1 /* $Id: tag.c,v 1.24 2019/07/22 03:21:50 schwarze Exp $ */ 2 /* 3 * Copyright (c) 2015, 2016, 2018, 2019 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 <errno.h> 22 #include <limits.h> 23 #include <signal.h> 24 #include <stddef.h> 25 #include <stdint.h> 26 #include <stdio.h> 27 #include <stdlib.h> 28 #include <string.h> 29 #include <unistd.h> 30 31 #include "mandoc_aux.h" 32 #include "mandoc_ohash.h" 33 #include "mandoc.h" 34 #include "tag.h" 35 36 struct tag_entry { 37 size_t *lines; 38 size_t maxlines; 39 size_t nlines; 40 int prio; 41 char s[]; 42 }; 43 44 static void tag_signal(int) __attribute__((__noreturn__)); 45 46 static struct ohash tag_data; 47 static struct tag_files tag_files; 48 49 50 /* 51 * Prepare for using a pager. 52 * Not all pagers are capable of using a tag file, 53 * but for simplicity, create it anyway. 54 */ 55 struct tag_files * 56 tag_init(void) 57 { 58 struct sigaction sa; 59 int ofd; 60 61 ofd = -1; 62 tag_files.tfd = -1; 63 tag_files.tcpgid = -1; 64 65 /* Clean up when dying from a signal. */ 66 67 memset(&sa, 0, sizeof(sa)); 68 sigfillset(&sa.sa_mask); 69 sa.sa_handler = tag_signal; 70 sigaction(SIGHUP, &sa, NULL); 71 sigaction(SIGINT, &sa, NULL); 72 sigaction(SIGTERM, &sa, NULL); 73 74 /* 75 * POSIX requires that a process calling tcsetpgrp(3) 76 * from the background gets a SIGTTOU signal. 77 * In that case, do not stop. 78 */ 79 80 sa.sa_handler = SIG_IGN; 81 sigaction(SIGTTOU, &sa, NULL); 82 83 /* Save the original standard output for use by the pager. */ 84 85 if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1) { 86 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno)); 87 goto fail; 88 } 89 90 /* Create both temporary output files. */ 91 92 (void)strlcpy(tag_files.ofn, "/tmp/man.XXXXXXXXXX", 93 sizeof(tag_files.ofn)); 94 (void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX", 95 sizeof(tag_files.tfn)); 96 if ((ofd = mkstemp(tag_files.ofn)) == -1) { 97 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0, 98 "%s: %s", tag_files.ofn, strerror(errno)); 99 goto fail; 100 } 101 if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1) { 102 mandoc_msg(MANDOCERR_MKSTEMP, 0, 0, 103 "%s: %s", tag_files.tfn, strerror(errno)); 104 goto fail; 105 } 106 if (dup2(ofd, STDOUT_FILENO) == -1) { 107 mandoc_msg(MANDOCERR_DUP, 0, 0, "%s", strerror(errno)); 108 goto fail; 109 } 110 close(ofd); 111 112 /* 113 * Set up the ohash table to collect output line numbers 114 * where various marked-up terms are documented. 115 */ 116 117 mandoc_ohash_init(&tag_data, 4, offsetof(struct tag_entry, s)); 118 return &tag_files; 119 120 fail: 121 tag_unlink(); 122 if (ofd != -1) 123 close(ofd); 124 if (tag_files.ofd != -1) 125 close(tag_files.ofd); 126 if (tag_files.tfd != -1) 127 close(tag_files.tfd); 128 *tag_files.ofn = '\0'; 129 *tag_files.tfn = '\0'; 130 tag_files.ofd = -1; 131 tag_files.tfd = -1; 132 return NULL; 133 } 134 135 /* 136 * Set the line number where a term is defined, 137 * unless it is already defined at a lower priority. 138 */ 139 void 140 tag_put(const char *s, int prio, size_t line) 141 { 142 struct tag_entry *entry; 143 const char *se; 144 size_t len; 145 unsigned int slot; 146 147 if (tag_files.tfd <= 0) 148 return; 149 150 if (s[0] == '\\' && (s[1] == '&' || s[1] == 'e')) 151 s += 2; 152 153 /* 154 * Skip whitespace and escapes and whatever follows, 155 * and if there is any, downgrade the priority. 156 */ 157 158 len = strcspn(s, " \t\\"); 159 if (len == 0) 160 return; 161 162 se = s + len; 163 if (*se != '\0') 164 prio = INT_MAX; 165 166 slot = ohash_qlookupi(&tag_data, s, &se); 167 entry = ohash_find(&tag_data, slot); 168 169 if (entry == NULL) { 170 171 /* Build a new entry. */ 172 173 entry = mandoc_malloc(sizeof(*entry) + len + 1); 174 memcpy(entry->s, s, len); 175 entry->s[len] = '\0'; 176 entry->lines = NULL; 177 entry->maxlines = entry->nlines = 0; 178 ohash_insert(&tag_data, slot, entry); 179 180 } else { 181 182 /* 183 * Lower priority numbers take precedence, 184 * but 0 is special. 185 * A tag with priority 0 is only used 186 * if the tag occurs exactly once. 187 */ 188 189 if (prio == 0) { 190 if (entry->prio == 0) 191 entry->prio = -1; 192 return; 193 } 194 195 /* A better entry is already present, ignore the new one. */ 196 197 if (entry->prio > 0 && entry->prio < prio) 198 return; 199 200 /* The existing entry is worse, clear it. */ 201 202 if (entry->prio < 1 || entry->prio > prio) 203 entry->nlines = 0; 204 } 205 206 /* Remember the new line. */ 207 208 if (entry->maxlines == entry->nlines) { 209 entry->maxlines += 4; 210 entry->lines = mandoc_reallocarray(entry->lines, 211 entry->maxlines, sizeof(*entry->lines)); 212 } 213 entry->lines[entry->nlines++] = line; 214 entry->prio = prio; 215 } 216 217 /* 218 * Write out the tags file using the previously collected 219 * information and clear the ohash table while going along. 220 */ 221 void 222 tag_write(void) 223 { 224 FILE *stream; 225 struct tag_entry *entry; 226 size_t i; 227 unsigned int slot; 228 int empty; 229 230 if (tag_files.tfd <= 0) 231 return; 232 if (tag_files.tagname != NULL && ohash_find(&tag_data, 233 ohash_qlookup(&tag_data, tag_files.tagname)) == NULL) { 234 mandoc_msg(MANDOCERR_TAG, 0, 0, "%s", tag_files.tagname); 235 tag_files.tagname = NULL; 236 } 237 if ((stream = fdopen(tag_files.tfd, "w")) == NULL) 238 mandoc_msg(MANDOCERR_FDOPEN, 0, 0, "%s", strerror(errno)); 239 empty = 1; 240 entry = ohash_first(&tag_data, &slot); 241 while (entry != NULL) { 242 if (stream != NULL && entry->prio >= 0) { 243 for (i = 0; i < entry->nlines; i++) { 244 fprintf(stream, "%s %s %zu\n", 245 entry->s, tag_files.ofn, entry->lines[i]); 246 empty = 0; 247 } 248 } 249 free(entry->lines); 250 free(entry); 251 entry = ohash_next(&tag_data, &slot); 252 } 253 ohash_delete(&tag_data); 254 if (stream != NULL) 255 fclose(stream); 256 else 257 close(tag_files.tfd); 258 tag_files.tfd = -1; 259 if (empty) { 260 unlink(tag_files.tfn); 261 *tag_files.tfn = '\0'; 262 } 263 } 264 265 void 266 tag_unlink(void) 267 { 268 pid_t tc_pgid; 269 270 if (tag_files.tcpgid != -1) { 271 tc_pgid = tcgetpgrp(tag_files.ofd); 272 if (tc_pgid == tag_files.pager_pid || 273 tc_pgid == getpgid(0) || 274 getpgid(tc_pgid) == -1) 275 (void)tcsetpgrp(tag_files.ofd, tag_files.tcpgid); 276 } 277 if (*tag_files.ofn != '\0') 278 unlink(tag_files.ofn); 279 if (*tag_files.tfn != '\0') 280 unlink(tag_files.tfn); 281 } 282 283 static void 284 tag_signal(int signum) 285 { 286 struct sigaction sa; 287 288 tag_unlink(); 289 memset(&sa, 0, sizeof(sa)); 290 sigemptyset(&sa.sa_mask); 291 sa.sa_handler = SIG_DFL; 292 sigaction(signum, &sa, NULL); 293 kill(getpid(), signum); 294 /* NOTREACHED */ 295 _exit(1); 296 } 297