Update

[bison.git] / src / closure.c

diff --git a/src/closure.c b/src/closure.c
index d24fee37a285531b486d3e6d0e15b24f8ed5fb00..6d3d22078faabdced2af1a5081d2b6e6c819e9d5 100644 (file)
--- a/src/closure.c
+++ b/src/closure.c
@@ -1,118 +1,180 @@
 /* Subroutines for bison
 /* Subroutines for bison

-   Copyright (C) 1984, 1989 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000 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
-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.
+   Bison 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 2, or (at your option)
+   any later version.

 
 

-Bison 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.
+   Bison 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 Bison; see the file COPYING.  If not, write to
-the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
+   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.  */

 
 

+#include "system.h"
+#include "xalloc.h"
+#include "gram.h"
+#include "closure.h"
+#include "derives.h"
+#include "warshall.h"

 
 

-/* subroutines of file LR0.c.
+short *itemset;
+short *itemsetend;
+static unsigned *ruleset;

 
 

-Entry points:
+/* internal data.  See comments before set_fderives and set_firsts.  */
+static unsigned *fderives;
+static unsigned *firsts;

 
 

-  closure (items, n)
+/* number of words required to hold a bit for each rule */
+static int rulesetsize;

 
 

-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.
+/* number of words required to hold a bit for each variable */
+static int varsetsize;
+\f
+#if DEBUG

 
 

-ruleset contains a bit for each rule.  closure sets the bits
-for all rules which could potentially describe the next input to be read.
+/*-----------------.
+| Debugging code.  |
+`-----------------*/

 
 

-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.
+static void
+print_closure (int n)
+{
+  short *isp;

 
 

-  initialize_closure (n)
+  printf ("\n\nn = %d\n\n", n);
+  for (isp = itemset; isp < itemsetend; isp++)
+    printf ("   %d\n", *isp);
+}

 
 

-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 ()
+static void
+print_firsts (void)
+{
+  int i;
+  int j;
+  unsigned *rowp;

 
 

-Frees itemset, ruleset and internal data.
+  printf ("\n\n\nFIRSTS\n\n");

 
 

-*/
+  for (i = ntokens; i < nsyms; i++)
+    {
+      printf ("\n\n%s firsts\n\n", tags[i]);

 
 

-#include <stdio.h>
-#include "system.h"
-#include "machine.h"
-#include "new.h"
-#include "gram.h"
+      rowp = firsts + ((i - ntokens) * varsetsize);

 
 

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

 
 

-extern short **derives;
-extern char **tags;

 
 

-void set_fderives();
-void set_firsts();
+static void
+print_fderives (void)
+{
+  int i;
+  int j;
+  unsigned *rp;

 
 

-extern void RTC();
+  printf ("\n\n\nFDERIVES\n");

 
 

-short *itemset;
-short *itemsetend;
-static unsigned *ruleset;
+  for (i = ntokens; i < nsyms; i++)
+    {
+      printf ("\n\n%s derives\n\n", tags[i]);
+      rp = fderives + i * rulesetsize;

 
 

-/* internal data.  See comments before set_fderives and set_firsts.  */
-static unsigned *fderives;
-static unsigned *firsts;
+      for (j = 0; j <= nrules; j++)
+       if (BITISSET (rp, j))
+         printf ("   %d\n", j);
+    }

 
 

-/* number of words required to hold a bit for each rule */
-static int rulesetsize;
+  fflush (stdout);
+}
+#endif
+\f
+/*-------------------------------------------------------------------.
+| 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
+set_firsts (void)
+{
+  unsigned *row;
+  int symbol;
+  short *sp;
+  int rowsize;

 
 

-/* number of words required to hold a bit for each variable */
-static int varsetsize;
+  int i;

 
 

+  varsetsize = rowsize = WORDSIZE (nvars);

 
 

-void
-initialize_closure(n)
-int n;
-{
-  itemset = NEW2(n, short);
+  firsts = XCALLOC (unsigned, nvars * rowsize);

 
 

-  rulesetsize = WORDSIZE(nrules + 1);
-  ruleset = NEW2(rulesetsize, unsigned);
+  row = firsts;
+  for (i = ntokens; i < nsyms; i++)
+    {
+      sp = derives[i];
+      while (*sp >= 0)
+       {
+         symbol = ritem[rrhs[*sp++]];
+         if (ISVAR (symbol))
+           {
+             symbol -= ntokens;
+             SETBIT (row, symbol);
+           }
+       }

 
 

-  set_fderives();
-}
+      row += rowsize;
+    }

 
 

+  RTC (firsts, nvars);

 
 

+#ifdef DEBUG
+  print_firsts ();
+#endif
+}

 
 

-/* 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
-set_fderives()
+/*-------------------------------------------------------------------.
+| 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)

 {
 {

-  register unsigned *rrow;
-  register unsigned *vrow;
-  register int j;
-  register unsigned cword;
-  register short *rp;
-  register int b;
+  unsigned *rrow;
+  unsigned *vrow;
+  int j;
+  unsigned cword;
+  short *rp;
+  int b;

 
   int ruleno;
   int i;
 
 
   int ruleno;
   int i;
 

-  fderives = NEW2(nvars * rulesetsize, unsigned) - ntokens * rulesetsize;
+  fderives = XCALLOC (unsigned, nvars * rulesetsize) - ntokens * rulesetsize;

 
 

-  set_firsts();
+  set_firsts ();

 
   rrow = fderives + ntokens * rulesetsize;
 
 
   rrow = fderives + ntokens * rulesetsize;
 


@@ -128,7 +190,7 @@ set_fderives()
              rp = derives[j];
              while ((ruleno = *rp++) > 0)
                {
              rp = derives[j];
              while ((ruleno = *rp++) > 0)
                {

-                 SETBIT(rrow, ruleno);
+                 SETBIT (rrow, ruleno);

                }
            }
 
                }
            }
 


@@ -144,69 +206,34 @@ set_fderives()
     }
 
 #ifdef DEBUG
     }
 
 #ifdef DEBUG

-  print_fderives();
+  print_fderives ();

 #endif
 
 #endif
 

-  FREE(firsts);
+  XFREE (firsts);

 }
 }

+\f

 
 

-
-
-/* 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. */

 void
 void

-set_firsts()
+new_closure (int n)

 {
 {

-  register unsigned *row;
-/*   register int done; JF unused */
-  register int symbol;
-  register short *sp;
-  register int rowsize;
-
-  int i;
-
-  varsetsize = rowsize = WORDSIZE(nvars);
-
-  firsts = NEW2(nvars * rowsize, unsigned);
-
-  row = firsts;
-  for (i = ntokens; i < nsyms; i++)
-    {
-      sp = derives[i];
-      while (*sp >= 0)
-       {
-         symbol = ritem[rrhs[*sp++]];
-         if (ISVAR(symbol))
-           {
-             symbol -= ntokens;
-             SETBIT(row, symbol);
-           }
-       }
-
-      row += rowsize;
-    }
+  itemset = XCALLOC (short, n);

 
 

-  RTC(firsts, nvars);
+  rulesetsize = WORDSIZE (nrules + 1);
+  ruleset = XCALLOC (unsigned, rulesetsize);

 
 

-#ifdef DEBUG
-  print_firsts();
-#endif
+  set_fderives ();

 }
 
 
 }
 
 

+

 void
 void

-closure(core, n)
-short *core;
-int n;
+closure (short *core, int n)

 {
 {

-  register int ruleno;
-  register unsigned word;
-  register short *csp;
-  register unsigned *dsp;
-  register unsigned *rsp;
+  int ruleno;
+  unsigned word;
+  short *csp;
+  unsigned *dsp;
+  unsigned *rsp;

 
   short *csend;
   unsigned *rsend;
 
   short *csend;
   unsigned *rsend;


@@ -232,7 +259,7 @@ int n;
       while (csp < csend)
        {
          symbol = ritem[*csp++];
       while (csp < csend)
        {
          symbol = ritem[*csp++];

-         if (ISVAR(symbol))
+         if (ISVAR (symbol))

            {
              dsp = fderives + symbol * rulesetsize;
              rsp = ruleset;
            {
              dsp = fderives + symbol * rulesetsize;
              rsp = ruleset;


@@ -255,7 +282,7 @@ int n;
        }
       else
        {
        }
       else
        {

-         register int b;
+         int b;

 
          for (b = 0; b < BITS_PER_WORD; b++)
            {
 
          for (b = 0; b < BITS_PER_WORD; b++)
            {


@@ -275,77 +302,16 @@ int n;
   while (csp < csend)
     *itemsetend++ = *csp++;
 
   while (csp < csend)
     *itemsetend++ = *csp++;
 

-#ifdef DEBUG
-  print_closure(n);
+#if DEBUG
+  print_closure (n);

 #endif
 }
 
 
 void
 #endif
 }
 
 
 void

-finalize_closure()
-{
-  FREE(itemset);
-  FREE(ruleset);
-  FREE(fderives + ntokens * rulesetsize);
-}
-
-
-
-#ifdef DEBUG
-
-print_closure(n)
-int n;
+free_closure (void)

 {
 {

-  register short *isp;
-
-  printf("\n\nn = %d\n\n", n);
-  for (isp = itemset; isp < itemsetend; isp++)
-    printf("   %d\n", *isp);
-}
-
-
-
-print_firsts()
-{
-  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]);
-
-      rowp = firsts + ((i - ntokens) * varsetsize);
-
-      for (j = 0; j < nvars; j++)
-       if (BITISSET (rowp, j))
-         printf("   %s\n", tags[j + ntokens]);
-    }
+  XFREE (itemset);
+  XFREE (ruleset);
+  XFREE (fderives + ntokens * rulesetsize);

 }
 }

-
-
-
-print_fderives()
-{
-  register int i;
-  register int j;
-  register unsigned *rp;
-
-  printf(_("\n\n\nFDERIVES\n"));
-
-  for (i = ntokens; i < nsyms; i++)
-    {
-      printf(_("\n\n%s derives\n\n"), tags[i]);
-      rp = fderives + i * rulesetsize;
-
-      for (j = 0; j <= nrules; j++)
-       if (BITISSET (rp, j))
-         printf("   %d\n", j);
-    }
-
-  fflush(stdout);
-}
-
-#endif