std: Implement stdio for `std::io`

This is an implementation of RFC 899 and adds stdio functionality to the new
`std::io` module. Details of the API can be found on the RFC, but from a high
level:

* `io::{stdin, stdout, stderr}` constructors are now available. There are also
  `*_raw` variants for unbuffered and unlocked access.
* All handles are globally shared (excluding raw variants).
* The stderr handle is no longer buffered.
* All handles can be explicitly locked (excluding the raw variants).

The `print!` and `println!` machinery has not yet been hooked up to these
streams just yet. The `std::fmt::output` module has also not yet been
implemented as part of this commit.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index 2d1a5e10bd6..8ed7302b665 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -48,6 +48,11 @@ pub const WSAESHUTDOWN: libc::c_int = 10058;
 pub const ERROR_NO_MORE_FILES: libc::DWORD = 18;
 pub const TOKEN_READ: libc::DWORD = 0x20008;
 
+// Note that these are not actually HANDLEs, just values to pass to GetStdHandle
+pub const STD_INPUT_HANDLE: libc::DWORD = -10;
+pub const STD_OUTPUT_HANDLE: libc::DWORD = -11;
+pub const STD_ERROR_HANDLE: libc::DWORD = -12;
+
 #[repr(C)]
 #[cfg(target_arch = "x86")]
 pub struct WSADATA {
@@ -427,6 +432,7 @@ extern "system" {
                             DesiredAccess: libc::DWORD,
                             TokenHandle: *mut libc::HANDLE) -> libc::BOOL;
     pub fn GetCurrentProcess() -> libc::HANDLE;
+    pub fn GetStdHandle(which: libc::DWORD) -> libc::HANDLE;
 }
 
 #[link(name = "userenv")]