#ifdef __linux__
/* posix.c -- POSIX file I/O routines for the backtrace library.
   Copyright (C) 2012-2024 Free Software Foundation, Inc.
   Written by Ian Lance Taylor, Google.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

	(1) Redistributions of source code must retain the above copyright
	notice, this list of conditions and the following disclaimer.

	(2) Redistributions in binary form must reproduce the above copyright
	notice, this list of conditions and the following disclaimer in
	the documentation and/or other materials provided with the
	distribution.

	(3) The name of the author may not be used to
	endorse or promote products derived from this software without
	specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.  */

#include "config.h"

#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "backtrace.h"
#include "internal.h"

#ifndef O_BINARY
#define O_BINARY 0
#endif

#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#endif

#ifndef FD_CLOEXEC
#define FD_CLOEXEC 1
#endif

/* Open a file for reading.  */

int backtrace_open(const char *filename, backtrace_error_callback error_callback, void *data, int *does_not_exist) {
	int descriptor;

	if (does_not_exist != NULL) *does_not_exist = 0;

	descriptor = open(filename, (int)(O_RDONLY | O_BINARY | O_CLOEXEC));
	if (descriptor < 0) {
		/* If DOES_NOT_EXIST is not NULL, then don't call ERROR_CALLBACK
	   if the file does not exist.  We treat lacking permission to
	   open the file as the file not existing; this case arises when
	   running the libgo syscall package tests as root.  */
		if (does_not_exist != NULL && (errno == ENOENT || errno == EACCES))
			*does_not_exist = 1;
		else
			error_callback(data, filename, errno);
		return -1;
	}

#ifdef HAVE_FCNTL
	/* Set FD_CLOEXEC just in case the kernel does not support
	   O_CLOEXEC. It doesn't matter if this fails for some reason.
	   FIXME: At some point it should be safe to only do this if
	   O_CLOEXEC == 0.  */
	fcntl(descriptor, F_SETFD, FD_CLOEXEC);
#endif

	return descriptor;
}

/* Close DESCRIPTOR.  */

int backtrace_close(int descriptor, backtrace_error_callback error_callback, void *data) {
	if (close(descriptor) < 0) {
		error_callback(data, "close", errno);
		return 0;
	}
	return 1;
}
#else
int ___posix_c_dummy_suppress_warning;
#endif
