blob: cc275c507c9ed0893902427f93077abb5be5bc09 [file] [log] [blame]
/* Simple subrs.
Copyright (C) 2019 Free Software Foundation, Inc.
This file is part of libctf.
libctf is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; see the file COPYING. If not see
<http://www.gnu.org/licenses/>. */
#include <ctf-impl.h>
#ifdef HAVE_MMAP
#include <sys/mman.h>
#endif
#include <sys/types.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#ifndef ENOTSUP
#define ENOTSUP ENOSYS
#endif
int _libctf_version = CTF_VERSION; /* Library client version. */
int _libctf_debug = 0; /* Debugging messages enabled. */
/* Private, read-only mmap from a file, with fallback to copying.
No handling of page-offset issues at all: the caller must allow for that. */
_libctf_malloc_ void *
ctf_mmap (size_t length, size_t offset, int fd)
{
void *data;
#ifdef HAVE_MMAP
data = mmap (NULL, length, PROT_READ, MAP_PRIVATE, fd, offset);
if (data == MAP_FAILED)
data = NULL;
#else
if ((data = malloc (length)) != NULL)
{
if (ctf_pread (fd, data, length, offset) <= 0)
{
free (data);
data = NULL;
}
}
#endif
return data;
}
void
ctf_munmap (void *buf, size_t length _libctf_unused_)
{
#ifdef HAVE_MMAP
(void) munmap (buf, length);
#else
free (buf);
#endif
}
ssize_t
ctf_pread (int fd, void *buf, ssize_t count, off_t offset)
{
ssize_t len;
size_t acc = 0;
char *data = (char *) buf;
#ifdef HAVE_PREAD
while (count > 0)
{
errno = 0;
if (((len = pread (fd, data, count, offset)) < 0) &&
errno != EINTR)
return len;
if (errno == EINTR)
continue;
acc += len;
if (len == 0) /* EOF. */
return acc;
count -= len;
offset += len;
data += len;
}
return acc;
#else
off_t orig_off;
if ((orig_off = lseek (fd, 0, SEEK_CUR)) < 0)
return -1;
if ((lseek (fd, offset, SEEK_SET)) < 0)
return -1;
while (count > 0)
{
errno = 0;
if (((len = read (fd, data, count)) < 0) &&
errno != EINTR)
return len;
if (errno == EINTR)
continue;
acc += len;
if (len == 0) /* EOF. */
break;
count -= len;
data += len;
}
if ((lseek (fd, orig_off, SEEK_SET)) < 0)
return -1; /* offset is smashed. */
#endif
return acc;
}
const char *
ctf_strerror (int err)
{
return (const char *) (strerror (err));
}
/* Set the CTF library client version to the specified version. If version is
zero, we just return the default library version number. */
int
ctf_version (int version)
{
if (version < 0)
{
errno = EINVAL;
return -1;
}
if (version > 0)
{
/* Dynamic version switching is not presently supported. */
if (version != CTF_VERSION)
{
errno = ENOTSUP;
return -1;
}
ctf_dprintf ("ctf_version: client using version %d\n", version);
_libctf_version = version;
}
return _libctf_version;
}
void
libctf_init_debug (void)
{
static int inited;
if (!inited)
{
_libctf_debug = getenv ("LIBCTF_DEBUG") != NULL;
inited = 1;
}
}
void ctf_setdebug (int debug)
{
/* Ensure that libctf_init_debug() has been called, so that we don't get our
debugging-on-or-off smashed by the next call. */
libctf_init_debug();
_libctf_debug = debug;
ctf_dprintf ("CTF debugging set to %i\n", debug);
}
int ctf_getdebug (void)
{
return _libctf_debug;
}
_libctf_printflike_ (1, 2)
void ctf_dprintf (const char *format, ...)
{
if (_libctf_debug)
{
va_list alist;
va_start (alist, format);
fflush (stdout);
(void) fputs ("libctf DEBUG: ", stderr);
(void) vfprintf (stderr, format, alist);
va_end (alist);
}
}