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1 | /* Match rules with nonterminals for bison, |
2 | Copyright (C) 1984, 1989 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of Bison, the GNU Compiler Compiler. | |
5 | ||
6 | Bison is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2, or (at your option) | |
9 | any later version. | |
10 | ||
11 | Bison is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with Bison; see the file COPYING. If not, write to | |
18 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
19 | ||
20 | ||
21 | /* set_derives finds, for each variable (nonterminal), which rules can derive it. | |
22 | It sets up the value of derives so that | |
23 | derives[i - ntokens] points to a vector of rule numbers, | |
24 | terminated with -1. */ | |
25 | ||
26 | #include <stdio.h> | |
27 | #include "system.h" | |
28 | #include "new.h" | |
29 | #include "types.h" | |
30 | #include "gram.h" | |
31 | ||
32 | ||
33 | short **derives; | |
34 | ||
35 | void | |
36 | set_derives() | |
37 | { | |
38 | register int i; | |
39 | register int lhs; | |
40 | register shorts *p; | |
41 | register short *q; | |
42 | register shorts **dset; | |
43 | register shorts *delts; | |
44 | ||
45 | dset = NEW2(nvars, shorts *) - ntokens; | |
46 | delts = NEW2(nrules + 1, shorts); | |
47 | ||
48 | p = delts; | |
49 | for (i = nrules; i > 0; i--) | |
50 | { | |
51 | lhs = rlhs[i]; | |
52 | if (lhs >= 0) | |
53 | { | |
54 | p->next = dset[lhs]; | |
55 | p->value = i; | |
56 | dset[lhs] = p; | |
57 | p++; | |
58 | } | |
59 | } | |
60 | ||
61 | derives = NEW2(nvars, short *) - ntokens; | |
62 | q = NEW2(nvars + nrules, short); | |
63 | ||
64 | for (i = ntokens; i < nsyms; i++) | |
65 | { | |
66 | derives[i] = q; | |
67 | p = dset[i]; | |
68 | while (p) | |
69 | { | |
70 | *q++ = p->value; | |
71 | p = p->next; | |
72 | } | |
73 | *q++ = -1; | |
74 | } | |
75 | ||
76 | #ifdef DEBUG | |
77 | print_derives(); | |
78 | #endif | |
79 | ||
80 | FREE(dset + ntokens); | |
81 | FREE(delts); | |
82 | } | |
83 | ||
84 | void | |
85 | free_derives() | |
86 | { | |
87 | FREE(derives[ntokens]); | |
88 | FREE(derives + ntokens); | |
89 | } | |
90 | ||
91 | ||
92 | ||
93 | #ifdef DEBUG | |
94 | ||
95 | print_derives() | |
96 | { | |
97 | register int i; | |
98 | register short *sp; | |
99 | ||
100 | extern char **tags; | |
101 | ||
a083fbbf | 102 | printf(_("\n\n\nDERIVES\n\n")); |
122c0aac RS |
103 | |
104 | for (i = ntokens; i < nsyms; i++) | |
105 | { | |
a083fbbf | 106 | printf(_("%s derives"), tags[i]); |
122c0aac RS |
107 | for (sp = derives[i]; *sp > 0; sp++) |
108 | { | |
109 | printf(" %d", *sp); | |
110 | } | |
111 | putchar('\n'); | |
112 | } | |
113 | ||
114 | putchar('\n'); | |
115 | } | |
116 | ||
117 | #endif | |
118 |