freebsd-dev/contrib/mdocml/tag.c
2017-02-19 17:46:37 +00:00

250 lines
5.5 KiB
C

/* $Id: tag.c,v 1.18 2017/02/17 14:31:52 schwarze Exp $ */
/*
* Copyright (c) 2015, 2016 Ingo Schwarze <schwarze@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "config.h"
#include <sys/types.h>
#include <signal.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "mandoc_aux.h"
#include "mandoc_ohash.h"
#include "tag.h"
struct tag_entry {
size_t *lines;
size_t maxlines;
size_t nlines;
int prio;
char s[];
};
static void tag_signal(int) __attribute__((__noreturn__));
static struct ohash tag_data;
static struct tag_files tag_files;
/*
* Prepare for using a pager.
* Not all pagers are capable of using a tag file,
* but for simplicity, create it anyway.
*/
struct tag_files *
tag_init(void)
{
struct sigaction sa;
int ofd;
ofd = -1;
tag_files.tfd = -1;
tag_files.tcpgid = -1;
/* Clean up when dying from a signal. */
memset(&sa, 0, sizeof(sa));
sigfillset(&sa.sa_mask);
sa.sa_handler = tag_signal;
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
/*
* POSIX requires that a process calling tcsetpgrp(3)
* from the background gets a SIGTTOU signal.
* In that case, do not stop.
*/
sa.sa_handler = SIG_IGN;
sigaction(SIGTTOU, &sa, NULL);
/* Save the original standard output for use by the pager. */
if ((tag_files.ofd = dup(STDOUT_FILENO)) == -1)
goto fail;
/* Create both temporary output files. */
(void)strlcpy(tag_files.ofn, "/tmp/man.XXXXXXXXXX",
sizeof(tag_files.ofn));
(void)strlcpy(tag_files.tfn, "/tmp/man.XXXXXXXXXX",
sizeof(tag_files.tfn));
if ((ofd = mkstemp(tag_files.ofn)) == -1)
goto fail;
if ((tag_files.tfd = mkstemp(tag_files.tfn)) == -1)
goto fail;
if (dup2(ofd, STDOUT_FILENO) == -1)
goto fail;
close(ofd);
/*
* Set up the ohash table to collect output line numbers
* where various marked-up terms are documented.
*/
mandoc_ohash_init(&tag_data, 4, offsetof(struct tag_entry, s));
return &tag_files;
fail:
tag_unlink();
if (ofd != -1)
close(ofd);
if (tag_files.ofd != -1)
close(tag_files.ofd);
if (tag_files.tfd != -1)
close(tag_files.tfd);
*tag_files.ofn = '\0';
*tag_files.tfn = '\0';
tag_files.ofd = -1;
tag_files.tfd = -1;
return NULL;
}
/*
* Set the line number where a term is defined,
* unless it is already defined at a higher priority.
*/
void
tag_put(const char *s, int prio, size_t line)
{
struct tag_entry *entry;
size_t len;
unsigned int slot;
/* Sanity checks. */
if (tag_files.tfd <= 0)
return;
if (s[0] == '\\' && (s[1] == '&' || s[1] == 'e'))
s += 2;
if (*s == '\0' || strchr(s, ' ') != NULL)
return;
slot = ohash_qlookup(&tag_data, s);
entry = ohash_find(&tag_data, slot);
if (entry == NULL) {
/* Build a new entry. */
len = strlen(s) + 1;
entry = mandoc_malloc(sizeof(*entry) + len);
memcpy(entry->s, s, len);
entry->lines = NULL;
entry->maxlines = entry->nlines = 0;
ohash_insert(&tag_data, slot, entry);
} else {
/* Handle priority 0 entries. */
if (prio == 0) {
if (entry->prio == 0)
entry->prio = -1;
return;
}
/* A better entry is already present, ignore the new one. */
if (entry->prio > 0 && entry->prio < prio)
return;
/* The existing entry is worse, clear it. */
if (entry->prio < 1 || entry->prio > prio)
entry->nlines = 0;
}
/* Remember the new line. */
if (entry->maxlines == entry->nlines) {
entry->maxlines += 4;
entry->lines = mandoc_reallocarray(entry->lines,
entry->maxlines, sizeof(*entry->lines));
}
entry->lines[entry->nlines++] = line;
entry->prio = prio;
}
/*
* Write out the tags file using the previously collected
* information and clear the ohash table while going along.
*/
void
tag_write(void)
{
FILE *stream;
struct tag_entry *entry;
size_t i;
unsigned int slot;
if (tag_files.tfd <= 0)
return;
stream = fdopen(tag_files.tfd, "w");
entry = ohash_first(&tag_data, &slot);
while (entry != NULL) {
if (stream != NULL && entry->prio >= 0)
for (i = 0; i < entry->nlines; i++)
fprintf(stream, "%s %s %zu\n",
entry->s, tag_files.ofn, entry->lines[i]);
free(entry->lines);
free(entry);
entry = ohash_next(&tag_data, &slot);
}
ohash_delete(&tag_data);
if (stream != NULL)
fclose(stream);
}
void
tag_unlink(void)
{
pid_t tc_pgid;
if (tag_files.tcpgid != -1) {
tc_pgid = tcgetpgrp(tag_files.ofd);
if (tc_pgid == tag_files.pager_pid ||
tc_pgid == getpgid(0) ||
getpgid(tc_pgid) == -1)
(void)tcsetpgrp(tag_files.ofd, tag_files.tcpgid);
}
if (*tag_files.ofn != '\0')
unlink(tag_files.ofn);
if (*tag_files.tfn != '\0')
unlink(tag_files.tfn);
}
static void
tag_signal(int signum)
{
struct sigaction sa;
tag_unlink();
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_handler = SIG_DFL;
sigaction(signum, &sa, NULL);
kill(getpid(), signum);
/* NOTREACHED */
_exit(1);
}