Rollup of 12 pull requests

RELEASES.md

@@ -1,3 +1,88 @@
+Version 1.92.0 (2025-12-11)
+==========================
+
+<a id="1.92.0-Language"></a>
+
+Language
+--------
+- [Document `MaybeUninit` representation and validity](https://github.com/rust-lang/rust/pull/140463)
+- [Allow `&raw [mut | const]` for union field in safe code](https://github.com/rust-lang/rust/pull/141469)
+- [Prefer item bounds of associated types over where-bounds for auto-traits and `Sized`](https://github.com/rust-lang/rust/pull/144064)
+- [Do not materialize `X` in `[X; 0]` when `X` is unsizing a const](https://github.com/rust-lang/rust/pull/145277)
+- [Support combining `#[track_caller]` and `#[no_mangle]` (requires every declaration specifying `#[track_caller]` as well)](https://github.com/rust-lang/rust/pull/145724)
+- [Make never type lints `never_type_fallback_flowing_into_unsafe` and `dependency_on_unit_never_type_fallback` deny-by-default](https://github.com/rust-lang/rust/pull/146167)
+- [Allow specifying multiple bounds for same associated item, except in trait objects](https://github.com/rust-lang/rust/pull/146593)
+- [Slightly strengthen higher-ranked region handling in coherence](https://github.com/rust-lang/rust/pull/146725)
+- [The `unused_must_use` lint no longer warns on `Result<(), Uninhabited>` (for instance, `Result<(), !>`), or `ControlFlow<Uninhabited, ()>`](https://github.com/rust-lang/rust/pull/147382). This avoids having to check for an error that can never happen.
+
+<a id="1.92.0-Compiler"></a>
+
+Compiler
+--------
+- [Make `mips64el-unknown-linux-muslabi64` link dynamically](https://github.com/rust-lang/rust/pull/146858)
+- [Remove current code for embedding command-line args in PDB](https://github.com/rust-lang/rust/pull/147022)
+  Command-line information is typically not needed by debugging tools, and the removed code
+  was causing problems for incremental builds even on targets that don't use PDB debuginfo.
+
+<a id="1.92.0-Libraries"></a>
+
+Libraries
+---------
+- [Specialize `Iterator::eq{_by}` for `TrustedLen` iterators](https://github.com/rust-lang/rust/pull/137122)
+- [Simplify `Extend` for tuples](https://github.com/rust-lang/rust/pull/138799)
+- [Added details to `Debug` for `EncodeWide`](https://github.com/rust-lang/rust/pull/140153).
+- [`iter::Repeat::last`](https://github.com/rust-lang/rust/pull/147258) and [`count`](https://github.com/rust-lang/rust/pull/146410) will now panic, rather than looping infinitely.
+
+<a id="1.92.0-Stabilized-APIs"></a>
+
+Stabilized APIs
+---------------
+
+- [`NonZero<u{N}>::div_ceil`](https://doc.rust-lang.org/stable/std/num/struct.NonZero.html#method.div_ceil)
+- [`Location::file_as_c_str`](https://doc.rust-lang.org/stable/std/panic/struct.Location.html#method.file_as_c_str)
+- [`RwLockWriteGuard::downgrade`](https://doc.rust-lang.org/stable/std/sync/struct.RwLockWriteGuard.html#method.downgrade)
+- [`Box::new_zeroed`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed)
+- [`Box::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/boxed/struct.Box.html#method.new_zeroed_slice)
+- [`Rc::new_zeroed`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed)
+- [`Rc::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/rc/struct.Rc.html#method.new_zeroed_slice)
+- [`Arc::new_zeroed`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.new_zeroed)
+- [`Arc::new_zeroed_slice`](https://doc.rust-lang.org/stable/std/sync/struct.Arc.html#method.new_zeroed_slice)
+- [`btree_map::Entry::insert_entry`](https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html#method.insert_entry)
+- [`btree_map::VacantEntry::insert_entry`](https://doc.rust-lang.org/stable/std/collections/btree_map/struct.VacantEntry.html#method.insert_entry)
+- [`impl Extend<proc_macro::Group> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CGroup%3E-for-TokenStream)
+- [`impl Extend<proc_macro::Literal> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CLiteral%3E-for-TokenStream)
+- [`impl Extend<proc_macro::Punct> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CPunct%3E-for-TokenStream)
+- [`impl Extend<proc_macro::Ident> for proc_macro::TokenStream`](https://doc.rust-lang.org/stable/proc_macro/struct.TokenStream.html#impl-Extend%3CIdent%3E-for-TokenStream)
+
+These previously stable APIs are now stable in const contexts:
+
+- [`<[_]>::rotate_left`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.rotate_left)
+- [`<[_]>::rotate_right`](https://doc.rust-lang.org/stable/std/primitive.slice.html#method.rotate_right)
+
+<a id="1.92.0-Cargo"></a>
+
+Cargo
+-----
+- [Added a new chapter](https://github.com/rust-lang/cargo/issues/16119) to the Cargo book, ["Optimizing Build Performance"](https://doc.rust-lang.org/stable/cargo/guide/build-performance.html).
+
+<a id="1.92.0-Rustdoc"></a>
+
+Rustdoc
+-----
+- [If a trait item appears in rustdoc search, hide the corresponding impl items](https://github.com/rust-lang/rust/pull/145898).  Previously a search for "last" would show both `Iterator::last` as well as impl methods like `std::vec::IntoIter::last`.  Now these impl methods will be hidden, freeing up space for inherent methods like `BTreeSet::last`.
+- [Relax rules for identifiers in search](https://github.com/rust-lang/rust/pull/147860).  Previously you could only search for identifiers that were valid in rust code, now searches only need to be valid as part of an identifier.  For example, you can now perform a search that starts with a digit.
+
+<a id="1.92.0-Compatibility-Notes"></a>
+
+Compatibility Notes
+-------------------
+* [Fix backtraces with `-C panic=abort` on Linux by generating unwind tables by default](https://github.com/rust-lang/rust/pull/143613). Build with `-C force-unwind-tables=no` to keep omitting unwind tables.
+- As part of the larger effort refactoring compiler built-in attributes and their diagnostics, [the future-compatibility lint `invalid_macro_export_arguments` is upgraded to deny-by-default and will be reported in dependencies too.](https://github.com/rust-lang/rust/pull/143857)
+- [Update the minimum external LLVM to 20](https://github.com/rust-lang/rust/pull/145071)
+- [Prevent downstream `impl DerefMut for Pin<LocalType>`](https://github.com/rust-lang/rust/pull/145608)
+- [Don't apply temporary lifetime extension rules to the arguments of non-extended `pin!` and formatting macros](https://github.com/rust-lang/rust/pull/145838)
+
+
 Version 1.91.1 (2025-11-10)
 ===========================
 

compiler/rustc_ast_lowering/src/delegation.rs

@@ -44,6 +44,7 @@ use hir::{BodyId, HirId};
 use rustc_abi::ExternAbi;
 use rustc_ast::*;
 use rustc_errors::ErrorGuaranteed;
+use rustc_hir::attrs::{AttributeKind, InlineAttr};
 use rustc_hir::def_id::DefId;
 use rustc_middle::span_bug;
 use rustc_middle::ty::{Asyncness, ResolverAstLowering};
@@ -87,6 +88,8 @@ impl<'hir> LoweringContext<'_, 'hir> {
         let sig_id = self.get_delegation_sig_id(item_id, delegation.id, span, is_in_trait_impl);
         match sig_id {
             Ok(sig_id) => {
+                self.add_inline_attribute_if_needed(span);
+
                 let is_method = self.is_method(sig_id, span);
                 let (param_count, c_variadic) = self.param_count(sig_id);
                 let decl = self.lower_delegation_decl(sig_id, param_count, c_variadic, span);
@@ -100,6 +103,31 @@ impl<'hir> LoweringContext<'_, 'hir> {
         }
     }
 
+    fn add_inline_attribute_if_needed(&mut self, span: Span) {
+        const PARENT_ID: hir::ItemLocalId = hir::ItemLocalId::ZERO;
+        let create_inline_attr_slice =
+            || [hir::Attribute::Parsed(AttributeKind::Inline(InlineAttr::Hint, span))];
+
+        let new_attributes = match self.attrs.get(&PARENT_ID) {
+            Some(attrs) => {
+                // Check if reuse already specifies any inline attribute, if so, do nothing
+                if attrs
+                    .iter()
+                    .any(|a| matches!(a, hir::Attribute::Parsed(AttributeKind::Inline(..))))
+                {
+                    return;
+                }
+
+                self.arena.alloc_from_iter(
+                    attrs.into_iter().map(|a| a.clone()).chain(create_inline_attr_slice()),
+                )
+            }
+            None => self.arena.alloc_from_iter(create_inline_attr_slice()),
+        };
+
+        self.attrs.insert(PARENT_ID, new_attributes);
+    }
+
     fn get_delegation_sig_id(
         &self,
         item_id: NodeId,

compiler/rustc_ast_lowering/src/lib.rs

@@ -1677,7 +1677,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         let output = match coro {
             Some(coro) => {
                 let fn_def_id = self.local_def_id(fn_node_id);
-                self.lower_coroutine_fn_ret_ty(&decl.output, fn_def_id, coro, kind, fn_span)
+                self.lower_coroutine_fn_ret_ty(&decl.output, fn_def_id, coro, kind)
             }
             None => match &decl.output {
                 FnRetTy::Ty(ty) => {
@@ -1762,9 +1762,8 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         fn_def_id: LocalDefId,
         coro: CoroutineKind,
         fn_kind: FnDeclKind,
-        fn_span: Span,
     ) -> hir::FnRetTy<'hir> {
-        let span = self.lower_span(fn_span);
+        let span = self.lower_span(output.span());
 
         let (opaque_ty_node_id, allowed_features) = match coro {
             CoroutineKind::Async { return_impl_trait_id, .. } => (return_impl_trait_id, None),

compiler/rustc_attr_parsing/src/attributes/cfg.rs

@@ -2,16 +2,16 @@ use std::convert::identity;
 
 use rustc_ast::token::Delimiter;
 use rustc_ast::tokenstream::DelimSpan;
-use rustc_ast::{AttrItem, Attribute, CRATE_NODE_ID, LitKind, NodeId, ast, token};
+use rustc_ast::{AttrItem, Attribute, CRATE_NODE_ID, LitKind, ast, token};
 use rustc_errors::{Applicability, PResult};
 use rustc_feature::{AttrSuggestionStyle, AttributeTemplate, Features, template};
 use rustc_hir::attrs::CfgEntry;
+use rustc_hir::lints::AttributeLintKind;
 use rustc_hir::{AttrPath, RustcVersion};
 use rustc_parse::parser::{ForceCollect, Parser};
 use rustc_parse::{exp, parse_in};
 use rustc_session::Session;
 use rustc_session::config::ExpectedValues;
-use rustc_session::lint::BuiltinLintDiag;
 use rustc_session::lint::builtin::UNEXPECTED_CFGS;
 use rustc_session::parse::{ParseSess, feature_err};
 use rustc_span::{ErrorGuaranteed, Span, Symbol, sym};
@@ -23,10 +23,7 @@ use crate::session_diagnostics::{
     AttributeParseError, AttributeParseErrorReason, CfgAttrBadDelim, MetaBadDelimSugg,
     ParsedDescription,
 };
-use crate::{
-    AttributeParser, CfgMatchesLintEmitter, fluent_generated, parse_version, session_diagnostics,
-    try_gate_cfg,
-};
+use crate::{AttributeParser, fluent_generated, parse_version, session_diagnostics, try_gate_cfg};
 
 pub const CFG_TEMPLATE: AttributeTemplate = template!(
     List: &["predicate"],
@@ -195,43 +192,46 @@ fn parse_name_value<S: Stage>(
         }
     };
 
-    Ok(CfgEntry::NameValue { name, name_span, value, span })
+    match cx.sess.psess.check_config.expecteds.get(&name) {
+        Some(ExpectedValues::Some(values)) if !values.contains(&value.map(|(v, _)| v)) => cx
+            .emit_lint(
+                UNEXPECTED_CFGS,
+                AttributeLintKind::UnexpectedCfgValue((name, name_span), value),
+                span,
+            ),
+        None if cx.sess.psess.check_config.exhaustive_names => cx.emit_lint(
+            UNEXPECTED_CFGS,
+            AttributeLintKind::UnexpectedCfgName((name, name_span), value),
+            span,
+        ),
+        _ => { /* not unexpected */ }
+    }
+
+    Ok(CfgEntry::NameValue { name, value: value.map(|(v, _)| v), span })
 }
 
-pub fn eval_config_entry(
-    sess: &Session,
-    cfg_entry: &CfgEntry,
-    id: NodeId,
-    emit_lints: ShouldEmit,
-) -> EvalConfigResult {
+pub fn eval_config_entry(sess: &Session, cfg_entry: &CfgEntry) -> EvalConfigResult {
     match cfg_entry {
         CfgEntry::All(subs, ..) => {
-            let mut all = None;
             for sub in subs {
-                let res = eval_config_entry(sess, sub, id, emit_lints);
-                // We cannot short-circuit because `eval_config_entry` emits some lints
+                let res = eval_config_entry(sess, sub);
                 if !res.as_bool() {
-                    all.get_or_insert(res);
+                    return res;
                 }
             }
-            all.unwrap_or_else(|| EvalConfigResult::True)
+            EvalConfigResult::True
         }
         CfgEntry::Any(subs, span) => {
-            let mut any = None;
             for sub in subs {
-                let res = eval_config_entry(sess, sub, id, emit_lints);
-                // We cannot short-circuit because `eval_config_entry` emits some lints
+                let res = eval_config_entry(sess, sub);
                 if res.as_bool() {
-                    any.get_or_insert(res);
+                    return res;
                 }
             }
-            any.unwrap_or_else(|| EvalConfigResult::False {
-                reason: cfg_entry.clone(),
-                reason_span: *span,
-            })
+            EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
         }
         CfgEntry::Not(sub, span) => {
-            if eval_config_entry(sess, sub, id, emit_lints).as_bool() {
+            if eval_config_entry(sess, sub).as_bool() {
                 EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
             } else {
                 EvalConfigResult::True
@@ -244,32 +244,8 @@ pub fn eval_config_entry(
                 EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }
             }
         }
-        CfgEntry::NameValue { name, name_span, value, span } => {
-            if let ShouldEmit::ErrorsAndLints = emit_lints {
-                match sess.psess.check_config.expecteds.get(name) {
-                    Some(ExpectedValues::Some(values))
-                        if !values.contains(&value.map(|(v, _)| v)) =>
-                    {
-                        id.emit_span_lint(
-                            sess,
-                            UNEXPECTED_CFGS,
-                            *span,
-                            BuiltinLintDiag::UnexpectedCfgValue((*name, *name_span), *value),
-                        );
-                    }
-                    None if sess.psess.check_config.exhaustive_names => {
-                        id.emit_span_lint(
-                            sess,
-                            UNEXPECTED_CFGS,
-                            *span,
-                            BuiltinLintDiag::UnexpectedCfgName((*name, *name_span), *value),
-                        );
-                    }
-                    _ => { /* not unexpected */ }
-                }
-            }
-
-            if sess.psess.config.contains(&(*name, value.map(|(v, _)| v))) {
+        CfgEntry::NameValue { name, value, span } => {
+            if sess.psess.config.contains(&(*name, *value)) {
                 EvalConfigResult::True
             } else {
                 EvalConfigResult::False { reason: cfg_entry.clone(), reason_span: *span }

compiler/rustc_attr_parsing/src/attributes/cfg_old.rs

@@ -2,6 +2,7 @@ use rustc_ast::{LitKind, MetaItem, MetaItemInner, MetaItemKind, MetaItemLit, Nod
 use rustc_ast_pretty::pprust;
 use rustc_feature::{Features, GatedCfg, find_gated_cfg};
 use rustc_hir::RustcVersion;
+use rustc_hir::lints::AttributeLintKind;
 use rustc_session::Session;
 use rustc_session::config::ExpectedValues;
 use rustc_session::lint::builtin::UNEXPECTED_CFGS;
@@ -51,21 +52,21 @@ pub fn cfg_matches(
                     sess,
                     UNEXPECTED_CFGS,
                     cfg.span,
-                    BuiltinLintDiag::UnexpectedCfgValue(
+                    BuiltinLintDiag::AttributeLint(AttributeLintKind::UnexpectedCfgValue(
                         (cfg.name, cfg.name_span),
                         cfg.value.map(|v| (v, cfg.value_span.unwrap())),
-                    ),
+                    )),
                 );
             }
             None if sess.psess.check_config.exhaustive_names => {
                 lint_emitter.emit_span_lint(
                     sess,
                     UNEXPECTED_CFGS,
                     cfg.span,
-                    BuiltinLintDiag::UnexpectedCfgName(
+                    BuiltinLintDiag::AttributeLint(AttributeLintKind::UnexpectedCfgName(
                         (cfg.name, cfg.name_span),
                         cfg.value.map(|v| (v, cfg.value_span.unwrap())),
-                    ),
+                    )),
                 );
             }
             _ => { /* not unexpected */ }

compiler/rustc_builtin_macros/src/cfg.rs

@@ -26,13 +26,7 @@ pub(crate) fn expand_cfg(
 
     ExpandResult::Ready(match parse_cfg(cx, sp, tts) {
         Ok(cfg) => {
-            let matches_cfg = attr::eval_config_entry(
-                cx.sess,
-                &cfg,
-                cx.current_expansion.lint_node_id,
-                ShouldEmit::ErrorsAndLints,
-            )
-            .as_bool();
+            let matches_cfg = attr::eval_config_entry(cx.sess, &cfg).as_bool();
 
             MacEager::expr(cx.expr_bool(sp, matches_cfg))
         }

compiler/rustc_builtin_macros/src/cfg_select.rs

@@ -1,7 +1,7 @@
 use rustc_ast::tokenstream::TokenStream;
 use rustc_attr_parsing as attr;
 use rustc_attr_parsing::{
-    CfgSelectBranches, CfgSelectPredicate, EvalConfigResult, ShouldEmit, parse_cfg_select,
+    CfgSelectBranches, CfgSelectPredicate, EvalConfigResult, parse_cfg_select,
 };
 use rustc_expand::base::{DummyResult, ExpandResult, ExtCtxt, MacroExpanderResult};
 use rustc_span::{Ident, Span, sym};
@@ -10,21 +10,13 @@ use crate::errors::{CfgSelectNoMatches, CfgSelectUnreachable};
 
 /// Selects the first arm whose predicate evaluates to true.
 fn select_arm(ecx: &ExtCtxt<'_>, branches: CfgSelectBranches) -> Option<(TokenStream, Span)> {
-    let mut result = None;
     for (cfg, tt, arm_span) in branches.reachable {
-        if let EvalConfigResult::True = attr::eval_config_entry(
-            &ecx.sess,
-            &cfg,
-            ecx.current_expansion.lint_node_id,
-            ShouldEmit::ErrorsAndLints,
-        ) {
-            // FIXME(#149215) Ideally we should short-circuit here, but `eval_config_entry` currently emits lints so we cannot do this yet.
-            result.get_or_insert((tt, arm_span));
+        if let EvalConfigResult::True = attr::eval_config_entry(&ecx.sess, &cfg) {
+            return Some((tt, arm_span));
         }
     }
 
-    let wildcard = branches.wildcard.map(|(_, tt, span)| (tt, span));
-    result.or(wildcard)
+    branches.wildcard.map(|(_, tt, span)| (tt, span))
 }
 
 pub(super) fn expand_cfg_select<'cx>(

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -13,8 +13,7 @@ use find_msvc_tools;
 use itertools::Itertools;
 use regex::Regex;
 use rustc_arena::TypedArena;
-use rustc_ast::CRATE_NODE_ID;
-use rustc_attr_parsing::{ShouldEmit, eval_config_entry};
+use rustc_attr_parsing::eval_config_entry;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_data_structures::memmap::Mmap;
 use rustc_data_structures::temp_dir::MaybeTempDir;
@@ -3029,9 +3028,7 @@ fn add_dynamic_crate(cmd: &mut dyn Linker, sess: &Session, cratepath: &Path) {
 
 fn relevant_lib(sess: &Session, lib: &NativeLib) -> bool {
     match lib.cfg {
-        Some(ref cfg) => {
-            eval_config_entry(sess, cfg, CRATE_NODE_ID, ShouldEmit::ErrorsAndLints).as_bool()
-        }
+        Some(ref cfg) => eval_config_entry(sess, cfg).as_bool(),
         None => true,
     }
 }