Update Trusty support to account for recent libstd reorganization

2 files changed, 84 insertions, 0 deletions

diff --git a/library/std/src/sys/stdio/mod.rs b/library/std/src/sys/stdio/mod.rs
index 2a9167bfe96..336d4c8527d 100644
--- a/library/std/src/sys/stdio/mod.rs
+++ b/library/std/src/sys/stdio/mod.rs
@@ -19,6 +19,9 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "teeos")] {
         mod teeos;
         pub use teeos::*;
+    } else if #[cfg(target_os = "trusty")] {
+        mod trusty;
+        pub use trusty::*;
     } else if #[cfg(target_os = "uefi")] {
         mod uefi;
         pub use uefi::*;
diff --git a/library/std/src/sys/stdio/trusty.rs b/library/std/src/sys/stdio/trusty.rs
new file mode 100644
index 00000000000..d393e95394d
--- /dev/null
+++ b/library/std/src/sys/stdio/trusty.rs
@@ -0,0 +1,81 @@
+use crate::io;
+
+pub struct Stdin;
+pub struct Stdout;
+pub struct Stderr;
+
+impl Stdin {
+    pub const fn new() -> Stdin {
+        Stdin
+    }
+}
+
+impl io::Read for Stdin {
+    fn read(&mut self, _buf: &mut [u8]) -> io::Result<usize> {
+        Ok(0)
+    }
+}
+
+impl Stdout {
+    pub const fn new() -> Stdout {
+        Stdout
+    }
+}
+
+impl io::Write for Stdout {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        _write(libc::STDOUT_FILENO, buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl Stderr {
+    pub const fn new() -> Stderr {
+        Stderr
+    }
+}
+
+impl io::Write for Stderr {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        _write(libc::STDERR_FILENO, buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+pub const STDIN_BUF_SIZE: usize = 0;
+
+pub fn is_ebadf(_err: &io::Error) -> bool {
+    true
+}
+
+pub fn panic_output() -> Option<impl io::Write> {
+    Some(Stderr)
+}
+
+fn _write(fd: i32, message: &[u8]) -> io::Result<usize> {
+    let mut iov = libc::iovec { iov_base: message.as_ptr() as *mut _, iov_len: message.len() };
+    loop {
+        // SAFETY: syscall, safe arguments.
+        let ret = unsafe { libc::writev(fd, &iov, 1) };
+        if ret < 0 {
+            return Err(io::Error::last_os_error());
+        }
+        let ret = ret as usize;
+        if ret > iov.iov_len {
+            return Err(io::Error::last_os_error());
+        }
+        if ret == iov.iov_len {
+            return Ok(message.len());
+        }
+        // SAFETY: ret has been checked to be less than the length of
+        // the buffer
+        iov.iov_base = unsafe { iov.iov_base.add(ret) };
+        iov.iov_len -= ret;
+    }
+}