From a6ed319e1b1391181d08a40e3fb8f8a1412d2222 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eduardo=20S=C3=A1nchez=20Mu=C3=B1oz?= <eduardosm-dev@e64.io>
Date: Fri, 12 Apr 2024 20:47:59 +0200
Subject: [PATCH] Add `unsafe` to two functions with safety invariants

---
 library/std/src/sys/pal/windows/thread.rs | 26 ++++++++++++-----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/library/std/src/sys/pal/windows/thread.rs b/library/std/src/sys/pal/windows/thread.rs
index 34d90a3b4a0dc..70099e0a3b560 100644
--- a/library/std/src/sys/pal/windows/thread.rs
+++ b/library/std/src/sys/pal/windows/thread.rs
@@ -45,13 +45,11 @@ impl Thread {
             Err(io::Error::last_os_error())
         };
 
-        extern "system" fn thread_start(main: *mut c_void) -> c::DWORD {
-            unsafe {
-                // Next, reserve some stack space for if we otherwise run out of stack.
-                stack_overflow::reserve_stack();
-                // Finally, let's run some code.
-                Box::from_raw(main as *mut Box<dyn FnOnce()>)();
-            }
+        unsafe extern "system" fn thread_start(main: *mut c_void) -> c::DWORD {
+            // Next, reserve some stack space for if we otherwise run out of stack.
+            stack_overflow::reserve_stack();
+            // Finally, let's run some code.
+            Box::from_raw(main as *mut Box<dyn FnOnce()>)();
             0
         }
     }
@@ -59,15 +57,19 @@ impl Thread {
     pub fn set_name(name: &CStr) {
         if let Ok(utf8) = name.to_str() {
             if let Ok(utf16) = to_u16s(utf8) {
-                Self::set_name_wide(&utf16)
+                unsafe {
+                    // SAFETY: the vec returned by `to_u16s` ends with a zero value
+                    Self::set_name_wide(&utf16)
+                }
             };
         };
     }
 
-    pub fn set_name_wide(name: &[u16]) {
-        unsafe {
-            c::SetThreadDescription(c::GetCurrentThread(), name.as_ptr());
-        };
+    /// # Safety
+    ///
+    /// `name` must end with a zero value
+    pub unsafe fn set_name_wide(name: &[u16]) {
+        c::SetThreadDescription(c::GetCurrentThread(), name.as_ptr());
     }
 
     pub fn join(self) {