std: move exit out of PAL

library/std/src/process.rs

@@ -2464,7 +2464,7 @@ pub fn wait_with_output(mut self) -> io::Result<Output> {
 #[cfg_attr(not(test), rustc_diagnostic_item = "process_exit")]
 pub fn exit(code: i32) -> ! {
     crate::rt::cleanup();
-    crate::sys::os::exit(code)
+    crate::sys::exit::exit(code)
 }
 
 /// Terminates the process in an abnormal fashion.

library/std/src/rt.rs

@@ -187,7 +187,7 @@ fn lang_start_internal(
         cleanup();
         // Guard against multiple threads calling `libc::exit` concurrently.
         // See the documentation for `unique_thread_exit` for more information.
-        crate::sys::exit_guard::unique_thread_exit();
+        crate::sys::exit::unique_thread_exit();
 
         ret_code
     })

library/std/src/sys/exit.rs

@@ -19,8 +19,7 @@
         /// * If it is called again on the same thread as the first call, it will abort.
         /// * If it is called again on a different thread, it will wait in a loop
         ///   (waiting for the process to exit).
-        #[cfg_attr(any(test, doctest), allow(dead_code))]
-        pub(crate) fn unique_thread_exit() {
+        pub fn unique_thread_exit() {
             use crate::ffi::c_int;
             use crate::ptr;
             use crate::sync::atomic::AtomicPtr;
@@ -62,9 +61,83 @@ pub(crate) fn unique_thread_exit() {
         ///
         /// Mitigation is ***NOT*** implemented on this platform, either because this platform
         /// is not affected, or because mitigation is not yet implemented for this platform.
-        #[cfg_attr(any(test, doctest), allow(dead_code))]
-        pub(crate) fn unique_thread_exit() {
+        #[cfg_attr(any(test, doctest), expect(dead_code))]
+        pub fn unique_thread_exit() {
             // Mitigation not required on platforms where `exit` is thread-safe.
         }
     }
 }
+
+pub fn exit(code: i32) -> ! {
+    cfg_select! {
+        target_os = "hermit" => {
+            unsafe { hermit_abi::exit(code) }
+        }
+        target_os = "linux" => {
+            unsafe {
+                unique_thread_exit();
+                libc::exit(code)
+            }
+        }
+        target_os = "motor" => {
+            moto_rt::process::exit(code)
+        }
+        all(target_vendor = "fortanix", target_env = "sgx") => {
+            crate::sys::pal::abi::exit_with_code(code as _)
+        }
+        target_os = "solid_asp3" => {
+            rtabort!("exit({}) called", code)
+        }
+        target_os = "teeos" => {
+            let _ = code;
+            panic!("TA should not call `exit`")
+        }
+        target_os = "uefi" => {
+            use r_efi::base::Status;
+
+            use crate::os::uefi::env;
+
+            if let (Some(boot_services), Some(handle)) =
+                (env::boot_services(), env::try_image_handle())
+            {
+                let boot_services = boot_services.cast::<r_efi::efi::BootServices>();
+                let _ = unsafe {
+                    ((*boot_services.as_ptr()).exit)(
+                        handle.as_ptr(),
+                        Status::from_usize(code as usize),
+                        0,
+                        crate::ptr::null_mut(),
+                    )
+                };
+            }
+            crate::intrinsics::abort()
+        }
+        any(
+            target_family = "unix",
+            target_os = "wasi",
+        ) => {
+            unsafe { libc::exit(code as crate::ffi::c_int) }
+        }
+        target_os = "vexos" => {
+            let _ = code;
+
+            unsafe {
+                vex_sdk::vexSystemExitRequest();
+
+                loop {
+                    vex_sdk::vexTasksRun();
+                }
+            }
+        }
+        target_os = "windows" => {
+            unsafe { crate::sys::pal::c::ExitProcess(code as u32) }
+        }
+        target_os = "xous" => {
+            crate::os::xous::ffi::exit(code as u32)
+        }
+        _ => {
+            let _ = code;
+            crate::intrinsics::abort()
+        }
+    }
+}

library/std/src/sys/mod.rs

@@ -11,7 +11,7 @@
 pub mod cmath;
 pub mod env;
 pub mod env_consts;
-pub mod exit_guard;
+pub mod exit;
 pub mod fd;
 pub mod fs;
 pub mod io;

library/std/src/sys/pal/hermit/os.rs

@@ -57,10 +57,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    unsafe { hermit_abi::exit(code) }
-}
-
 pub fn getpid() -> u32 {
     unsafe { hermit_abi::getpid() as u32 }
 }

library/std/src/sys/pal/motor/os.rs

@@ -63,10 +63,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    moto_rt::process::exit(code)
-}
-
 pub fn getpid() -> u32 {
     panic!("Pids on Motor OS are u64.")
 }

library/std/src/sys/pal/sgx/abi/mod.rs

@@ -96,7 +96,7 @@ extern "C" fn entry(p1: u64, p2: u64, p3: u64, secondary: bool, p4: u64, p5: u64
     }
 }
 
-pub(super) fn exit_with_code(code: isize) -> ! {
+pub fn exit_with_code(code: isize) -> ! {
     if code != 0 {
         if let Some(mut out) = panic::SgxPanicOutput::new() {
             let _ = write!(out, "Exited with status code {code}");

library/std/src/sys/pal/sgx/os.rs

@@ -56,10 +56,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    super::abi::exit_with_code(code as _)
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids in SGX")
 }

library/std/src/sys/pal/solid/os.rs

@@ -63,10 +63,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    rtabort!("exit({}) called", code);
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }

library/std/src/sys/pal/teeos/os.rs

@@ -67,10 +67,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(_code: i32) -> ! {
-    panic!("TA should not call `exit`")
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }

library/std/src/sys/pal/uefi/os.rs

@@ -1,13 +1,10 @@
-use r_efi::efi::Status;
 use r_efi::efi::protocols::{device_path, loaded_image_device_path};
 
 use super::{helpers, unsupported_err};
 use crate::ffi::{OsStr, OsString};
 use crate::marker::PhantomData;
-use crate::os::uefi;
 use crate::os::uefi::ffi::{OsStrExt, OsStringExt};
 use crate::path::{self, PathBuf};
-use crate::ptr::NonNull;
 use crate::{fmt, io};
 
 const PATHS_SEP: u16 = b';' as u16;
@@ -105,23 +102,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    if let (Some(boot_services), Some(handle)) =
-        (uefi::env::boot_services(), uefi::env::try_image_handle())
-    {
-        let boot_services: NonNull<r_efi::efi::BootServices> = boot_services.cast();
-        let _ = unsafe {
-            ((*boot_services.as_ptr()).exit)(
-                handle.as_ptr(),
-                Status::from_usize(code as usize),
-                0,
-                crate::ptr::null_mut(),
-            )
-        };
-    }
-    crate::intrinsics::abort()
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }

library/std/src/sys/pal/unix/os.rs

@@ -533,11 +533,6 @@ unsafe fn fallback() -> Option<OsString> {
     }
 }
 
-pub fn exit(code: i32) -> ! {
-    crate::sys::exit_guard::unique_thread_exit();
-    unsafe { libc::exit(code as c_int) }
-}
-
 pub fn getpid() -> u32 {
     unsafe { libc::getpid() as u32 }
 }

library/std/src/sys/pal/unsupported/os.rs

@@ -56,10 +56,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(_code: i32) -> ! {
-    crate::intrinsics::abort()
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }

library/std/src/sys/pal/vexos/mod.rs

@@ -1,3 +1,4 @@
+#[path = "../unsupported/os.rs"]
 pub mod os;
 
 #[expect(dead_code)]

library/std/src/sys/pal/vexos/os.rs

@@ -1,19 +0,0 @@
-#[expect(dead_code)]
-#[path = "../unsupported/os.rs"]
-mod unsupported_os;
-pub use unsupported_os::{
-    JoinPathsError, SplitPaths, chdir, current_exe, getcwd, getpid, home_dir, join_paths,
-    split_paths, temp_dir,
-};
-
-pub use super::unsupported;
-
-pub fn exit(_code: i32) -> ! {
-    unsafe {
-        vex_sdk::vexSystemExitRequest();
-
-        loop {
-            vex_sdk::vexTasksRun();
-        }
-    }
-}

library/std/src/sys/pal/wasi/os.rs

@@ -102,10 +102,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    unsafe { libc::exit(code) }
-}
-
 pub fn getpid() -> u32 {
     panic!("unsupported");
 }

library/std/src/sys/pal/windows/os.rs

@@ -189,10 +189,6 @@ pub fn home_dir() -> Option<PathBuf> {
         .or_else(home_dir_crt)
 }
 
-pub fn exit(code: i32) -> ! {
-    unsafe { c::ExitProcess(code as u32) }
-}
-
 pub fn getpid() -> u32 {
     unsafe { c::GetCurrentProcessId() }
 }

library/std/src/sys/pal/xous/os.rs

@@ -119,10 +119,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(code: i32) -> ! {
-    crate::os::xous::ffi::exit(code as u32);
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }

library/std/src/sys/pal/zkvm/os.rs

@@ -56,10 +56,6 @@ pub fn home_dir() -> Option<PathBuf> {
     None
 }
 
-pub fn exit(_code: i32) -> ! {
-    crate::intrinsics::abort()
-}
-
 pub fn getpid() -> u32 {
     panic!("no pids on this platform")
 }