Rollup of 5 pull requests

compiler/rustc_data_structures/src/flock.rs

@@ -9,6 +9,10 @@ cfg_match! {
         mod linux;
         use linux as imp;
     }
+    cfg(target_os = "redox") => {
+        mod linux;
+        use linux as imp;
+    }
     cfg(unix) => {
         mod unix;
         use unix as imp;

compiler/rustc_lint/messages.ftl

@@ -550,6 +550,7 @@ lint_non_local_definitions_impl = non-local `impl` definition, `impl` blocks sho
     .bounds = `impl` may be usable in bounds, etc. from outside the expression, which might e.g. make something constructible that previously wasn't, because it's still on a publicly-visible type
     .exception = items in an anonymous const item (`const _: () = {"{"} ... {"}"}`) are treated as in the same scope as the anonymous const's declaration
     .const_anon = use a const-anon item to suppress this lint
+    .macro_to_change = the {$macro_kind} `{$macro_to_change}` defines the non-local `impl`, and may need to be changed
 
 lint_non_local_definitions_impl_move_help =
     move the `impl` block outside of this {$body_kind_descr} {$depth ->

compiler/rustc_lint/src/lints.rs

@@ -1362,6 +1362,7 @@ pub enum NonLocalDefinitionsDiag {
         has_trait: bool,
         self_ty_str: String,
         of_trait_str: Option<String>,
+        macro_to_change: Option<(String, &'static str)>,
     },
     MacroRules {
         depth: u32,
@@ -1387,6 +1388,7 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                 has_trait,
                 self_ty_str,
                 of_trait_str,
+                macro_to_change,
             } => {
                 diag.primary_message(fluent::lint_non_local_definitions_impl);
                 diag.arg("depth", depth);
@@ -1397,6 +1399,15 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                     diag.arg("of_trait_str", of_trait_str);
                 }
 
+                if let Some((macro_to_change, macro_kind)) = macro_to_change {
+                    diag.arg("macro_to_change", macro_to_change);
+                    diag.arg("macro_kind", macro_kind);
+                    diag.note(fluent::lint_macro_to_change);
+                }
+                if let Some(cargo_update) = cargo_update {
+                    diag.subdiagnostic(&diag.dcx, cargo_update);
+                }
+
                 if has_trait {
                     diag.note(fluent::lint_bounds);
                     diag.note(fluent::lint_with_trait);
@@ -1422,9 +1433,6 @@ impl<'a> LintDiagnostic<'a, ()> for NonLocalDefinitionsDiag {
                     );
                 }
 
-                if let Some(cargo_update) = cargo_update {
-                    diag.subdiagnostic(&diag.dcx, cargo_update);
-                }
                 if let Some(const_anon) = const_anon {
                     diag.note(fluent::lint_exception);
                     if let Some(const_anon) = const_anon {

compiler/rustc_lint/src/non_local_def.rs

@@ -258,6 +258,13 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                     Some((cx.tcx.def_span(parent), may_move))
                 };
 
+                let macro_to_change =
+                    if let ExpnKind::Macro(kind, name) = item.span.ctxt().outer_expn_data().kind {
+                        Some((name.to_string(), kind.descr()))
+                    } else {
+                        None
+                    };
+
                 cx.emit_span_lint(
                     NON_LOCAL_DEFINITIONS,
                     ms,
@@ -274,6 +281,7 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                         move_to,
                         may_remove,
                         has_trait: impl_.of_trait.is_some(),
+                        macro_to_change,
                     },
                 )
             }

compiler/rustc_target/src/spec/base/redox.rs

@@ -1,4 +1,4 @@
-use crate::spec::{cvs, RelroLevel, TargetOptions};
+use crate::spec::{cvs, Cc, LinkerFlavor, Lld, RelroLevel, TargetOptions};
 
 pub fn opts() -> TargetOptions {
     TargetOptions {
@@ -12,6 +12,8 @@ pub fn opts() -> TargetOptions {
         has_thread_local: true,
         crt_static_default: true,
         crt_static_respected: true,
+        crt_static_allows_dylibs: true,
+        late_link_args: TargetOptions::link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-lgcc"]),
         ..Default::default()
     }
 }

compiler/rustc_target/src/spec/mod.rs

@@ -1647,6 +1647,7 @@ supported_targets! {
     ("x86_64-unknown-l4re-uclibc", x86_64_unknown_l4re_uclibc),
 
     ("aarch64-unknown-redox", aarch64_unknown_redox),
+    ("i686-unknown-redox", i686_unknown_redox),
     ("x86_64-unknown-redox", x86_64_unknown_redox),
 
     ("i386-apple-ios", i386_apple_ios),

compiler/rustc_target/src/spec/targets/i686_unknown_redox.rs

@@ -0,0 +1,27 @@
+use crate::spec::{base, Cc, LinkerFlavor, Lld, StackProbeType, Target};
+
+pub fn target() -> Target {
+    let mut base = base::redox::opts();
+    base.cpu = "pentiumpro".into();
+    base.plt_by_default = false;
+    base.max_atomic_width = Some(64);
+    base.add_pre_link_args(LinkerFlavor::Gnu(Cc::Yes, Lld::No), &["-m32"]);
+    // don't use probe-stack=inline-asm until rust#83139 and rust#84667 are resolved
+    base.stack_probes = StackProbeType::Call;
+
+    Target {
+        llvm_target: "i686-unknown-redox".into(),
+        metadata: crate::spec::TargetMetadata {
+            description: None,
+            tier: None,
+            host_tools: None,
+            std: None,
+        },
+        pointer_width: 32,
+        data_layout:
+            "e-m:e-p:32:32-p270:32:32-p271:32:32-p272:64:64-i128:128-f64:32:64-f80:32-n8:16:32-S128"
+                .into(),
+        arch: "x86".into(),
+        options: base,
+    }
+}

library/alloc/src/rc.rs

@@ -3516,7 +3516,7 @@ fn data_offset_align(align: usize) -> usize {
     layout.size() + layout.padding_needed_for(align)
 }
 
-/// A uniquely owned `Rc`
+/// A uniquely owned [`Rc`].
 ///
 /// This represents an `Rc` that is known to be uniquely owned -- that is, have exactly one strong
 /// reference. Multiple weak pointers can be created, but attempts to upgrade those to strong
@@ -3554,13 +3554,24 @@ fn data_offset_align(align: usize) -> usize {
 /// including fallible or async constructors.
 #[unstable(feature = "unique_rc_arc", issue = "112566")]
 #[derive(Debug)]
-pub struct UniqueRc<T> {
+pub struct UniqueRc<
+    T: ?Sized,
+    #[unstable(feature = "allocator_api", issue = "32838")] A: Allocator = Global,
+> {
     ptr: NonNull<RcBox<T>>,
     phantom: PhantomData<RcBox<T>>,
+    alloc: A,
 }
 
+#[unstable(feature = "unique_rc_arc", issue = "112566")]
+impl<T: ?Sized + Unsize<U>, U: ?Sized, A: Allocator> CoerceUnsized<UniqueRc<U, A>>
+    for UniqueRc<T, A>
+{
+}
+
+// Depends on A = Global
 impl<T> UniqueRc<T> {
-    /// Creates a new `UniqueRc`
+    /// Creates a new `UniqueRc`.
     ///
     /// Weak references to this `UniqueRc` can be created with [`UniqueRc::downgrade`]. Upgrading
     /// these weak references will fail before the `UniqueRc` has been converted into an [`Rc`].
@@ -3569,54 +3580,78 @@ impl<T> UniqueRc<T> {
     #[cfg(not(no_global_oom_handling))]
     #[unstable(feature = "unique_rc_arc", issue = "112566")]
     pub fn new(value: T) -> Self {
-        Self {
-            ptr: Box::leak(Box::new(RcBox {
+        Self::new_in(value, Global)
+    }
+}
+
+impl<T, A: Allocator> UniqueRc<T, A> {
+    /// Creates a new `UniqueRc` in the provided allocator.
+    ///
+    /// Weak references to this `UniqueRc` can be created with [`UniqueRc::downgrade`]. Upgrading
+    /// these weak references will fail before the `UniqueRc` has been converted into an [`Rc`].
+    /// After converting the `UniqueRc` into an [`Rc`], any weak references created beforehand will
+    /// point to the new [`Rc`].
+    #[cfg(not(no_global_oom_handling))]
+    #[unstable(feature = "unique_rc_arc", issue = "112566")]
+    pub fn new_in(value: T, alloc: A) -> Self {
+        let (ptr, alloc) = Box::into_unique(Box::new_in(
+            RcBox {
                 strong: Cell::new(0),
                 // keep one weak reference so if all the weak pointers that are created are dropped
                 // the UniqueRc still stays valid.
                 weak: Cell::new(1),
                 value,
-            }))
-            .into(),
-            phantom: PhantomData,
-        }
-    }
-
-    /// Creates a new weak reference to the `UniqueRc`
-    ///
-    /// Attempting to upgrade this weak reference will fail before the `UniqueRc` has been converted
-    /// to a [`Rc`] using [`UniqueRc::into_rc`].
-    #[unstable(feature = "unique_rc_arc", issue = "112566")]
-    pub fn downgrade(this: &Self) -> Weak<T> {
-        // SAFETY: This pointer was allocated at creation time and we guarantee that we only have
-        // one strong reference before converting to a regular Rc.
-        unsafe {
-            this.ptr.as_ref().inc_weak();
-        }
-        Weak { ptr: this.ptr, alloc: Global }
+            },
+            alloc,
+        ));
+        Self { ptr: ptr.into(), phantom: PhantomData, alloc }
     }
+}
 
-    /// Converts the `UniqueRc` into a regular [`Rc`]
+impl<T: ?Sized, A: Allocator> UniqueRc<T, A> {
+    /// Converts the `UniqueRc` into a regular [`Rc`].
     ///
     /// This consumes the `UniqueRc` and returns a regular [`Rc`] that contains the `value` that
     /// is passed to `into_rc`.
     ///
     /// Any weak references created before this method is called can now be upgraded to strong
     /// references.
     #[unstable(feature = "unique_rc_arc", issue = "112566")]
-    pub fn into_rc(this: Self) -> Rc<T> {
+    pub fn into_rc(this: Self) -> Rc<T, A> {
         let mut this = ManuallyDrop::new(this);
+
+        // Move the allocator out.
+        // SAFETY: `this.alloc` will not be accessed again, nor dropped because it is in
+        // a `ManuallyDrop`.
+        let alloc: A = unsafe { ptr::read(&this.alloc) };
+
         // SAFETY: This pointer was allocated at creation time so we know it is valid.
         unsafe {
             // Convert our weak reference into a strong reference
             this.ptr.as_mut().strong.set(1);
-            Rc::from_inner(this.ptr)
+            Rc::from_inner_in(this.ptr, alloc)
+        }
+    }
+}
+
+impl<T: ?Sized, A: Allocator + Clone> UniqueRc<T, A> {
+    /// Creates a new weak reference to the `UniqueRc`.
+    ///
+    /// Attempting to upgrade this weak reference will fail before the `UniqueRc` has been converted
+    /// to a [`Rc`] using [`UniqueRc::into_rc`].
+    #[unstable(feature = "unique_rc_arc", issue = "112566")]
+    pub fn downgrade(this: &Self) -> Weak<T, A> {
+        // SAFETY: This pointer was allocated at creation time and we guarantee that we only have
+        // one strong reference before converting to a regular Rc.
+        unsafe {
+            this.ptr.as_ref().inc_weak();
         }
+        Weak { ptr: this.ptr, alloc: this.alloc.clone() }
     }
 }
 
 #[unstable(feature = "unique_rc_arc", issue = "112566")]
-impl<T> Deref for UniqueRc<T> {
+impl<T: ?Sized, A: Allocator> Deref for UniqueRc<T, A> {
     type Target = T;
 
     fn deref(&self) -> &T {
@@ -3626,7 +3661,7 @@ impl<T> Deref for UniqueRc<T> {
 }
 
 #[unstable(feature = "unique_rc_arc", issue = "112566")]
-impl<T> DerefMut for UniqueRc<T> {
+impl<T: ?Sized, A: Allocator> DerefMut for UniqueRc<T, A> {
     fn deref_mut(&mut self) -> &mut T {
         // SAFETY: This pointer was allocated at creation time so we know it is valid. We know we
         // have unique ownership and therefore it's safe to make a mutable reference because
@@ -3636,7 +3671,7 @@ impl<T> DerefMut for UniqueRc<T> {
 }
 
 #[unstable(feature = "unique_rc_arc", issue = "112566")]
-unsafe impl<#[may_dangle] T> Drop for UniqueRc<T> {
+unsafe impl<#[may_dangle] T: ?Sized, A: Allocator> Drop for UniqueRc<T, A> {
     fn drop(&mut self) {
         unsafe {
             // destroy the contained object
@@ -3646,7 +3681,7 @@ unsafe impl<#[may_dangle] T> Drop for UniqueRc<T> {
             self.ptr.as_ref().dec_weak();
 
             if self.ptr.as_ref().weak() == 0 {
-                Global.deallocate(self.ptr.cast(), Layout::for_value_raw(self.ptr.as_ptr()));
+                self.alloc.deallocate(self.ptr.cast(), Layout::for_value_raw(self.ptr.as_ptr()));
             }
         }
     }

library/alloc/src/rc/tests.rs

@@ -606,6 +606,23 @@ fn test_unique_rc_drops_contents() {
     assert!(dropped);
 }
 
+/// Exercise the non-default allocator usage.
+#[test]
+fn test_unique_rc_with_alloc_drops_contents() {
+    let mut dropped = false;
+    struct DropMe<'a>(&'a mut bool);
+    impl Drop for DropMe<'_> {
+        fn drop(&mut self) {
+            *self.0 = true;
+        }
+    }
+    {
+        let rc = UniqueRc::new_in(DropMe(&mut dropped), std::alloc::System);
+        drop(rc);
+    }
+    assert!(dropped);
+}
+
 #[test]
 fn test_unique_rc_weak_clone_holding_ref() {
     let mut v = UniqueRc::new(0u8);
@@ -614,3 +631,12 @@ fn test_unique_rc_weak_clone_holding_ref() {
     let _ = w.clone(); // touch weak count
     *r = 123;
 }
+
+#[test]
+fn test_unique_rc_unsizing_coercion() {
+    let mut rc: UniqueRc<[u8]> = UniqueRc::new([0u8; 3]);
+    assert_eq!(rc.len(), 3);
+    rc[0] = 123;
+    let rc: Rc<[u8]> = UniqueRc::into_rc(rc);
+    assert_eq!(*rc, [123, 0, 0]);
+}

src/bootstrap/src/core/sanity.rs

@@ -40,6 +40,7 @@ pub struct Finder {
 #[cfg(not(feature = "bootstrap-self-test"))]
 const STAGE0_MISSING_TARGETS: &[&str] = &[
     // just a dummy comment so the list doesn't get onelined
+    "i686-unknown-redox",
 ];
 
 /// Minimum version threshold for libstdc++ required when using prebuilt LLVM
@@ -137,19 +138,20 @@ pub fn check(build: &mut Build) {
     }
 
     // We need cmake, but only if we're actually building LLVM or sanitizers.
-    let building_llvm = build
-        .hosts
-        .iter()
-        .map(|host| {
-            build.config.llvm_enabled(*host)
-                && build
-                    .config
-                    .target_config
-                    .get(host)
-                    .map(|config| config.llvm_config.is_none())
-                    .unwrap_or(true)
-        })
-        .any(|build_llvm_ourselves| build_llvm_ourselves);
+    let building_llvm = !build.config.llvm_from_ci
+        && build
+            .hosts
+            .iter()
+            .map(|host| {
+                build.config.llvm_enabled(*host)
+                    && build
+                        .config
+                        .target_config
+                        .get(host)
+                        .map(|config| config.llvm_config.is_none())
+                        .unwrap_or(true)
+            })
+            .any(|build_llvm_ourselves| build_llvm_ourselves);
 
     let need_cmake = building_llvm || build.config.any_sanitizers_to_build();
     if need_cmake && cmd_finder.maybe_have("cmake").is_none() {

src/ci/docker/host-x86_64/dist-i686-linux/Dockerfile

@@ -6,8 +6,12 @@ FROM centos:7
 
 WORKDIR /build
 
+# CentOS 7 EOL is June 30, 2024, but the repos remain in the vault.
+RUN sed -i /etc/yum.repos.d/*.repo -e 's!^mirrorlist!#mirrorlist!' \
+  -e 's!^#baseurl=http://mirror.centos.org/!baseurl=https://vault.centos.org/!'
+RUN sed -i 's/enabled=1/enabled=0/' /etc/yum/pluginconf.d/fastestmirror.conf
+
 RUN yum upgrade -y && \
-    yum install -y epel-release && \
     yum install -y \
       automake \
       bzip2 \