/* Match rules with nonterminals for bison,
- Copyright (C) 1984, 1989, 2000 Free Software Foundation, Inc.
+
+ Copyright (C) 1984, 1989, 2000, 2001, 2002, 2003 Free Software
+ Foundation, Inc.
This file is part of Bison, the GNU Compiler Compiler.
Boston, MA 02111-1307, USA. */
-/* set_derives finds, for each variable (nonterminal), which rules can
- derive it. It sets up the value of derives so that derives[i -
- ntokens] points to a vector of rule numbers, terminated with -1.
- */
-
#include "system.h"
-#include "alloc.h"
-#include "types.h"
-#include "gram.h"
+
+#include "getargs.h"
+
#include "derives.h"
+#include "gram.h"
+#include "reader.h"
+#include "symtab.h"
+
+/* Linked list of rule numbers. */
+typedef struct rule_list
+{
+ struct rule_list *next;
+ rule *value;
+} rule_list;
-#if DEBUG
-extern char **tags;
+rule ***derives;
static void
print_derives (void)
{
- register int i;
- register short *sp;
+ int i;
- printf (_("\n\n\nDERIVES\n\n"));
+ fputs ("DERIVES\n", stderr);
for (i = ntokens; i < nsyms; i++)
{
- printf (_("%s derives"), tags[i]);
- for (sp = derives[i]; *sp > 0; sp++)
+ rule **rp;
+ fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+ for (rp = derives[i - ntokens]; *rp; ++rp)
{
- printf (" %d", *sp);
+ fprintf (stderr, "\t\t%3d ", (*rp)->user_number);
+ rule_rhs_print (*rp, stderr);
}
- putchar ('\n');
}
- putchar ('\n');
+ fputs ("\n\n", stderr);
}
-#endif
-
-short **derives;
void
-set_derives (void)
+derives_compute (void)
{
- register int i;
- register int lhs;
- register shorts *p;
- register short *q;
- register shorts **dset;
- register shorts *delts;
-
- dset = NEW2 (nvars, shorts *) - ntokens;
- delts = NEW2 (nrules + 1, shorts);
-
- p = delts;
- for (i = nrules; i > 0; i--)
+ symbol_number i;
+ rule_number r;
+ rule **q;
+
+ /* DSET[NTERM - NTOKENS] -- A linked list of the numbers of the rules
+ whose LHS is NTERM. */
+ rule_list **dset = xcalloc (nvars, sizeof *dset);
+
+ /* DELTS[RULE] -- There are NRULES rule number to attach to nterms.
+ Instead of performing NRULES allocations for each, have an array
+ indexed by rule numbers. */
+ rule_list *delts = xnmalloc (nrules, sizeof *delts);
+
+ for (r = nrules - 1; r >= 0; --r)
{
- lhs = rlhs[i];
- if (lhs >= 0)
- {
- p->next = dset[lhs];
- p->value = i;
- dset[lhs] = p;
- p++;
- }
+ symbol_number lhs = rules[r].lhs->number;
+ rule_list *p = &delts[r];
+ /* A new LHS is found. */
+ p->next = dset[lhs - ntokens];
+ p->value = &rules[r];
+ dset[lhs - ntokens] = p;
}
- derives = NEW2 (nvars, short *) - ntokens;
- q = NEW2 (nvars + nrules, short);
+ /* DSET contains what we need under the form of a linked list. Make
+ it a single array. */
+
+ derives = xnmalloc (nvars, sizeof *derives);
+ q = xnmalloc (nvars + nrules, sizeof *q);
for (i = ntokens; i < nsyms; i++)
{
- derives[i] = q;
- p = dset[i];
+ rule_list *p = dset[i - ntokens];
+ derives[i - ntokens] = q;
while (p)
{
*q++ = p->value;
p = p->next;
}
- *q++ = -1;
+ *q++ = NULL;
}
-#if DEBUG
- print_derives ();
-#endif
+ if (trace_flag & trace_sets)
+ print_derives ();
- FREE (dset + ntokens);
- FREE (delts);
+ free (dset);
+ free (delts);
}
+
void
-free_derives (void)
+derives_free (void)
{
- FREE (derives[ntokens]);
- FREE (derives + ntokens);
+ free (derives[0]);
+ free (derives);
}