html.c

   1 /* $Id: html.c,v 1.275 2021/09/09 14:47:24 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2011-2015, 2017-2021 Ingo Schwarze <schwarze@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHORS DISCLAIM ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  * Common functions for mandoc(1) HTML formatters.
  19  * For use by individual formatters and by the main program.
  20  */
  21 #include "config.h"
  22
  23 #include <sys/types.h>
  24 #include <sys/stat.h>
  25
  26 #include <assert.h>
  27 #include <ctype.h>
  28 #include <stdarg.h>
  29 #include <stddef.h>
  30 #include <stdio.h>
  31 #include <stdint.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <unistd.h>
  35
  36 #include "mandoc_aux.h"
  37 #include "mandoc_ohash.h"
  38 #include "mandoc.h"
  39 #include "roff.h"
  40 #include "out.h"
  41 #include "html.h"
  42 #include "manconf.h"
  43 #include "main.h"
  44
  45 struct  htmldata {
  46         const char       *name;
  47         int               flags;
  48 #define HTML_INPHRASE    (1 << 0)  /* Can appear in phrasing context. */
  49 #define HTML_TOPHRASE    (1 << 1)  /* Establishes phrasing context. */
  50 #define HTML_NOSTACK     (1 << 2)  /* Does not have an end tag. */
  51 #define HTML_NLBEFORE    (1 << 3)  /* Output line break before opening. */
  52 #define HTML_NLBEGIN     (1 << 4)  /* Output line break after opening. */
  53 #define HTML_NLEND       (1 << 5)  /* Output line break before closing. */
  54 #define HTML_NLAFTER     (1 << 6)  /* Output line break after closing. */
  55 #define HTML_NLAROUND    (HTML_NLBEFORE | HTML_NLAFTER)
  56 #define HTML_NLINSIDE    (HTML_NLBEGIN | HTML_NLEND)
  57 #define HTML_NLALL       (HTML_NLAROUND | HTML_NLINSIDE)
  58 #define HTML_INDENT      (1 << 7)  /* Indent content by two spaces. */
  59 #define HTML_NOINDENT    (1 << 8)  /* Exception: never indent content. */
  60 };
  61
  62 static  const struct htmldata htmltags[TAG_MAX] = {
  63         {"html",        HTML_NLALL},
  64         {"head",        HTML_NLALL | HTML_INDENT},
  65         {"meta",        HTML_NOSTACK | HTML_NLALL},
  66         {"link",        HTML_NOSTACK | HTML_NLALL},
  67         {"style",       HTML_NLALL | HTML_INDENT},
  68         {"title",       HTML_NLAROUND},
  69         {"body",        HTML_NLALL},
  70         {"div",         HTML_NLAROUND},
  71         {"section",     HTML_NLALL},
  72         {"table",       HTML_NLALL | HTML_INDENT},
  73         {"tr",          HTML_NLALL | HTML_INDENT},
  74         {"td",          HTML_NLAROUND},
  75         {"li",          HTML_NLAROUND | HTML_INDENT},
  76         {"ul",          HTML_NLALL | HTML_INDENT},
  77         {"ol",          HTML_NLALL | HTML_INDENT},
  78         {"dl",          HTML_NLALL | HTML_INDENT},
  79         {"dt",          HTML_NLAROUND},
  80         {"dd",          HTML_NLAROUND | HTML_INDENT},
  81         {"h1",          HTML_TOPHRASE | HTML_NLAROUND},
  82         {"h2",          HTML_TOPHRASE | HTML_NLAROUND},
  83         {"p",           HTML_TOPHRASE | HTML_NLAROUND | HTML_INDENT},
  84         {"pre",         HTML_TOPHRASE | HTML_NLAROUND | HTML_NOINDENT},
  85         {"a",           HTML_INPHRASE | HTML_TOPHRASE},
  86         {"b",           HTML_INPHRASE | HTML_TOPHRASE},
  87         {"cite",        HTML_INPHRASE | HTML_TOPHRASE},
  88         {"code",        HTML_INPHRASE | HTML_TOPHRASE},
  89         {"i",           HTML_INPHRASE | HTML_TOPHRASE},
  90         {"small",       HTML_INPHRASE | HTML_TOPHRASE},
  91         {"span",        HTML_INPHRASE | HTML_TOPHRASE},
  92         {"var",         HTML_INPHRASE | HTML_TOPHRASE},
  93         {"br",          HTML_INPHRASE | HTML_NOSTACK | HTML_NLALL},
  94         {"hr",          HTML_INPHRASE | HTML_NOSTACK},
  95         {"mark",        HTML_INPHRASE },
  96         {"math",        HTML_INPHRASE | HTML_NLALL | HTML_INDENT},
  97         {"mrow",        0},
  98         {"mi",          0},
  99         {"mn",          0},
 100         {"mo",          0},
 101         {"msup",        0},
 102         {"msub",        0},
 103         {"msubsup",     0},
 104         {"mfrac",       0},
 105         {"msqrt",       0},
 106         {"mfenced",     0},
 107         {"mtable",      0},
 108         {"mtr",         0},
 109         {"mtd",         0},
 110         {"munderover",  0},
 111         {"munder",      0},
 112         {"mover",       0},
 113 };
 114
 115 /* Avoid duplicate HTML id= attributes. */
 116
 117 struct  id_entry {
 118         int      ord;   /* Ordinal number of the latest occurrence. */
 119         char     id[];  /* The id= attribute without any ordinal suffix. */
 120 };
 121 static  struct ohash     id_unique;
 122
 123 static  void     html_reset_internal(struct html *);
 124 static  void     print_byte(struct html *, char);
 125 static  void     print_endword(struct html *);
 126 static  void     print_indent(struct html *);
 127 static  void     print_word(struct html *, const char *);
 128
 129 static  void     print_ctag(struct html *, struct tag *);
 130 static  int      print_escape(struct html *, char);
 131 static  int      print_encode(struct html *, const char *, const char *, int);
 132 static  void     print_href(struct html *, const char *, const char *, int);
 133 static  void     print_metaf(struct html *);
 134
 135
 136 void *
 137 html_alloc(const struct manoutput *outopts)
 138 {
 139         struct html     *h;
 140
 141         h = mandoc_calloc(1, sizeof(struct html));
 142
 143         h->tag = NULL;
 144         h->metac = h->metal = ESCAPE_FONTROMAN;
 145         h->style = outopts->style;
 146         if ((h->base_man1 = outopts->man) == NULL)
 147                 h->base_man2 = NULL;
 148         else if ((h->base_man2 = strchr(h->base_man1, ';')) != NULL)
 149                 *h->base_man2++ = '\0';
 150         h->base_includes = outopts->includes;
 151         if (outopts->fragment)
 152                 h->oflags |= HTML_FRAGMENT;
 153         if (outopts->toc)
 154                 h->oflags |= HTML_TOC;
 155
 156         mandoc_ohash_init(&id_unique, 4, offsetof(struct id_entry, id));
 157
 158         return h;
 159 }
 160
 161 static void
 162 html_reset_internal(struct html *h)
 163 {
 164         struct tag      *tag;
 165         struct id_entry *entry;
 166         unsigned int     slot;
 167
 168         while ((tag = h->tag) != NULL) {
 169                 h->tag = tag->next;
 170                 free(tag);
 171         }
 172         entry = ohash_first(&id_unique, &slot);
 173         while (entry != NULL) {
 174                 free(entry);
 175                 entry = ohash_next(&id_unique, &slot);
 176         }
 177         ohash_delete(&id_unique);
 178 }
 179
 180 void
 181 html_reset(void *p)
 182 {
 183         html_reset_internal(p);
 184         mandoc_ohash_init(&id_unique, 4, offsetof(struct id_entry, id));
 185 }
 186
 187 void
 188 html_free(void *p)
 189 {
 190         html_reset_internal(p);
 191         free(p);
 192 }
 193
 194 void
 195 print_gen_head(struct html *h)
 196 {
 197         struct tag      *t;
 198
 199         print_otag(h, TAG_META, "?", "charset", "utf-8");
 200         print_otag(h, TAG_META, "??", "name", "viewport",
 201             "content", "width=device-width, initial-scale=1.0");
 202         if (h->style != NULL) {
 203                 print_otag(h, TAG_LINK, "?h??", "rel", "stylesheet",
 204                     h->style, "type", "text/css", "media", "all");
 205                 return;
 206         }
 207
 208         /*
 209          * Print a minimal embedded style sheet.
 210          */
 211
 212         t = print_otag(h, TAG_STYLE, "");
 213         print_text(h, "table.head, table.foot { width: 100%; }");
 214         print_endline(h);
 215         print_text(h, "td.head-rtitle, td.foot-os { text-align: right; }");
 216         print_endline(h);
 217         print_text(h, "td.head-vol { text-align: center; }");
 218         print_endline(h);
 219         print_text(h, ".Nd, .Bf, .Op { display: inline; }");
 220         print_endline(h);
 221         print_text(h, ".Pa, .Ad { font-style: italic; }");
 222         print_endline(h);
 223         print_text(h, ".Ms { font-weight: bold; }");
 224         print_endline(h);
 225         print_text(h, ".Bl-diag ");
 226         print_byte(h, '>');
 227         print_text(h, " dt { font-weight: bold; }");
 228         print_endline(h);
 229         print_text(h, "code.Nm, .Fl, .Cm, .Ic, code.In, .Fd, .Fn, .Cd "
 230             "{ font-weight: bold; font-family: inherit; }");
 231         print_tagq(h, t);
 232 }
 233
 234 int
 235 html_setfont(struct html *h, enum mandoc_esc font)
 236 {
 237         switch (font) {
 238         case ESCAPE_FONTPREV:
 239                 font = h->metal;
 240                 break;
 241         case ESCAPE_FONTITALIC:
 242         case ESCAPE_FONTBOLD:
 243         case ESCAPE_FONTBI:
 244         case ESCAPE_FONTROMAN:
 245         case ESCAPE_FONTCR:
 246         case ESCAPE_FONTCB:
 247         case ESCAPE_FONTCI:
 248                 break;
 249         case ESCAPE_FONT:
 250                 font = ESCAPE_FONTROMAN;
 251                 break;
 252         default:
 253                 return 0;
 254         }
 255         h->metal = h->metac;
 256         h->metac = font;
 257         return 1;
 258 }
 259
 260 static void
 261 print_metaf(struct html *h)
 262 {
 263         if (h->metaf) {
 264                 print_tagq(h, h->metaf);
 265                 h->metaf = NULL;
 266         }
 267         switch (h->metac) {
 268         case ESCAPE_FONTITALIC:
 269                 h->metaf = print_otag(h, TAG_I, "");
 270                 break;
 271         case ESCAPE_FONTBOLD:
 272                 h->metaf = print_otag(h, TAG_B, "");
 273                 break;
 274         case ESCAPE_FONTBI:
 275                 h->metaf = print_otag(h, TAG_B, "");
 276                 print_otag(h, TAG_I, "");
 277                 break;
 278         case ESCAPE_FONTCR:
 279                 h->metaf = print_otag(h, TAG_SPAN, "c", "Li");
 280                 break;
 281         case ESCAPE_FONTCB:
 282                 h->metaf = print_otag(h, TAG_SPAN, "c", "Li");
 283                 print_otag(h, TAG_B, "");
 284                 break;
 285         case ESCAPE_FONTCI:
 286                 h->metaf = print_otag(h, TAG_SPAN, "c", "Li");
 287                 print_otag(h, TAG_I, "");
 288                 break;
 289         default:
 290                 break;
 291         }
 292 }
 293
 294 void
 295 html_close_paragraph(struct html *h)
 296 {
 297         struct tag      *this, *next;
 298         int              flags;
 299
 300         this = h->tag;
 301         for (;;) {
 302                 next = this->next;
 303                 flags = htmltags[this->tag].flags;
 304                 if (flags & (HTML_INPHRASE | HTML_TOPHRASE))
 305                         print_ctag(h, this);
 306                 if ((flags & HTML_INPHRASE) == 0)
 307                         break;
 308                 this = next;
 309         }
 310 }
 311
 312 /*
 313  * ROFF_nf switches to no-fill mode, ROFF_fi to fill mode.
 314  * TOKEN_NONE does not switch.  The old mode is returned.
 315  */
 316 enum roff_tok
 317 html_fillmode(struct html *h, enum roff_tok want)
 318 {
 319         struct tag      *t;
 320         enum roff_tok    had;
 321
 322         for (t = h->tag; t != NULL; t = t->next)
 323                 if (t->tag == TAG_PRE)
 324                         break;
 325
 326         had = t == NULL ? ROFF_fi : ROFF_nf;
 327
 328         if (want != had) {
 329                 switch (want) {
 330                 case ROFF_fi:
 331                         print_tagq(h, t);
 332                         break;
 333                 case ROFF_nf:
 334                         html_close_paragraph(h);
 335                         print_otag(h, TAG_PRE, "");
 336                         break;
 337                 case TOKEN_NONE:
 338                         break;
 339                 default:
 340                         abort();
 341                 }
 342         }
 343         return had;
 344 }
 345
 346 /*
 347  * Allocate a string to be used for the "id=" attribute of an HTML
 348  * element and/or as a segment identifier for a URI in an <a> element.
 349  * The function may fail and return NULL if the node lacks text data
 350  * to create the attribute from.
 351  * The caller is responsible for free(3)ing the returned string.
 352  *
 353  * If the "unique" argument is non-zero, the "id_unique" ohash table
 354  * is used for de-duplication.  If the "unique" argument is 1,
 355  * it is the first time the function is called for this tag and
 356  * location, so if an ordinal suffix is needed, it is incremented.
 357  * If the "unique" argument is 2, it is the second time the function
 358  * is called for this tag and location, so the ordinal suffix
 359  * remains unchanged.
 360  */
 361 char *
 362 html_make_id(const struct roff_node *n, int unique)
 363 {
 364         const struct roff_node  *nch;
 365         struct id_entry         *entry;
 366         char                    *buf, *cp;
 367         size_t                   len;
 368         unsigned int             slot;
 369
 370         if (n->tag != NULL)
 371                 buf = mandoc_strdup(n->tag);
 372         else {
 373                 switch (n->tok) {
 374                 case MDOC_Sh:
 375                 case MDOC_Ss:
 376                 case MDOC_Sx:
 377                 case MAN_SH:
 378                 case MAN_SS:
 379                         for (nch = n->child; nch != NULL; nch = nch->next)
 380                                 if (nch->type != ROFFT_TEXT)
 381                                         return NULL;
 382                         buf = NULL;
 383                         deroff(&buf, n);
 384                         if (buf == NULL)
 385                                 return NULL;
 386                         break;
 387                 default:
 388                         if (n->child == NULL || n->child->type != ROFFT_TEXT)
 389                                 return NULL;
 390                         buf = mandoc_strdup(n->child->string);
 391                         break;
 392                 }
 393         }
 394
 395         /*
 396          * In ID attributes, only use ASCII characters that are
 397          * permitted in URL-fragment strings according to the
 398          * explicit list at:
 399          * https://url.spec.whatwg.org/#url-fragment-string
 400          * In addition, reserve '~' for ordinal suffixes.
 401          */
 402
 403         for (cp = buf; *cp != '\0'; cp++)
 404                 if (isalnum((unsigned char)*cp) == 0 &&
 405                     strchr("!$&'()*+,-./:;=?@_", *cp) == NULL)
 406                         *cp = '_';
 407
 408         if (unique == 0)
 409                 return buf;
 410
 411         /* Avoid duplicate HTML id= attributes. */
 412
 413         slot = ohash_qlookup(&id_unique, buf);
 414         if ((entry = ohash_find(&id_unique, slot)) == NULL) {
 415                 len = strlen(buf) + 1;
 416                 entry = mandoc_malloc(sizeof(*entry) + len);
 417                 entry->ord = 1;
 418                 memcpy(entry->id, buf, len);
 419                 ohash_insert(&id_unique, slot, entry);
 420         } else if (unique == 1)
 421                 entry->ord++;
 422
 423         if (entry->ord > 1) {
 424                 cp = buf;
 425                 mandoc_asprintf(&buf, "%s~%d", cp, entry->ord);
 426                 free(cp);
 427         }
 428         return buf;
 429 }
 430
 431 static int
 432 print_escape(struct html *h, char c)
 433 {
 434
 435         switch (c) {
 436         case '<':
 437                 print_word(h, "&lt;");
 438                 break;
 439         case '>':
 440                 print_word(h, "&gt;");
 441                 break;
 442         case '&':
 443                 print_word(h, "&amp;");
 444                 break;
 445         case '"':
 446                 print_word(h, "&quot;");
 447                 break;
 448         case ASCII_NBRSP:
 449                 print_word(h, "&nbsp;");
 450                 break;
 451         case ASCII_HYPH:
 452                 print_byte(h, '-');
 453                 break;
 454         case ASCII_BREAK:
 455                 break;
 456         default:
 457                 return 0;
 458         }
 459         return 1;
 460 }
 461
 462 static int
 463 print_encode(struct html *h, const char *p, const char *pend, int norecurse)
 464 {
 465         char             numbuf[16];
 466         const char      *seq;
 467         size_t           sz;
 468         int              c, len, breakline, nospace;
 469         enum mandoc_esc  esc;
 470         static const char rejs[10] = { ' ', '\\', '<', '>', '&', '"',
 471                 ASCII_NBRSP, ASCII_HYPH, ASCII_BREAK, '\0' };
 472
 473         if (pend == NULL)
 474                 pend = strchr(p, '\0');
 475
 476         breakline = 0;
 477         nospace = 0;
 478
 479         while (p < pend) {
 480                 if (HTML_SKIPCHAR & h->flags && '\\' != *p) {
 481                         h->flags &= ~HTML_SKIPCHAR;
 482                         p++;
 483                         continue;
 484                 }
 485
 486                 for (sz = strcspn(p, rejs); sz-- && p < pend; p++)
 487                         print_byte(h, *p);
 488
 489                 if (breakline &&
 490                     (p >= pend || *p == ' ' || *p == ASCII_NBRSP)) {
 491                         print_otag(h, TAG_BR, "");
 492                         breakline = 0;
 493                         while (p < pend && (*p == ' ' || *p == ASCII_NBRSP))
 494                                 p++;
 495                         continue;
 496                 }
 497
 498                 if (p >= pend)
 499                         break;
 500
 501                 if (*p == ' ') {
 502                         print_endword(h);
 503                         p++;
 504                         continue;
 505                 }
 506
 507                 if (print_escape(h, *p++))
 508                         continue;
 509
 510                 esc = mandoc_escape(&p, &seq, &len);
 511                 switch (esc) {
 512                 case ESCAPE_FONT:
 513                 case ESCAPE_FONTPREV:
 514                 case ESCAPE_FONTBOLD:
 515                 case ESCAPE_FONTITALIC:
 516                 case ESCAPE_FONTBI:
 517                 case ESCAPE_FONTROMAN:
 518                 case ESCAPE_FONTCR:
 519                 case ESCAPE_FONTCB:
 520                 case ESCAPE_FONTCI:
 521                         if (0 == norecurse) {
 522                                 h->flags |= HTML_NOSPACE;
 523                                 if (html_setfont(h, esc))
 524                                         print_metaf(h);
 525                                 h->flags &= ~HTML_NOSPACE;
 526                         }
 527                         continue;
 528                 case ESCAPE_SKIPCHAR:
 529                         h->flags |= HTML_SKIPCHAR;
 530                         continue;
 531                 case ESCAPE_ERROR:
 532                         continue;
 533                 default:
 534                         break;
 535                 }
 536
 537                 if (h->flags & HTML_SKIPCHAR) {
 538                         h->flags &= ~HTML_SKIPCHAR;
 539                         continue;
 540                 }
 541
 542                 switch (esc) {
 543                 case ESCAPE_UNICODE:
 544                         /* Skip past "u" header. */
 545                         c = mchars_num2uc(seq + 1, len - 1);
 546                         break;
 547                 case ESCAPE_NUMBERED:
 548                         c = mchars_num2char(seq, len);
 549                         if (c < 0)
 550                                 continue;
 551                         break;
 552                 case ESCAPE_SPECIAL:
 553                         c = mchars_spec2cp(seq, len);
 554                         if (c <= 0)
 555                                 continue;
 556                         break;
 557                 case ESCAPE_UNDEF:
 558                         c = *seq;
 559                         break;
 560                 case ESCAPE_DEVICE:
 561                         print_word(h, "html");
 562                         continue;
 563                 case ESCAPE_BREAK:
 564                         breakline = 1;
 565                         continue;
 566                 case ESCAPE_NOSPACE:
 567                         if ('\0' == *p)
 568                                 nospace = 1;
 569                         continue;
 570                 case ESCAPE_OVERSTRIKE:
 571                         if (len == 0)
 572                                 continue;
 573                         c = seq[len - 1];
 574                         break;
 575                 default:
 576                         continue;
 577                 }
 578                 if ((c < 0x20 && c != 0x09) ||
 579                     (c > 0x7E && c < 0xA0))
 580                         c = 0xFFFD;
 581                 if (c > 0x7E) {
 582                         (void)snprintf(numbuf, sizeof(numbuf), "&#x%.4X;", c);
 583                         print_word(h, numbuf);
 584                 } else if (print_escape(h, c) == 0)
 585                         print_byte(h, c);
 586         }
 587
 588         return nospace;
 589 }
 590
 591 static void
 592 print_href(struct html *h, const char *name, const char *sec, int man)
 593 {
 594         struct stat      sb;
 595         const char      *p, *pp;
 596         char            *filename;
 597
 598         if (man) {
 599                 pp = h->base_man1;
 600                 if (h->base_man2 != NULL) {
 601                         mandoc_asprintf(&filename, "%s.%s", name, sec);
 602                         if (stat(filename, &sb) == -1)
 603                                 pp = h->base_man2;
 604                         free(filename);
 605                 }
 606         } else
 607                 pp = h->base_includes;
 608
 609         while ((p = strchr(pp, '%')) != NULL) {
 610                 print_encode(h, pp, p, 1);
 611                 if (man && p[1] == 'S') {
 612                         if (sec == NULL)
 613                                 print_byte(h, '1');
 614                         else
 615                                 print_encode(h, sec, NULL, 1);
 616                 } else if ((man && p[1] == 'N') ||
 617                     (man == 0 && p[1] == 'I'))
 618                         print_encode(h, name, NULL, 1);
 619                 else
 620                         print_encode(h, p, p + 2, 1);
 621                 pp = p + 2;
 622         }
 623         if (*pp != '\0')
 624                 print_encode(h, pp, NULL, 1);
 625 }
 626
 627 struct tag *
 628 print_otag(struct html *h, enum htmltag tag, const char *fmt, ...)
 629 {
 630         va_list          ap;
 631         struct tag      *t;
 632         const char      *attr;
 633         char            *arg1, *arg2;
 634         int              style_written, tflags;
 635
 636         tflags = htmltags[tag].flags;
 637
 638         /* Flow content is not allowed in phrasing context. */
 639
 640         if ((tflags & HTML_INPHRASE) == 0) {
 641                 for (t = h->tag; t != NULL; t = t->next) {
 642                         if (t->closed)
 643                                 continue;
 644                         assert((htmltags[t->tag].flags & HTML_TOPHRASE) == 0);
 645                         break;
 646                 }
 647
 648         /*
 649          * Always wrap phrasing elements in a paragraph
 650          * unless already contained in some flow container;
 651          * never put them directly into a section.
 652          */
 653
 654         } else if (tflags & HTML_TOPHRASE && h->tag->tag == TAG_SECTION)
 655                 print_otag(h, TAG_P, "c", "Pp");
 656
 657         /* Push this tag onto the stack of open scopes. */
 658
 659         if ((tflags & HTML_NOSTACK) == 0) {
 660                 t = mandoc_malloc(sizeof(struct tag));
 661                 t->tag = tag;
 662                 t->next = h->tag;
 663                 t->refcnt = 0;
 664                 t->closed = 0;
 665                 h->tag = t;
 666         } else
 667                 t = NULL;
 668
 669         if (tflags & HTML_NLBEFORE)
 670                 print_endline(h);
 671         if (h->col == 0)
 672                 print_indent(h);
 673         else if ((h->flags & HTML_NOSPACE) == 0) {
 674                 if (h->flags & HTML_KEEP)
 675                         print_word(h, "&#x00A0;");
 676                 else {
 677                         if (h->flags & HTML_PREKEEP)
 678                                 h->flags |= HTML_KEEP;
 679                         print_endword(h);
 680                 }
 681         }
 682
 683         if ( ! (h->flags & HTML_NONOSPACE))
 684                 h->flags &= ~HTML_NOSPACE;
 685         else
 686                 h->flags |= HTML_NOSPACE;
 687
 688         /* Print out the tag name and attributes. */
 689
 690         print_byte(h, '<');
 691         print_word(h, htmltags[tag].name);
 692
 693         va_start(ap, fmt);
 694
 695         while (*fmt != '\0' && *fmt != 's') {
 696
 697                 /* Parse attributes and arguments. */
 698
 699                 arg1 = va_arg(ap, char *);
 700                 arg2 = NULL;
 701                 switch (*fmt++) {
 702                 case 'c':
 703                         attr = "class";
 704                         break;
 705                 case 'h':
 706                         attr = "href";
 707                         break;
 708                 case 'i':
 709                         attr = "id";
 710                         break;
 711                 case '?':
 712                         attr = arg1;
 713                         arg1 = va_arg(ap, char *);
 714                         break;
 715                 default:
 716                         abort();
 717                 }
 718                 if (*fmt == 'M')
 719                         arg2 = va_arg(ap, char *);
 720                 if (arg1 == NULL)
 721                         continue;
 722
 723                 /* Print the attributes. */
 724
 725                 print_byte(h, ' ');
 726                 print_word(h, attr);
 727                 print_byte(h, '=');
 728                 print_byte(h, '"');
 729                 switch (*fmt) {
 730                 case 'I':
 731                         print_href(h, arg1, NULL, 0);
 732                         fmt++;
 733                         break;
 734                 case 'M':
 735                         print_href(h, arg1, arg2, 1);
 736                         fmt++;
 737                         break;
 738                 case 'R':
 739                         print_byte(h, '#');
 740                         print_encode(h, arg1, NULL, 1);
 741                         fmt++;
 742                         break;
 743                 default:
 744                         print_encode(h, arg1, NULL, 1);
 745                         break;
 746                 }
 747                 print_byte(h, '"');
 748         }
 749
 750         style_written = 0;
 751         while (*fmt++ == 's') {
 752                 arg1 = va_arg(ap, char *);
 753                 arg2 = va_arg(ap, char *);
 754                 if (arg2 == NULL)
 755                         continue;
 756                 print_byte(h, ' ');
 757                 if (style_written == 0) {
 758                         print_word(h, "style=\"");
 759                         style_written = 1;
 760                 }
 761                 print_word(h, arg1);
 762                 print_byte(h, ':');
 763                 print_byte(h, ' ');
 764                 print_word(h, arg2);
 765                 print_byte(h, ';');
 766         }
 767         if (style_written)
 768                 print_byte(h, '"');
 769
 770         va_end(ap);
 771
 772         /* Accommodate for "well-formed" singleton escaping. */
 773
 774         if (htmltags[tag].flags & HTML_NOSTACK)
 775                 print_byte(h, '/');
 776
 777         print_byte(h, '>');
 778
 779         if (tflags & HTML_NLBEGIN)
 780                 print_endline(h);
 781         else
 782                 h->flags |= HTML_NOSPACE;
 783
 784         if (tflags & HTML_INDENT)
 785                 h->indent++;
 786         if (tflags & HTML_NOINDENT)
 787                 h->noindent++;
 788
 789         return t;
 790 }
 791
 792 /*
 793  * Print an element with an optional "id=" attribute.
 794  * If the element has phrasing content and an "id=" attribute,
 795  * also add a permalink: outside if it can be in phrasing context,
 796  * inside otherwise.
 797  */
 798 struct tag *
 799 print_otag_id(struct html *h, enum htmltag elemtype, const char *cattr,
 800     struct roff_node *n)
 801 {
 802         struct roff_node *nch;
 803         struct tag      *ret, *t;
 804         char            *id, *href;
 805
 806         ret = NULL;
 807         id = href = NULL;
 808         if (n->flags & NODE_ID)
 809                 id = html_make_id(n, 1);
 810         if (n->flags & NODE_HREF)
 811                 href = id == NULL ? html_make_id(n, 2) : id;
 812         if (href != NULL && htmltags[elemtype].flags & HTML_INPHRASE)
 813                 ret = print_otag(h, TAG_A, "chR", "permalink", href);
 814         t = print_otag(h, elemtype, "ci", cattr, id);
 815         if (ret == NULL) {
 816                 ret = t;
 817                 if (href != NULL && (nch = n->child) != NULL) {
 818                         /* man(7) is safe, it tags phrasing content only. */
 819                         if (n->tok > MDOC_MAX ||
 820                             htmltags[elemtype].flags & HTML_TOPHRASE)
 821                                 nch = NULL;
 822                         else  /* For mdoc(7), beware of nested blocks. */
 823                                 while (nch != NULL && nch->type == ROFFT_TEXT)
 824                                         nch = nch->next;
 825                         if (nch == NULL)
 826                                 print_otag(h, TAG_A, "chR", "permalink", href);
 827                 }
 828         }
 829         free(id);
 830         if (id == NULL)
 831                 free(href);
 832         return ret;
 833 }
 834
 835 static void
 836 print_ctag(struct html *h, struct tag *tag)
 837 {
 838         int      tflags;
 839
 840         if (tag->closed == 0) {
 841                 tag->closed = 1;
 842                 if (tag == h->metaf)
 843                         h->metaf = NULL;
 844                 if (tag == h->tblt)
 845                         h->tblt = NULL;
 846
 847                 tflags = htmltags[tag->tag].flags;
 848                 if (tflags & HTML_INDENT)
 849                         h->indent--;
 850                 if (tflags & HTML_NOINDENT)
 851                         h->noindent--;
 852                 if (tflags & HTML_NLEND)
 853                         print_endline(h);
 854                 print_indent(h);
 855                 print_byte(h, '<');
 856                 print_byte(h, '/');
 857                 print_word(h, htmltags[tag->tag].name);
 858                 print_byte(h, '>');
 859                 if (tflags & HTML_NLAFTER)
 860                         print_endline(h);
 861         }
 862         if (tag->refcnt == 0) {
 863                 h->tag = tag->next;
 864                 free(tag);
 865         }
 866 }
 867
 868 void
 869 print_gen_decls(struct html *h)
 870 {
 871         print_word(h, "<!DOCTYPE html>");
 872         print_endline(h);
 873 }
 874
 875 void
 876 print_gen_comment(struct html *h, struct roff_node *n)
 877 {
 878         int      wantblank;
 879
 880         print_word(h, "<!-- This is an automatically generated file."
 881             "  Do not edit.");
 882         h->indent = 1;
 883         wantblank = 0;
 884         while (n != NULL && n->type == ROFFT_COMMENT) {
 885                 if (strstr(n->string, "-->") == NULL &&
 886                     (wantblank || *n->string != '\0')) {
 887                         print_endline(h);
 888                         print_indent(h);
 889                         print_word(h, n->string);
 890                         wantblank = *n->string != '\0';
 891                 }
 892                 n = n->next;
 893         }
 894         if (wantblank)
 895                 print_endline(h);
 896         print_word(h, " -->");
 897         print_endline(h);
 898         h->indent = 0;
 899 }
 900
 901 void
 902 print_text(struct html *h, const char *word)
 903 {
 904         print_tagged_text(h, word, NULL);
 905 }
 906
 907 void
 908 print_tagged_text(struct html *h, const char *word, struct roff_node *n)
 909 {
 910         struct tag      *t;
 911         char            *href;
 912
 913         /*
 914          * Always wrap text in a paragraph unless already contained in
 915          * some flow container; never put it directly into a section.
 916          */
 917
 918         if (h->tag->tag == TAG_SECTION)
 919                 print_otag(h, TAG_P, "c", "Pp");
 920
 921         /* Output whitespace before this text? */
 922
 923         if (h->col && (h->flags & HTML_NOSPACE) == 0) {
 924                 if ( ! (HTML_KEEP & h->flags)) {
 925                         if (HTML_PREKEEP & h->flags)
 926                                 h->flags |= HTML_KEEP;
 927                         print_endword(h);
 928                 } else
 929                         print_word(h, "&#x00A0;");
 930         }
 931
 932         /*
 933          * Optionally switch fonts, optionally write a permalink, then
 934          * print the text, optionally surrounded by HTML whitespace.
 935          */
 936
 937         assert(h->metaf == NULL);
 938         print_metaf(h);
 939         print_indent(h);
 940
 941         if (n != NULL && (href = html_make_id(n, 2)) != NULL) {
 942                 t = print_otag(h, TAG_A, "chR", "permalink", href);
 943                 free(href);
 944         } else
 945                 t = NULL;
 946
 947         if ( ! print_encode(h, word, NULL, 0)) {
 948                 if ( ! (h->flags & HTML_NONOSPACE))
 949                         h->flags &= ~HTML_NOSPACE;
 950                 h->flags &= ~HTML_NONEWLINE;
 951         } else
 952                 h->flags |= HTML_NOSPACE | HTML_NONEWLINE;
 953
 954         if (h->metaf != NULL) {
 955                 print_tagq(h, h->metaf);
 956                 h->metaf = NULL;
 957         } else if (t != NULL)
 958                 print_tagq(h, t);
 959
 960         h->flags &= ~HTML_IGNDELIM;
 961 }
 962
 963 void
 964 print_tagq(struct html *h, const struct tag *until)
 965 {
 966         struct tag      *this, *next;
 967
 968         for (this = h->tag; this != NULL; this = next) {
 969                 next = this == until ? NULL : this->next;
 970                 print_ctag(h, this);
 971         }
 972 }
 973
 974 /*
 975  * Close out all open elements up to but excluding suntil.
 976  * Note that a paragraph just inside stays open together with it
 977  * because paragraphs include subsequent phrasing content.
 978  */
 979 void
 980 print_stagq(struct html *h, const struct tag *suntil)
 981 {
 982         struct tag      *this, *next;
 983
 984         for (this = h->tag; this != NULL; this = next) {
 985                 next = this->next;
 986                 if (this == suntil || (next == suntil &&
 987                     (this->tag == TAG_P || this->tag == TAG_PRE)))
 988                         break;
 989                 print_ctag(h, this);
 990         }
 991 }
 992
 993
 994 /***********************************************************************
 995  * Low level output functions.
 996  * They implement line breaking using a short static buffer.
 997  ***********************************************************************/
 998
 999 /*
1000  * Buffer one HTML output byte.
1001  * If the buffer is full, flush and deactivate it and start a new line.
1002  * If the buffer is inactive, print directly.
1003  */
1004 static void
1005 print_byte(struct html *h, char c)
1006 {
1007         if ((h->flags & HTML_BUFFER) == 0) {
1008                 putchar(c);
1009                 h->col++;
1010                 return;
1011         }
1012
1013         if (h->col + h->bufcol < sizeof(h->buf)) {
1014                 h->buf[h->bufcol++] = c;
1015                 return;
1016         }
1017
1018         putchar('\n');
1019         h->col = 0;
1020         print_indent(h);
1021         putchar(' ');
1022         putchar(' ');
1023         fwrite(h->buf, h->bufcol, 1, stdout);
1024         putchar(c);
1025         h->col = (h->indent + 1) * 2 + h->bufcol + 1;
1026         h->bufcol = 0;
1027         h->flags &= ~HTML_BUFFER;
1028 }
1029
1030 /*
1031  * If something was printed on the current output line, end it.
1032  * Not to be called right after print_indent().
1033  */
1034 void
1035 print_endline(struct html *h)
1036 {
1037         if (h->col == 0)
1038                 return;
1039
1040         if (h->bufcol) {
1041                 putchar(' ');
1042                 fwrite(h->buf, h->bufcol, 1, stdout);
1043                 h->bufcol = 0;
1044         }
1045         putchar('\n');
1046         h->col = 0;
1047         h->flags |= HTML_NOSPACE;
1048         h->flags &= ~HTML_BUFFER;
1049 }
1050
1051 /*
1052  * Flush the HTML output buffer.
1053  * If it is inactive, activate it.
1054  */
1055 static void
1056 print_endword(struct html *h)
1057 {
1058         if (h->noindent) {
1059                 print_byte(h, ' ');
1060                 return;
1061         }
1062
1063         if ((h->flags & HTML_BUFFER) == 0) {
1064                 h->col++;
1065                 h->flags |= HTML_BUFFER;
1066         } else if (h->bufcol) {
1067                 putchar(' ');
1068                 fwrite(h->buf, h->bufcol, 1, stdout);
1069                 h->col += h->bufcol + 1;
1070         }
1071         h->bufcol = 0;
1072 }
1073
1074 /*
1075  * If at the beginning of a new output line,
1076  * perform indentation and mark the line as containing output.
1077  * Make sure to really produce some output right afterwards,
1078  * but do not use print_otag() for producing it.
1079  */
1080 static void
1081 print_indent(struct html *h)
1082 {
1083         size_t   i;
1084
1085         if (h->col || h->noindent)
1086                 return;
1087
1088         h->col = h->indent * 2;
1089         for (i = 0; i < h->col; i++)
1090                 putchar(' ');
1091 }
1092
1093 /*
1094  * Print or buffer some characters
1095  * depending on the current HTML output buffer state.
1096  */
1097 static void
1098 print_word(struct html *h, const char *cp)
1099 {
1100         while (*cp != '\0')
1101                 print_byte(h, *cp++);
1102 }