Auto merge of #83573 - JohnTitor:rollup-28jnzsr, r=JohnTitor

Rollup of 10 pull requests

Successful merges:

 - #79399 (Use detailed and shorter fs error explaination)
 - #83348 (format macro argument parsing fix)
 - #83462 (ExitStatus: print "exit status: {}" rather than "exit code: {}" on unix)
 - #83526 (lazily calls some fns)
 - #83558 (Use DebugStruct::finish_non_exhaustive() in std.)
 - #83559 (Fix Debug implementation for RwLock{Read,Write}Guard.)
 - #83560 (Derive Debug for io::Chain instead of manually implementing it.)
 - #83561 (Improve Debug implementations of Mutex and RwLock.)
 - #83567 (Update rustup cross-compilation docs link)
 - #83569 (Add regression tests for #56445)

Failed merges:

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

13 files changed, 46 insertions, 38 deletions

diff --git a/library/std/src/collections/hash/map.rs b/library/std/src/collections/hash/map.rs
index ed32668456d..3dcc5cd2b59 100644
--- a/library/std/src/collections/hash/map.rs
+++ b/library/std/src/collections/hash/map.rs
@@ -1793,7 +1793,7 @@ impl<'a, K, V, S> RawVacantEntryMut<'a, K, V, S> {
 #[unstable(feature = "hash_raw_entry", issue = "56167")]
 impl<K, V, S> Debug for RawEntryBuilderMut<'_, K, V, S> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RawEntryBuilder").finish()
+        f.debug_struct("RawEntryBuilder").finish_non_exhaustive()
     }
 }
 
@@ -1813,21 +1813,21 @@ impl<K: Debug, V: Debug, S> Debug for RawOccupiedEntryMut<'_, K, V, S> {
         f.debug_struct("RawOccupiedEntryMut")
             .field("key", self.key())
             .field("value", self.get())
-            .finish()
+            .finish_non_exhaustive()
     }
 }
 
 #[unstable(feature = "hash_raw_entry", issue = "56167")]
 impl<K, V, S> Debug for RawVacantEntryMut<'_, K, V, S> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RawVacantEntryMut").finish()
+        f.debug_struct("RawVacantEntryMut").finish_non_exhaustive()
     }
 }
 
 #[unstable(feature = "hash_raw_entry", issue = "56167")]
 impl<K, V, S> Debug for RawEntryBuilder<'_, K, V, S> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RawEntryBuilder").finish()
+        f.debug_struct("RawEntryBuilder").finish_non_exhaustive()
     }
 }
 
@@ -1867,7 +1867,10 @@ pub struct OccupiedEntry<'a, K: 'a, V: 'a> {
 #[stable(feature = "debug_hash_map", since = "1.12.0")]
 impl<K: Debug, V: Debug> Debug for OccupiedEntry<'_, K, V> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("OccupiedEntry").field("key", self.key()).field("value", self.get()).finish()
+        f.debug_struct("OccupiedEntry")
+            .field("key", self.key())
+            .field("value", self.get())
+            .finish_non_exhaustive()
     }
 }
 
@@ -1903,7 +1906,7 @@ impl<K: Debug, V: Debug> Debug for OccupiedError<'_, K, V> {
             .field("key", self.entry.key())
             .field("old_value", self.entry.get())
             .field("new_value", &self.value)
-            .finish()
+            .finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/fs.rs b/library/std/src/fs.rs
index ccbc69a975c..860bc130b7d 100644
--- a/library/std/src/fs.rs
+++ b/library/std/src/fs.rs
@@ -1154,7 +1154,7 @@ impl fmt::Debug for Metadata {
             .field("modified", &self.modified())
             .field("accessed", &self.accessed())
             .field("created", &self.created())
-            .finish()
+            .finish_non_exhaustive()
     }
 }
 
@@ -1677,9 +1677,9 @@ pub fn rename<P: AsRef<Path>, Q: AsRef<Path>>(from: P, to: Q) -> io::Result<()>
 /// This function will return an error in the following situations, but is not
 /// limited to just these cases:
 ///
-/// * The `from` path is not a file.
-/// * The `from` file does not exist.
-/// * The current process does not have the permission rights to access
+/// * `from` is neither a regular file nor a symlink to a regular file.
+/// * `from` does not exist.
+/// * The current process does not have the permission rights to read
 ///   `from` or write `to`.
 ///
 /// # Examples
diff --git a/library/std/src/io/buffered/linewriter.rs b/library/std/src/io/buffered/linewriter.rs
index 502c6e3c6c0..d7b620d6f91 100644
--- a/library/std/src/io/buffered/linewriter.rs
+++ b/library/std/src/io/buffered/linewriter.rs
@@ -227,6 +227,6 @@ where
                 "buffer",
                 &format_args!("{}/{}", self.inner.buffer().len(), self.inner.capacity()),
             )
-            .finish()
+            .finish_non_exhaustive()
     }
 }
diff --git a/library/std/src/io/mod.rs b/library/std/src/io/mod.rs
index 5316305a303..9953bcd556d 100644
--- a/library/std/src/io/mod.rs
+++ b/library/std/src/io/mod.rs
@@ -2114,6 +2114,7 @@ pub trait BufRead: Read {
 ///
 /// [`chain`]: Read::chain
 #[stable(feature = "rust1", since = "1.0.0")]
+#[derive(Debug)]
 pub struct Chain<T, U> {
     first: T,
     second: U,
@@ -2195,13 +2196,6 @@ impl<T, U> Chain<T, U> {
     }
 }
 
-#[stable(feature = "std_debug", since = "1.16.0")]
-impl<T: fmt::Debug, U: fmt::Debug> fmt::Debug for Chain<T, U> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Chain").field("t", &self.first).field("u", &self.second).finish()
-    }
-}
-
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: Read, U: Read> Read for Chain<T, U> {
     fn read(&mut self, buf: &mut [u8]) -> Result<usize> {
diff --git a/library/std/src/lazy.rs b/library/std/src/lazy.rs
index 974851a8bd6..ca86e569bc1 100644
--- a/library/std/src/lazy.rs
+++ b/library/std/src/lazy.rs
@@ -515,7 +515,7 @@ pub struct SyncLazy<T, F = fn() -> T> {
 #[unstable(feature = "once_cell", issue = "74465")]
 impl<T: fmt::Debug, F> fmt::Debug for SyncLazy<T, F> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Lazy").field("cell", &self.cell).field("init", &"..").finish()
+        f.debug_struct("Lazy").field("cell", &self.cell).finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
index f9cfd11e906..5690de681ca 100644
--- a/library/std/src/process.rs
+++ b/library/std/src/process.rs
@@ -234,7 +234,7 @@ impl fmt::Debug for Child {
             .field("stdin", &self.stdin)
             .field("stdout", &self.stdout)
             .field("stderr", &self.stderr)
-            .finish()
+            .finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/sync/mpsc/mod.rs b/library/std/src/sync/mpsc/mod.rs
index b12e7eeb138..c8f0a6b99fe 100644
--- a/library/std/src/sync/mpsc/mod.rs
+++ b/library/std/src/sync/mpsc/mod.rs
@@ -864,7 +864,7 @@ impl<T> Drop for Sender<T> {
 #[stable(feature = "mpsc_debug", since = "1.8.0")]
 impl<T> fmt::Debug for Sender<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Sender").finish()
+        f.debug_struct("Sender").finish_non_exhaustive()
     }
 }
 
@@ -991,7 +991,7 @@ impl<T> Drop for SyncSender<T> {
 #[stable(feature = "mpsc_debug", since = "1.8.0")]
 impl<T> fmt::Debug for SyncSender<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("SyncSender").finish()
+        f.debug_struct("SyncSender").finish_non_exhaustive()
     }
 }
 
@@ -1470,7 +1470,7 @@ impl<T> Drop for Receiver<T> {
 #[stable(feature = "mpsc_debug", since = "1.8.0")]
 impl<T> fmt::Debug for Receiver<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Receiver").finish()
+        f.debug_struct("Receiver").finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/sync/mutex.rs b/library/std/src/sync/mutex.rs
index ab61618dc7d..98c34282e0c 100644
--- a/library/std/src/sync/mutex.rs
+++ b/library/std/src/sync/mutex.rs
@@ -441,10 +441,13 @@ impl<T: ?Sized + Default> Default for Mutex<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized + fmt::Debug> fmt::Debug for Mutex<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut d = f.debug_struct("Mutex");
         match self.try_lock() {
-            Ok(guard) => f.debug_struct("Mutex").field("data", &&*guard).finish(),
+            Ok(guard) => {
+                d.field("data", &&*guard);
+            }
             Err(TryLockError::Poisoned(err)) => {
-                f.debug_struct("Mutex").field("data", &&**err.get_ref()).finish()
+                d.field("data", &&**err.get_ref());
             }
             Err(TryLockError::WouldBlock) => {
                 struct LockedPlaceholder;
@@ -453,10 +456,11 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for Mutex<T> {
                         f.write_str("<locked>")
                     }
                 }
-
-                f.debug_struct("Mutex").field("data", &LockedPlaceholder).finish()
+                d.field("data", &LockedPlaceholder);
             }
         }
+        d.field("poisoned", &self.poison.get());
+        d.finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/sync/rwlock.rs b/library/std/src/sync/rwlock.rs
index 0298f59228c..351804ec979 100644
--- a/library/std/src/sync/rwlock.rs
+++ b/library/std/src/sync/rwlock.rs
@@ -422,10 +422,13 @@ unsafe impl<#[may_dangle] T: ?Sized> Drop for RwLock<T> {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized + fmt::Debug> fmt::Debug for RwLock<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut d = f.debug_struct("RwLock");
         match self.try_read() {
-            Ok(guard) => f.debug_struct("RwLock").field("data", &&*guard).finish(),
+            Ok(guard) => {
+                d.field("data", &&*guard);
+            }
             Err(TryLockError::Poisoned(err)) => {
-                f.debug_struct("RwLock").field("data", &&**err.get_ref()).finish()
+                d.field("data", &&**err.get_ref());
             }
             Err(TryLockError::WouldBlock) => {
                 struct LockedPlaceholder;
@@ -434,10 +437,11 @@ impl<T: ?Sized + fmt::Debug> fmt::Debug for RwLock<T> {
                         f.write_str("<locked>")
                     }
                 }
-
-                f.debug_struct("RwLock").field("data", &LockedPlaceholder).finish()
+                d.field("data", &LockedPlaceholder);
             }
         }
+        d.field("poisoned", &self.poison.get());
+        d.finish_non_exhaustive()
     }
 }
 
@@ -473,7 +477,7 @@ impl<'rwlock, T: ?Sized> RwLockWriteGuard<'rwlock, T> {
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl<T: fmt::Debug> fmt::Debug for RwLockReadGuard<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RwLockReadGuard").field("lock", &self.lock).finish()
+        (**self).fmt(f)
     }
 }
 
@@ -487,7 +491,7 @@ impl<T: ?Sized + fmt::Display> fmt::Display for RwLockReadGuard<'_, T> {
 #[stable(feature = "std_debug", since = "1.16.0")]
 impl<T: fmt::Debug> fmt::Debug for RwLockWriteGuard<'_, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RwLockWriteGuard").field("lock", &self.lock).finish()
+        (**self).fmt(f)
     }
 }
 
diff --git a/library/std/src/sys/unix/process/process_unix.rs b/library/std/src/sys/unix/process/process_unix.rs
index 01f1318fe80..53916cb9abd 100644
--- a/library/std/src/sys/unix/process/process_unix.rs
+++ b/library/std/src/sys/unix/process/process_unix.rs
@@ -535,7 +535,7 @@ impl From<c_int> for ExitStatus {
 impl fmt::Display for ExitStatus {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let Some(code) = self.code() {
-            write!(f, "exit code: {}", code)
+            write!(f, "exit status: {}", code)
         } else if let Some(signal) = self.signal() {
             if self.core_dumped() {
                 write!(f, "signal: {} (core dumped)", signal)
diff --git a/library/std/src/sys/unix/process/process_unix/tests.rs b/library/std/src/sys/unix/process/process_unix/tests.rs
index 5819d2c2a5a..02c469fbcdf 100644
--- a/library/std/src/sys/unix/process/process_unix/tests.rs
+++ b/library/std/src/sys/unix/process/process_unix/tests.rs
@@ -9,8 +9,8 @@ fn exitstatus_display_tests() {
 
     t(0x0000f, "signal: 15");
     t(0x0008b, "signal: 11 (core dumped)");
-    t(0x00000, "exit code: 0");
-    t(0x0ff00, "exit code: 255");
+    t(0x00000, "exit status: 0");
+    t(0x0ff00, "exit status: 255");
 
     // On MacOS, 0x0137f is WIFCONTINUED, not WIFSTOPPED.  Probably *BSD is similar.
     //   https://github.com/rust-lang/rust/pull/82749#issuecomment-790525956
diff --git a/library/std/src/sys/wasi/fs.rs b/library/std/src/sys/wasi/fs.rs
index 1ec3ff6a10f..ed0f03e4b71 100644
--- a/library/std/src/sys/wasi/fs.rs
+++ b/library/std/src/sys/wasi/fs.rs
@@ -130,7 +130,7 @@ impl FileType {
 
 impl fmt::Debug for ReadDir {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("ReadDir").finish()
+        f.debug_struct("ReadDir").finish_non_exhaustive()
     }
 }
 
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 0ef848ff0c4..ffdf4be1584 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -1176,7 +1176,10 @@ impl Thread {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl fmt::Debug for Thread {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Thread").field("id", &self.id()).field("name", &self.name()).finish()
+        f.debug_struct("Thread")
+            .field("id", &self.id())
+            .field("name", &self.name())
+            .finish_non_exhaustive()
     }
 }