Update for latest nightly 2018-06-09 (#70)

* Update for latest nightly 2018-06-09
* We now have a proper horizon os and sys modules in libstd

1 files changed, 543 insertions, 0 deletions

diff --git a/ctr-std/src/sys/redox/process.rs b/ctr-std/src/sys/redox/process.rs
new file mode 100644
index 0000000..d0b94e1
--- /dev/null
+++ b/ctr-std/src/sys/redox/process.rs
@@ -0,0 +1,543 @@
+// Copyright 2016 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 env::{split_paths};
+use ffi::OsStr;
+use os::unix::ffi::OsStrExt;
+use fmt;
+use io::{self, Error, ErrorKind};
+use libc::{EXIT_SUCCESS, EXIT_FAILURE};
+use path::{Path, PathBuf};
+use sys::fd::FileDesc;
+use sys::fs::{File, OpenOptions};
+use sys::pipe::{self, AnonPipe};
+use sys::{cvt, syscall};
+use sys_common::process::{CommandEnv, DefaultEnvKey};
+
+////////////////////////////////////////////////////////////////////////////////
+// Command
+////////////////////////////////////////////////////////////////////////////////
+
+pub struct Command {
+    // Currently we try hard to ensure that the call to `.exec()` doesn't
+    // actually allocate any memory. While many platforms try to ensure that
+    // memory allocation works after a fork in a multithreaded process, it's
+    // been observed to be buggy and somewhat unreliable, so we do our best to
+    // just not do it at all!
+    //
+    // Along those lines, the `argv` and `envp` raw pointers here are exactly
+    // what's gonna get passed to `execvp`. The `argv` array starts with the
+    // `program` and ends with a NULL, and the `envp` pointer, if present, is
+    // also null-terminated.
+    //
+    // Right now we don't support removing arguments, so there's no much fancy
+    // support there, but we support adding and removing environment variables,
+    // so a side table is used to track where in the `envp` array each key is
+    // located. Whenever we add a key we update it in place if it's already
+    // present, and whenever we remove a key we update the locations of all
+    // other keys.
+    program: String,
+    args: Vec<String>,
+    env: CommandEnv<DefaultEnvKey>,
+
+    cwd: Option<String>,
+    uid: Option<u32>,
+    gid: Option<u32>,
+    saw_nul: bool,
+    closures: Vec<Box<FnMut() -> io::Result<()> + Send + Sync>>,
+    stdin: Option<Stdio>,
+    stdout: Option<Stdio>,
+    stderr: Option<Stdio>,
+}
+
+// passed back to std::process with the pipes connected to the child, if any
+// were requested
+pub struct StdioPipes {
+    pub stdin: Option<AnonPipe>,
+    pub stdout: Option<AnonPipe>,
+    pub stderr: Option<AnonPipe>,
+}
+
+// passed to do_exec() with configuration of what the child stdio should look
+// like
+struct ChildPipes {
+    stdin: ChildStdio,
+    stdout: ChildStdio,
+    stderr: ChildStdio,
+}
+
+enum ChildStdio {
+    Inherit,
+    Explicit(usize),
+    Owned(FileDesc),
+}
+
+pub enum Stdio {
+    Inherit,
+    Null,
+    MakePipe,
+    Fd(FileDesc),
+}
+
+impl Command {
+    pub fn new(program: &OsStr) -> Command {
+        Command {
+            program: program.to_str().unwrap().to_owned(),
+            args: Vec::new(),
+            env: Default::default(),
+            cwd: None,
+            uid: None,
+            gid: None,
+            saw_nul: false,
+            closures: Vec::new(),
+            stdin: None,
+            stdout: None,
+            stderr: None,
+        }
+    }
+
+    pub fn arg(&mut self, arg: &OsStr) {
+        self.args.push(arg.to_str().unwrap().to_owned());
+    }
+
+    pub fn env_mut(&mut self) -> &mut CommandEnv<DefaultEnvKey> {
+        &mut self.env
+    }
+
+    pub fn cwd(&mut self, dir: &OsStr) {
+        self.cwd = Some(dir.to_str().unwrap().to_owned());
+    }
+    pub fn uid(&mut self, id: u32) {
+        self.uid = Some(id);
+    }
+    pub fn gid(&mut self, id: u32) {
+        self.gid = Some(id);
+    }
+
+    pub fn before_exec(&mut self,
+                       f: Box<FnMut() -> io::Result<()> + Send + Sync>) {
+        self.closures.push(f);
+    }
+
+    pub fn stdin(&mut self, stdin: Stdio) {
+        self.stdin = Some(stdin);
+    }
+    pub fn stdout(&mut self, stdout: Stdio) {
+        self.stdout = Some(stdout);
+    }
+    pub fn stderr(&mut self, stderr: Stdio) {
+        self.stderr = Some(stderr);
+    }
+
+    pub fn spawn(&mut self, default: Stdio, needs_stdin: bool)
+                 -> io::Result<(Process, StdioPipes)> {
+         const CLOEXEC_MSG_FOOTER: &'static [u8] = b"NOEX";
+
+         if self.saw_nul {
+             return Err(io::Error::new(ErrorKind::InvalidInput,
+                                       "nul byte found in provided data"));
+         }
+
+         let (ours, theirs) = self.setup_io(default, needs_stdin)?;
+         let (input, output) = pipe::anon_pipe()?;
+
+         let pid = unsafe {
+             match cvt(syscall::clone(0))? {
+                 0 => {
+                     drop(input);
+                     let err = self.do_exec(theirs);
+                     let errno = err.raw_os_error().unwrap_or(syscall::EINVAL) as u32;
+                     let bytes = [
+                         (errno >> 24) as u8,
+                         (errno >> 16) as u8,
+                         (errno >>  8) as u8,
+                         (errno >>  0) as u8,
+                         CLOEXEC_MSG_FOOTER[0], CLOEXEC_MSG_FOOTER[1],
+                         CLOEXEC_MSG_FOOTER[2], CLOEXEC_MSG_FOOTER[3]
+                     ];
+                     // pipe I/O up to PIPE_BUF bytes should be atomic, and then
+                     // we want to be sure we *don't* run at_exit destructors as
+                     // we're being torn down regardless
+                     assert!(output.write(&bytes).is_ok());
+                     let _ = syscall::exit(1);
+                     panic!("failed to exit");
+                 }
+                 n => n,
+             }
+         };
+
+         let mut p = Process { pid: pid, status: None };
+         drop(output);
+         let mut bytes = [0; 8];
+
+         // loop to handle EINTR
+         loop {
+             match input.read(&mut bytes) {
+                 Ok(0) => return Ok((p, ours)),
+                 Ok(8) => {
+                     assert!(combine(CLOEXEC_MSG_FOOTER) == combine(&bytes[4.. 8]),
+                             "Validation on the CLOEXEC pipe failed: {:?}", bytes);
+                     let errno = combine(&bytes[0.. 4]);
+                     assert!(p.wait().is_ok(),
+                             "wait() should either return Ok or panic");
+                     return Err(Error::from_raw_os_error(errno))
+                 }
+                 Err(ref e) if e.kind() == ErrorKind::Interrupted => {}
+                 Err(e) => {
+                     assert!(p.wait().is_ok(),
+                             "wait() should either return Ok or panic");
+                     panic!("the CLOEXEC pipe failed: {:?}", e)
+                 },
+                 Ok(..) => { // pipe I/O up to PIPE_BUF bytes should be atomic
+                     assert!(p.wait().is_ok(),
+                             "wait() should either return Ok or panic");
+                     panic!("short read on the CLOEXEC pipe")
+                 }
+             }
+         }
+
+         fn combine(arr: &[u8]) -> i32 {
+             let a = arr[0] as u32;
+             let b = arr[1] as u32;
+             let c = arr[2] as u32;
+             let d = arr[3] as u32;
+
+             ((a << 24) | (b << 16) | (c << 8) | (d << 0)) as i32
+         }
+    }
+
+    pub fn exec(&mut self, default: Stdio) -> io::Error {
+        if self.saw_nul {
+            return io::Error::new(ErrorKind::InvalidInput,
+                                  "nul byte found in provided data")
+        }
+
+        match self.setup_io(default, true) {
+            Ok((_, theirs)) => unsafe { self.do_exec(theirs) },
+            Err(e) => e,
+        }
+    }
+
+    // And at this point we've reached a special time in the life of the
+    // child. The child must now be considered hamstrung and unable to
+    // do anything other than syscalls really. Consider the following
+    // scenario:
+    //
+    //      1. Thread A of process 1 grabs the malloc() mutex
+    //      2. Thread B of process 1 forks(), creating thread C
+    //      3. Thread C of process 2 then attempts to malloc()
+    //      4. The memory of process 2 is the same as the memory of
+    //         process 1, so the mutex is locked.
+    //
+    // This situation looks a lot like deadlock, right? It turns out
+    // that this is what pthread_atfork() takes care of, which is
+    // presumably implemented across platforms. The first thing that
+    // threads to *before* forking is to do things like grab the malloc
+    // mutex, and then after the fork they unlock it.
+    //
+    // Despite this information, libnative's spawn has been witnessed to
+    // deadlock on both macOS and FreeBSD. I'm not entirely sure why, but
+    // all collected backtraces point at malloc/free traffic in the
+    // child spawned process.
+    //
+    // For this reason, the block of code below should contain 0
+    // invocations of either malloc of free (or their related friends).
+    //
+    // As an example of not having malloc/free traffic, we don't close
+    // this file descriptor by dropping the FileDesc (which contains an
+    // allocation). Instead we just close it manually. This will never
+    // have the drop glue anyway because this code never returns (the
+    // child will either exec() or invoke syscall::exit)
+    unsafe fn do_exec(&mut self, stdio: ChildPipes) -> io::Error {
+        macro_rules! t {
+            ($e:expr) => (match $e {
+                Ok(e) => e,
+                Err(e) => return e,
+            })
+        }
+
+        if let Some(fd) = stdio.stderr.fd() {
+            t!(cvt(syscall::dup2(fd, 2, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(2, syscall::F_GETFD, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(2, syscall::F_SETFD, flags)));
+        }
+        if let Some(fd) = stdio.stdout.fd() {
+            t!(cvt(syscall::dup2(fd, 1, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(1, syscall::F_GETFD, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(1, syscall::F_SETFD, flags)));
+        }
+        if let Some(fd) = stdio.stdin.fd() {
+            t!(cvt(syscall::dup2(fd, 0, &[])));
+            let mut flags = t!(cvt(syscall::fcntl(0, syscall::F_GETFD, 0)));
+            flags &= ! syscall::O_CLOEXEC;
+            t!(cvt(syscall::fcntl(0, syscall::F_SETFD, flags)));
+        }
+
+        if let Some(g) = self.gid {
+            t!(cvt(syscall::setregid(g as usize, g as usize)));
+        }
+        if let Some(u) = self.uid {
+            t!(cvt(syscall::setreuid(u as usize, u as usize)));
+        }
+        if let Some(ref cwd) = self.cwd {
+            t!(cvt(syscall::chdir(cwd)));
+        }
+
+        for callback in self.closures.iter_mut() {
+            t!(callback());
+        }
+
+        let mut args: Vec<[usize; 2]> = Vec::new();
+        args.push([self.program.as_ptr() as usize, self.program.len()]);
+        for arg in self.args.iter() {
+            args.push([arg.as_ptr() as usize, arg.len()]);
+        }
+
+        self.env.apply();
+
+        let program = if self.program.contains(':') || self.program.contains('/') {
+            Some(PathBuf::from(&self.program))
+        } else if let Ok(path_env) = ::env::var("PATH") {
+            let mut program = None;
+            for mut path in split_paths(&path_env) {
+                path.push(&self.program);
+                if path.exists() {
+                    program = Some(path);
+                    break;
+                }
+            }
+            program
+        } else {
+            None
+        };
+
+        if let Some(program) = program {
+            if let Err(err) = syscall::execve(program.as_os_str().as_bytes(), &args) {
+                io::Error::from_raw_os_error(err.errno as i32)
+            } else {
+                panic!("return from exec without err");
+            }
+        } else {
+            io::Error::from_raw_os_error(syscall::ENOENT)
+        }
+    }
+
+
+    fn setup_io(&self, default: Stdio, needs_stdin: bool)
+                -> io::Result<(StdioPipes, ChildPipes)> {
+        let null = Stdio::Null;
+        let default_stdin = if needs_stdin {&default} else {&null};
+        let stdin = self.stdin.as_ref().unwrap_or(default_stdin);
+        let stdout = self.stdout.as_ref().unwrap_or(&default);
+        let stderr = self.stderr.as_ref().unwrap_or(&default);
+        let (their_stdin, our_stdin) = stdin.to_child_stdio(true)?;
+        let (their_stdout, our_stdout) = stdout.to_child_stdio(false)?;
+        let (their_stderr, our_stderr) = stderr.to_child_stdio(false)?;
+        let ours = StdioPipes {
+            stdin: our_stdin,
+            stdout: our_stdout,
+            stderr: our_stderr,
+        };
+        let theirs = ChildPipes {
+            stdin: their_stdin,
+            stdout: their_stdout,
+            stderr: their_stderr,
+        };
+        Ok((ours, theirs))
+    }
+}
+
+impl Stdio {
+    fn to_child_stdio(&self, readable: bool)
+                      -> io::Result<(ChildStdio, Option<AnonPipe>)> {
+        match *self {
+            Stdio::Inherit => Ok((ChildStdio::Inherit, None)),
+
+            // Make sure that the source descriptors are not an stdio
+            // descriptor, otherwise the order which we set the child's
+            // descriptors may blow away a descriptor which we are hoping to
+            // save. For example, suppose we want the child's stderr to be the
+            // parent's stdout, and the child's stdout to be the parent's
+            // stderr. No matter which we dup first, the second will get
+            // overwritten prematurely.
+            Stdio::Fd(ref fd) => {
+                if fd.raw() <= 2 {
+                    Ok((ChildStdio::Owned(fd.duplicate()?), None))
+                } else {
+                    Ok((ChildStdio::Explicit(fd.raw()), None))
+                }
+            }
+
+            Stdio::MakePipe => {
+                let (reader, writer) = pipe::anon_pipe()?;
+                let (ours, theirs) = if readable {
+                    (writer, reader)
+                } else {
+                    (reader, writer)
+                };
+                Ok((ChildStdio::Owned(theirs.into_fd()), Some(ours)))
+            }
+
+            Stdio::Null => {
+                let mut opts = OpenOptions::new();
+                opts.read(readable);
+                opts.write(!readable);
+                let fd = File::open(Path::new("null:"), &opts)?;
+                Ok((ChildStdio::Owned(fd.into_fd()), None))
+            }
+        }
+    }
+}
+
+impl From<AnonPipe> for Stdio {
+    fn from(pipe: AnonPipe) -> Stdio {
+        Stdio::Fd(pipe.into_fd())
+    }
+}
+
+impl From<File> for Stdio {
+    fn from(file: File) -> Stdio {
+        Stdio::Fd(file.into_fd())
+    }
+}
+
+impl ChildStdio {
+    fn fd(&self) -> Option<usize> {
+        match *self {
+            ChildStdio::Inherit => None,
+            ChildStdio::Explicit(fd) => Some(fd),
+            ChildStdio::Owned(ref fd) => Some(fd.raw()),
+        }
+    }
+}
+
+impl fmt::Debug for Command {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{:?}", self.program)?;
+        for arg in &self.args {
+            write!(f, " {:?}", arg)?;
+        }
+        Ok(())
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Processes
+////////////////////////////////////////////////////////////////////////////////
+
+/// Unix exit statuses
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+pub struct ExitStatus(i32);
+
+impl ExitStatus {
+    fn exited(&self) -> bool {
+        self.0 & 0x7F == 0
+    }
+
+    pub fn success(&self) -> bool {
+        self.code() == Some(0)
+    }
+
+    pub fn code(&self) -> Option<i32> {
+        if self.exited() {
+            Some((self.0 >> 8) & 0xFF)
+        } else {
+            None
+        }
+    }
+
+    pub fn signal(&self) -> Option<i32> {
+        if !self.exited() {
+            Some(self.0 & 0x7F)
+        } else {
+            None
+        }
+    }
+}
+
+impl From<i32> for ExitStatus {
+    fn from(a: i32) -> ExitStatus {
+        ExitStatus(a)
+    }
+}
+
+impl fmt::Display for ExitStatus {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if let Some(code) = self.code() {
+            write!(f, "exit code: {}", code)
+        } else {
+            let signal = self.signal().unwrap();
+            write!(f, "signal: {}", signal)
+        }
+    }
+}
+
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+pub struct ExitCode(u8);
+
+impl ExitCode {
+    pub const SUCCESS: ExitCode = ExitCode(EXIT_SUCCESS as _);
+    pub const FAILURE: ExitCode = ExitCode(EXIT_FAILURE as _);
+
+    pub fn as_i32(&self) -> i32 {
+        self.0 as i32
+    }
+}
+
+/// The unique id of the process (this should never be negative).
+pub struct Process {
+    pid: usize,
+    status: Option<ExitStatus>,
+}
+
+impl Process {
+    pub fn id(&self) -> u32 {
+        self.pid as u32
+    }
+
+    pub fn kill(&mut self) -> io::Result<()> {
+        // If we've already waited on this process then the pid can be recycled
+        // and used for another process, and we probably shouldn't be killing
+        // random processes, so just return an error.
+        if self.status.is_some() {
+            Err(Error::new(ErrorKind::InvalidInput,
+                           "invalid argument: can't kill an exited process"))
+        } else {
+            cvt(syscall::kill(self.pid, syscall::SIGKILL))?;
+            Ok(())
+        }
+    }
+
+    pub fn wait(&mut self) -> io::Result<ExitStatus> {
+        if let Some(status) = self.status {
+            return Ok(status)
+        }
+        let mut status = 0;
+        cvt(syscall::waitpid(self.pid, &mut status, 0))?;
+        self.status = Some(ExitStatus(status as i32));
+        Ok(ExitStatus(status as i32))
+    }
+
+    pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
+        if let Some(status) = self.status {
+            return Ok(Some(status))
+        }
+        let mut status = 0;
+        let pid = cvt(syscall::waitpid(self.pid, &mut status, syscall::WNOHANG))?;
+        if pid == 0 {
+            Ok(None)
+        } else {
+            self.status = Some(ExitStatus(status as i32));
+            Ok(Some(ExitStatus(status as i32)))
+        }
+    }
+}