/* Match rules with nonterminals for bison,
- Copyright (C) 1984, 1989 Free Software Foundation, Inc.
-This file is part of Bison, the GNU Compiler Compiler.
+ Copyright (C) 1984, 1989, 2000, 2001, 2002, 2003 Free Software
+ Foundation, Inc.
-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.
+ This file is part of Bison, the GNU Compiler Compiler.
-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 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.
-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. */
+ 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, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, 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 <stdio.h>
#include "system.h"
-#include "alloc.h"
-#include "types.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;
-short **derives;
+rule ***derives;
-void
-set_derives()
+static void
+print_derives (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--)
- {
- lhs = rlhs[i];
- if (lhs >= 0)
- {
- p->next = dset[lhs];
- p->value = i;
- dset[lhs] = p;
- p++;
- }
- }
+ int i;
- derives = NEW2(nvars, short *) - ntokens;
- q = NEW2(nvars + nrules, short);
+ fputs ("DERIVES\n", stderr);
for (i = ntokens; i < nsyms; i++)
{
- derives[i] = q;
- p = dset[i];
- while (p)
+ rule **rp;
+ fprintf (stderr, "\t%s derives\n", symbols[i]->tag);
+ for (rp = derives[i - ntokens]; *rp; ++rp)
{
- *q++ = p->value;
- p = p->next;
+ fprintf (stderr, "\t\t%3d ", (*rp)->user_number);
+ rule_rhs_print (*rp, stderr);
}
- *q++ = -1;
}
-#ifdef DEBUG
- print_derives();
-#endif
-
- FREE(dset + ntokens);
- FREE(delts);
+ fputs ("\n\n", stderr);
}
+
void
-free_derives()
+derives_compute (void)
{
- FREE(derives[ntokens]);
- FREE(derives + ntokens);
-}
-
+ 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);
-#ifdef DEBUG
+ /* 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);
-print_derives()
-{
- register int i;
- register short *sp;
+ for (r = nrules - 1; r >= 0; --r)
+ {
+ 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;
+ }
- extern char **tags;
+ /* DSET contains what we need under the form of a linked list. Make
+ it a single array. */
- printf(_("\n\n\nDERIVES\n\n"));
+ derives = xnmalloc (nvars, sizeof *derives);
+ q = xnmalloc (nvars + nrules, sizeof *q);
for (i = ntokens; i < nsyms; i++)
{
- printf(_("%s derives"), tags[i]);
- for (sp = derives[i]; *sp > 0; sp++)
+ rule_list *p = dset[i - ntokens];
+ derives[i - ntokens] = q;
+ while (p)
{
- printf(" %d", *sp);
+ *q++ = p->value;
+ p = p->next;
}
- putchar('\n');
+ *q++ = NULL;
}
- putchar('\n');
+ if (trace_flag & trace_sets)
+ print_derives ();
+
+ free (dset);
+ free (delts);
}
-#endif
+void
+derives_free (void)
+{
+ free (derives[0]);
+ free (derives);
+}