1//===-- Implementation of open --------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/fcntl/open.h"
10
11#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
12#include "src/__support/common.h"
13#include "src/__support/libc_errno.h"
14#include "src/__support/macros/config.h"
15
16#include "hdr/fcntl_macros.h"
17#include "hdr/types/mode_t.h"
18#include <stdarg.h>
19#include <sys/syscall.h> // For syscall numbers.
20
21namespace LIBC_NAMESPACE_DECL {
22
23LLVM_LIBC_FUNCTION(int, open, (const char *path, int flags, ...)) {
24 mode_t mode_flags = 0;
25 // O_TMPFILE is a multi-bit flag so we test all bits by checking for equality
26 // with O_TMPFILE
27 if ((flags & O_CREAT) || (flags & O_TMPFILE) == O_TMPFILE) {
28 va_list varargs;
29 va_start(varargs, flags);
30 mode_flags = va_arg(varargs, mode_t);
31 va_end(varargs);
32 }
33
34#ifdef SYS_open
35 int fd = LIBC_NAMESPACE::syscall_impl<int>(SYS_open, path, flags, mode_flags);
36#else
37 int fd = LIBC_NAMESPACE::syscall_impl<int>(SYS_openat, AT_FDCWD, path, flags,
38 mode_flags);
39#endif
40 if (fd > 0)
41 return fd;
42
43 libc_errno = -fd;
44 return -1;
45}
46
47} // namespace LIBC_NAMESPACE_DECL
48

source code of libc/src/fcntl/linux/open.cpp