Auto merge of #87269 - GuillaumeGomez:rollup-qukedv0, r=GuillaumeGomez

Rollup of 8 pull requests

Successful merges:

 - #86230 (Add --nocapture option to rustdoc)
 - #87210 (Rustdoc accessibility: make the sidebar headers actual headers)
 - #87227 (Move asm! and global_asm! to core::arch)
 - #87236 (Simplify command-line argument initialization on unix)
 - #87251 (Fix "item info" width)
 - #87256 (Extend HIR-based WF checking to associated type defaults)
 - #87259 (triagebot shortcut config)
 - #87268 (Don't create references to uninitialized data in `List::from_arena`)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 3 insertions, 22 deletions

diff --git a/library/std/src/sys/unix/args.rs b/library/std/src/sys/unix/args.rs
index fc423e393d4..ad93fa610c4 100644
--- a/library/std/src/sys/unix/args.rs
+++ b/library/std/src/sys/unix/args.rs
@@ -14,11 +14,6 @@ pub unsafe fn init(argc: isize, argv: *const *const u8) {
     imp::init(argc, argv)
 }
 
-/// One-time global cleanup.
-pub unsafe fn cleanup() {
-    imp::cleanup()
-}
-
 /// Returns the command line arguments
 pub fn args() -> Args {
     imp::args()
@@ -82,16 +77,10 @@ mod imp {
     use crate::ptr;
     use crate::sync::atomic::{AtomicIsize, AtomicPtr, Ordering};
 
-    use crate::sys_common::mutex::StaticMutex;
-
     static ARGC: AtomicIsize = AtomicIsize::new(0);
     static ARGV: AtomicPtr<*const u8> = AtomicPtr::new(ptr::null_mut());
-    // We never call `ENV_LOCK.init()`, so it is UB to attempt to
-    // acquire this mutex reentrantly!
-    static LOCK: StaticMutex = StaticMutex::new();
 
     unsafe fn really_init(argc: isize, argv: *const *const u8) {
-        let _guard = LOCK.lock();
         ARGC.store(argc, Ordering::Relaxed);
         ARGV.store(argv as *mut _, Ordering::Relaxed);
     }
@@ -127,21 +116,16 @@ mod imp {
         init_wrapper
     };
 
-    pub unsafe fn cleanup() {
-        let _guard = LOCK.lock();
-        ARGC.store(0, Ordering::Relaxed);
-        ARGV.store(ptr::null_mut(), Ordering::Relaxed);
-    }
-
     pub fn args() -> Args {
         Args { iter: clone().into_iter() }
     }
 
     fn clone() -> Vec<OsString> {
         unsafe {
-            let _guard = LOCK.lock();
-            let argc = ARGC.load(Ordering::Relaxed);
+            // Load ARGC and ARGV without a lock. If the store to either ARGV or
+            // ARGC isn't visible yet, we'll return an empty argument list.
             let argv = ARGV.load(Ordering::Relaxed);
+            let argc = if argv.is_null() { 0 } else { ARGC.load(Ordering::Relaxed) };
             (0..argc)
                 .map(|i| {
                     let cstr = CStr::from_ptr(*argv.offset(i) as *const libc::c_char);
@@ -159,8 +143,6 @@ mod imp {
 
     pub unsafe fn init(_argc: isize, _argv: *const *const u8) {}
 
-    pub fn cleanup() {}
-
     #[cfg(target_os = "macos")]
     pub fn args() -> Args {
         use crate::os::unix::prelude::*;
diff --git a/library/std/src/sys/unix/mod.rs b/library/std/src/sys/unix/mod.rs
index 2da71b2a448..9e553ec7682 100644
--- a/library/std/src/sys/unix/mod.rs
+++ b/library/std/src/sys/unix/mod.rs
@@ -123,7 +123,6 @@ pub unsafe fn init(argc: isize, argv: *const *const u8) {
 // SAFETY: must be called only once during runtime cleanup.
 // NOTE: this is not guaranteed to run, for example when the program aborts.
 pub unsafe fn cleanup() {
-    args::cleanup();
     stack_overflow::cleanup();
 }