aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/tools/bison/src/print-graph.c
blob: 1dd6b15e7c23652bf012f6a5e4e7158272b480de (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
/* Output a graph of the generated parser, for Bison.

   Copyright (C) 2001-2007, 2009-2015, 2018-2020 Free Software
   Foundation, Inc.

   This file is part of Bison, the GNU Compiler Compiler.

   This program 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 3 of the License, or
   (at your option) any later version.

   This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include <config.h>
#include "print-graph.h"

#include "system.h"

#include "closure.h"
#include "complain.h"
#include "conflicts.h"
#include "files.h"
#include "getargs.h"
#include "gram.h"
#include "graphviz.h"
#include "lalr.h"
#include "lr0.h"
#include "reader.h"
#include "state.h"
#include "symtab.h"


/*----------------------------.
| Construct the node labels.  |
`----------------------------*/

/* Print the lhs of a rule in such a manner that there is no vertical
   repetition, like in *.output files. */

static void
print_core (struct obstack *oout, state *s)
{
  item_number const *sitems = s->items;
  sym_content *previous_lhs = NULL;
  size_t snritems = s->nitems;

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

  obstack_printf (oout, _("State %d"), s->number);
  obstack_sgrow (oout, "\\n\\l");
  for (size_t i = 0; i < snritems; ++i)
    {
      item_number const *sp1 = ritem + sitems[i];
      rule const *r = item_rule (sp1);

      obstack_printf (oout, "%3d ", r->number);
      if (previous_lhs && UNIQSTR_EQ (previous_lhs->symbol->tag,
                                      r->lhs->symbol->tag))
        obstack_printf (oout, "%*s| ",
                        (int) strlen (previous_lhs->symbol->tag), "");
      else
        obstack_printf (oout, "%s: ", escape (r->lhs->symbol->tag));
      previous_lhs = r->lhs;

      for (item_number const *sp = r->rhs; sp < sp1; sp++)
        obstack_printf (oout, "%s ", escape (symbols[*sp]->tag));

      obstack_1grow (oout, '.');

      if (0 <= *r->rhs)
        for (item_number const *sp = sp1; 0 <= *sp; ++sp)
          obstack_printf (oout, " %s", escape (symbols[*sp]->tag));
      else
        obstack_printf (oout, " %%empty");

      /* Experimental feature: display the lookahead tokens. */
      if (report_flag & report_lookahead_tokens
          && item_number_is_rule_number (*sp1))
        {
          /* Find the reduction we are handling.  */
          reductions *reds = s->reductions;
          int redno = state_reduction_find (s, r);

          /* Print them if there are.  */
          if (reds->lookahead_tokens && redno != -1)
            {
              bitset_iterator biter;
              int k;
              char const *sep = "";
              obstack_sgrow (oout, "  [");
              BITSET_FOR_EACH (biter, reds->lookahead_tokens[redno], k, 0)
                {
                  obstack_sgrow (oout, sep);
                  obstack_sgrow (oout, escape (symbols[k]->tag));
                  sep = ", ";
                }
              obstack_1grow (oout, ']');
            }
        }
      obstack_sgrow (oout, "\\l");
    }
}


/*---------------------------------------------------------------.
| Output in graph_obstack edges specifications in incidence with |
| current node.                                                  |
`---------------------------------------------------------------*/

static void
print_actions (state const *s, FILE *fgraph)
{
  transitions const *trans = s->transitions;

  if (!trans->num && !s->reductions)
    return;

  for (int i = 0; i < trans->num; i++)
    if (!TRANSITION_IS_DISABLED (trans, i))
      {
        const state *s1 = trans->states[i];
        const symbol_number sym = s1->accessing_symbol;

        /* Shifts are solid, gotos are dashed, and error is dotted.  */
        char const *style =
          (TRANSITION_IS_ERROR (trans, i) ? "dotted"
           : TRANSITION_IS_SHIFT (trans, i) ? "solid"
           : "dashed");

        if (TRANSITION_IS_ERROR (trans, i)
            && STRNEQ (symbols[sym]->tag, "error"))
          abort ();
        output_edge (s->number, s1->number,
                     TRANSITION_IS_ERROR (trans, i) ? NULL : symbols[sym]->tag,
                     style, fgraph);
      }
  /* Display reductions. */
  output_red (s, s->reductions, fgraph);
}


/*-------------------------------------------------------------.
| Output in FGRAPH the current node specifications and exiting |
| edges.                                                       |
`-------------------------------------------------------------*/

static void
print_state (state *s, FILE *fgraph)
{
  struct obstack node_obstack;

  /* A node's label contains its items.  */
  obstack_init (&node_obstack);
  print_core (&node_obstack, s);
  output_node (s->number, obstack_finish0 (&node_obstack), fgraph);
  obstack_free (&node_obstack, 0);

  /* Output the edges.  */
  print_actions (s, fgraph);
}


void
print_graph (void)
{
  FILE *fgraph = xfopen (spec_graph_file, "w");
  start_graph (fgraph);

  /* Output nodes and edges. */
  for (int i = 0; i < nstates; i++)
    print_state (states[i], fgraph);

  finish_graph (fgraph);
  xfclose (fgraph);
}