src/unistd/linux/pread.cpp

//===-- Linux implementation of pread -------------------------------------===//
//
// 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/pread.h"

#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
#include "src/__support/common.h"

#include "src/errno/libc_errno.h"
#include <sys/syscall.h> // For syscall numbers.

namespace __llvm_libc {

LLVM_LIBC_FUNCTION(ssize_t, pread,
                   (int fd, void *buf, size_t count, off_t offset)) {
  long ret = __llvm_libc::syscall_impl(SYS_pread64, fd, buf, count, offset);
  if (ret < 0) {
    libc_errno = -ret;
    return -1;
  }
  return ret;
}

} // namespace __llvm_libc