From 62e29fe25b039b89ad76a6b9a94f8085eee934d9 Mon Sep 17 00:00:00 2001
From: Martin Geisler <mgeisler@google.com>
Date: Fri, 17 May 2024 11:54:21 +0200
Subject: [PATCH 01/15] Simplify environment variable examples
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I’ve found myself visiting the documentation for `std::env::vars`
every few months, and every time I do, it is because I want to quickly
get a snippet to print out all environment variables :-)

So I think it could be nice to simplify the examples a little to make
them self-contained. It is of course a style question if one should
import a module a not, but I personally don’t import modules used just
once in a code snippet.
---
 library/std/src/env.rs | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/library/std/src/env.rs b/library/std/src/env.rs
index 6f8ac17f12c70..b3428fb23ba7f 100644
--- a/library/std/src/env.rs
+++ b/library/std/src/env.rs
@@ -120,11 +120,8 @@ pub struct VarsOs {
 /// # Examples
 ///
 /// ```
-/// use std::env;
-///
-/// // We will iterate through the references to the element returned by
-/// // env::vars();
-/// for (key, value) in env::vars() {
+/// // Print all environment variables.
+/// for (key, value) in std::env::vars() {
 ///     println!("{key}: {value}");
 /// }
 /// ```
@@ -150,11 +147,8 @@ pub fn vars() -> Vars {
 /// # Examples
 ///
 /// ```
-/// use std::env;
-///
-/// // We will iterate through the references to the element returned by
-/// // env::vars_os();
-/// for (key, value) in env::vars_os() {
+/// // Print all environment variables.
+/// for (key, value) in std::env::vars_os() {
 ///     println!("{key:?}: {value:?}");
 /// }
 /// ```

From c4391b326edbf4bcf374c9891fb0bfc2bc33531a Mon Sep 17 00:00:00 2001
From: Dion Dokter <diondokter@gmail.com>
Date: Tue, 11 Jun 2024 13:24:35 +0200
Subject: [PATCH 02/15] Skip fast path for dec2flt when optimize_for_size

---
 library/core/src/num/dec2flt/mod.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/library/core/src/num/dec2flt/mod.rs b/library/core/src/num/dec2flt/mod.rs
index a4bc8b1c9b0c3..c10bf797b57f1 100644
--- a/library/core/src/num/dec2flt/mod.rs
+++ b/library/core/src/num/dec2flt/mod.rs
@@ -250,8 +250,10 @@ pub fn dec2flt<F: RawFloat>(s: &str) -> Result<F, ParseFloatError> {
         None => return Err(pfe_invalid()),
     };
     num.negative = negative;
-    if let Some(value) = num.try_fast_path::<F>() {
-        return Ok(value);
+    if cfg!(not(feature = "optimize_for_size")) {
+        if let Some(value) = num.try_fast_path::<F>() {
+            return Ok(value);
+        }
     }
 
     // If significant digits were truncated, then we can have rounding error

From 5e2cc5793a9cf7cdbb4758ce18470dbdefd8491c Mon Sep 17 00:00:00 2001
From: Alan Egerton <eggyal@gmail.com>
Date: Tue, 9 Jul 2024 10:40:26 +0100
Subject: [PATCH 03/15] Terminate `--print link-args` output with newline

---
 compiler/rustc_codegen_ssa/src/back/link.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_codegen_ssa/src/back/link.rs b/compiler/rustc_codegen_ssa/src/back/link.rs
index 1f627353d54e1..8e07d128dbd64 100644
--- a/compiler/rustc_codegen_ssa/src/back/link.rs
+++ b/compiler/rustc_codegen_ssa/src/back/link.rs
@@ -750,7 +750,7 @@ fn link_natively(
 
     for print in &sess.opts.prints {
         if print.kind == PrintKind::LinkArgs {
-            let content = format!("{cmd:?}");
+            let content = format!("{cmd:?}\n");
             print.out.overwrite(&content, sess);
         }
     }

From f96f68f2ec4b512a91b27d1b14d3dae66305cc6e Mon Sep 17 00:00:00 2001
From: Alan Egerton <eggyal@gmail.com>
Date: Tue, 9 Jul 2024 23:07:38 +0100
Subject: [PATCH 04/15] Test that `--print link-args` ends in newline

---
 tests/run-make/link-arg/rmake.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tests/run-make/link-arg/rmake.rs b/tests/run-make/link-arg/rmake.rs
index a6d68800792f8..c0bf8d972af73 100644
--- a/tests/run-make/link-arg/rmake.rs
+++ b/tests/run-make/link-arg/rmake.rs
@@ -17,4 +17,5 @@ fn main() {
         .run_unchecked();
     out.assert_stdout_contains("lfoo");
     out.assert_stdout_contains("lbar");
+    assert!(out.stdout_utf8().ends_with('\n'));
 }

From 7f8f1780d47efa836a636de62a2b27cba20f2644 Mon Sep 17 00:00:00 2001
From: Sky <sky@sky9.dev>
Date: Sun, 7 Jul 2024 00:18:35 -0400
Subject: [PATCH 05/15] `impl Send + Sync` and override `count` for the
 `CStr::bytes` iterator

---
 library/core/src/ffi/c_str.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/library/core/src/ffi/c_str.rs b/library/core/src/ffi/c_str.rs
index d2a408485d162..1dd4710b3a36b 100644
--- a/library/core/src/ffi/c_str.rs
+++ b/library/core/src/ffi/c_str.rs
@@ -780,8 +780,15 @@ const unsafe fn const_strlen(ptr: *const c_char) -> usize {
 pub struct Bytes<'a> {
     // since we know the string is nul-terminated, we only need one pointer
     ptr: NonNull<u8>,
-    phantom: PhantomData<&'a u8>,
+    phantom: PhantomData<&'a [c_char]>,
 }
+
+#[unstable(feature = "cstr_bytes", issue = "112115")]
+unsafe impl Send for Bytes<'_> {}
+
+#[unstable(feature = "cstr_bytes", issue = "112115")]
+unsafe impl Sync for Bytes<'_> {}
+
 impl<'a> Bytes<'a> {
     #[inline]
     fn new(s: &'a CStr) -> Self {
@@ -814,7 +821,7 @@ impl Iterator for Bytes<'_> {
             if ret == 0 {
                 None
             } else {
-                self.ptr = self.ptr.offset(1);
+                self.ptr = self.ptr.add(1);
                 Some(ret)
             }
         }
@@ -824,6 +831,12 @@ impl Iterator for Bytes<'_> {
     fn size_hint(&self) -> (usize, Option<usize>) {
         if self.is_empty() { (0, Some(0)) } else { (1, None) }
     }
+
+    #[inline]
+    fn count(self) -> usize {
+        // SAFETY: We always hold a valid pointer to a C string
+        unsafe { strlen(self.ptr.as_ptr().cast()) }
+    }
 }
 
 #[unstable(feature = "cstr_bytes", issue = "112115")]

From 8dafc5c8198c65311daa9f89a61f3b5c7eb833ad Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Mon, 15 Jul 2024 20:18:56 -0700
Subject: [PATCH 06/15] std: Use read_unaligned for reading DWARF

---
 library/std/src/sys/personality/dwarf/mod.rs | 26 +++++++++-----------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/library/std/src/sys/personality/dwarf/mod.rs b/library/std/src/sys/personality/dwarf/mod.rs
index 652fbe95a14d1..281587a973296 100644
--- a/library/std/src/sys/personality/dwarf/mod.rs
+++ b/library/std/src/sys/personality/dwarf/mod.rs
@@ -17,32 +17,30 @@ pub struct DwarfReader {
     pub ptr: *const u8,
 }
 
-#[repr(C, packed)]
-struct Unaligned<T>(T);
-
+#[deny(unsafe_op_in_unsafe_fn)]
 impl DwarfReader {
     pub fn new(ptr: *const u8) -> DwarfReader {
         DwarfReader { ptr }
     }
 
-    // DWARF streams are packed, so e.g., a u32 would not necessarily be aligned
-    // on a 4-byte boundary. This may cause problems on platforms with strict
-    // alignment requirements. By wrapping data in a "packed" struct, we are
-    // telling the backend to generate "misalignment-safe" code.
+    /// Read a type T and then bump the pointer by that amount.
+    ///
+    /// DWARF streams are "packed", so all types must be read at align 1.
     pub unsafe fn read<T: Copy>(&mut self) -> T {
-        let Unaligned(result) = *(self.ptr as *const Unaligned<T>);
-        self.ptr = self.ptr.add(mem::size_of::<T>());
-        result
+        unsafe {
+            let result = self.ptr.cast::<T>().read_unaligned();
+            self.ptr = self.ptr.byte_add(mem::size_of::<T>());
+            result
+        }
     }
 
-    // ULEB128 and SLEB128 encodings are defined in Section 7.6 - "Variable
-    // Length Data".
+    /// ULEB128 and SLEB128 encodings are defined in Section 7.6 - "Variable Length Data".
     pub unsafe fn read_uleb128(&mut self) -> u64 {
         let mut shift: usize = 0;
         let mut result: u64 = 0;
         let mut byte: u8;
         loop {
-            byte = self.read::<u8>();
+            byte = unsafe { self.read::<u8>() };
             result |= ((byte & 0x7F) as u64) << shift;
             shift += 7;
             if byte & 0x80 == 0 {
@@ -57,7 +55,7 @@ impl DwarfReader {
         let mut result: u64 = 0;
         let mut byte: u8;
         loop {
-            byte = self.read::<u8>();
+            byte = unsafe { self.read::<u8>() };
             result |= ((byte & 0x7F) as u64) << shift;
             shift += 7;
             if byte & 0x80 == 0 {

From 51bdcf66d3b884134a7a3b905e3b72a365f16c40 Mon Sep 17 00:00:00 2001
From: Chris Denton <chris@chrisdenton.dev>
Date: Tue, 16 Jul 2024 10:08:26 +0000
Subject: [PATCH 07/15] Use futex.rs for Windows thread parking

---
 library/std/src/sys/pal/hermit/futex.rs       |  5 +++++
 library/std/src/sys/pal/unix/futex.rs         |  5 +++++
 library/std/src/sys/pal/wasm/atomics/futex.rs |  5 +++++
 library/std/src/sys/pal/windows/futex.rs      |  5 +++++
 library/std/src/sys/sync/mutex/futex.rs       | 21 +++++--------------
 .../std/src/sys/sync/thread_parking/futex.rs  | 17 ++++++++-------
 .../std/src/sys/sync/thread_parking/mod.rs    |  7 ++++---
 .../{windows.rs => windows7.rs}               |  0
 8 files changed, 39 insertions(+), 26 deletions(-)
 rename library/std/src/sys/sync/thread_parking/{windows.rs => windows7.rs} (100%)

diff --git a/library/std/src/sys/pal/hermit/futex.rs b/library/std/src/sys/pal/hermit/futex.rs
index b2d74d1311bcb..21c5facd52fbd 100644
--- a/library/std/src/sys/pal/hermit/futex.rs
+++ b/library/std/src/sys/pal/hermit/futex.rs
@@ -3,6 +3,11 @@ use crate::ptr::null;
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 8-bits but may be larger.
+pub type SmallAtomic = AtomicU32;
+/// Must be the underlying type of SmallAtomic
+pub type SmallPrimitive = u32;
+
 pub fn futex_wait(futex: &AtomicU32, expected: u32, timeout: Option<Duration>) -> bool {
     // Calculate the timeout as a relative timespec.
     //
diff --git a/library/std/src/sys/pal/unix/futex.rs b/library/std/src/sys/pal/unix/futex.rs
index 26161a9af79d8..b8900da4cddb5 100644
--- a/library/std/src/sys/pal/unix/futex.rs
+++ b/library/std/src/sys/pal/unix/futex.rs
@@ -11,6 +11,11 @@
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 8-bits but may be larger.
+pub type SmallAtomic = AtomicU32;
+/// Must be the underlying type of SmallAtomic
+pub type SmallPrimitive = u32;
+
 /// Wait for a futex_wake operation to wake us.
 ///
 /// Returns directly if the futex doesn't hold the expected value.
diff --git a/library/std/src/sys/pal/wasm/atomics/futex.rs b/library/std/src/sys/pal/wasm/atomics/futex.rs
index a21b71efbbc69..3584138ca0447 100644
--- a/library/std/src/sys/pal/wasm/atomics/futex.rs
+++ b/library/std/src/sys/pal/wasm/atomics/futex.rs
@@ -6,6 +6,11 @@ use core::arch::wasm64 as wasm;
 use crate::sync::atomic::AtomicU32;
 use crate::time::Duration;
 
+/// An atomic for use as a futex that is at least 8-bits but may be larger.
+pub type SmallAtomic = AtomicU32;
+/// Must be the underlying type of SmallAtomic
+pub type SmallPrimitive = u32;
+
 /// Wait for a futex_wake operation to wake us.
 ///
 /// Returns directly if the futex doesn't hold the expected value.
diff --git a/library/std/src/sys/pal/windows/futex.rs b/library/std/src/sys/pal/windows/futex.rs
index 08b7fe300dc3c..cb802fdd9c96d 100644
--- a/library/std/src/sys/pal/windows/futex.rs
+++ b/library/std/src/sys/pal/windows/futex.rs
@@ -10,6 +10,11 @@ use core::sync::atomic::{
 };
 use core::time::Duration;
 
+/// An atomic for use as a futex that is at least 8-bits but may be larger.
+pub type SmallAtomic = AtomicU8;
+/// Must be the underlying type of SmallAtomic
+pub type SmallPrimitive = u8;
+
 pub unsafe trait Waitable {
     type Atomic;
 }
diff --git a/library/std/src/sys/sync/mutex/futex.rs b/library/std/src/sys/sync/mutex/futex.rs
index 7427cae94d68a..81afa94b14787 100644
--- a/library/std/src/sys/sync/mutex/futex.rs
+++ b/library/std/src/sys/sync/mutex/futex.rs
@@ -1,19 +1,8 @@
-use crate::sync::atomic::{
-    self,
-    Ordering::{Acquire, Relaxed, Release},
-};
-use crate::sys::futex::{futex_wait, futex_wake};
-
-cfg_if::cfg_if! {
-if #[cfg(windows)] {
-    // On Windows we can have a smol futex
-    type Atomic = atomic::AtomicU8;
-    type State = u8;
-} else {
-    type Atomic = atomic::AtomicU32;
-    type State = u32;
-}
-}
+use crate::sync::atomic::Ordering::{Acquire, Relaxed, Release};
+use crate::sys::futex::{self, futex_wait, futex_wake};
+
+type Atomic = futex::SmallAtomic;
+type State = futex::SmallPrimitive;
 
 pub struct Mutex {
     futex: Atomic,
diff --git a/library/std/src/sys/sync/thread_parking/futex.rs b/library/std/src/sys/sync/thread_parking/futex.rs
index 588e7b27826f6..034eececb2a28 100644
--- a/library/std/src/sys/sync/thread_parking/futex.rs
+++ b/library/std/src/sys/sync/thread_parking/futex.rs
@@ -1,15 +1,18 @@
+#![forbid(unsafe_op_in_unsafe_fn)]
 use crate::pin::Pin;
-use crate::sync::atomic::AtomicU32;
 use crate::sync::atomic::Ordering::{Acquire, Release};
-use crate::sys::futex::{futex_wait, futex_wake};
+use crate::sys::futex::{self, futex_wait, futex_wake};
 use crate::time::Duration;
 
-const PARKED: u32 = u32::MAX;
-const EMPTY: u32 = 0;
-const NOTIFIED: u32 = 1;
+type Atomic = futex::SmallAtomic;
+type State = futex::SmallPrimitive;
+
+const PARKED: State = State::MAX;
+const EMPTY: State = 0;
+const NOTIFIED: State = 1;
 
 pub struct Parker {
-    state: AtomicU32,
+    state: Atomic,
 }
 
 // Notes about memory ordering:
@@ -36,7 +39,7 @@ impl Parker {
     /// Construct the futex parker. The UNIX parker implementation
     /// requires this to happen in-place.
     pub unsafe fn new_in_place(parker: *mut Parker) {
-        parker.write(Self { state: AtomicU32::new(EMPTY) });
+        unsafe { parker.write(Self { state: Atomic::new(EMPTY) }) };
     }
 
     // Assumes this is only called by the thread that owns the Parker,
diff --git a/library/std/src/sys/sync/thread_parking/mod.rs b/library/std/src/sys/sync/thread_parking/mod.rs
index ed1a6437faaaf..0ebc5e093ee2a 100644
--- a/library/std/src/sys/sync/thread_parking/mod.rs
+++ b/library/std/src/sys/sync/thread_parking/mod.rs
@@ -1,5 +1,6 @@
 cfg_if::cfg_if! {
     if #[cfg(any(
+        all(target_os = "windows", not(target_vendor = "win7")),
         target_os = "linux",
         target_os = "android",
         all(target_arch = "wasm32", target_feature = "atomics"),
@@ -18,9 +19,9 @@ cfg_if::cfg_if! {
     ))] {
         mod id;
         pub use id::Parker;
-    } else if #[cfg(target_os = "windows")] {
-        mod windows;
-        pub use windows::Parker;
+    } else if #[cfg(target_vendor = "win7")] {
+        mod windows7;
+        pub use windows7::Parker;
     } else if #[cfg(all(target_vendor = "apple", not(miri)))] {
         mod darwin;
         pub use darwin::Parker;
diff --git a/library/std/src/sys/sync/thread_parking/windows.rs b/library/std/src/sys/sync/thread_parking/windows7.rs
similarity index 100%
rename from library/std/src/sys/sync/thread_parking/windows.rs
rename to library/std/src/sys/sync/thread_parking/windows7.rs

From 249905780f8313898fd239e71b32bbbc42cd5137 Mon Sep 17 00:00:00 2001
From: Jubilee <46493976+workingjubilee@users.noreply.github.com>
Date: Tue, 16 Jul 2024 12:51:14 -0700
Subject: [PATCH 08/15] std: unwrapped unsafe is VERBOTEN!
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: Jonas Böttiger <jonasboettiger@icloud.com>
---
 library/std/src/sys/personality/dwarf/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/std/src/sys/personality/dwarf/mod.rs b/library/std/src/sys/personality/dwarf/mod.rs
index 281587a973296..89f7f133e21b4 100644
--- a/library/std/src/sys/personality/dwarf/mod.rs
+++ b/library/std/src/sys/personality/dwarf/mod.rs
@@ -17,7 +17,7 @@ pub struct DwarfReader {
     pub ptr: *const u8,
 }
 
-#[deny(unsafe_op_in_unsafe_fn)]
+#[forbid(unsafe_op_in_unsafe_fn)]
 impl DwarfReader {
     pub fn new(ptr: *const u8) -> DwarfReader {
         DwarfReader { ptr }

From d9fde2504a1e77765e9505d2346a15867ad5a4b8 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Thu, 20 Jun 2024 19:55:38 +1000
Subject: [PATCH 09/15] Merge some `core::iter` entries.

---
 library/core/src/prelude/common.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/library/core/src/prelude/common.rs b/library/core/src/prelude/common.rs
index a6a1a055e2983..bdaa16613544a 100644
--- a/library/core/src/prelude/common.rs
+++ b/library/core/src/prelude/common.rs
@@ -33,10 +33,7 @@ pub use crate::convert::{AsMut, AsRef, From, Into};
 pub use crate::default::Default;
 #[stable(feature = "core_prelude", since = "1.4.0")]
 #[doc(no_inline)]
-pub use crate::iter::{DoubleEndedIterator, ExactSizeIterator};
-#[stable(feature = "core_prelude", since = "1.4.0")]
-#[doc(no_inline)]
-pub use crate::iter::{Extend, IntoIterator, Iterator};
+pub use crate::iter::{DoubleEndedIterator, ExactSizeIterator, Extend, IntoIterator, Iterator};
 #[stable(feature = "core_prelude", since = "1.4.0")]
 #[doc(no_inline)]
 pub use crate::option::Option::{self, None, Some};

From 75b6ec980059292faa9cdf538b552faf6b70fb29 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Thu, 20 Jun 2024 15:44:13 +1000
Subject: [PATCH 10/15] Avoid comments that describe multiple `use` items.

There are some comments describing multiple subsequent `use` items. When
the big `use` reformatting happens some of these `use` items will be
reordered, possibly moving them away from the comment. With this
additional level of formatting it's not really feasible to have comments
of this type. This commit removes them in various ways:

- merging separate `use` items when appropriate;

- inserting blank lines between the comment and the first `use` item;

- outright deletion (for comments that are relatively low-value);

- adding a separate "top-level" comment.

We also entirely skip formatting for four library files that contain
nothing but `pub use` re-exports, where reordering would be painful.
---
 .../src/interpret/validity.rs                 |  1 -
 compiler/rustc_lint/src/lib.rs                |  1 -
 compiler/rustc_pattern_analysis/src/lib.rs    |  4 +--
 .../rustc_smir/src/rustc_internal/internal.rs |  1 +
 library/core/src/char/mod.rs                  |  6 ++---
 library/core/src/prelude/common.rs            |  3 +++
 library/core/src/prelude/mod.rs               |  3 +++
 library/core/src/ptr/mod.rs                   |  5 ++--
 library/core/src/unicode/mod.rs               | 26 +++++++++----------
 library/std/src/lib.rs                        |  1 -
 library/std/src/os/fortanix_sgx/mod.rs        |  1 -
 library/std/src/prelude/common.rs             |  3 +++
 library/std/src/prelude/mod.rs                |  3 +++
 library/std/src/rt.rs                         |  1 -
 library/std/src/sys/pal/wasi/mod.rs           |  9 ++++---
 library/std/src/sys/pal/wasip2/mod.rs         |  9 ++++---
 library/test/src/lib.rs                       |  1 -
 17 files changed, 43 insertions(+), 35 deletions(-)

diff --git a/compiler/rustc_const_eval/src/interpret/validity.rs b/compiler/rustc_const_eval/src/interpret/validity.rs
index 7fea061766666..4da7e233889f0 100644
--- a/compiler/rustc_const_eval/src/interpret/validity.rs
+++ b/compiler/rustc_const_eval/src/interpret/validity.rs
@@ -34,7 +34,6 @@ use super::{
     Pointer, Projectable, Scalar, ValueVisitor,
 };
 
-// for the validation errors
 use super::InterpError::UndefinedBehavior as Ub;
 use super::InterpError::Unsupported as Unsup;
 use super::UndefinedBehaviorInfo::*;
diff --git a/compiler/rustc_lint/src/lib.rs b/compiler/rustc_lint/src/lib.rs
index 8be8996e4c8f0..4e83ef0c6291b 100644
--- a/compiler/rustc_lint/src/lib.rs
+++ b/compiler/rustc_lint/src/lib.rs
@@ -120,7 +120,6 @@ use types::*;
 use unit_bindings::*;
 use unused::*;
 
-/// Useful for other parts of the compiler / Clippy.
 pub use builtin::{MissingDoc, SoftLints};
 pub use context::{CheckLintNameResult, FindLintError, LintStore};
 pub use context::{EarlyContext, LateContext, LintContext};
diff --git a/compiler/rustc_pattern_analysis/src/lib.rs b/compiler/rustc_pattern_analysis/src/lib.rs
index c9590ad06b05d..1b4bcb789d2da 100644
--- a/compiler/rustc_pattern_analysis/src/lib.rs
+++ b/compiler/rustc_pattern_analysis/src/lib.rs
@@ -21,9 +21,7 @@ rustc_fluent_macro::fluent_messages! { "../messages.ftl" }
 
 use std::fmt;
 
-// Re-exports to avoid rustc_index version issues.
-pub use rustc_index::Idx;
-pub use rustc_index::IndexVec;
+pub use rustc_index::{Idx, IndexVec}; // re-exported to avoid rustc_index version issues
 
 #[cfg(feature = "rustc")]
 use rustc_middle::ty::Ty;
diff --git a/compiler/rustc_smir/src/rustc_internal/internal.rs b/compiler/rustc_smir/src/rustc_internal/internal.rs
index 7c3553b60fddb..854295dc04818 100644
--- a/compiler/rustc_smir/src/rustc_internal/internal.rs
+++ b/compiler/rustc_smir/src/rustc_internal/internal.rs
@@ -4,6 +4,7 @@
 //! due to incomplete stable coverage.
 
 // Prefer importing stable_mir over internal rustc constructs to make this file more readable.
+
 use crate::rustc_smir::Tables;
 use rustc_middle::ty::{self as rustc_ty, Const as InternalConst, Ty as InternalTy, TyCtxt};
 use rustc_span::Symbol;
diff --git a/library/core/src/char/mod.rs b/library/core/src/char/mod.rs
index 26b463e25ea62..3c641a2e01c93 100644
--- a/library/core/src/char/mod.rs
+++ b/library/core/src/char/mod.rs
@@ -24,7 +24,6 @@ mod convert;
 mod decode;
 mod methods;
 
-// stable re-exports
 #[stable(feature = "try_from", since = "1.34.0")]
 pub use self::convert::CharTryFromError;
 #[stable(feature = "char_from_str", since = "1.20.0")]
@@ -32,11 +31,10 @@ pub use self::convert::ParseCharError;
 #[stable(feature = "decode_utf16", since = "1.9.0")]
 pub use self::decode::{DecodeUtf16, DecodeUtf16Error};
 
-// perma-unstable re-exports
 #[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")]
-pub use self::methods::encode_utf16_raw;
+pub use self::methods::encode_utf16_raw; // perma-unstable
 #[unstable(feature = "char_internals", reason = "exposed only for libstd", issue = "none")]
-pub use self::methods::encode_utf8_raw;
+pub use self::methods::encode_utf8_raw; // perma-unstable
 
 use crate::ascii;
 use crate::error::Error;
diff --git a/library/core/src/prelude/common.rs b/library/core/src/prelude/common.rs
index bdaa16613544a..e38ef1e147c76 100644
--- a/library/core/src/prelude/common.rs
+++ b/library/core/src/prelude/common.rs
@@ -2,6 +2,9 @@
 //!
 //! See the [module-level documentation](super) for more.
 
+// No formatting: this file is nothing but re-exports, and their order is worth preserving.
+#![cfg_attr(rustfmt, rustfmt::skip)]
+
 // Re-exported core operators
 #[stable(feature = "core_prelude", since = "1.4.0")]
 #[doc(no_inline)]
diff --git a/library/core/src/prelude/mod.rs b/library/core/src/prelude/mod.rs
index ca33ef160e88b..496b78439ea6c 100644
--- a/library/core/src/prelude/mod.rs
+++ b/library/core/src/prelude/mod.rs
@@ -4,6 +4,9 @@
 //! This module is imported by default when `#![no_std]` is used in the same
 //! manner as the standard library's prelude.
 
+// No formatting: this file is nothing but re-exports, and their order is worth preserving.
+#![cfg_attr(rustfmt, rustfmt::skip)]
+
 #![stable(feature = "core_prelude", since = "1.4.0")]
 
 mod common;
diff --git a/library/core/src/ptr/mod.rs b/library/core/src/ptr/mod.rs
index a8a47b69632f7..f2247e83ec5c5 100644
--- a/library/core/src/ptr/mod.rs
+++ b/library/core/src/ptr/mod.rs
@@ -1809,10 +1809,9 @@ pub(crate) const unsafe fn align_offset<T: Sized>(p: *const T, a: usize) -> usiz
     // FIXME(#75598): Direct use of these intrinsics improves codegen significantly at opt-level <=
     // 1, where the method versions of these operations are not inlined.
     use intrinsics::{
-        assume, cttz_nonzero, exact_div, mul_with_overflow, unchecked_rem, unchecked_sub,
-        wrapping_add, wrapping_mul, wrapping_sub,
+        assume, cttz_nonzero, exact_div, mul_with_overflow, unchecked_rem, unchecked_shl,
+        unchecked_shr, unchecked_sub, wrapping_add, wrapping_mul, wrapping_sub,
     };
-    use intrinsics::{unchecked_shl, unchecked_shr};
 
     /// Calculate multiplicative modular inverse of `x` modulo `m`.
     ///
diff --git a/library/core/src/unicode/mod.rs b/library/core/src/unicode/mod.rs
index e1faa407d54c5..5ddd9f7476dd8 100644
--- a/library/core/src/unicode/mod.rs
+++ b/library/core/src/unicode/mod.rs
@@ -1,6 +1,19 @@
 #![unstable(feature = "unicode_internals", issue = "none")]
 #![allow(missing_docs)]
 
+// The `pub use` ones are for use in alloc, and are not re-exported in std.
+
+pub(crate) use unicode_data::alphabetic::lookup as Alphabetic;
+pub use unicode_data::case_ignorable::lookup as Case_Ignorable;
+pub use unicode_data::cased::lookup as Cased;
+pub(crate) use unicode_data::cc::lookup as Cc;
+pub use unicode_data::conversions;
+pub(crate) use unicode_data::grapheme_extend::lookup as Grapheme_Extend;
+pub(crate) use unicode_data::lowercase::lookup as Lowercase;
+pub(crate) use unicode_data::n::lookup as N;
+pub(crate) use unicode_data::uppercase::lookup as Uppercase;
+pub(crate) use unicode_data::white_space::lookup as White_Space;
+
 pub(crate) mod printable;
 mod unicode_data;
 
@@ -16,16 +29,3 @@ mod unicode_data;
 /// [Unicode 11.0 or later, Section 3.1 Versions of the Unicode Standard](https://www.unicode.org/versions/Unicode11.0.0/ch03.pdf#page=4).
 #[stable(feature = "unicode_version", since = "1.45.0")]
 pub const UNICODE_VERSION: (u8, u8, u8) = unicode_data::UNICODE_VERSION;
-
-// For use in alloc, not re-exported in std.
-pub use unicode_data::{
-    case_ignorable::lookup as Case_Ignorable, cased::lookup as Cased, conversions,
-};
-
-pub(crate) use unicode_data::alphabetic::lookup as Alphabetic;
-pub(crate) use unicode_data::cc::lookup as Cc;
-pub(crate) use unicode_data::grapheme_extend::lookup as Grapheme_Extend;
-pub(crate) use unicode_data::lowercase::lookup as Lowercase;
-pub(crate) use unicode_data::n::lookup as N;
-pub(crate) use unicode_data::uppercase::lookup as Uppercase;
-pub(crate) use unicode_data::white_space::lookup as White_Space;
diff --git a/library/std/src/lib.rs b/library/std/src/lib.rs
index 66aeb35aceec0..b11670d88c277 100644
--- a/library/std/src/lib.rs
+++ b/library/std/src/lib.rs
@@ -469,7 +469,6 @@ pub mod rt;
 // The Rust prelude
 pub mod prelude;
 
-// Public module declarations and re-exports
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use alloc_crate::borrow;
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/library/std/src/os/fortanix_sgx/mod.rs b/library/std/src/os/fortanix_sgx/mod.rs
index 39a42f4e17fec..b31dc06f8dfbd 100644
--- a/library/std/src/os/fortanix_sgx/mod.rs
+++ b/library/std/src/os/fortanix_sgx/mod.rs
@@ -28,7 +28,6 @@ pub mod usercalls {
         pub use crate::sys::abi::usercalls::raw::{do_usercall, Usercalls as UsercallNrs};
         pub use crate::sys::abi::usercalls::raw::{Register, RegisterArgument, ReturnValue};
 
-        // fortanix-sgx-abi re-exports
         pub use crate::sys::abi::usercalls::raw::Error;
         pub use crate::sys::abi::usercalls::raw::{
             ByteBuffer, Cancel, FifoDescriptor, Return, Usercall,
diff --git a/library/std/src/prelude/common.rs b/library/std/src/prelude/common.rs
index 055ab7eb6d987..b231bd871b3b4 100644
--- a/library/std/src/prelude/common.rs
+++ b/library/std/src/prelude/common.rs
@@ -2,6 +2,9 @@
 //!
 //! See the [module-level documentation](super) for more.
 
+// No formatting: this file is nothing but re-exports, and their order is worth preserving.
+#![cfg_attr(rustfmt, rustfmt::skip)]
+
 // Re-exported core operators
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
diff --git a/library/std/src/prelude/mod.rs b/library/std/src/prelude/mod.rs
index 2d4639342bf85..0c610ba67e65c 100644
--- a/library/std/src/prelude/mod.rs
+++ b/library/std/src/prelude/mod.rs
@@ -95,6 +95,9 @@
 //! [book-enums]: ../../book/ch06-01-defining-an-enum.html
 //! [book-iter]: ../../book/ch13-02-iterators.html
 
+// No formatting: this file is nothing but re-exports, and their order is worth preserving.
+#![cfg_attr(rustfmt, rustfmt::skip)]
+
 #![stable(feature = "rust1", since = "1.0.0")]
 
 mod common;
diff --git a/library/std/src/rt.rs b/library/std/src/rt.rs
index c0a1c5f5594ae..82ededa58001a 100644
--- a/library/std/src/rt.rs
+++ b/library/std/src/rt.rs
@@ -16,7 +16,6 @@
 #![deny(unsafe_op_in_unsafe_fn)]
 #![allow(unused_macros)]
 
-// Re-export some of our utilities which are expected by other crates.
 pub use crate::panicking::{begin_panic, panic_count};
 pub use core::panicking::{panic_display, panic_fmt};
 
diff --git a/library/std/src/sys/pal/wasi/mod.rs b/library/std/src/sys/pal/wasi/mod.rs
index 8dfb733043e77..d8fe06d1973c9 100644
--- a/library/std/src/sys/pal/wasi/mod.rs
+++ b/library/std/src/sys/pal/wasi/mod.rs
@@ -39,12 +39,15 @@ pub mod time;
 #[deny(unsafe_op_in_unsafe_fn)]
 #[allow(unused)]
 mod common;
+
 pub use common::*;
 
 mod helpers;
-// These exports are listed individually to work around Rust's glob import
-// conflict rules. If we glob export `helpers` and `common` together, then
-// the compiler complains about conflicts.
+
+// The following exports are listed individually to work around Rust's glob
+// import conflict rules. If we glob export `helpers` and `common` together,
+// then the compiler complains about conflicts.
+
 pub use helpers::abort_internal;
 pub use helpers::decode_error_kind;
 use helpers::err2io;
diff --git a/library/std/src/sys/pal/wasip2/mod.rs b/library/std/src/sys/pal/wasip2/mod.rs
index 7af0917b8ed42..0930d2e22fa8d 100644
--- a/library/std/src/sys/pal/wasip2/mod.rs
+++ b/library/std/src/sys/pal/wasip2/mod.rs
@@ -41,13 +41,16 @@ pub mod time;
 #[deny(unsafe_op_in_unsafe_fn)]
 #[allow(unused)]
 mod common;
+
 pub use common::*;
 
 #[path = "../wasi/helpers.rs"]
 mod helpers;
-// These exports are listed individually to work around Rust's glob import
-// conflict rules. If we glob export `helpers` and `common` together, then
-// the compiler complains about conflicts.
+
+// The following exports are listed individually to work around Rust's glob
+// import conflict rules. If we glob export `helpers` and `common` together,
+// then the compiler complains about conflicts.
+
 pub use helpers::abort_internal;
 pub use helpers::decode_error_kind;
 use helpers::err2io;
diff --git a/library/test/src/lib.rs b/library/test/src/lib.rs
index 7aff7fe1fdd68..71cb796b93705 100644
--- a/library/test/src/lib.rs
+++ b/library/test/src/lib.rs
@@ -25,7 +25,6 @@
 #![feature(test)]
 #![allow(internal_features)]
 
-// Public reexports
 pub use self::bench::{black_box, Bencher};
 pub use self::console::run_tests_console;
 pub use self::options::{ColorConfig, Options, OutputFormat, RunIgnored, ShouldPanic};

From 7f0ccfe69d7c79ed84a7fb23081fd2d15434da62 Mon Sep 17 00:00:00 2001
From: Nicholas Nethercote <n.nethercote@gmail.com>
Date: Thu, 20 Jun 2024 20:10:25 +1000
Subject: [PATCH 11/15] Adjust some comments on individual `use` declarations.

When we do the big `use` reformatting there are a tiny number of cases
where rustfmt moves a comment from one `use` item to another in an
undesirable way. This commit pre-emptively rearranges things to prevent
this from happening.
---
 library/alloc/src/testing/crash_test.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/library/alloc/src/testing/crash_test.rs b/library/alloc/src/testing/crash_test.rs
index bcf5f5f72510e..ff72f99b2cbed 100644
--- a/library/alloc/src/testing/crash_test.rs
+++ b/library/alloc/src/testing/crash_test.rs
@@ -1,5 +1,4 @@
-// We avoid relying on anything else in the crate, apart from the `Debug` trait.
-use crate::fmt::Debug;
+use crate::fmt::Debug; // the `Debug` trait is the only thing we use from `crate::fmt`
 use std::cmp::Ordering;
 use std::sync::atomic::{AtomicUsize, Ordering::SeqCst};
 

From e48d33e18a1b34d2d66fa1f917d639cef4f63a18 Mon Sep 17 00:00:00 2001
From: Erik Kaneda <erik@risczero.com>
Date: Tue, 16 Jul 2024 14:35:00 -0700
Subject: [PATCH 12/15] zkvm: add `#[forbid(unsafe_op_in_unsafe_fn)]` in
 `stdlib`

This also adds an additional `unsafe` block to address compiler errors.
---
 library/std/src/sys/pal/zkvm/alloc.rs | 2 +-
 library/std/src/sys/pal/zkvm/mod.rs   | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/std/src/sys/pal/zkvm/alloc.rs b/library/std/src/sys/pal/zkvm/alloc.rs
index fd333f1215150..2fdca22352470 100644
--- a/library/std/src/sys/pal/zkvm/alloc.rs
+++ b/library/std/src/sys/pal/zkvm/alloc.rs
@@ -5,7 +5,7 @@ use crate::alloc::{GlobalAlloc, Layout, System};
 unsafe impl GlobalAlloc for System {
     #[inline]
     unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
-        abi::sys_alloc_aligned(layout.size(), layout.align())
+        unsafe { abi::sys_alloc_aligned(layout.size(), layout.align()) }
     }
 
     #[inline]
diff --git a/library/std/src/sys/pal/zkvm/mod.rs b/library/std/src/sys/pal/zkvm/mod.rs
index bacde9d880c2c..651f25d66236b 100644
--- a/library/std/src/sys/pal/zkvm/mod.rs
+++ b/library/std/src/sys/pal/zkvm/mod.rs
@@ -6,6 +6,7 @@
 //! This is all super highly experimental and not actually intended for
 //! wide/production use yet, it's still all in the experimental category. This
 //! will likely change over time.
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 const WORD_SIZE: usize = core::mem::size_of::<u32>();
 

From b5a83a6f718f7e56a403088b94e8df1bbe20169a Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Tue, 16 Jul 2024 16:14:21 -0700
Subject: [PATCH 13/15] xous: Forbid unwrapped unsafe in platform modules

---
 library/std/src/os/xous/mod.rs      | 1 +
 library/std/src/sys/pal/xous/mod.rs | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/library/std/src/os/xous/mod.rs b/library/std/src/os/xous/mod.rs
index 153694a89a78d..4b21695c4ac7e 100644
--- a/library/std/src/os/xous/mod.rs
+++ b/library/std/src/os/xous/mod.rs
@@ -1,5 +1,6 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 #![doc(cfg(target_os = "xous"))]
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 pub mod ffi;
 
diff --git a/library/std/src/sys/pal/xous/mod.rs b/library/std/src/sys/pal/xous/mod.rs
index a28a52e305e22..961d45c5e834f 100644
--- a/library/std/src/sys/pal/xous/mod.rs
+++ b/library/std/src/sys/pal/xous/mod.rs
@@ -1,4 +1,4 @@
-#![deny(unsafe_op_in_unsafe_fn)]
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 pub mod alloc;
 #[path = "../unsupported/args.rs"]

From 33f1d9d554dad10ebc11453d1595c97dba72d211 Mon Sep 17 00:00:00 2001
From: Dion Dokter <diondokter@gmail.com>
Date: Wed, 17 Jul 2024 01:20:56 +0200
Subject: [PATCH 14/15] Cfg nit

Co-authored-by: Clar Fon <15850505+clarfonthey@users.noreply.github.com>
---
 library/core/src/num/dec2flt/mod.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/core/src/num/dec2flt/mod.rs b/library/core/src/num/dec2flt/mod.rs
index c10bf797b57f1..9aac2332dce0d 100644
--- a/library/core/src/num/dec2flt/mod.rs
+++ b/library/core/src/num/dec2flt/mod.rs
@@ -250,7 +250,7 @@ pub fn dec2flt<F: RawFloat>(s: &str) -> Result<F, ParseFloatError> {
         None => return Err(pfe_invalid()),
     };
     num.negative = negative;
-    if cfg!(not(feature = "optimize_for_size")) {
+    if !cfg!(feature = "optimize_for_size") {
         if let Some(value) = num.try_fast_path::<F>() {
             return Ok(value);
         }

From 586ef83f3f589e4d1eab7895982b9e7cee827fce Mon Sep 17 00:00:00 2001
From: Jubilee Young <workingjubilee@gmail.com>
Date: Tue, 16 Jul 2024 16:17:38 -0700
Subject: [PATCH 15/15] uefi: Forbid unwrapped unsafe in platform modules

---
 library/std/src/os/uefi/mod.rs      | 1 +
 library/std/src/sys/pal/uefi/mod.rs | 1 +
 2 files changed, 2 insertions(+)

diff --git a/library/std/src/os/uefi/mod.rs b/library/std/src/os/uefi/mod.rs
index 8ef05eee1f4e7..b42d796b28f69 100644
--- a/library/std/src/os/uefi/mod.rs
+++ b/library/std/src/os/uefi/mod.rs
@@ -2,6 +2,7 @@
 
 #![unstable(feature = "uefi_std", issue = "100499")]
 #![doc(cfg(target_os = "uefi"))]
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 pub mod env;
 #[path = "../windows/ffi.rs"]
diff --git a/library/std/src/sys/pal/uefi/mod.rs b/library/std/src/sys/pal/uefi/mod.rs
index 408031a461665..4d50d9e8c3d9c 100644
--- a/library/std/src/sys/pal/uefi/mod.rs
+++ b/library/std/src/sys/pal/uefi/mod.rs
@@ -11,6 +11,7 @@
 //!
 //! [`OsStr`]: crate::ffi::OsStr
 //! [`OsString`]: crate::ffi::OsString
+#![forbid(unsafe_op_in_unsafe_fn)]
 
 pub mod alloc;
 pub mod args;