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//===-- Linux implementation of readlink ----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "src/unistd/readlink.h"
#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"
#include "hdr/fcntl_macros.h"
#include "src/__support/libc_errno.h"
#include "src/__support/macros/config.h"
#include <sys/syscall.h> // For syscall numbers.
namespace LIBC_NAMESPACE_DECL {
LLVM_LIBC_FUNCTION(ssize_t, readlink,
(const char *__restrict path, char *__restrict buf,
size_t bufsize)) {
#ifdef SYS_readlink
ssize_t ret =
LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_readlink, path, buf, bufsize);
#elif defined(SYS_readlinkat)
ssize_t ret = LIBC_NAMESPACE::syscall_impl<ssize_t>(SYS_readlinkat, AT_FDCWD,
path, buf, bufsize);
#else
#error "readlink or readlinkat syscalls not available."
#endif
if (ret < 0) {
libc_errno = static_cast<int>(-ret);
return -1;
}
return ret;
}
} // namespace LIBC_NAMESPACE_DECL
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