Remove __wasilibc_unmodified_upstream markers from libc-bottom-half.

[wasi-libc.git] / libc-bottom-half / cloudlibc / src / libc / unistd / lseek.c

// Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
//
// SPDX-License-Identifier: BSD-2-Clause

#include <assert.h>
#include <wasi/api.h>
#include <errno.h>
#include <unistd.h>

static_assert(SEEK_CUR == __WASI_WHENCE_CUR, "Value mismatch");
static_assert(SEEK_END == __WASI_WHENCE_END, "Value mismatch");
static_assert(SEEK_SET == __WASI_WHENCE_SET, "Value mismatch");

off_t __lseek(int fildes, off_t offset, int whence) {
  __wasi_filesize_t new_offset;
  __wasi_errno_t error =
      __wasi_fd_seek(fildes, offset, whence, &new_offset);
  if (error != 0) {
    errno = error == ENOTCAPABLE ? ESPIPE : error;
    return -1;
  }
  return new_offset;
}

extern __typeof(__lseek) lseek __attribute__((weak, alias("__lseek")));