tag.c

   1 /*      $Id: tag.c,v 1.10 2015/10/13 15:53:05 schwarze Exp $    */
   2 /*
   3  * Copyright (c) 2015 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 #include "config.h"
  18
  19 #include <sys/types.h>
  20
  21 #include <signal.h>
  22 #include <stddef.h>
  23 #include <stdint.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28
  29 #include "mandoc_aux.h"
  30 #include "mandoc_ohash.h"
  31 #include "tag.h"
  32
  33 struct tag_entry {
  34         size_t   line;
  35         int      prio;
  36         char     s[];
  37 };
  38
  39 static  void     tag_signal(int);
  40
  41 static struct ohash      tag_data;
  42 static struct tag_files  tag_files;
  43
  44
  45 /*
  46  * Prepare for using a pager.
  47  * Not all pagers are capable of using a tag file,
  48  * but for simplicity, create it anyway.
  49  */
  50 struct tag_files *
  51 tag_init(void)
  52 {
  53         int                      ofd;
  54
  55         ofd = -1;
  56         tag_files.tfd = -1;
  57
  58         /* Save the original standard output for use by the pager. */
  59
  60         if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1)
  61                 goto fail;
  62
  63         /* Create both temporary output files. */
  64
  65         (void)strlcpy(tag_files.ofn, "/tmp/man.XXXXXXXXXX",
  66             sizeof(tag_files.ofn));
  67         (void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
  68             sizeof(tag_files.tfn));
  69         signal(SIGHUP, tag_signal);
  70         signal(SIGINT, tag_signal);
  71         signal(SIGTERM, tag_signal);
  72         if ((ofd = mkstemp(tag_files.ofn)) == -1)
  73                 goto fail;
  74         if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1)
  75                 goto fail;
  76         if (dup2(ofd, STDOUT_FILENO) == -1)
  77                 goto fail;
  78         close(ofd);
  79
  80         /*
  81          * Set up the ohash table to collect output line numbers
  82          * where various marked-up terms are documented.
  83          */
  84
  85         mandoc_ohash_init(&tag_data, 4, offsetof(struct tag_entry, s));
  86         return &tag_files;
  87
  88 fail:
  89         tag_unlink();
  90         if (ofd != -1)
  91                 close(ofd);
  92         if (tag_files.ofd != -1)
  93                 close(tag_files.ofd);
  94         if (tag_files.tfd != -1)
  95                 close(tag_files.tfd);
  96         *tag_files.ofn = '\0';
  97         *tag_files.tfn = '\0';
  98         tag_files.ofd = -1;
  99         tag_files.tfd = -1;
 100         return NULL;
 101 }
 102
 103 /*
 104  * Set the line number where a term is defined,
 105  * unless it is already defined at a higher priority.
 106  */
 107 void
 108 tag_put(const char *s, int prio, size_t line)
 109 {
 110         struct tag_entry        *entry;
 111         size_t                   len;
 112         unsigned int             slot;
 113
 114         if (tag_files.tfd <= 0 || strchr(s, ' ') != NULL)
 115                 return;
 116         slot = ohash_qlookup(&tag_data, s);
 117         entry = ohash_find(&tag_data, slot);
 118         if (entry == NULL) {
 119                 len = strlen(s) + 1;
 120                 entry = mandoc_malloc(sizeof(*entry) + len);
 121                 memcpy(entry->s, s, len);
 122                 ohash_insert(&tag_data, slot, entry);
 123         } else if (entry->prio <= prio)
 124                 return;
 125         entry->line = line;
 126         entry->prio = prio;
 127 }
 128
 129 /*
 130  * Write out the tags file using the previously collected
 131  * information and clear the ohash table while going along.
 132  */
 133 void
 134 tag_write(void)
 135 {
 136         FILE                    *stream;
 137         struct tag_entry        *entry;
 138         unsigned int             slot;
 139
 140         if (tag_files.tfd <= 0)
 141                 return;
 142         stream = fdopen(tag_files.tfd, "w");
 143         entry = ohash_first(&tag_data, &slot);
 144         while (entry != NULL) {
 145                 if (stream != NULL)
 146                         fprintf(stream, "%s %s %zu\n",
 147                             entry->s, tag_files.ofn, entry->line);
 148                 free(entry);
 149                 entry = ohash_next(&tag_data, &slot);
 150         }
 151         ohash_delete(&tag_data);
 152         if (stream != NULL)
 153                 fclose(stream);
 154 }
 155
 156 void
 157 tag_unlink(void)
 158 {
 159
 160         if (*tag_files.ofn != '\0')
 161                 unlink(tag_files.ofn);
 162         if (*tag_files.tfn != '\0')
 163                 unlink(tag_files.tfn);
 164 }
 165
 166 static void
 167 tag_signal(int signum)
 168 {
 169
 170         tag_unlink();
 171         signal(signum, SIG_DFL);
 172         kill(getpid(), signum);
 173         /* NOTREACHED */
 174         _exit(1);
 175 }