Rollup of 9 pull requests

.mailmap

@@ -9,7 +9,7 @@ Aaron Todd <github@opprobrio.us>
 Abhishek Chanda <abhishek.becs@gmail.com> Abhishek Chanda <abhishek@cloudscaling.com>
 Abhijeet Bhagat <abhijeet.bhagat@gmx.com>
 Abroskin Alexander <arkweid@evilmartians.com>
-Adolfo Ochagavía <aochagavia92@gmail.com>
+Adolfo Ochagavía <aochagavia92@gmail.com> <github@adolfo.ochagavia.xyz>
 Adrian Heine né Lang <mail@adrianheine.de>
 Adrien Tétar <adri-from-59@hotmail.fr>
 Ahmed Charles <ahmedcharles@gmail.com> <acharles@outlook.com>
@@ -36,6 +36,7 @@ Amanda Stjerna <mail@amandastjerna.se> <albin.stjerna@gmail.com>
 Amanda Stjerna <mail@amandastjerna.se> <amanda.stjerna@it.uu.se>
 Amanieu d'Antras <amanieu@gmail.com> <amanieu.dantras@huawei.com>
 Amos Onn <amosonn@gmail.com>
+Amos Wenger <amoswenger@gmail.com> <fasterthanlime@users.noreply.github.com>
 Ana-Maria Mihalache <mihalacheana.maria@yahoo.com>
 Anatoly Ikorsky <aikorsky@gmail.com>
 Andre Bogus <bogusandre@gmail.com>
@@ -276,7 +277,8 @@ Irina Popa <irinagpopa@gmail.com>
 Ivan Ivaschenko <defuz.net@gmail.com>
 ivan tkachenko <me@ratijas.tk>
 J. J. Weber <jjweber@gmail.com>
-Jack Huey <jack.huey@umassmed.edu> <jackh726@gmail.com>
+Jack Huey <jackh726@gmail.com> <jack.huey@umassmed.edu>
+Jack Huey <jackh726@gmail.com> <31162821+jackh726@users.noreply.github.com>
 Jacob <jacob.macritchie@gmail.com>
 Jacob Hoffman-Andrews <rust@hoffman-andrews.com> <github@hoffman-andrews.com>
 Jacob Greenfield <xales@naveria.com>
@@ -292,6 +294,8 @@ Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakub.bukaj@yahoo.com>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakub@jakub.cc>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakubw@jakubw.net>
+Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <ja.wieczorek@student.uw.edu.pl>
+Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <software@jacobadam.net>
 Jakub Beránek <berykubik@gmail.com> <jakub.beranek@vsb.cz>
 James [Undefined] <tpzker@thepuzzlemaker.info>
 James Deng <cnjamesdeng@gmail.com> <cnJamesDeng@gmail.com>
@@ -303,6 +307,7 @@ Jamie Hill-Daniel <jamie@hill-daniel.co.uk> <clubby789@gmail.com>
 Jana Dönszelmann <jana@donsz.nl>
 Jana Dönszelmann <jana@donsz.nl> <jonathan@donsz.nl>
 Jana Dönszelmann <jana@donsz.nl> <jonabent@gmail.com>
+Jane Lusby <jlusby42@gmail.com> <jlusby@yaah.dev>
 Jan-Erik Rediger <janerik@fnordig.de> <badboy@archlinux.us>
 Jaro Fietz <jaro.fietz@gmx.de>
 Jason Fager <jfager@gmail.com>
@@ -313,6 +318,7 @@ Jason Toffaletti <toffaletti@gmail.com> Jason Toffaletti <jason@topsy.com>
 Jauhien Piatlicki <jauhien@gentoo.org> Jauhien Piatlicki <jpiatlicki@zertisa.com>
 Jay True <glacjay@gmail.com>
 Jeremy Letang <letang.jeremy@gmail.com>
+Jeremy Soller <jackpot51@gmail.com> <jeremy@system76.com>
 Jeremy Sorensen <jeremy.a.sorensen@gmail.com>
 Jeremy Stucki <dev@jeremystucki.ch> <stucki.jeremy@gmail.com>
 Jeremy Stucki <dev@jeremystucki.ch> <jeremy@myelin.ch>
@@ -336,6 +342,7 @@ John Kåre Alsaker <john.kare.alsaker@gmail.com>
 John Kåre Alsaker <john.kare.alsaker@gmail.com> <zoxc32@gmail.com>
 John Talling <inrustwetrust@users.noreply.github.com>
 John Van Enk <vanenkj@gmail.com>
+Jon Gjengset <jon@thesquareplanet.com> <jongje@amazon.com>
 Jonas Tepe <jonasprogrammer@gmail.com>
 Jonathan Bailey <jbailey@mozilla.com> <jbailey@jbailey-20809.local>
 Jonathan Chan Kwan Yin <sofe2038@gmail.com>
@@ -424,7 +431,7 @@ Malo Jaffré <jaffre.malo@gmail.com>
 Manish Goregaokar <manishsmail@gmail.com>
 Mara Bos <m-ou.se@m-ou.se>
 Marcell Pardavi <marcell.pardavi@gmail.com>
-Marco Ieni <11428655+MarcoIeni@users.noreply.github.com>
+Marco Ieni <marcoieni@rustfoundation.org> <11428655+MarcoIeni@users.noreply.github.com>
 Marcus Klaas de Vries <mail@marcusklaas.nl>
 Margaret Meyerhofer <mmeyerho@andrew.cmu.edu> <mmeyerho@andrew>
 Marijn Schouten <mhkbst@gmail.com> <hkBst@users.noreply.github.com>
@@ -531,6 +538,7 @@ Oliver Scherer <oli-obk@users.noreply.github.com> <oliver.schneider@kit.edu>
 Oliver Scherer <oli-obk@users.noreply.github.com> <obk8176014uqher834@olio-obk.de>
 Oliver Scherer <oli-obk@users.noreply.github.com> <rustc-contact@oli-obk.de>
 Oliver Scherer <oli-obk@users.noreply.github.com>
+Onur Özkan <onurozkan.dev@outlook.com> <contact@onurozkan.dev>
 Onur Özkan <onurozkan.dev@outlook.com> <work@onurozkan.dev>
 Onur Özkan <onurozkan.dev@outlook.com>
 Ömer Sinan Ağacan <omeragacan@gmail.com>
@@ -591,6 +599,7 @@ Rusty Blitzerr <rusty.blitzerr@gmail.com>
 RustyYato <krishna.sd.2012@gmail.com>
 Ruud van Asseldonk <dev@veniogames.com> Ruud van Asseldonk <ruuda@google.com>
 Ryan Leung <rleungx@gmail.com>
+Ryan Levick <me@ryanlevick.com> <rylev@users.noreply.github.com>
 Ryan Scheel <ryan.havvy@gmail.com>
 Ryan Sullivant <rsulli55@gmail.com>
 Ryan Wiedemann <Ryan1729@gmail.com>
@@ -686,6 +695,8 @@ Weihang Lo <me@weihanglo.tw>
 Weihang Lo <me@weihanglo.tw> <weihanglo@users.noreply.github.com>
 Wesley Wiser <wwiser@gmail.com> <wesleywiser@microsoft.com>
 whitequark <whitequark@whitequark.org>
+Will Crichton <crichton.will@gmail.com> <wcrichto@stanford.edu>
+Will Crichton <crichton.will@gmail.com> <wcrichto@cs.stanford.edu>
 William Ting <io@williamting.com> <william.h.ting@gmail.com>
 Wim Looman <wim@nemo157.com> <rust-lang@nemo157.com>
 Wim Looman <wim@nemo157.com> <git@nemo157.com>
@@ -695,6 +706,8 @@ Xinye Tao <xy.tao@outlook.com>
 Xuefeng Wu <benewu@gmail.com> Xuefeng Wu <xfwu@thoughtworks.com>
 Xuefeng Wu <benewu@gmail.com> XuefengWu <benewu@gmail.com>
 York Xiang <bombless@126.com>
+Yoshua Wuyts <yoshuawuyts@gmail.com> <yoshuawuyts+github@gmail.com>
+Yoshua Wuyts <yoshuawuyts@gmail.com> <2467194+yoshuawuyts@users.noreply.github.com>
 Yotam Ofek <yotam.ofek@gmail.com> <yotamofek@microsoft.com>
 Youngsoo Son <ysson83@gmail.com> <ysoo.son@samsung.com>
 Youngsuk Kim <joseph942010@gmail.com>

compiler/rustc_builtin_macros/src/test.rs

@@ -207,30 +207,30 @@ pub(crate) fn expand_test_or_bench(
     };
 
     let test_fn = if is_bench {
-        // A simple ident for a lambda
-        let b = Ident::from_str_and_span("b", attr_sp);
-
+        // avoid name collisions by using the function name within the identifier, see bug #148275
+        let bencher_param =
+            Ident::from_str_and_span(&format!("__bench_{}", fn_.ident.name), attr_sp);
         cx.expr_call(
             sp,
             cx.expr_path(test_path("StaticBenchFn")),
             thin_vec![
                 // #[coverage(off)]
-                // |b| self::test::assert_test_result(
+                // |__bench_fn_name| self::test::assert_test_result(
                 coverage_off(cx.lambda1(
                     sp,
                     cx.expr_call(
                         sp,
                         cx.expr_path(test_path("assert_test_result")),
                         thin_vec![
-                            // super::$test_fn(b)
+                            // super::$test_fn(__bench_fn_name)
                             cx.expr_call(
                                 ret_ty_sp,
                                 cx.expr_path(cx.path(sp, vec![fn_.ident])),
-                                thin_vec![cx.expr_ident(sp, b)],
+                                thin_vec![cx.expr_ident(sp, bencher_param)],
                             ),
                         ],
                     ),
-                    b,
+                    bencher_param,
                 )), // )
             ],
         )

compiler/rustc_const_eval/src/util/alignment.rs

@@ -1,24 +1,24 @@
 use rustc_abi::Align;
 use rustc_middle::mir::*;
-use rustc_middle::ty::{self, TyCtxt};
+use rustc_middle::ty::{self, AdtDef, TyCtxt};
 use tracing::debug;
 
-/// Returns `true` if this place is allowed to be less aligned
-/// than its containing struct (because it is within a packed
-/// struct).
-pub fn is_disaligned<'tcx, L>(
+/// If the place may be less aligned than its type requires
+/// (because it is in a packed type), returns the AdtDef
+/// and packed alignment of its most-unaligned projection.
+pub fn place_unalignment<'tcx, L>(
     tcx: TyCtxt<'tcx>,
     local_decls: &L,
     typing_env: ty::TypingEnv<'tcx>,
     place: Place<'tcx>,
-) -> bool
+) -> Option<(AdtDef<'tcx>, Align)>
 where
     L: HasLocalDecls<'tcx>,
 {
-    debug!("is_disaligned({:?})", place);
-    let Some(pack) = is_within_packed(tcx, local_decls, place) else {
-        debug!("is_disaligned({:?}) - not within packed", place);
-        return false;
+    debug!("unalignment({:?})", place);
+    let Some((descr, pack)) = most_packed_projection(tcx, local_decls, place) else {
+        debug!("unalignment({:?}) - not within packed", place);
+        return None;
     };
 
     let ty = place.ty(local_decls, tcx).ty;
@@ -30,31 +30,34 @@ where
                     || matches!(unsized_tail().kind(), ty::Slice(..) | ty::Str)) =>
         {
             // If the packed alignment is greater or equal to the field alignment, the type won't be
-            // further disaligned.
+            // further unaligned.
             // However we need to ensure the field is sized; for unsized fields, `layout.align` is
             // just an approximation -- except when the unsized tail is a slice, where the alignment
             // is fully determined by the type.
             debug!(
-                "is_disaligned({:?}) - align = {}, packed = {}; not disaligned",
+                "unalignment({:?}) - align = {}, packed = {}; not unaligned",
                 place,
                 layout.align.bytes(),
                 pack.bytes()
             );
-            false
+            None
         }
         _ => {
-            // We cannot figure out the layout. Conservatively assume that this is disaligned.
-            debug!("is_disaligned({:?}) - true", place);
-            true
+            // We cannot figure out the layout. Conservatively assume that this is unaligned.
+            debug!("unalignment({:?}) - unaligned", place);
+            Some((descr, pack))
         }
     }
 }
 
-pub fn is_within_packed<'tcx, L>(
+/// If the place includes a projection from a packed struct,
+/// returns the AdtDef and packed alignment of the projection
+/// with the lowest pack
+pub fn most_packed_projection<'tcx, L>(
     tcx: TyCtxt<'tcx>,
     local_decls: &L,
     place: Place<'tcx>,
-) -> Option<Align>
+) -> Option<(AdtDef<'tcx>, Align)>
 where
     L: HasLocalDecls<'tcx>,
 {
@@ -65,9 +68,11 @@ where
         .take_while(|(_base, elem)| !matches!(elem, ProjectionElem::Deref))
         // Consider the packed alignments at play here...
         .filter_map(|(base, _elem)| {
-            base.ty(local_decls, tcx).ty.ty_adt_def().and_then(|adt| adt.repr().pack)
+            let adt = base.ty(local_decls, tcx).ty.ty_adt_def()?;
+            let pack = adt.repr().pack?;
+            Some((adt, pack))
         })
         // ... and compute their minimum.
         // The overall smallest alignment is what matters.
-        .min()
+        .min_by_key(|(_, align)| *align)
 }

compiler/rustc_const_eval/src/util/mod.rs

@@ -6,7 +6,7 @@ mod check_validity_requirement;
 mod compare_types;
 mod type_name;
 
-pub use self::alignment::{is_disaligned, is_within_packed};
+pub use self::alignment::{most_packed_projection, place_unalignment};
 pub use self::check_validity_requirement::check_validity_requirement;
 pub(crate) use self::check_validity_requirement::validate_scalar_in_layout;
 pub use self::compare_types::{relate_types, sub_types};

compiler/rustc_lint/src/types.rs

@@ -1022,7 +1022,8 @@ declare_lint! {
     ///
     /// - Passing `Ordering::Release` or `Ordering::AcqRel` as the failure
     ///   ordering for any of `AtomicType::compare_exchange`,
-    ///   `AtomicType::compare_exchange_weak`, or `AtomicType::fetch_update`.
+    ///   `AtomicType::compare_exchange_weak`, `AtomicType::update`, or
+    ///   `AtomicType::try_update`.
     INVALID_ATOMIC_ORDERING,
     Deny,
     "usage of invalid atomic ordering in atomic operations and memory fences"
@@ -1118,13 +1119,19 @@ impl InvalidAtomicOrdering {
         let Some((method, args)) = Self::inherent_atomic_method_call(
             cx,
             expr,
-            &[sym::fetch_update, sym::compare_exchange, sym::compare_exchange_weak],
+            &[
+                sym::update,
+                sym::try_update,
+                sym::fetch_update,
+                sym::compare_exchange,
+                sym::compare_exchange_weak,
+            ],
         ) else {
             return;
         };
 
         let fail_order_arg = match method {
-            sym::fetch_update => &args[1],
+            sym::update | sym::try_update | sym::fetch_update => &args[1],
             sym::compare_exchange | sym::compare_exchange_weak => &args[3],
             _ => return,
         };

compiler/rustc_mir_transform/messages.ftl

@@ -69,8 +69,11 @@ mir_transform_tail_expr_local = {$is_generated_name ->
         *[false] `{$name}` calls a custom destructor
     }
 
-mir_transform_unaligned_packed_ref = reference to packed field is unaligned
-    .note = packed structs are only aligned by one byte, and many modern architectures penalize unaligned field accesses
+mir_transform_unaligned_packed_ref = reference to field of packed {$ty_descr} is unaligned
+    .note = this {$ty_descr} is {$align ->
+        [one] {""}
+        *[other] {"at most "}
+    }{$align}-byte aligned, but the type of this field may require higher alignment
     .note_ub = creating a misaligned reference is undefined behavior (even if that reference is never dereferenced)
     .help = copy the field contents to a local variable, or replace the reference with a raw pointer and use `read_unaligned`/`write_unaligned` (loads and stores via `*p` must be properly aligned even when using raw pointers)
 

compiler/rustc_mir_transform/src/add_moves_for_packed_drops.rs

@@ -51,7 +51,7 @@ impl<'tcx> crate::MirPass<'tcx> for AddMovesForPackedDrops {
 
             match terminator.kind {
                 TerminatorKind::Drop { place, .. }
-                    if util::is_disaligned(tcx, body, typing_env, place) =>
+                    if util::place_unalignment(tcx, body, typing_env, place).is_some() =>
                 {
                     add_move_for_packed_drop(
                         tcx,

compiler/rustc_mir_transform/src/check_packed_ref.rs

@@ -37,7 +37,9 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
     }
 
     fn visit_place(&mut self, place: &Place<'tcx>, context: PlaceContext, _location: Location) {
-        if context.is_borrow() && util::is_disaligned(self.tcx, self.body, self.typing_env, *place)
+        if context.is_borrow()
+            && let Some((adt, pack)) =
+                util::place_unalignment(self.tcx, self.body, self.typing_env, *place)
         {
             let def_id = self.body.source.instance.def_id();
             if let Some(impl_def_id) = self.tcx.trait_impl_of_assoc(def_id)
@@ -48,7 +50,11 @@ impl<'tcx> Visitor<'tcx> for PackedRefChecker<'_, 'tcx> {
                 // shouldn't do.
                 span_bug!(self.source_info.span, "builtin derive created an unaligned reference");
             } else {
-                self.tcx.dcx().emit_err(errors::UnalignedPackedRef { span: self.source_info.span });
+                self.tcx.dcx().emit_err(errors::UnalignedPackedRef {
+                    span: self.source_info.span,
+                    ty_descr: adt.descr(),
+                    align: pack.bytes(),
+                });
             }
         }
     }

compiler/rustc_mir_transform/src/dead_store_elimination.rs

@@ -23,7 +23,7 @@ use rustc_mir_dataflow::impls::{
 };
 
 use crate::simplify::UsedInStmtLocals;
-use crate::util::is_within_packed;
+use crate::util::most_packed_projection;
 
 /// Performs the optimization on the body
 ///
@@ -65,7 +65,7 @@ fn eliminate<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) -> bool {
                     // the move may be codegened as a pointer to that field.
                     // Using that disaligned pointer may trigger UB in the callee,
                     // so do nothing.
-                    && is_within_packed(tcx, body, place).is_none()
+                    && most_packed_projection(tcx, body, place).is_none()
                 {
                     call_operands_to_move.push((bb, index));
                 }

compiler/rustc_mir_transform/src/errors.rs

@@ -99,6 +99,8 @@ pub(crate) enum ConstMutate {
 pub(crate) struct UnalignedPackedRef {
     #[primary_span]
     pub span: Span,
+    pub ty_descr: &'static str,
+    pub align: u64,
 }
 
 #[derive(Diagnostic)]

compiler/rustc_mir_transform/src/validate.rs

@@ -20,7 +20,7 @@ use rustc_middle::{bug, span_bug};
 use rustc_mir_dataflow::debuginfo::debuginfo_locals;
 use rustc_trait_selection::traits::ObligationCtxt;
 
-use crate::util::{self, is_within_packed};
+use crate::util::{self, most_packed_projection};
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 enum EdgeKind {
@@ -409,7 +409,9 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
 
                     // The call destination place and Operand::Move place used as an argument might
                     // be passed by a reference to the callee. Consequently they cannot be packed.
-                    if is_within_packed(self.tcx, &self.body.local_decls, destination).is_some() {
+                    if most_packed_projection(self.tcx, &self.body.local_decls, destination)
+                        .is_some()
+                    {
                         // This is bad! The callee will expect the memory to be aligned.
                         self.fail(
                             location,
@@ -423,7 +425,9 @@ impl<'a, 'tcx> Visitor<'tcx> for CfgChecker<'a, 'tcx> {
 
                 for arg in args {
                     if let Operand::Move(place) = &arg.node {
-                        if is_within_packed(self.tcx, &self.body.local_decls, *place).is_some() {
+                        if most_packed_projection(self.tcx, &self.body.local_decls, *place)
+                            .is_some()
+                        {
                             // This is bad! The callee will expect the memory to be aligned.
                             self.fail(
                                 location,