Merge branch 'master' into redox

1 files changed, 480 insertions, 0 deletions

diff --git a/src/libstd/sys/unix/process/process_common.rs b/src/libstd/sys/unix/process/process_common.rs
new file mode 100644
index 00000000000..3497b266340
--- /dev/null
+++ b/src/libstd/sys/unix/process/process_common.rs
@@ -0,0 +1,480 @@
+// 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 os::unix::prelude::*;
+
+use collections::hash_map::{HashMap, Entry};
+use env;
+use ffi::{OsString, OsStr, CString, CStr};
+use fmt;
+use io;
+use libc::{self, c_int, gid_t, uid_t, c_char};
+use ptr;
+use sys::fd::FileDesc;
+use sys::fs::{File, OpenOptions};
+use sys::pipe::{self, AnonPipe};
+
+////////////////////////////////////////////////////////////////////////////////
+// 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: CString,
+    args: Vec<CString>,
+    env: Option<HashMap<OsString, (usize, CString)>>,
+    argv: Vec<*const c_char>,
+    envp: Option<Vec<*const c_char>>,
+
+    cwd: Option<CString>,
+    uid: Option<uid_t>,
+    gid: Option<gid_t>,
+    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
+pub struct ChildPipes {
+    pub stdin: ChildStdio,
+    pub stdout: ChildStdio,
+    pub stderr: ChildStdio,
+}
+
+pub enum ChildStdio {
+    Inherit,
+    Explicit(c_int),
+    Owned(FileDesc),
+}
+
+pub enum Stdio {
+    Inherit,
+    Null,
+    MakePipe,
+    Fd(FileDesc),
+}
+
+impl Command {
+    pub fn new(program: &OsStr) -> Command {
+        let mut saw_nul = false;
+        let program = os2c(program, &mut saw_nul);
+        Command {
+            argv: vec![program.as_ptr(), ptr::null()],
+            program: program,
+            args: Vec::new(),
+            env: None,
+            envp: None,
+            cwd: None,
+            uid: None,
+            gid: None,
+            saw_nul: saw_nul,
+            closures: Vec::new(),
+            stdin: None,
+            stdout: None,
+            stderr: None,
+        }
+    }
+
+    pub fn arg(&mut self, arg: &OsStr) {
+        // Overwrite the trailing NULL pointer in `argv` and then add a new null
+        // pointer.
+        let arg = os2c(arg, &mut self.saw_nul);
+        self.argv[self.args.len() + 1] = arg.as_ptr();
+        self.argv.push(ptr::null());
+
+        // Also make sure we keep track of the owned value to schedule a
+        // destructor for this memory.
+        self.args.push(arg);
+    }
+
+    fn init_env_map(&mut self) -> (&mut HashMap<OsString, (usize, CString)>,
+                                   &mut Vec<*const c_char>) {
+        if self.env.is_none() {
+            let mut map = HashMap::new();
+            let mut envp = Vec::new();
+            for (k, v) in env::vars_os() {
+                let s = pair_to_key(&k, &v, &mut self.saw_nul);
+                envp.push(s.as_ptr());
+                map.insert(k, (envp.len() - 1, s));
+            }
+            envp.push(ptr::null());
+            self.env = Some(map);
+            self.envp = Some(envp);
+        }
+        (self.env.as_mut().unwrap(), self.envp.as_mut().unwrap())
+    }
+
+    pub fn env(&mut self, key: &OsStr, val: &OsStr) {
+        let new_key = pair_to_key(key, val, &mut self.saw_nul);
+        let (map, envp) = self.init_env_map();
+
+        // If `key` is already present then we just update `envp` in place
+        // (and store the owned value), but if it's not there we override the
+        // trailing NULL pointer, add a new NULL pointer, and store where we
+        // were located.
+        match map.entry(key.to_owned()) {
+            Entry::Occupied(mut e) => {
+                let (i, ref mut s) = *e.get_mut();
+                envp[i] = new_key.as_ptr();
+                *s = new_key;
+            }
+            Entry::Vacant(e) => {
+                let len = envp.len();
+                envp[len - 1] = new_key.as_ptr();
+                envp.push(ptr::null());
+                e.insert((len - 1, new_key));
+            }
+        }
+    }
+
+    pub fn env_remove(&mut self, key: &OsStr) {
+        let (map, envp) = self.init_env_map();
+
+        // If we actually ended up removing a key, then we need to update the
+        // position of all keys that come after us in `envp` because they're all
+        // one element sooner now.
+        if let Some((i, _)) = map.remove(key) {
+            envp.remove(i);
+
+            for (_, &mut (ref mut j, _)) in map.iter_mut() {
+                if *j >= i {
+                    *j -= 1;
+                }
+            }
+        }
+    }
+
+    pub fn env_clear(&mut self) {
+        self.env = Some(HashMap::new());
+        self.envp = Some(vec![ptr::null()]);
+    }
+
+    pub fn cwd(&mut self, dir: &OsStr) {
+        self.cwd = Some(os2c(dir, &mut self.saw_nul));
+    }
+    pub fn uid(&mut self, id: uid_t) {
+        self.uid = Some(id);
+    }
+    pub fn gid(&mut self, id: gid_t) {
+        self.gid = Some(id);
+    }
+
+    pub fn saw_nul(&self) -> bool {
+        self.saw_nul
+    }
+    pub fn get_envp(&self) -> &Option<Vec<*const c_char>> {
+        &self.envp
+    }
+    pub fn get_argv(&self) -> &Vec<*const c_char> {
+        &self.argv
+    }
+
+    #[allow(dead_code)]
+    pub fn get_cwd(&self) -> &Option<CString> {
+        &self.cwd
+    }
+    #[allow(dead_code)]
+    pub fn get_uid(&self) -> Option<uid_t> {
+        self.uid
+    }
+    #[allow(dead_code)]
+    pub fn get_gid(&self) -> Option<gid_t> {
+        self.gid
+    }
+
+    pub fn get_closures(&mut self) -> &mut Vec<Box<FnMut() -> io::Result<()> + Send + Sync>> {
+        &mut self.closures
+    }
+
+    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 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))
+    }
+}
+
+fn os2c(s: &OsStr, saw_nul: &mut bool) -> CString {
+    CString::new(s.as_bytes()).unwrap_or_else(|_e| {
+        *saw_nul = true;
+        CString::new("<string-with-nul>").unwrap()
+    })
+}
+
+impl Stdio {
+    pub 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() >= 0 && fd.raw() <= libc::STDERR_FILENO {
+                    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 path = unsafe {
+                    CStr::from_ptr("/dev/null\0".as_ptr() as *const _)
+                };
+                let fd = File::open_c(&path, &opts)?;
+                Ok((ChildStdio::Owned(fd.into_fd()), None))
+            }
+        }
+    }
+}
+
+impl ChildStdio {
+    pub fn fd(&self) -> Option<c_int> {
+        match *self {
+            ChildStdio::Inherit => None,
+            ChildStdio::Explicit(fd) => Some(fd),
+            ChildStdio::Owned(ref fd) => Some(fd.raw()),
+        }
+    }
+}
+
+fn pair_to_key(key: &OsStr, value: &OsStr, saw_nul: &mut bool) -> CString {
+    let (key, value) = (key.as_bytes(), value.as_bytes());
+    let mut v = Vec::with_capacity(key.len() + value.len() + 1);
+    v.extend(key);
+    v.push(b'=');
+    v.extend(value);
+    CString::new(v).unwrap_or_else(|_e| {
+        *saw_nul = true;
+        CString::new("foo=bar").unwrap()
+    })
+}
+
+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(())
+    }
+}
+
+/// Unix exit statuses
+#[derive(PartialEq, Eq, Clone, Copy, Debug)]
+pub struct ExitStatus(c_int);
+
+impl ExitStatus {
+    pub fn new(status: c_int) -> ExitStatus {
+        ExitStatus(status)
+    }
+
+    fn exited(&self) -> bool {
+        unsafe { libc::WIFEXITED(self.0) }
+    }
+
+    pub fn success(&self) -> bool {
+        self.code() == Some(0)
+    }
+
+    pub fn code(&self) -> Option<i32> {
+        if self.exited() {
+            Some(unsafe { libc::WEXITSTATUS(self.0) })
+        } else {
+            None
+        }
+    }
+
+    pub fn signal(&self) -> Option<i32> {
+        if !self.exited() {
+            Some(unsafe { libc::WTERMSIG(self.0) })
+        } else {
+            None
+        }
+    }
+}
+
+impl From<c_int> for ExitStatus {
+    fn from(a: c_int) -> 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)
+        }
+    }
+}
+
+#[cfg(all(test, not(target_os = "emscripten")))]
+mod tests {
+    use super::*;
+
+    use ffi::OsStr;
+    use mem;
+    use ptr;
+    use libc;
+    use sys::cvt;
+
+    macro_rules! t {
+        ($e:expr) => {
+            match $e {
+                Ok(t) => t,
+                Err(e) => panic!("received error for `{}`: {}", stringify!($e), e),
+            }
+        }
+    }
+
+    #[cfg(not(target_os = "android"))]
+    extern {
+        #[cfg_attr(target_os = "netbsd", link_name = "__sigaddset14")]
+        fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int;
+    }
+
+    #[cfg(target_os = "android")]
+    unsafe fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int {
+        use slice;
+
+        let raw = slice::from_raw_parts_mut(set as *mut u8, mem::size_of::<libc::sigset_t>());
+        let bit = (signum - 1) as usize;
+        raw[bit / 8] |= 1 << (bit % 8);
+        return 0;
+    }
+
+    // See #14232 for more information, but it appears that signal delivery to a
+    // newly spawned process may just be raced in the OSX, so to prevent this
+    // test from being flaky we ignore it on OSX.
+    #[test]
+    #[cfg_attr(target_os = "macos", ignore)]
+    #[cfg_attr(target_os = "nacl", ignore)] // no signals on NaCl.
+    fn test_process_mask() {
+        unsafe {
+            // Test to make sure that a signal mask does not get inherited.
+            let mut cmd = Command::new(OsStr::new("cat"));
+
+            let mut set: libc::sigset_t = mem::uninitialized();
+            let mut old_set: libc::sigset_t = mem::uninitialized();
+            t!(cvt(libc::sigemptyset(&mut set)));
+            t!(cvt(sigaddset(&mut set, libc::SIGINT)));
+            t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set, &mut old_set)));
+
+            cmd.stdin(Stdio::MakePipe);
+            cmd.stdout(Stdio::MakePipe);
+
+            let (mut cat, mut pipes) = t!(cmd.spawn(Stdio::Null, true));
+            let stdin_write = pipes.stdin.take().unwrap();
+            let stdout_read = pipes.stdout.take().unwrap();
+
+            t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &old_set,
+                                         ptr::null_mut())));
+
+            t!(cvt(libc::kill(cat.id() as libc::pid_t, libc::SIGINT)));
+            // We need to wait until SIGINT is definitely delivered. The
+            // easiest way is to write something to cat, and try to read it
+            // back: if SIGINT is unmasked, it'll get delivered when cat is
+            // next scheduled.
+            let _ = stdin_write.write(b"Hello");
+            drop(stdin_write);
+
+            // Either EOF or failure (EPIPE) is okay.
+            let mut buf = [0; 5];
+            if let Ok(ret) = stdout_read.read(&mut buf) {
+                assert!(ret == 0);
+            }
+
+            t!(cat.wait());
+        }
+    }
+}