4 files changed, 28 insertions, 16 deletions
diff --git a/library/std/src/sys_common/mod.rs b/library/std/src/sys_common/mod.rs
index e9c727cbb..e18638f2a 100644
--- a/library/std/src/sys_common/mod.rs
+++ b/library/std/src/sys_common/mod.rs
@@ -44,8 +44,10 @@ cfg_if::cfg_if! {
 
 cfg_if::cfg_if! {
     if #[cfg(any(target_os = "l4re",
+                 target_os = "uefi",
                  feature = "restricted-std",
                  all(target_family = "wasm", not(target_os = "emscripten")),
+                 target_os = "xous",
                  all(target_vendor = "fortanix", target_env = "sgx")))] {
         pub use crate::sys::net;
     } else {
diff --git a/library/std/src/sys_common/net.rs b/library/std/src/sys_common/net.rs
index 2976a9f57..4f5b17dea 100644
--- a/library/std/src/sys_common/net.rs
+++ b/library/std/src/sys_common/net.rs
@@ -32,6 +32,7 @@ cfg_if::cfg_if! {
 cfg_if::cfg_if! {
     if #[cfg(any(
         target_os = "linux", target_os = "android",
+        target_os = "hurd",
         target_os = "dragonfly", target_os = "freebsd",
         target_os = "openbsd", target_os = "netbsd",
         target_os = "haiku", target_os = "nto"))] {
diff --git a/library/std/src/sys_common/process.rs b/library/std/src/sys_common/process.rs
index 18883048d..4d295cf0f 100644
--- a/library/std/src/sys_common/process.rs
+++ b/library/std/src/sys_common/process.rs
@@ -80,6 +80,10 @@ impl CommandEnv {
         self.vars.clear();
     }
 
+    pub fn does_clear(&self) -> bool {
+        self.clear
+    }
+
     pub fn have_changed_path(&self) -> bool {
         self.saw_path || self.clear
     }
diff --git a/library/std/src/sys_common/thread_info.rs b/library/std/src/sys_common/thread_info.rs
index 88d937a7d..8d51732e0 100644
--- a/library/std/src/sys_common/thread_info.rs
+++ b/library/std/src/sys_common/thread_info.rs
@@ -1,46 +1,51 @@
 #![allow(dead_code)] // stack_guard isn't used right now on all platforms
 
-use crate::cell::RefCell;
+use crate::cell::OnceCell;
 use crate::sys::thread::guard::Guard;
 use crate::thread::Thread;
 
 struct ThreadInfo {
-    stack_guard: Option<Guard>,
-    thread: Thread,
+    stack_guard: OnceCell<Guard>,
+    thread: OnceCell<Thread>,
 }
 
-thread_local! { static THREAD_INFO: RefCell<Option<ThreadInfo>> = const { RefCell::new(None) } }
+thread_local! {
+   static THREAD_INFO: ThreadInfo = const { ThreadInfo {
+       stack_guard: OnceCell::new(),
+       thread: OnceCell::new()
+   } };
+}
 
 impl ThreadInfo {
     fn with<R, F>(f: F) -> Option<R>
     where
-        F: FnOnce(&mut ThreadInfo) -> R,
+        F: FnOnce(&Thread, &OnceCell<Guard>) -> R,
     {
         THREAD_INFO
             .try_with(move |thread_info| {
-                let mut thread_info = thread_info.borrow_mut();
-                let thread_info = thread_info.get_or_insert_with(|| ThreadInfo {
-                    stack_guard: None,
-                    thread: Thread::new(None),
-                });
-                f(thread_info)
+                let thread = thread_info.thread.get_or_init(|| Thread::new(None));
+                f(thread, &thread_info.stack_guard)
             })
             .ok()
     }
 }
 
 pub fn current_thread() -> Option<Thread> {
-    ThreadInfo::with(|info| info.thread.clone())
+    ThreadInfo::with(|thread, _| thread.clone())
 }
 
 pub fn stack_guard() -> Option<Guard> {
-    ThreadInfo::with(|info| info.stack_guard.clone()).and_then(|o| o)
+    ThreadInfo::with(|_, guard| guard.get().cloned()).flatten()
 }
 
+/// Set new thread info, panicking if it has already been initialized
+#[allow(unreachable_code, unreachable_patterns)] // some platforms don't use stack_guard
 pub fn set(stack_guard: Option<Guard>, thread: Thread) {
     THREAD_INFO.with(move |thread_info| {
-        let mut thread_info = thread_info.borrow_mut();
-        rtassert!(thread_info.is_none());
-        *thread_info = Some(ThreadInfo { stack_guard, thread });
+        rtassert!(thread_info.stack_guard.get().is_none() && thread_info.thread.get().is_none());
+        if let Some(guard) = stack_guard {
+            thread_info.stack_guard.set(guard).unwrap();
+        }
+        thread_info.thread.set(thread).unwrap();
     });
 }