Copy BYacc's nice way to report the grammar.

[bison.git] / src / print.c

/* Print information on generated parser, for bison,
   Copyright (C) 1984, 1986, 1989, 2000, 2001, 2002
   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 "quotearg.h"
#include "files.h"
#include "symtab.h"
#include "gram.h"
#include "LR0.h"
#include "lalr.h"
#include "conflicts.h"
#include "getargs.h"
#include "state.h"
#include "reader.h"
#include "print.h"
#include "reduce.h"
#include "closure.h"
#include "bitset.h"

static bitset shiftset;
static bitset lookaheadset;

#if 0
static void
print_token (int extnum, int token)
{
  fprintf (out, _(" type %d is %s\n"), extnum, tags[token]);
}
#endif

\f
/*--------------------------------.
| Report information on a state.  |
`--------------------------------*/

static void
print_core (FILE *out, state_t *state)
{
  int i;
  item_number_t *sitems = state->items;
  int snritems   = state->nitems;

  /* Output all the items of a state, not only its kernel.  */
  if (report_flag & report_itemsets)
    {
      closure (sitems, snritems);
      sitems = itemset;
      snritems = nritemset;
    }

  if (snritems)
    {
      for (i = 0; i < snritems; i++)
	{
	  item_number_t *sp;
	  item_number_t *sp1;
	  int rule;

	  sp1 = sp = ritem + sitems[i];

	  while (*sp >= 0)
	    sp++;

	  rule = -(*sp);
	  fprintf (out, "    %s  ->  ", symbol_tag_get (rules[rule].lhs));

	  for (sp = rules[rule].rhs; sp < sp1; sp++)
	    fprintf (out, "%s ", symbol_tag_get (symbols[*sp]));

	  fputc ('.', out);

	  for (/* Nothing */; *sp >= 0; ++sp)
	    fprintf (out, " %s", symbol_tag_get (symbols[*sp]));

	  /* Display the lookaheads?  */
	  if (report_flag & report_lookaheads)
	    {
	      int j, k;
	      int nlookaheads = 0;
	      /* Look for lookaheads corresponding to this rule. */
	      for (j = 0; j < state->nlookaheads; ++j)
		for (k = 0; k < ntokens; ++k)
		  if (bitset_test (LA[state->lookaheadsp + j], k)
		      && LArule[state->lookaheadsp + j]->number == rule)
		    nlookaheads++;
	      if (nlookaheads)
		{
		  fprintf (out, "  [");
		  for (j = 0; j < state->nlookaheads; ++j)
		    for (k = 0; k < ntokens; ++k)
		      if (bitset_test (LA[state->lookaheadsp + j], k)
			  && LArule[state->lookaheadsp + j]->number == rule)
			fprintf (out, "%s%s",
				 symbol_tag_get (symbols[k]),
				 --nlookaheads ? ", " : "");
		  fprintf (out, "]");
		}
	    }

	  fprintf (out, _("   (rule %d)"), rule - 1);
	  fputc ('\n', out);
	}

      fputc ('\n', out);
    }
}


static void
print_shifts (FILE *out, state_t *state)
{
  int i;
  shifts *shiftp = state->shifts;

  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
    if (!SHIFT_IS_DISABLED (shiftp, i))
      {
	int state1 = shiftp->shifts[i];
	symbol_number_t symbol = states[state1]->accessing_symbol;
	fprintf (out,
		 _("    %-4s\tshift, and go to state %d\n"),
		 symbol_tag_get (symbols[symbol]), state1);
      }

  if (i > 0)
    fputc ('\n', out);
}


static void
print_errs (FILE *out, state_t *state)
{
  errs *errp = state->errs;
  int i;

  for (i = 0; i < errp->nerrs; ++i)
    if (errp->errs[i])
      fprintf (out, _("    %-4s\terror (nonassociative)\n"),
	       symbol_tag_get (symbols[errp->errs[i]]));

  if (i > 0)
    fputc ('\n', out);
}


static void
print_gotos (FILE *out, state_t *state)
{
  int i;
  shifts *shiftp = state->shifts;

  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
    /* Skip token shifts.  */;

  if (i < shiftp->nshifts)
    {
      for (; i < shiftp->nshifts; i++)
	if (!SHIFT_IS_DISABLED (shiftp, i))
	  {
	    int state1 = shiftp->shifts[i];
	    symbol_number_t symbol = states[state1]->accessing_symbol;
	    fprintf (out, _("    %-4s\tgo to state %d\n"),
		     symbol_tag_get (symbols[symbol]), state1);
	  }

      fputc ('\n', out);
    }
}

static void
print_reductions (FILE *out, state_t *state)
{
  int i;
  shifts *shiftp = state->shifts;
  reductions *redp = state->reductions;
  errs *errp = state->errs;
  int nodefault = 0;

  if (redp->nreds == 0)
    return;

  if (state->consistent)
    {
      int rule = redp->rules[0];
      symbol_number_t symbol = rules[rule].lhs->number;
      fprintf (out, _("    $default\treduce using rule %d (%s)\n\n"),
	       rule - 1, symbol_tag_get (symbols[symbol]));
      return;
    }

  bitset_zero (shiftset);

  for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
    if (!SHIFT_IS_DISABLED (shiftp, i))
      {
	/* if this state has a shift for the error token, don't use a
	   default rule.  */
	if (SHIFT_IS_ERROR (shiftp, i))
	  nodefault = 1;
	bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i));
      }

  for (i = 0; i < errp->nerrs; i++)
    if (errp->errs[i])
      bitset_set (shiftset, errp->errs[i]);

  if (state->nlookaheads == 1 && !nodefault)
    {
      rule_t *default_rule = LArule[state->lookaheadsp];

      bitset_and (lookaheadset, LA[state->lookaheadsp], shiftset);

      for (i = 0; i < ntokens; i++)
	if (bitset_test (lookaheadset, i))
	  fprintf (out, _("    %-4s\t[reduce using rule %d (%s)]\n"),
		   symbol_tag_get (symbols[i]),
		   default_rule->number - 1,
		   symbol_tag_get_n (default_rule->lhs, 1));

      fprintf (out, _("    $default\treduce using rule %d (%s)\n\n"),
	       default_rule->number - 1,
	       symbol_tag_get (default_rule->lhs));
    }
  else if (state->nlookaheads >= 1)
    {
      int cmax = 0;
      int default_LA = -1;
      rule_t *default_rule = NULL;

      if (!nodefault)
	for (i = 0; i < state->nlookaheads; ++i)
	  {
	    int count = 0;
	    int j;

	    bitset_andn (lookaheadset, LA[state->lookaheadsp + i], shiftset);

	    for (j = 0; j < ntokens; j++)
	      if (bitset_test (lookaheadset, j))
		count++;

	    if (count > cmax)
	      {
		cmax = count;
		default_LA = state->lookaheadsp + i;
		default_rule = LArule[state->lookaheadsp + i];
	      }

	    bitset_or (shiftset, shiftset, lookaheadset);
	  }

      bitset_zero (shiftset);

      for (i = 0; i < shiftp->nshifts && SHIFT_IS_SHIFT (shiftp, i); i++)
	if (!SHIFT_IS_DISABLED (shiftp, i))
	  bitset_set (shiftset, SHIFT_SYMBOL (shiftp, i));

      for (i = 0; i < ntokens; i++)
	{
	  int j;
	  int defaulted = 0;
	  int count = bitset_test (shiftset, i);

	  for (j = 0; j < state->nlookaheads; ++j)
	    if (bitset_test (LA[state->lookaheadsp + j], i))
	      {
		if (count == 0)
		  {
		    if (state->lookaheadsp + j != default_LA)
		      fprintf (out,
			       _("    %-4s\treduce using rule %d (%s)\n"),
			       symbol_tag_get (symbols[i]),
			       LArule[state->lookaheadsp + j]->number - 1,
			       symbol_tag_get_n (LArule[state->lookaheadsp + j]->lhs, 1));
		    else
		      defaulted = 1;

		    count++;
		  }
		else
		  {
		    if (defaulted)
		      fprintf (out,
			       _("    %-4s\treduce using rule %d (%s)\n"),
			       symbol_tag_get (symbols[i]),
			       LArule[default_LA]->number - 1,
			       symbol_tag_get_n (LArule[default_LA]->lhs, 1));
		    defaulted = 0;
		    fprintf (out,
			     _("    %-4s\t[reduce using rule %d (%s)]\n"),
			     symbol_tag_get (symbols[i]),
			     LArule[state->lookaheadsp + j]->number - 1,
			     symbol_tag_get_n (LArule[state->lookaheadsp + j]->lhs, 1));
		  }
	      }
	}

      if (default_LA >= 0)
	fprintf (out, _("    $default\treduce using rule %d (%s)\n"),
		 default_rule->number - 1,
		 symbol_tag_get (default_rule->lhs));
    }
}


static void
print_actions (FILE *out, state_t *state)
{
  reductions *redp = state->reductions;
  shifts *shiftp = state->shifts;

  if (shiftp->nshifts == 0 && redp->nreds == 0)
    {
      if (final_state == state->number)
       fprintf (out, _("    $default\taccept\n"));
      else
       fprintf (out, _("    NO ACTIONS\n"));
      return;
    }

  print_shifts (out, state);
  print_errs (out, state);
  print_reductions (out, state);
  print_gotos (out, state);
}

static void
print_state (FILE *out, state_t *state)
{
  fprintf (out, _("state %d"), state->number);
  fputs ("\n\n", out);
  print_core (out, state);
  print_actions (out, state);
  if ((report_flag & report_solved_conflicts)
      && state->solved_conflicts)
    fputs (state->solved_conflicts, out);
  fputs ("\n\n", out);
}
\f
/*-----------------------------------------.
| Print information on the whole grammar.  |
`-----------------------------------------*/

#define END_TEST(End)				\
do {						\
  if (column + strlen(buffer) > (End))		\
    {						\
      fprintf (out, "%s\n   ", buffer);		\
      column = 3;				\
      buffer[0] = 0;				\
    }						\
} while (0)


static void
print_grammar (FILE *out)
{
  symbol_number_t i;
  item_number_t *rule;
  char buffer[90];
  int column = 0;

  grammar_rules_print (out);

  /* TERMINAL (type #) : rule #s terminal is on RHS */
  fprintf (out, "%s\n\n", _("Terminals, with rules where they appear"));
  for (i = 0; i < max_user_token_number + 1; i++)
    if (token_translations[i] != undeftoken->number)
      {
	const char *tag = symbol_tag_get (symbols[token_translations[i]]);
	int r;
	buffer[0] = 0;
	column = strlen (tag);
	fputs (tag, out);
	END_TEST (50);
	sprintf (buffer, " (%d)", i);

	for (r = 1; r < nrules + 1; r++)
	  for (rule = rules[r].rhs; *rule >= 0; rule++)
	    if (item_number_as_symbol_number (*rule) == token_translations[i])
	      {
		END_TEST (65);
		sprintf (buffer + strlen (buffer), " %d", r - 1);
		break;
	      }
	fprintf (out, "%s\n", buffer);
      }
  fputs ("\n\n", out);


  fprintf (out, "%s\n\n", _("Nonterminals, with rules where they appear"));
  for (i = ntokens; i < nsyms; i++)
    {
      int left_count = 0, right_count = 0;
      int r;
      const char *tag = symbol_tag_get (symbols[i]);

      for (r = 1; r < nrules + 1; r++)
	{
	  if (rules[r].lhs->number == i)
	    left_count++;
	  for (rule = rules[r].rhs; *rule >= 0; rule++)
	    if (item_number_as_symbol_number (*rule) == i)
	      {
		right_count++;
		break;
	      }
	}

      buffer[0] = 0;
      fputs (tag, out);
      column = strlen (tag);
      sprintf (buffer, " (%d)", i);
      END_TEST (0);

      if (left_count > 0)
	{
	  END_TEST (50);
	  sprintf (buffer + strlen (buffer), _(" on left:"));

	  for (r = 1; r < nrules + 1; r++)
	    {
	      END_TEST (65);
	      if (rules[r].lhs->number == i)
		sprintf (buffer + strlen (buffer), " %d", r - 1);
	    }
	}

      if (right_count > 0)
	{
	  if (left_count > 0)
	    sprintf (buffer + strlen (buffer), ",");
	  END_TEST (50);
	  sprintf (buffer + strlen (buffer), _(" on right:"));
	  for (r = 1; r < nrules + 1; r++)
	    {
	      for (rule = rules[r].rhs; *rule >= 0; rule++)
		if (item_number_as_symbol_number (*rule) == i)
		  {
		    END_TEST (65);
		    sprintf (buffer + strlen (buffer), " %d", r - 1);
		    break;
		  }
	    }
	}
      fprintf (out, "%s\n", buffer);
    }
  fputs ("\n\n", out);
}
\f
void
print_results (void)
{
  size_t i;

  /* We used to use just .out if SPEC_NAME_PREFIX (-p) was used, but
     that conflicts with Posix.  */
  FILE *out = xfopen (spec_verbose_file, "w");

  reduce_output (out);
  conflicts_output (out);

  print_grammar (out);

  /* If the whole state item sets, not only the kernels, are wanted,
     `closure' will be run, which needs memory allocation/deallocation.   */
  if (report_flag & report_itemsets)
    new_closure (nritems);
  /* Storage for print_reductions.  */
  shiftset =  bitset_create (ntokens, BITSET_FIXED);
  lookaheadset = bitset_create (ntokens, BITSET_FIXED);
  for (i = 0; i < nstates; i++)
    print_state (out, states[i]);
  bitset_free (shiftset);
  bitset_free (lookaheadset);
  if (report_flag & report_itemsets)
    free_closure ();

  xfclose (out);
}