Auto merge of #26159 - alexcrichton:tweak-process-lowering-raising, r=brson

* Slate these features to be stable in 1.2 instead of 1.1 (not being backported)
* Have the `FromRawFd` implementations follow the contract of the `FromRawFd`
  trait by taking ownership of the primitive specified.
* Refactor the implementations slightly to remove the `unreachable!` blocks as
  well as separating the stdio representation of `std::process` from
  `std::sys::process`.

cc #25494 

1 files changed, 8 insertions, 23 deletions

diff --git a/src/libstd/sys/windows/ext/process.rs b/src/libstd/sys/windows/ext/process.rs
index 0fd43a450f3..6f59be2687a 100644
--- a/src/libstd/sys/windows/ext/process.rs
+++ b/src/libstd/sys/windows/ext/process.rs
@@ -10,58 +10,43 @@
 
 //! Extensions to `std::process` for Windows.
 
-#![stable(feature = "from_raw_os", since = "1.1.0")]
+#![stable(feature = "process_extensions", since = "1.2.0")]
 
 use os::windows::io::{FromRawHandle, RawHandle, AsRawHandle};
 use process;
 use sys;
 use sys_common::{AsInner, FromInner};
 
-#[stable(feature = "from_raw_os", since = "1.1.0")]
+#[stable(feature = "process_extensions", since = "1.2.0")]
 impl FromRawHandle for process::Stdio {
-    /// Creates a new instance of `Stdio` from the raw underlying handle.
-    ///
-    /// When this `Stdio` is used as an I/O handle for a child process the given
-    /// handle will be duplicated via `DuplicateHandle` to ensure that the
-    /// handle has the correct permissions to cross the process boundary.
-    ///
-    /// Note that this function **does not** take ownership of the handle
-    /// provided and it will **not** be closed when `Stdio` goes out of scope.
-    /// As a result this method is unsafe because due to the lack of knowledge
-    /// about the lifetime of the provided handle, this could cause another I/O
-    /// primitive's ownership property of its handle to be violated.
-    ///
-    /// Also note that this handle may be used multiple times to spawn
-    /// processes. For example the `Command::spawn` function could be called
-    /// more than once to spawn more than one process sharing this handle.
     unsafe fn from_raw_handle(handle: RawHandle) -> process::Stdio {
-        let handle = sys::handle::RawHandle::new(handle as *mut _);
-        process::Stdio::from_inner(sys::process::Stdio::Handle(handle))
+        let handle = sys::handle::Handle::new(handle as *mut _);
+        process::Stdio::from_inner(handle)
     }
 }
 
-#[stable(feature = "from_raw_os", since = "1.1.0")]
+#[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawHandle for process::Child {
     fn as_raw_handle(&self) -> RawHandle {
         self.as_inner().handle().raw() as *mut _
     }
 }
 
-#[stable(feature = "from_raw_os", since = "1.1.0")]
+#[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawHandle for process::ChildStdin {
     fn as_raw_handle(&self) -> RawHandle {
         self.as_inner().handle().raw() as *mut _
     }
 }
 
-#[stable(feature = "from_raw_os", since = "1.1.0")]
+#[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawHandle for process::ChildStdout {
     fn as_raw_handle(&self) -> RawHandle {
         self.as_inner().handle().raw() as *mut _
     }
 }
 
-#[stable(feature = "from_raw_os", since = "1.1.0")]
+#[stable(feature = "process_extensions", since = "1.2.0")]
 impl AsRawHandle for process::ChildStderr {
     fn as_raw_handle(&self) -> RawHandle {
         self.as_inner().handle().raw() as *mut _