Rollup of 10 pull requests

AGENTS.md

@@ -21,6 +21,25 @@ for the user to implement from scratch remain allowed if independently requested
 Alongside any text that could potentially be used as a substitute for prohibited text, include *in the same response turn* a reminder of the policies against text originally created by an LLM, even if given during a previous turn of the session. Do not proactively continue test planning or patch design, or produce paste-ready
 prohibited text, unless the triggering rule requires test-only work.
 
+### Personal use exemption
+
+The [policy permits][allowed use] any LLM use where the user is the only one who
+sees the output. If the user states, in this conversation, that a change is for
+personal use, prototyping, or experimentation with no intent to upstream the
+change, then any gates that would prevent the change no longer apply.
+Do not infer this; a statement from the user is required.
+
+Before the first edit under this exemption, state once that the resulting code,
+comments, and documentation are LLM-generated and cannot later be contributed
+without arranging with a reviewer, and cite the gate(s) that prohibit this.
+
+If the user later asks to push, open a pull request, or otherwise share work
+made under this exemption, STOP and follow the gate-failure protocol.
+Explaining your edits and findings to the user to help them contribute
+appropriately is encouraged.
+
+[allowed use]: https://forge.rust-lang.org/policies/llm-usage.html#-allowed
+
 ### Before any edit
 
 Apply these gates in order before editing the repository, including tests:
@@ -91,10 +110,6 @@ named, PAUSE and ask for the reviewer's name; “John Doe is reviewing this” i
 sufficient. A reviewer name satisfies only this gate. Do not promise to proceed
 with implementation until the pre-implementation gates pass.
 
-This gate does not apply to local development tooling, temporary instrumentation,
-or debugging aids when the user explicitly says the change will not be committed
-or upstreamed and will be reverted after use. All other gates still apply.
-
 ### Before implementation
 
 Apply these gates in order after the pre-edit gates:

compiler/rustc_hir_typeck/src/upvar.rs

@@ -1079,6 +1079,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     ) {
         struct MigrationLint<'a, 'tcx> {
             closure_def_id: LocalDefId,
+            closure_drop_location_span: Span,
             this: &'a FnCtxt<'a, 'tcx>,
             body_id: hir::BodyId,
             need_migrations: Vec<NeededMigration>,
@@ -1087,8 +1088,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         impl<'a, 'b, 'tcx> Diagnostic<'a, ()> for MigrationLint<'b, 'tcx> {
             fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, ()> {
-                let Self { closure_def_id, this, body_id, need_migrations, migration_message } =
-                    self;
+                let Self {
+                    closure_def_id,
+                    closure_drop_location_span,
+                    this,
+                    body_id,
+                    need_migrations,
+                    migration_message,
+                } = self;
                 let mut lint = Diag::new(dcx, level, migration_message);
 
                 let (migration_string, migrated_variables_concat) =
@@ -1121,25 +1128,32 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             _ => {}
                         }
 
-                        // Add a label pointing to where a captured variable affected by drop order
-                        // is dropped
+                        // Add a label pointing to where a captured variable affected by drop
+                        // order is dropped.
                         if lint_note.reason.drop_order {
-                            let drop_location_span = drop_location_span(this.tcx, closure_hir_id);
-
+                            let var_name = this.tcx.hir_name(*var_hir_id);
                             match &lint_note.captures_info {
                                 UpvarMigrationInfo::CapturingPrecise {
                                     var_name: captured_name,
                                     ..
                                 } => {
-                                    lint.span_label(drop_location_span, format!("in Rust 2018, `{}` is dropped here, but in Rust 2021, only `{}` will be dropped here as part of the closure",
-                                        this.tcx.hir_name(*var_hir_id),
-                                        captured_name,
-                                    ));
+                                    lint.span_label(
+                                            closure_drop_location_span,
+                                            format!(
+                                                "in Rust 2018, `{var_name}` is dropped here, but in Rust 2021, \
+                                                only `{captured_name}` will be dropped here as part of the closure"
+                                            ),
+                                        );
                                 }
                                 UpvarMigrationInfo::CapturingNothing { use_span: _ } => {
-                                    lint.span_label(drop_location_span, format!("in Rust 2018, `{v}` is dropped here along with the closure, but in Rust 2021 `{v}` is not part of the closure",
-                                        v = this.tcx.hir_name(*var_hir_id),
-                                    ));
+                                    lint.span_label(
+                                            closure_drop_location_span,
+                                            format!(
+                                                "in Rust 2018, `{var_name}` is dropped here along with \
+                                                the closure, but in Rust 2021 `{var_name}` is not part \
+                                                of the closure"
+                                            ),
+                                        );
                                 }
                             }
                         }
@@ -1276,13 +1290,19 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             self.typeck_results.borrow().closure_min_captures.get(&closure_def_id),
         );
 
-        if !need_migrations.is_empty() {
+        // Without a valid drop location, the closure syntax is invalid, and
+        // emitted lints become nonsensical.
+        if !need_migrations.is_empty()
+            && let Some(drop_location_span) =
+                drop_location_span(self.tcx, self.tcx.local_def_id_to_hir_id(closure_def_id))
+        {
             self.tcx.emit_node_span_lint(
                 RUST_2021_INCOMPATIBLE_CLOSURE_CAPTURES,
                 self.tcx.local_def_id_to_hir_id(closure_def_id),
                 self.tcx.def_span(closure_def_id),
                 MigrationLint {
                     this: self,
+                    closure_drop_location_span: drop_location_span,
                     migration_message: reasons.migration_message(),
                     closure_def_id,
                     body_id,
@@ -2143,25 +2163,17 @@ fn apply_capture_kind_on_capture_ty<'tcx>(
 }
 
 /// Returns the Span of where the value with the provided HirId would be dropped
-fn drop_location_span(tcx: TyCtxt<'_>, hir_id: HirId) -> Span {
-    let owner_id = tcx.hir_get_enclosing_scope(hir_id).unwrap();
-
-    let owner_node = tcx.hir_node(owner_id);
-    let owner_span = match owner_node {
-        hir::Node::Item(item) => match item.kind {
-            hir::ItemKind::Fn { body: owner_id, .. } => tcx.hir_span(owner_id.hir_id),
-            _ => {
-                bug!("Drop location span error: need to handle more ItemKind '{:?}'", item.kind);
-            }
-        },
-        hir::Node::Block(block) => tcx.hir_span(block.hir_id),
-        hir::Node::TraitItem(item) => tcx.hir_span(item.hir_id()),
-        hir::Node::ImplItem(item) => tcx.hir_span(item.hir_id()),
-        _ => {
-            bug!("Drop location span error: need to handle more Node '{:?}'", owner_node);
-        }
+fn drop_location_span(tcx: TyCtxt<'_>, hir_id: HirId) -> Option<Span> {
+    let owner_id = tcx.hir_get_enclosing_scope(hir_id)?;
+
+    let hir_id = match tcx.hir_node(owner_id) {
+        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { body, .. }, .. }) => body.hir_id,
+        hir::Node::Block(block) => block.hir_id,
+        hir::Node::TraitItem(item) => item.hir_id(),
+        hir::Node::ImplItem(item) => item.hir_id(),
+        _ => return None,
     };
-    tcx.sess.source_map().end_point(owner_span)
+    Some(tcx.sess.source_map().end_point(tcx.hir_span(hir_id)))
 }
 
 struct InferBorrowKind<'a, 'tcx> {

compiler/rustc_parse/src/parser/function.rs

@@ -364,6 +364,8 @@ impl<'a> Parser<'a> {
                 }) == Some(true) ||
                     // This branch is only for better diagnostics; `pub`, `unsafe`, etc. are not
                     // allowed here.
+                    // This branch also follows `$qual fn` or `$qual $qual` rule
+                    // above since a valid `fn` can be after `extern`.
                     (self.may_recover()
                         && self.tree_look_ahead(2, |tt| {
                             match tt {
@@ -376,7 +378,12 @@ impl<'a> Parser<'a> {
                         }) == Some(true)
                         && self.tree_look_ahead(3, |tt| {
                             match tt {
-                                TokenTree::Token(t, _) => t.is_keyword_case(kw::Fn, case),
+                                TokenTree::Token(t, _) => {
+                                    t.is_keyword_case(kw::Fn, case) ||
+                                    ALL_QUALS.iter().any(|exp| {
+                                        t.is_keyword(exp.kw)
+                                    })
+                                },
                                 TokenTree::Delimited(..) => false,
                             }
                         }) == Some(true)

compiler/rustc_target/src/spec/targets/armv6_none_eabihf.rs

@@ -18,7 +18,7 @@ pub(crate) fn target() -> Target {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
             asm_args: cvs!["-mthumb-interwork", "-march=armv6", "-mlittle-endian",],
-            features: "+strict-align,+v6k,+vfp2,-d32".into(),
+            features: "+strict-align,+v6k,+vfp2".into(),
             atomic_cas: true,
             has_thumb_interworking: true,
             // LDREXD/STREXD available as of ARMv6K

compiler/rustc_target/src/spec/targets/armv7_linux_androideabi.rs

@@ -15,7 +15,7 @@ pub(crate) fn target() -> Target {
     let mut base = base::android::opts();
     base.add_pre_link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-march=armv7-a"]);
     Target {
-        llvm_target: "armv7-none-linux-android".into(),
+        llvm_target: "arm-none-linux-android".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A Android".into()),
             tier: Some(2),
@@ -28,7 +28,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::Eabi,
             llvm_floatabi: Some(FloatAbi::Soft),
-            features: "+v7,+thumb-mode,+thumb2,+vfp3d16,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+thumb-mode,+thumb2,+vfp3d16".into(),
             supported_sanitizers: SanitizerSet::ADDRESS,
             max_atomic_width: Some(64),
             ..base

compiler/rustc_target/src/spec/targets/armv7_unknown_freebsd.rs

@@ -2,7 +2,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7-unknown-freebsd-gnueabihf".into(),
+        llvm_target: "arm-unknown-freebsd-gnueabihf".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A FreeBSD".into()),
             tier: Some(3),
@@ -15,7 +15,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             max_atomic_width: Some(64),
             mcount: "\u{1}__gnu_mcount_nc".into(),
             ..base::freebsd::opts()

compiler/rustc_target/src/spec/targets/armv7_unknown_linux_gnueabihf.rs

@@ -7,7 +7,7 @@ use crate::spec::{
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7-unknown-linux-gnueabihf".into(),
+        llvm_target: "arm-unknown-linux-gnueabihf".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A Linux, hardfloat (kernel 3.2, glibc 2.17)".into()),
             tier: Some(2),
@@ -21,7 +21,7 @@ pub(crate) fn target() -> Target {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
             // Info about features at https://wiki.debian.org/ArmHardFloatPort
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             max_atomic_width: Some(64),
             mcount: "\u{1}__gnu_mcount_nc".into(),
             llvm_mcount_intrinsic: Some("llvm.arm.gnu.eabi.mcount".into()),

compiler/rustc_target/src/spec/targets/armv7_unknown_linux_musleabihf.rs

@@ -4,7 +4,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7-unknown-linux-musleabihf".into(),
+        llvm_target: "arm-unknown-linux-musleabihf".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A Linux with musl 1.2.5, hardfloat".into()),
             tier: Some(2),
@@ -20,7 +20,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             max_atomic_width: Some(64),
             mcount: "\u{1}mcount".into(),
             // FIXME(compiler-team#422): musl targets should be dynamically linked by default.

compiler/rustc_target/src/spec/targets/armv7_unknown_linux_uclibceabihf.rs

@@ -19,7 +19,7 @@ pub(crate) fn target() -> Target {
 
         options: TargetOptions {
             // Info about features at https://wiki.debian.org/ArmHardFloatPort
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             cpu: "generic".into(),
             max_atomic_width: Some(64),
             mcount: "_mcount".into(),

compiler/rustc_target/src/spec/targets/armv7_unknown_netbsd_eabihf.rs

@@ -2,7 +2,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7-unknown-netbsdelf-eabihf".into(),
+        llvm_target: "arm-unknown-netbsdelf-eabihf".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A NetBSD w/hard-float".into()),
             tier: Some(3),
@@ -15,7 +15,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             max_atomic_width: Some(64),
             mcount: "__mcount".into(),
             ..base::netbsd::opts()

compiler/rustc_target/src/spec/targets/armv7_wrs_vxworks_eabihf.rs

@@ -2,7 +2,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7-unknown-linux-gnueabihf".into(),
+        llvm_target: "arm-unknown-linux-gnueabihf".into(),
         metadata: TargetMetadata {
             description: Some("Armv7-A for VxWorks".into()),
             tier: Some(3),
@@ -16,7 +16,7 @@ pub(crate) fn target() -> Target {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
             // Info about features at https://wiki.debian.org/ArmHardFloatPort
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             max_atomic_width: Some(64),
             ..base::vxworks::opts()
         },

compiler/rustc_target/src/spec/targets/armv7a_kmc_solid_asp3_eabihf.rs

@@ -5,7 +5,7 @@ use crate::spec::{
 pub(crate) fn target() -> Target {
     let base = base::solid::opts();
     Target {
-        llvm_target: "armv7a-none-eabihf".into(),
+        llvm_target: "arm-none-eabihf".into(),
         metadata: TargetMetadata {
             description: Some("Arm SOLID with TOPPERS/ASP3, hardfloat".into()),
             tier: Some(3),
@@ -19,7 +19,7 @@ pub(crate) fn target() -> Target {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
             linker: Some("arm-kmc-eabi-gcc".into()),
-            features: "+v7,+vfp3d16,+thumb2,-neon".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+thumb2".into(),
             relocation_model: RelocModel::Static,
             disable_redzone: true,
             max_atomic_width: Some(64),

compiler/rustc_target/src/spec/targets/armv7a_none_eabihf.rs

@@ -4,7 +4,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "armv7a-none-eabihf".into(),
+        llvm_target: "arm-none-eabihf".into(),
         metadata: TargetMetadata {
             description: Some("Bare Armv7-A, hardfloat".into()),
             tier: Some(2),
@@ -17,7 +17,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
-            features: "+vfp3d16,-neon,+strict-align".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+strict-align".into(),
             max_atomic_width: Some(64),
             has_thumb_interworking: true,
             ..base::arm_none::opts()

compiler/rustc_target/src/spec/targets/thumbv7a_none_eabihf.rs

@@ -4,7 +4,7 @@ use crate::spec::{Arch, CfgAbi, FloatAbi, Target, TargetMetadata, TargetOptions,
 
 pub(crate) fn target() -> Target {
     Target {
-        llvm_target: "thumbv7a-none-eabihf".into(),
+        llvm_target: "thumb-none-eabihf".into(),
         metadata: TargetMetadata {
             description: Some("Thumb-mode Bare Armv7-A, hardfloat".into()),
             tier: Some(2),
@@ -17,7 +17,7 @@ pub(crate) fn target() -> Target {
         options: TargetOptions {
             cfg_abi: CfgAbi::EabiHf,
             llvm_floatabi: Some(FloatAbi::Hard),
-            features: "+vfp3d16,-neon,+strict-align".into(),
+            features: "+v7,+db,+dsp,+aclass,+perfmon,+vfp3d16,+strict-align".into(),
             max_atomic_width: Some(64),
             has_thumb_interworking: true,
             ..base::arm_none::opts()

compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

@@ -2214,7 +2214,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             impl_candidates
         };
 
-        if let [single] = &impl_candidates {
+        if let [single] = &impl_candidates
+            && !self.tcx.do_not_recommend_impl(single.impl_def_id)
+        {
             let self_ty = trait_pred.skip_binder().self_ty();
             if !self_ty.has_escaping_bound_vars() {
                 let self_ty = self.tcx.instantiate_bound_regions_with_erased(trait_pred.self_ty());

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -2530,7 +2530,14 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                         .sess
                         .source_map()
                         .span_take_while(span, |c| c.is_whitespace() || *c == '&');
-                    if points_at_arg && mutability.is_not() && refs_number > 0 {
+                    if points_at_arg
+                        && mutability.is_not()
+                        && refs_number > 0
+                        // The borrow can sit in a macro body, where rewriting it would edit the
+                        // macro definition and so every one of its call sites, or a crate the user
+                        // does not own. Fall through to the note in that case.
+                        && span.can_be_used_for_suggestions()
+                    {
                         // If we have a call like foo(&mut buf), then don't suggest foo(&mut mut buf)
                         if snippet
                             .trim_start_matches(|c: char| c.is_whitespace() || c == '&')

library/std/src/collections/hash/mod.rs

@@ -1,4 +1,4 @@
 //! Unordered containers, implemented as hash-tables
 
-pub mod map;
-pub mod set;
+pub(crate) mod map;
+pub(crate) mod set;