Rollup of 15 pull requests

compiler/rustc_ast/src/ast.rs

@@ -2641,6 +2641,8 @@ pub enum SelfKind {
     Value(Mutability),
     /// `&'lt self`, `&'lt mut self`
     Region(Option<Lifetime>, Mutability),
+    /// `&'lt pin const self`, `&'lt pin mut self`
+    Pinned(Option<Lifetime>, Mutability),
     /// `self: TYPE`, `mut self: TYPE`
     Explicit(P<Ty>, Mutability),
 }
@@ -2650,6 +2652,8 @@ impl SelfKind {
         match self {
             SelfKind::Region(None, mutbl) => mutbl.ref_prefix_str().to_string(),
             SelfKind::Region(Some(lt), mutbl) => format!("&{lt} {}", mutbl.prefix_str()),
+            SelfKind::Pinned(None, mutbl) => format!("&pin {}", mutbl.ptr_str()),
+            SelfKind::Pinned(Some(lt), mutbl) => format!("&{lt} pin {}", mutbl.ptr_str()),
             SelfKind::Value(_) | SelfKind::Explicit(_, _) => {
                 unreachable!("if we had an explicit self, we wouldn't be here")
             }
@@ -2666,11 +2670,13 @@ impl Param {
             if ident.name == kw::SelfLower {
                 return match self.ty.kind {
                     TyKind::ImplicitSelf => Some(respan(self.pat.span, SelfKind::Value(mutbl))),
-                    TyKind::Ref(lt, MutTy { ref ty, mutbl })
-                    | TyKind::PinnedRef(lt, MutTy { ref ty, mutbl })
+                    TyKind::Ref(lt, MutTy { ref ty, mutbl }) if ty.kind.is_implicit_self() => {
+                        Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
+                    }
+                    TyKind::PinnedRef(lt, MutTy { ref ty, mutbl })
                         if ty.kind.is_implicit_self() =>
                     {
-                        Some(respan(self.pat.span, SelfKind::Region(lt, mutbl)))
+                        Some(respan(self.pat.span, SelfKind::Pinned(lt, mutbl)))
                     }
                     _ => Some(respan(
                         self.pat.span.to(self.ty.span),
@@ -2712,6 +2718,15 @@ impl Param {
                     tokens: None,
                 }),
             ),
+            SelfKind::Pinned(lt, mutbl) => (
+                mutbl,
+                P(Ty {
+                    id: DUMMY_NODE_ID,
+                    kind: TyKind::PinnedRef(lt, MutTy { ty: infer_ty, mutbl }),
+                    span,
+                    tokens: None,
+                }),
+            ),
         };
         Param {
             attrs,

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1783,6 +1783,13 @@ impl<'a> State<'a> {
                 self.print_mutability(*m, false);
                 self.word("self")
             }
+            SelfKind::Pinned(lt, m) => {
+                self.word("&");
+                self.print_opt_lifetime(lt);
+                self.word("pin ");
+                self.print_mutability(*m, true);
+                self.word("self")
+            }
             SelfKind::Explicit(typ, m) => {
                 self.print_mutability(*m, false);
                 self.word("self");

compiler/rustc_attr_parsing/src/parser.rs

@@ -473,6 +473,15 @@ impl<'a> MetaItemListParserContext<'a> {
         {
             self.inside_delimiters.next();
             return Some(MetaItemOrLitParser::Lit(lit));
+        } else if let Some(TokenTree::Delimited(.., Delimiter::Invisible(_), inner_tokens)) =
+            self.inside_delimiters.peek()
+        {
+            self.inside_delimiters.next();
+            return MetaItemListParserContext {
+                inside_delimiters: inner_tokens.iter().peekable(),
+                dcx: self.dcx,
+            }
+            .next();
         }
 
         // or a path.

compiler/rustc_borrowck/src/type_check/mod.rs

@@ -2120,8 +2120,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
                                 //
                                 // Note that other checks (such as denying `dyn Send` -> `dyn
                                 // Debug`) are in `rustc_hir_typeck`.
-                                if let ty::Dynamic(src_tty, _src_lt, _) = *src_tail.kind()
-                                    && let ty::Dynamic(dst_tty, dst_lt, _) = *dst_tail.kind()
+                                if let ty::Dynamic(src_tty, _src_lt, ty::Dyn) = *src_tail.kind()
+                                    && let ty::Dynamic(dst_tty, dst_lt, ty::Dyn) = *dst_tail.kind()
                                     && src_tty.principal().is_some()
                                     && dst_tty.principal().is_some()
                                 {

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -3382,6 +3382,35 @@ fn add_lld_args(
     // this, `wasm-component-ld`, which is overridden if this option is passed.
     if !sess.target.is_like_wasm {
         cmd.cc_arg("-fuse-ld=lld");
+
+        // On ELF platforms like at least x64 linux, GNU ld and LLD have opposite defaults on some
+        // section garbage-collection features. For example, the somewhat popular `linkme` crate and
+        // its dependents rely in practice on this difference: when using lld, they need `-z
+        // nostart-stop-gc` to prevent encapsulation symbols and sections from being
+        // garbage-collected.
+        //
+        // More information about all this can be found in:
+        // - https://maskray.me/blog/2021-01-31-metadata-sections-comdat-and-shf-link-order
+        // - https://lld.llvm.org/ELF/start-stop-gc
+        //
+        // So when using lld, we restore, for now, the traditional behavior to help migration, but
+        // will remove it in the future.
+        // Since this only disables an optimization, it shouldn't create issues, but is in theory
+        // slightly suboptimal. However, it:
+        // - doesn't have any visible impact on our benchmarks
+        // - reduces the need to disable lld for the crates that depend on this
+        //
+        // Note that lld can detect some cases where this difference is relied on, and emits a
+        // dedicated error to add this link arg. We could make use of this error to emit an FCW. As
+        // of writing this, we don't do it, because lld is already enabled by default on nightly
+        // without this mitigation: no working project would see the FCW, so we do this to help
+        // stabilization.
+        //
+        // FIXME: emit an FCW if linking fails due its absence, and then remove this link-arg in the
+        // future.
+        if sess.target.llvm_target == "x86_64-unknown-linux-gnu" {
+            cmd.link_arg("-znostart-stop-gc");
+        }
     }
 
     if !flavor.is_gnu() {

compiler/rustc_errors/src/lib.rs

@@ -626,7 +626,6 @@ pub enum StashKey {
     MaybeFruTypo,
     CallAssocMethod,
     AssociatedTypeSuggestion,
-    MaybeForgetReturn,
     /// Query cycle detected, stashing in favor of a better error.
     Cycle,
     UndeterminedMacroResolution,

compiler/rustc_feature/src/unstable.rs

@@ -1,6 +1,7 @@
 //! List of the unstable feature gates.
 
 use std::path::PathBuf;
+use std::time::{SystemTime, UNIX_EPOCH};
 
 use rustc_data_structures::fx::FxHashSet;
 use rustc_span::{Span, Symbol, sym};
@@ -685,11 +686,13 @@ impl Features {
     ) -> Result<(), Box<dyn std::error::Error>> {
         #[derive(serde::Serialize)]
         struct LibFeature {
+            timestamp: u128,
             symbol: String,
         }
 
         #[derive(serde::Serialize)]
         struct LangFeature {
+            timestamp: u128,
             symbol: String,
             since: Option<String>,
         }
@@ -703,10 +706,20 @@ impl Features {
         let metrics_file = std::fs::File::create(metrics_path)?;
         let metrics_file = std::io::BufWriter::new(metrics_file);
 
+        let now = || {
+            SystemTime::now()
+                .duration_since(UNIX_EPOCH)
+                .expect("system time should always be greater than the unix epoch")
+                .as_nanos()
+        };
+
         let lib_features = self
             .enabled_lib_features
             .iter()
-            .map(|EnabledLibFeature { gate_name, .. }| LibFeature { symbol: gate_name.to_string() })
+            .map(|EnabledLibFeature { gate_name, .. }| LibFeature {
+                symbol: gate_name.to_string(),
+                timestamp: now(),
+            })
             .collect();
 
         let lang_features = self
@@ -715,6 +728,7 @@ impl Features {
             .map(|EnabledLangFeature { gate_name, stable_since, .. }| LangFeature {
                 symbol: gate_name.to_string(),
                 since: stable_since.map(|since| since.to_string()),
+                timestamp: now(),
             })
             .collect();
 

compiler/rustc_hir_analysis/messages.ftl

@@ -620,6 +620,8 @@ hir_analysis_variances_of = {$variances}
 hir_analysis_where_clause_on_main = `main` function is not allowed to have a `where` clause
     .label = `main` cannot have a `where` clause
 
+hir_analysis_within_macro = due to this macro variable
+
 hir_analysis_wrong_number_of_generic_arguments_to_intrinsic =
     intrinsic has wrong number of {$descr} parameters: found {$found}, expected {$expected}
     .label = expected {$expected} {$descr} {$expected ->

compiler/rustc_hir_analysis/src/errors.rs

@@ -84,6 +84,8 @@ pub(crate) struct AssocItemNotFound<'a> {
     pub label: Option<AssocItemNotFoundLabel<'a>>,
     #[subdiagnostic]
     pub sugg: Option<AssocItemNotFoundSugg<'a>>,
+    #[label(hir_analysis_within_macro)]
+    pub within_macro_span: Option<Span>,
 }
 
 #[derive(Subdiagnostic)]

compiler/rustc_hir_analysis/src/hir_ty_lowering/errors.rs

@@ -151,6 +151,9 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
             qself: &qself_str,
             label: None,
             sugg: None,
+            // Try to get the span of the identifier within the path's syntax context
+            // (if that's different).
+            within_macro_span: assoc_name.span.within_macro(span, tcx.sess.source_map()),
         };
 
         if is_dummy {

compiler/rustc_hir_typeck/src/expr.rs

@@ -3069,7 +3069,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             "ban_nonexisting_field: field={:?}, base={:?}, expr={:?}, base_ty={:?}",
             ident, base, expr, base_ty
         );
-        let mut err = self.no_such_field_err(ident, base_ty, base.hir_id);
+        let mut err = self.no_such_field_err(ident, base_ty, expr);
 
         match *base_ty.peel_refs().kind() {
             ty::Array(_, len) => {
@@ -3282,29 +3282,38 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         );
     }
 
-    fn no_such_field_err(&self, field: Ident, expr_t: Ty<'tcx>, id: HirId) -> Diag<'_> {
+    fn no_such_field_err(
+        &self,
+        field: Ident,
+        base_ty: Ty<'tcx>,
+        expr: &hir::Expr<'tcx>,
+    ) -> Diag<'_> {
         let span = field.span;
-        debug!("no_such_field_err(span: {:?}, field: {:?}, expr_t: {:?})", span, field, expr_t);
+        debug!("no_such_field_err(span: {:?}, field: {:?}, expr_t: {:?})", span, field, base_ty);
 
-        let mut err = self.dcx().create_err(NoFieldOnType { span, ty: expr_t, field });
-        if expr_t.references_error() {
+        let mut err = self.dcx().create_err(NoFieldOnType { span, ty: base_ty, field });
+        if base_ty.references_error() {
             err.downgrade_to_delayed_bug();
         }
 
+        if let Some(within_macro_span) = span.within_macro(expr.span, self.tcx.sess.source_map()) {
+            err.span_label(within_macro_span, "due to this macro variable");
+        }
+
         // try to add a suggestion in case the field is a nested field of a field of the Adt
-        let mod_id = self.tcx.parent_module(id).to_def_id();
-        let (ty, unwrap) = if let ty::Adt(def, args) = expr_t.kind()
+        let mod_id = self.tcx.parent_module(expr.hir_id).to_def_id();
+        let (ty, unwrap) = if let ty::Adt(def, args) = base_ty.kind()
             && (self.tcx.is_diagnostic_item(sym::Result, def.did())
                 || self.tcx.is_diagnostic_item(sym::Option, def.did()))
             && let Some(arg) = args.get(0)
             && let Some(ty) = arg.as_type()
         {
             (ty, "unwrap().")
         } else {
-            (expr_t, "")
+            (base_ty, "")
         };
         for (found_fields, args) in
-            self.get_field_candidates_considering_privacy_for_diag(span, ty, mod_id, id)
+            self.get_field_candidates_considering_privacy_for_diag(span, ty, mod_id, expr.hir_id)
         {
             let field_names = found_fields.iter().map(|field| field.name).collect::<Vec<_>>();
             let mut candidate_fields: Vec<_> = found_fields
@@ -3317,7 +3326,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         args,
                         vec![],
                         mod_id,
-                        id,
+                        expr.hir_id,
                     )
                 })
                 .map(|mut field_path| {
@@ -3328,7 +3337,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             candidate_fields.sort();
 
             let len = candidate_fields.len();
-            if len > 0 {
+            // Don't suggest `.field` if the base expr is from a different
+            // syntax context than the field.
+            if len > 0 && expr.span.eq_ctxt(field.span) {
                 err.span_suggestions(
                     field.span.shrink_to_lo(),
                     format!(
@@ -3963,7 +3974,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 _ => (),
             };
 
-            self.no_such_field_err(field, container, expr.hir_id).emit();
+            self.no_such_field_err(field, container, expr).emit();
 
             break;
         }

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -669,12 +669,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
         if !errors.is_empty() {
             self.adjust_fulfillment_errors_for_expr_obligation(&mut errors);
-            let errors_causecode = errors
-                .iter()
-                .map(|e| (e.obligation.cause.span, e.root_obligation.cause.code().clone()))
-                .collect::<Vec<_>>();
             self.err_ctxt().report_fulfillment_errors(errors);
-            self.collect_unused_stmts_for_coerce_return_ty(errors_causecode);
         }
     }
 

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -3,9 +3,7 @@ use std::{fmt, iter, mem};
 use itertools::Itertools;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_errors::codes::*;
-use rustc_errors::{
-    Applicability, Diag, ErrorGuaranteed, MultiSpan, StashKey, a_or_an, listify, pluralize,
-};
+use rustc_errors::{Applicability, Diag, ErrorGuaranteed, MultiSpan, a_or_an, listify, pluralize};
 use rustc_hir::def::{CtorOf, DefKind, Res};
 use rustc_hir::def_id::DefId;
 use rustc_hir::intravisit::Visitor;
@@ -2193,62 +2191,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub(super) fn collect_unused_stmts_for_coerce_return_ty(
-        &self,
-        errors_causecode: Vec<(Span, ObligationCauseCode<'tcx>)>,
-    ) {
-        for (span, code) in errors_causecode {
-            self.dcx().try_steal_modify_and_emit_err(span, StashKey::MaybeForgetReturn, |err| {
-                if let Some(fn_sig) = self.body_fn_sig()
-                    && let ObligationCauseCode::WhereClauseInExpr(_, _, binding_hir_id, ..) = code
-                    && !fn_sig.output().is_unit()
-                {
-                    let mut block_num = 0;
-                    let mut found_semi = false;
-                    for (hir_id, node) in self.tcx.hir_parent_iter(binding_hir_id) {
-                        // Don't proceed into parent bodies
-                        if hir_id.owner != binding_hir_id.owner {
-                            break;
-                        }
-                        match node {
-                            hir::Node::Stmt(stmt) => {
-                                if let hir::StmtKind::Semi(expr) = stmt.kind {
-                                    let expr_ty = self.typeck_results.borrow().expr_ty(expr);
-                                    let return_ty = fn_sig.output();
-                                    if !matches!(expr.kind, hir::ExprKind::Ret(..))
-                                        && self.may_coerce(expr_ty, return_ty)
-                                    {
-                                        found_semi = true;
-                                    }
-                                }
-                            }
-                            hir::Node::Block(_block) => {
-                                if found_semi {
-                                    block_num += 1;
-                                }
-                            }
-                            hir::Node::Item(item) => {
-                                if let hir::ItemKind::Fn { .. } = item.kind {
-                                    break;
-                                }
-                            }
-                            _ => {}
-                        }
-                    }
-                    if block_num > 1 && found_semi {
-                        err.span_suggestion_verbose(
-                            // use the span of the *whole* expr
-                            self.tcx.hir().span(binding_hir_id).shrink_to_lo(),
-                            "you might have meant to return this to infer its type parameters",
-                            "return ",
-                            Applicability::MaybeIncorrect,
-                        );
-                    }
-                }
-            });
-        }
-    }
-
     /// Given a vector of fulfillment errors, try to adjust the spans of the
     /// errors to more accurately point at the cause of the failure.
     ///