bison/src/print_graph.c

/* Output a VCG description on generated parser, for Bison,
   Copyright 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 "xalloc.h"
#include "files.h"
#include "gram.h"
#include "LR0.h"
#include "lalr.h"
#include "conflicts.h"
#include "complain.h"
#include "getargs.h"
#include "state.h"
#include "reader.h"
#include "obstack.h"
#include "print_graph.h"
#include "vcg.h"
#include "quote.h"

static graph_t graph;

/* This part will construct the label of nodes. */
static void
print_core (int state)
{
  int i;
  int k;
  int rule;
  core *statep;
  short *sp;
  short *sp1;

  statep = state_table[state];
  k = statep->nitems;

  if (k == 0)
    return;

  obstack_sgrow (&graph_obstack, "\t\tlabel:\t\"");

  for (i = 0; i < k; i++)
    {
      if (i)
	obstack_sgrow (&graph_obstack, "\\n");

      sp1 = sp = ritem + statep->items[i];

      while (*sp > 0)
	sp++;

      rule = -(*sp);

      obstack_fgrow1 (&graph_obstack, _("%d: "), rule);
      obstack_fgrow1 (&graph_obstack, " %s  ->  ", quote (tags[rlhs[rule]]));

      for (sp = ritem + rrhs[rule]; sp < sp1; sp++)
	obstack_fgrow1 (&graph_obstack, "%s ", quote (tags[*sp]));

      obstack_1grow (&graph_obstack, '.');

      while (*sp > 0)
	obstack_fgrow1 (&graph_obstack, " %s", quote (tags[*sp++]));

    }
  obstack_sgrow (&graph_obstack, "\"\n");
}

static void
print_actions (int state, node_t *node)
{
  int i;
  int k;
  int state1;
  int symbol;
  shifts *shiftp;
  errs *errp;
  reductions *redp;
  int rule;
  static char buff[10];
  edge_t edge;

  shiftp = shift_table[state];
  redp = reduction_table[state];
  errp = err_table[state];

  if (!shiftp && !redp)
    {
#if 0
      if (final_state == state)
	fprintf (f, "    $default\taccept\n");
      else
	fprintf (f, "    NO ACTIONS\n");
#endif
      return;
    }

  if (shiftp)
    {
      k = shiftp->nshifts;

      for (i = 0; i < k; i++)
	{
	  if (!shiftp->shifts[i])
	    continue;
	  state1 = shiftp->shifts[i];
	  symbol = accessing_symbol[state1];

	  if (ISVAR (symbol))
	    break;

	  {
	    new_edge (&edge);

	    if (state > state1)
	      edge.type = back_edge;
	    open_edge (&edge, &graph_obstack);
	    edge.sourcename = node->title;
	    sprintf (buff, "%d", state1);
	    edge.targetname = buff;
	    edge.color = (symbol == 0) ? blue : red;
	    /* FIXME: Be aware that quote uses static memory.  The string
	       must be output immediately (which is the case here). */
	    edge.label = tags[symbol] ? quote (tags[symbol]) : NULL;
	    output_edge (&edge, &graph_obstack);
	    close_edge (&graph_obstack);
	  }
	}
    }
  else
    {
      i = 0;
      k = 0;
    }

  if (errp)
    {
      int j, nerrs;

      nerrs = errp->nerrs;

      for (j = 0; j < nerrs; j++)
	{
	  if (!errp->errs[j])
	    continue;
	  symbol = errp->errs[j];
	}
    }

  if (consistent[state] && redp)
    {
      rule = redp->rules[0];
      symbol = rlhs[rule];
    }

  if (i < k)
    {
      for (; i < k; i++)
	{
	  if (!shiftp->shifts[i])
	    continue;
	  state1 = shiftp->shifts[i];
	  symbol = accessing_symbol[state1];

	  new_edge (&edge);
	  open_edge (&edge, &graph_obstack);
	  edge.sourcename = node->title;
	  sprintf (buff, "%d", state1);
	  edge.targetname = buff;
	  edge.color = red;
	  edge.label = tags[symbol] ? quote (tags[symbol]) : NULL;
	  output_edge (&edge, &graph_obstack);
	  close_edge (&graph_obstack);
	}
    }
}

static void
print_state (int state)
{
  static char name[10];
  node_t node;

  new_node (&node);
  open_node (&graph_obstack);

  sprintf (name, "%d", state);
  node.title = name;
  output_node (&node, &graph_obstack);

  print_core (state);		/* node label */

  close_node (&graph_obstack);

  print_actions (state, &node);	/* edges */
}


void
print_graph (void)
{
  int i;

  if (!graph_flag)
    return;
  new_graph (&graph);

  /* graph.smanhattan_edges = yes;
     graph.manhattan_edges = yes; */

  graph.display_edge_labels = yes;
  graph.layoutalgorithm = 0;

  graph.port_sharing = no;
  graph.finetuning = yes;
  graph.straight_phase = yes;
  graph.priority_phase = yes;
  graph.splines = yes;

  graph.crossing_weight = median;

  /* Output graph options. */
  open_graph (&graph_obstack);
  output_graph (&graph, &graph_obstack);

  for (i = 0; i < nstates; i++)
    /* Output nodes & edges. */
    print_state (i);

  /* Close graph. */
  close_graph (&graph, &graph_obstack);
}