* src/closure.c (closure): Use arrays instead of pointers to clarify.

[bison.git] / src / closure.c

diff --git a/src/closure.c b/src/closure.c
index 03a59f0bfb79732f9ba8c26e52db79c1547cd2b4..09d835002645d855dc801728866291ca26e6cdf5 100644 (file)
--- a/src/closure.c
+++ b/src/closure.c
@@ -1,5 +1,5 @@
 /* Subroutines for bison
-   Copyright 1984, 1989, 2000 Free Software Foundation, Inc.
+   Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
 
    This file is part of Bison, the GNU Compiler Compiler.
 
@@ -19,7 +19,9 @@
    02111-1307, USA.  */
 
 #include "system.h"
+#include "getargs.h"
 #include "gram.h"
+#include "reader.h"
 #include "closure.h"
 #include "derives.h"
 #include "warshall.h"
@@ -32,13 +34,15 @@ static unsigned *ruleset;
 static unsigned *fderives;
 static unsigned *firsts;
 
+#define FDERIVES(Symbol)   (fderives + (Symbol) * rulesetsize)
+#define   FIRSTS(Symbol)   (firsts   + (Symbol) * varsetsize)
+
 /* number of words required to hold a bit for each rule */
 static int rulesetsize;
 
 /* number of words required to hold a bit for each variable */
 static int varsetsize;
 \f
-#if DEBUG
 
 /*-----------------.
 | Debugging code.  |
@@ -49,9 +53,10 @@ print_closure (int n)
 {
   short *isp;
 
-  printf ("\n\nn = %d\n\n", n);
+  fprintf (stderr, "n = %d\n", n);
   for (isp = itemset; isp < itemsetend; isp++)
-    printf ("   %d\n", *isp);
+    fprintf (stderr, "   %d\n", *isp);
+  fprintf (stderr, "\n\n");
 }
 
 
@@ -62,18 +67,19 @@ print_firsts (void)
   int j;
   unsigned *rowp;
 
-  printf ("\n\n\nFIRSTS\n\n");
+  fprintf (stderr, "FIRSTS\n");
 
   for (i = ntokens; i < nsyms; i++)
     {
-      printf ("\n\n%s firsts\n\n", tags[i]);
+      fprintf (stderr, "\t%s firsts\n", tags[i]);
 
-      rowp = firsts + ((i - ntokens) * varsetsize);
+      rowp = FIRSTS (i - ntokens);
 
       for (j = 0; j < nvars; j++)
        if (BITISSET (rowp, j))
-         printf ("   %s\n", tags[j + ntokens]);
+         fprintf (stderr, "\t\t%d (%s)\n", j + ntokens, tags[j + ntokens]);
     }
+  fprintf (stderr, "\n\n");
 }
 
 
@@ -84,21 +90,19 @@ print_fderives (void)
   int j;
   unsigned *rp;
 
-  printf ("\n\n\nFDERIVES\n");
+  fprintf (stderr, "FDERIVES\n");
 
   for (i = ntokens; i < nsyms; i++)
     {
-      printf ("\n\n%s derives\n\n", tags[i]);
-      rp = fderives + i * rulesetsize;
+      fprintf (stderr, "\t%s derives\n", tags[i]);
+      rp = FDERIVES (i);
 
       for (j = 0; j <= nrules; j++)
        if (BITISSET (rp, j))
-         printf ("   %d\n", j);
+         fprintf (stderr, "\t\t%d (%s)\n", j, tags[j]);
     }
-
-  fflush (stdout);
+  fprintf (stderr, "\n\n");
 }
-#endif
 \f
 /*-------------------------------------------------------------------.
 | Set FIRSTS to be an NVARS by NVARS bit matrix indicating which     |
@@ -130,7 +134,7 @@ set_firsts (void)
       sp = derives[i];
       while (*sp >= 0)
        {
-         symbol = ritem[rrhs[*sp++]];
+         symbol = ritem[rule_table[*sp++].rhs];
          if (ISVAR (symbol))
            {
              symbol -= ntokens;
@@ -143,9 +147,8 @@ set_firsts (void)
 
   RTC (firsts, nvars);
 
-#ifdef DEBUG
-  print_firsts ();
-#endif
+  if (trace_flag)
+    print_firsts ();
 }
 
 /*-------------------------------------------------------------------.
@@ -175,11 +178,11 @@ set_fderives (void)
 
   set_firsts ();
 
-  rrow = fderives + ntokens * rulesetsize;
+  rrow = FDERIVES (ntokens);
 
   for (i = ntokens; i < nsyms; i++)
     {
-      vrow = firsts + ((i - ntokens) * varsetsize);
+      vrow = FIRSTS (i - ntokens);
       cword = *vrow++;
       b = 0;
       for (j = ntokens; j < nsyms; j++)
@@ -188,9 +191,7 @@ set_fderives (void)
            {
              rp = derives[j];
              while ((ruleno = *rp++) > 0)
-               {
-                 SETBIT (rrow, ruleno);
-               }
+               SETBIT (rrow, ruleno);
            }
 
          b++;
@@ -204,9 +205,8 @@ set_fderives (void)
       rrow += rulesetsize;
     }
 
-#ifdef DEBUG
-  print_fderives ();
-#endif
+  if (trace_flag)
+    print_fderives ();
 
   XFREE (firsts);
 }
@@ -229,41 +229,37 @@ void
 closure (short *core, int n)
 {
   int ruleno;
-  unsigned word;
   short *csp;
-  unsigned *dsp;
-  unsigned *rsp;
 
-  short *csend;
-  unsigned *rsend;
-  int symbol;
   int itemno;
+  int i;
 
-  rsp = ruleset;
-  rsend = ruleset + rulesetsize;
-  csend = core + n;
+  if (trace_flag)
+    {
+      fprintf (stderr, "Entering closure (items = {");
+      for (i = 0; i < n; ++i)
+       fprintf (stderr, " %d ", core[i]);
+      fprintf (stderr, "}, nitems = %d)\n", n);
+    }
 
   if (n == 0)
     {
-      dsp = fderives + start_symbol * rulesetsize;
-      while (rsp < rsend)
-       *rsp++ = *dsp++;
+      for (i = 0; i < rulesetsize; ++i)
+       ruleset[i] = FDERIVES (start_symbol)[i];
     }
   else
     {
-      while (rsp < rsend)
-       *rsp++ = 0;
+      for (i = 0; i < rulesetsize; ++i)
+       ruleset[i] = 0;
 
-      csp = core;
-      while (csp < csend)
+      for (i = 0; i < n; ++i)
        {
-         symbol = ritem[*csp++];
+         int symbol = ritem[core[i]];
          if (ISVAR (symbol))
            {
-             dsp = fderives + symbol * rulesetsize;
-             rsp = ruleset;
-             while (rsp < rsend)
-               *rsp++ |= *dsp++;
+             int j;
+             for (j = 0; j < rulesetsize; ++j)
+               ruleset[j] |= FDERIVES (symbol)[j];
            }
        }
     }
@@ -271,10 +267,9 @@ closure (short *core, int n)
   ruleno = 0;
   itemsetend = itemset;
   csp = core;
-  rsp = ruleset;
-  while (rsp < rsend)
+  for (i= 0; i < rulesetsize; ++i)
     {
-      word = *rsp++;
+      int word = ruleset[i];
       if (word == 0)
        {
          ruleno += BITS_PER_WORD;
@@ -287,8 +282,8 @@ closure (short *core, int n)
            {
              if (word & (1 << b))
                {
-                 itemno = rrhs[ruleno];
-                 while (csp < csend && *csp < itemno)
+                 itemno = rule_table[ruleno].rhs;
+                 while (csp < (core + n ) && *csp < itemno)
                    *itemsetend++ = *csp++;
                  *itemsetend++ = itemno;
                }
@@ -298,12 +293,11 @@ closure (short *core, int n)
        }
     }
 
-  while (csp < csend)
+  while (csp < (core + n))
     *itemsetend++ = *csp++;
 
-#if DEBUG
-  print_closure (n);
-#endif
+  if (trace_flag)
+    print_closure (n);
 }