Rollup of 6 pull requests

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -17,6 +17,7 @@ use rustc_middle::mir::{
 };
 use rustc_middle::ty::adjustment::PointerCoercion;
 use rustc_middle::ty::{self, RegionVid, Ty, TyCtxt};
+use rustc_middle::util::CallKind;
 use rustc_span::{DesugaringKind, Span, Symbol, kw, sym};
 use rustc_trait_selection::error_reporting::traits::FindExprBySpan;
 use tracing::{debug, instrument};
@@ -635,6 +636,39 @@ impl<'tcx> MirBorrowckCtxt<'_, '_, 'tcx> {
                 // Used in a closure.
                 (LaterUseKind::ClosureCapture, capture_kind_span, Some(path_span))
             }
+            // In the case that the borrowed value (probably a temporary)
+            // overlaps with the method's receiver, then point at the method.
+            UseSpans::FnSelfUse {
+                var_span: span,
+                kind: CallKind::Normal { desugaring: None, .. },
+                ..
+            } if span
+                .overlaps(self.body.local_decls[borrow.assigned_place.local].source_info.span) =>
+            {
+                if let TerminatorKind::Call { func, call_source: CallSource::Normal, .. } =
+                    &self.body.basic_blocks[location.block].terminator().kind
+                {
+                    // Just point to the function, to reduce the chance of overlapping spans.
+                    let function_span = match func {
+                        Operand::Constant(c) => c.span,
+                        Operand::Copy(place) | Operand::Move(place) => {
+                            if let Some(l) = place.as_local() {
+                                let local_decl = &self.body.local_decls[l];
+                                if self.local_names[l].is_none() {
+                                    local_decl.source_info.span
+                                } else {
+                                    span
+                                }
+                            } else {
+                                span
+                            }
+                        }
+                    };
+                    (LaterUseKind::Call, function_span, None)
+                } else {
+                    (LaterUseKind::Other, span, None)
+                }
+            }
             UseSpans::PatUse(span)
             | UseSpans::OtherUse(span)
             | UseSpans::FnSelfUse { var_span: span, .. } => {

compiler/rustc_borrowck/src/diagnostics/mod.rs

@@ -661,9 +661,6 @@ impl UseSpans<'_> {
             UseSpans::ClosureUse { args_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
-                fn_call_span
-            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }
@@ -674,9 +671,6 @@ impl UseSpans<'_> {
             UseSpans::ClosureUse { path_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
-                fn_call_span
-            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }
@@ -687,9 +681,6 @@ impl UseSpans<'_> {
             UseSpans::ClosureUse { capture_kind_span: span, .. }
             | UseSpans::PatUse(span)
             | UseSpans::OtherUse(span) => span,
-            UseSpans::FnSelfUse { fn_call_span, kind: CallKind::DerefCoercion { .. }, .. } => {
-                fn_call_span
-            }
             UseSpans::FnSelfUse { var_span, .. } => var_span,
         }
     }

compiler/rustc_hir_analysis/src/impl_wf_check.rs

@@ -128,21 +128,7 @@ pub(crate) fn enforce_impl_lifetime_params_are_constrained(
     for param in &impl_generics.own_params {
         match param.kind {
             ty::GenericParamDefKind::Lifetime => {
-                let param_lt = cgp::Parameter::from(param.to_early_bound_region_data());
-                if lifetimes_in_associated_types.contains(&param_lt) // (*)
-                    && !input_parameters.contains(&param_lt)
-                {
-                    let mut diag = tcx.dcx().create_err(UnconstrainedGenericParameter {
-                        span: tcx.def_span(param.def_id),
-                        param_name: param.name,
-                        param_def_kind: tcx.def_descr(param.def_id),
-                        const_param_note: false,
-                        const_param_note2: false,
-                    });
-                    diag.code(E0207);
-                    res = Err(diag.emit());
-                }
-                // (*) This is a horrible concession to reality. I think it'd be
+                // This is a horrible concession to reality. I think it'd be
                 // better to just ban unconstrained lifetimes outright, but in
                 // practice people do non-hygienic macros like:
                 //
@@ -160,6 +146,20 @@ pub(crate) fn enforce_impl_lifetime_params_are_constrained(
                 // permit those, so long as the lifetimes aren't used in
                 // associated types. I believe this is sound, because lifetimes
                 // used elsewhere are not projected back out.
+                let param_lt = cgp::Parameter::from(param.to_early_bound_region_data());
+                if lifetimes_in_associated_types.contains(&param_lt)
+                    && !input_parameters.contains(&param_lt)
+                {
+                    let mut diag = tcx.dcx().create_err(UnconstrainedGenericParameter {
+                        span: tcx.def_span(param.def_id),
+                        param_name: param.name,
+                        param_def_kind: tcx.def_descr(param.def_id),
+                        const_param_note: false,
+                        const_param_note2: false,
+                    });
+                    diag.code(E0207);
+                    res = Err(diag.emit());
+                }
             }
             ty::GenericParamDefKind::Type { .. } | ty::GenericParamDefKind::Const { .. } => {
                 // Enforced in `enforce_impl_non_lifetime_params_are_constrained`.

compiler/rustc_lint/src/builtin.rs

@@ -1244,8 +1244,8 @@ impl<'tcx> LateLintPass<'tcx> for UngatedAsyncFnTrackCaller {
 
 declare_lint! {
     /// The `unreachable_pub` lint triggers for `pub` items not reachable from other crates - that
-    /// means neither directly accessible, nor reexported, nor leaked through things like return
-    /// types.
+    /// means neither directly accessible, nor reexported (with `pub use`), nor leaked through
+    /// things like return types (which the [`unnameable_types`] lint can detect if desired).
     ///
     /// ### Example
     ///
@@ -1272,8 +1272,10 @@ declare_lint! {
     /// intent that the item is only visible within its own crate.
     ///
     /// This lint is "allow" by default because it will trigger for a large
-    /// amount existing Rust code, and has some false-positives. Eventually it
+    /// amount of existing Rust code, and has some false-positives. Eventually it
     /// is desired for this to become warn-by-default.
+    ///
+    /// [`unnameable_types`]: #unnameable-types
     pub UNREACHABLE_PUB,
     Allow,
     "`pub` items not reachable from crate root"

compiler/rustc_lint_defs/src/builtin.rs

@@ -4362,7 +4362,7 @@ declare_lint! {
     /// ### Explanation
     ///
     /// It is often expected that if you can obtain an object of type `T`, then
-    /// you can name the type `T` as well, this lint attempts to enforce this rule.
+    /// you can name the type `T` as well; this lint attempts to enforce this rule.
     /// The recommended action is to either reexport the type properly to make it nameable,
     /// or document that users are not supposed to be able to name it for one reason or another.
     ///

compiler/rustc_middle/src/util/find_self_call.rs

@@ -17,26 +17,29 @@ pub fn find_self_call<'tcx>(
     debug!("find_self_call(local={:?}): terminator={:?}", local, body[block].terminator);
     if let Some(Terminator { kind: TerminatorKind::Call { func, args, .. }, .. }) =
         &body[block].terminator
+        && let Operand::Constant(box ConstOperand { const_, .. }) = func
+        && let ty::FnDef(def_id, fn_args) = *const_.ty().kind()
+        && let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
+            tcx.opt_associated_item(def_id)
+        && let [Spanned { node: Operand::Move(self_place) | Operand::Copy(self_place), .. }, ..] =
+            **args
     {
-        debug!("find_self_call: func={:?}", func);
-        if let Operand::Constant(box ConstOperand { const_, .. }) = func {
-            if let ty::FnDef(def_id, fn_args) = *const_.ty().kind() {
-                if let Some(ty::AssocItem { fn_has_self_parameter: true, .. }) =
-                    tcx.opt_associated_item(def_id)
-                {
-                    debug!("find_self_call: args={:?}", fn_args);
-                    if let [
-                        Spanned {
-                            node: Operand::Move(self_place) | Operand::Copy(self_place), ..
-                        },
-                        ..,
-                    ] = **args
-                    {
-                        if self_place.as_local() == Some(local) {
-                            return Some((def_id, fn_args));
-                        }
-                    }
-                }
+        if self_place.as_local() == Some(local) {
+            return Some((def_id, fn_args));
+        }
+
+        // Handle the case where `self_place` gets reborrowed.
+        // This happens when the receiver is `&T`.
+        for stmt in &body[block].statements {
+            if let StatementKind::Assign(box (place, rvalue)) = &stmt.kind
+                && let Some(reborrow_local) = place.as_local()
+                && self_place.as_local() == Some(reborrow_local)
+                && let Rvalue::Ref(_, _, deref_place) = rvalue
+                && let PlaceRef { local: deref_local, projection: [ProjectionElem::Deref] } =
+                    deref_place.as_ref()
+                && deref_local == local
+            {
+                return Some((def_id, fn_args));
             }
         }
     }

library/std/src/f128.rs

@@ -227,6 +227,7 @@ impl f128 {
     /// ```
     #[inline]
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fmaf128", alias = "fusedMultiplyAdd")]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub fn mul_add(self, a: f128, b: f128) -> f128 {
@@ -384,6 +385,7 @@ impl f128 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f128", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]

library/std/src/f16.rs

@@ -228,6 +228,7 @@ impl f16 {
     #[inline]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
+    #[doc(alias = "fmaf16", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     pub fn mul_add(self, a: f16, b: f16) -> f16 {
         unsafe { intrinsics::fmaf16(self, a, b) }
@@ -384,6 +385,7 @@ impl f16 {
     /// # }
     /// ```
     #[inline]
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[unstable(feature = "f16", issue = "116909")]
     #[must_use = "method returns a new number and does not mutate the original value"]

library/std/src/f32.rs

@@ -210,6 +210,7 @@ impl f32 {
     /// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
     /// ```
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fmaf", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -360,6 +361,7 @@ impl f32 {
     /// assert!(negative.sqrt().is_nan());
     /// assert!(negative_zero.sqrt() == negative_zero);
     /// ```
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]

library/std/src/f64.rs

@@ -210,6 +210,7 @@ impl f64 {
     /// assert_eq!(one_plus_eps * one_minus_eps + minus_one, 0.0);
     /// ```
     #[rustc_allow_incoherent_impl]
+    #[doc(alias = "fma", alias = "fusedMultiplyAdd")]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
@@ -360,6 +361,7 @@ impl f64 {
     /// assert!(negative.sqrt().is_nan());
     /// assert!(negative_zero.sqrt() == negative_zero);
     /// ```
+    #[doc(alias = "squareRoot")]
     #[rustc_allow_incoherent_impl]
     #[must_use = "method returns a new number and does not mutate the original value"]
     #[stable(feature = "rust1", since = "1.0.0")]

tests/ui/lifetimes/tail-expr-in-nested-expr.stderr

@@ -2,11 +2,10 @@ error[E0716]: temporary value dropped while borrowed
   --> $DIR/tail-expr-in-nested-expr.rs:4:15
    |
 LL |     let _ = { String::new().as_str() }.len();
-   |               ^^^^^^^^^^^^^---------
+   |               ^^^^^^^^^^^^^        -   --- borrow later used by call
    |               |                    |
    |               |                    temporary value is freed at the end of this statement
    |               creates a temporary value which is freed while still in use
-   |               borrow later used here
    |
    = note: consider using a `let` binding to create a longer lived value
 

tests/ui/lint/lint-const-item-mutation.stderr

@@ -75,10 +75,15 @@ warning: taking a mutable reference to a `const` item
   --> $DIR/lint-const-item-mutation.rs:42:5
    |
 LL |     (&mut MY_STRUCT).use_mut();
-   |     ^^^^^^^^^^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: each usage of a `const` item creates a new temporary
    = note: the mutable reference will refer to this temporary, not the original `const` item
+note: mutable reference created due to call to this method
+  --> $DIR/lint-const-item-mutation.rs:9:5
+   |
+LL |     fn use_mut(&mut self) {}
+   |     ^^^^^^^^^^^^^^^^^^^^^
 note: `const` item defined here
   --> $DIR/lint-const-item-mutation.rs:27:1
    |

tests/ui/moves/move-deref-coercion.stderr

@@ -4,7 +4,7 @@ error[E0382]: borrow of partially moved value: `val`
 LL |     let _val = val.first;
    |                --------- value partially moved here
 LL |     val.inner;
-   |     ^^^^^^^^^ value borrowed here after partial move
+   |     ^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `val.first` has type `NotCopy`, which does not implement the `Copy` trait
    = note: borrow occurs due to deref coercion to `NotCopy`
@@ -20,7 +20,7 @@ error[E0382]: borrow of partially moved value: `val`
 LL |     let _val = val.first;
    |                --------- value partially moved here
 LL |     val.inner_method();
-   |     ^^^^^^^^^^^^^^^^^^ value borrowed here after partial move
+   |     ^^^ value borrowed here after partial move
    |
    = note: partial move occurs because `val.first` has type `NotCopy`, which does not implement the `Copy` trait
    = note: borrow occurs due to deref coercion to `NotCopy`

tests/ui/no-capture-arc.stderr

@@ -1,5 +1,5 @@
 error[E0382]: borrow of moved value: `arc_v`
-  --> $DIR/no-capture-arc.rs:14:16
+  --> $DIR/no-capture-arc.rs:14:18
    |
 LL |     let arc_v = Arc::new(v);
    |         ----- move occurs because `arc_v` has type `Arc<Vec<i32>>`, which does not implement the `Copy` trait
@@ -10,7 +10,7 @@ LL |         assert_eq!((*arc_v)[3], 4);
    |                      ----- variable moved due to use in closure
 ...
 LL |     assert_eq!((*arc_v)[2], 3);
-   |                ^^^^^^^^ value borrowed here after move
+   |                  ^^^^^ value borrowed here after move
    |
    = note: borrow occurs due to deref coercion to `Vec<i32>`
 

tests/ui/no-reuse-move-arc.stderr

@@ -1,5 +1,5 @@
 error[E0382]: borrow of moved value: `arc_v`
-  --> $DIR/no-reuse-move-arc.rs:12:16
+  --> $DIR/no-reuse-move-arc.rs:12:18
    |
 LL |     let arc_v = Arc::new(v);
    |         ----- move occurs because `arc_v` has type `Arc<Vec<i32>>`, which does not implement the `Copy` trait
@@ -10,7 +10,7 @@ LL |         assert_eq!((*arc_v)[3], 4);
    |                      ----- variable moved due to use in closure
 ...
 LL |     assert_eq!((*arc_v)[2], 3);
-   |                ^^^^^^^^ value borrowed here after move
+   |                  ^^^^^ value borrowed here after move
    |
    = note: borrow occurs due to deref coercion to `Vec<i32>`
 

triagebot.toml

@@ -498,6 +498,11 @@ trigger_files = [
     "src/tools/compiletest"
 ]
 
+[autolabel."A-rustc-dev-guide"]
+trigger_files = [
+    "src/doc/rustc-dev-guide",
+]
+
 [notify-zulip."I-prioritize"]
 zulip_stream = 245100 # #t-compiler/wg-prioritization/alerts
 topic = "#{number} {title}"
@@ -990,6 +995,10 @@ https://github.com/rust-lang/reference/blob/HEAD/src/identifiers.md.
 """
 cc = ["@ehuss"]
 
+[mentions."src/doc/rustc-dev-guide"]
+message = "The rustc-dev-guide subtree was changed. If this PR *only* touches the dev guide consider submitting a PR directly to [rust-lang/rustc-dev-guide](https://github.com/rust-lang/rustc-dev-guide/pulls) otherwise thank you for updating the dev guide with your changes."
+cc = ["@BoxyUwU", "@jieyouxu", "@kobzol"]
+
 [assign]
 warn_non_default_branch.enable = true
 contributing_url = "https://rustc-dev-guide.rust-lang.org/getting-started.html"
@@ -1208,7 +1217,7 @@ project-exploit-mitigations = [
 "/src/doc/nomicon" =                                     ["@ehuss"]
 "/src/doc/reference" =                                   ["@ehuss"]
 "/src/doc/rust-by-example" =                             ["@ehuss"]
-"/src/doc/rustc-dev-guide" =                             ["@kobzol", "@jieyouxu"]
+"/src/doc/rustc-dev-guide" =                             ["compiler"]
 "/src/doc/rustdoc" =                                     ["rustdoc"]
 "/src/doc/style-guide" =                                 ["style-team"]
 "/src/etc" =                                             ["@Mark-Simulacrum"]