Be more specific about winapi features

[Darksonn]

Our dependency on winapi is listed in the following way:

[target.'cfg(windows)'.dependencies.winapi]
version = "0.3.8"
default-features = false
features = ["std", "winsock2", "mswsock", "handleapi", "ws2ipdef", "ws2tcpip"]
optional = true

Additionally, the various features of Tokio that require something from winapi can enable additional winapi features, e.g.:

net = [
  "libc",
  "mio/os-poll",
  "mio/os-ext",
  "mio/net",
  "socket2",
  "winapi/namedpipeapi",
]

However, the features that are listed in the [target.'cfg(windows)'.dependencies.winapi] section are also specific to various other features of Tokio, and hence enabled more often than necessary. We would like to be more specific about which features we need, and only enable each feature when we need it by moving them to be listed on other dependencies like "winapi/namedpipeapi".

[notgull]

I disabled all of the winapi features that are on by default and, at least on my build, it doesn't seem to raise any issues. Might be on my end, let me run the CI just to be sure.

[Darksonn]

The features were added like this to fix #4662, so if you remove them, that issue should come back. (Of course, only on windows builds.)

[gftea]

try to work on this, I am new to rust, and can you help below question @Darksonn

in net/windows/named_pipe.rs

in below codes, as I understand crate:io refer to io module in src folder, but I cannot find os module in it, so which module crate::os refer to?

use crate::io::{AsyncRead, AsyncWrite, Interest, PollEvented, ReadBuf, Ready};
use crate::os::windows::io::{AsRawHandle, FromRawHandle, RawHandle};

[Darksonn]

The crate::os module is a re-export of std::os.

It exists because Tokio replaces it with something else when building documentation to show windows stuff in docs built on Linux.

[gftea]

@Darksonn , tests pass with above change in PR, I am unclear why we do not have error regarding unresolved import even though in named_pipe.rs, there are below import

    pub(super) use crate::os::windows::ffi::OsStrExt;
    pub(super) use crate::winapi::shared::minwindef::{DWORD, FALSE};
    pub(super) use crate::winapi::um::fileapi;
    pub(super) use crate::winapi::um::handleapi;
    pub(super) use crate::winapi::um::namedpipeapi;
    pub(super) use crate::winapi::um::winbase;
    pub(super) use crate::winapi::um::winnt;

[gftea]

This issue can be closed because the PR merged? @Darksonn

[Darksonn]

Ah, thanks. I didn't notice that the PR wasn't set up to auto-close this issue when merged.