mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-20 11:11:24 +00:00
9f36c7f497
In case you're wondering, the gcc-2.7.2.1 import uses this to generate code. The size of the generated code is bigger than the entire bison release, making this a saving. The bison doc is pretty good apparently.
119 lines
2.2 KiB
C
119 lines
2.2 KiB
C
/* Match rules with nonterminals for bison,
|
|
Copyright (C) 1984, 1989 Free Software Foundation, Inc.
|
|
|
|
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 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. */
|
|
|
|
|
|
/* 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 "new.h"
|
|
#include "types.h"
|
|
#include "gram.h"
|
|
|
|
|
|
short **derives;
|
|
|
|
void
|
|
set_derives()
|
|
{
|
|
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++;
|
|
}
|
|
}
|
|
|
|
derives = NEW2(nvars, short *) - ntokens;
|
|
q = NEW2(nvars + nrules, short);
|
|
|
|
for (i = ntokens; i < nsyms; i++)
|
|
{
|
|
derives[i] = q;
|
|
p = dset[i];
|
|
while (p)
|
|
{
|
|
*q++ = p->value;
|
|
p = p->next;
|
|
}
|
|
*q++ = -1;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
print_derives();
|
|
#endif
|
|
|
|
FREE(dset + ntokens);
|
|
FREE(delts);
|
|
}
|
|
|
|
void
|
|
free_derives()
|
|
{
|
|
FREE(derives[ntokens]);
|
|
FREE(derives + ntokens);
|
|
}
|
|
|
|
|
|
|
|
#ifdef DEBUG
|
|
|
|
print_derives()
|
|
{
|
|
register int i;
|
|
register short *sp;
|
|
|
|
extern char **tags;
|
|
|
|
printf("\n\n\nDERIVES\n\n");
|
|
|
|
for (i = ntokens; i < nsyms; i++)
|
|
{
|
|
printf("%s derives", tags[i]);
|
|
for (sp = derives[i]; *sp > 0; sp++)
|
|
{
|
|
printf(" %d", *sp);
|
|
}
|
|
putchar('\n');
|
|
}
|
|
|
|
putchar('\n');
|
|
}
|
|
|
|
#endif
|
|
|