src/print_graph.c

   1 /* Output a graph of the generated parser, for Bison.
   2
   3    Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Free Software
   4    Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    Bison is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2, or (at your option)
  11    any later version.
  12
  13    Bison is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with Bison; see the file COPYING.  If not, write to
  20    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include <config.h>
  24 #include "system.h"
  25
  26 #include <quotearg.h>
  27
  28 #include "LR0.h"
  29 #include "closure.h"
  30 #include "complain.h"
  31 #include "conflicts.h"
  32 #include "files.h"
  33 #include "getargs.h"
  34 #include "gram.h"
  35 #include "graphviz.h"
  36 #include "lalr.h"
  37 #include "print_graph.h"
  38 #include "reader.h"
  39 #include "state.h"
  40 #include "symtab.h"
  41
  42
  43 /*----------------------------.
  44 | Construct the node labels.  |
  45 `----------------------------*/
  46
  47 static void
  48 print_core (struct obstack *oout, state *s)
  49 {
  50   size_t i;
  51   item_number *sitems = s->items;
  52   size_t snritems = s->nitems;
  53
  54   /* Output all the items of a state, not only its kernel.  */
  55   if (report_flag & report_itemsets)
  56     {
  57       closure (sitems, snritems);
  58       sitems = itemset;
  59       snritems = nritemset;
  60     }
  61
  62   obstack_fgrow1 (oout, "%d", s->number);
  63   for (i = 0; i < snritems; i++)
  64     {
  65       item_number *sp;
  66       item_number *sp1;
  67       rule_number r;
  68
  69       sp1 = sp = ritem + sitems[i];
  70
  71       while (*sp >= 0)
  72         sp++;
  73
  74       r = item_number_as_rule_number (*sp);
  75
  76       obstack_fgrow1 (oout, "\n%s -> ", rules[r].lhs->tag);
  77
  78       for (sp = rules[r].rhs; sp < sp1; sp++)
  79         obstack_fgrow1 (oout, "%s ", symbols[*sp]->tag);
  80
  81       obstack_1grow (oout, '.');
  82
  83       for (/* Nothing */; *sp >= 0; ++sp)
  84         obstack_fgrow1 (oout, " %s", symbols[*sp]->tag);
  85
  86       /* Experimental feature: display the lookahead tokens. */
  87       if (report_flag & report_lookahead_tokens)
  88         {
  89           /* Find the reduction we are handling.  */
  90           reductions *reds = s->reductions;
  91           int redno = state_reduction_find (s, &rules[r]);
  92
  93           /* Print them if there are.  */
  94           if (reds->lookahead_tokens && redno != -1)
  95             {
  96               bitset_iterator biter;
  97               int k;
  98               char const *sep = "";
  99               obstack_sgrow (oout, "[");
 100               BITSET_FOR_EACH (biter, reds->lookahead_tokens[redno], k, 0)
 101                 {
 102                   obstack_fgrow2 (oout, "%s%s", sep, symbols[k]->tag);
 103                   sep = ", ";
 104                 }
 105               obstack_sgrow (oout, "]");
 106             }
 107         }
 108     }
 109 }
 110
 111
 112 /*---------------------------------------------------------------.
 113 | Output in graph_obstack edges specifications in incidence with |
 114 | current node.                                                  |
 115 `---------------------------------------------------------------*/
 116
 117 static void
 118 print_actions (state const *s, FILE *fgraph)
 119 {
 120   int i;
 121
 122   transitions const *trans = s->transitions;
 123
 124   if (!trans->num && !s->reductions)
 125     return;
 126
 127   for (i = 0; i < trans->num; i++)
 128     if (!TRANSITION_IS_DISABLED (trans, i))
 129       {
 130         state *s1 = trans->states[i];
 131         symbol_number sym = s1->accessing_symbol;
 132
 133         /* Shifts are solid, gotos are dashed, and error is dotted.  */
 134         char const *style =
 135           (TRANSITION_IS_ERROR (trans, i) ? "dotted"
 136            : TRANSITION_IS_SHIFT (trans, i) ? "solid"
 137            : "dashed");
 138
 139         if (TRANSITION_IS_ERROR (trans, i)
 140             && strcmp (symbols[sym]->tag, "error") != 0)
 141           abort ();
 142         output_edge (s->number, s1->number,
 143                      TRANSITION_IS_ERROR (trans, i) ? NULL : symbols[sym]->tag,
 144                      style, fgraph);
 145       }
 146 }
 147
 148
 149 /*-------------------------------------------------------------.
 150 | Output in FGRAPH the current node specifications and exiting |
 151 | edges.                                                       |
 152 `-------------------------------------------------------------*/
 153
 154 static void
 155 print_state (state *s, FILE *fgraph)
 156 {
 157   struct obstack node_obstack;
 158
 159   /* A node's label contains its items.  */
 160   obstack_init (&node_obstack);
 161   print_core (&node_obstack, s);
 162   obstack_1grow (&node_obstack, '\0');
 163   output_node (s->number, obstack_finish (&node_obstack), fgraph);
 164   obstack_free (&node_obstack, 0);
 165
 166   /* Output the edges.  */
 167   print_actions (s, fgraph);
 168 }
 169 \f
 170
 171 void
 172 print_graph (void)
 173 {
 174   state_number i;
 175   FILE *fgraph = xfopen (spec_graph_file, "w");
 176   start_graph (fgraph);
 177
 178   /* Output nodes and edges. */
 179   new_closure (nritems);
 180   for (i = 0; i < nstates; i++)
 181     print_state (states[i], fgraph);
 182   free_closure ();
 183
 184   finish_graph (fgraph);
 185   xfclose (fgraph);
 186 }