Rollup of 6 pull requests

compiler/rustc_codegen_llvm/src/attributes.rs

@@ -419,7 +419,10 @@ pub(crate) fn llfn_attrs_from_instance<'ll, 'tcx>(
                 if bti {
                     to_add.push(llvm::CreateAttrString(cx.llcx, "branch-target-enforcement"));
                 }
-                if let Some(PacRet { leaf, key }) = pac_ret {
+                if let Some(PacRet { leaf, pc, key }) = pac_ret {
+                    if pc {
+                        to_add.push(llvm::CreateAttrString(cx.llcx, "branch-protection-pauth-lr"));
+                    }
                     to_add.push(llvm::CreateAttrStringValue(
                         cx.llcx,
                         "sign-return-address",

compiler/rustc_codegen_llvm/src/context.rs

@@ -308,7 +308,13 @@ pub(crate) unsafe fn create_module<'ll>(
                 "sign-return-address",
                 pac_ret.is_some().into(),
             );
-            let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, key: PAuthKey::A });
+            let pac_opts = pac_ret.unwrap_or(PacRet { leaf: false, pc: false, key: PAuthKey::A });
+            llvm::add_module_flag_u32(
+                llmod,
+                llvm::ModuleFlagMergeBehavior::Min,
+                "branch-protection-pauth-lr",
+                pac_opts.pc.into(),
+            );
             llvm::add_module_flag_u32(
                 llmod,
                 llvm::ModuleFlagMergeBehavior::Min,

compiler/rustc_interface/src/tests.rs

@@ -764,7 +764,7 @@ fn test_unstable_options_tracking_hash() {
         branch_protection,
         Some(BranchProtection {
             bti: true,
-            pac_ret: Some(PacRet { leaf: true, key: PAuthKey::B })
+            pac_ret: Some(PacRet { leaf: true, pc: true, key: PAuthKey::B })
         })
     );
     tracked!(codegen_backend, Some("abc".to_string()));

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -459,7 +459,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             return (err, Vec::new());
         }
 
-        let (found, mut candidates) = self.try_lookup_name_relaxed(
+        let (found, suggested_candidates, mut candidates) = self.try_lookup_name_relaxed(
             &mut err,
             source,
             path,
@@ -478,7 +478,15 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         }
 
         let mut fallback = self.suggest_trait_and_bounds(&mut err, source, res, span, &base_error);
-        fallback |= self.suggest_typo(&mut err, source, path, following_seg, span, &base_error);
+        fallback |= self.suggest_typo(
+            &mut err,
+            source,
+            path,
+            following_seg,
+            span,
+            &base_error,
+            suggested_candidates,
+        );
 
         if fallback {
             // Fallback label.
@@ -589,7 +597,16 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         span: Span,
         res: Option<Res>,
         base_error: &BaseError,
-    ) -> (bool, Vec<ImportSuggestion>) {
+    ) -> (bool, FxHashSet<String>, Vec<ImportSuggestion>) {
+        let span = match following_seg {
+            Some(_) if path[0].ident.span.eq_ctxt(path[path.len() - 1].ident.span) => {
+                // The path `span` that comes in includes any following segments, which we don't
+                // want to replace in the suggestions.
+                path[0].ident.span.to(path[path.len() - 1].ident.span)
+            }
+            _ => span,
+        };
+        let mut suggested_candidates = FxHashSet::default();
         // Try to lookup name in more relaxed fashion for better error reporting.
         let ident = path.last().unwrap().ident;
         let is_expected = &|res| source.is_expected(res);
@@ -646,6 +663,11 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                 };
                 let msg = format!("{preamble}try using the variant's enum");
 
+                suggested_candidates.extend(
+                    enum_candidates
+                        .iter()
+                        .map(|(_variant_path, enum_ty_path)| enum_ty_path.clone()),
+                );
                 err.span_suggestions(
                     span,
                     msg,
@@ -658,7 +680,8 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         // Try finding a suitable replacement.
         let typo_sugg = self
             .lookup_typo_candidate(path, following_seg, source.namespace(), is_expected)
-            .to_opt_suggestion();
+            .to_opt_suggestion()
+            .filter(|sugg| !suggested_candidates.contains(sugg.candidate.as_str()));
         if let [segment] = path
             && !matches!(source, PathSource::Delegation)
             && self.self_type_is_available()
@@ -719,7 +742,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                     }
                 }
                 self.r.add_typo_suggestion(err, typo_sugg, ident_span);
-                return (true, candidates);
+                return (true, suggested_candidates, candidates);
             }
 
             // If the first argument in call is `self` suggest calling a method.
@@ -737,7 +760,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                     format!("self.{path_str}({args_snippet})"),
                     Applicability::MachineApplicable,
                 );
-                return (true, candidates);
+                return (true, suggested_candidates, candidates);
             }
         }
 
@@ -754,7 +777,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             ) {
                 // We do this to avoid losing a secondary span when we override the main error span.
                 self.r.add_typo_suggestion(err, typo_sugg, ident_span);
-                return (true, candidates);
+                return (true, suggested_candidates, candidates);
             }
         }
 
@@ -772,7 +795,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
                         ident.span,
                         format!("the binding `{path_str}` is available in a different scope in the same function"),
                     );
-                    return (true, candidates);
+                    return (true, suggested_candidates, candidates);
                 }
             }
         }
@@ -781,7 +804,7 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             candidates = self.smart_resolve_partial_mod_path_errors(path, following_seg);
         }
 
-        (false, candidates)
+        (false, suggested_candidates, candidates)
     }
 
     fn suggest_trait_and_bounds(
@@ -869,13 +892,16 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
         following_seg: Option<&Segment>,
         span: Span,
         base_error: &BaseError,
+        suggested_candidates: FxHashSet<String>,
     ) -> bool {
         let is_expected = &|res| source.is_expected(res);
         let ident_span = path.last().map_or(span, |ident| ident.ident.span);
         let typo_sugg =
             self.lookup_typo_candidate(path, following_seg, source.namespace(), is_expected);
         let mut fallback = false;
-        let typo_sugg = typo_sugg.to_opt_suggestion();
+        let typo_sugg = typo_sugg
+            .to_opt_suggestion()
+            .filter(|sugg| !suggested_candidates.contains(sugg.candidate.as_str()));
         if !self.r.add_typo_suggestion(err, typo_sugg, ident_span) {
             fallback = true;
             match self.diag_metadata.current_let_binding {
@@ -894,10 +920,13 @@ impl<'ast, 'ra: 'ast, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
 
             // If the trait has a single item (which wasn't matched by the algorithm), suggest it
             let suggestion = self.get_single_associated_item(path, &source, is_expected);
-            if !self.r.add_typo_suggestion(err, suggestion, ident_span) {
-                fallback = !self.let_binding_suggestion(err, ident_span);
-            }
+            self.r.add_typo_suggestion(err, suggestion, ident_span);
         }
+
+        if self.let_binding_suggestion(err, ident_span) {
+            fallback = false;
+        }
+
         fallback
     }
 

compiler/rustc_session/src/config.rs

@@ -1320,6 +1320,7 @@ pub enum PAuthKey {
 #[derive(Clone, Copy, Hash, Debug, PartialEq)]
 pub struct PacRet {
     pub leaf: bool,
+    pub pc: bool,
     pub key: PAuthKey,
 }
 

compiler/rustc_session/src/options.rs

@@ -442,8 +442,7 @@ mod desc {
     pub(crate) const parse_polonius: &str = "either no value or `legacy` (the default), or `next`";
     pub(crate) const parse_stack_protector: &str =
         "one of (`none` (default), `basic`, `strong`, or `all`)";
-    pub(crate) const parse_branch_protection: &str =
-        "a `,` separated combination of `bti`, `b-key`, `pac-ret`, or `leaf`";
+    pub(crate) const parse_branch_protection: &str = "a `,` separated combination of `bti`, `pac-ret`, followed by a combination of `pc`, `b-key`, or `leaf`";
     pub(crate) const parse_proc_macro_execution_strategy: &str =
         "one of supported execution strategies (`same-thread`, or `cross-thread`)";
     pub(crate) const parse_remap_path_scope: &str =
@@ -1401,7 +1400,7 @@ pub mod parse {
                     match opt {
                         "bti" => slot.bti = true,
                         "pac-ret" if slot.pac_ret.is_none() => {
-                            slot.pac_ret = Some(PacRet { leaf: false, key: PAuthKey::A })
+                            slot.pac_ret = Some(PacRet { leaf: false, pc: false, key: PAuthKey::A })
                         }
                         "leaf" => match slot.pac_ret.as_mut() {
                             Some(pac) => pac.leaf = true,
@@ -1411,6 +1410,10 @@ pub mod parse {
                             Some(pac) => pac.key = PAuthKey::B,
                             _ => return false,
                         },
+                        "pc" => match slot.pac_ret.as_mut() {
+                            Some(pac) => pac.pc = true,
+                            _ => return false,
+                        },
                         _ => return false,
                     };
                 }

library/core/src/cell.rs

@@ -2122,7 +2122,6 @@ impl<T: ?Sized> UnsafeCell<T> {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(unsafe_cell_from_mut)]
     /// use std::cell::UnsafeCell;
     ///
     /// let mut val = 42;
@@ -2132,7 +2131,9 @@ impl<T: ?Sized> UnsafeCell<T> {
     /// assert_eq!(*uc.get_mut(), 41);
     /// ```
     #[inline(always)]
-    #[unstable(feature = "unsafe_cell_from_mut", issue = "111645")]
+    #[stable(feature = "unsafe_cell_from_mut", since = "CURRENT_RUSTC_VERSION")]
+    #[rustc_const_stable(feature = "unsafe_cell_from_mut", since = "CURRENT_RUSTC_VERSION")]
+    #[cfg_attr(bootstrap, rustc_allow_const_fn_unstable(const_mut_refs))]
     pub const fn from_mut(value: &mut T) -> &mut UnsafeCell<T> {
         // SAFETY: `UnsafeCell<T>` has the same memory layout as `T` due to #[repr(transparent)].
         unsafe { &mut *(value as *mut T as *mut UnsafeCell<T>) }

library/core/src/char/methods.rs

@@ -1,7 +1,7 @@
 //! impl char {}
 
 use super::*;
-use crate::macros::const_panic;
+use crate::panic::const_panic;
 use crate::slice;
 use crate::str::from_utf8_unchecked_mut;
 use crate::unicode::printable::is_printable;

library/core/src/ffi/c_str.rs

@@ -3,11 +3,12 @@
 use crate::cmp::Ordering;
 use crate::error::Error;
 use crate::ffi::c_char;
+use crate::intrinsics::const_eval_select;
 use crate::iter::FusedIterator;
 use crate::marker::PhantomData;
 use crate::ptr::NonNull;
 use crate::slice::memchr;
-use crate::{fmt, intrinsics, ops, slice, str};
+use crate::{fmt, ops, slice, str};
 
 // FIXME: because this is doc(inline)d, we *have* to use intra-doc links because the actual link
 //   depends on where the item is being documented. however, since this is libcore, we can't
@@ -411,37 +412,35 @@ impl CStr {
     #[rustc_const_stable(feature = "const_cstr_unchecked", since = "1.59.0")]
     #[rustc_allow_const_fn_unstable(const_eval_select)]
     pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr {
-        #[inline]
-        fn rt_impl(bytes: &[u8]) -> &CStr {
-            // Chance at catching some UB at runtime with debug builds.
-            debug_assert!(!bytes.is_empty() && bytes[bytes.len() - 1] == 0);
-
-            // SAFETY: Casting to CStr is safe because its internal representation
-            // is a [u8] too (safe only inside std).
-            // Dereferencing the obtained pointer is safe because it comes from a
-            // reference. Making a reference is then safe because its lifetime
-            // is bound by the lifetime of the given `bytes`.
-            unsafe { &*(bytes as *const [u8] as *const CStr) }
-        }
-
-        const fn const_impl(bytes: &[u8]) -> &CStr {
-            // Saturating so that an empty slice panics in the assert with a good
-            // message, not here due to underflow.
-            let mut i = bytes.len().saturating_sub(1);
-            assert!(!bytes.is_empty() && bytes[i] == 0, "input was not nul-terminated");
-
-            // Ending nul byte exists, skip to the rest.
-            while i != 0 {
-                i -= 1;
-                let byte = bytes[i];
-                assert!(byte != 0, "input contained interior nul");
+        const_eval_select!(
+            @capture { bytes: &[u8] } -> &CStr:
+            if const {
+                // Saturating so that an empty slice panics in the assert with a good
+                // message, not here due to underflow.
+                let mut i = bytes.len().saturating_sub(1);
+                assert!(!bytes.is_empty() && bytes[i] == 0, "input was not nul-terminated");
+
+                // Ending nul byte exists, skip to the rest.
+                while i != 0 {
+                    i -= 1;
+                    let byte = bytes[i];
+                    assert!(byte != 0, "input contained interior nul");
+                }
+
+                // SAFETY: See runtime cast comment below.
+                unsafe { &*(bytes as *const [u8] as *const CStr) }
+            } else {
+                // Chance at catching some UB at runtime with debug builds.
+                debug_assert!(!bytes.is_empty() && bytes[bytes.len() - 1] == 0);
+
+                // SAFETY: Casting to CStr is safe because its internal representation
+                // is a [u8] too (safe only inside std).
+                // Dereferencing the obtained pointer is safe because it comes from a
+                // reference. Making a reference is then safe because its lifetime
+                // is bound by the lifetime of the given `bytes`.
+                unsafe { &*(bytes as *const [u8] as *const CStr) }
             }
-
-            // SAFETY: See `rt_impl` cast.
-            unsafe { &*(bytes as *const [u8] as *const CStr) }
-        }
-
-        intrinsics::const_eval_select((bytes,), const_impl, rt_impl)
+        )
     }
 
     /// Returns the inner pointer to this C string.
@@ -735,29 +734,27 @@ impl AsRef<CStr> for CStr {
 #[cfg_attr(bootstrap, rustc_const_stable(feature = "const_cstr_from_ptr", since = "1.81.0"))]
 #[rustc_allow_const_fn_unstable(const_eval_select)]
 const unsafe fn strlen(ptr: *const c_char) -> usize {
-    const fn strlen_ct(s: *const c_char) -> usize {
-        let mut len = 0;
-
-        // SAFETY: Outer caller has provided a pointer to a valid C string.
-        while unsafe { *s.add(len) } != 0 {
-            len += 1;
-        }
+    const_eval_select!(
+        @capture { s: *const c_char = ptr } -> usize:
+        if const {
+            let mut len = 0;
+
+            // SAFETY: Outer caller has provided a pointer to a valid C string.
+            while unsafe { *s.add(len) } != 0 {
+                len += 1;
+            }
 
-        len
-    }
+            len
+        } else {
+            extern "C" {
+                /// Provided by libc or compiler_builtins.
+                fn strlen(s: *const c_char) -> usize;
+            }
 
-    #[inline]
-    fn strlen_rt(s: *const c_char) -> usize {
-        extern "C" {
-            /// Provided by libc or compiler_builtins.
-            fn strlen(s: *const c_char) -> usize;
+            // SAFETY: Outer caller has provided a pointer to a valid C string.
+            unsafe { strlen(s) }
         }
-
-        // SAFETY: Outer caller has provided a pointer to a valid C string.
-        unsafe { strlen(s) }
-    }
-
-    intrinsics::const_eval_select((ptr,), strlen_ct, strlen_rt)
+    )
 }
 
 /// An iterator over the bytes of a [`CStr`], without the nul terminator.