Rollup of 9 pull requests

.mailmap

@@ -162,8 +162,10 @@ David Carlier <[email protected]>
 David Klein <[email protected]>
 David Manescu <[email protected]> <[email protected]>
 David Ross <[email protected]>
-David Wood <[email protected]> <[email protected]>
+David Wood <[email protected]> <[email protected]>
+David Wood <[email protected]> <[email protected]>
 David Wood <[email protected]> <[email protected]>
+David Wood <[email protected]> <[email protected]>
 Deadbeef <[email protected]>
 Deadbeef <[email protected]> <[email protected]>
 dependabot[bot] <dependabot[bot]@users.noreply.github.com> <27856297+dependabot-preview[bot]@users.noreply.github.com>

Cargo.lock

@@ -3655,7 +3655,6 @@ dependencies = [
  "rustc_macros",
  "rustc_serialize",
  "rustc_span",
- "smallvec",
  "tracing",
  "unic-langid",
 ]
@@ -4446,7 +4445,6 @@ dependencies = [
  "rustc_serialize",
  "rustc_span",
  "rustc_target",
- "smallvec",
  "termize",
  "tracing",
  "windows",

compiler/rustc_ast/src/token.rs

@@ -1085,6 +1085,7 @@ pub enum NtExprKind {
     Expr2021 { inferred: bool },
 }
 
+/// A macro nonterminal, known in documentation as a fragment specifier.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Encodable, Decodable, Hash, HashStable_Generic)]
 pub enum NonterminalKind {
     Item,

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -71,7 +71,6 @@ impl<'tcx> BorrowExplanation<'tcx> {
     ) {
         let tcx = cx.infcx.tcx;
         let body = cx.body;
-        let local_names = &cx.local_names;
 
         if let Some(span) = borrow_span {
             let def_id = body.source.def_id();
@@ -220,7 +219,7 @@ impl<'tcx> BorrowExplanation<'tcx> {
                     _ => ("destructor", format!("type `{}`", local_decl.ty)),
                 };
 
-                match local_names[dropped_local] {
+                match cx.local_name(dropped_local) {
                     Some(local_name) if !local_decl.from_compiler_desugaring() => {
                         let message = format!(
                             "{borrow_desc}borrow might be used here, when `{local_name}` is dropped \
@@ -670,10 +669,10 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
 
             Some(Cause::DropVar(local, location)) => {
                 let mut should_note_order = false;
-                if self.local_names[local].is_some()
+                if self.local_name(local).is_some()
                     && let Some((WriteKind::StorageDeadOrDrop, place)) = kind_place
                     && let Some(borrowed_local) = place.as_local()
-                    && self.local_names[borrowed_local].is_some()
+                    && self.local_name(borrowed_local).is_some()
                     && local != borrowed_local
                 {
                     should_note_order = true;
@@ -748,7 +747,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
                         Operand::Copy(place) | Operand::Move(place) => {
                             if let Some(l) = place.as_local() {
                                 let local_decl = &self.body.local_decls[l];
-                                if self.local_names[l].is_none() {
+                                if self.local_name(l).is_none() {
                                     local_decl.source_info.span
                                 } else {
                                     span
@@ -793,7 +792,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
                             Operand::Copy(place) | Operand::Move(place) => {
                                 if let Some(l) = place.as_local() {
                                     let local_decl = &self.body.local_decls[l];
-                                    if self.local_names[l].is_none() {
+                                    if self.local_name(l).is_none() {
                                         local_decl.source_info.span
                                     } else {
                                         span

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -7,17 +7,17 @@ use rustc_data_structures::fx::FxIndexMap;
 use rustc_errors::{Applicability, Diag, EmissionGuarantee, MultiSpan, listify};
 use rustc_hir::def::{CtorKind, Namespace};
 use rustc_hir::{self as hir, CoroutineKind, LangItem};
-use rustc_index::IndexSlice;
+use rustc_index::{IndexSlice, IndexVec};
 use rustc_infer::infer::{BoundRegionConversionTime, NllRegionVariableOrigin};
 use rustc_infer::traits::SelectionError;
-use rustc_middle::bug;
 use rustc_middle::mir::{
     AggregateKind, CallSource, ConstOperand, ConstraintCategory, FakeReadCause, Local, LocalInfo,
     LocalKind, Location, Operand, Place, PlaceRef, PlaceTy, ProjectionElem, Rvalue, Statement,
-    StatementKind, Terminator, TerminatorKind, find_self_call,
+    StatementKind, Terminator, TerminatorKind, VarDebugInfoContents, find_self_call,
 };
 use rustc_middle::ty::print::Print;
 use rustc_middle::ty::{self, Ty, TyCtxt};
+use rustc_middle::{bug, span_bug};
 use rustc_mir_dataflow::move_paths::{InitLocation, LookupResult, MoveOutIndex};
 use rustc_span::def_id::LocalDefId;
 use rustc_span::source_map::Spanned;
@@ -190,6 +190,36 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     ) -> Option<&(PlaceRef<'tcx>, Diag<'infcx>)> {
         self.diags_buffer.buffered_move_errors.get(move_out_indices)
     }
+
+    /// Uses `body.var_debug_info` to find the symbol
+    fn local_name(&self, index: Local) -> Option<Symbol> {
+        *self.local_names().get(index)?
+    }
+
+    fn local_names(&self) -> &IndexSlice<Local, Option<Symbol>> {
+        self.local_names.get_or_init(|| {
+            let mut local_names = IndexVec::from_elem(None, &self.body.local_decls);
+            for var_debug_info in &self.body.var_debug_info {
+                if let VarDebugInfoContents::Place(place) = var_debug_info.value {
+                    if let Some(local) = place.as_local() {
+                        if let Some(prev_name) = local_names[local]
+                            && var_debug_info.name != prev_name
+                        {
+                            span_bug!(
+                                var_debug_info.source_info.span,
+                                "local {:?} has many names (`{}` vs `{}`)",
+                                local,
+                                prev_name,
+                                var_debug_info.name
+                            );
+                        }
+                        local_names[local] = Some(var_debug_info.name);
+                    }
+                }
+            }
+            local_names
+        })
+    }
 }
 
 impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
@@ -430,7 +460,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
     /// a name, or its name was generated by the compiler, then `Err` is returned
     fn append_local_to_string(&self, local: Local, buf: &mut String) -> Result<(), ()> {
         let decl = &self.body.local_decls[local];
-        match self.local_names[local] {
+        match self.local_name(local) {
             Some(name) if !decl.from_compiler_desugaring() => {
                 buf.push_str(name.as_str());
                 Ok(())
@@ -1500,4 +1530,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             }
         }
     }
+
+    /// Skip over locals that begin with an underscore or have no name
+    pub(crate) fn local_excluded_from_unused_mut_lint(&self, index: Local) -> bool {
+        self.local_name(index).is_none_or(|name| name.as_str().starts_with('_'))
+    }
 }

compiler/rustc_borrowck/src/diagnostics/move_errors.rs

@@ -465,11 +465,15 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
 
         if let PlaceRef { local, projection: [] } = deref_base {
             let decl = &self.body.local_decls[local];
+            let local_name = self.local_name(local).map(|sym| format!("`{sym}`"));
             if decl.is_ref_for_guard() {
                 return self
                     .cannot_move_out_of(
                         span,
-                        &format!("`{}` in pattern guard", self.local_names[local].unwrap()),
+                        &format!(
+                            "{} in pattern guard",
+                            local_name.as_deref().unwrap_or("the place")
+                        ),
                     )
                     .with_note(
                         "variables bound in patterns cannot be moved from \
@@ -825,7 +829,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
             }
 
             if binds_to.len() == 1 {
-                let place_desc = &format!("`{}`", self.local_names[*local].unwrap());
+                let place_desc = self.local_name(*local).map(|sym| format!("`{sym}`"));
 
                 if let Some(expr) = self.find_expr(binding_span) {
                     self.suggest_cloning(err, bind_to.ty, expr, None);
@@ -834,7 +838,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 err.subdiagnostic(crate::session_diagnostics::TypeNoCopy::Label {
                     is_partial_move: false,
                     ty: bind_to.ty,
-                    place: place_desc,
+                    place: place_desc.as_deref().unwrap_or("the place"),
                     span: binding_span,
                 });
             }

compiler/rustc_borrowck/src/diagnostics/mutability_errors.rs

@@ -60,7 +60,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 if access_place.as_local().is_some() {
                     reason = ", as it is not declared as mutable".to_string();
                 } else {
-                    let name = self.local_names[local].expect("immutable unnamed local");
+                    let name = self.local_name(local).expect("immutable unnamed local");
                     reason = format!(", as `{name}` is not declared as mutable");
                 }
             }
@@ -285,7 +285,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     .body
                     .local_decls
                     .get(local)
-                    .is_some_and(|l| mut_borrow_of_mutable_ref(l, self.local_names[local])) =>
+                    .is_some_and(|l| mut_borrow_of_mutable_ref(l, self.local_name(local))) =>
             {
                 let decl = &self.body.local_decls[local];
                 err.span_label(span, format!("cannot {act}"));
@@ -481,7 +481,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                 let (pointer_sigil, pointer_desc) =
                     if local_decl.ty.is_ref() { ("&", "reference") } else { ("*const", "pointer") };
 
-                match self.local_names[local] {
+                match self.local_name(local) {
                     Some(name) if !local_decl.from_compiler_desugaring() => {
                         err.span_label(
                             span,

compiler/rustc_borrowck/src/diagnostics/region_errors.rs

@@ -664,14 +664,14 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         let fr_name_and_span = self.regioncx.get_var_name_and_span_for_region(
             self.infcx.tcx,
             self.body,
-            &self.local_names,
+            &self.local_names(),
             &self.upvars,
             errci.fr,
         );
         let outlived_fr_name_and_span = self.regioncx.get_var_name_and_span_for_region(
             self.infcx.tcx,
             self.body,
-            &self.local_names,
+            &self.local_names(),
             &self.upvars,
             errci.outlived_fr,
         );

compiler/rustc_borrowck/src/diagnostics/region_name.rs

@@ -399,7 +399,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
             [implicit_inputs + argument_index];
         let (_, span) = self.regioncx.get_argument_name_and_span_for_region(
             self.body,
-            &self.local_names,
+            self.local_names(),
             argument_index,
         );
 
@@ -973,7 +973,7 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
         {
             let (arg_name, arg_span) = self.regioncx.get_argument_name_and_span_for_region(
                 self.body,
-                &self.local_names,
+                self.local_names(),
                 arg_index,
             );
             let region_name = self.synthesize_region_name();

compiler/rustc_borrowck/src/lib.rs

@@ -16,7 +16,7 @@
 // tidy-alphabetical-end
 
 use std::borrow::Cow;
-use std::cell::RefCell;
+use std::cell::{OnceCell, RefCell};
 use std::marker::PhantomData;
 use std::ops::{ControlFlow, Deref};
 
@@ -391,7 +391,7 @@ fn do_mir_borrowck<'tcx>(
             used_mut_upvars: SmallVec::new(),
             borrow_set: &borrow_set,
             upvars: &[],
-            local_names: IndexVec::from_elem(None, &promoted_body.local_decls),
+            local_names: OnceCell::from(IndexVec::from_elem(None, &promoted_body.local_decls)),
             region_names: RefCell::default(),
             next_region_name: RefCell::new(1),
             polonius_output: None,
@@ -414,26 +414,6 @@ fn do_mir_borrowck<'tcx>(
         promoted_mbcx.report_move_errors();
     }
 
-    let mut local_names = IndexVec::from_elem(None, &body.local_decls);
-    for var_debug_info in &body.var_debug_info {
-        if let VarDebugInfoContents::Place(place) = var_debug_info.value {
-            if let Some(local) = place.as_local() {
-                if let Some(prev_name) = local_names[local]
-                    && var_debug_info.name != prev_name
-                {
-                    span_bug!(
-                        var_debug_info.source_info.span,
-                        "local {:?} has many names (`{}` vs `{}`)",
-                        local,
-                        prev_name,
-                        var_debug_info.name
-                    );
-                }
-                local_names[local] = Some(var_debug_info.name);
-            }
-        }
-    }
-
     let mut mbcx = MirBorrowckCtxt {
         root_cx,
         infcx: &infcx,
@@ -450,7 +430,7 @@ fn do_mir_borrowck<'tcx>(
         used_mut_upvars: SmallVec::new(),
         borrow_set: &borrow_set,
         upvars: tcx.closure_captures(def),
-        local_names,
+        local_names: OnceCell::new(),
         region_names: RefCell::default(),
         next_region_name: RefCell::new(1),
         move_errors: Vec::new(),
@@ -682,7 +662,7 @@ struct MirBorrowckCtxt<'a, 'infcx, 'tcx> {
     upvars: &'tcx [&'tcx ty::CapturedPlace<'tcx>],
 
     /// Names of local (user) variables (extracted from `var_debug_info`).
-    local_names: IndexVec<Local, Option<Symbol>>,
+    local_names: OnceCell<IndexVec<Local, Option<Symbol>>>,
 
     /// Record the region names generated for each region in the given
     /// MIR def so that we can reuse them later in help/error messages.
@@ -2610,7 +2590,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, '_, 'tcx> {
             };
 
             // Skip over locals that begin with an underscore or have no name
-            if self.local_names[local].is_none_or(|name| name.as_str().starts_with('_')) {
+            if self.local_excluded_from_unused_mut_lint(local) {
                 continue;
             }
 

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -865,7 +865,7 @@ fn link_natively(
                     command: cmd,
                     escaped_output,
                     verbose: sess.opts.verbose,
-                    sysroot_dir: sess.sysroot.clone(),
+                    sysroot_dir: sess.opts.sysroot.path().to_owned(),
                 };
                 sess.dcx().emit_err(err);
                 // If MSVC's `link.exe` was expected but the return code
@@ -1249,10 +1249,10 @@ fn link_sanitizer_runtime(
         if path.exists() {
             sess.target_tlib_path.dir.clone()
         } else {
-            let default_sysroot = filesearch::get_or_default_sysroot();
-            let default_tlib =
-                filesearch::make_target_lib_path(&default_sysroot, sess.opts.target_triple.tuple());
-            default_tlib
+            filesearch::make_target_lib_path(
+                &sess.opts.sysroot.default,
+                sess.opts.target_triple.tuple(),
+            )
         }
     }
 
@@ -1758,7 +1758,7 @@ fn detect_self_contained_mingw(sess: &Session, linker: &Path) -> bool {
     for dir in env::split_paths(&env::var_os("PATH").unwrap_or_default()) {
         let full_path = dir.join(&linker_with_extension);
         // If linker comes from sysroot assume self-contained mode
-        if full_path.is_file() && !full_path.starts_with(&sess.sysroot) {
+        if full_path.is_file() && !full_path.starts_with(sess.opts.sysroot.path()) {
             return false;
         }
     }

compiler/rustc_codegen_ssa/src/back/linker.rs

@@ -1059,7 +1059,7 @@ impl<'a> Linker for MsvcLinker<'a> {
         self.link_arg("/PDBALTPATH:%_PDB%");
 
         // This will cause the Microsoft linker to embed .natvis info into the PDB file
-        let natvis_dir_path = self.sess.sysroot.join("lib\\rustlib\\etc");
+        let natvis_dir_path = self.sess.opts.sysroot.path().join("lib\\rustlib\\etc");
         if let Ok(natvis_dir) = fs::read_dir(&natvis_dir_path) {
             for entry in natvis_dir {
                 match entry {