-#include "alloc.h"
+#include "quotearg.h"
+#include "bitset.h"
+#include "bitsetv.h"
+#include "bitsetv-print.h"
+#include "getargs.h"
+#include "symtab.h"

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

+#include "reader.h"
+#include "closure.h"
+#include "derives.h"

 
 

+/* NITEMSET is the size of the array ITEMSET.  */
+item_number_t *itemset;
+int nritemset;

 
 

-extern short **derives;
-extern char **tags;
-
-extern void initialize_closure PARAMS((int));
-extern void closure PARAMS((short *, int));
-extern void finalize_closure PARAMS((void));
-
-static void set_fderives PARAMS((void));
-static void set_firsts PARAMS((void));
-
-extern void RTC PARAMS((unsigned *, int));
-
-short *itemset;
-short *itemsetend;
-static unsigned *ruleset;
+static bitset ruleset;

 
 /* internal data.  See comments before set_fderives and set_firsts.  */
 
 /* internal data.  See comments before set_fderives and set_firsts.  */

-static unsigned *fderives;
-static unsigned *firsts;
-
-/* number of words required to hold a bit for each rule */
-static int rulesetsize;
+static bitsetv fderives = NULL;
+static bitsetv firsts = NULL;

 
 

-/* number of words required to hold a bit for each variable */
-static int varsetsize;
+/* Retrieve the FDERIVES/FIRSTS sets of the nonterminals numbered Var.  */
+#define FDERIVES(Var)   fderives[(Var) - ntokens]
+#define   FIRSTS(Var)   firsts[(Var) - ntokens]
+\f

 
 

-#ifdef DEBUG
-static void print_closure PARAMS((int));
-static void print_fderives PARAMS((void));
-static void print_firsts PARAMS((void));
-#endif
+/*-----------------.
+| Debugging code.  |
+`-----------------*/

 
 

-void
-initialize_closure (int n)
+static void
+print_closure (const char *title, item_number_t *array, size_t size)

 {
 {

-  itemset = NEW2(n, short);
-
-  rulesetsize = WORDSIZE(nrules + 1);
-  ruleset = NEW2(rulesetsize, unsigned);
-
-  set_fderives();
+  size_t i;
+  fprintf (stderr, "Closure: %s\n", title);
+  for (i = 0; i < size; ++i)
+    {
+      item_number_t *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);

 }
 
 
 }
 
 

-
-/* 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
 static void

-set_fderives (void)
+print_firsts (void)

 {
 {

-  register unsigned *rrow;
-  register unsigned *vrow;
-  register int j;
-  register unsigned cword;
-  register short *rp;
-  register int b;
-
-  int ruleno;
-  int i;
-
-  fderives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;
-
-  set_firsts();
-
-  rrow = fderives + ntokens * rulesetsize;
+  symbol_number_t i, j;

 
 

+  fprintf (stderr, "FIRSTS\n");

   for (i = ntokens; i < nsyms; i++)
     {
   for (i = ntokens; i < nsyms; i++)
     {

-      vrow = firsts + ((i - ntokens) * varsetsize);
-      cword = *vrow++;
-      b = 0;
-      for (j = ntokens; j < nsyms; j++)
+      bitset_iterator iter;
+      fprintf (stderr, "\t%s firsts\n", symbols[i]->tag);
+      BITSET_FOR_EACH (iter, FIRSTS (i), j, 0)

        {
        {

-         if (cword & (1 << b))
-           {
-             rp = derives[j];
-             while ((ruleno = *rp++) > 0)
-               {
-                 SETBIT(rrow, ruleno);
-               }
-           }
-
-         b++;
-         if (b >= BITS_PER_WORD && j + 1 < nsyms)
-           {
-             cword = *vrow++;
-             b = 0;
-           }
+         fprintf (stderr, "\t\t%s\n",
+                  symbols[j + ntokens]->tag);

        }
        }

-
-      rrow += rulesetsize;

     }
     }

-
-#ifdef DEBUG
-  print_fderives();
-#endif
-
-  FREE(firsts);
+  fprintf (stderr, "\n\n");

 }
 
 
 }
 
 

-
-/* set firsts to be an nvars by nvars bit matrix 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, 5 - ntokens] in firsts is
-   set. */
-

 static void
 static void

-set_firsts (void)
+print_fderives (void)

 {
 {

-  register unsigned *row;
-/*   register int done; JF unused */
-  register int symbol;
-  register short *sp;
-  register int rowsize;
-

   int i;
   int i;

+  rule_number_t r;

 
 

-  varsetsize = rowsize = WORDSIZE(nvars);
-
-  firsts = NEW2(nvars * rowsize, unsigned);
-
-  row = firsts;
+  fprintf (stderr, "FDERIVES\n");

   for (i = ntokens; i < nsyms; i++)
     {
   for (i = ntokens; i < nsyms; i++)
     {

-      sp = derives[i];
-      while (*sp >= 0)
+      bitset_iterator iter;
+      fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+      BITSET_FOR_EACH (iter, FDERIVES (i), r, 0)

        {
        {

-         symbol = ritem[rrhs[*sp++]];
-         if (ISVAR(symbol))
-           {
-             symbol -= ntokens;
-             SETBIT(row, symbol);
-           }
+         fprintf (stderr, "\t\t%3d ", r);
+         rule_rhs_print (&rules[r], stderr);

        }
        }

-
-      row += rowsize;

     }
     }

+  fprintf (stderr, "\n\n");
+}
+\f
+/*------------------------------------------------------------------.
+| 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.                                                      |
+`------------------------------------------------------------------*/

 
 

-  RTC(firsts, nvars);
+static void
+set_firsts (void)
+{
+  symbol_number_t i, j;

 
 

-#ifdef DEBUG
-  print_firsts ();
-#endif
+  firsts = bitsetv_create (nvars, nvars, BITSET_FIXED);
+
+  for (i = ntokens; i < nsyms; i++)
+    for (j = 0; derives[i][j]; ++j)
+      {
+       int symbol = derives[i][j]->rhs[0];
+       if (ISVAR (symbol))
+         bitset_set (FIRSTS (i), symbol - 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.                       |
+`-------------------------------------------------------------------*/

 
 

-void
-closure (short *core, int n)
+static void
+set_fderives (void)

 {
 {

-  register int ruleno;
-  register unsigned word;
-  register short *csp;
-  register unsigned *dsp;
-  register unsigned *rsp;
-
-  short *csend;
-  unsigned *rsend;
-  int symbol;
-  int itemno;
-
-  rsp = ruleset;
-  rsend = ruleset + rulesetsize;
-  csend = core + n;
-
-  if (n == 0)
-    {
-      dsp = fderives + start_symbol * rulesetsize;
-      while (rsp < rsend)
-       *rsp++ = *dsp++;
-    }
-  else
-    {
-      while (rsp < rsend)
-       *rsp++ = 0;
+  symbol_number_t i, j;
+  rule_number_t k;

 
 

-      csp = core;
-      while (csp < csend)
-       {
-         symbol = ritem[*csp++];
-         if (ISVAR(symbol))
-           {
-             dsp = fderives + symbol * rulesetsize;
-             rsp = ruleset;
-             while (rsp < rsend)
-               *rsp++ |= *dsp++;
-           }
-       }
-    }
+  fderives = bitsetv_create (nvars, nrules, BITSET_FIXED);

 
 

-  ruleno = 0;
-  itemsetend = itemset;
-  csp = core;
-  rsp = ruleset;
-  while (rsp < rsend)
-    {
-      word = *rsp++;
-      if (word == 0)
-       {
-         ruleno += BITS_PER_WORD;
-       }
-      else
-       {
-         register int b;
-
-         for (b = 0; b < BITS_PER_WORD; b++)
-           {
-             if (word & (1 << b))
-               {
-                 itemno = rrhs[ruleno];
-                 while (csp < csend && *csp < itemno)
-                   *itemsetend++ = *csp++;
-                 *itemsetend++ = itemno;
-               }
-
-             ruleno++;
-           }
-       }
-    }
+  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][k]; ++k)
+         bitset_set (FDERIVES (i), derives[j][k]->number);

 
 

-  while (csp < csend)
-    *itemsetend++ = *csp++;
+  if (trace_flag & trace_sets)
+    print_fderives ();

 
 

-#ifdef DEBUG
-  print_closure(n);
-#endif
+  bitsetv_free (firsts);

 }
 
 }
 

+\f

 
 void
 
 void

-finalize_closure (void)
+new_closure (int n)

 {
 {

-  FREE(itemset);
-  FREE(ruleset);
-  FREE(fderives + ntokens * rulesetsize);
-}
-
-
+  itemset = XCALLOC (item_number_t, n);

 
 

-#ifdef DEBUG
+  ruleset = bitset_create (nrules, BITSET_FIXED);

 
 

-static void
-print_closure(int n)
-{
-  register short *isp;
-
-  printf ("\n\nn = %d\n\n", n);
-  for (isp = itemset; isp < itemsetend; isp++)
-    printf ("   %d\n", *isp);
+  set_fderives ();

 }
 
 
 }
 
 

-static void
-print_firsts (void)
-{
-  register int i;
-  register int j;
-  register unsigned *rowp;
-
-  printf ("\n\n\nFIRSTS\n\n");

 
 

-  for (i = ntokens; i < nsyms; i++)
-    {
-      printf ("\n\n%s firsts\n\n", tags[i]);
+void
+closure (item_number_t *core, int n)
+{
+  /* Index over CORE. */
+  int c;

 
 

-      rowp = firsts + ((i - ntokens) * varsetsize);
+  /* A bit index over RULESET. */
+  rule_number_t ruleno;

 
 

-      for (j = 0; j < nvars; j++)
-       if (BITISSET (rowp, j))
-         printf ("   %s\n", tags[j + ntokens]);
-    }
-}
+  bitset_iterator iter;

 
 

+  if (trace_flag & trace_sets)
+    print_closure ("input", core, n);

 
 

-static void
-print_fderives (void)
-{
-  register int i;
-  register int j;
-  register unsigned *rp;
+  bitset_zero (ruleset);

 
 

-  printf ("\n\n\nFDERIVES\n");
+  for (c = 0; c < n; ++c)
+    if (ISVAR (ritem[core[c]]))
+      bitset_or (ruleset, ruleset, FDERIVES (ritem[core[c]]));

 
 

-  for (i = ntokens; i < nsyms; i++)
+  nritemset = 0;
+  c = 0;
+  BITSET_FOR_EACH (iter, ruleset, ruleno, 0)

     {
     {

-      printf ("\n\n%s derives\n\n", tags[i]);
-      rp = fderives + i * rulesetsize;
+      item_number_t itemno = rules[ruleno].rhs - ritem;
+      while (c < n && core[c] < itemno)
+       {
+         itemset[nritemset] = core[c];
+         nritemset++;
+         c++;
+       }
+      itemset[nritemset] = itemno;
+      nritemset++;
+    };

 
 

-      for (j = 0; j <= nrules; j++)
-       if (BITISSET (rp, j))
-         printf ("   %d\n", j);
+  while (c < n)
+    {
+      itemset[nritemset] = core[c];
+      nritemset++;
+      c++;

     }
 
     }
 

-  fflush(stdout);
+  if (trace_flag & trace_sets)
+    print_closure ("output", itemset, nritemset);

 }
 
 }
 

-#endif
+
+void
+free_closure (void)
+{
+  XFREE (itemset);
+  bitset_free (ruleset);
+  bitsetv_free (fderives);
+}