Add std::process

Per [RFC 579](https://github.com/rust-lang/rfcs/pull/579), this commit
adds a new `std::process` module. This module is largely based on the
existing `std::old_io::process` module, but refactors the API to use
`OsStr` and other new standards set out by IO reform.

The existing module is not yet deprecated, to allow for the new API to
get a bit of testing before a mass migration to it.

5 files changed, 604 insertions, 18 deletions

diff --git a/src/libstd/sys/windows/fs2.rs b/src/libstd/sys/windows/fs2.rs
index 74bb509789b..8abcd90efe8 100644
--- a/src/libstd/sys/windows/fs2.rs
+++ b/src/libstd/sys/windows/fs2.rs
@@ -225,27 +225,11 @@ impl File {
     }
 
     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
-        let mut read = 0;
-        try!(cvt(unsafe {
-            libc::ReadFile(self.handle.raw(),
-                           buf.as_ptr() as libc::LPVOID,
-                           buf.len() as libc::DWORD,
-                           &mut read,
-                           ptr::null_mut())
-        }));
-        Ok(read as usize)
+        self.handle.read(buf)
     }
 
     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
-        let mut amt = 0;
-        try!(cvt(unsafe {
-            libc::WriteFile(self.handle.raw(),
-                            buf.as_ptr() as libc::LPVOID,
-                            buf.len() as libc::DWORD,
-                            &mut amt,
-                            ptr::null_mut())
-        }));
-        Ok(amt as usize)
+        self.handle.write(buf)
     }
 
     pub fn flush(&self) -> io::Result<()> { Ok(()) }
diff --git a/src/libstd/sys/windows/handle.rs b/src/libstd/sys/windows/handle.rs
index 52aa5fb036a..99de659be41 100644
--- a/src/libstd/sys/windows/handle.rs
+++ b/src/libstd/sys/windows/handle.rs
@@ -11,6 +11,10 @@
 use prelude::v1::*;
 
 use libc::{self, HANDLE};
+use io;
+use io::ErrorKind;
+use ptr;
+use sys::cvt;
 
 pub struct Handle(HANDLE);
 
@@ -21,7 +25,16 @@ impl Handle {
     pub fn new(handle: HANDLE) -> Handle {
         Handle(handle)
     }
+
     pub fn raw(&self) -> HANDLE { self.0 }
+
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
+        read(self.0, buf)
+    }
+
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
+        write(self.0, buf)
+    }
 }
 
 impl Drop for Handle {
@@ -30,3 +43,34 @@ impl Drop for Handle {
     }
 }
 
+
+pub fn read(h: HANDLE, buf: &mut [u8]) -> io::Result<usize> {
+    let mut read = 0;
+    let res = cvt(unsafe {
+        libc::ReadFile(h, buf.as_ptr() as libc::LPVOID,
+                       buf.len() as libc::DWORD, &mut read,
+                       ptr::null_mut())
+    });
+
+    match res {
+        Ok(_) => Ok(read as usize),
+
+        // The special treatment of BrokenPipe is to deal with Windows
+        // pipe semantics, which yields this error when *reading* from
+        // a pipe after the other end has closed; we interpret that as
+        // EOF on the pipe.
+        Err(ref e) if e.kind() == ErrorKind::BrokenPipe => Ok(0),
+
+        Err(e) => Err(e)
+    }
+}
+
+pub fn write(h: HANDLE, buf: &[u8]) -> io::Result<usize> {
+    let mut amt = 0;
+    try!(cvt(unsafe {
+        libc::WriteFile(h, buf.as_ptr() as libc::LPVOID,
+                        buf.len() as libc::DWORD, &mut amt,
+                        ptr::null_mut())
+    }));
+    Ok(amt as usize)
+}
diff --git a/src/libstd/sys/windows/mod.rs b/src/libstd/sys/windows/mod.rs
index 0fa9aaf4323..4d6d033deee 100644
--- a/src/libstd/sys/windows/mod.rs
+++ b/src/libstd/sys/windows/mod.rs
@@ -47,7 +47,9 @@ pub mod net;
 pub mod os;
 pub mod os_str;
 pub mod pipe;
+pub mod pipe2;
 pub mod process;
+pub mod process2;
 pub mod rwlock;
 pub mod stack_overflow;
 pub mod sync;
diff --git a/src/libstd/sys/windows/pipe2.rs b/src/libstd/sys/windows/pipe2.rs
new file mode 100644
index 00000000000..229481e3d57
--- /dev/null
+++ b/src/libstd/sys/windows/pipe2.rs
@@ -0,0 +1,77 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use prelude::v1::*;
+
+use sys::handle;
+use io;
+use libc::{self, c_int, HANDLE};
+
+////////////////////////////////////////////////////////////////////////////////
+// Anonymous pipes
+////////////////////////////////////////////////////////////////////////////////
+
+pub struct AnonPipe {
+    fd: c_int
+}
+
+pub unsafe fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> {
+    // Windows pipes work subtly differently than unix pipes, and their
+    // inheritance has to be handled in a different way that I do not
+    // fully understand. Here we explicitly make the pipe non-inheritable,
+    // which means to pass it to a subprocess they need to be duplicated
+    // first, as in std::run.
+    let mut fds = [0; 2];
+    match libc::pipe(fds.as_mut_ptr(), 1024 as ::libc::c_uint,
+    (libc::O_BINARY | libc::O_NOINHERIT) as c_int) {
+        0 => {
+            assert!(fds[0] != -1 && fds[0] != 0);
+            assert!(fds[1] != -1 && fds[1] != 0);
+
+            Ok((AnonPipe::from_fd(fds[0]), AnonPipe::from_fd(fds[1])))
+        }
+        _ => Err(io::Error::last_os_error()),
+    }
+}
+
+impl AnonPipe {
+    pub fn from_fd(fd: libc::c_int) -> AnonPipe {
+        AnonPipe { fd: fd }
+    }
+
+    pub fn raw(&self) -> HANDLE {
+        unsafe { libc::get_osfhandle(self.fd) as libc::HANDLE }
+    }
+
+    pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
+        handle::read(self.raw(), buf)
+    }
+
+    pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
+        handle::write(self.raw(), buf)
+    }
+}
+
+impl Drop for AnonPipe {
+    fn drop(&mut self) {
+        // closing stdio file handles makes no sense, so never do it. Also, note
+        // that errors are ignored when closing a file descriptor. The reason
+        // for this is that if an error occurs we don't actually know if the
+        // file descriptor was closed or not, and if we retried (for something
+        // like EINTR), we might close another valid file descriptor (opened
+        // after we closed ours.
+        if self.fd > libc::STDERR_FILENO {
+            let n = unsafe { libc::close(self.fd) };
+            if n != 0 {
+                println!("error {} when closing file descriptor {}", n, self.fd);
+            }
+        }
+    }
+}
diff --git a/src/libstd/sys/windows/process2.rs b/src/libstd/sys/windows/process2.rs
new file mode 100644
index 00000000000..19e38196d19
--- /dev/null
+++ b/src/libstd/sys/windows/process2.rs
@@ -0,0 +1,479 @@
+// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use prelude::v1::*;
+
+use ascii::*;
+use collections::HashMap;
+use collections;
+use env;
+use ffi::{OsString, OsStr};
+use fmt;
+use io::{self, Error};
+use libc::{self, c_void};
+use old_io::fs;
+use old_path;
+use os::windows::OsStrExt;
+use ptr;
+use sync::{StaticMutex, MUTEX_INIT};
+use sys::pipe2::AnonPipe;
+use sys::{self, cvt};
+use sys::handle::Handle;
+use sys_common::{AsInner, FromInner};
+
+////////////////////////////////////////////////////////////////////////////////
+// Command
+////////////////////////////////////////////////////////////////////////////////
+
+fn mk_key(s: &OsStr) -> OsString {
+    FromInner::from_inner(sys::os_str::Buf {
+        inner: s.as_inner().inner.to_ascii_uppercase()
+    })
+}
+
+#[derive(Clone)]
+pub struct Command {
+    pub program: OsString,
+    pub args: Vec<OsString>,
+    pub env: Option<HashMap<OsString, OsString>>,
+    pub cwd: Option<OsString>,
+    pub detach: bool, // not currently exposed in std::process
+}
+
+impl Command {
+    pub fn new(program: &OsStr) -> Command {
+        Command {
+            program: program.to_os_string(),
+            args: Vec::new(),
+            env: None,
+            cwd: None,
+            detach: false,
+        }
+    }
+
+    pub fn arg(&mut self, arg: &OsStr) {
+        self.args.push(arg.to_os_string())
+    }
+    pub fn args<'a, I: Iterator<Item = &'a OsStr>>(&mut self, args: I) {
+        self.args.extend(args.map(OsStr::to_os_string))
+    }
+    fn init_env_map(&mut self){
+        if self.env.is_none() {
+            self.env = Some(env::vars_os().map(|(key, val)| {
+                (mk_key(&key), val)
+            }).collect());
+        }
+    }
+    pub fn env(&mut self, key: &OsStr, val: &OsStr) {
+        self.init_env_map();
+        self.env.as_mut().unwrap().insert(mk_key(key), val.to_os_string());
+    }
+    pub fn env_remove(&mut self, key: &OsStr) {
+        self.init_env_map();
+        self.env.as_mut().unwrap().remove(&mk_key(key));
+    }
+    pub fn env_clear(&mut self) {
+        self.env = Some(HashMap::new())
+    }
+    pub fn cwd(&mut self, dir: &OsStr) {
+        self.cwd = Some(dir.to_os_string())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Processes
+////////////////////////////////////////////////////////////////////////////////
+
+// `CreateProcess` is racy!
+// http://support.microsoft.com/kb/315939
+static CREATE_PROCESS_LOCK: StaticMutex = MUTEX_INIT;
+
+/// A value representing a child process.
+///
+/// The lifetime of this value is linked to the lifetime of the actual
+/// process - the Process destructor calls self.finish() which waits
+/// for the process to terminate.
+pub struct Process {
+    /// A HANDLE to the process, which will prevent the pid being
+    /// re-used until the handle is closed.
+    handle: Handle,
+}
+
+impl Process {
+    #[allow(deprecated)]
+    pub fn spawn(cfg: &Command,
+                 in_fd: Option<AnonPipe>, out_fd: Option<AnonPipe>, err_fd: Option<AnonPipe>)
+                 -> io::Result<Process>
+    {
+        use libc::types::os::arch::extra::{DWORD, HANDLE, STARTUPINFO};
+        use libc::consts::os::extra::{
+            TRUE, FALSE,
+            STARTF_USESTDHANDLES,
+            INVALID_HANDLE_VALUE,
+            DUPLICATE_SAME_ACCESS
+        };
+        use libc::funcs::extra::kernel32::{
+            GetCurrentProcess,
+            DuplicateHandle,
+            CloseHandle,
+            CreateProcessW
+        };
+
+        use env::split_paths;
+        use mem;
+        use iter::IteratorExt;
+        use str::StrExt;
+
+        // To have the spawning semantics of unix/windows stay the same, we need to
+        // read the *child's* PATH if one is provided. See #15149 for more details.
+        let program = cfg.env.as_ref().and_then(|env| {
+            for (key, v) in env {
+                if OsStr::from_str("PATH") != &**key { continue }
+
+                // Split the value and test each path to see if the
+                // program exists.
+                for path in split_paths(&v) {
+                    let path = path.join(cfg.program.to_str().unwrap())
+                                   .with_extension(env::consts::EXE_EXTENSION);
+                    // FIXME: update with new fs module once it lands
+                    if fs::stat(&old_path::Path::new(&path)).is_ok() {
+                        return Some(OsString::from_str(path.as_str().unwrap()))
+                    }
+                }
+                break
+            }
+            None
+        });
+
+        unsafe {
+            let mut si = zeroed_startupinfo();
+            si.cb = mem::size_of::<STARTUPINFO>() as DWORD;
+            si.dwFlags = STARTF_USESTDHANDLES;
+
+            let cur_proc = GetCurrentProcess();
+
+            // Similarly to unix, we don't actually leave holes for the stdio file
+            // descriptors, but rather open up /dev/null equivalents. These
+            // equivalents are drawn from libuv's windows process spawning.
+            let set_fd = |&: fd: &Option<AnonPipe>, slot: &mut HANDLE,
+                          is_stdin: bool| {
+                match *fd {
+                    None => {
+                        let access = if is_stdin {
+                            libc::FILE_GENERIC_READ
+                        } else {
+                            libc::FILE_GENERIC_WRITE | libc::FILE_READ_ATTRIBUTES
+                        };
+                        let size = mem::size_of::<libc::SECURITY_ATTRIBUTES>();
+                        let mut sa = libc::SECURITY_ATTRIBUTES {
+                            nLength: size as libc::DWORD,
+                            lpSecurityDescriptor: ptr::null_mut(),
+                            bInheritHandle: 1,
+                        };
+                        let mut filename: Vec<u16> = "NUL".utf16_units().collect();
+                        filename.push(0);
+                        *slot = libc::CreateFileW(filename.as_ptr(),
+                                                  access,
+                                                  libc::FILE_SHARE_READ |
+                                                      libc::FILE_SHARE_WRITE,
+                                                  &mut sa,
+                                                  libc::OPEN_EXISTING,
+                                                  0,
+                                                  ptr::null_mut());
+                        if *slot == INVALID_HANDLE_VALUE {
+                            return Err(Error::last_os_error())
+                        }
+                    }
+                    Some(ref pipe) => {
+                        let orig = pipe.raw();
+                        if orig == INVALID_HANDLE_VALUE {
+                            return Err(Error::last_os_error())
+                        }
+                        if DuplicateHandle(cur_proc, orig, cur_proc, slot,
+                                           0, TRUE, DUPLICATE_SAME_ACCESS) == FALSE {
+                            return Err(Error::last_os_error())
+                        }
+                    }
+                }
+                Ok(())
+            };
+
+            try!(set_fd(&in_fd, &mut si.hStdInput, true));
+            try!(set_fd(&out_fd, &mut si.hStdOutput, false));
+            try!(set_fd(&err_fd, &mut si.hStdError, false));
+
+            let mut cmd_str = make_command_line(program.as_ref().unwrap_or(&cfg.program),
+                                            &cfg.args);
+            cmd_str.push(0); // add null terminator
+
+            let mut pi = zeroed_process_information();
+            let mut create_err = None;
+
+            // stolen from the libuv code.
+            let mut flags = libc::CREATE_UNICODE_ENVIRONMENT;
+            if cfg.detach {
+                flags |= libc::DETACHED_PROCESS | libc::CREATE_NEW_PROCESS_GROUP;
+            }
+
+            with_envp(cfg.env.as_ref(), |envp| {
+                with_dirp(cfg.cwd.as_ref(), |dirp| {
+                    let _lock = CREATE_PROCESS_LOCK.lock().unwrap();
+                    let created = CreateProcessW(ptr::null(),
+                                                 cmd_str.as_mut_ptr(),
+                                                 ptr::null_mut(),
+                                                 ptr::null_mut(),
+                                                 TRUE,
+                                                 flags, envp, dirp,
+                                                 &mut si, &mut pi);
+                    if created == FALSE {
+                        create_err = Some(Error::last_os_error());
+                    }
+                })
+            });
+
+            assert!(CloseHandle(si.hStdInput) != 0);
+            assert!(CloseHandle(si.hStdOutput) != 0);
+            assert!(CloseHandle(si.hStdError) != 0);
+
+            match create_err {
+                Some(err) => return Err(err),
+                None => {}
+            }
+
+            // We close the thread handle because we don't care about keeping the
+            // thread id valid, and we aren't keeping the thread handle around to be
+            // able to close it later. We don't close the process handle however
+            // because std::we want the process id to stay valid at least until the
+            // calling code closes the process handle.
+            assert!(CloseHandle(pi.hThread) != 0);
+
+            Ok(Process {
+                handle: Handle::new(pi.hProcess)
+            })
+        }
+    }
+
+    pub unsafe fn kill(&self) -> io::Result<()> {
+        try!(cvt(libc::TerminateProcess(self.handle.raw(), 1)));
+        Ok(())
+    }
+
+    pub fn wait(&self) -> io::Result<ExitStatus> {
+        use libc::consts::os::extra::{
+            FALSE,
+            STILL_ACTIVE,
+            INFINITE,
+            WAIT_OBJECT_0,
+        };
+        use libc::funcs::extra::kernel32::{
+            GetExitCodeProcess,
+            WaitForSingleObject,
+        };
+
+        unsafe {
+            loop {
+                let mut status = 0;
+                if GetExitCodeProcess(self.handle.raw(), &mut status) == FALSE {
+                    let err = Err(Error::last_os_error());
+                    return err;
+                }
+                if status != STILL_ACTIVE {
+                    return Ok(ExitStatus(status as i32));
+                }
+                match WaitForSingleObject(self.handle.raw(), INFINITE) {
+                    WAIT_OBJECT_0 => {}
+                    _ => {
+                        let err = Err(Error::last_os_error());
+                        return err
+                    }
+                }
+            }
+        }
+    }
+}
+
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+pub struct ExitStatus(i32);
+
+impl ExitStatus {
+    pub fn success(&self) -> bool {
+        self.0 == 0
+    }
+    pub fn code(&self) -> Option<i32> {
+        Some(self.0)
+    }
+}
+
+impl fmt::Display for ExitStatus {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "exit code: {}", self.0)
+    }
+}
+
+fn zeroed_startupinfo() -> libc::types::os::arch::extra::STARTUPINFO {
+    libc::types::os::arch::extra::STARTUPINFO {
+        cb: 0,
+        lpReserved: ptr::null_mut(),
+        lpDesktop: ptr::null_mut(),
+        lpTitle: ptr::null_mut(),
+        dwX: 0,
+        dwY: 0,
+        dwXSize: 0,
+        dwYSize: 0,
+        dwXCountChars: 0,
+        dwYCountCharts: 0,
+        dwFillAttribute: 0,
+        dwFlags: 0,
+        wShowWindow: 0,
+        cbReserved2: 0,
+        lpReserved2: ptr::null_mut(),
+        hStdInput: libc::INVALID_HANDLE_VALUE,
+        hStdOutput: libc::INVALID_HANDLE_VALUE,
+        hStdError: libc::INVALID_HANDLE_VALUE,
+    }
+}
+
+fn zeroed_process_information() -> libc::types::os::arch::extra::PROCESS_INFORMATION {
+    libc::types::os::arch::extra::PROCESS_INFORMATION {
+        hProcess: ptr::null_mut(),
+        hThread: ptr::null_mut(),
+        dwProcessId: 0,
+        dwThreadId: 0
+    }
+}
+
+// Produces a wide string *without terminating null*
+fn make_command_line(prog: &OsStr, args: &[OsString]) -> Vec<u16> {
+    let mut cmd: Vec<u16> = Vec::new();
+    append_arg(&mut cmd, prog);
+    for arg in args {
+        cmd.push(' ' as u16);
+        append_arg(&mut cmd, arg);
+    }
+    return cmd;
+
+    fn append_arg(cmd: &mut Vec<u16>, arg: &OsStr) {
+        // If an argument has 0 characters then we need to quote it to ensure
+        // that it actually gets passed through on the command line or otherwise
+        // it will be dropped entirely when parsed on the other end.
+        let arg_bytes = &arg.as_inner().inner.as_inner();
+        let quote = arg_bytes.iter().any(|c| *c == b' ' || *c == b'\t')
+            || arg_bytes.len() == 0;
+        if quote {
+            cmd.push('"' as u16);
+        }
+
+        let mut iter = arg.encode_wide();
+        while let Some(x) = iter.next() {
+            if x == '"' as u16 {
+                // escape quotes
+                cmd.push('\\' as u16);
+                cmd.push('"' as u16);
+            } else if x == '\\' as u16 {
+                // is this a run of backslashes followed by a " ?
+                if iter.clone().skip_while(|y| *y == '\\' as u16).next() == Some('"' as u16) {
+                    // Double it ... NOTE: this behavior is being
+                    // preserved as it's been part of Rust for a long
+                    // time, but no one seems to know exactly why this
+                    // is the right thing to do.
+                    cmd.push('\\' as u16);
+                    cmd.push('\\' as u16);
+                } else {
+                    // Push it through unescaped
+                    cmd.push('\\' as u16);
+                }
+            } else {
+                cmd.push(x)
+            }
+        }
+
+        if quote {
+            cmd.push('"' as u16);
+        }
+    }
+}
+
+fn with_envp<F, T>(env: Option<&collections::HashMap<OsString, OsString>>, cb: F) -> T
+    where F: FnOnce(*mut c_void) -> T,
+{
+    // On Windows we pass an "environment block" which is not a char**, but
+    // rather a concatenation of null-terminated k=v\0 sequences, with a final
+    // \0 to terminate.
+    match env {
+        Some(env) => {
+            let mut blk = Vec::new();
+
+            for pair in env {
+                blk.extend(pair.0.encode_wide());
+                blk.push('=' as u16);
+                blk.extend(pair.1.encode_wide());
+                blk.push(0);
+            }
+            blk.push(0);
+            cb(blk.as_mut_ptr() as *mut c_void)
+        }
+        _ => cb(ptr::null_mut())
+    }
+}
+
+fn with_dirp<T, F>(d: Option<&OsString>, cb: F) -> T where
+    F: FnOnce(*const u16) -> T,
+{
+    match d {
+      Some(dir) => {
+          let mut dir_str: Vec<u16> = dir.encode_wide().collect();
+          dir_str.push(0);
+          cb(dir_str.as_ptr())
+      },
+      None => cb(ptr::null())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use prelude::v1::*;
+    use str;
+    use ffi::{OsStr, OsString};
+    use super::make_command_line;
+
+    #[test]
+    fn test_make_command_line() {
+        fn test_wrapper(prog: &str, args: &[&str]) -> String {
+            String::from_utf16(
+                &make_command_line(OsStr::from_str(prog),
+                                   args.iter()
+                                       .map(|a| OsString::from_str(a))
+                                       .collect::<Vec<OsString>>()
+                                       .as_slice())).unwrap()
+        }
+
+        assert_eq!(
+            test_wrapper("prog", &["aaa", "bbb", "ccc"]),
+            "prog aaa bbb ccc"
+        );
+
+        assert_eq!(
+            test_wrapper("C:\\Program Files\\blah\\blah.exe", &["aaa"]),
+            "\"C:\\Program Files\\blah\\blah.exe\" aaa"
+        );
+        assert_eq!(
+            test_wrapper("C:\\Program Files\\test", &["aa\"bb"]),
+            "\"C:\\Program Files\\test\" aa\\\"bb"
+        );
+        assert_eq!(
+            test_wrapper("echo", &["a b c"]),
+            "echo \"a b c\""
+        );
+        assert_eq!(
+            test_wrapper("\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}", &[]),
+            "\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}"
+        );
+    }
+}