Auto merge of rust-lang#129979 - matthiaskrgr:rollup-ig5r2wg, r=matth…

…iaskrgr

Rollup of 12 pull requests

Successful merges:

 - rust-lang#128919 (Add an internal lint that warns when accessing untracked data)
 - rust-lang#129471 ([rustdoc] Sort impl associated items by kinds and then by appearance)
 - rust-lang#129653 (clarify that addr_of creates read-only pointers)
 - rust-lang#129775 (bootstrap: Try to track down why `initial_libdir` sometimes fails)
 - rust-lang#129939 (explain why Rvalue::Len still exists)
 - rust-lang#129940 (s390x: Fix a regression related to backchain feature)
 - rust-lang#129942 (copy rustc rustlib artifacts from ci-rustc)
 - rust-lang#129943 (use the bootstrapped compiler for `test-float-parse` test)
 - rust-lang#129944 (Add compat note for trait solver change)
 - rust-lang#129947 (Add digit separators in `Duration` examples)
 - rust-lang#129955 (Temporarily remove fmease from the review rotation)
 - rust-lang#129957 (forward linker option to lint-docs)

r? `@ghost`
`@rustbot` modify labels: rollup

RELEASES.md

@@ -100,6 +100,9 @@ Compatibility Notes
   The reason is that these types have different roles: `std::panic::PanicHookInfo` is the argument to the [panic hook](https://doc.rust-lang.org/stable/std/panic/fn.set_hook.html) in std context (where panics can have an arbitrary payload), while `core::panic::PanicInfo` is the argument to the [`#[panic_handler]`](https://doc.rust-lang.org/nomicon/panic-handler.html) in no_std context (where panics always carry a formatted *message*). Separating these types allows us to add more useful methods to these types, such as `std::panic::PanicHookInfo::payload_as_str()` and `core::panic::PanicInfo::message()`.
 
 * The new sort implementations may panic if a type's implementation of [`Ord`](https://doc.rust-lang.org/std/cmp/trait.Ord.html) (or the given comparison function) does not implement a [total order](https://en.wikipedia.org/wiki/Total_order) as the trait requires. `Ord`'s supertraits (`PartialOrd`, `Eq`, and `PartialEq`) must also be consistent. The previous implementations would not "notice" any problem, but the new implementations have a good chance of detecting inconsistencies, throwing a panic rather than returning knowingly unsorted data.
+* [In very rare cases, a change in the internal evaluation order of the trait
+  solver may result in new fatal overflow errors.](https://github.com/rust-lang/rust/pull/126128)
+
 
 <a id="1.81.0-Internal-Changes"></a>
 

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -353,9 +353,7 @@ pub fn target_features(sess: &Session, allow_unstable: bool) -> Vec<Symbol> {
                 None
             }
         })
-        .filter(|feature| {
-            RUSTC_SPECIAL_FEATURES.contains(feature) || features.contains(&Symbol::intern(feature))
-        })
+        .filter(|feature| features.contains(&Symbol::intern(feature)))
         .map(|feature| Symbol::intern(feature))
         .collect()
 }

compiler/rustc_data_structures/src/steal.rs

@@ -57,6 +57,7 @@ impl<T> Steal<T> {
     ///
     /// This should not be used within rustc as it leaks information not tracked
     /// by the query system, breaking incremental compilation.
+    #[cfg_attr(not(bootstrap), rustc_lint_untracked_query_information)]
     pub fn is_stolen(&self) -> bool {
         self.value.borrow().is_none()
     }

compiler/rustc_feature/src/builtin_attrs.rs

@@ -793,6 +793,12 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
         rustc_lint_query_instability, Normal, template!(Word),
         WarnFollowing, EncodeCrossCrate::Yes, INTERNAL_UNSTABLE
     ),
+    // Used by the `rustc::untracked_query_information` lint to warn methods which
+    // might not be stable during incremental compilation.
+    rustc_attr!(
+        rustc_lint_untracked_query_information, Normal, template!(Word),
+        WarnFollowing, EncodeCrossCrate::Yes, INTERNAL_UNSTABLE
+    ),
     // Used by the `rustc::diagnostic_outside_of_impl` lints to assist in changes to diagnostic
     // APIs. Any function with this attribute will be checked by that lint.
     rustc_attr!(

compiler/rustc_lint/messages.ftl

@@ -699,6 +699,9 @@ lint_ptr_null_checks_ref = references are not nullable, so checking them for nul
 lint_query_instability = using `{$query}` can result in unstable query results
     .note = if you believe this case to be fine, allow this lint and add a comment explaining your rationale
 
+lint_query_untracked = `{$method}` accesses information that is not tracked by the query system
+    .note = if you believe this case to be fine, allow this lint and add a comment explaining your rationale
+
 lint_range_endpoint_out_of_range = range endpoint is out of range for `{$ty}`
 
 lint_range_use_inclusive_range = use an inclusive range instead

compiler/rustc_lint/src/internal.rs

@@ -17,8 +17,8 @@ use tracing::debug;
 
 use crate::lints::{
     BadOptAccessDiag, DefaultHashTypesDiag, DiagOutOfImpl, LintPassByHand, NonExistentDocKeyword,
-    NonGlobImportTypeIrInherent, QueryInstability, SpanUseEqCtxtDiag, TyQualified, TykindDiag,
-    TykindKind, TypeIrInherentUsage, UntranslatableDiag,
+    NonGlobImportTypeIrInherent, QueryInstability, QueryUntracked, SpanUseEqCtxtDiag, TyQualified,
+    TykindDiag, TykindKind, TypeIrInherentUsage, UntranslatableDiag,
 };
 use crate::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext};
 
@@ -88,7 +88,18 @@ declare_tool_lint! {
     report_in_external_macro: true
 }
 
-declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY]);
+declare_tool_lint! {
+    /// The `untracked_query_information` lint detects use of methods which leak information not
+    /// tracked by the query system, such as whether a `Steal<T>` value has already been stolen. In
+    /// order not to break incremental compilation, such methods must be used very carefully or not
+    /// at all.
+    pub rustc::UNTRACKED_QUERY_INFORMATION,
+    Allow,
+    "require explicit opt-in when accessing information not tracked by the query system",
+    report_in_external_macro: true
+}
+
+declare_lint_pass!(QueryStability => [POTENTIAL_QUERY_INSTABILITY, UNTRACKED_QUERY_INFORMATION]);
 
 impl LateLintPass<'_> for QueryStability {
     fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) {
@@ -102,6 +113,13 @@ impl LateLintPass<'_> for QueryStability {
                     QueryInstability { query: cx.tcx.item_name(def_id) },
                 );
             }
+            if cx.tcx.has_attr(def_id, sym::rustc_lint_untracked_query_information) {
+                cx.emit_span_lint(
+                    UNTRACKED_QUERY_INFORMATION,
+                    span,
+                    QueryUntracked { method: cx.tcx.item_name(def_id) },
+                );
+            }
         }
     }
 }

compiler/rustc_lint/src/lib.rs

@@ -609,6 +609,7 @@ fn register_internals(store: &mut LintStore) {
         vec![
             LintId::of(DEFAULT_HASH_TYPES),
             LintId::of(POTENTIAL_QUERY_INSTABILITY),
+            LintId::of(UNTRACKED_QUERY_INFORMATION),
             LintId::of(USAGE_OF_TY_TYKIND),
             LintId::of(PASS_BY_VALUE),
             LintId::of(LINT_PASS_IMPL_WITHOUT_MACRO),

compiler/rustc_lint/src/lints.rs

@@ -894,6 +894,13 @@ pub(crate) struct QueryInstability {
     pub query: Symbol,
 }
 
+#[derive(LintDiagnostic)]
+#[diag(lint_query_untracked)]
+#[note]
+pub(crate) struct QueryUntracked {
+    pub method: Symbol,
+}
+
 #[derive(LintDiagnostic)]
 #[diag(lint_span_use_eq_ctxt)]
 pub(crate) struct SpanUseEqCtxtDiag;

compiler/rustc_middle/src/mir/syntax.rs

@@ -1307,6 +1307,9 @@ pub enum Rvalue<'tcx> {
     /// If the type of the place is an array, this is the array length. For slices (`[T]`, not
     /// `&[T]`) this accesses the place's metadata to determine the length. This rvalue is
     /// ill-formed for places of other types.
+    ///
+    /// This cannot be a `UnOp(PtrMetadata, _)` because that expects a value, and we only
+    /// have a place, and `UnOp(PtrMetadata, RawPtr(place))` is not a thing.
     Len(Place<'tcx>),
 
     /// Performs essentially all of the casts that can be performed via `as`.

compiler/rustc_passes/src/check_attr.rs

@@ -125,7 +125,9 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                 [sym::inline, ..] => self.check_inline(hir_id, attr, span, target),
                 [sym::coverage, ..] => self.check_coverage(attr, span, target),
                 [sym::optimize, ..] => self.check_optimize(hir_id, attr, target),
-                [sym::no_sanitize, ..] => self.check_no_sanitize(hir_id, attr, span, target),
+                [sym::no_sanitize, ..] => {
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                }
                 [sym::non_exhaustive, ..] => self.check_non_exhaustive(hir_id, attr, span, target),
                 [sym::marker, ..] => self.check_marker(hir_id, attr, span, target),
                 [sym::target_feature, ..] => {
@@ -166,10 +168,13 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
                     self.check_rustc_legacy_const_generics(hir_id, attr, span, target, item)
                 }
                 [sym::rustc_lint_query_instability, ..] => {
-                    self.check_rustc_lint_query_instability(hir_id, attr, span, target)
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
+                }
+                [sym::rustc_lint_untracked_query_information, ..] => {
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }
                 [sym::rustc_lint_diagnostics, ..] => {
-                    self.check_rustc_lint_diagnostics(hir_id, attr, span, target)
+                    self.check_applied_to_fn_or_method(hir_id, attr, span, target)
                 }
                 [sym::rustc_lint_opt_ty, ..] => self.check_rustc_lint_opt_ty(attr, span, target),
                 [sym::rustc_lint_opt_deny_field_access, ..] => {
@@ -452,11 +457,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    /// Checks that `#[no_sanitize(..)]` is applied to a function or method.
-    fn check_no_sanitize(&self, hir_id: HirId, attr: &Attribute, span: Span, target: Target) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
     fn check_generic_attr(
         &self,
         hir_id: HirId,
@@ -1635,30 +1635,6 @@ impl<'tcx> CheckAttrVisitor<'tcx> {
         }
     }
 
-    /// Checks that the `#[rustc_lint_query_instability]` attribute is only applied to a function
-    /// or method.
-    fn check_rustc_lint_query_instability(
-        &self,
-        hir_id: HirId,
-        attr: &Attribute,
-        span: Span,
-        target: Target,
-    ) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
-    /// Checks that the `#[rustc_lint_diagnostics]` attribute is only applied to a function or
-    /// method.
-    fn check_rustc_lint_diagnostics(
-        &self,
-        hir_id: HirId,
-        attr: &Attribute,
-        span: Span,
-        target: Target,
-    ) {
-        self.check_applied_to_fn_or_method(hir_id, attr, span, target)
-    }
-
     /// Checks that the `#[rustc_lint_opt_ty]` attribute is only applied to a struct.
     fn check_rustc_lint_opt_ty(&self, attr: &Attribute, span: Span, target: Target) {
         match target {

compiler/rustc_span/src/symbol.rs

@@ -1653,6 +1653,7 @@ symbols! {
         rustc_lint_opt_deny_field_access,
         rustc_lint_opt_ty,
         rustc_lint_query_instability,
+        rustc_lint_untracked_query_information,
         rustc_macro_transparency,
         rustc_main,
         rustc_mir,

library/core/src/ptr/mod.rs

@@ -2277,6 +2277,14 @@ impl<F: FnPtr> fmt::Debug for F {
 /// `addr_of!(expr)` is equivalent to `&raw const expr`. The macro is *soft-deprecated*;
 /// use `&raw const` instead.
 ///
+/// It is still an open question under which conditions writing through an `addr_of!`-created
+/// pointer is permitted. If the place `expr` evaluates to is based on a raw pointer, then the
+/// result of `addr_of!` inherits all permissions from that raw pointer. However, if the place is
+/// based on a reference, local variable, or `static`, then until all details are decided, the same
+/// rules as for shared references apply: it is UB to write through a pointer created with this
+/// operation, except for bytes located inside an `UnsafeCell`. Use `&raw mut` (or [`addr_of_mut`])
+/// to create a raw pointer that definitely permits mutation.
+///
 /// Creating a reference with `&`/`&mut` is only allowed if the pointer is properly aligned
 /// and points to initialized data. For cases where those requirements do not hold,
 /// raw pointers should be used instead. However, `&expr as *const _` creates a reference

library/core/src/time.rs

@@ -250,7 +250,7 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::from_millis(2569);
+    /// let duration = Duration::from_millis(2_569);
     ///
     /// assert_eq!(2, duration.as_secs());
     /// assert_eq!(569_000_000, duration.subsec_nanos());
@@ -279,7 +279,7 @@ impl Duration {
     /// let duration = Duration::from_micros(1_000_002);
     ///
     /// assert_eq!(1, duration.as_secs());
-    /// assert_eq!(2000, duration.subsec_nanos());
+    /// assert_eq!(2_000, duration.subsec_nanos());
     /// ```
     #[stable(feature = "duration_from_micros", since = "1.27.0")]
     #[must_use]
@@ -472,7 +472,7 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::new(5, 730023852);
+    /// let duration = Duration::new(5, 730_023_852);
     /// assert_eq!(duration.as_secs(), 5);
     /// ```
     ///
@@ -501,7 +501,7 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::from_millis(5432);
+    /// let duration = Duration::from_millis(5_432);
     /// assert_eq!(duration.as_secs(), 5);
     /// assert_eq!(duration.subsec_millis(), 432);
     /// ```
@@ -547,7 +547,7 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::from_millis(5010);
+    /// let duration = Duration::from_millis(5_010);
     /// assert_eq!(duration.as_secs(), 5);
     /// assert_eq!(duration.subsec_nanos(), 10_000_000);
     /// ```
@@ -566,8 +566,8 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::new(5, 730023852);
-    /// assert_eq!(duration.as_millis(), 5730);
+    /// let duration = Duration::new(5, 730_023_852);
+    /// assert_eq!(duration.as_millis(), 5_730);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
     #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
@@ -584,8 +584,8 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::new(5, 730023852);
-    /// assert_eq!(duration.as_micros(), 5730023);
+    /// let duration = Duration::new(5, 730_023_852);
+    /// assert_eq!(duration.as_micros(), 5_730_023);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
     #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
@@ -602,8 +602,8 @@ impl Duration {
     /// ```
     /// use std::time::Duration;
     ///
-    /// let duration = Duration::new(5, 730023852);
-    /// assert_eq!(duration.as_nanos(), 5730023852);
+    /// let duration = Duration::new(5, 730_023_852);
+    /// assert_eq!(duration.as_nanos(), 5_730_023_852);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
     #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
@@ -879,7 +879,7 @@ impl Duration {
     /// use std::time::Duration;
     ///
     /// let dur = Duration::new(2, 345_678_000);
-    /// assert_eq!(dur.as_millis_f64(), 2345.678);
+    /// assert_eq!(dur.as_millis_f64(), 2_345.678);
     /// ```
     #[unstable(feature = "duration_millis_float", issue = "122451")]
     #[must_use]
@@ -900,7 +900,7 @@ impl Duration {
     /// use std::time::Duration;
     ///
     /// let dur = Duration::new(2, 345_678_000);
-    /// assert_eq!(dur.as_millis_f32(), 2345.678);
+    /// assert_eq!(dur.as_millis_f32(), 2_345.678);
     /// ```
     #[unstable(feature = "duration_millis_float", issue = "122451")]
     #[must_use]
@@ -1017,7 +1017,7 @@ impl Duration {
     ///
     /// let dur = Duration::new(2, 700_000_000);
     /// assert_eq!(dur.mul_f32(3.14), Duration::new(8, 478_000_641));
-    /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847800, 0));
+    /// assert_eq!(dur.mul_f32(3.14e5), Duration::new(847_800, 0));
     /// ```
     #[stable(feature = "duration_float", since = "1.38.0")]
     #[must_use = "this returns the result of the operation, \

src/bootstrap/src/core/build_steps/compile.rs

@@ -931,7 +931,12 @@ impl Step for Rustc {
         // NOTE: the ABI of the beta compiler is different from the ABI of the downloaded compiler,
         // so its artifacts can't be reused.
         if builder.download_rustc() && compiler.stage != 0 {
-            builder.ensure(Sysroot { compiler, force_recompile: false });
+            let sysroot = builder.ensure(Sysroot { compiler, force_recompile: false });
+            cp_rustc_component_to_ci_sysroot(
+                builder,
+                &sysroot,
+                builder.config.ci_rustc_dev_contents(),
+            );
             return compiler.stage;
         }
 

src/bootstrap/src/core/build_steps/doc.rs

@@ -1186,6 +1186,9 @@ impl Step for RustcBook {
         cmd.arg("--rustc");
         cmd.arg(&rustc);
         cmd.arg("--rustc-target").arg(self.target.rustc_target_arg());
+        if let Some(target_linker) = builder.linker(self.target) {
+            cmd.arg("--rustc-linker").arg(target_linker);
+        }
         if builder.is_verbose() {
             cmd.arg("--verbose");
         }

src/bootstrap/src/core/build_steps/test.rs

@@ -3526,11 +3526,13 @@ impl Step for TestFloatParse {
 
     fn run(self, builder: &Builder<'_>) {
         let bootstrap_host = builder.config.build;
-        let compiler = builder.compiler(0, bootstrap_host);
+        let compiler = builder.compiler(builder.top_stage, bootstrap_host);
         let path = self.path.to_str().unwrap();
         let crate_name = self.path.components().last().unwrap().as_os_str().to_str().unwrap();
 
-        builder.ensure(compile::Std::new(compiler, self.host));
+        if !builder.download_rustc() {
+            builder.ensure(compile::Std::new(compiler, self.host));
+        }
 
         // Run any unit tests in the crate
         let cargo_test = tool::prepare_tool_cargo(

src/bootstrap/src/lib.rs

@@ -332,14 +332,20 @@ impl Build {
         .trim()
         .to_string();
 
-        let initial_libdir = initial_target_dir
-            .parent()
-            .unwrap()
-            .parent()
-            .unwrap()
-            .strip_prefix(&initial_sysroot)
-            .unwrap()
-            .to_path_buf();
+        // FIXME(Zalathar): Determining this path occasionally fails locally for
+        // unknown reasons, so we print some extra context to help track down why.
+        let find_initial_libdir = || {
+            let initial_libdir =
+                initial_target_dir.parent()?.parent()?.strip_prefix(&initial_sysroot).ok()?;
+            Some(initial_libdir.to_path_buf())
+        };
+        let Some(initial_libdir) = find_initial_libdir() else {
+            panic!(
+                "couldn't determine `initial_libdir` \
+                from target dir {initial_target_dir:?} \
+                and sysroot {initial_sysroot:?}"
+            )
+        };
 
         let version = std::fs::read_to_string(src.join("src").join("version"))
             .expect("failed to read src/version");