From 6896ed383dbd3a847ef39b713449fc0393292828 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 09:47:58 +0300
Subject: [PATCH 01/21] use wasi crate

---
 src/libstd/sys/wasi/args.rs   |  16 +-
 src/libstd/sys/wasi/ext/fs.rs |   8 +-
 src/libstd/sys/wasi/ext/io.rs |   8 +-
 src/libstd/sys/wasi/fd.rs     | 302 +++++++++++-----------------------
 src/libstd/sys/wasi/fs.rs     | 176 +++++++++-----------
 src/libstd/sys/wasi/io.rs     |  11 +-
 src/libstd/sys/wasi/mod.rs    |  31 ++--
 src/libstd/sys/wasi/os.rs     |  29 +---
 src/libstd/sys/wasi/stdio.rs  |  11 +-
 src/libstd/sys/wasi/thread.rs |   4 +-
 src/libstd/sys/wasi/time.rs   |  29 ++--
 11 files changed, 249 insertions(+), 376 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index 8b4b354d9fc20..679bb1b2cbe30 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -27,14 +27,24 @@ pub fn args() -> Args {
     })
 }
 
+fn cvt_wasi(r: u16) -> crate::io::Result<()> {
+    if r != 0 {
+        Err(Error::from_raw_os_error(r as i32))
+    } else {
+        Ok(())
+    }
+}
+
 fn maybe_args() -> io::Result<Args> {
+    // FIXME: replace with safe functions
+    use wasi::wasi_unstable::raw::{__wasi_args_sizes_get, __wasi_args_get};
     unsafe {
         let (mut argc, mut argv_buf_size) = (0, 0);
-        cvt_wasi(libc::__wasi_args_sizes_get(&mut argc, &mut argv_buf_size))?;
+        cvt_wasi(__wasi_args_sizes_get(&mut argc, &mut argv_buf_size))?;
 
-        let mut argc = vec![core::ptr::null_mut::<libc::c_char>(); argc];
+        let mut argc = vec![core::ptr::null_mut::<u8>(); argc];
         let mut argv_buf = vec![0; argv_buf_size];
-        cvt_wasi(libc::__wasi_args_get(argc.as_mut_ptr(), argv_buf.as_mut_ptr()))?;
+        cvt_wasi(__wasi_args_get(argc.as_mut_ptr(), argv_buf.as_mut_ptr()))?;
 
         let args = argc.into_iter()
             .map(|ptr| CStr::from_ptr(ptr).to_bytes().to_vec())
diff --git a/src/libstd/sys/wasi/ext/fs.rs b/src/libstd/sys/wasi/ext/fs.rs
index 0ec4122f385da..ecd509f01dabd 100644
--- a/src/libstd/sys/wasi/ext/fs.rs
+++ b/src/libstd/sys/wasi/ext/fs.rs
@@ -336,16 +336,16 @@ pub trait FileTypeExt {
 
 impl FileTypeExt for fs::FileType {
     fn is_block_device(&self) -> bool {
-        self.as_inner().bits() == libc::__WASI_FILETYPE_BLOCK_DEVICE
+        self.as_inner().bits() == wasi::FILETYPE_BLOCK_DEVICE
     }
     fn is_character_device(&self) -> bool {
-        self.as_inner().bits() == libc::__WASI_FILETYPE_CHARACTER_DEVICE
+        self.as_inner().bits() == wasi::FILETYPE_CHARACTER_DEVICE
     }
     fn is_socket_dgram(&self) -> bool {
-        self.as_inner().bits() == libc::__WASI_FILETYPE_SOCKET_DGRAM
+        self.as_inner().bits() == wasi::FILETYPE_SOCKET_DGRAM
     }
     fn is_socket_stream(&self) -> bool {
-        self.as_inner().bits() == libc::__WASI_FILETYPE_SOCKET_STREAM
+        self.as_inner().bits() == wasi::FILETYPE_SOCKET_STREAM
     }
 }
 
diff --git a/src/libstd/sys/wasi/ext/io.rs b/src/libstd/sys/wasi/ext/io.rs
index 12afd1d42dc19..c843144f0c406 100644
--- a/src/libstd/sys/wasi/ext/io.rs
+++ b/src/libstd/sys/wasi/ext/io.rs
@@ -8,6 +8,8 @@ use crate::sys;
 use crate::net;
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 
+use wasi::wasi_unstable as wasi;
+
 /// Raw file descriptors.
 pub type RawFd = u32;
 
@@ -125,18 +127,18 @@ impl IntoRawFd for fs::File {
 
 impl AsRawFd for io::Stdin {
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDIN_FILENO as u32
+        wasi::STDIN_FD
     }
 }
 
 impl AsRawFd for io::Stdout {
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDOUT_FILENO as u32
+        wasi::STDOUT_FD
     }
 }
 
 impl AsRawFd for io::Stderr {
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDERR_FILENO as u32
+        wasi::STDERR_FD
     }
 }
diff --git a/src/libstd/sys/wasi/fd.rs b/src/libstd/sys/wasi/fd.rs
index 25692ec086801..93fe8add326c8 100644
--- a/src/libstd/sys/wasi/fd.rs
+++ b/src/libstd/sys/wasi/fd.rs
@@ -3,348 +3,240 @@
 use crate::io::{self, IoSlice, IoSliceMut, SeekFrom};
 use crate::mem;
 use crate::net::Shutdown;
-use crate::sys::cvt_wasi;
-use libc::{self, c_char, c_void};
+use wasi::wasi_unstable as wasi;
 
 #[derive(Debug)]
 pub struct WasiFd {
-    fd: libc::__wasi_fd_t,
+    fd: wasi::Fd,
 }
 
-// FIXME: these should probably all be fancier structs, builders, enums, etc
-pub type LookupFlags = u32;
-pub type FdFlags = u16;
-pub type Advice = u8;
-pub type Rights = u64;
-pub type Oflags = u16;
-pub type DirCookie = u64;
-pub type Timestamp = u64;
-pub type FstFlags = u16;
-pub type RiFlags = u16;
-pub type RoFlags = u16;
-pub type SiFlags = u16;
-
-fn iovec(a: &mut [IoSliceMut<'_>]) -> (*const libc::__wasi_iovec_t, usize) {
+fn iovec(a: &mut [IoSliceMut<'_>]) -> &[wasi::IoVec] {
     assert_eq!(
         mem::size_of::<IoSliceMut<'_>>(),
-        mem::size_of::<libc::__wasi_iovec_t>()
+        mem::size_of::<wasi::IoVec>()
     );
     assert_eq!(
         mem::align_of::<IoSliceMut<'_>>(),
-        mem::align_of::<libc::__wasi_iovec_t>()
+        mem::align_of::<wasi::IoVec>()
     );
-    (a.as_ptr() as *const libc::__wasi_iovec_t, a.len())
+    /// SAFETY: `IoSliceMut` and `IoVec` have exactly the same memory layout
+    unsafe { mem::transmute(a) }
 }
 
-fn ciovec(a: &[IoSlice<'_>]) -> (*const libc::__wasi_ciovec_t, usize) {
+fn ciovec(a: &[IoSlice<'_>]) -> &[wasi::CIoVec] {
     assert_eq!(
         mem::size_of::<IoSlice<'_>>(),
-        mem::size_of::<libc::__wasi_ciovec_t>()
+        mem::size_of::<wasi::CIoVec>()
     );
     assert_eq!(
         mem::align_of::<IoSlice<'_>>(),
-        mem::align_of::<libc::__wasi_ciovec_t>()
+        mem::align_of::<wasi::CIoVec>()
     );
-    (a.as_ptr() as *const libc::__wasi_ciovec_t, a.len())
+    /// SAFETY: `IoSlice` and `CIoVec` have exactly the same memory layout
+    unsafe { mem::transmute(a) }
 }
 
 impl WasiFd {
-    pub unsafe fn from_raw(fd: libc::__wasi_fd_t) -> WasiFd {
+    pub unsafe fn from_raw(fd: wasi::Fd) -> WasiFd {
         WasiFd { fd }
     }
 
-    pub fn into_raw(self) -> libc::__wasi_fd_t {
+    pub fn into_raw(self) -> wasi::Fd {
         let ret = self.fd;
         mem::forget(self);
         ret
     }
 
-    pub fn as_raw(&self) -> libc::__wasi_fd_t {
+    pub fn as_raw(&self) -> wasi::Fd {
         self.fd
     }
 
     pub fn datasync(&self) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_datasync(self.fd) })
+        wasi::fd_datasync(self.fd).map_err(From::from)
     }
 
     pub fn pread(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
-        let mut read = 0;
-        let (ptr, len) = iovec(bufs);
-        cvt_wasi(unsafe { libc::__wasi_fd_pread(self.fd, ptr, len, offset, &mut read) })?;
-        Ok(read)
+        wasi::fd_pread(self.fd, iovec(bufs), offset).map_err(From::from)
     }
 
     pub fn pwrite(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
-        let mut read = 0;
-        let (ptr, len) = ciovec(bufs);
-        cvt_wasi(unsafe { libc::__wasi_fd_pwrite(self.fd, ptr, len, offset, &mut read) })?;
-        Ok(read)
+        wasi::fd_pwrite(self.fd, ciovec(bufs), offset).map_err(From::from)
     }
 
     pub fn read(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        let mut read = 0;
-        let (ptr, len) = iovec(bufs);
-        cvt_wasi(unsafe { libc::__wasi_fd_read(self.fd, ptr, len, &mut read) })?;
-        Ok(read)
+        wasi::fd_read(self.fd, iovec(bufs)).map_err(From::from)
     }
 
     pub fn write(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        let mut read = 0;
-        let (ptr, len) = ciovec(bufs);
-        cvt_wasi(unsafe { libc::__wasi_fd_write(self.fd, ptr, len, &mut read) })?;
-        Ok(read)
+        wasi::fd_write(self.fd, ciovec(bufs)).map_err(From::from)
     }
 
     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
         let (whence, offset) = match pos {
-            SeekFrom::Start(pos) => (libc::__WASI_WHENCE_SET, pos as i64),
-            SeekFrom::End(pos) => (libc::__WASI_WHENCE_END, pos),
-            SeekFrom::Current(pos) => (libc::__WASI_WHENCE_CUR, pos),
+            SeekFrom::Start(pos) => (wasi::WHENCE_SET, pos as i64),
+            SeekFrom::End(pos) => (wasi::WHENCE_END, pos),
+            SeekFrom::Current(pos) => (wasi::WHENCE_CUR, pos),
         };
-        let mut pos = 0;
-        cvt_wasi(unsafe { libc::__wasi_fd_seek(self.fd, offset, whence, &mut pos) })?;
-        Ok(pos)
+        wasi::fd_seek(self.fd, offset, whence).map_err(From::from)
     }
 
     pub fn tell(&self) -> io::Result<u64> {
-        let mut pos = 0;
-        cvt_wasi(unsafe { libc::__wasi_fd_tell(self.fd, &mut pos) })?;
-        Ok(pos)
+        wasi::fd_tell(self.fd).map_err(From::from)
     }
 
     // FIXME: __wasi_fd_fdstat_get
 
-    pub fn set_flags(&self, flags: FdFlags) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_fdstat_set_flags(self.fd, flags) })
+    pub fn set_flags(&self, flags: wasi::FdFlags) -> io::Result<()> {
+        wasi::fd_fdstat_set_flags(self.fd, flags).map_err(From::from)
     }
 
-    pub fn set_rights(&self, base: Rights, inheriting: Rights) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_fdstat_set_rights(self.fd, base, inheriting) })
+    pub fn set_rights(&self, base: wasi::Rights, inheriting: wasi::Rights) -> io::Result<()> {
+        wasi::fd_fdstat_set_rights(self.fd, base, inheriting).map_err(From::from)
     }
 
     pub fn sync(&self) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_sync(self.fd) })
+        wasi::fd_sync(self.fd).map_err(From::from)
     }
 
-    pub fn advise(&self, offset: u64, len: u64, advice: Advice) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_advise(self.fd, offset, len, advice as u8) })
+    pub fn advise(&self, offset: u64, len: u64, advice: wasi::Advice) -> io::Result<()> {
+        wasi::fd_advise(self.fd, offset, len, advice).map_err(From::from)
     }
 
     pub fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_allocate(self.fd, offset, len) })
+        wasi::fd_allocate(self.fd, offset, len).map_err(From::from)
     }
 
     pub fn create_directory(&self, path: &[u8]) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_create_directory(self.fd, path.as_ptr() as *const c_char, path.len())
-        })
+        wasi::path_create_directory(self.fd, path).map_err(From::from)
     }
 
     pub fn link(
         &self,
-        old_flags: LookupFlags,
+        old_flags: wasi::LookupFlags,
         old_path: &[u8],
         new_fd: &WasiFd,
         new_path: &[u8],
     ) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_link(
-                self.fd,
-                old_flags,
-                old_path.as_ptr() as *const c_char,
-                old_path.len(),
-                new_fd.fd,
-                new_path.as_ptr() as *const c_char,
-                new_path.len(),
-            )
-        })
+        wasi::path_link(self.fd, old_flags, old_path, new_fd.fd, new_path)
+            .map_err(From::from)
     }
 
     pub fn open(
         &self,
-        dirflags: LookupFlags,
+        dirflags: wasi::LookupFlags,
         path: &[u8],
-        oflags: Oflags,
-        fs_rights_base: Rights,
-        fs_rights_inheriting: Rights,
-        fs_flags: FdFlags,
+        oflags: wasi::OFlags,
+        fs_rights_base: wasi::Rights,
+        fs_rights_inheriting: wasi::Rights,
+        fs_flags: wasi::FdFlags,
     ) -> io::Result<WasiFd> {
-        unsafe {
-            let mut fd = 0;
-            cvt_wasi(libc::__wasi_path_open(
-                self.fd,
-                dirflags,
-                path.as_ptr() as *const c_char,
-                path.len(),
-                oflags,
-                fs_rights_base,
-                fs_rights_inheriting,
-                fs_flags,
-                &mut fd,
-            ))?;
-            Ok(WasiFd::from_raw(fd))
-        }
-    }
-
-    pub fn readdir(&self, buf: &mut [u8], cookie: DirCookie) -> io::Result<usize> {
-        let mut used = 0;
-        cvt_wasi(unsafe {
-            libc::__wasi_fd_readdir(
-                self.fd,
-                buf.as_mut_ptr() as *mut c_void,
-                buf.len(),
-                cookie,
-                &mut used,
-            )
-        })?;
-        Ok(used)
+        let fd = wasi_path_open(
+            self.fd,
+            dirflags,
+            path,
+            oflags,
+            fs_rights_base,
+            fs_rights_inheriting,
+            fs_flags,
+        )?;
+        Ok(WasiFd::from_raw(fd))
+    }
+
+    pub fn readdir(&self, buf: &mut [u8], cookie: wasi::DirCookie) -> io::Result<usize> {
+        wasi::fd_readdir(self.fd, buf, cookie).map_err(From::from)
     }
 
     pub fn readlink(&self, path: &[u8], buf: &mut [u8]) -> io::Result<usize> {
-        let mut used = 0;
-        cvt_wasi(unsafe {
-            libc::__wasi_path_readlink(
-                self.fd,
-                path.as_ptr() as *const c_char,
-                path.len(),
-                buf.as_mut_ptr() as *mut c_char,
-                buf.len(),
-                &mut used,
-            )
-        })?;
-        Ok(used)
+        wasi::path_readlink(self.fd, path, buf).map_err(From::from)
     }
 
     pub fn rename(&self, old_path: &[u8], new_fd: &WasiFd, new_path: &[u8]) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_rename(
-                self.fd,
-                old_path.as_ptr() as *const c_char,
-                old_path.len(),
-                new_fd.fd,
-                new_path.as_ptr() as *const c_char,
-                new_path.len(),
-            )
-        })
+        wasi::path_rename(self.fd, old_path, new_fd.fd, new_path)
+            .map_err(From::from)
     }
 
-    pub fn filestat_get(&self, buf: *mut libc::__wasi_filestat_t) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_filestat_get(self.fd, buf) })
+    pub fn filestat_get(&self) -> io::Result<wasi::Filestat> {
+        wasi::fd_filestat_get(self.fd, buf).map_err(From::from)
     }
 
     pub fn filestat_set_times(
         &self,
-        atim: Timestamp,
-        mtim: Timestamp,
-        fstflags: FstFlags,
+        atim: wasi::Timestamp,
+        mtim: wasi::Timestamp,
+        fstflags: wasi::FstFlags,
     ) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_filestat_set_times(self.fd, atim, mtim, fstflags) })
+        wasi::fd_filestat_set_times(self.fd, atim, mtim, fstflags)
+            .map_err(From::from)
     }
 
     pub fn filestat_set_size(&self, size: u64) -> io::Result<()> {
-        cvt_wasi(unsafe { libc::__wasi_fd_filestat_set_size(self.fd, size) })
+        wasi::fd_filestat_set_size(self.fd, size).map_err(From::from)
     }
 
     pub fn path_filestat_get(
         &self,
-        flags: LookupFlags,
+        flags: wasi::LookupFlags,
         path: &[u8],
-        buf: *mut libc::__wasi_filestat_t,
-    ) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_filestat_get(
-                self.fd,
-                flags,
-                path.as_ptr() as *const c_char,
-                path.len(),
-                buf,
-            )
-        })
+    ) -> io::Result<wasi::FileStat> {
+        wasi::path_filestat_get(self.fd, flags, path).map_err(From::from)
     }
 
     pub fn path_filestat_set_times(
         &self,
-        flags: LookupFlags,
+        flags: wasi::LookupFlags,
         path: &[u8],
-        atim: Timestamp,
-        mtim: Timestamp,
-        fstflags: FstFlags,
+        atim: wasi::Timestamp,
+        mtim: wasi::Timestamp,
+        fstflags: wasi::FstFlags,
     ) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_filestat_set_times(
-                self.fd,
-                flags,
-                path.as_ptr() as *const c_char,
-                path.len(),
-                atim,
-                mtim,
-                fstflags,
-            )
-        })
+        wasi::path_filestat_set_times(
+            self.fd,
+            flags,
+            path,
+            atim,
+            mtim,
+            fstflags,
+        ).map_err(From::from)
     }
 
     pub fn symlink(&self, old_path: &[u8], new_path: &[u8]) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_symlink(
-                old_path.as_ptr() as *const c_char,
-                old_path.len(),
-                self.fd,
-                new_path.as_ptr() as *const c_char,
-                new_path.len(),
-            )
-        })
+        wasi::path_symlink(old_path, self.fd, new_path).map_err(From::from)
     }
 
     pub fn unlink_file(&self, path: &[u8]) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_unlink_file(self.fd, path.as_ptr() as *const c_char, path.len())
-        })
+        wasi::path_unlink_file(self.fd, path).map_err(From::from)
     }
 
     pub fn remove_directory(&self, path: &[u8]) -> io::Result<()> {
-        cvt_wasi(unsafe {
-            libc::__wasi_path_remove_directory(self.fd, path.as_ptr() as *const c_char, path.len())
-        })
+        wasi::path_remove_directory(self.fd, path).map_err(From::from)
     }
 
     pub fn sock_recv(
         &self,
         ri_data: &mut [IoSliceMut<'_>],
-        ri_flags: RiFlags,
-    ) -> io::Result<(usize, RoFlags)> {
-        let mut ro_datalen = 0;
-        let mut ro_flags = 0;
-        let (ptr, len) = iovec(ri_data);
-        cvt_wasi(unsafe {
-            libc::__wasi_sock_recv(self.fd, ptr, len, ri_flags, &mut ro_datalen, &mut ro_flags)
-        })?;
-        Ok((ro_datalen, ro_flags))
+        ri_flags: wasi::RiFlags,
+    ) -> io::Result<(usize, wasi::RoFlags)> {
+        wasi::sock_recv(self.fd, iovec(ri_data), ri_flags).map_err(From::from)
     }
 
-    pub fn sock_send(&self, si_data: &[IoSlice<'_>], si_flags: SiFlags) -> io::Result<usize> {
-        let mut so_datalen = 0;
-        let (ptr, len) = ciovec(si_data);
-        cvt_wasi(unsafe { libc::__wasi_sock_send(self.fd, ptr, len, si_flags, &mut so_datalen) })?;
-        Ok(so_datalen)
+    pub fn sock_send(&self, si_data: &[IoSlice<'_>], si_flags: wasi::SiFlags) -> io::Result<usize> {
+        wasi::sock_send(self.fd, ciovec(si_data), si_flags).map_err(From::from)
     }
 
     pub fn sock_shutdown(&self, how: Shutdown) -> io::Result<()> {
         let how = match how {
-            Shutdown::Read => libc::__WASI_SHUT_RD,
-            Shutdown::Write => libc::__WASI_SHUT_WR,
-            Shutdown::Both => libc::__WASI_SHUT_WR | libc::__WASI_SHUT_RD,
+            Shutdown::Read => WASI::SHUT_RD,
+            Shutdown::Write => WASI::SHUT_WR,
+            Shutdown::Both => WASI::SHUT_WR | WASI::SHUT_RD,
         };
-        cvt_wasi(unsafe { libc::__wasi_sock_shutdown(self.fd, how) })?;
-        Ok(())
+        wasi::sock_shutdown(self.fd, how).map_err(From::from)
     }
 }
 
 impl Drop for WasiFd {
     fn drop(&mut self) {
-        unsafe {
-            // FIXME: can we handle the return code here even though we can't on
-            // unix?
-            libc::__wasi_fd_close(self.fd);
-        }
+        // FIXME: can we handle the return code here even though we can't on
+        // unix?
+        let _ = wasi::fd_close(self.fd);
     }
 }
diff --git a/src/libstd/sys/wasi/fs.rs b/src/libstd/sys/wasi/fs.rs
index 172c60385b317..f23ecfc2bcd22 100644
--- a/src/libstd/sys/wasi/fs.rs
+++ b/src/libstd/sys/wasi/fs.rs
@@ -15,13 +15,15 @@ use crate::sys_common::FromInner;
 pub use crate::sys_common::fs::copy;
 pub use crate::sys_common::fs::remove_dir_all;
 
+use wasi::wasi_unstable as wasi;
+
 pub struct File {
     fd: WasiFd,
 }
 
 #[derive(Clone)]
 pub struct FileAttr {
-    meta: libc::__wasi_filestat_t,
+    meta: wasi::FileStat,
 }
 
 pub struct ReadDir {
@@ -38,7 +40,7 @@ struct ReadDirInner {
 }
 
 pub struct DirEntry {
-    meta: libc::__wasi_dirent_t,
+    meta: wasi::Dirent,
     name: Vec<u8>,
     inner: Arc<ReadDirInner>,
 }
@@ -47,11 +49,11 @@ pub struct DirEntry {
 pub struct OpenOptions {
     read: bool,
     write: bool,
-    dirflags: libc::__wasi_lookupflags_t,
-    fdflags: libc::__wasi_fdflags_t,
-    oflags: libc::__wasi_oflags_t,
-    rights_base: Option<libc::__wasi_rights_t>,
-    rights_inheriting: Option<libc::__wasi_rights_t>,
+    dirflags: wasi::LookupFlags,
+    fdflags: wasi::FdFlags,
+    oflags: wasi::OFlags,
+    rights_base: Option<wasi::Rights>,
+    rights_inheriting: Option<wasi::Rights>,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -61,7 +63,7 @@ pub struct FilePermissions {
 
 #[derive(PartialEq, Eq, Hash, Debug, Copy, Clone)]
 pub struct FileType {
-    bits: libc::__wasi_filetype_t,
+    bits: wasi::FileType,
 }
 
 #[derive(Debug)]
@@ -101,7 +103,7 @@ impl FileAttr {
         Ok(SystemTime::from_wasi_timestamp(self.meta.st_ctim))
     }
 
-    pub fn as_wasi(&self) -> &libc::__wasi_filestat_t {
+    pub fn as_wasi(&self) -> &wasi::FileStat {
         &self.meta
     }
 }
@@ -118,18 +120,18 @@ impl FilePermissions {
 
 impl FileType {
     pub fn is_dir(&self) -> bool {
-        self.bits == libc::__WASI_FILETYPE_DIRECTORY
+        self.bits == wasi::FILETYPE_DIRECTORY
     }
 
     pub fn is_file(&self) -> bool {
-        self.bits == libc::__WASI_FILETYPE_REGULAR_FILE
+        self.bits == wasi::FILETYPE_REGULAR_FILE
     }
 
     pub fn is_symlink(&self) -> bool {
-        self.bits == libc::__WASI_FILETYPE_SYMBOLIC_LINK
+        self.bits == wasi::FILETYPE_SYMBOLIC_LINK
     }
 
-    pub fn bits(&self) -> libc::__wasi_filetype_t {
+    pub fn bits(&self) -> wasi::FileType {
         self.bits
     }
 }
@@ -173,7 +175,7 @@ impl Iterator for ReadDir {
             // must have been truncated at the end of the buffer, so reset our
             // offset so we can go back and reread into the buffer, picking up
             // where we last left off.
-            let dirent_size = mem::size_of::<libc::__wasi_dirent_t>();
+            let dirent_size = mem::size_of::<wasi::Dirent>();
             if data.len() < dirent_size {
                 assert!(self.cookie.is_some());
                 assert!(self.buf.len() >= dirent_size);
@@ -182,7 +184,7 @@ impl Iterator for ReadDir {
             }
             let (dirent, data) = data.split_at(dirent_size);
             let dirent =
-                unsafe { ptr::read_unaligned(dirent.as_ptr() as *const libc::__wasi_dirent_t) };
+                unsafe { ptr::read_unaligned(dirent.as_ptr() as *const wasi::Dirent) };
 
             // If the file name was truncated, then we need to reinvoke
             // `readdir` so we truncate our buffer to start over and reread this
@@ -241,7 +243,7 @@ impl DirEntry {
         })
     }
 
-    pub fn ino(&self) -> libc::__wasi_inode_t {
+    pub fn ino(&self) -> wasi::Inode {
         self.meta.d_ino
     }
 }
@@ -249,7 +251,7 @@ impl DirEntry {
 impl OpenOptions {
     pub fn new() -> OpenOptions {
         let mut base = OpenOptions::default();
-        base.dirflags = libc::__WASI_LOOKUP_SYMLINK_FOLLOW;
+        base.dirflags = wasi::LOOKUP_SYMLINK_FOLLOW;
         return base;
     }
 
@@ -262,23 +264,23 @@ impl OpenOptions {
     }
 
     pub fn truncate(&mut self, truncate: bool) {
-        self.oflag(libc::__WASI_O_TRUNC, truncate);
+        self.oflag(wasi::O_TRUNC, truncate);
     }
 
     pub fn create(&mut self, create: bool) {
-        self.oflag(libc::__WASI_O_CREAT, create);
+        self.oflag(wasi::O_CREAT, create);
     }
 
     pub fn create_new(&mut self, create_new: bool) {
-        self.oflag(libc::__WASI_O_EXCL, create_new);
-        self.oflag(libc::__WASI_O_CREAT, create_new);
+        self.oflag(wasi::O_EXCL, create_new);
+        self.oflag(wasi::O_CREAT, create_new);
     }
 
     pub fn directory(&mut self, directory: bool) {
-        self.oflag(libc::__WASI_O_DIRECTORY, directory);
+        self.oflag(wasi::O_DIRECTORY, directory);
     }
 
-    fn oflag(&mut self, bit: libc::__wasi_oflags_t, set: bool) {
+    fn oflag(&mut self, bit: wasi::OFlags, set: bool) {
         if set {
             self.oflags |= bit;
         } else {
@@ -287,26 +289,26 @@ impl OpenOptions {
     }
 
     pub fn append(&mut self, set: bool) {
-        self.fdflag(libc::__WASI_FDFLAG_APPEND, set);
+        self.fdflag(wasi::FDFLAG_APPEND, set);
     }
 
     pub fn dsync(&mut self, set: bool) {
-        self.fdflag(libc::__WASI_FDFLAG_DSYNC, set);
+        self.fdflag(wasi::FDFLAG_DSYNC, set);
     }
 
     pub fn nonblock(&mut self, set: bool) {
-        self.fdflag(libc::__WASI_FDFLAG_NONBLOCK, set);
+        self.fdflag(wasi::FDFLAG_NONBLOCK, set);
     }
 
     pub fn rsync(&mut self, set: bool) {
-        self.fdflag(libc::__WASI_FDFLAG_RSYNC, set);
+        self.fdflag(wasi::FDFLAG_RSYNC, set);
     }
 
     pub fn sync(&mut self, set: bool) {
-        self.fdflag(libc::__WASI_FDFLAG_SYNC, set);
+        self.fdflag(wasi::FDFLAG_SYNC, set);
     }
 
-    fn fdflag(&mut self, bit: libc::__wasi_fdflags_t, set: bool) {
+    fn fdflag(&mut self, bit: wasi::FdFlags, set: bool) {
         if set {
             self.fdflags |= bit;
         } else {
@@ -314,15 +316,15 @@ impl OpenOptions {
         }
     }
 
-    pub fn fs_rights_base(&mut self, rights: libc::__wasi_rights_t) {
+    pub fn fs_rights_base(&mut self, rights: wasi::Rights) {
         self.rights_base = Some(rights);
     }
 
-    pub fn fs_rights_inheriting(&mut self, rights: libc::__wasi_rights_t) {
+    pub fn fs_rights_inheriting(&mut self, rights: wasi::Rights) {
         self.rights_inheriting = Some(rights);
     }
 
-    fn rights_base(&self) -> libc::__wasi_rights_t {
+    fn rights_base(&self) -> wasi::Rights {
         if let Some(rights) = self.rights_base {
             return rights;
         }
@@ -334,52 +336,52 @@ impl OpenOptions {
         // based on that.
         let mut base = 0;
         if self.read {
-            base |= libc::__WASI_RIGHT_FD_READ;
-            base |= libc::__WASI_RIGHT_FD_READDIR;
+            base |= wasi::RIGHT_FD_READ;
+            base |= wasi::RIGHT_FD_READDIR;
         }
         if self.write {
-            base |= libc::__WASI_RIGHT_FD_WRITE;
-            base |= libc::__WASI_RIGHT_FD_DATASYNC;
-            base |= libc::__WASI_RIGHT_FD_ALLOCATE;
-            base |= libc::__WASI_RIGHT_FD_FILESTAT_SET_SIZE;
+            base |= wasi::RIGHT_FD_WRITE;
+            base |= wasi::RIGHT_FD_DATASYNC;
+            base |= wasi::RIGHT_FD_ALLOCATE;
+            base |= wasi::RIGHT_FD_FILESTAT_SET_SIZE;
         }
 
         // FIXME: some of these should probably be read-only or write-only...
-        base |= libc::__WASI_RIGHT_FD_ADVISE;
-        base |= libc::__WASI_RIGHT_FD_FDSTAT_SET_FLAGS;
-        base |= libc::__WASI_RIGHT_FD_FILESTAT_SET_TIMES;
-        base |= libc::__WASI_RIGHT_FD_SEEK;
-        base |= libc::__WASI_RIGHT_FD_SYNC;
-        base |= libc::__WASI_RIGHT_FD_TELL;
-        base |= libc::__WASI_RIGHT_PATH_CREATE_DIRECTORY;
-        base |= libc::__WASI_RIGHT_PATH_CREATE_FILE;
-        base |= libc::__WASI_RIGHT_PATH_FILESTAT_GET;
-        base |= libc::__WASI_RIGHT_PATH_LINK_SOURCE;
-        base |= libc::__WASI_RIGHT_PATH_LINK_TARGET;
-        base |= libc::__WASI_RIGHT_PATH_OPEN;
-        base |= libc::__WASI_RIGHT_PATH_READLINK;
-        base |= libc::__WASI_RIGHT_PATH_REMOVE_DIRECTORY;
-        base |= libc::__WASI_RIGHT_PATH_RENAME_SOURCE;
-        base |= libc::__WASI_RIGHT_PATH_RENAME_TARGET;
-        base |= libc::__WASI_RIGHT_PATH_SYMLINK;
-        base |= libc::__WASI_RIGHT_PATH_UNLINK_FILE;
-        base |= libc::__WASI_RIGHT_POLL_FD_READWRITE;
+        base |= wasi::RIGHT_FD_ADVISE;
+        base |= wasi::RIGHT_FD_FDSTAT_SET_FLAGS;
+        base |= wasi::RIGHT_FD_FILESTAT_SET_TIMES;
+        base |= wasi::RIGHT_FD_SEEK;
+        base |= wasi::RIGHT_FD_SYNC;
+        base |= wasi::RIGHT_FD_TELL;
+        base |= wasi::RIGHT_PATH_CREATE_DIRECTORY;
+        base |= wasi::RIGHT_PATH_CREATE_FILE;
+        base |= wasi::RIGHT_PATH_FILESTAT_GET;
+        base |= wasi::RIGHT_PATH_LINK_SOURCE;
+        base |= wasi::RIGHT_PATH_LINK_TARGET;
+        base |= wasi::RIGHT_PATH_OPEN;
+        base |= wasi::RIGHT_PATH_READLINK;
+        base |= wasi::RIGHT_PATH_REMOVE_DIRECTORY;
+        base |= wasi::RIGHT_PATH_RENAME_SOURCE;
+        base |= wasi::RIGHT_PATH_RENAME_TARGET;
+        base |= wasi::RIGHT_PATH_SYMLINK;
+        base |= wasi::RIGHT_PATH_UNLINK_FILE;
+        base |= wasi::RIGHT_POLL_FD_READWRITE;
 
         return base;
     }
 
-    fn rights_inheriting(&self) -> libc::__wasi_rights_t {
+    fn rights_inheriting(&self) -> wasi::Rights {
         self.rights_inheriting.unwrap_or_else(|| self.rights_base())
     }
 
-    pub fn lookup_flags(&mut self, flags: libc::__wasi_lookupflags_t) {
+    pub fn lookup_flags(&mut self, flags: wasi::LookupFlags) {
         self.dirflags = flags;
     }
 }
 
 impl File {
     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
-        let (dir, file) = open_parent(path, libc::__WASI_RIGHT_PATH_OPEN)?;
+        let (dir, file) = open_parent(path, wasi::RIGHT_PATH_OPEN)?;
         open_at(&dir, &file, opts)
     }
 
@@ -388,14 +390,12 @@ impl File {
     }
 
     pub fn file_attr(&self) -> io::Result<FileAttr> {
-        let mut ret = FileAttr::zero();
-        self.fd.filestat_get(&mut ret.meta)?;
-        Ok(ret)
+        self.fd.filestat_get().map_ok(|meta| FileAttr { meta })
     }
 
     pub fn metadata_at(
         &self,
-        flags: libc::__wasi_lookupflags_t,
+        flags: wasi::LookupFlags,
         path: &Path,
     ) -> io::Result<FileAttr> {
         metadata_at(&self.fd, flags, path)
@@ -477,7 +477,7 @@ impl DirBuilder {
     }
 
     pub fn mkdir(&self, p: &Path) -> io::Result<()> {
-        let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_CREATE_DIRECTORY)?;
+        let (dir, file) = open_parent(p, wasi::RIGHT_PATH_CREATE_DIRECTORY)?;
         dir.create_directory(file.as_os_str().as_bytes())
     }
 }
@@ -508,13 +508,13 @@ pub fn readdir(p: &Path) -> io::Result<ReadDir> {
 }
 
 pub fn unlink(p: &Path) -> io::Result<()> {
-    let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_UNLINK_FILE)?;
+    let (dir, file) = open_parent(p, wasi::RIGHT_PATH_UNLINK_FILE)?;
     dir.unlink_file(file.as_os_str().as_bytes())
 }
 
 pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
-    let (old, old_file) = open_parent(old, libc::__WASI_RIGHT_PATH_RENAME_SOURCE)?;
-    let (new, new_file) = open_parent(new, libc::__WASI_RIGHT_PATH_RENAME_TARGET)?;
+    let (old, old_file) = open_parent(old, wasi::RIGHT_PATH_RENAME_SOURCE)?;
+    let (new, new_file) = open_parent(new, wasi::RIGHT_PATH_RENAME_TARGET)?;
     old.rename(
         old_file.as_os_str().as_bytes(),
         &new,
@@ -529,12 +529,12 @@ pub fn set_perm(_p: &Path, _perm: FilePermissions) -> io::Result<()> {
 }
 
 pub fn rmdir(p: &Path) -> io::Result<()> {
-    let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_REMOVE_DIRECTORY)?;
+    let (dir, file) = open_parent(p, wasi::RIGHT_PATH_REMOVE_DIRECTORY)?;
     dir.remove_directory(file.as_os_str().as_bytes())
 }
 
 pub fn readlink(p: &Path) -> io::Result<PathBuf> {
-    let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_READLINK)?;
+    let (dir, file) = open_parent(p, wasi::RIGHT_PATH_READLINK)?;
     read_link(&dir, &file)
 }
 
@@ -570,15 +570,15 @@ fn read_link(fd: &WasiFd, file: &Path) -> io::Result<PathBuf> {
 }
 
 pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
-    let (dst, dst_file) = open_parent(dst, libc::__WASI_RIGHT_PATH_SYMLINK)?;
+    let (dst, dst_file) = open_parent(dst, wasi::RIGHT_PATH_SYMLINK)?;
     dst.symlink(src.as_os_str().as_bytes(), dst_file.as_os_str().as_bytes())
 }
 
 pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
-    let (src, src_file) = open_parent(src, libc::__WASI_RIGHT_PATH_LINK_SOURCE)?;
-    let (dst, dst_file) = open_parent(dst, libc::__WASI_RIGHT_PATH_LINK_TARGET)?;
+    let (src, src_file) = open_parent(src, wasi::RIGHT_PATH_LINK_SOURCE)?;
+    let (dst, dst_file) = open_parent(dst, wasi::RIGHT_PATH_LINK_TARGET)?;
     src.link(
-        libc::__WASI_LOOKUP_SYMLINK_FOLLOW,
+        wasi::LOOKUP_SYMLINK_FOLLOW,
         src_file.as_os_str().as_bytes(),
         &dst,
         dst_file.as_os_str().as_bytes(),
@@ -586,23 +586,22 @@ pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
 }
 
 pub fn stat(p: &Path) -> io::Result<FileAttr> {
-    let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_FILESTAT_GET)?;
-    metadata_at(&dir, libc::__WASI_LOOKUP_SYMLINK_FOLLOW, &file)
+    let (dir, file) = open_parent(p, wasi::RIGHT_PATH_FILESTAT_GET)?;
+    metadata_at(&dir, wasi::LOOKUP_SYMLINK_FOLLOW, &file)
 }
 
 pub fn lstat(p: &Path) -> io::Result<FileAttr> {
-    let (dir, file) = open_parent(p, libc::__WASI_RIGHT_PATH_FILESTAT_GET)?;
+    let (dir, file) = open_parent(p, wasi::RIGHT_PATH_FILESTAT_GET)?;
     metadata_at(&dir, 0, &file)
 }
 
 fn metadata_at(
     fd: &WasiFd,
-    flags: libc::__wasi_lookupflags_t,
+    flags: wasi::LookupFlags,
     path: &Path,
 ) -> io::Result<FileAttr> {
-    let mut ret = FileAttr::zero();
-    fd.path_filestat_get(flags, path.as_os_str().as_bytes(), &mut ret.meta)?;
-    Ok(ret)
+    fd.path_filestat_get(flags, path.as_os_str().as_bytes())
+        .map_ok(|meta| FileAttr { meta })
 }
 
 pub fn canonicalize(_p: &Path) -> io::Result<PathBuf> {
@@ -652,12 +651,12 @@ fn open_at(fd: &WasiFd, path: &Path, opts: &OpenOptions) -> io::Result<File> {
 /// to any preopened file descriptor.
 fn open_parent(
     p: &Path,
-    rights: libc::__wasi_rights_t,
+    rights: wasi::Rights,
 ) -> io::Result<(ManuallyDrop<WasiFd>, PathBuf)> {
     let p = CString::new(p.as_os_str().as_bytes())?;
     unsafe {
         let mut ret = ptr::null();
-        let fd = __wasilibc_find_relpath(p.as_ptr(), rights, 0, &mut ret);
+        let fd = libc::__wasilibc_find_relpath(p.as_ptr(), rights, 0, &mut ret);
         if fd == -1 {
             let msg = format!(
                 "failed to find a preopened file descriptor \
@@ -677,15 +676,4 @@ fn open_parent(
 
         return Ok((ManuallyDrop::new(WasiFd::from_raw(fd as u32)), path));
     }
-
-    // FIXME(rust-lang/libc#1314) use the `libc` crate for this when the API
-    // there is published
-    extern "C" {
-        pub fn __wasilibc_find_relpath(
-            path: *const libc::c_char,
-            rights_base: libc::__wasi_rights_t,
-            rights_inheriting: libc::__wasi_rights_t,
-            relative_path: *mut *const libc::c_char,
-        ) -> libc::c_int;
-    }
 }
diff --git a/src/libstd/sys/wasi/io.rs b/src/libstd/sys/wasi/io.rs
index ffecca5d1b6ff..ebea3a03e439f 100644
--- a/src/libstd/sys/wasi/io.rs
+++ b/src/libstd/sys/wasi/io.rs
@@ -1,11 +1,12 @@
 use crate::marker::PhantomData;
 use crate::slice;
 
-use libc::{__wasi_ciovec_t, __wasi_iovec_t, c_void};
+use wasi::wasi_unstable as wasi;
+use core::ffi::c_void;
 
 #[repr(transparent)]
 pub struct IoSlice<'a> {
-    vec: __wasi_ciovec_t,
+    vec: wasi::CIoVec,
     _p: PhantomData<&'a [u8]>,
 }
 
@@ -13,7 +14,7 @@ impl<'a> IoSlice<'a> {
     #[inline]
     pub fn new(buf: &'a [u8]) -> IoSlice<'a> {
         IoSlice {
-            vec: __wasi_ciovec_t {
+            vec: wasi::CIoVec {
                 buf: buf.as_ptr() as *const c_void,
                 buf_len: buf.len(),
             },
@@ -43,7 +44,7 @@ impl<'a> IoSlice<'a> {
 
 #[repr(transparent)]
 pub struct IoSliceMut<'a> {
-    vec: __wasi_iovec_t,
+    vec: wasi::IoVec,
     _p: PhantomData<&'a mut [u8]>,
 }
 
@@ -51,7 +52,7 @@ impl<'a> IoSliceMut<'a> {
     #[inline]
     pub fn new(buf: &'a mut [u8]) -> IoSliceMut<'a> {
         IoSliceMut {
-            vec: __wasi_iovec_t {
+            vec: wasi::IoVec {
                 buf: buf.as_mut_ptr() as *mut c_void,
                 buf_len: buf.len()
             },
diff --git a/src/libstd/sys/wasi/mod.rs b/src/libstd/sys/wasi/mod.rs
index f842869e08ee6..0a16c29e5af53 100644
--- a/src/libstd/sys/wasi/mod.rs
+++ b/src/libstd/sys/wasi/mod.rs
@@ -14,10 +14,10 @@
 //! compiling for wasm. That way it's a compile time error for something that's
 //! guaranteed to be a runtime error!
 
-use libc;
-use crate::io::{Error, ErrorKind};
+use crate::io;
 use crate::mem;
 use crate::os::raw::c_char;
+use wasi::wasi_unstable as wasi;
 
 pub mod alloc;
 pub mod args;
@@ -60,12 +60,12 @@ pub fn unsupported<T>() -> crate::io::Result<T> {
     Err(unsupported_err())
 }
 
-pub fn unsupported_err() -> Error {
-    Error::new(ErrorKind::Other, "operation not supported on wasm yet")
+pub fn unsupported_err() -> io::Error {
+    io::Error::new(io::ErrorKind::Other, "operation not supported on wasm yet")
 }
 
-pub fn decode_error_kind(_code: i32) -> ErrorKind {
-    ErrorKind::Other
+pub fn decode_error_kind(_code: i32) -> io::ErrorKind {
+    io::ErrorKind::Other
 }
 
 // This enum is used as the storage for a bunch of types which can't actually
@@ -83,15 +83,18 @@ pub unsafe fn strlen(mut s: *const c_char) -> usize {
 }
 
 pub unsafe fn abort_internal() -> ! {
-    libc::abort()
+    wasi::proc_exit(127)
 }
 
 pub fn hashmap_random_keys() -> (u64, u64) {
     let mut ret = (0u64, 0u64);
     unsafe {
-        let base = &mut ret as *mut (u64, u64) as *mut libc::c_void;
+        let base = &mut ret as *mut (u64, u64) as *mut core::ffi::c_void;
         let len = mem::size_of_val(&ret);
-        cvt_wasi(libc::__wasi_random_get(base, len)).unwrap();
+        let ret = wasi::raw::__wasi_random_get(base, len);
+        if ret != 0 {
+            panic!("__wasi_random_get failure")
+        }
     }
     return ret
 }
@@ -113,16 +116,14 @@ impl_is_minus_one! { i8 i16 i32 i64 isize }
 
 pub fn cvt<T: IsMinusOne>(t: T) -> crate::io::Result<T> {
     if t.is_minus_one() {
-        Err(Error::last_os_error())
+        Err(io::Error::last_os_error())
     } else {
         Ok(t)
     }
 }
 
-pub fn cvt_wasi(r: u16) -> crate::io::Result<()> {
-    if r != libc::__WASI_ESUCCESS {
-        Err(Error::from_raw_os_error(r as i32))
-    } else {
-        Ok(())
+impl From<wasi::Error> for io::Error {
+    fn from(err: wasi::Error) -> Self {
+        Self::from_raw_os_error(err as i32)
     }
 }
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 822ea02a11b89..026ff71de345b 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -12,6 +12,8 @@ use crate::sys::memchr;
 use crate::sys::{cvt, unsupported, Void};
 use crate::vec;
 
+use wasi::wasi_unstable as wasi;
+
 #[cfg(not(target_feature = "atomics"))]
 pub unsafe fn env_lock() -> impl Any {
     // No need for a lock if we're single-threaded, but this function will need
@@ -19,29 +21,11 @@ pub unsafe fn env_lock() -> impl Any {
 }
 
 pub fn errno() -> i32 {
-    extern {
-        #[thread_local]
-        static errno: libc::c_int;
-    }
-
-    unsafe { errno as i32 }
+    panic!("unsupported")
 }
 
 pub fn error_string(errno: i32) -> String {
-    extern {
-        fn strerror_r(errnum: libc::c_int, buf: *mut libc::c_char,
-                      buflen: libc::size_t) -> libc::c_int;
-    }
-
-    let mut buf = [0 as libc::c_char; 1024];
-
-    let p = buf.as_mut_ptr();
-    unsafe {
-        if strerror_r(errno as libc::c_int, p, buf.len()) < 0 {
-            panic!("strerror_r failure");
-        }
-        str::from_utf8(CStr::from_ptr(p).to_bytes()).unwrap().to_owned()
-    }
+    wasi::error_string(errno).to_string()
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {
@@ -105,6 +89,7 @@ impl Iterator for Env {
 pub fn env() -> Env {
     unsafe {
         let _guard = env_lock();
+        // FIXME: replace with wasi::environ_get
         let mut environ = libc::environ;
         let mut result = Vec::new();
         while environ != ptr::null_mut() && *environ != ptr::null_mut() {
@@ -174,9 +159,7 @@ pub fn home_dir() -> Option<PathBuf> {
 }
 
 pub fn exit(code: i32) -> ! {
-    unsafe {
-        libc::exit(code)
-    }
+    unsafe { wasi::proc_exit(code as u32) }
 }
 
 pub fn getpid() -> u32 {
diff --git a/src/libstd/sys/wasi/stdio.rs b/src/libstd/sys/wasi/stdio.rs
index 2bf8d803c01bb..dc6a6ef375a1c 100644
--- a/src/libstd/sys/wasi/stdio.rs
+++ b/src/libstd/sys/wasi/stdio.rs
@@ -1,8 +1,9 @@
 use crate::io::{self, IoSlice, IoSliceMut};
-use crate::libc;
 use crate::mem::ManuallyDrop;
 use crate::sys::fd::WasiFd;
 
+use wasi::wasi_unstable as wasi;
+
 pub struct Stdin;
 pub struct Stdout;
 pub struct Stderr;
@@ -17,7 +18,7 @@ impl Stdin {
     }
 
     pub fn read_vectored(&self, data: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        ManuallyDrop::new(unsafe { WasiFd::from_raw(libc::STDIN_FILENO as u32) })
+        ManuallyDrop::new(unsafe { WasiFd::from_raw(wasi::STDIN_FD) })
             .read(data)
     }
 }
@@ -32,7 +33,7 @@ impl Stdout {
     }
 
     pub fn write_vectored(&self, data: &[IoSlice<'_>]) -> io::Result<usize> {
-        ManuallyDrop::new(unsafe { WasiFd::from_raw(libc::STDOUT_FILENO as u32) })
+        ManuallyDrop::new(unsafe { WasiFd::from_raw(wasi::STDOUT_FD) })
             .write(data)
     }
 
@@ -51,7 +52,7 @@ impl Stderr {
     }
 
     pub fn write_vectored(&self, data: &[IoSlice<'_>]) -> io::Result<usize> {
-        ManuallyDrop::new(unsafe { WasiFd::from_raw(libc::STDERR_FILENO as u32) })
+        ManuallyDrop::new(unsafe { WasiFd::from_raw(wasi::STDERR_FD) })
             .write(data)
     }
 
@@ -73,7 +74,7 @@ impl io::Write for Stderr {
 pub const STDIN_BUF_SIZE: usize = crate::sys_common::io::DEFAULT_BUF_SIZE;
 
 pub fn is_ebadf(err: &io::Error) -> bool {
-    err.raw_os_error() == Some(libc::__WASI_EBADF as i32)
+    err.raw_os_error() == Some(wasi::EBADF as i32)
 }
 
 pub fn panic_output() -> Option<impl io::Write> {
diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index 5e69e4d948fee..9e0726432d9c4 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -19,8 +19,8 @@ impl Thread {
     }
 
     pub fn yield_now() {
-        let ret = unsafe { libc::__wasi_sched_yield() };
-        debug_assert_eq!(ret, 0);
+        let ret = wasi::sched_yield();
+        debug_assert_eq!(ret, Ok(()));
     }
 
     pub fn set_name(_name: &CStr) {
diff --git a/src/libstd/sys/wasi/time.rs b/src/libstd/sys/wasi/time.rs
index 3f14c80928c67..4c89a1781b9ef 100644
--- a/src/libstd/sys/wasi/time.rs
+++ b/src/libstd/sys/wasi/time.rs
@@ -1,7 +1,6 @@
 use crate::time::Duration;
 use crate::mem;
-use crate::sys::cvt_wasi;
-use libc;
+use wasi::wasi_unstable as wasi;
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Instant(Duration);
@@ -12,23 +11,19 @@ pub struct SystemTime(Duration);
 pub const UNIX_EPOCH: SystemTime = SystemTime(Duration::from_secs(0));
 
 fn current_time(clock: u32) -> Duration {
-    unsafe {
-        let mut ts = mem::zeroed();
-        cvt_wasi(libc::__wasi_clock_time_get(
-            clock,
-            1, // precision... seems ignored though?
-            &mut ts,
-        )).unwrap();
-        Duration::new(
-            (ts / 1_000_000_000) as u64,
-            (ts % 1_000_000_000) as u32,
-        )
-    }
+    let ts = wasi::clock_time_get(
+        clock,
+        1, // precision... seems ignored though?
+    ).unwrap();
+    Duration::new(
+        (ts / 1_000_000_000) as u64,
+        (ts % 1_000_000_000) as u32,
+    )
 }
 
 impl Instant {
     pub fn now() -> Instant {
-        Instant(current_time(libc::__WASI_CLOCK_MONOTONIC))
+        Instant(current_time(wasi::CLOCK_MONOTONIC))
     }
 
     pub const fn zero() -> Instant {
@@ -54,10 +49,10 @@ impl Instant {
 
 impl SystemTime {
     pub fn now() -> SystemTime {
-        SystemTime(current_time(libc::__WASI_CLOCK_REALTIME))
+        SystemTime(current_time(wasi::CLOCK_REALTIME))
     }
 
-    pub fn from_wasi_timestamp(ts: libc::__wasi_timestamp_t) -> SystemTime {
+    pub fn from_wasi_timestamp(ts: wasi::Timestamp) -> SystemTime {
         SystemTime(Duration::from_nanos(ts))
     }
 

From 23cc850ff18652c7b75fa423f9dfff5526a239a7 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 10:44:08 +0300
Subject: [PATCH 02/21] return 0 from errno function

---
 src/libstd/sys/wasi/os.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 026ff71de345b..8411878eeccd9 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -21,7 +21,7 @@ pub unsafe fn env_lock() -> impl Any {
 }
 
 pub fn errno() -> i32 {
-    panic!("unsupported")
+    0
 }
 
 pub fn error_string(errno: i32) -> String {

From cb52065d55e5ba1383aa155880a5e6661e6415a7 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 13:31:41 +0300
Subject: [PATCH 03/21] replace libc::nanosleep with wasi::poll_oneoff

---
 src/libstd/sys/wasi/thread.rs | 37 ++++++++++++++++++++++-------------
 1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index 9e0726432d9c4..eedc584dde500 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -1,7 +1,7 @@
 use crate::cmp;
 use crate::ffi::CStr;
 use crate::io;
-use crate::sys::cvt;
+use crate::mem;
 use crate::sys::{unsupported, Void};
 use crate::time::Duration;
 use libc;
@@ -28,19 +28,28 @@ impl Thread {
     }
 
     pub fn sleep(dur: Duration) {
-        let mut secs = dur.as_secs();
-        let mut nsecs = dur.subsec_nanos() as i32;
-
-        unsafe {
-            while secs > 0 || nsecs > 0 {
-                let mut ts = libc::timespec {
-                    tv_sec: cmp::min(libc::time_t::max_value() as u64, secs) as libc::time_t,
-                    tv_nsec: nsecs,
-                };
-                secs -= ts.tv_sec as u64;
-                cvt(libc::nanosleep(&ts, &mut ts)).unwrap();
-                nsecs = 0;
-            }
+        let nanos = dur.as_nanos();
+        assert!(nanos <= u64::max_value() as u128);
+
+        let clock = wasi::raw::__wasi_subscription_u_clock_t {
+            identifier: 0,
+            clock_id: wasi::CLOCK_MONOTONIC,
+            timeout: nanos as u64,
+            precision: 0,
+            flags: 0,
+        };
+
+        let in_ = [wasi::Subscription {
+            userdata: 0,
+            type_: wasi::EVENTTYPE_CLOCK,
+            u: wasi::raw::__wasi_subscription_u { clock: clock },
+        }];
+        let mut out: [wasi::Event; 1] = [unsafe { mem::zeroed() }];
+        let n = wasi::poll_oneoff(&in_, &mut out).unwrap();
+        let wasi::Event { userdata, error, type_, .. } = out[0];
+        match (n, userdata, error) {
+            (1, 0, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
+            _ => panic!("thread::sleep(): unexpected result of poll_oneof"),
         }
     }
 

From 75a553fa27ffa293a21be5c5138b2b9fd69adfd2 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 13:50:22 +0300
Subject: [PATCH 04/21] remove to_string

---
 src/libstd/sys/wasi/os.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 8411878eeccd9..091ff3480bf85 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -25,7 +25,7 @@ pub fn errno() -> i32 {
 }
 
 pub fn error_string(errno: i32) -> String {
-    wasi::error_string(errno).to_string()
+    wasi::error_string(errno)
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {

From 7a4f0aece871f9850f83db4760a6fea4f595dc8d Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 14:54:37 +0300
Subject: [PATCH 05/21] use wasi::get_args

---
 src/libstd/sys/wasi/args.rs | 42 +++++--------------------------------
 1 file changed, 5 insertions(+), 37 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index 679bb1b2cbe30..e2fe0548f1266 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -13,47 +13,15 @@ pub unsafe fn cleanup() {
 }
 
 pub struct Args {
-    iter: vec::IntoIter<OsString>,
+    iter: vec::IntoIter<Vec<u8>>,
     _dont_send_or_sync_me: PhantomData<*mut ()>,
 }
 
 /// Returns the command line arguments
 pub fn args() -> Args {
-    maybe_args().unwrap_or_else(|_| {
-        Args {
-            iter: Vec::new().into_iter(),
-            _dont_send_or_sync_me: PhantomData
-        }
-    })
-}
-
-fn cvt_wasi(r: u16) -> crate::io::Result<()> {
-    if r != 0 {
-        Err(Error::from_raw_os_error(r as i32))
-    } else {
-        Ok(())
-    }
-}
-
-fn maybe_args() -> io::Result<Args> {
-    // FIXME: replace with safe functions
-    use wasi::wasi_unstable::raw::{__wasi_args_sizes_get, __wasi_args_get};
-    unsafe {
-        let (mut argc, mut argv_buf_size) = (0, 0);
-        cvt_wasi(__wasi_args_sizes_get(&mut argc, &mut argv_buf_size))?;
-
-        let mut argc = vec![core::ptr::null_mut::<u8>(); argc];
-        let mut argv_buf = vec![0; argv_buf_size];
-        cvt_wasi(__wasi_args_get(argc.as_mut_ptr(), argv_buf.as_mut_ptr()))?;
-
-        let args = argc.into_iter()
-            .map(|ptr| CStr::from_ptr(ptr).to_bytes().to_vec())
-            .map(|bytes| OsString::from_vec(bytes))
-            .collect::<Vec<_>>();
-        Ok(Args {
-            iter: args.into_iter(),
-            _dont_send_or_sync_me: PhantomData,
-        })
+    Args {
+        iter: wasi::get_args().unwrap_or(Vec::new()),
+        _dont_send_or_sync_me: PhantomData
     }
 }
 
@@ -66,7 +34,7 @@ impl Args {
 impl Iterator for Args {
     type Item = OsString;
     fn next(&mut self) -> Option<OsString> {
-        self.iter.next()
+        self.iter.next().map(OsString::from_vec)
     }
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()

From 52d2871e10202279b7039f4ad6d4485093fb99cc Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 15:18:02 +0300
Subject: [PATCH 06/21] use wasi::get_environ

---
 src/libstd/sys/wasi/args.rs |  1 -
 src/libstd/sys/wasi/os.rs   | 46 ++++++++++++++-----------------------
 2 files changed, 17 insertions(+), 30 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index e2fe0548f1266..23ab2051bf6f6 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -1,6 +1,5 @@
 use crate::ffi::CStr;
 use crate::io;
-use crate::sys::cvt_wasi;
 use crate::ffi::OsString;
 use crate::marker::PhantomData;
 use crate::os::wasi::ffi::OsStringExt;
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 091ff3480bf85..65c80c838dc82 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -75,45 +75,33 @@ pub fn current_exe() -> io::Result<PathBuf> {
 }
 
 pub struct Env {
-    iter: vec::IntoIter<(OsString, OsString)>,
+    iter: Vec<Vec<u8>>,
     _dont_send_or_sync_me: PhantomData<*mut ()>,
 }
 
 impl Iterator for Env {
     type Item = (OsString, OsString);
-    fn next(&mut self) -> Option<(OsString, OsString)> { self.iter.next() }
+    fn next(&mut self) -> Option<(OsString, OsString)> {
+        self.iter.next().and_then(|input| {
+            // See src/libstd/sys/unix/os.rs, same as that
+            if input.is_empty() {
+                return None;
+            }
+            let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
+            pos.map(|p| (
+                OsStringExt::from_vec(input[..p].to_vec()),
+                OsStringExt::from_vec(input[p+1..].to_vec()),
+            ))
+        })
+    }
     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 }
 
 
 pub fn env() -> Env {
-    unsafe {
-        let _guard = env_lock();
-        // FIXME: replace with wasi::environ_get
-        let mut environ = libc::environ;
-        let mut result = Vec::new();
-        while environ != ptr::null_mut() && *environ != ptr::null_mut() {
-            if let Some(key_value) = parse(CStr::from_ptr(*environ).to_bytes()) {
-                result.push(key_value);
-            }
-            environ = environ.offset(1);
-        }
-        return Env {
-            iter: result.into_iter(),
-            _dont_send_or_sync_me: PhantomData,
-        }
-    }
-
-    // See src/libstd/sys/unix/os.rs, same as that
-    fn parse(input: &[u8]) -> Option<(OsString, OsString)> {
-        if input.is_empty() {
-            return None;
-        }
-        let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
-        pos.map(|p| (
-            OsStringExt::from_vec(input[..p].to_vec()),
-            OsStringExt::from_vec(input[p+1..].to_vec()),
-        ))
+    Env {
+        iter: wasi::get_environ().unwrap_or(Vec::new()),
+        _dont_send_or_sync_me: PhantomData,
     }
 }
 

From 8394dbba7a46cd480b0934331b2654663d487e7b Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 15:18:39 +0300
Subject: [PATCH 07/21] remove libc import

---
 src/libstd/sys/wasi/thread.rs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index eedc584dde500..a399d1f844cb0 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -4,7 +4,6 @@ use crate::io;
 use crate::mem;
 use crate::sys::{unsupported, Void};
 use crate::time::Duration;
-use libc;
 
 pub struct Thread(Void);
 

From 338fc7d042ac868e2c92bfedf2b6850bac1970c9 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 15:32:37 +0300
Subject: [PATCH 08/21] use non-zero clock id

---
 src/libstd/sys/wasi/thread.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index a399d1f844cb0..7a2246de86c4f 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -31,7 +31,7 @@ impl Thread {
         assert!(nanos <= u64::max_value() as u128);
 
         let clock = wasi::raw::__wasi_subscription_u_clock_t {
-            identifier: 0,
+            identifier: 0x0123_45678,
             clock_id: wasi::CLOCK_MONOTONIC,
             timeout: nanos as u64,
             precision: 0,
@@ -47,7 +47,7 @@ impl Thread {
         let n = wasi::poll_oneoff(&in_, &mut out).unwrap();
         let wasi::Event { userdata, error, type_, .. } = out[0];
         match (n, userdata, error) {
-            (1, 0, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
+            (1, 0x0123_45678, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
             _ => panic!("thread::sleep(): unexpected result of poll_oneof"),
         }
     }

From 7658a13c650e3dd931250f6039c4f12bcc77534f Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 15:33:05 +0300
Subject: [PATCH 09/21] typo fix

---
 src/libstd/sys/wasi/thread.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index 7a2246de86c4f..f9e2433dca064 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -48,7 +48,7 @@ impl Thread {
         let wasi::Event { userdata, error, type_, .. } = out[0];
         match (n, userdata, error) {
             (1, 0x0123_45678, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
-            _ => panic!("thread::sleep(): unexpected result of poll_oneof"),
+            _ => panic!("thread::sleep(): unexpected result of poll_oneoff"),
         }
     }
 

From e5ba80a87c54ab7770d9c300dacd0976f74e563e Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 15:36:30 +0300
Subject: [PATCH 10/21] use const

---
 src/libstd/sys/wasi/thread.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index f9e2433dca064..a6c8f2487013b 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -30,8 +30,10 @@ impl Thread {
         let nanos = dur.as_nanos();
         assert!(nanos <= u64::max_value() as u128);
 
+        const CLOCK_ID: wasi::Userdata = 0x0123_45678;
+
         let clock = wasi::raw::__wasi_subscription_u_clock_t {
-            identifier: 0x0123_45678,
+            identifier: CLOCK_ID,
             clock_id: wasi::CLOCK_MONOTONIC,
             timeout: nanos as u64,
             precision: 0,
@@ -47,7 +49,7 @@ impl Thread {
         let n = wasi::poll_oneoff(&in_, &mut out).unwrap();
         let wasi::Event { userdata, error, type_, .. } = out[0];
         match (n, userdata, error) {
-            (1, 0x0123_45678, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
+            (1, CLOCK_ID, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
             _ => panic!("thread::sleep(): unexpected result of poll_oneoff"),
         }
     }

From c05237686f994144f2f0bae68dc5b337b06e9a97 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Mon, 19 Aug 2019 16:01:21 +0300
Subject: [PATCH 11/21] fix

---
 src/libstd/sys/wasi/args.rs | 2 +-
 src/libstd/sys/wasi/os.rs   | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index 23ab2051bf6f6..14aa391912ed2 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -19,7 +19,7 @@ pub struct Args {
 /// Returns the command line arguments
 pub fn args() -> Args {
     Args {
-        iter: wasi::get_args().unwrap_or(Vec::new()),
+        iter: wasi::get_args().unwrap_or(Vec::new()).into_iter(),
         _dont_send_or_sync_me: PhantomData
     }
 }
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 65c80c838dc82..04eee3ef28ff1 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -75,7 +75,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
 }
 
 pub struct Env {
-    iter: Vec<Vec<u8>>,
+    iter: vec::IntoIter<Vec<u8>>,
     _dont_send_or_sync_me: PhantomData<*mut ()>,
 }
 
@@ -100,7 +100,7 @@ impl Iterator for Env {
 
 pub fn env() -> Env {
     Env {
-        iter: wasi::get_environ().unwrap_or(Vec::new()),
+        iter: wasi::get_environ().unwrap_or(Vec::new()).into_iter(),
         _dont_send_or_sync_me: PhantomData,
     }
 }

From 744442d19a76c4dd39f5fa2a2bbd74638e8569ec Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Tue, 20 Aug 2019 15:43:34 +0300
Subject: [PATCH 12/21] fix C incompatibilities

---
 src/libstd/sys/wasi/mod.rs |  2 +-
 src/libstd/sys/wasi/os.rs  | 67 ++++++++++++++++++++++++++------------
 2 files changed, 47 insertions(+), 22 deletions(-)

diff --git a/src/libstd/sys/wasi/mod.rs b/src/libstd/sys/wasi/mod.rs
index 0a16c29e5af53..28b49996d1433 100644
--- a/src/libstd/sys/wasi/mod.rs
+++ b/src/libstd/sys/wasi/mod.rs
@@ -83,7 +83,7 @@ pub unsafe fn strlen(mut s: *const c_char) -> usize {
 }
 
 pub unsafe fn abort_internal() -> ! {
-    wasi::proc_exit(127)
+    libc::abort()
 }
 
 pub fn hashmap_random_keys() -> (u64, u64) {
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 04eee3ef28ff1..dca58179e0c8d 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -21,11 +21,24 @@ pub unsafe fn env_lock() -> impl Any {
 }
 
 pub fn errno() -> i32 {
-    0
+    extern {
+        #[thread_local]
+        static errno: libc::c_int;
+    }
+
+    unsafe { errno as i32 }
 }
 
 pub fn error_string(errno: i32) -> String {
-    wasi::error_string(errno)
+    let mut buf = [0 as libc::c_char; 1024];
+
+    let p = buf.as_mut_ptr();
+    unsafe {
+        if libc::strerror_r(errno as libc::c_int, p, buf.len()) < 0 {
+            panic!("strerror_r failure");
+        }
+        str::from_utf8(CStr::from_ptr(p).to_bytes()).unwrap().to_owned()
+    }
 }
 
 pub fn getcwd() -> io::Result<PathBuf> {
@@ -73,35 +86,45 @@ impl StdError for JoinPathsError {
 pub fn current_exe() -> io::Result<PathBuf> {
     unsupported()
 }
-
 pub struct Env {
-    iter: vec::IntoIter<Vec<u8>>,
+    iter: vec::IntoIter<(OsString, OsString)>,
     _dont_send_or_sync_me: PhantomData<*mut ()>,
 }
 
 impl Iterator for Env {
     type Item = (OsString, OsString);
-    fn next(&mut self) -> Option<(OsString, OsString)> {
-        self.iter.next().and_then(|input| {
-            // See src/libstd/sys/unix/os.rs, same as that
-            if input.is_empty() {
-                return None;
-            }
-            let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
-            pos.map(|p| (
-                OsStringExt::from_vec(input[..p].to_vec()),
-                OsStringExt::from_vec(input[p+1..].to_vec()),
-            ))
-        })
-    }
+    fn next(&mut self) -> Option<(OsString, OsString)> { self.iter.next() }
     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 }
 
 
 pub fn env() -> Env {
-    Env {
-        iter: wasi::get_environ().unwrap_or(Vec::new()).into_iter(),
-        _dont_send_or_sync_me: PhantomData,
+    unsafe {
+        let _guard = env_lock();
+        let mut environ = libc::environ;
+        let mut result = Vec::new();
+        while environ != ptr::null_mut() && *environ != ptr::null_mut() {
+            if let Some(key_value) = parse(CStr::from_ptr(*environ).to_bytes()) {
+                result.push(key_value);
+            }
+            environ = environ.offset(1);
+        }
+        return Env {
+            iter: result.into_iter(),
+            _dont_send_or_sync_me: PhantomData,
+        }
+    }
+
+    // See src/libstd/sys/unix/os.rs, same as that
+    fn parse(input: &[u8]) -> Option<(OsString, OsString)> {
+        if input.is_empty() {
+            return None;
+        }
+        let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
+        pos.map(|p| (
+            OsStringExt::from_vec(input[..p].to_vec()),
+            OsStringExt::from_vec(input[p+1..].to_vec()),
+        ))
     }
 }
 
@@ -147,7 +170,9 @@ pub fn home_dir() -> Option<PathBuf> {
 }
 
 pub fn exit(code: i32) -> ! {
-    unsafe { wasi::proc_exit(code as u32) }
+    unsafe {
+        libc::exit(code)
+    }
 }
 
 pub fn getpid() -> u32 {

From 4dee102a67466ca0c95f540aa458f8779f3a1cb5 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Tue, 20 Aug 2019 19:16:01 +0300
Subject: [PATCH 13/21] use new get_args

---
 src/libstd/sys/wasi/args.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index 14aa391912ed2..2d0ddea385afd 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -12,14 +12,16 @@ pub unsafe fn cleanup() {
 }
 
 pub struct Args {
-    iter: vec::IntoIter<Vec<u8>>,
+    iter: vec::IntoIter<OsString>,
     _dont_send_or_sync_me: PhantomData<*mut ()>,
 }
 
 /// Returns the command line arguments
 pub fn args() -> Args {
+    let mut buf = Vec::new();
+    let _ = wasi::get_args(|arg| buf.push(OsString::from_vec(arg.to_vec())));
     Args {
-        iter: wasi::get_args().unwrap_or(Vec::new()).into_iter(),
+        iter: buf.into_iter(),
         _dont_send_or_sync_me: PhantomData
     }
 }
@@ -33,7 +35,7 @@ impl Args {
 impl Iterator for Args {
     type Item = OsString;
     fn next(&mut self) -> Option<OsString> {
-        self.iter.next().map(OsString::from_vec)
+        self.iter.next()
     }
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()

From 88fd9450aa2111fcbe981006a9c391d57775ec14 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Wed, 21 Aug 2019 04:16:05 +0300
Subject: [PATCH 14/21] update args

---
 src/libstd/sys/wasi/args.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index 2d0ddea385afd..de9ca62469d5d 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -18,8 +18,14 @@ pub struct Args {
 
 /// Returns the command line arguments
 pub fn args() -> Args {
-    let mut buf = Vec::new();
-    let _ = wasi::get_args(|arg| buf.push(OsString::from_vec(arg.to_vec())));
+    let buf = wasi::args_sizes_get().and_then(|args_sizes| {
+        let mut buf = Vec::with_capacity(args_sizes.get_count());
+        wasi::get_args(args_sizes, |arg| {
+            let arg = OsString::from_vec(arg.to_vec());
+            buf.push(arg);
+        })?;
+        Ok(buf)
+    }).unwrap_or(vec![]);
     Args {
         iter: buf.into_iter(),
         _dont_send_or_sync_me: PhantomData

From a47e3c077cd7f201dbbf12140c12663df0fcda6f Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Wed, 21 Aug 2019 17:57:22 +0300
Subject: [PATCH 15/21] fixes

---
 src/libstd/sys/wasi/args.rs   |  6 +--
 src/libstd/sys/wasi/ext/fs.rs |  2 +
 src/libstd/sys/wasi/ext/io.rs |  2 +-
 src/libstd/sys/wasi/fd.rs     | 76 +++++++++++++++++------------------
 src/libstd/sys/wasi/fs.rs     | 16 +++-----
 src/libstd/sys/wasi/io.rs     |  2 +-
 src/libstd/sys/wasi/mod.rs    | 27 +++++++------
 src/libstd/sys/wasi/os.rs     |  2 -
 src/libstd/sys/wasi/stdio.rs  |  4 +-
 src/libstd/sys/wasi/thread.rs |  3 +-
 src/libstd/sys/wasi/time.rs   |  3 +-
 11 files changed, 69 insertions(+), 74 deletions(-)

diff --git a/src/libstd/sys/wasi/args.rs b/src/libstd/sys/wasi/args.rs
index de9ca62469d5d..3280c4990dc66 100644
--- a/src/libstd/sys/wasi/args.rs
+++ b/src/libstd/sys/wasi/args.rs
@@ -1,10 +1,10 @@
-use crate::ffi::CStr;
-use crate::io;
 use crate::ffi::OsString;
 use crate::marker::PhantomData;
 use crate::os::wasi::ffi::OsStringExt;
 use crate::vec;
 
+use ::wasi::wasi_unstable as wasi;
+
 pub unsafe fn init(_argc: isize, _argv: *const *const u8) {
 }
 
@@ -20,7 +20,7 @@ pub struct Args {
 pub fn args() -> Args {
     let buf = wasi::args_sizes_get().and_then(|args_sizes| {
         let mut buf = Vec::with_capacity(args_sizes.get_count());
-        wasi::get_args(args_sizes, |arg| {
+        wasi::args_get(args_sizes, |arg| {
             let arg = OsString::from_vec(arg.to_vec());
             buf.push(arg);
         })?;
diff --git a/src/libstd/sys/wasi/ext/fs.rs b/src/libstd/sys/wasi/ext/fs.rs
index ecd509f01dabd..9fa4abfd171b5 100644
--- a/src/libstd/sys/wasi/ext/fs.rs
+++ b/src/libstd/sys/wasi/ext/fs.rs
@@ -8,6 +8,8 @@ use crate::os::wasi::ffi::OsStrExt;
 use crate::path::{Path, PathBuf};
 use crate::sys_common::{AsInner, AsInnerMut, FromInner};
 
+use ::wasi::wasi_unstable as wasi;
+
 /// WASI-specific extensions to [`File`].
 ///
 /// [`File`]: ../../../../std/fs/struct.File.html
diff --git a/src/libstd/sys/wasi/ext/io.rs b/src/libstd/sys/wasi/ext/io.rs
index c843144f0c406..f1839df380112 100644
--- a/src/libstd/sys/wasi/ext/io.rs
+++ b/src/libstd/sys/wasi/ext/io.rs
@@ -8,7 +8,7 @@ use crate::sys;
 use crate::net;
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 
 /// Raw file descriptors.
 pub type RawFd = u32;
diff --git a/src/libstd/sys/wasi/fd.rs b/src/libstd/sys/wasi/fd.rs
index 93fe8add326c8..275e1319be6ad 100644
--- a/src/libstd/sys/wasi/fd.rs
+++ b/src/libstd/sys/wasi/fd.rs
@@ -3,14 +3,15 @@
 use crate::io::{self, IoSlice, IoSliceMut, SeekFrom};
 use crate::mem;
 use crate::net::Shutdown;
-use wasi::wasi_unstable as wasi;
+use super::err2io;
+use ::wasi::wasi_unstable as wasi;
 
 #[derive(Debug)]
 pub struct WasiFd {
     fd: wasi::Fd,
 }
 
-fn iovec(a: &mut [IoSliceMut<'_>]) -> &[wasi::IoVec] {
+fn iovec<'a>(a: &'a mut [IoSliceMut<'_>]) -> &'a [wasi::IoVec] {
     assert_eq!(
         mem::size_of::<IoSliceMut<'_>>(),
         mem::size_of::<wasi::IoVec>()
@@ -23,7 +24,7 @@ fn iovec(a: &mut [IoSliceMut<'_>]) -> &[wasi::IoVec] {
     unsafe { mem::transmute(a) }
 }
 
-fn ciovec(a: &[IoSlice<'_>]) -> &[wasi::CIoVec] {
+fn ciovec<'a>(a: &'a [IoSlice<'_>]) -> &'a [wasi::CIoVec] {
     assert_eq!(
         mem::size_of::<IoSlice<'_>>(),
         mem::size_of::<wasi::CIoVec>()
@@ -52,23 +53,23 @@ impl WasiFd {
     }
 
     pub fn datasync(&self) -> io::Result<()> {
-        wasi::fd_datasync(self.fd).map_err(From::from)
+        wasi::fd_datasync(self.fd).map_err(err2io)
     }
 
     pub fn pread(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
-        wasi::fd_pread(self.fd, iovec(bufs), offset).map_err(From::from)
+        wasi::fd_pread(self.fd, iovec(bufs), offset).map_err(err2io)
     }
 
     pub fn pwrite(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
-        wasi::fd_pwrite(self.fd, ciovec(bufs), offset).map_err(From::from)
+        wasi::fd_pwrite(self.fd, ciovec(bufs), offset).map_err(err2io)
     }
 
     pub fn read(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        wasi::fd_read(self.fd, iovec(bufs)).map_err(From::from)
+        wasi::fd_read(self.fd, iovec(bufs)).map_err(err2io)
     }
 
     pub fn write(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        wasi::fd_write(self.fd, ciovec(bufs)).map_err(From::from)
+        wasi::fd_write(self.fd, ciovec(bufs)).map_err(err2io)
     }
 
     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
@@ -77,37 +78,37 @@ impl WasiFd {
             SeekFrom::End(pos) => (wasi::WHENCE_END, pos),
             SeekFrom::Current(pos) => (wasi::WHENCE_CUR, pos),
         };
-        wasi::fd_seek(self.fd, offset, whence).map_err(From::from)
+        wasi::fd_seek(self.fd, offset, whence).map_err(err2io)
     }
 
     pub fn tell(&self) -> io::Result<u64> {
-        wasi::fd_tell(self.fd).map_err(From::from)
+        wasi::fd_tell(self.fd).map_err(err2io)
     }
 
     // FIXME: __wasi_fd_fdstat_get
 
     pub fn set_flags(&self, flags: wasi::FdFlags) -> io::Result<()> {
-        wasi::fd_fdstat_set_flags(self.fd, flags).map_err(From::from)
+        wasi::fd_fdstat_set_flags(self.fd, flags).map_err(err2io)
     }
 
     pub fn set_rights(&self, base: wasi::Rights, inheriting: wasi::Rights) -> io::Result<()> {
-        wasi::fd_fdstat_set_rights(self.fd, base, inheriting).map_err(From::from)
+        wasi::fd_fdstat_set_rights(self.fd, base, inheriting).map_err(err2io)
     }
 
     pub fn sync(&self) -> io::Result<()> {
-        wasi::fd_sync(self.fd).map_err(From::from)
+        wasi::fd_sync(self.fd).map_err(err2io)
     }
 
     pub fn advise(&self, offset: u64, len: u64, advice: wasi::Advice) -> io::Result<()> {
-        wasi::fd_advise(self.fd, offset, len, advice).map_err(From::from)
+        wasi::fd_advise(self.fd, offset, len, advice).map_err(err2io)
     }
 
     pub fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
-        wasi::fd_allocate(self.fd, offset, len).map_err(From::from)
+        wasi::fd_allocate(self.fd, offset, len).map_err(err2io)
     }
 
     pub fn create_directory(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_create_directory(self.fd, path).map_err(From::from)
+        wasi::path_create_directory(self.fd, path).map_err(err2io)
     }
 
     pub fn link(
@@ -118,7 +119,7 @@ impl WasiFd {
         new_path: &[u8],
     ) -> io::Result<()> {
         wasi::path_link(self.fd, old_flags, old_path, new_fd.fd, new_path)
-            .map_err(From::from)
+            .map_err(err2io)
     }
 
     pub fn open(
@@ -130,7 +131,7 @@ impl WasiFd {
         fs_rights_inheriting: wasi::Rights,
         fs_flags: wasi::FdFlags,
     ) -> io::Result<WasiFd> {
-        let fd = wasi_path_open(
+        wasi::path_open(
             self.fd,
             dirflags,
             path,
@@ -138,25 +139,24 @@ impl WasiFd {
             fs_rights_base,
             fs_rights_inheriting,
             fs_flags,
-        )?;
-        Ok(WasiFd::from_raw(fd))
+        ).map(|fd| unsafe { WasiFd::from_raw(fd) }).map_err(err2io)
     }
 
     pub fn readdir(&self, buf: &mut [u8], cookie: wasi::DirCookie) -> io::Result<usize> {
-        wasi::fd_readdir(self.fd, buf, cookie).map_err(From::from)
+        wasi::fd_readdir(self.fd, buf, cookie).map_err(err2io)
     }
 
     pub fn readlink(&self, path: &[u8], buf: &mut [u8]) -> io::Result<usize> {
-        wasi::path_readlink(self.fd, path, buf).map_err(From::from)
+        wasi::path_readlink(self.fd, path, buf).map_err(err2io)
     }
 
     pub fn rename(&self, old_path: &[u8], new_fd: &WasiFd, new_path: &[u8]) -> io::Result<()> {
         wasi::path_rename(self.fd, old_path, new_fd.fd, new_path)
-            .map_err(From::from)
+            .map_err(err2io)
     }
 
-    pub fn filestat_get(&self) -> io::Result<wasi::Filestat> {
-        wasi::fd_filestat_get(self.fd, buf).map_err(From::from)
+    pub fn filestat_get(&self) -> io::Result<wasi::FileStat> {
+        wasi::fd_filestat_get(self.fd).map_err(err2io)
     }
 
     pub fn filestat_set_times(
@@ -166,11 +166,11 @@ impl WasiFd {
         fstflags: wasi::FstFlags,
     ) -> io::Result<()> {
         wasi::fd_filestat_set_times(self.fd, atim, mtim, fstflags)
-            .map_err(From::from)
+            .map_err(err2io)
     }
 
     pub fn filestat_set_size(&self, size: u64) -> io::Result<()> {
-        wasi::fd_filestat_set_size(self.fd, size).map_err(From::from)
+        wasi::fd_filestat_set_size(self.fd, size).map_err(err2io)
     }
 
     pub fn path_filestat_get(
@@ -178,7 +178,7 @@ impl WasiFd {
         flags: wasi::LookupFlags,
         path: &[u8],
     ) -> io::Result<wasi::FileStat> {
-        wasi::path_filestat_get(self.fd, flags, path).map_err(From::from)
+        wasi::path_filestat_get(self.fd, flags, path).map_err(err2io)
     }
 
     pub fn path_filestat_set_times(
@@ -196,19 +196,19 @@ impl WasiFd {
             atim,
             mtim,
             fstflags,
-        ).map_err(From::from)
+        ).map_err(err2io)
     }
 
     pub fn symlink(&self, old_path: &[u8], new_path: &[u8]) -> io::Result<()> {
-        wasi::path_symlink(old_path, self.fd, new_path).map_err(From::from)
+        wasi::path_symlink(old_path, self.fd, new_path).map_err(err2io)
     }
 
     pub fn unlink_file(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_unlink_file(self.fd, path).map_err(From::from)
+        wasi::path_unlink_file(self.fd, path).map_err(err2io)
     }
 
     pub fn remove_directory(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_remove_directory(self.fd, path).map_err(From::from)
+        wasi::path_remove_directory(self.fd, path).map_err(err2io)
     }
 
     pub fn sock_recv(
@@ -216,20 +216,20 @@ impl WasiFd {
         ri_data: &mut [IoSliceMut<'_>],
         ri_flags: wasi::RiFlags,
     ) -> io::Result<(usize, wasi::RoFlags)> {
-        wasi::sock_recv(self.fd, iovec(ri_data), ri_flags).map_err(From::from)
+        wasi::sock_recv(self.fd, iovec(ri_data), ri_flags).map_err(err2io)
     }
 
     pub fn sock_send(&self, si_data: &[IoSlice<'_>], si_flags: wasi::SiFlags) -> io::Result<usize> {
-        wasi::sock_send(self.fd, ciovec(si_data), si_flags).map_err(From::from)
+        wasi::sock_send(self.fd, ciovec(si_data), si_flags).map_err(err2io)
     }
 
     pub fn sock_shutdown(&self, how: Shutdown) -> io::Result<()> {
         let how = match how {
-            Shutdown::Read => WASI::SHUT_RD,
-            Shutdown::Write => WASI::SHUT_WR,
-            Shutdown::Both => WASI::SHUT_WR | WASI::SHUT_RD,
+            Shutdown::Read => wasi::SHUT_RD,
+            Shutdown::Write => wasi::SHUT_WR,
+            Shutdown::Both => wasi::SHUT_WR | wasi::SHUT_RD,
         };
-        wasi::sock_shutdown(self.fd, how).map_err(From::from)
+        wasi::sock_shutdown(self.fd, how).map_err(err2io)
     }
 }
 
diff --git a/src/libstd/sys/wasi/fs.rs b/src/libstd/sys/wasi/fs.rs
index f23ecfc2bcd22..4113f6a2e09c0 100644
--- a/src/libstd/sys/wasi/fs.rs
+++ b/src/libstd/sys/wasi/fs.rs
@@ -7,7 +7,7 @@ use crate::os::wasi::ffi::{OsStrExt, OsStringExt};
 use crate::path::{Path, PathBuf};
 use crate::ptr;
 use crate::sync::Arc;
-use crate::sys::fd::{DirCookie, WasiFd};
+use crate::sys::fd::WasiFd;
 use crate::sys::time::SystemTime;
 use crate::sys::unsupported;
 use crate::sys_common::FromInner;
@@ -15,7 +15,7 @@ use crate::sys_common::FromInner;
 pub use crate::sys_common::fs::copy;
 pub use crate::sys_common::fs::remove_dir_all;
 
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 
 pub struct File {
     fd: WasiFd,
@@ -28,7 +28,7 @@ pub struct FileAttr {
 
 pub struct ReadDir {
     inner: Arc<ReadDirInner>,
-    cookie: Option<DirCookie>,
+    cookie: Option<wasi::DirCookie>,
     buf: Vec<u8>,
     offset: usize,
     cap: usize,
@@ -70,12 +70,6 @@ pub struct FileType {
 pub struct DirBuilder {}
 
 impl FileAttr {
-    fn zero() -> FileAttr {
-        FileAttr {
-            meta: unsafe { mem::zeroed() },
-        }
-    }
-
     pub fn size(&self) -> u64 {
         self.meta.st_size
     }
@@ -390,7 +384,7 @@ impl File {
     }
 
     pub fn file_attr(&self) -> io::Result<FileAttr> {
-        self.fd.filestat_get().map_ok(|meta| FileAttr { meta })
+        self.fd.filestat_get().map(|meta| FileAttr { meta })
     }
 
     pub fn metadata_at(
@@ -601,7 +595,7 @@ fn metadata_at(
     path: &Path,
 ) -> io::Result<FileAttr> {
     fd.path_filestat_get(flags, path.as_os_str().as_bytes())
-        .map_ok(|meta| FileAttr { meta })
+        .map(|meta| FileAttr { meta })
 }
 
 pub fn canonicalize(_p: &Path) -> io::Result<PathBuf> {
diff --git a/src/libstd/sys/wasi/io.rs b/src/libstd/sys/wasi/io.rs
index ebea3a03e439f..4be92faed308f 100644
--- a/src/libstd/sys/wasi/io.rs
+++ b/src/libstd/sys/wasi/io.rs
@@ -1,7 +1,7 @@
 use crate::marker::PhantomData;
 use crate::slice;
 
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 use core::ffi::c_void;
 
 #[repr(transparent)]
diff --git a/src/libstd/sys/wasi/mod.rs b/src/libstd/sys/wasi/mod.rs
index 28b49996d1433..89f7c887aafc0 100644
--- a/src/libstd/sys/wasi/mod.rs
+++ b/src/libstd/sys/wasi/mod.rs
@@ -14,10 +14,10 @@
 //! compiling for wasm. That way it's a compile time error for something that's
 //! guaranteed to be a runtime error!
 
-use crate::io;
+use crate::io as std_io;
 use crate::mem;
 use crate::os::raw::c_char;
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 
 pub mod alloc;
 pub mod args;
@@ -56,16 +56,19 @@ pub mod ext;
 pub fn init() {
 }
 
-pub fn unsupported<T>() -> crate::io::Result<T> {
+pub fn unsupported<T>() -> std_io::Result<T> {
     Err(unsupported_err())
 }
 
-pub fn unsupported_err() -> io::Error {
-    io::Error::new(io::ErrorKind::Other, "operation not supported on wasm yet")
+pub fn unsupported_err() -> std_io::Error {
+    std_io::Error::new(
+        std_io::ErrorKind::Other,
+        "operation not supported on wasm yet",
+    )
 }
 
-pub fn decode_error_kind(_code: i32) -> io::ErrorKind {
-    io::ErrorKind::Other
+pub fn decode_error_kind(_code: i32) -> std_io::ErrorKind {
+    std_io::ErrorKind::Other
 }
 
 // This enum is used as the storage for a bunch of types which can't actually
@@ -114,16 +117,14 @@ macro_rules! impl_is_minus_one {
 
 impl_is_minus_one! { i8 i16 i32 i64 isize }
 
-pub fn cvt<T: IsMinusOne>(t: T) -> crate::io::Result<T> {
+pub fn cvt<T: IsMinusOne>(t: T) -> std_io::Result<T> {
     if t.is_minus_one() {
-        Err(io::Error::last_os_error())
+        Err(std_io::Error::last_os_error())
     } else {
         Ok(t)
     }
 }
 
-impl From<wasi::Error> for io::Error {
-    fn from(err: wasi::Error) -> Self {
-        Self::from_raw_os_error(err as i32)
-    }
+fn err2io(err: wasi::Error) -> std_io::Error {
+    std_io::Error::from_raw_os_error(err.get() as i32)
 }
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index dca58179e0c8d..7ee23c9a35ec7 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -12,8 +12,6 @@ use crate::sys::memchr;
 use crate::sys::{cvt, unsupported, Void};
 use crate::vec;
 
-use wasi::wasi_unstable as wasi;
-
 #[cfg(not(target_feature = "atomics"))]
 pub unsafe fn env_lock() -> impl Any {
     // No need for a lock if we're single-threaded, but this function will need
diff --git a/src/libstd/sys/wasi/stdio.rs b/src/libstd/sys/wasi/stdio.rs
index dc6a6ef375a1c..1d57b9922e599 100644
--- a/src/libstd/sys/wasi/stdio.rs
+++ b/src/libstd/sys/wasi/stdio.rs
@@ -2,7 +2,7 @@ use crate::io::{self, IoSlice, IoSliceMut};
 use crate::mem::ManuallyDrop;
 use crate::sys::fd::WasiFd;
 
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 
 pub struct Stdin;
 pub struct Stdout;
@@ -74,7 +74,7 @@ impl io::Write for Stderr {
 pub const STDIN_BUF_SIZE: usize = crate::sys_common::io::DEFAULT_BUF_SIZE;
 
 pub fn is_ebadf(err: &io::Error) -> bool {
-    err.raw_os_error() == Some(wasi::EBADF as i32)
+    err.raw_os_error() == Some(wasi::EBADF.get() as i32)
 }
 
 pub fn panic_output() -> Option<impl io::Write> {
diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index a6c8f2487013b..dc5a72e82a354 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -1,10 +1,11 @@
-use crate::cmp;
 use crate::ffi::CStr;
 use crate::io;
 use crate::mem;
 use crate::sys::{unsupported, Void};
 use crate::time::Duration;
 
+use ::wasi::wasi_unstable as wasi;
+
 pub struct Thread(Void);
 
 pub const DEFAULT_MIN_STACK_SIZE: usize = 4096;
diff --git a/src/libstd/sys/wasi/time.rs b/src/libstd/sys/wasi/time.rs
index 4c89a1781b9ef..4394a22f9c233 100644
--- a/src/libstd/sys/wasi/time.rs
+++ b/src/libstd/sys/wasi/time.rs
@@ -1,6 +1,5 @@
 use crate::time::Duration;
-use crate::mem;
-use wasi::wasi_unstable as wasi;
+use ::wasi::wasi_unstable as wasi;
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Debug, Hash)]
 pub struct Instant(Duration);

From 926f36400f1667edec92959d8b640dea5084674c Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Wed, 21 Aug 2019 19:36:12 +0300
Subject: [PATCH 16/21] move cvt

---
 src/libstd/Cargo.toml      |  1 +
 src/libstd/sys/wasi/mod.rs | 23 -----------------------
 src/libstd/sys/wasi/os.rs  | 25 ++++++++++++++++++++++++-
 3 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index bb77a5bdea493..d801b051357a4 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -24,6 +24,7 @@ compiler_builtins = { version = "0.1.16" }
 profiler_builtins = { path = "../libprofiler_builtins", optional = true }
 unwind = { path = "../libunwind" }
 hashbrown = { version = "0.5.0", features = ['rustc-dep-of-std'] }
+wasi = { git = "https://github.com/newpavlov/rust-wasi", branch = "safe_rework", features = ['rustc-dep-of-std', 'alloc'] }
 
 [dependencies.backtrace]
 version = "0.3.35"
diff --git a/src/libstd/sys/wasi/mod.rs b/src/libstd/sys/wasi/mod.rs
index 89f7c887aafc0..f87e4d16fcdac 100644
--- a/src/libstd/sys/wasi/mod.rs
+++ b/src/libstd/sys/wasi/mod.rs
@@ -102,29 +102,6 @@ pub fn hashmap_random_keys() -> (u64, u64) {
     return ret
 }
 
-#[doc(hidden)]
-pub trait IsMinusOne {
-    fn is_minus_one(&self) -> bool;
-}
-
-macro_rules! impl_is_minus_one {
-    ($($t:ident)*) => ($(impl IsMinusOne for $t {
-        fn is_minus_one(&self) -> bool {
-            *self == -1
-        }
-    })*)
-}
-
-impl_is_minus_one! { i8 i16 i32 i64 isize }
-
-pub fn cvt<T: IsMinusOne>(t: T) -> std_io::Result<T> {
-    if t.is_minus_one() {
-        Err(std_io::Error::last_os_error())
-    } else {
-        Ok(t)
-    }
-}
-
 fn err2io(err: wasi::Error) -> std_io::Error {
     std_io::Error::from_raw_os_error(err.get() as i32)
 }
diff --git a/src/libstd/sys/wasi/os.rs b/src/libstd/sys/wasi/os.rs
index 7ee23c9a35ec7..feee840782550 100644
--- a/src/libstd/sys/wasi/os.rs
+++ b/src/libstd/sys/wasi/os.rs
@@ -9,7 +9,7 @@ use crate::path::{self, PathBuf};
 use crate::ptr;
 use crate::str;
 use crate::sys::memchr;
-use crate::sys::{cvt, unsupported, Void};
+use crate::sys::{unsupported, Void};
 use crate::vec;
 
 #[cfg(not(target_feature = "atomics"))]
@@ -176,3 +176,26 @@ pub fn exit(code: i32) -> ! {
 pub fn getpid() -> u32 {
     panic!("unsupported");
 }
+
+#[doc(hidden)]
+pub trait IsMinusOne {
+    fn is_minus_one(&self) -> bool;
+}
+
+macro_rules! impl_is_minus_one {
+    ($($t:ident)*) => ($(impl IsMinusOne for $t {
+        fn is_minus_one(&self) -> bool {
+            *self == -1
+        }
+    })*)
+}
+
+impl_is_minus_one! { i8 i16 i32 i64 isize }
+
+fn cvt<T: IsMinusOne>(t: T) -> io::Result<T> {
+    if t.is_minus_one() {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(t)
+    }
+}

From 6374b8458f0796a1ff3ee2caec41321e801c35d1 Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Thu, 29 Aug 2019 20:13:15 +0300
Subject: [PATCH 17/21] update to wasi v0.7

---
 Cargo.lock                    |  12 ++++
 src/libstd/Cargo.toml         |   2 +-
 src/libstd/sys/wasi/fd.rs     | 104 ++++++++++++++++++----------------
 src/libstd/sys/wasi/mod.rs    |  13 ++++-
 src/libstd/sys/wasi/thread.rs |   2 +-
 5 files changed, 80 insertions(+), 53 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 8ae21c8663706..3719b36236797 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3866,6 +3866,7 @@ dependencies = [
  "rustc_msan",
  "rustc_tsan",
  "unwind",
+ "wasi",
 ]
 
 [[package]]
@@ -4664,6 +4665,17 @@ dependencies = [
  "try-lock",
 ]
 
+[[package]]
+name = "wasi"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b89c3ce4ce14bdc6fb6beaf9ec7928ca331de5df7e5ea278375642a2f478570d"
+dependencies = [
+ "compiler_builtins",
+ "rustc-std-workspace-alloc",
+ "rustc-std-workspace-core",
+]
+
 [[package]]
 name = "winapi"
 version = "0.2.8"
diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index d801b051357a4..0d04b7a274037 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -24,7 +24,7 @@ compiler_builtins = { version = "0.1.16" }
 profiler_builtins = { path = "../libprofiler_builtins", optional = true }
 unwind = { path = "../libunwind" }
 hashbrown = { version = "0.5.0", features = ['rustc-dep-of-std'] }
-wasi = { git = "https://github.com/newpavlov/rust-wasi", branch = "safe_rework", features = ['rustc-dep-of-std', 'alloc'] }
+wasi = { version = "0.7.0", features = ['rustc-dep-of-std', 'alloc'] }
 
 [dependencies.backtrace]
 version = "0.3.35"
diff --git a/src/libstd/sys/wasi/fd.rs b/src/libstd/sys/wasi/fd.rs
index 275e1319be6ad..5b7a8678b66ea 100644
--- a/src/libstd/sys/wasi/fd.rs
+++ b/src/libstd/sys/wasi/fd.rs
@@ -53,23 +53,23 @@ impl WasiFd {
     }
 
     pub fn datasync(&self) -> io::Result<()> {
-        wasi::fd_datasync(self.fd).map_err(err2io)
+        unsafe { wasi::fd_datasync(self.fd).map_err(err2io) }
     }
 
     pub fn pread(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
-        wasi::fd_pread(self.fd, iovec(bufs), offset).map_err(err2io)
+        unsafe { wasi::fd_pread(self.fd, iovec(bufs), offset).map_err(err2io) }
     }
 
     pub fn pwrite(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
-        wasi::fd_pwrite(self.fd, ciovec(bufs), offset).map_err(err2io)
+        unsafe { wasi::fd_pwrite(self.fd, ciovec(bufs), offset).map_err(err2io) }
     }
 
     pub fn read(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        wasi::fd_read(self.fd, iovec(bufs)).map_err(err2io)
+        unsafe { wasi::fd_read(self.fd, iovec(bufs)).map_err(err2io) }
     }
 
     pub fn write(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        wasi::fd_write(self.fd, ciovec(bufs)).map_err(err2io)
+        unsafe { wasi::fd_write(self.fd, ciovec(bufs)).map_err(err2io) }
     }
 
     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
@@ -78,37 +78,37 @@ impl WasiFd {
             SeekFrom::End(pos) => (wasi::WHENCE_END, pos),
             SeekFrom::Current(pos) => (wasi::WHENCE_CUR, pos),
         };
-        wasi::fd_seek(self.fd, offset, whence).map_err(err2io)
+        unsafe { wasi::fd_seek(self.fd, offset, whence).map_err(err2io) }
     }
 
     pub fn tell(&self) -> io::Result<u64> {
-        wasi::fd_tell(self.fd).map_err(err2io)
+        unsafe { wasi::fd_tell(self.fd).map_err(err2io) }
     }
 
     // FIXME: __wasi_fd_fdstat_get
 
     pub fn set_flags(&self, flags: wasi::FdFlags) -> io::Result<()> {
-        wasi::fd_fdstat_set_flags(self.fd, flags).map_err(err2io)
+        unsafe { wasi::fd_fdstat_set_flags(self.fd, flags).map_err(err2io) }
     }
 
     pub fn set_rights(&self, base: wasi::Rights, inheriting: wasi::Rights) -> io::Result<()> {
-        wasi::fd_fdstat_set_rights(self.fd, base, inheriting).map_err(err2io)
+        unsafe { wasi::fd_fdstat_set_rights(self.fd, base, inheriting).map_err(err2io) }
     }
 
     pub fn sync(&self) -> io::Result<()> {
-        wasi::fd_sync(self.fd).map_err(err2io)
+        unsafe { wasi::fd_sync(self.fd).map_err(err2io) }
     }
 
     pub fn advise(&self, offset: u64, len: u64, advice: wasi::Advice) -> io::Result<()> {
-        wasi::fd_advise(self.fd, offset, len, advice).map_err(err2io)
+        unsafe { wasi::fd_advise(self.fd, offset, len, advice).map_err(err2io) }
     }
 
     pub fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
-        wasi::fd_allocate(self.fd, offset, len).map_err(err2io)
+        unsafe { wasi::fd_allocate(self.fd, offset, len).map_err(err2io) }
     }
 
     pub fn create_directory(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_create_directory(self.fd, path).map_err(err2io)
+        unsafe { wasi::path_create_directory(self.fd, path).map_err(err2io) }
     }
 
     pub fn link(
@@ -118,8 +118,10 @@ impl WasiFd {
         new_fd: &WasiFd,
         new_path: &[u8],
     ) -> io::Result<()> {
-        wasi::path_link(self.fd, old_flags, old_path, new_fd.fd, new_path)
-            .map_err(err2io)
+        unsafe {
+            wasi::path_link(self.fd, old_flags, old_path, new_fd.fd, new_path)
+                .map_err(err2io)
+        }
     }
 
     pub fn open(
@@ -131,32 +133,35 @@ impl WasiFd {
         fs_rights_inheriting: wasi::Rights,
         fs_flags: wasi::FdFlags,
     ) -> io::Result<WasiFd> {
-        wasi::path_open(
-            self.fd,
-            dirflags,
-            path,
-            oflags,
-            fs_rights_base,
-            fs_rights_inheriting,
-            fs_flags,
-        ).map(|fd| unsafe { WasiFd::from_raw(fd) }).map_err(err2io)
+        unsafe {
+            wasi::path_open(
+                self.fd,
+                dirflags,
+                path,
+                oflags,
+                fs_rights_base,
+                fs_rights_inheriting,
+                fs_flags,
+            ).map(|fd| WasiFd::from_raw(fd)).map_err(err2io)
+        }
     }
 
     pub fn readdir(&self, buf: &mut [u8], cookie: wasi::DirCookie) -> io::Result<usize> {
-        wasi::fd_readdir(self.fd, buf, cookie).map_err(err2io)
+        unsafe { wasi::fd_readdir(self.fd, buf, cookie).map_err(err2io) }
     }
 
     pub fn readlink(&self, path: &[u8], buf: &mut [u8]) -> io::Result<usize> {
-        wasi::path_readlink(self.fd, path, buf).map_err(err2io)
+        unsafe { wasi::path_readlink(self.fd, path, buf).map_err(err2io) }
     }
 
     pub fn rename(&self, old_path: &[u8], new_fd: &WasiFd, new_path: &[u8]) -> io::Result<()> {
-        wasi::path_rename(self.fd, old_path, new_fd.fd, new_path)
-            .map_err(err2io)
+        unsafe {
+            wasi::path_rename(self.fd, old_path, new_fd.fd, new_path).map_err(err2io)
+        }
     }
 
     pub fn filestat_get(&self) -> io::Result<wasi::FileStat> {
-        wasi::fd_filestat_get(self.fd).map_err(err2io)
+        unsafe { wasi::fd_filestat_get(self.fd).map_err(err2io) }
     }
 
     pub fn filestat_set_times(
@@ -165,12 +170,13 @@ impl WasiFd {
         mtim: wasi::Timestamp,
         fstflags: wasi::FstFlags,
     ) -> io::Result<()> {
-        wasi::fd_filestat_set_times(self.fd, atim, mtim, fstflags)
-            .map_err(err2io)
+        unsafe {
+            wasi::fd_filestat_set_times(self.fd, atim, mtim, fstflags).map_err(err2io)
+        }
     }
 
     pub fn filestat_set_size(&self, size: u64) -> io::Result<()> {
-        wasi::fd_filestat_set_size(self.fd, size).map_err(err2io)
+        unsafe { wasi::fd_filestat_set_size(self.fd, size).map_err(err2io) }
     }
 
     pub fn path_filestat_get(
@@ -178,7 +184,7 @@ impl WasiFd {
         flags: wasi::LookupFlags,
         path: &[u8],
     ) -> io::Result<wasi::FileStat> {
-        wasi::path_filestat_get(self.fd, flags, path).map_err(err2io)
+        unsafe { wasi::path_filestat_get(self.fd, flags, path).map_err(err2io) }
     }
 
     pub fn path_filestat_set_times(
@@ -189,26 +195,28 @@ impl WasiFd {
         mtim: wasi::Timestamp,
         fstflags: wasi::FstFlags,
     ) -> io::Result<()> {
-        wasi::path_filestat_set_times(
-            self.fd,
-            flags,
-            path,
-            atim,
-            mtim,
-            fstflags,
-        ).map_err(err2io)
+        unsafe {
+            wasi::path_filestat_set_times(
+                self.fd,
+                flags,
+                path,
+                atim,
+                mtim,
+                fstflags,
+            ).map_err(err2io)
+        }
     }
 
     pub fn symlink(&self, old_path: &[u8], new_path: &[u8]) -> io::Result<()> {
-        wasi::path_symlink(old_path, self.fd, new_path).map_err(err2io)
+        unsafe { wasi::path_symlink(old_path, self.fd, new_path).map_err(err2io) }
     }
 
     pub fn unlink_file(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_unlink_file(self.fd, path).map_err(err2io)
+        unsafe { wasi::path_unlink_file(self.fd, path).map_err(err2io) }
     }
 
     pub fn remove_directory(&self, path: &[u8]) -> io::Result<()> {
-        wasi::path_remove_directory(self.fd, path).map_err(err2io)
+        unsafe { wasi::path_remove_directory(self.fd, path).map_err(err2io) }
     }
 
     pub fn sock_recv(
@@ -216,11 +224,11 @@ impl WasiFd {
         ri_data: &mut [IoSliceMut<'_>],
         ri_flags: wasi::RiFlags,
     ) -> io::Result<(usize, wasi::RoFlags)> {
-        wasi::sock_recv(self.fd, iovec(ri_data), ri_flags).map_err(err2io)
+        unsafe { wasi::sock_recv(self.fd, iovec(ri_data), ri_flags).map_err(err2io) }
     }
 
     pub fn sock_send(&self, si_data: &[IoSlice<'_>], si_flags: wasi::SiFlags) -> io::Result<usize> {
-        wasi::sock_send(self.fd, ciovec(si_data), si_flags).map_err(err2io)
+        unsafe { wasi::sock_send(self.fd, ciovec(si_data), si_flags).map_err(err2io) }
     }
 
     pub fn sock_shutdown(&self, how: Shutdown) -> io::Result<()> {
@@ -229,7 +237,7 @@ impl WasiFd {
             Shutdown::Write => wasi::SHUT_WR,
             Shutdown::Both => wasi::SHUT_WR | wasi::SHUT_RD,
         };
-        wasi::sock_shutdown(self.fd, how).map_err(err2io)
+        unsafe { wasi::sock_shutdown(self.fd, how).map_err(err2io) }
     }
 }
 
@@ -237,6 +245,6 @@ impl Drop for WasiFd {
     fn drop(&mut self) {
         // FIXME: can we handle the return code here even though we can't on
         // unix?
-        let _ = wasi::fd_close(self.fd);
+        let _ = unsafe { wasi::fd_close(self.fd) };
     }
 }
diff --git a/src/libstd/sys/wasi/mod.rs b/src/libstd/sys/wasi/mod.rs
index 4007b7ac0ec5f..517e3be9cb58c 100644
--- a/src/libstd/sys/wasi/mod.rs
+++ b/src/libstd/sys/wasi/mod.rs
@@ -69,10 +69,17 @@ pub fn unsupported_err() -> std_io::Error {
 
 pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
     use std_io::ErrorKind::*;
-    match errno as libc::c_int {
+    if errno > u16::max_value() as i32 || errno < 0 {
+        return Other;
+    }
+    let code = match wasi::Error::new(errno as u16) {
+        Some(code) => code,
+        None => return Other,
+    };
+    match code {
         wasi::ECONNREFUSED => ConnectionRefused,
         wasi::ECONNRESET => ConnectionReset,
-        wasi::EPERM | libc::EACCES => PermissionDenied,
+        wasi::EPERM | wasi::EACCES => PermissionDenied,
         wasi::EPIPE => BrokenPipe,
         wasi::ENOTCONN => NotConnected,
         wasi::ECONNABORTED => ConnectionAborted,
@@ -84,7 +91,7 @@ pub fn decode_error_kind(errno: i32) -> std_io::ErrorKind {
         wasi::ETIMEDOUT => TimedOut,
         wasi::EEXIST => AlreadyExists,
         wasi::EAGAIN => WouldBlock,
-        _ => ErrorKind::Other,
+        _ => Other,
     }
 }
 
diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index dc5a72e82a354..987bf7580838b 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -47,7 +47,7 @@ impl Thread {
             u: wasi::raw::__wasi_subscription_u { clock: clock },
         }];
         let mut out: [wasi::Event; 1] = [unsafe { mem::zeroed() }];
-        let n = wasi::poll_oneoff(&in_, &mut out).unwrap();
+        let n = unsafe { wasi::poll_oneoff(&in_, &mut out).unwrap() };
         let wasi::Event { userdata, error, type_, .. } = out[0];
         match (n, userdata, error) {
             (1, CLOCK_ID, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}

From 06acfb22e03ff482275e1ffd78f691b0e5d88ffb Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Thu, 29 Aug 2019 20:22:24 +0300
Subject: [PATCH 18/21] add wasi license to the licenses whitelist

---
 src/tools/tidy/src/deps.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index e07a07234c71e..6ca912db5930d 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -15,6 +15,7 @@ const LICENSES: &[&str] = &[
     "Apache-2.0 / MIT",
     "MIT OR Apache-2.0",
     "Apache-2.0 OR MIT",
+    "Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT", // wasi license
     "MIT",
     "Unlicense/MIT",
     "Unlicense OR MIT",

From 127311b75efd47a6f54aca49523c050566fc9823 Mon Sep 17 00:00:00 2001
From: Artyom Pavlov <newpavlov@gmail.com>
Date: Thu, 29 Aug 2019 18:08:13 +0000
Subject: [PATCH 19/21] whitelist wasi crate

---
 src/tools/tidy/src/deps.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tools/tidy/src/deps.rs b/src/tools/tidy/src/deps.rs
index 6ca912db5930d..c31da3c6f4887 100644
--- a/src/tools/tidy/src/deps.rs
+++ b/src/tools/tidy/src/deps.rs
@@ -172,6 +172,7 @@ const WHITELIST: &[Crate<'_>] = &[
     Crate("vcpkg"),
     Crate("version_check"),
     Crate("void"),
+    Crate("wasi"),
     Crate("winapi"),
     Crate("winapi-build"),
     Crate("winapi-i686-pc-windows-gnu"),

From 9fd203a01e0fe6fb307809fdfdbfcd3bda350cfc Mon Sep 17 00:00:00 2001
From: newpavlov <newpavlov@gmail.com>
Date: Fri, 30 Aug 2019 17:30:33 +0300
Subject: [PATCH 20/21] simplify code

---
 src/libstd/sys/wasi/thread.rs | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/libstd/sys/wasi/thread.rs b/src/libstd/sys/wasi/thread.rs
index 987bf7580838b..28a504f197974 100644
--- a/src/libstd/sys/wasi/thread.rs
+++ b/src/libstd/sys/wasi/thread.rs
@@ -46,11 +46,18 @@ impl Thread {
             type_: wasi::EVENTTYPE_CLOCK,
             u: wasi::raw::__wasi_subscription_u { clock: clock },
         }];
-        let mut out: [wasi::Event; 1] = [unsafe { mem::zeroed() }];
-        let n = unsafe { wasi::poll_oneoff(&in_, &mut out).unwrap() };
-        let wasi::Event { userdata, error, type_, .. } = out[0];
-        match (n, userdata, error) {
-            (1, CLOCK_ID, 0) if type_ == wasi::EVENTTYPE_CLOCK => {}
+        let (res, event) = unsafe {
+            let mut out: [wasi::Event; 1] = mem::zeroed();
+            let res = wasi::poll_oneoff(&in_, &mut out);
+            (res, out[0])
+        };
+        match (res, event) {
+            (Ok(1), wasi::Event {
+                userdata: CLOCK_ID,
+                error: 0,
+                type_: wasi::EVENTTYPE_CLOCK,
+                ..
+            }) => {}
             _ => panic!("thread::sleep(): unexpected result of poll_oneoff"),
         }
     }

From 0662fcf4f950ec2800f0b1e02254ef2389b55079 Mon Sep 17 00:00:00 2001
From: Artyom Pavlov <newpavlov@gmail.com>
Date: Tue, 3 Sep 2019 14:37:53 +0000
Subject: [PATCH 21/21] make wasi a target-specific dependency

---
 src/libstd/Cargo.toml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/libstd/Cargo.toml b/src/libstd/Cargo.toml
index 0d04b7a274037..173bcea0846a0 100644
--- a/src/libstd/Cargo.toml
+++ b/src/libstd/Cargo.toml
@@ -24,7 +24,6 @@ compiler_builtins = { version = "0.1.16" }
 profiler_builtins = { path = "../libprofiler_builtins", optional = true }
 unwind = { path = "../libunwind" }
 hashbrown = { version = "0.5.0", features = ['rustc-dep-of-std'] }
-wasi = { version = "0.7.0", features = ['rustc-dep-of-std', 'alloc'] }
 
 [dependencies.backtrace]
 version = "0.3.35"
@@ -57,6 +56,9 @@ dlmalloc = { version = "0.1", features = ['rustc-dep-of-std'] }
 [target.x86_64-fortanix-unknown-sgx.dependencies]
 fortanix-sgx-abi = { version = "0.3.2", features = ['rustc-dep-of-std'] }
 
+[target.wasm32-wasi.dependencies]
+wasi = { version = "0.7.0", features = ['rustc-dep-of-std', 'alloc'] }
+
 [build-dependencies]
 cc = "1.0"