tag.c

   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
  58 tag_alloc(void)
  59 {
  60         mandoc_ohash_init(&tag_data, 4, offsetof(struct tag_entry, s));
  61 }
  62
  63 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
  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
 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
 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
 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
 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 }