src/derives.c

/* Match rules with nonterminals for bison,
   Copyright 1984, 1989, 2000, 2001  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, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */


#include "system.h"
#include "getargs.h"
#include "types.h"
#include "reader.h"
#include "gram.h"
#include "derives.h"

short **derives = NULL;

static void
print_derives (void)
{
  int i;

  fputs ("DERIVES\n", stderr);

  for (i = ntokens; i < nsyms; i++)
    {
      short *sp;
      fprintf (stderr, "\t%s derives\n", tags[i]);
      for (sp = derives[i]; *sp > 0; sp++)
	{
	  short *rhsp;
	  fprintf (stderr, "\t\t%d:", *sp);
	  for (rhsp = ritem + rule_table[*sp].rhs; *rhsp > 0; ++rhsp)
	    fprintf (stderr, " %s", tags[*rhsp]);
	  fprintf (stderr, " (rule %d)\n", -*rhsp);
	}
    }

  fputs ("\n\n", stderr);
}


void
set_derives (void)
{
  int i;
  shorts *p;
  short *q;
  shorts **dset;
  shorts *delts;

  dset = XCALLOC (shorts *, nvars) - ntokens;
  delts = XCALLOC (shorts, nrules + 1);

  p = delts;
  for (i = nrules; i > 0; i--)
    if (rule_table[i].useful)
      {
	int lhs = rule_table[i].lhs;
	p->next = dset[lhs];
	p->value = i;
	dset[lhs] = p;
	p++;
      }

  derives = XCALLOC (short *, nvars) - ntokens;
  q = XCALLOC (short, nvars + nrules);

  for (i = ntokens; i < nsyms; i++)
    {
      derives[i] = q;
      p = dset[i];
      while (p)
	{
	  *q++ = p->value;
	  p = p->next;
	}
      *q++ = -1;
    }

  if (trace_flag)
    print_derives ();

  XFREE (dset + ntokens);
  XFREE (delts);
}

void
free_derives (void)
{
  XFREE (derives[ntokens]);
  XFREE (derives + ntokens);
}
Commit	Line	Data
	1	/* Match rules with nonterminals for bison,
	2	Copyright 1984, 1989, 2000, 2001 Free Software Foundation, Inc.
	3
	4	This file is part of Bison, the GNU Compiler Compiler.
	5
	6	Bison is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2, or (at your option)
	9	any later version.
	10
	11	Bison is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with Bison; see the file COPYING. If not, write to
	18	the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	19	Boston, MA 02111-1307, USA. */
	20
	21
	22	#include "system.h"
	23	#include "getargs.h"
	24	#include "types.h"
	25	#include "reader.h"
	26	#include "gram.h"
	27	#include "derives.h"
	28
	29	short **derives = NULL;
	30
	31	static void
	32	print_derives (void)
	33	{
	34	int i;
	35
	36	fputs ("DERIVES\n", stderr);
	37
	38	for (i = ntokens; i < nsyms; i++)
	39	{
	40	short *sp;
	41	fprintf (stderr, "\t%s derives\n", tags[i]);
	42	for (sp = derives[i]; *sp > 0; sp++)
	43	{
	44	short *rhsp;
	45	fprintf (stderr, "\t\t%d:", *sp);
	46	for (rhsp = ritem + rule_table[sp].rhs; rhsp > 0; ++rhsp)
	47	fprintf (stderr, " %s", tags[*rhsp]);
	48	fprintf (stderr, " (rule %d)\n", -*rhsp);
	49	}
	50	}
	51
	52	fputs ("\n\n", stderr);
	53	}
	54
	55
	56	void
	57	set_derives (void)
	58	{
	59	int i;
	60	shorts *p;
	61	short *q;
	62	shorts **dset;
	63	shorts *delts;
	64
	65	dset = XCALLOC (shorts *, nvars) - ntokens;
	66	delts = XCALLOC (shorts, nrules + 1);
	67
	68	p = delts;
	69	for (i = nrules; i > 0; i--)
	70	if (rule_table[i].useful)
	71	{
	72	int lhs = rule_table[i].lhs;
	73	p->next = dset[lhs];
	74	p->value = i;
	75	dset[lhs] = p;
	76	p++;
	77	}
	78
	79	derives = XCALLOC (short *, nvars) - ntokens;
	80	q = XCALLOC (short, nvars + nrules);
	81
	82	for (i = ntokens; i < nsyms; i++)
	83	{
	84	derives[i] = q;
	85	p = dset[i];
	86	while (p)
	87	{
	88	*q++ = p->value;
	89	p = p->next;
	90	}
	91	*q++ = -1;
	92	}
	93
	94	if (trace_flag)
	95	print_derives ();
	96
	97	XFREE (dset + ntokens);
	98	XFREE (delts);
	99	}
	100
	101	void
	102	free_derives (void)
	103	{
	104	XFREE (derives[ntokens]);
	105	XFREE (derives + ntokens);
	106	}