-/* Part of the bison parser generator,
- Copyright (C) 1984, 1989, 2000, 2001, 2002 Free Software Foundation, Inc.
+/* Calculate which nonterminals can expand into the null string for Bison.
+
+ Copyright (C) 1984, 1989, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+ Free Software Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
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. */
+ the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA. */
/* Set up NULLABLE, a vector saying which nonterminals can expand into
the null string. NULLABLE[I - NTOKENS] is nonzero if symbol I can
do so. */
+#include <config.h>
#include "system.h"
#include "getargs.h"
int i;
fputs ("NULLABLE\n", out);
for (i = ntokens; i < nsyms; i++)
- fprintf (out, "\t%s: %s\n", symbols[i]->tag, nullable[i] ? "yes" : "no");
+ fprintf (out, "\t%s: %s\n", symbols[i]->tag,
+ nullable[i - ntokens] ? "yes" : "no");
fputs ("\n\n", out);
}
symbol_number *s2;
rule_list *p;
- symbol_number *squeue = XCALLOC (symbol_number, nvars);
- short *rcount = XCALLOC (short, nrules);
+ symbol_number *squeue = xnmalloc (nvars, sizeof *squeue);
+ size_t *rcount = xcalloc (nrules, sizeof *rcount);
/* RITEM contains all the rules, including useless productions.
Hence we must allocate room for useless nonterminals too. */
- rule_list **rsets = XCALLOC (rule_list *, nvars) - ntokens;
+ rule_list **rsets = xcalloc (nvars, sizeof *rsets);
/* This is said to be more elements than we actually use.
Supposedly NRITEMS - NRULES is enough. But why take the risk? */
- rule_list *relts = XCALLOC (rule_list, nritems + nvars + 1);
+ rule_list *relts = xnmalloc (nritems + nvars + 1, sizeof *relts);
- nullable = XCALLOC (bool, nvars) - ntokens;
+ nullable = xcalloc (nvars, sizeof *nullable);
s1 = s2 = squeue;
p = relts;
if (rules_ruleno->rhs[0] >= 0)
{
/* This rule has a non empty RHS. */
- item_number *r = NULL;
- int any_tokens = 0;
- for (r = rules_ruleno->rhs; *r >= 0; ++r)
- if (ISTOKEN (*r))
- any_tokens = 1;
+ item_number *rp = NULL;
+ bool any_tokens = false;
+ for (rp = rules_ruleno->rhs; *rp >= 0; ++rp)
+ if (ISTOKEN (*rp))
+ any_tokens = true;
/* This rule has only nonterminals: schedule it for the second
pass. */
if (!any_tokens)
- for (r = rules_ruleno->rhs; *r >= 0; ++r)
+ for (rp = rules_ruleno->rhs; *rp >= 0; ++rp)
{
rcount[ruleno]++;
- p->next = rsets[*r];
+ p->next = rsets[*rp - ntokens];
p->value = rules_ruleno;
- rsets[*r] = p;
+ rsets[*rp - ntokens] = p;
p++;
}
}
else
{
/* This rule has an empty RHS. */
- if (item_number_as_rule_number (rules_ruleno->rhs[0]) != ruleno)
- abort ();
- if (rules_ruleno->useful && !nullable[rules_ruleno->lhs->number])
+ aver (item_number_as_rule_number (rules_ruleno->rhs[0])
+ == ruleno);
+ if (rules_ruleno->useful
+ && ! nullable[rules_ruleno->lhs->number - ntokens])
{
- nullable[rules_ruleno->lhs->number] = 1;
+ nullable[rules_ruleno->lhs->number - ntokens] = true;
*s2++ = rules_ruleno->lhs->number;
}
}
}
while (s1 < s2)
- for (p = rsets[*s1++]; p; p = p->next)
+ for (p = rsets[*s1++ - ntokens]; p; p = p->next)
{
rule *r = p->value;
if (--rcount[r->number] == 0)
- if (r->useful && !nullable[r->lhs->number])
+ if (r->useful && ! nullable[r->lhs->number - ntokens])
{
- nullable[r->lhs->number] = 1;
+ nullable[r->lhs->number - ntokens] = true;
*s2++ = r->lhs->number;
}
}
- XFREE (squeue);
- XFREE (rcount);
- XFREE (rsets + ntokens);
- XFREE (relts);
+ free (squeue);
+ free (rcount);
+ free (rsets);
+ free (relts);
if (trace_flag & trace_sets)
nullable_print (stderr);
void
nullable_free (void)
{
- XFREE (nullable + ntokens);
+ free (nullable);
}