bin/mandoc/preconv.c

   1 /*      $Id: preconv.c,v 1.17 2018/12/13 11:55:47 schwarze Exp $ */
   2 /*
   3  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
   4  * Copyright (c) 2014 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 AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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 #include "config.h"
  19
  20 #include <sys/types.h>
  21
  22 #include <assert.h>
  23 #include <stdio.h>
  24 #include <string.h>
  25
  26 #include "mandoc.h"
  27 #include "roff.h"
  28 #include "mandoc_parse.h"
  29 #include "libmandoc.h"
  30
  31 int
  32 preconv_encode(const struct buf *ib, size_t *ii, struct buf *ob, size_t *oi,
  33     int *filenc)
  34 {
  35         const unsigned char     *cu;
  36         int                      nby;
  37         unsigned int             accum;
  38
  39         cu = (const unsigned char *)ib->buf + *ii;
  40         assert(*cu & 0x80);
  41
  42         if ( ! (*filenc & MPARSE_UTF8))
  43                 goto latin;
  44
  45         nby = 1;
  46         while (nby < 5 && *cu & (1 << (7 - nby)))
  47                 nby++;
  48
  49         switch (nby) {
  50         case 2:
  51                 accum = *cu & 0x1f;
  52                 if (accum < 0x02)  /* Obfuscated ASCII. */
  53                         goto latin;
  54                 break;
  55         case 3:
  56                 accum = *cu & 0x0f;
  57                 break;
  58         case 4:
  59                 accum = *cu & 0x07;
  60                 if (accum > 0x04) /* Beyond Unicode. */
  61                         goto latin;
  62                 break;
  63         default:  /* Bad sequence header. */
  64                 goto latin;
  65         }
  66
  67         cu++;
  68         switch (nby) {
  69         case 3:
  70                 if ((accum == 0x00 && ! (*cu & 0x20)) ||  /* Use 2-byte. */
  71                     (accum == 0x0d && *cu & 0x20))  /* Surrogates. */
  72                         goto latin;
  73                 break;
  74         case 4:
  75                 if ((accum == 0x00 && ! (*cu & 0x30)) ||  /* Use 3-byte. */
  76                     (accum == 0x04 && *cu & 0x30))  /* Beyond Unicode. */
  77                         goto latin;
  78                 break;
  79         default:
  80                 break;
  81         }
  82
  83         while (--nby) {
  84                 if ((*cu & 0xc0) != 0x80)  /* Invalid continuation. */
  85                         goto latin;
  86                 accum <<= 6;
  87                 accum += *cu & 0x3f;
  88                 cu++;
  89         }
  90
  91         assert(accum > 0x7f);
  92         assert(accum < 0x110000);
  93         assert(accum < 0xd800 || accum > 0xdfff);
  94
  95         *oi += snprintf(ob->buf + *oi, 11, "\\[u%.4X]", accum);
  96         *ii = (const char *)cu - ib->buf;
  97         *filenc &= ~MPARSE_LATIN1;
  98         return 1;
  99
 100 latin:
 101         if ( ! (*filenc & MPARSE_LATIN1))
 102                 return 0;
 103
 104         *oi += snprintf(ob->buf + *oi, 11,
 105             "\\[u%.4X]", (unsigned char)ib->buf[(*ii)++]);
 106
 107         *filenc &= ~MPARSE_UTF8;
 108         return 1;
 109 }
 110
 111 int
 112 preconv_cue(const struct buf *b, size_t offset)
 113 {
 114         const char      *ln, *eoln, *eoph;
 115         size_t           sz, phsz;
 116
 117         ln = b->buf + offset;
 118         sz = b->sz - offset;
 119
 120         /* Look for the end-of-line. */
 121
 122         if (NULL == (eoln = memchr(ln, '\n', sz)))
 123                 eoln = ln + sz;
 124
 125         /* Check if we have the correct header/trailer. */
 126
 127         if ((sz = (size_t)(eoln - ln)) < 10 ||
 128             memcmp(ln, ".\\\" -*-", 7) || memcmp(eoln - 3, "-*-", 3))
 129                 return MPARSE_UTF8 | MPARSE_LATIN1;
 130
 131         /* Move after the header and adjust for the trailer. */
 132
 133         ln += 7;
 134         sz -= 10;
 135
 136         while (sz > 0) {
 137                 while (sz > 0 && ' ' == *ln) {
 138                         ln++;
 139                         sz--;
 140                 }
 141                 if (0 == sz)
 142                         break;
 143
 144                 /* Find the end-of-phrase marker (or eoln). */
 145
 146                 if (NULL == (eoph = memchr(ln, ';', sz)))
 147                         eoph = eoln - 3;
 148                 else
 149                         eoph++;
 150
 151                 /* Only account for the "coding" phrase. */
 152
 153                 if ((phsz = eoph - ln) < 7 ||
 154                     strncasecmp(ln, "coding:", 7)) {
 155                         sz -= phsz;
 156                         ln += phsz;
 157                         continue;
 158                 }
 159
 160                 sz -= 7;
 161                 ln += 7;
 162
 163                 while (sz > 0 && ' ' == *ln) {
 164                         ln++;
 165                         sz--;
 166                 }
 167                 if (0 == sz)
 168                         return 0;
 169
 170                 /* Check us against known encodings. */
 171
 172                 if (phsz > 4 && !strncasecmp(ln, "utf-8", 5))
 173                         return MPARSE_UTF8;
 174                 if (phsz > 10 && !strncasecmp(ln, "iso-latin-1", 11))
 175                         return MPARSE_LATIN1;
 176                 return 0;
 177         }
 178         return MPARSE_UTF8 | MPARSE_LATIN1;
 179 }