Auto merge of #136780 - joboet:move_pal_stdio, r=Amanieu

std: move stdio to `sys`

As per #117276, this moves the platform definitions of `Stdout` and friends into `sys`. This PR also unifies the UNIX and Hermit implementations and moves the `__rust_print_err` function needed by libunwind on SGX into the dedicated module for such helper functions.

1 files changed, 70 insertions, 0 deletions

diff --git a/library/std/src/sys/stdio/sgx.rs b/library/std/src/sys/stdio/sgx.rs
new file mode 100644
index 00000000000..03d754cb217
--- /dev/null
+++ b/library/std/src/sys/stdio/sgx.rs
@@ -0,0 +1,70 @@
+use fortanix_sgx_abi as abi;
+
+use crate::io;
+use crate::sys::fd::FileDesc;
+
+pub struct Stdin(());
+pub struct Stdout(());
+pub struct Stderr(());
+
+fn with_std_fd<F: FnOnce(&FileDesc) -> R, R>(fd: abi::Fd, f: F) -> R {
+    let fd = FileDesc::new(fd);
+    let ret = f(&fd);
+    fd.into_raw();
+    ret
+}
+
+impl Stdin {
+    pub const fn new() -> Stdin {
+        Stdin(())
+    }
+}
+
+impl io::Read for Stdin {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        with_std_fd(abi::FD_STDIN, |fd| fd.read(buf))
+    }
+}
+
+impl Stdout {
+    pub const fn new() -> Stdout {
+        Stdout(())
+    }
+}
+
+impl io::Write for Stdout {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        with_std_fd(abi::FD_STDOUT, |fd| fd.write(buf))
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        with_std_fd(abi::FD_STDOUT, |fd| fd.flush())
+    }
+}
+
+impl Stderr {
+    pub const fn new() -> Stderr {
+        Stderr(())
+    }
+}
+
+impl io::Write for Stderr {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        with_std_fd(abi::FD_STDERR, |fd| fd.write(buf))
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        with_std_fd(abi::FD_STDERR, |fd| fd.flush())
+    }
+}
+
+pub const STDIN_BUF_SIZE: usize = crate::sys::io::DEFAULT_BUF_SIZE;
+
+pub fn is_ebadf(err: &io::Error) -> bool {
+    // FIXME: Rust normally maps Unix EBADF to `Uncategorized`
+    err.raw_os_error() == Some(abi::Error::BrokenPipe as _)
+}
+
+pub fn panic_output() -> Option<impl io::Write> {
+    crate::sys::pal::abi::panic::SgxPanicOutput::new()
+}