xref: /freebsd/contrib/byacc/graph.c (revision 6b129086dcee14496517fae085b448e3edc69bc7)
1 /* $Id: graph.c,v 1.8 2014/02/19 00:46:57 Tom.Shields Exp $ */
2 
3 #include "defs.h"
4 
5 static void graph_state(int stateno);
6 static void graph_LA(int ruleno);
7 
8 static unsigned int larno;
9 
10 void
11 graph(void)
12 {
13     int i;
14     int j;
15     shifts *sp;
16     int sn;
17     int as;
18 
19     if (!gflag)
20 	return;
21 
22     for (i = 0; i < nstates; ++i)
23     {
24 	closure(state_table[i]->items, state_table[i]->nitems);
25 	graph_state(i);
26     }
27 
28     fprintf(graph_file, "\n\n");
29     for (i = 0; i < nstates; ++i)
30     {
31 
32 	sp = shift_table[i];
33 	if (sp)
34 	    for (j = 0; j < sp->nshifts; ++j)
35 	    {
36 		sn = sp->shift[j];
37 		as = accessing_symbol[sn];
38 		fprintf(graph_file,
39 			"\tq%d -> q%d [label=\"%s\"];\n",
40 			i, sn, symbol_pname[as]);
41 	    }
42     }
43 
44     fprintf(graph_file, "}\n");
45 
46     for (i = 0; i < nsyms; ++i)
47 	FREE(symbol_pname[i]);
48     FREE(symbol_pname);
49 }
50 
51 static void
52 graph_state(int stateno)
53 {
54     Value_t *isp;
55     int rule;
56     Value_t *sp;
57     Value_t *sp1;
58 
59     larno = (unsigned)lookaheads[stateno];
60     fprintf(graph_file, "\n\tq%d [label=\"%d:\\l", stateno, stateno);
61 
62     for (isp = itemset; isp < itemsetend; isp++)
63     {
64 	sp1 = sp = ritem + *isp;
65 
66 	while (*sp >= 0)
67 	    ++sp;
68 	rule = -(*sp);
69 	fprintf(graph_file, "  %s -> ", symbol_pname[rlhs[rule]]);
70 
71 	for (sp = ritem + rrhs[rule]; sp < sp1; sp++)
72 	    fprintf(graph_file, "%s ", symbol_pname[*sp]);
73 
74 	putc('.', graph_file);
75 
76 	while (*sp >= 0)
77 	{
78 	    fprintf(graph_file, " %s", symbol_pname[*sp]);
79 	    sp++;
80 	}
81 
82 	if (*sp1 < 0)
83 	    graph_LA(-*sp1);
84 
85 	fprintf(graph_file, "\\l");
86     }
87     fprintf(graph_file, "\"];");
88 }
89 
90 static void
91 graph_LA(int ruleno)
92 {
93     int i;
94     unsigned tokensetsize;
95     unsigned *rowp;
96 
97     tokensetsize = (unsigned)WORDSIZE(ntokens);
98 
99     if (ruleno == LAruleno[larno])
100     {
101 	rowp = LA + larno * tokensetsize;
102 
103 	fprintf(graph_file, " { ");
104 	for (i = ntokens - 1; i >= 0; i--)
105 	{
106 	    if (BIT(rowp, i))
107 		fprintf(graph_file, "%s ", symbol_pname[i]);
108 	}
109 	fprintf(graph_file, "}");
110 	++larno;
111     }
112 }
113