1 /* $Id: tag.c,v 1.36 2020/04/19 16:36:16 schwarze Exp $ */
2 /*
3 * Copyright (c) 2015,2016,2018,2019,2020 Ingo Schwarze <schwarze@openbsd.org>
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 *
17 * Functions to tag syntax tree nodes.
18 * For internal use by mandoc(1) validation modules only.
19 */
20 #include "config.h"
21
22 #include <sys/types.h>
23
24 #include <assert.h>
25 #include <limits.h>
26 #include <stddef.h>
27 #include <stdint.h>
28 #include <stdlib.h>
29 #include <string.h>
30
31 #include "mandoc_aux.h"
32 #include "mandoc_ohash.h"
33 #include "roff.h"
34 #include "mdoc.h"
35 #include "roff_int.h"
36 #include "tag.h"
37
38 struct tag_entry {
39 struct roff_node **nodes;
40 size_t maxnodes;
41 size_t nnodes;
42 int prio;
43 char s[];
44 };
45
46 static void tag_move_href(struct roff_man *,
47 struct roff_node *, const char *);
48 static void tag_move_id(struct roff_node *);
49
50 static struct ohash tag_data;
51
52
53 /*
54 * Set up the ohash table to collect nodes
55 * where various marked-up terms are documented.
56 */
57 void
tag_alloc(void)58 tag_alloc(void)
59 {
60 mandoc_ohash_init(&tag_data, 4, offsetof(struct tag_entry, s));
61 }
62
63 void
tag_free(void)64 tag_free(void)
65 {
66 struct tag_entry *entry;
67 unsigned int slot;
68
69 if (tag_data.info.free == NULL)
70 return;
71 entry = ohash_first(&tag_data, &slot);
72 while (entry != NULL) {
73 free(entry->nodes);
74 free(entry);
75 entry = ohash_next(&tag_data, &slot);
76 }
77 ohash_delete(&tag_data);
78 tag_data.info.free = NULL;
79 }
80
81 /*
82 * Set a node where a term is defined,
83 * unless it is already defined at a lower priority.
84 */
85 void
tag_put(const char * s,int prio,struct roff_node * n)86 tag_put(const char *s, int prio, struct roff_node *n)
87 {
88 struct tag_entry *entry;
89 struct roff_node *nold;
90 const char *se;
91 size_t len;
92 unsigned int slot;
93
94 assert(prio <= TAG_FALLBACK);
95
96 if (s == NULL) {
97 if (n->child == NULL || n->child->type != ROFFT_TEXT)
98 return;
99 s = n->child->string;
100 switch (s[0]) {
101 case '-':
102 s++;
103 break;
104 case '\\':
105 switch (s[1]) {
106 case '&':
107 case '-':
108 case 'e':
109 s += 2;
110 break;
111 default:
112 break;
113 }
114 break;
115 default:
116 break;
117 }
118 }
119
120 /*
121 * Skip whitespace and escapes and whatever follows,
122 * and if there is any, downgrade the priority.
123 */
124
125 len = strcspn(s, " \t\\");
126 if (len == 0)
127 return;
128
129 se = s + len;
130 if (*se != '\0' && prio < TAG_WEAK)
131 prio = TAG_WEAK;
132
133 slot = ohash_qlookupi(&tag_data, s, &se);
134 entry = ohash_find(&tag_data, slot);
135
136 /* Build a new entry. */
137
138 if (entry == NULL) {
139 entry = mandoc_malloc(sizeof(*entry) + len + 1);
140 memcpy(entry->s, s, len);
141 entry->s[len] = '\0';
142 entry->nodes = NULL;
143 entry->maxnodes = entry->nnodes = 0;
144 ohash_insert(&tag_data, slot, entry);
145 }
146
147 /*
148 * Lower priority numbers take precedence.
149 * If a better entry is already present, ignore the new one.
150 */
151
152 else if (entry->prio < prio)
153 return;
154
155 /*
156 * If the existing entry is worse, clear it.
157 * In addition, a tag with priority TAG_FALLBACK
158 * is only used if the tag occurs exactly once.
159 */
160
161 else if (entry->prio > prio || prio == TAG_FALLBACK) {
162 while (entry->nnodes > 0) {
163 nold = entry->nodes[--entry->nnodes];
164 nold->flags &= ~NODE_ID;
165 free(nold->tag);
166 nold->tag = NULL;
167 }
168 if (prio == TAG_FALLBACK) {
169 entry->prio = TAG_DELETE;
170 return;
171 }
172 }
173
174 /* Remember the new node. */
175
176 if (entry->maxnodes == entry->nnodes) {
177 entry->maxnodes += 4;
178 entry->nodes = mandoc_reallocarray(entry->nodes,
179 entry->maxnodes, sizeof(*entry->nodes));
180 }
181 entry->nodes[entry->nnodes++] = n;
182 entry->prio = prio;
183 n->flags |= NODE_ID;
184 if (n->child == NULL || n->child->string != s || *se != '\0') {
185 assert(n->tag == NULL);
186 n->tag = mandoc_strndup(s, len);
187 }
188 }
189
190 int
tag_exists(const char * tag)191 tag_exists(const char *tag)
192 {
193 return ohash_find(&tag_data, ohash_qlookup(&tag_data, tag)) != NULL;
194 }
195
196 /*
197 * For in-line elements, move the link target
198 * to the enclosing paragraph when appropriate.
199 */
200 static void
tag_move_id(struct roff_node * n)201 tag_move_id(struct roff_node *n)
202 {
203 struct roff_node *np;
204
205 np = n;
206 for (;;) {
207 if (np->prev != NULL)
208 np = np->prev;
209 else if ((np = np->parent) == NULL)
210 return;
211 switch (np->tok) {
212 case MDOC_It:
213 switch (np->parent->parent->norm->Bl.type) {
214 case LIST_column:
215 /* Target the ROFFT_BLOCK = <tr>. */
216 np = np->parent;
217 break;
218 case LIST_diag:
219 case LIST_hang:
220 case LIST_inset:
221 case LIST_ohang:
222 case LIST_tag:
223 /* Target the ROFFT_HEAD = <dt>. */
224 np = np->parent->head;
225 break;
226 default:
227 /* Target the ROFF_BODY = <li>. */
228 break;
229 }
230 /* FALLTHROUGH */
231 case MDOC_Pp: /* Target the ROFFT_ELEM = <p>. */
232 if (np->tag == NULL) {
233 np->tag = mandoc_strdup(n->tag == NULL ?
234 n->child->string : n->tag);
235 np->flags |= NODE_ID;
236 n->flags &= ~NODE_ID;
237 }
238 return;
239 case MDOC_Sh:
240 case MDOC_Ss:
241 case MDOC_Bd:
242 case MDOC_Bl:
243 case MDOC_D1:
244 case MDOC_Dl:
245 case MDOC_Rs:
246 /* Do not move past major blocks. */
247 return;
248 default:
249 /*
250 * Move past in-line content and partial
251 * blocks, for example .It Xo or .It Bq Er.
252 */
253 break;
254 }
255 }
256 }
257
258 /*
259 * When a paragraph is tagged and starts with text,
260 * move the permalink to the first few words.
261 */
262 static void
tag_move_href(struct roff_man * man,struct roff_node * n,const char * tag)263 tag_move_href(struct roff_man *man, struct roff_node *n, const char *tag)
264 {
265 char *cp;
266
267 if (n == NULL || n->type != ROFFT_TEXT ||
268 *n->string == '\0' || *n->string == ' ')
269 return;
270
271 cp = n->string;
272 while (cp != NULL && cp - n->string < 5)
273 cp = strchr(cp + 1, ' ');
274
275 /* If the first text node is longer, split it. */
276
277 if (cp != NULL && cp[1] != '\0') {
278 man->last = n;
279 man->next = ROFF_NEXT_SIBLING;
280 roff_word_alloc(man, n->line,
281 n->pos + (cp - n->string), cp + 1);
282 man->last->flags = n->flags & ~NODE_LINE;
283 *cp = '\0';
284 }
285
286 assert(n->tag == NULL);
287 n->tag = mandoc_strdup(tag);
288 n->flags |= NODE_HREF;
289 }
290
291 /*
292 * When all tags have been set, decide where to put
293 * the associated permalinks, and maybe move some tags
294 * to the beginning of the respective paragraphs.
295 */
296 void
tag_postprocess(struct roff_man * man,struct roff_node * n)297 tag_postprocess(struct roff_man *man, struct roff_node *n)
298 {
299 if (n->flags & NODE_ID) {
300 switch (n->tok) {
301 case MDOC_Pp:
302 tag_move_href(man, n->next, n->tag);
303 break;
304 case MDOC_Bd:
305 case MDOC_D1:
306 case MDOC_Dl:
307 tag_move_href(man, n->child, n->tag);
308 break;
309 case MDOC_Bl:
310 /* XXX No permalink for now. */
311 break;
312 default:
313 if (n->type == ROFFT_ELEM || n->tok == MDOC_Fo)
314 tag_move_id(n);
315 if (n->tok != MDOC_Tg)
316 n->flags |= NODE_HREF;
317 else if ((n->flags & NODE_ID) == 0) {
318 n->flags |= NODE_NOPRT;
319 free(n->tag);
320 n->tag = NULL;
321 }
322 break;
323 }
324 }
325 for (n = n->child; n != NULL; n = n->next)
326 tag_postprocess(man, n);
327 }
328