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.

Author: joboet

Diff for: library/std/src/sys/mod.rs

@@ -18,6 +18,7 @@ pub mod net;
 pub mod os_str;
 pub mod path;
 pub mod random;
+pub mod stdio;
 pub mod sync;
 pub mod thread_local;
 

Diff for: library/std/src/sys/pal/hermit/mod.rs

@@ -27,7 +27,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 

Diff for: library/std/src/sys/pal/hermit/stdio.rs

@@ -6,7 +6,7 @@ use core::sync::atomic::{AtomicUsize, Ordering};
 use crate::io::Write;
 
 // runtime features
-pub(super) mod panic;
+pub mod panic;
 mod reloc;
 
 // library features

Diff for: library/std/src/sys/pal/sgx/abi/mod.rs

@@ -4,6 +4,7 @@
 #![cfg(not(test))]
 
 use crate::sys::sync::RwLock;
+use crate::{slice, str};
 
 // Verify that the byte pattern libunwind uses to initialize an RwLock is
 // equivalent to the value of RwLock::new(). If the value changes,
@@ -44,3 +45,14 @@ pub unsafe extern "C" fn __rust_rwlock_unlock(p: *mut RwLock) -> i32 {
     unsafe { (*p).write_unlock() };
     return 0;
 }
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn __rust_print_err(m: *mut u8, s: i32) {
+    if s < 0 {
+        return;
+    }
+    let buf = unsafe { slice::from_raw_parts(m as *const u8, s as _) };
+    if let Ok(s) = str::from_utf8(&buf[..buf.iter().position(|&b| b == 0).unwrap_or(buf.len())]) {
+        eprint!("{s}");
+    }
+}

Diff for: library/std/src/sys/pal/sgx/libunwind_integration.rs

@@ -18,7 +18,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod thread_parking;
 pub mod time;

Diff for: library/std/src/sys/pal/sgx/mod.rs

@@ -27,7 +27,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub use self::itron::{thread, thread_parking};
 pub mod time;
 

Diff for: library/std/src/sys/pal/solid/mod.rs

@@ -16,7 +16,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub mod thread;
 #[allow(non_upper_case_globals)]
 #[path = "../unix/time.rs"]

Diff for: library/std/src/sys/pal/teeos/mod.rs

@@ -20,7 +20,6 @@ pub mod os;
 #[path = "../unsupported/pipe.rs"]
 pub mod pipe;
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 

Diff for: library/std/src/sys/pal/uefi/mod.rs

@@ -18,7 +18,6 @@ pub mod os;
 pub mod pipe;
 pub mod process;
 pub mod stack_overflow;
-pub mod stdio;
 pub mod sync;
 pub mod thread;
 pub mod thread_parking;

Diff for: library/std/src/sys/pal/unix/mod.rs

@@ -5,7 +5,6 @@ pub mod env;
 pub mod os;
 pub mod pipe;
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 

Diff for: library/std/src/sys/pal/unsupported/mod.rs

@@ -25,7 +25,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 

Diff for: library/std/src/sys/pal/wasi/mod.rs

@@ -22,8 +22,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-#[path = "../wasi/stdio.rs"]
-pub mod stdio;
 #[path = "../wasi/thread.rs"]
 pub mod thread;
 #[path = "../wasi/time.rs"]

Diff for: library/std/src/sys/pal/wasip2/mod.rs

@@ -25,8 +25,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-#[path = "../unsupported/stdio.rs"]
-pub mod stdio;
 #[path = "../unsupported/time.rs"]
 pub mod time;
 

Diff for: library/std/src/sys/pal/wasm/mod.rs

@@ -23,7 +23,6 @@ pub mod handle;
 pub mod os;
 pub mod pipe;
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 cfg_if::cfg_if! {

Diff for: library/std/src/sys/pal/windows/mod.rs

@@ -8,7 +8,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 pub mod thread;
 pub mod time;
 

Diff for: library/std/src/sys/pal/xous/mod.rs

@@ -19,7 +19,6 @@ pub mod os;
 pub mod pipe;
 #[path = "../unsupported/process.rs"]
 pub mod process;
-pub mod stdio;
 #[path = "../unsupported/thread.rs"]
 pub mod thread;
 #[path = "../unsupported/time.rs"]

Diff for: library/std/src/sys/pal/zkvm/mod.rs

@@ -0,0 +1,38 @@
+#![forbid(unsafe_op_in_unsafe_fn)]
+
+cfg_if::cfg_if! {
+    if #[cfg(any(
+        target_family = "unix",
+        target_os = "hermit"
+    ))] {
+        mod unix;
+        pub use unix::*;
+    } else if #[cfg(target_os = "windows")] {
+        mod windows;
+        pub use windows::*;
+    } else if #[cfg(all(target_vendor = "fortanix", target_env = "sgx"))] {
+        mod sgx;
+        pub use sgx::*;
+    } else if #[cfg(target_os = "solid_asp3")] {
+        mod solid;
+        pub use solid::*;
+    } else if #[cfg(target_os = "teeos")] {
+        mod teeos;
+        pub use teeos::*;
+    } else if #[cfg(target_os = "uefi")] {
+        mod uefi;
+        pub use uefi::*;
+    } else if #[cfg(target_os = "wasi")] {
+        mod wasi;
+        pub use wasi::*;
+    } else if #[cfg(target_os = "xous")] {
+        mod xous;
+        pub use xous::*;
+    } else if #[cfg(target_os = "zkvm")] {
+        mod zkvm;
+        pub use zkvm::*;
+    } else {
+        mod unsupported;
+        pub use unsupported::*;
+    }
+}

Diff for: library/std/src/sys/stdio/mod.rs

@@ -1,10 +1,6 @@
 use fortanix_sgx_abi as abi;
 
 use crate::io;
-#[cfg(not(test))]
-use crate::slice;
-#[cfg(not(test))]
-use crate::str;
 use crate::sys::fd::FileDesc;
 
 pub struct Stdin(());
@@ -70,19 +66,5 @@ pub fn is_ebadf(err: &io::Error) -> bool {
 }
 
 pub fn panic_output() -> Option<impl io::Write> {
-    super::abi::panic::SgxPanicOutput::new()
-}
-
-// This function is needed by libunwind. The symbol is named in pre-link args
-// for the target specification, so keep that in sync.
-#[cfg(not(test))]
-#[unsafe(no_mangle)]
-pub unsafe extern "C" fn __rust_print_err(m: *mut u8, s: i32) {
-    if s < 0 {
-        return;
-    }
-    let buf = unsafe { slice::from_raw_parts(m as *const u8, s as _) };
-    if let Ok(s) = str::from_utf8(&buf[..buf.iter().position(|&b| b == 0).unwrap_or(buf.len())]) {
-        eprint!("{s}");
-    }
+    crate::sys::pal::abi::panic::SgxPanicOutput::new()
 }

Diff for: library/std/src/sys/pal/sgx/stdio.rs renamed to library/std/src/sys/stdio/sgx.rs

@@ -1,5 +1,5 @@
-use super::abi;
 use crate::io;
+use crate::sys::pal::abi;
 
 pub struct Stdin;
 pub struct Stdout;

Diff for: library/std/src/sys/pal/solid/stdio.rs renamed to library/std/src/sys/stdio/solid.rs

@@ -1,5 +1,15 @@
-use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut};
+#[cfg(target_os = "hermit")]
+use hermit_abi::{EBADF, STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO};
+#[cfg(target_family = "unix")]
+use libc::{EBADF, STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO};
+
+#[cfg(target_family = "unix")]
+use crate::io::BorrowedCursor;
+use crate::io::{self, IoSlice, IoSliceMut};
 use crate::mem::ManuallyDrop;
+#[cfg(target_os = "hermit")]
+use crate::os::hermit::io::FromRawFd;
+#[cfg(target_family = "unix")]
 use crate::os::unix::io::FromRawFd;
 use crate::sys::fd::FileDesc;
 
@@ -15,15 +25,16 @@ impl Stdin {
 
 impl io::Read for Stdin {
     fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDIN_FILENO)).read(buf) }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDIN_FILENO)).read(buf) }
     }
 
+    #[cfg(not(target_os = "hermit"))]
     fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> io::Result<()> {
-        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDIN_FILENO)).read_buf(buf) }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDIN_FILENO)).read_buf(buf) }
     }
 
     fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
-        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDIN_FILENO)).read_vectored(bufs) }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDIN_FILENO)).read_vectored(bufs) }
     }
 
     #[inline]
@@ -40,13 +51,11 @@ impl Stdout {
 
 impl io::Write for Stdout {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDOUT_FILENO)).write(buf) }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDOUT_FILENO)).write(buf) }
     }
 
     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        unsafe {
-            ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDOUT_FILENO)).write_vectored(bufs)
-        }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDOUT_FILENO)).write_vectored(bufs) }
     }
 
     #[inline]
@@ -68,13 +77,11 @@ impl Stderr {
 
 impl io::Write for Stderr {
     fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
-        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDERR_FILENO)).write(buf) }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDERR_FILENO)).write(buf) }
     }
 
     fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
-        unsafe {
-            ManuallyDrop::new(FileDesc::from_raw_fd(libc::STDERR_FILENO)).write_vectored(bufs)
-        }
+        unsafe { ManuallyDrop::new(FileDesc::from_raw_fd(STDERR_FILENO)).write_vectored(bufs) }
     }
 
     #[inline]
@@ -89,7 +96,7 @@ impl io::Write for Stderr {
 }
 
 pub fn is_ebadf(err: &io::Error) -> bool {
-    err.raw_os_error() == Some(libc::EBADF as i32)
+    err.raw_os_error() == Some(EBADF as i32)
 }
 
 pub const STDIN_BUF_SIZE: usize = crate::sys::io::DEFAULT_BUF_SIZE;